Classifications

• • 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
  • C09D167/00—Coating compositions based on polyesters obtained by reactions forming a carboxylic ester link in the main chain; Coating compositions based on derivatives of such polymers
  • C09D167/04—Polyesters derived from hydroxycarboxylic acids, e.g. lactones
• • 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
  • C09D17/00—Pigment pastes, e.g. for mixing in paints
• • 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
  • C09D167/00—Coating compositions based on polyesters obtained by reactions forming a carboxylic ester link in the main chain; Coating compositions based on derivatives of such polymers
• • 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
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
  • C09D5/02—Emulsion paints including aerosols

Definitions

• the present invention relates to the use of an aqueous dispersion of at least one biodegradable polymer containing at least one stabilizing agent, for the preparation of an aqueous film-forming composition with high dry matter.
• the invention relates more particularly to the use of the film-forming composition thus obtained for the preparation of aqueous adhesive compositions and aqueous pigment compositions.
• aqueous film-forming composition means a composition capable of forming a film or a film by leaving the water initially contained in said composition.
• aqueous adhesive composition means an aqueous film-forming composition capable of adhering to a support or of creating a seal between two other materials, whether it is of the same or different nature. It may in particular be a temporary protective composition for metal sheets, a varnish for wood, an anti-graffiti composition, a waterproofing composition for walls, a priming composition or textile sizing, of a coating composition for fertilizers, pharmaceuticals or seeds, or even an adhesive for leathers, papers, wood, textile materials (woven or not), synthetic fibers, plastics, glasses and other materials.
• Such aqueous adhesive compositions have variable water contents, generally between 30 and 95% of the total weight of these compositions.
• Water plays the role of solvent or inert dispersant of the constituents of these compositions and generally makes it possible to adjust the viscosity and the rheology of these compositions in order to allow their easy application on the surface or the material to be coated or glued, by coating, casting, spraying, soaking, immersion or by using brushes, rollers, plates or other instruments.
• Such adhesive compositions essentially comprise binders and adjuvants, in the state dissolved in water or simply dispersed in water.
• aqueous pigment composition also means a film-forming composition in the form of an aqueous suspension of pigments, binders and adjuvants. They may in particular be coating sauces, aqueous paints and aqueous pigment film-forming preparations, such as for example charged adhesives.
• aqueous pigment composition is responsible for the finished appearance of the paper (opaque, white, smooth and shiny) and is responsible for its suitability for printing and in particular for printing. color.
• Water is an essential component of the pigment composition because it generally constitutes 30% and up to 95% of the total weight of said pigment compositions. It is the vector of all the other elements.
• the pigments constitute the solid charge of said aqueous pigment composition.
• the pigments generally constitute 80 to 92% by weight of the dry matter (MS) of the aqueous pigment composition and generally have the role of covering the fibers of the paper or of imparting to them a smoothness, provide optical properties (whiteness, opacity, gloss) or properties printing (in the case of coating sauce or coating film).
• MS dry matter
• the amounts of pigments generally represent from 10 to 95% by weight of the dry matter of the aqueous pigment composition, and more generally from 35 to 95% by weight of the dry matter, according to the types of formulations selected (matt, satin or gloss paints).
• the adjuvants are, for their part, auxiliary products, present in the aqueous film-forming compositions, whether pigmentary or adhesive, only in small quantities.
• These additives introduced in fact generally represent from 0.3 to 5%, or even from 1 to 3% by weight of the dry matter of said aqueous film-forming composition. They are generally classified into three categories.
• the first category corresponds to formulating agents such as alkaline agents, dispersing agents (sodium hexa etaphosphate, sodium polyacrylate), wetting agents, defoamers (mineral oils, silicone products, fatty acid esters, fatty amines), biocides (ammonium quaternary, phenols, aldehydes, dyes).
• alkaline agents dispersing agents (sodium hexa etaphosphate, sodium polyacrylate), wetting agents, defoamers (mineral oils, silicone products, fatty acid esters, fatty amines), biocides (ammonium quaternary, phenols, aldehydes, dyes).
• the second category gives said film-forming composition the ability to behave well on machines: these are rheology-modifying agents (such as cellulose compounds, polyurethane thickeners), water retentants (Carboxy Methyl Cellulose, starches and derivatives, caseins, proteins, polyols) or lubricants (calcium stearate, sulfonated oils, polyols).
