Patent Application
20220153913
The present invention relates to a composition based on a methacrylate monomer.
The invention also relates to the use of said composition in the repair and/or the semistructural or structural adhesive bonding of materials in the transportation, marine, assembly or construction field.
Acrylic compositions are known reactive systems which crosslink by radical polymerization. They are used as adhesives, mastics and coatings. Radical polymerization is typically initiated by a redox system which, by means of an oxidation-reduction reaction, results in the production of radicals.
Most acrylic systems are two-component systems. The first component conventionally contains the reducing agent and the reactive monomers, and the second component contains the oxidizing agent. Once the two components have been mixed, the reducing agent induces cleavage of the 0-0 bond of the organic peroxide for example, and initiates polymerization.
In certain fields, such as the transportation field or even the construction field, the adhesive bondings can be subjected to high temperatures. This is for example the case for adhesive bondings close to the engine in the automobile, or even adhesives close to the windshield or windows and subjected to high temperatures due to solar radiation. It is therefore important that the adhesive bondings have a high resistance to these high temperatures, and that they maintain a good level of cohesion.
There is therefore a need for new acrylic compositions exhibiting high heat resistance.
There is a need for new acrylic compositions which exhibit high heat resistance while at the same time having good adhesion properties.
In the present application, unless otherwise indicated:
Composition
The present invention also relates to a two-component composition comprising:
said polyurethane P being obtained by a method comprising:
Polyurethane P
Polyisocyanate(s)
The polyisocyanate(s) which can be used can be added sequentially or reacted in the form of a mixture.
The polyisocyanate(s) can be chosen from diisocyanates or triisocyanates.
The polyisocyanate(s) can be monomer(s), oligomer(s) or polymer(s).
According to one embodiment, the polyisocyanate(s) are diisocyanate(s), preferably chosen from the group consisting of isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), heptane diisocyanate, octane diisocyanate, nonane diisocyanate, decane diisocyanate, undecane diisocyanate, dodecane diisocyanate, 2,4′-methylenebis(cyclohexyl isocyanate) (2,4′-H6MDI), 4,4′-methylenebis(cyclohexyl isocyanate) (4,4′-H6MDI), norbornane diisocyanate, norbornene diisocyanate, 1,4-cyclohexane diisocyanate (CHDI), methylcyclohexane diisocyanate, ethylcyclohexane diisocyanate, propylcyclohexane diisocyanate, methyldiethylcyclohexane diisocyanate, cyclohexanedimethylene diisocyanate, 1,5-diisocyanato-2-methylpentane (MPDI), 1,6-diisocyanato-2,4,4-trimethylhexane, 1,6-diisocyanato-2,2,4-trimethylhexane (TMDI), 4-isocyanatomethyl-1,8-octane diisocyanate (TIN), 2,5-bis(isocyanatomethyl)bicyclo[2.2.1]heptane (2,5-NBDI), 2,6-bis(isocyanatomethyl)bicyclo[2.2.1]heptane (2,6-NBDI), bis(isocyanatomethyl)cyclohexane (H6-XDI) (in particular 1,3-bis(isocyanatomethyl)cyclohexane (1,3-H6-XDI)), xylylene diisocyanate (XDI) (in particular m-xylylene diisocyanate (m-XDI)), toluene diisocyanate (in particular toluene-2,4-diisocyanate (2,4-TDI) and/or toluene-2,6-diisocyanate (2,6-TDI)), diphenylmethane diisocyanate (in particular diphenylmethane-4,4′-diisocyanate (4,4′-MDI) and/or diphenylmethane-2,4′-diisocyanate (2,4′-MDI)), tetramethylxylylene diisocyanate (TMXDI) (in particular tetramethyl-m-xylylene diisocyanate), an HDI allophanate having, for example, the following formula (Y):
wherein p is an integer ranging from 1 to 2, q is an integer ranging from 0 to 9 and preferably from 2 to 5, Rc represents a saturated or unsaturated, cyclic or acyclic, linear or branched, hydrocarbon-based chain comprising from 1 to 20 carbon atoms, preferably from 6 to 14 carbon atoms, and Rd represents a linear or branched divalent alkylene group having from 2 to 4 carbon atoms, and preferably a divalent propylene group;
and mixtures thereof.
