Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/63—Block or graft polymers obtained by polymerising compounds having carbon-to-carbon double bonds on to polymers
  • C08G18/633—Block or graft polymers obtained by polymerising compounds having carbon-to-carbon double bonds on to polymers onto polymers of compounds having carbon-to-carbon double bonds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/63—Block or graft polymers obtained by polymerising compounds having carbon-to-carbon double bonds on to polymers
  • C08G18/637—Block or graft polymers obtained by polymerising compounds having carbon-to-carbon double bonds on to polymers characterised by the in situ polymerisation of the compounds having carbon-to-carbon double bonds in a reaction mixture of saturated polymers and isocyanates
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/63—Block or graft polymers obtained by polymerising compounds having carbon-to-carbon double bonds on to polymers
  • C08G18/638—Block or graft polymers obtained by polymerising compounds having carbon-to-carbon double bonds on to polymers characterised by the use of compounds having carbon-to-carbon double bonds other than styrene and/or olefinic nitriles

Definitions

• the invention relates to crosslinkable compositions. of the polyurethane acrylate type by ionizing radiation, for the finishing coating of metallic or metallized surfaces.
• the invention also relates to the application of the compositions crosslinkable by ionizing radiation, as a finishing coating, on metallic or metallized surfaces.
• metal or metallized surfaces intends to define all the metallic or non-metallic substrates, the latter having undergone a metallization treatment by known means of metallization, such as, in particular, vacuum metallization, sputtering (sputtering) or others.
• varnishes intended for the finishing coating of metallic or metallized surfaces have been the subject of numerous researches and even of industrial developments, these varnishes having to possess essential qualities of adhesion to the substrate, of high hardness and a excellent resistance to aqueous or alcoholic media.
• substrates to be treated are, for example, metallic objects or other materials, such as metallized polymers, which it is desirable to coat with a finishing layer, to provide them with a transparent coating, protecting them against attack by the environment. All these substrates, when they are poorly protected, are the site of chemical transformation actions which cause a loss of adhesion of the film, or of modification of appearance, especially when said substrates are exposed, even naturally, to humid atmospheres. , or even simply atmospheric.
• a first proposed route consists in placing between the metallic or metallized surface and the finishing varnish, an intermediate undercoat subsequently promoting the adhesion of the finishing varnish.
• This route considered to be relatively advantageous by the qualities which it provides to the varnish deposited on the surface to be treated, however has major drawbacks which make its industrial operation difficult. Indeed, this route requires the realization of two successive operations, one concerning the adhesion sublayer, its deposition and its formation by reaction of its compounds, the other relating to the deposition of the finishing varnish, therefore that said sub-layer is capable of receiving it.
• a second way proposed and exploited consists in incorporating within the finishing varnish, an adhesion promoter such as, for example, acrylic and methacrylated derivatives of an acidic nature, which should promote the adhesion of the film of finish on the metallic or metallized surface to be treated.
• an adhesion promoter such as, for example, acrylic and methacrylated derivatives of an acidic nature, which should promote the adhesion of the film of finish on the metallic or metallized surface to be treated.
• compositions of finishing varnish are described in the specialized literature.
• German patent 2,601,408 describes compositions for varnishes intended for the manufacture of printing inks, the compositions resulting from the mixture:
• - a hydroxylated ethylenic compound originating from the condensation reaction between an epoxy resin and an unsaturated carboxylic acid
• - a polyisocyanate compound obtained by addition reaction between an aromatic polyisocyanate (Toluylene diisocyanate TDI), and an unsaturated carboxylic acid .
• At least one acrylic monomer and one photoinitiator are added to the adduct obtained by ionic reaction of these two compounds, the radical reaction being carried out by ultraviolet irradiation.