• rheology-modifying agents such as cellulose compounds, polyurethane thickeners
• water retentants Carboxy Methyl Cellulose, starches and derivatives, caseins, proteins, polyols
• lubricants calcium stearate, sulfonated oils, polyols.
• the third category makes it possible to improve or adjust the final characteristics of the aqueous film-forming composition: these can be insolubilizers (resins and crosslinking agents such as urea formaldehyde, melamine formaldehyde, glyoxal, zirconium salt), optical brighteners (derivatives of stilbene di, tetra or hexon sulfonated), coalescing agents or tinting dyes (helio violet BNZ, uniperse blue).
• insolubilizers resins and crosslinking agents such as urea formaldehyde, melamine formaldehyde, glyoxal, zirconium salt
• optical brighteners derivatives of stilbene di, tetra or hexon sulfonated
• coalescing agents or tinting dyes helio violet BNZ, uniperse blue
• the last constituent elements of the aqueous film-forming composition are the binders, which generally represent: - from 5 to 20% of the dry matter of the aqueous film-forming composition in the case of sauces coating, - from 5 to 90% of the dry matter of the aqueous film-forming composition in the case of aqueous pigment film-forming preparations, such as charged adhesives, - and from 5 to 65% of the dry matter of the aqueous film-forming composition in the paint, depending on whether it is matt, satin or glossy.
• Their role is in particular to ensure the cohesion of the pigment layer, of the film or of the film, obtained following the departure of the water.
• binders used are usually of natural origin, eg starch (wheat, corn), protein (casein), or of synthetic origin, eg latex or polyvinyl alcohol. More particularly, a latex (or “aqueous polymer dispersion”) is used which corresponds to a colloidal dispersion of synthetic polymers in an aqueous phase, ie a dispersion of microparticles of polymers in suspension in an aqueous phase, sometimes also called suspension or emulsion of polymers.
• the conventional manufacture of an aqueous dispersion of synthetic polymers is mainly based on processes for direct emulsion polymerization of synthetic monomers.
• This type of latex generally comprises particles of polymers synthesized by direct emulsion polymerization of the pairs of monomers, for example of the styrene / butadiene, styrene / butyl acrylate, methyl metacrylate / butadiene or vinyl acetate / butyl acrylate type.
• each of these monomers gives the latex properties of: - stiffness, gloss, absorption of inks (in the case of styrene, acrylonitrile, methyl metacrylate) resistance to solvents and oils (with acrylonitrile) - resistance UV aging (with methyl methacrylate, butyl acrylate, butadiene) - porosity (with vinyl acetate) binding power, flexibility (with butyl acrylate, butadiene).
• a synthetic latex thus used in a film-forming composition has a dry matter of 45 to 60%, a density close to 1, a viscosity
• the starch is biodegradable, it has a poorer binding power and is sensitive to water, which is particularly troublesome for the application of the film-forming composition, for example in multi-color "offset" printing where water is applied at each station, in water engravings or in flexography inks.
• aqueous dispersions of polymers prepared from biodegradable polymers were then the subject of intensive research and development.
• biodegradable polymer means a polymer capable of being degraded under the action of microorganisms, in particular by soil microorganisms, but also under the action of natural agents, in particular water.
• Such aqueous dispersions of biodegradable polymers are known, but can generally be obtained only by the use of volatile organic solvents as for example described in patent application JP 10-101911 and US patent 5,747,584. More particularly, in US Pat. No. 5,747,584, the use of aqueous dispersions of biodegradable polymers of the PHA type is described in particular for formulating adhesive dispersions which can be used for bonding nonwovens. However, such aqueous dispersions are always prepared using toluene, ethyl acetate, acetone, halogenated solvents or other suitable volatile organic solvents.
• volatile organic compound any organic compound having a vapor pressure of 10 Pa or more at a temperature of 25 ° C or having a corresponding volatility under given conditions.
• aqueous dispersions of at least one biodegradable polymer devoid of volatile organic solvents.
• the first type of prior art process consists in the manufacture by extrusion of a dispersion • biodegradable polyester with high dry matter (MS) and • very high viscosity.
• Patent application EP 1,302,502 proposes in this sense a process consisting in treating at high temperature and high pressure, by such an extrusion process, a mixture of biodegradable polyesters in the molten state with an aqueous emulsifier having a certain surface tension and with certain additives, so as to obtain an aqueous dispersion having a DM of at least 40% and a viscosity of at least 1,000 mPa.s and preferably between 1,500 and 10,000 mPa.s.