Preferably, the allophanate of abovementioned formula (Y) is such that p, q, Rc and Rd are chosen such that the above HDI allophanate derivative comprises a content of isocyanate NCO groups ranging from 12% to 14% by weight, relative to the weight of said derivative.
According to one embodiment, the polyisocyanate(s) which can be used are triisocyanate(s), preferably chosen from isocyanurates, biurets, and adducts of diisocyanates and of triols.
In particular, the isocyanurate(s) can be used in the form of a technical mixture of (poly)isocyanurate(s) with a purity of greater than or equal to 70% by weight of isocyanurate(s).
The diisocyanate isocyanurate(s) which can be used according to the invention can correspond to the following general formula (W):
wherein:
R5 represents a linear or branched, cyclic, aliphatic, arylaliphatic or aromatic alkylene group comprising from 4 to 9 carbon atoms,
with the proviso that the NCO groups are not connected by a covalent bond to a carbon atom forming part of an aromatic hydrocarbon-based ring, such as a phenyl group.
As examples of diisocyanate trimers that may be used according to the invention, mention may be made of:
Mention may be made, as examples of adducts of diisocyanates and of triols which can be used according to the invention, of the adduct of meta-xylylene diisocyanate and of trimethylolpropane, as represented below. This adduct is sold, for example, by Mitsui Chemicals, Inc. under the name Takenate® D-110N.
Preferably, the polyisocyanate(s) is (are) chosen from diisocyanates, preferentially from toluene diisocyanate (in particular the 2,4-TDI isomer, the 2,6-TDI isomer or mixtures thereof), diphenylmethane-4,4′-diisocyanate, diphenylmethane-2,4′-diisocyanate, meta-xylylene diisocyanate (m-XDI), isophorone diisocyanate (IPDI), and mixtures thereof.
Even more preferably, the polyisocyanate is chosen from polyisocyanates based on diphenylmethane diisocyanate (MDI), and in particular from monomeric and polymeric polyisocyanates.
The diphenylmethane diisocyanate can be provided in the form of a single isomer, for example chosen from 2,4′-MDI and 4,4′-MDI, or in the form of a mixture of isomers, for example 2,4′-MDI and 4,4′-MDI. Preferably, the diphenylmethane diisocyanate is provided in the form of a mixture of isomers comprising more than 50% by weight of the 4,4′-MDI isomer and less than 50% by weight of the 2,4′-MDI isomer, the percentages being relative to the total weight of the diphenylmethane diisocyanate.
Usable polyisocyanate(s) is (are) typically commercially available. Mention may be made, by way of example, of Scuranate® TX sold by Vencorex, corresponding to a 2,4-TDI with a purity of the order of 95%, Scuranate® T100 sold by Vencorex, corresponding to a 2,4-TDI with a purity of greater than 99% by weight, Desmodur® I sold by Covestro, corresponding to an IPDI, or also Desmodur® N3300 sold by Covestro, corresponding to an HDI isocyanurate, Takenate™ 500 sold by Mitsui Chemicals, corresponding to an m-XDI, Takenate™ 600 sold by Mitsui Chemicals, corresponding to an m-H6XDI, Vestanat® H12MDI sold by Evonik, corresponding to an H12MDI, or of Suprasec 2004 sold by Huntsman (mixture of approximately 70% by weight of 4,4′-MDI monomer and of 30% by weight of 2,4′-MDI monomer, having a percentage of NCO of 32.8%).
Preferably, the polyisocyanate is chosen from:
Polyol(s)
The polyol(s) can be chosen from polyester polyols, polyether polyols, polyene polyols, polycarbonate polyols, poly(ether-carbonate) polyols and mixtures thereof.
The polyol(s) that can be used can be chosen from aromatic polyols, aliphatic polyols, arylaliphatic polyols and the mixtures of these compounds.
The polyol(s) which can be used can be chosen from that (those) having a number-average molecular weight (Mn) ranging from 200 g/mol to 20 000 g/mol, preferably from 400 g/mol to 18 000 g/mol.
The number-average molecular weight of the polyols can be calculated from the hydroxyl number (OHN), expressed in mg KOH/g, and from the functionality of the polyol or determined by methods well known to those skilled in the art, for example by size exclusion chromatography (or SEC) with PEG (polyethylene glycol) standard.