• Another patent, Japanese Patent JP 59-080473 describes compositions for varnishes intended for the protection of electrical insulators. These compositions are obtained (a) by the addition reaction between a polyol and an aromatic polyisocyanate, leading to a compound with free -NCO function and (b) by the reaction of the addition compound with -NCO functions originating from (a ) with various hydroxylated acrylic compounds.
• the reaction product obtained can be polymerized under ultraviolet irradiation in the presence of a photoinitiator.
• a first object of the invention aims to obtain crosslinkable compositions for the finishing coating of metallic or metallized surfaces requiring neither the use of a bonding prelayer, nor the introduction into the compositions of finishing varnishes, of a large amount of adhesion promoter.
• Another object of the invention is to obtain crosslinkable compositions for the finish coating of metallic or metallized surfaces having, after crosslinking, excellent adhesion characteristics on the metallic or metallized surface, hardness and resistance to l water and / or alcohol by immersion.
• another subject of the invention aims at the new application of finishing compositions, crosslinkable by ionizing radiation to the protection of metallic and / or metallized surfaces of substrates to be protected.
• compositions of the polyurethane acrylate type, crosslinkable by ionizing radiation, for the finishing coating of metallic or metallized surfaces, obtained by the mixture of two liquid and / or pasty phases, one (A) containing the polyols , and the other (B) polyisocyanates, are characterized in that the two phases mainly comprise dry matter:
• compositions of the polyurethane acrylate type obtained by the polymerization reaction between the hydroxylated functions and the isocyanates
• the invention is distinguished by the fact that the compositions of the polyurethane acrylate type developed contain among the components at least a hydroxylated vinyl polymer, at least one at least difunctional acrylic monomer, and at least one polyisocyanate.
• the crosslinkable compositions of the polyurethane acrylate type for the finishing coating of metallic and / or metallized surfaces according to the invention have the qualities sought and hitherto not acquired, which are those of adhesion to the substrate, hardness and resistance to aqueous or alcoholic media.
• the crosslinkable compositions according to the invention comprise at least one hydroxylated vinyl homopolymer and / or copolymer (component A1) taking advantage of their advantageous hydrophobic properties.
• These hydroxylated vinyl homopolymers and / or copolymers are chosen from those known having an average molecular weight of between 4000 and 35000 and preferably between 5000 and 30000.
• hydroxylated polyvinyl halides such as hydroxylated polyvinyl chloride
• vinyl esters such as polyvinyl acetate
• hydroxylated vinyl copolymers such as acetochloride.
• hydroxylated vinyl polymers and / or copolymers are for example known under the trade names such as UCAR VAGH, UCAR VAGF, UCAR VAGD, UCAR VROH, UCAR VYES, from SOCIETE UNION CARBIDE, or also VINNOL E15 / 40 A, E15 / 48 A, E20 / 55 A, E22 / 40 A, E22 / 48 A, from WACKER CHEMIE or HOSTAFLEX CM 158, HOSTAFLEX VCM 1550, from the company HOECHST.
• the acrylic monomer having at least two ethylenic functions (component A2) is chosen from di or trifunctional acrylates having the property of being crosslinked according to any of the methods known to those skilled in the art, such as for example , chemical crosslinking, or crosslinking by ionizing radiation, ensuring the "in situ" polymerization of said monomer.
• acrylic monomers are, for example, 1,6 hexane diol diacrylate, tripropylene glycol diacrylate, 1,3 butane diol diacrylate, trimethylol propanetriacrylate, pentaerythritol triacrylate, triethylene glycol diacrylate, glyceryl propoxy triacrylate ethyl trimethylol triacrylate, dipenta erythrytol penta acrylate, polyethylene glycol 200 or 400 diacrylate.
• the acrylic derivative having an acidic nature (constituent A3) is chosen from the group consisting of acrylic and methacrylated derivatives of acidic nature.
• constituents are known, for example, under trade names such as EBECRYL 169 or EBECRYL 170 PA, from SOCIETE U. C.B.
• the acrylic derivative having an acidic nature is introduced into the photocrosslinkable compositions of the polyurethane acrylate type according to the invention, at very low doses, ranging from 0.5% to 3% by weight relative to in total of dry matter of said compositions, the doses being from 3% to 10% in the known art.