• the process consists in melting the biodegradable polyesters in the extruder, then in introducing the aqueous emulsifier there downstream of the molten mixture.
• the mixture is then kneaded at a temperature less than or equal to 100 ° C.
• Patent application O 97/49762 also describes an aqueous dispersion of biodegradable polymers capable of being obtained by extrusion, which contains starches modified by esterification, dispersed in an aqueous phase, and a solvent-free process for manufacturing said aqueous dispersions.
• the process consists in preparing a mixture in the molten phase, at a temperature of 100 to 180 ° C. of possible polymers and plasticizers, then in keeping this mixture under stirring at high temperature, before gradually adding water and agents dispersants.
• the second type of process of the state of the art making it possible to have aqueous dispersions of at least one biodegradable polymer, devoid of volatile organic solvents is that proposed by the Applicant company, and consists of aqueous dispersions of at least a biodegradable polymer constituted by an organic phase dispersed in an aqueous dispersing phase and devoid of volatile organic compounds, the dispersed organic phase of which comprises at least one viscosity reducing agent.
• These aqueous dispersions of at least one biodegradable polymer have been the subject of a patent application not yet examined, filed in France by the applicant company on September 12, 2003.
• aqueous dispersions of at least one biodegradable polymer contain an agent viscosity reducer having particular characteristics in terms of solubility parameter and capacity to form hydrogen bonds, used in a specific weight ratio with said biodegradable polymer.
• the viscosity reducing agent is here a heavy organic compound preferably biodegradable or compostable, which, incorporated into polymers, at least partially destroys the interactions between the chains responsible for the high viscosity and for the mechanical cohesion of said polymers.
• aqueous dispersions of at least one polyhydroxyalkanoate bacterial biodegradable polymer, stability variable, from microorganisms containing them.
• PHO is explained by the persistence around the polymer granules in suspension of residues of a particular protein, in this case here the mure.
• This type of process is also known for obtaining aqueous dispersions of biodegradable polymers of microbial origin other than PHO, such as, for example, copolymers of hydroxy valerate and hydroxy butyrate (PHBV).
• aqueous dispersions of biodegradable polymers devoid of volatile organic solvents, as binders in aqueous film-forming compositions, has above all been developed in the prior art with these aqueous dispersions of biodegradable polymers isolated from microbial strains.
• Patent application WO 91 / 13.207 indeed describes aqueous dispersions comprising a colloidal suspension in water of essentially amorphous particles of a polymer or of a copolymer of ⁇ -hydroxyalkanoates (for example ⁇ -hydroxybutyrate and ⁇ - hydroxyvalerate), extracted in particular from the biomass of Alcaligenes eutrophus or Pseudomonas oleovorans and its use to produce self-supporting films or biodegradable papers.
• This patent describes the possibility of having latex obtained from microorganisms which have the characteristics necessary for their use as binding agents for pigmentary compositions, and which have the advantage of leading to coated papers or biodegradable and recyclable coating films.
• the binding properties of the latexes described in this patent application are only borne by a only family of polyhydroxyalkanoates whose side chains contain from 1 to 12 carbon atoms.
• these latexes are present in the native state in the form of essentially amorphous wet granules, they have the disadvantage of being organized in a very crystalline state, in particular once dried and / or after deposition on a support. .
• this aptitude for crystallization of these latexes does not intend them to be correctly implemented in applications where it is essential on the one hand, to promote the coalescence of the particles of the emulsion, and on the other hand obtain dried films having adequate mechanical and optical properties.
• the filming of the aqueous polymer dispersions in fact requires that perfect interpenetration / fusion of the particles of the dispersed polymer be obtained after evaporation of the water (phenomenon known as “coalescence”).
• coating sauces, coating films or paints it is therefore essential to maintain the latexes in a non-crystalline state in order to promote said melting of the particles on the surface of the support and to obtain mechanical and optical properties similar to those usually obtained with non-biodegradable or difficult to recycle synthetic polymer latexes.
• biodegradable polymers can generally be in the form of latex
• US Pat. No. 6,024,784 actually only experimentally envisages the use of organic solutions of poly 3-hydroxyalacanoates (PHA) for the preparation of paints Solvent.
• PHA poly 3-hydroxyalacanoates
• Organic solvents of petroleum ether, diethyl ether or chloroform type, aromatic solvents of toluene or xylene type, or even aliphatic solvents are recommended to dissolve the PHA, before its use as a binder. This technical solution therefore does not meet the environmental requirements sought, because only formulations of solvent-based paints are offered.