Preferably, the polyols have a hydroxyl functionality ranging from 2 to 6. In the context of the invention, and unless otherwise mentioned, the hydroxyl functionality of a polyol is the mean number of hydroxyl functions per mole of polyol.
According to the invention, the polyester polyol(s) can have a number-average molecular weight ranging from 1000 g/mol to 10 000 g/mol, preferably from 2000 g/mol to 6000 g/mol.
Among the polyester polyols, examples that may be mentioned include:
The abovementioned polyester polyols can be prepared conventionally and are for the most part commercially available.
Mention may be made, among polyester polyols, for example, of the following products with a hydroxyl functionality equal to 2:
According to the invention, the polyether polyol(s) may have a number-average molecular weight ranging from 200 to 20 000 g/mol, preferably from 300 to 12 000 g/mol and preferentially from 400 to 4000 g/mol.
The polyether polyol(s) that may be used according to the invention is (are) preferably chosen from polyoxyalkylene polyols, the linear or branched alkylene portion of which comprises from 1 to 4 carbon atoms, more preferentially from 2 to 3 carbon atoms.
More preferentially, the polyether polyol(s) that may be used according to the invention is (are) preferably chosen from polyoxyalkylene diols or polyoxyalkylene triols, the linear or branched alkylene portion of which comprises from 1 to 4 carbon atoms, more preferentially from 2 to 3 carbon atoms.
As examples of polyoxyalkylene diols or triols that may be used according to the invention, mention may be made of:
The abovementioned polyether polyols may be prepared conventionally and are widely available commercially. They can be obtained by polymerization of the corresponding alkylene oxide in the presence of a basic catalyst (for example potassium hydroxide) or of a catalyst based on a double metal/cyanide complex.
Mention may be made, as examples of polyether diol, of:
Mention may be made, as examples of polyether triol, of the polyoxypropylene triol sold under the name Voranol® CP 450 by Dow with a number-average molecular weight (Mn) in the vicinity of 450 g/mol and the hydroxyl number of which ranges from 370 to 396 mg KOH/g, or the polyoxypropylene triol sold under the name Voranol® CP3355 by Dow with a number-average molecular weight in the vicinity of 3554 g/mol, or Acclaim® 6300, which is a trifunctional PPG with a number-average molecular weight of approximately 5948 g/mol and with a hydroxyl number NOH equal to 28.3 mg KOH/g.
The polyene polyol(s) which can be used according to the invention can preferably be chosen from polyenes comprising hydroxyl end groups, and their corresponding hydrogenated or epoxidized derivatives.
Preferably, the polyene polyol(s) which can be used according to the invention is (are) chosen from polybutadienes including hydroxyl end groups, which are optionally hydrogenated or epoxidized. Preferentially, the polyene polyol(s) which can be used according to the invention is (are) chosen from butadiene homopolymers and copolymers comprising hydroxyl end groups, which are optionally hydrogenated or epoxidized.
In the context of the invention, and unless otherwise mentioned, the term “hydroxyl end groups” of a polyene polyol is understood to mean the hydroxyl groups located at the ends of the main chain of the polyene polyol.
The abovementioned hydrogenated derivatives can be obtained by complete or partial hydrogenation of the double bonds of a polydiene comprising hydroxyl end groups, and are thus saturated or unsaturated.
The abovementioned epoxidized derivatives can be obtained by chemoselective epoxidation of the double bonds of the main chain of a polyene comprising hydroxyl end groups, and thus comprise at least one epoxy group in their main chain.
Mention may be made, as examples of polyene polyols, of saturated or unsaturated butadiene homopolymers comprising hydroxyl end groups, which are optionally epoxidized, such as, for example, those sold under the name Poly BD® or Krasol® by Cray Valley, and also saturated or unsaturated isoprene homopolymers, comprising hydroxyl end groups, such as for example those sold under the name Poly IP™ or EPOL™ sold by Idemitsu Kosan.
The polycarbonate polyols may be chosen from polycarbonate diols or triols, in particular with a number-average molecular weight (Mn) ranging from 300 to 12 000 g/mol.