• At least one crosslinking initiating agent (constituent A4) can also be introduced into the compositions according to the invention to promote crosslinking thereof.
• This crosslinking initiating agent can be chosen from those known, such as, for example, hydroxy 1 - cyclohexyl phenylketone, 2 hydroxy - 2 methyl 1 - phenyl propane 1 one, (4 isopropylphenyl) - 2 - hydroxy 2 methyl propane 1 - one, the derivatives of Thioxanthone, acetophenone, benzophenone, or benzyl dimethyl ketal.
• photoinitiators are known, for example, under the trade names of: IRGACURE 184 (CIBA GEIGY), DAROCUR 1173 or DAROCUR 1116 (MERCK), LUCIRIN BDK (BASF).
• the polyisocyanates used according to the invention are compounds of the aliphatic and / or aromatic type, alone or mixed, such as for example, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), toluene diisocyanate (TDI), diphenyl methane diisocyanate 4 - 4 'and its counterparts (MDI), naphthalene diisocyanate 1 - 5 (NDI), or still appearing as prepolymers obtained by the combination of isocyanates between them or with reactive compounds.
• HDI hexamethylene diisocyanate
• IPDI isophorone diisocyanate
• TDI toluene diisocyanate
• MDI diphenyl methane diisocyanate 4 - 4 'and its counterparts
• NDI naphthalene diisocyanate 1 - 5
• compositions according to the invention can also be introduced into the compositions according to the invention.
• these various possible adjuvants belong to the groups of dispersing agents, dyes, biocidal agents, anti-scratching agents or tensioning agents or the like.
• phases (A) and (B) of the compositions which can be crosslinked according to the invention by ionizing radiation appear in the form of solutions and / or dispersions in suitable organic liquids, compatible with each other and with the various constituents involved in the formation of the finishing coating of metallic and / or metallized surfaces.
• Such organic liquids are for example: ethyl acetate, methyl isobutyl ketone, toluene, xylene, ethyl glycol acetate, methoxy propyl acetate, diacetone alcohol, cyclohexanone, used alone or as a mixture.
• the coating compositions according to the invention obtained by mixing the two phases (A) and (B) in solution and / or dispersion, consist of quantities expressed as percent by weight of the various main constituent substances, it being understood that both phase (A) and (B) may also contain other specific agents well known in the field of surface finishing coatings metallic and / or metallized.
• compositions according to the invention comprise, expressed in percent by weight of dry matter relative to the total mass of said material:
• (A1) from 10% to 60% and preferably from 15% to 50% by weight of at least one vinyl hydroxylated polymer and / or copolymer.
• (A2) from 15% to 65% and preferably from 20% to 45% by weight of at least one acrylic monomer having at least two ethylene functions.
• (A3) from 0.5 to 3% and preferably from 1.0% to 2.8% by weight of at least one acrylic derivative having an acidic character.
• (A4) from 3% to 8% and preferably from 4% to 8% by weight of at least one crosslinking initiating agent.
• (B1) from 10 to 30% and preferably from 10% to 25% by weight of at least one polyisocyanate.
• the mixing of the two phases, both of which are dispersed and / or dissolved in at least one suitable organic liquid, is desirably carried out by a person skilled in the art at the time when the coating compositions are used, to coat the metallic or metallized substrates to be protected.
• the mixing can be carried out in a time interval preceding its use which can reach even up to 10 days.
• phases (A) and (B) are prepared dissolved and / or dispersed in the appropriate organic liquid and the viscosity of said mixture is adjusted, by introducing additional amounts of the organic liquid.
• the coating compositions according to the invention can be applied to the substrate according to any of the known methods such as, for example, the methods of compressed air spraying, spraying by electrostatic field, hot spraying or airless spraying.
• the coating compositions according to the invention are crosslinked according to methods known to those skilled in the art, which are chemical crosslinking, and crosslinking by ionizing radiation ensuring the elimination of the residual monomers by grafting and / or polymerization, and the possible formation of free radicals, the presence of which promotes the creation of internal defeats and granted to said compositions the desired characteristics.