• a film-forming composition containing an aqueous dispersion of at least one biodegradable polymer, preferably free from all volatile organic compounds, with high dry matter which may not understand that biodegradable ingredients and easily implemented for the preparation of aqueous film-forming compositions, whether pigmentary or adhesive such as coating sauces; aqueous pigment film-forming preparations, adhesives, or aqueous paints, without the need for heavy, difficult and complex steps.
• the Applicant Company has had the merit of reconciling all of these objectives, hitherto deemed difficult to reconcile, by proposing to use an aqueous dispersion of at least one biodegradable polymer, containing at least one stabilizing agent present in a sufficient but not excessive amount, to the manufacture of such film-forming compositions.
• the present invention thus relates to the use, for the preparation of an aqueous film-forming composition of a dry matter at least equal to 30%, of an aqueous dispersion composed of an organic phase dispersed in an aqueous dispersing phase, said dispersion containing, relative to its dry matter: - from 94 to 99.5% on dry basis of organic phase comprising at least one biodegradable polymer, and - from 0.5 to 6% of at least one stabilizing agent.
• the dispersion used for the preparation of an aqueous film-forming composition of a dry matter at least equal to 30% contains with respect to its dry matter: - from 95 to 99.5% on dry basis of organic phase comprising at least one biodegradable polymer, and - from 0.5 to 5% of at least one stabilizing agent.
• the present invention relates to the use of an aqueous dispersion as defined above for the preparation of an aqueous film-forming composition having a dry matter, at least equal to 35% by dry weight, preferably between 45 and 99.9% by dry weight, and more preferably still between 50 and 75% by dry weight.
• the aqueous dispersions of at least one biodegradable polymer of the state of the art generally have too high a viscosity. Therefore, at high dry matter, it is favored, in the case of aqueous pigment compositions, strong interactions between the pigments and the components of the aqueous dispersion. Strong interactions can then cause phase inversions which lead to breaking the homogeneity of the pigment composition while considerably increasing the viscosity. This increase in viscosity becomes so strong that it makes the pigment composition unsuitable for use in coating sauces, aqueous pigment film-forming preparations or in aqueous paints.
• a stabilizing agent in the aqueous dispersion constituting the film-forming composition was necessary, in an appropriate, sufficient amount, but not excessive so as not to harm good coalescence of the dispersed organic phase particles.
• stabilizing agents can be proteins, starches, polyvinyl alcohols, gums, celluloses and polyols, in native or modified form, taken alone or in combinations.
• stabilizing agents can also be polymeric emulsifiers such as for example crosslinked acrylic copolymers of high molecular weight comprising a hydrophobic co-monomer, and in particular a crosslinked copolymer of acrylic acid and alkyl methacrylates of 10 to 30 carbon atoms (such as PEMULEN ® sold by the company NOVEON).
• the stabilizing agents are preferably polyvinyl alcohols with a degree of hydrolysis of between 60 and 98%, preferably from 70 to 90%, gum arabic, xanthan gum, modified starches or celluloses, preferably esterified (methylated , carboxymethylated, acetylated or alkyl succinylated) or etherified (cationic or hydroxypropylenated).
• stabilizing agents must be present in the aqueous dispersion in a proportion of between 0.5 to 6% by dry weight, preferably between 1 to 5.5% by dry weight, and more preferably between 0.5 and 5%. and very preferably between 1.5 and 5% by dry weight of the dry matter of said aqueous dispersion. It is then possible to incorporate from 94 to 99.5%, preferably from 95 to 99%, of biodegradable polymer (s) in said aqueous dispersion, which allows an aqueous dispersion of a richness to be obtained. never before achieved for the preparation of the aqueous film-forming composition in accordance with the invention.
• the Applicant Company has in fact found that at stabilizing agent contents of less than 0.5%, the aqueous dispersion does not have sufficient stability to be incorporated as a binder in an aqueous film-forming composition with high dry matter. At contents greater than 5%, the excessively high content of stabilizing agents is detrimental to the coalescing properties necessary for the manufacture, for example, of coating sauces, aqueous pigment film-forming preparations, aqueous paints or aqueous adhesive compositions.
• the aqueous film-forming composition in accordance with the invention is also characterized in that, both in its content and in its use, it is preferably obtained by using an aqueous dispersion devoid of volatile organic solvents.