Examples of polycarbonate diols that may be mentioned include:
Monomer(s) M
The (meth)acrylate monomer M can be chosen from those having the following formula (I):
[Chem 9]
CH2═C(R6)—C(═O)—O—R7—OH (I)
wherein:
Preferably, the monomer M has one of the following formulae:
[Chem 10]
CH2═C(R6)—C(═O)—O—R7—OH (I-1)
wherein:
[Chem 11]
CH2═C(R6)—C(═O)—O—R6—O—[C(═O)—CH2)w—O]s—H (I-2)
wherein:
[Chem 12]
CH2═C(R6)—C(═O)—O—[R9—O]t—H (I-3)
wherein:
Among the monomers of formula (I-1), mention may be made, for example, of 2-hydroxyethyl methacrylate (HEMA), 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, 2-hydroxybutyl methacrylate, 2-hydroxyethyl acrylate (HEA), 2-hydroxypropyl acrylate (HPA), 4-hydroxybutyl acrylate (4-HBA) (for example available from Sartomer, Cognis or BASF).
Preferably, the monomer M is 2-hydroxyethyl methacrylate (HEMA):
[Chem 13]
CH2=)—C(═O)—O—CH2—CH2—OH
Step E1)
The polyaddition reaction E1) can be carried out at a temperature preferably of less than 95° C. and/or under preferably anhydrous conditions.
The polyaddition reaction can be carried out in the presence or absence of at least one catalyst.
The reaction catalyst(s) which can be used during the polyaddition reaction can be any catalyst known to those skilled in the art for catalyzing the formation of polyurethane by reaction of at least one polyisocyanate with at least one polyol.
An amount ranging up to 0.3% by weight of catalyst(s), relative to the weight of the reaction medium of the polyaddition step, can be used.
The polyaddition reaction E1) can be carried out in the presence or absence of at least one solvent. The solvent can be chosen from solvents which do not react with the reactive functions of the ingredients used in step E1). It can, for example, be methyl methacrylate, toluene, ethyl acetate, xylene and mixtures thereof.
Step E1) is preferably carried out in amounts of reactants such that the NCO/OH molar ratio (r1) ranges from 1.5 to 5, preferably from 1.5 to 2.5.
In the context of the invention, and unless otherwise mentioned, (r1) is the NCO/OH molar ratio corresponding to the molar ratio of the number of isocyanate (NCO) groups to the number of hydroxyl (OH) groups carried by respectively all of the polyisocyanate(s) and all of the alcohol(s) present in the reaction medium of step E1) (polyol(s)).
The polyurethane obtained in step E1) advantageously comprises two NCO end groups, said groups being present at the ends of the main chain.
Step E2)
Step E2) can be carried out at a temperature preferably of less than 80° C., preferentially less than or equal to 60° C., and/or under preferably anhydrous conditions.
Step E2) can be carried out in the presence or absence of at least one catalyst. It can be the same catalyst as that used in step E1).
Step E2) can be carried out in the presence or absence of at least one solvent. The solvent can be chosen from solvents which do not react with the reactive functions of the ingredients used in step E2). It can, for example, be methyl methacrylate, toluene, ethyl acetate, xylene and mixtures thereof.
Preferably, step E2) is carried out by addition of the monomer(s) M to the reaction medium of step E1), without isolation of the product formed in step E1).
Step E2) is preferably carried out in amounts of reactants such that the OH/NCO molar ratio (r2) is less than or equal to 1, preferentially ranges from 0.90 to 1.0 and more preferentially still ranges from 0.95 to 1.00.
In the context of the invention, and unless otherwise mentioned, (r2) is the OH/NCO molar ratio corresponding to the molar ratio of the number of hydroxyl (OH) groups to the number of isocyanate (NCO) groups carried respectively by all of the alcohol(s) and of the isocyanate(s) (as regards in particular the polyurethane having NCO endings and optionally the polyisocyanate(s) which have not reacted on conclusion of step E1)) present in the reaction medium of step E2).
At the outcome of step E2, the polyurethane P can be in solution in a solvent such as, for example, methyl methacrylate. The polyurethane content in the solution can range from 40% to 80% by weight, preferably from 50% to 70% by weight.
The polyurethane P preferably has a number-average molecular weight (Mn) greater than or equal to 2000, preferably greater than or equal to 5000 g/mol, preferably greater than or equal to 7000 g/mol, better still greater than or equal to 10 000 g/mol. The Mn of the polyurethane is measured by GPC with comparison with a polystyrene reference.