• Sources usable for such treatment of ionizing radiation consist of radioactive isotopes emitting gamma radiation such as, for example, Co 60 and Cs 137, in X-ray generators, or in electron accelerators generating beta radiation , and UV sources
• the irradiation treatment of the compositions according to the invention can be carried out in air, in vacuum, or in suitable gas atmospheres, according to methods known and practiced by those skilled in the art.
• compositions according to the invention are particularly remarkable because of the exceptional qualities which they develop in comparison with the compositions of the prior art.
• an excellent adhesion to metallic and / or metallized surfaces can be mentioned more particularly, in the absence of an adhesion sublayer and their insensitivity to any humid and / or alcoholic atmosphere.
• the pencil hardness of a film is determined using pencils (with graphite lead) of increasing hardness (ranging from 6 B to B, HB to F and from H to 9 H). According to the test, the pencil hardness designates that of the pencils which leaves a trace of writing on the film, while the next in gradation of hardness penetrates the film by scratching it.
• This test is carried out using a device allowing the pencil to move slowly over the film, at an angle of 45 degrees and a load of 750 g.
• PERSOZ hardness test This test is described in French standard NFT 30016. It consists in measuring the damping time of the pendulum ostillations resting on the film to be checked by two steel balls.
• Water resistance test This test consists in immersing, for 24 hours, the film of the composition tested in water maintained at 40 degrees C. At the end of this immersion, the film must neither peel off nor whiten .
• This test consists in evaluating the abrasion resistance (measurement of the weight loss) of a film, of the composition to be checked, applied to a disc (made of aluminum), a diameter of 100 mm.
• compositions 1 to 8 were prepared by mixing the components necessary for one and the other phase in qualitative and quantitative conformity with the invention.
• the amounts of each component are expressed in percent by weight of dry matter relative to the total mass of each phase, and in percent by weight of dry matter relative to the total mass of dry matter present in the cumulative phases ( A) and (B).
• compositions that is to say the components and the solvents 1 to 8 have been combined in Table I below.
• IRGACURE 184 marketed by CIBA GEIGY
• compositions were applied to metallic or metallized surfaces, the application being carried out by spraying, using a pneumatic gun and in such a way that the deposited monolayer has, after hardening, approximately
• compositions according to the invention have undergone tests of adhesion, hardness and resistance to water and alcohol such as previously described.
• Example 9 illustrates the case of a two-layer protection according to the prior art, comprising an intermediate sublayer between the metallic or metallized surface and the finishing varnish, this sublayer having the property of promoting the adhesion of the latter.
• Example 10 illustrates the case of a monolayer protection according to the prior art, comprising a large amount of adhesion promoter, much greater than in the case of the invention.
• compositions were deposited on metallic or metallized surfaces, in accordance with the application protocol practiced in Examples 1 to 8, it being understood that the composition of Example 9 was deposited according to two successive operations, one concerning the adhesion undercoat, the other the topcoat.
• compositions of the prior art After pre-drying and crosslinking under ultraviolet radiation, the compositions of the prior art have undergone the same tests as those carried out in the case of the compositions according to the invention.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Paints Or Removers (AREA)
• Polyurethanes Or Polyureas (AREA)
• Macromonomer-Based Addition Polymer (AREA)

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Publications (1)

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Citations (3)

• 1990
  • 1990-02-01 FR FR9001385A patent/FR2657613B1/fr not_active Expired - Lifetime
• 1991
  • 1991-01-29 PT PT9659591A patent/PT96595A/pt not_active Application Discontinuation
  • 1991-01-29 WO PCT/FR1991/000050 patent/WO1991011479A1/fr not_active Application Discontinuation
  • 1991-01-29 EP EP19910903308 patent/EP0466880A1/fr not_active Withdrawn
  • 1991-01-31 IE IE032791A patent/IE910327A1/en unknown

Patent Citations (3)

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