• the absence of volatile organic compounds in this aqueous film-forming composition results in a VOC content which does not exceed that of the ingredients of said aqueous film-forming composition, ie at most equal to 15,000 ppm, preferably at most 5,000 ppm, and more preferably still at most 1,000 ppm.
• the aqueous film-forming composition in accordance with the invention therefore does not have any of the drawbacks of the preparations of the prior art, and thus makes it possible to escape the problems of toxicity, additional costs, complexity of the stages implemented, the obligation to 'install leak prevention devices, explosion protection or recovery of volatile organic solvents and their inevitable impact on one environment.
• the Applicant company has found that the choice of the type of aqueous dispersion devoid of volatile organic solvents is not a limiting factor, which in itself is remarkable.
• Each of the known types of process for obtaining aqueous dispersions of at least one biodegradable polymer described above can therefore be suitable. Indeed, it is by the choice of a given stabilizing agent, in given proportions, that it is possible to incorporate all types of biodegradable polymer in said aqueous dispersion.
• the Applicant company only recommends the use of aqueous dispersions comprising from 0.5 to
• the applicant company recommends choosing more particularly two families of aqueous dispersions constituted by an organic phase dispersed in an aqueous dispersing phase devoid of volatile organic compounds for the preparation of the aqueous film-forming composition with high dry matter in accordance with the invention .
• the first family corresponds to the aqueous dispersions developed by the Applicant company, comprising in their organic phase: - at least one viscosity reducing agent having a solubility parameter of between 15 and 28 (J.cm-
• aqueous dispersions have a low viscosity even at high dry matter, so that they are particularly suitable for the preparation of pigment compositions with high dry matter according to
• the Applicant company recommends choosing the viscosity reducing agent from the group of esters of acids and alcohols, optionally ethoxylated, preferably mono-, di- or tri-esters of organic acids, carbonic acid. and phosphoric acid, sugars or polyols. It may also be chosen from the group of ethers optionally ethoxylated from sugars, from polyols (in particular from isosorbide), from glycol or from phenol, from ether-esters of glycols or from epoxidized triglyceride oils. It is desirable to choose it biodegradable or compostable and of food grade.
• the viscosity reducing agent also advantageously has a boiling point greater than 130 ° C., preferably greater than 150 ° C. and more preferably still greater than 200 ° C., which places it in the category of heavy solvents which are particularly well suited to their function.
• the Applicant company recommends in particular to choose the viscosity reducing agent from the group consisting of glycerol triacetate, isosorbide diacetate, isosorbide dibutylate, isosorbide di-isobutylate, isosorbide dioctanoate, dimethyl isosorbide, ethyl lactate, butyl lactate, tributyl citrate, triethyl citrate, bis (2 ethylhexyl) adipate, diisobutyladipate, dibutyl phthalate, propionic acid, glycerol tributyrate, glycerol triisobutyrate, ethylene glycol dibenzoate, diethylene glycol dibenzoate, propylene glycol dibenzoate, dipropylene glycol dibenzoate, tri ethylene glycol benzoate, dibutyl sebaçate, diisobutyl sebaçate, propylene carbonate, poly ethylene glyco
• the biodegradable polymer is non-crystallizable, and is chosen from the group consisting of biodegradable polymers of polylactates (or PLA), polymalates (or PMA), polyhydroxyalkanoates (or PHA), polycaprolactone (or PCL), polyesteramides (PEA) ), aliphatic copolyesters (PBSA) and aliphatic-co-terephatalate copolyesters (PBAT), celluloses or starches which are highly acetylated or made hydrophobic by the introduction of fixed fatty chains, taken alone or in combination, in the form of homopolymers, heteropolymers, whether linear, branched, crosslinked, dendritic or grafted.
• biodegradable polymers of polylactates (or PLA), polymalates (or PMA), polyhydroxyalkanoates (or PHA), polycaprolactone (or PCL), polyesteramides (PEA) ), aliphatic copolyesters (PBSA) and aliphatic
• the biodegradable polymers are heteropolymers, preferably di-, tri- or tetra-polymers whose monomers are diols, caprolactones or acids and hydroxy acids chosen from the group consisting of lactic D, lactic L , glycolic, tetramethylglycolic, malic, ⁇ propiolactic, butyric, valeric, phthalic, terephthalic, succinic, adipic, sebacic, hexanoic, octanoic, decanoic, dodecanoic, tetradecanoic, hexadecanoic and octadecanoic.