The polyurethane P preferably has at least two (meth)acrylate functions in the end position of the main chain.
(Meth)Acrylate Monomers
The (meth)acrylate monomers in composition A and in composition B may be identical or different.
The (meth)acrylate monomers can comprise one (monofunctional) or more (polyfunctional) (meth)acrylate functions.
The (meth)acrylate monomer(s) can be chosen from the group consisting of:
[Chem 14]
CH2═C(R10)—COOR11 (II)
wherein:
According to one embodiment, the (meth)acrylate monomer is chosen from methyl (meth)acrylate, ethyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, 2-tert-butylheptyl (meth)acrylate, octyl (meth)acrylate, 3-isopropylheptyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, 5-methylundecyl (meth)acrylate, dodecyl (meth)acrylate, 2-methyldodecyl (meth)acrylate, tridecyl (meth)acrylate, 5-methyltridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, 2-methylhexadecyl (meth)acrylate, heptadecyl (meth)acrylate, 5-isopropylheptadecyl (meth)acrylate, 4-tert-butyloctadecyl (meth)acrylate, 5-ethyloctadecyl (meth)acrylate, 3-isopropyloctadecyl (meth)acrylate, octadecyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate, 3-vinylcyclohexyl (meth)acrylate, bornyl (metha)crylate, 2,4,5-tri-t-butyl-3-vinylcyclohexyl (meth)acrylate, 2,3,4,5-tetra-t-butylcyclohexyl (meth)acrylate; benzyl (meth)acrylate, phenyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, and mixtures thereof.
Preferably, the (meth)acrylate monomer is a methacrylate.
Preferably, the (meth)acrylate monomer is methyl methacrylate.
Composition A may comprise a (meth)acrylate monomer content ranging from 20% to 80%, preferably from 40% to 70%, advantageously from 50% to 65% by weight relative to the total weight of part A.
The content of polyurethane P in composition A is preferably between 6% and 20% by weight, preferably between 6% and 15% by weight.
In one particular embodiment, the content of polyurethane P in composition A is from 6% to 10% by weight, preferably from 6% to 9% by weight, preferably from 6% to 8% by weight, and more preferably from 6% to 7% by weight relative to the total weight of composition A. These proportions are particularly preferred in that they make it possible to obtain compositions A having improved heat resistance, while at the same time having good adhesion properties.
The reducing agent can be chosen from tertiary amines, sodium metabisulfite, sodium bisulfite, transition metals, azo compounds, alpha-aminosulfones, and mixtures thereof.
Among the azo compounds, mention may for example be made of azoisobutyric acid.
Among the alpha-sulfones, mention may for example be made of bis(tolylsulfonymethyl)benzylamine.
Among the tertiary amines, mention may for example be made of diisopropanol-p-toluidine (DIIPT); dimethyl-p-toluidine; dipropoxy-p-toluidine; dimethylaniline; N,N-dimethylaminomethylphenol; N,N-diisopropanol-p-chloroaniline; N,N-diisopropanol-p-bromoaniline; N,N-diisopropanol-p-bromo-m-methylaniline; N,N-dimethyl-p-chloroaniline; N,N-dimethyl-p-bromoaniline; N,N-diethyl-p-chloroaniline; N,N-diethyl-p-bromoaniline; and mixtures thereof.
Preferably, composition A comprises at least one tertiary amine.
Composition A may comprise a content of reducing agent ranging from 0.5% to 5%, preferably from 1% to 3%, by weight relative to the total weight of composition A.
The oxidizing agent can be chosen from peroxides, organic salts of transition metals, compounds containing a labile chlorine, and mixtures thereof.
The peroxide can be chosen from organic peroxides, inorganic peroxides and mixtures thereof.
Mention may be made, among the inorganic peroxides, of peroxydisulfuric acid and its salts, such as ammonium peroxodisulfate, sodium peroxodisulfate and potassium peroxodisulfate.
Mention may be made, among the organic peroxides, of cumene hydroperoxide, para-menthane hydroperoxide, tert-butyl peroxyisobutyrate, tert-butyl peroxybenzoate, tert-butyl peroxyneodecanoate, tert-amyl peroxypivalate, acetyl peroxide, benzoyl peroxide, dibenzoyl peroxide, 1,3-bis(t-butylperoxyisopropyl)benzene, diacetyl peroxide, t-butylcumyl peroxide, tert-butyl peroxyacetate, cumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hex-3-yne, 4-methyl-2,2-di(t-butylperoxy)pentane and mixtures thereof.
Preferably, composition B comprises benzoyl peroxide.
Composition B may comprise a content of reducing agent ranging from 1% to 20%, preferably from 1% to 10%, by weight relative to the total weight of composition B.
The composition according to the invention can typically comprise a redox system, a reducing agent which is included in part A and an oxidizing agent which is included in part B. Mention may for example be made of the following combinations:
The two-component composition according to the invention can comprise at least one additive chosen from the group consisting of catalysts, fillers, antioxidants, light stabilizers/UV absorbers, metal deactivators, antistatics, antifogging agents, foaming agents, biocides, plasticizers, lubricants, emulsifiers, dyes, pigments, rheological agents, impact modifiers, adhesion promoters, optical brighteners, flame retardants, antisweating agents, nucleating agents, solvents and mixtures thereof.
These additives can be present in composition A and/or composition B of the composition according to the invention.
As examples of plasticizers that may be used, mention may be made of any plasticizer normally used in the field of adhesives, for instance epoxy resins, phthalates, benzoates, trimethylolpropane esters, trimethylolethane esters, trimethylolmethane esters, glycerol esters, pentaerythritol esters, naphthenic mineral oils, adipates, cyclohexyldicarboxylates, paraffinic oils, natural oils (optionally epoxidized), polypropylenes, polybutylenes, hydrogenated polyisoprenes, and mixtures thereof.
Preferably, use is made of:
As examples of (thixotropic) rheological agent(s) that may be used, mention may be made of any rheological agent customarily used in the field of adhesive compositions.
Preferably, the thixotropic agents are chosen from:
The composition according to the invention may also comprise at least one organic and/or mineral filler.
The mineral filler(s) that may be used is (are) advantageously chosen so as to improve the mechanical performance of the composition according to the invention in the crosslinked state.
As examples of mineral filler(s) that may be used, use may be made of any mineral filler(s) usually used in the field of adhesive compositions. These fillers are typically in the form of particles of diverse geometry. They may be, for example, spherical or fibrous or may have an irregular shape.
Preferably, the filler(s) is (are) chosen from the group consisting of clay, quartz, carbonate fillers, kaolin, gypsum, clays and mixtures thereof; preferentially, the filler(s) is (are) chosen from carbonate fillers, such as alkali metal or alkaline-earth metal carbonates, and more preferentially calcium carbonate or chalk.
These fillers may be untreated or treated, for example using an organic acid, such as stearic acid, or a mixture of organic acids predominantly consisting of stearic acid.
Use may also be made of hollow mineral microspheres, such as hollow glass microspheres, and more particularly those made of calcium sodium borosilicate or of aluminosilicate.
The composition according to the invention may also comprise at least one adhesion promoter, preferably chosen from silanes, such as aminosilanes, epoxysilanes or acryloyl silanes, or adhesion promoters based on a phosphate ester, such as for example the 2-hydroxyethyl methacrylate phosphate ester, 2-methacryloyloxyethyl phosphate, bis(2-methacryloyloxyethyl phosphate), 2-acryloyloxyethyl phosphate, bis(2-acryloyloxyethyl phosphate), methyl-(2-methacryloyloxyethyl phosphate), ethyl-(2-methacryloyloxyethyl phosphate), a mixture of 2-hydroxyethyl methacrylate mono- and diphosphate esters.
When a solvent, in particular a volatile solvent, is present in the composition, its content is preferably less than or equal to 5% by weight, more preferably less than or equal to 3% by weight, relative to the total weight of the composition.
Preferably, the content of solvent(s) in the composition is between 0% and 5% by weight.
When a pigment is present in the composition, its content is preferably less than or equal to 3% by weight, more preferably less than or equal to 2% by weight, relative to the total weight of the composition. When it is present, the pigment can, for example, represent from 0.1% to 3% by weight or from 0.4% to 2% by weight, of the total weight of the composition.
The pigments can be organic or inorganic pigments.