• the Applicant company recommends selecting at least two monomers to be polymerized so that the first is solid at room temperature, and the second more fluid at this temperature.
• aqueous dispersions are obtained which are well suited to the formation of films.
• the biodegradable polymers can be random, alternating, block or block heteropolymers.
• the Applicant Company has shown that the ability of polymers to crystallize strongly is not recommended for aqueous dispersions intended for the preparation of aqueous film-forming compositions. It is therefore advantageous to retain a biodegradable polymer present in said dispersions in non-crystallizable form, ie in amorphous form or in semi-crystalline form, and preferably in amorphous form.
• the Applicant company also recommends maintaining said polymer in amorphous or semi-crystalline form after its application and / or drying on a support.
• the “amorphous” form of the biodegradable polymer contains at most 25% of polymers in crystallized form.
• the “semi-crystalline” form contains at most 60% of polymers in crystallized form.
• a functionalized biodegradable polymer is chosen, preferably by a group of aldehyde, fluorinated, carboxylic acid, amino and alcohol type.
• amorphous biodegradable polymers or semi-crystalline type PHA offered especially by the company Procter & Gamble under the brand name NODAX ® and the PLA type of biodegradable polymers offered notably by GALACTIC company under the brand name GALASTIC ® L68, were particularly suitable. It is in particular use a mixture of NODAX ® PLA with amorphous or semi-crystalline and / or highly acetylated starches or rendered completely hydrophobic.
• the presence of a given stabilizing agent is necessary.
• an emulsifier group for the preparation of said aqueous dispersions, an emulsifier group is used, for example an emulsifier group such as one of those sold by the company EMULBITUME (Trégueux - France) comprising: - a turbomalaxer, - two sets for preparing the organic phase to be dispersed and the dispersing aqueous phase each comprising a heat-insulating tank, a positive displacement pump and a set of heat-insulated pipes.
• This type of device allows the preparation of aqueous dispersions at atmospheric pressure and at a flow rate of at least 100 l / h, by placing the organic phase to be dispersed in the molten state in simultaneous contact, comprising on the one hand the biodegradable polymer (s) with the viscosity reducing agent, and on the other hand the aqueous dispersing phase comprising the stabilizing agents.
• the second family of aqueous dispersions consisting of an organic phase dispersed in an aqueous dispersing phase devoid of volatile organic compounds which can be used for the preparation of aqueous film-forming compositions of high dry matter, is directly extracted and purified from microorganisms.
• the Applicant company has found that for the preparation of said aqueous film-forming composition in accordance with the invention, it is necessary to adjust the purification conditions of the native granules of biodegradable polymers, so that their content of stabilizing agents, in particular proteins, is between 1 and 5%, preferably between 1 and 4% by dry weight relative to the dry weight of polymers.
• the Applicant Company has in fact found that at levels of stabilizers, in particular proteins, of less than 1%, the aqueous dispersions of bacterial polymers generally did not have a sufficient level of stability to be incorporated as a binder of aqueous film-forming compositions high dry matter.
• the excessively high content of stabilizers, in particular proteins becomes detrimental to the coalescing properties necessary for the manufacture of coating sauces, aqueous pigment film-forming preparations and aqueous paints, or aqueous adhesive compositions .
• the protein content of native bacterial polymer granules can be adjusted by any method known per se to those skilled in the art, during the purification steps. The applicant company recommends using purification methods of the type using those of sodium hypochlorite, methods which make it possible to digest the biomass without degrading the polyhydroxyalkanoates, and leaving a quantity of proteins stabilizing the colloidal suspension sufficient for facilitate the coalescence of native granules.
• the dry matter of the aqueous dispersion used for the preparation of the aqueous film-forming compositions is between 25 and 70% by weight, preferably between 35 and 70% by weight, and more preferably still between 45 and 65% by weight. weight.
• An aqueous dispersion composed of an organic phase dispersed in an aqueous dispersing phase characterized in that it has a dry matter of between 25 and 70% by weight, preferably between 35 and 70% by weight, and more preferably still between 45 and 65% by weight and relative to its dry matter, from 95 to 99.5% on dry basis of organic phase comprising at least one biodegradable polymer, and from 0.5 to 5% of at least one agent stabilizer, appears particularly suitable for the preparation of aqueous film-forming composition in accordance with the invention.