For example, the pigment is TiO2, in particular Kronos® 2059 sold by Kronos.
The composition can comprise an amount of from 0.1% to 3%, preferably from 1% to 3%, by weight of at least one UV stabilizer or antioxidant. These compounds are typically introduced in order to protect the composition from degradation resulting from a reaction with oxygen which is liable to be formed by the action of heat or light. These compounds may include primary antioxidants which trap free radicals. The primary antioxidants may be used alone or in combination with other secondary antioxidants or UV stabilizers.
Mention may be made, for example, of Irganox®1010, Irganox® B561, Irganox®245, Irgafos® 168, Tinuvin®328 or Tinuvin™ 770, which are sold by BASF.
According to one preferred embodiment, composition A comprises at least one acrylic block copolymer, preferably in a content ranging from 2% to 40% by weight, even more preferably from 5% to 20% by weight relative to the total weight of composition A. Acrylic block copolymers are typically impact modifiers.
The acrylic block copolymers can be copolymers comprising:
Preferably, the copolymers are triblocks comprising rigid block/flexible block/rigid block, wherein:
The rigid block (A) preferably comprises monomeric units derived from methyl methacrylate monomers.
The rigid block (A) may also comprise at least one dialkylacrylamide monomer, the linear or branched alkyl groups of which comprise from 1 to 10 carbon atoms, such as N,N-dimethylacrylamide.
The flexible block (B) preferably comprises monomeric units derived from at least one monomer chosen from butyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, 2-ethylhexyl methacrylate, n-octyl acrylate, and mixtures thereof.
Preferentially, the copolymer is a polymethyl methacrylate/poly(n-butyl acrylate)/polymethyl methacrylate block copolymer.
Among the acrylic block copolymers, mention may for example be made of Nanostrength® sold by Arkema (M52 comprising 52% by weight of poly(n-butyl acrylate), or M75 comprising approximately 75% by weight of poly(n-butyl acrylate), or M65 comprising approximately 65% by weight of poly(n-butyl acrylate)).
According to one preferred embodiment, composition B comprises at least one epoxy resin.
The epoxy resin may be aliphatic, cycloaliphatic, heterocyclic or aromatic.
The epoxy resin may be monomeric or polymeric.
The epoxy resins can be chosen from polyglycidyl ethers of polyphenolic compounds, preferably comprising from 2 to 6 glycidyl ether functions per mole of resin.
A phenolic compound is a compound having at least two aromatic hydroxyl groups.
The phenolic compounds can be chosen from the group consisting of resorcinol, catechol, hydroquinone, bisphenol A (2,2-bis-(4-hydroxyphenyl)propane), bisphenol AP (1,1-bis(4-hydroxyphenyl)-1-phenylethane), bisphenol AF (2,2-bis-(4-hydroxyphenyl)hexafluoropropane), bisphenol B ((2,2-bis(4-hydroxyphenyl)butane), bisphenol BP (bis(4-hydroxyphenyl)diphenylmethane), bisphenol C (2,2-bis(3-methyl-4-hydroxyphenyl)propane), bisphenol CII (bis(4-hydroxyphenyl)-2,2-dichloroethylene), bisphenol E (1,1-bis(4-hydroxyphenyl)ethane), bisphenol F (bis(4-hydroxyphenyl)-2,2-dichloroethylene), bisphenol FL (4,4′-(9H-fluoren-9-ylidene)bisphenol, bisphenol G (2,2-bis(4-hydroxy-3-isopropylphenyl)propane), bisphenol M (1,3-bis(2-(4-hydroxyphenyl)-2-propyl)benzene), bisphenol P (1,4-bis(2-4-hydroxyphenyl)-2-propyl)benzene), bisphenol PH (5,5′-(1-methylethylidene)-bis[1,1′-(bisphenyl)-2ol]propane), bisphenol S (bis(4-hydroxyphenyl)sulfone), bisphenol TMC (1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane); bisphenol Z (1,1-bis(4-hydroxyphenyl)cyclohexane), bisphenol K, tetraethylbiphenol, and mixtures thereof.
The epoxy resin can have an epoxy function content ranging from 0.3 to 10.8 meq per gram of resin.