• the preparation of the aqueous film-forming composition in accordance with the invention is carried out by mixing its constituents, by any method known per se by those skilled in the art, as will be exemplified below.
• the aqueous film-forming composition thus obtained is particularly well suited to the manufacture of aqueous pigment compositions such as coating sauces, aqueous pigment film-forming preparations or paints, or also aqueous adhesive compositions.
• the aqueous pigment composition according to the invention has a dry matter at least equal to 30% and contains: - as a binder, an aqueous dispersion of biodegradable polymer belonging to one of the families defined above, - at at least one adjuvant, - and at least one pigment.
• the aqueous adhesive composition according to the invention has a dry matter at least equal to 30% and contains: - as a primary binder, an aqueous dispersion of biodegradable polymer belonging to one of the families defined above, - as secondary binder, a polysaccharide chosen in particular from native and modified starches, native and modified celluloses, preferably soluble in water, - at least one adjuvant, - and optionally at least one pigment.
• the aqueous adhesive composition according to the invention may in particular be an adhesive for labeling to spiral mandrels, for corrugated paperboard, sack for, for wallpapers, carpet and rugs, for against-bonding, for nonwovens, for cigarettes, mural.
• aqueous adhesive composition can be easily diluted with water depending on its mode of application on the surface or the material to be coated or to be bonded.
• a first aqueous dispersion (Dispersion No. l) is prepared from polylactate GALASTIC ® L68, manufactured and marketed by the company GALACTIC having a molecular weight of 68,000 Da, a polydispersity index of 2.78, a temperature glass transition of 55 ° C, a complex viscosity of 2,380 Pa.s at 130 ° C and 34 Pa.s at 160 ° C, a crystallinity rate close to 0% and a lactic D content after hydrolysis of 12, 4%.
• the diéthylglycoldibenzoate commercially available from Velsicol under the trade name BENZOFLEX ® 2- 45, boiling point of 236 ° C.
• the stabilizing agent used is polyvinyl alcohol POVAL JP 18Y, having a degree of hydrolysis of 88 ⁇ 1%, a viscosity of 25 ⁇ 2 mPa.s, with a purity greater than 94% sold by the company TVP JAPAN VAM & Co. Ltd.
• the process for manufacturing the aqueous polylactate dispersion comprises the following steps: 1) preparation of the organic phase to be dispersed: In an electrically heated tank kept at
• aqueous pigment compositions according to the invention are prepared with mechanical agitation DISPERMAT at 5,000 rpm and for 2 min, by gradually adding, to 16 g of an aqueous pigment suspension of calcium carbonate, sold by the company OMYA under the name SETACARB ® brand, 75% dry matter, 8 g of demineralized water and 35 g of one or other of the DISPERSIONS n ° 1, 2 or 3 having the characteristics given in table I.
• These aqueous pigment compositions respectively obtained with dispersions 1, 2 and 3 are named CPl, CP2 and CP3. Their main characteristics are given in Table II below. Table II
• aqueous pigment compositions thus obtained are stable in the sense that no coagulation, flocculation or phase inversion is observed. These pigment compositions also have good film-forming properties and a viscosity of an acceptable level for use as aqueous pigment film-forming preparations.
• new aqueous dispersions are prepared from DISPERSION No. 2 (DISPERSIONS No. 5 to No. 9) by adding to this dispersion No. 2 by simple mixing, as additional stabilizing agents, increasing amounts a hydrogenated glucose syrup such as POLYSORB 70/12/12 ® marketed by the Applicant company.
• a content of stabilizing agents of between 0.5 and 5% on a dry basis of the DM of the aqueous dispersions makes it possible both: to obtain stable aqueous dispersions (absence of coagulation or solidification, even after several months), and having more good film-forming properties and good water-resistance properties, and preparing pigment compositions also having good film-forming properties while having rheological characteristics suitable for their use as aqueous pigment film-forming preparations.
• An aqueous pigment composition is prepared intended for a coating sauce formula of the TOP-LAYER / MONO-LAYER type (top coat, single coat) from DISPERSION n c 4 of Example 1 and compares it to a sauce formula.
• coating prepared from a synthetic aqueous dispersion as follows: 1) Formulation of a coating coating called TOP-LAYER / MONO-LAYER (top coat-single coat) from DISPERSION n ° 4 of l 'example 1 (SAUCE 1, according to the invention) Successively added with mechanical stirring
• the dry matter of the pigment composition is adjusted to 60% with demineralized water.
• the pH of this same pigment composition is adjusted to 9 with sodium hydroxide.
• the viscosity measured with the Brookfield viscometer is 620 mPa.s at 100 rpm - 30 ° C.
• the viscosity measured with the Hercules rheometer (model of the DV-10 type manufactured by Kaltec Scientific, Inc.) at a shear of 40,000 s "1 is 42 mPa.s. 2) Formulation of a coating sauce called Top-Layer
• the papers are then calendered using a laboratory calender of the RK 22 HU type manufactured by the company Ramisch & Co.
• the calendering step is a necessary step to give the coated papers a smooth and shiny appearance.
• the calendering conditions are 1 pass at 2.5 bars and at 120 ° C.
• the papers after being stored in a conditioned room (23 ° C / 50% RH) are then analyzed, the results of which are shown in Table V below:
• the papers coated with the coating sauce, in accordance with the invention, containing the DISPERSION No. 4 (SAUCE 1) give, compared to the coating sauce containing the synthetic aqueous dispersion (SAUCE 2), identical results in terms of smoothness , porosity, rigidity and better in terms of whiteness and opacity.
• EXAMPLE 3 The aqueous pigment composition CP1 as obtained in Example 1 is used as an adhesive aqueous pigment film-forming preparation, in comparison with a control adhesive formulation.
• Said adhesive formulation is prepared by mixing witness to 5000 rev / min for 2 min by: - 16 g of pigment suspension ® Setacarb OG 85 to 75% solids, available from OMYA, - 8 g of deionized water, - 35 g latex RHODOPASS a ® 013P as sold by the company Rhodia (MS 54%, pH of 4.5, viscosity 6000 mPa.s) and corresponding to a plasticized polyvinyl acetate with dibutyl adipate.
• This control adhesive formulation has a BROOKFIELD viscosity of 8500 mPa.s at 20 ° C.
• the bonding performance of the aqueous pigment composition CP1 of Example 1 and the control formulation are evaluated in a comparative manner according to a FIPAGO test measuring the development of the adhesiveness on a STROHLEIN device. The principle of this test consists in assessing the development over time of the tear resistance developed by the adhesive compositions tested between two papers, one being placed on a fixed support, the other fixed to an articulated arm. The two papers are of the same quality, of dimensions
• the adhesive pigment composition according to the invention although leading to a slower bonding than the control adhesive formulation, has good adhesive characteristics.
• * measured by the slot height in mm corresponding to the pair of ridges whose gap is still visible.
• DISPERSIONS # 1 and # 2 both completely replace the non-biodegradable synthetic binder resin REPOLEM ® 2423, in the formulation of matt or satin aqueous paints, without compromising their physical stability, nor their basic properties. It advantageously appears that the paints comprising DISPERSIONS No. 1 and No. 2 have, unlike control paints, a flow threshold favorable to their application on a support.
• Example 5 There is described an aqueous adhesive composition according to the invention from an aqueous dispersion free from organic solvents polylactate GALASTIC ® L 68.
• This aqueous dispersion is obtained according to the conditions described in Example 1 (Dispersion # 5 ) and contains: demineralized water: 40.86% polyvinyl alcohol POVAL JP 18Y: 1.07% xanthan: 0.07% polylactate GALASTIC ® L 68: 46.40% - dipropylene glycol dibenzoate: 5.80% methyl ester of vegetable oil: 5.80%
• This dispersion has a BROOKFIELD viscosity of 650 mPa.s for a dry matter of 56%.
• Usable aqueous adhesive composition was prepared as glue for cigarettes or gluing glue counter by making the dispersion 300 g of soluble starch in cold water marketed by the Applicant under the trade name DEXYLOSE ® 250 in 700 g of demineralized water. After 30 minutes of mechanical stirring at 1500 rpm, 300 g of the above aqueous dispersion are introduced. The pH is then adjusted to a value of 3 by adding sodium hydroxide solution. A homogeneous adhesive is thus obtained having a BROOKFIELD viscosity of 4200 mPa.s for a dry matter of 35.2%. Bonding tests carried out on FIPAGO material show that this highly biodegradable and repulpable glue has a very good ability to be used in laminating of papers, since there is a defibration of the paper after only 30 seconds.

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• Chemical & Material Sciences (AREA)
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• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
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• Chemical Kinetics & Catalysis (AREA)
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• 2004
  • 2004-05-10 FR FR0405038A patent/FR2862310B1/fr not_active Expired - Fee Related
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