Numerous epoxy resins are typically commercially available. Mention may for example be made of the D.E.R.™ 331 and D.E.R.™ 383 resins sold by Dow Chemicals, the Epon 862 resin sold by Hexion Specialty Chemicals, the Eposir® resins based on bisphenol A sold by SIR Industrial (for example Eposir®7120), and the Eposir® resins based on bisphenol A/bisphenol F (for example Eposir® F556).
According to one embodiment, the volume ratio of composition A/composition B in the composition of the invention ranges from 100/5 to 1/1, preferably from 20/1 to 1/1, preferably from 10/1 to 1/1.
According to a preferred embodiment, the abovementioned composition comprises:
relative to the total weight of composition A;
relative to the total weight of composition B.
Preferably, the composition according to the invention is an adhesive composition.
Ready-for-Use Kit
The present invention also relates to a ready-for-use kit comprising composition A as defined above, on the one hand, and composition B as defined above, on the other hand, packaged in two separate compartments. It can, for example, be a two-component cartridge.
This is because the composition according to the invention can be in a two-component form, for example within a ready-for-use kit, comprising composition A, on the one hand, in a first compartment or drum and composition B, on the other hand, in a second compartment or drum, in proportions suitable for direct mixing of the two components, for example by means of a metering pump.
According to one embodiment of the invention, the kit additionally comprises one or more means making possible the mixing of the compositions A and B. Preferably, the mixing means are chosen from metering pumps or static mixers with a diameter suited to the amounts used.
Uses of the Compositions
The present invention also relates to the use of a composition as defined above as adhesive, mastic or coating, preferably as adhesive.
The invention also relates to the use of said composition in the repair and/or the structural or semistructural adhesive bonding of materials in the transportation, motor vehicle (car, bus or truck), assembly, marine or construction field.
The present invention also relates to a method for assembling two substrates by adhesive bonding, comprising:
The crosslinking step can be carried out at a temperature between 0° C. and 200° C., preferably between 10° C. and 150° C., preferably between 23° C. and 80° C. and in particular between 20° C. and 25° C.
The crosslinking can also be induced using microwaves.
The appropriate substrates are, for example, inorganic substrates, such as concrete, metals or alloys (such as aluminum alloys, steel, non-ferrous metals and galvanized metals); or else organic substrates, such as wood, plastics, such as PVC, polycarbonate, PMMA, polyethylene, polypropylene, polyesters, epoxy resins; substrates made of metal and composites coated with paint.
The compositions according to the invention, once crosslinked, advantageously exhibit high resistance to high temperature.
The compositions according to the invention advantageously exhibit, after crosslinking, good adhesive properties.
All the embodiments described above can be combined with one another. In particular, the different abovementioned constituents of the composition, and especially the preferred embodiments of the composition, can be combined with one another.
In the context of the invention, the term “of between x and y” or “ranging from x to y” is understood to mean an interval in which the limits x and y are included. For example, the range “between 0% and 25%” includes in particular the values 0% and 25%.
The invention is now described in the following exemplary embodiments, which are given purely by way of illustration and should not be interpreted in order to limit the scope thereof.
The following ingredients were used:
The Priplast 3186 and Capa 2210 polyols were introduced into a reactor and heated at 90° C. under vacuum for approximately 1 h in order to dehydrate the polyols. Desmodur VK 10 was introduced into the reactor and heated at 70° C. for approximately 2 h. The reactor was then equipped with a reflux condenser. After a few minutes, the methyl methacrylate was introduced. Subsequently, the 2-hydroxyethyl methacrylate was introduced and the reaction medium was mixed at 70° C. for 1 h. The polyurethane P1 is obtained in solution in methyl methacrylate (solids content=65.8%).
44 MC
™ P2000
KAT 315
The Voranol™ P2000 polyol was introduced into a reactor and heated at 90° C. under vacuum for approximately 1 h in order to dehydrate the polyol. Desmodur 44 MC was introduced into the reactor and heated at 70° C. for approximately 2 h. After a few minutes, the catalyst and the 2-hydroxyethyl methacrylate were introduced, and the reaction medium was mixed at 60° C. for 1 h.
The various ingredients constituting the component A are mixed in the proportions shown in the following table, at a temperature of 23° C., in a reactor kept constantly stirred and under nitrogen.
The various ingredients constituting the component B are mixed in the proportions shown in the following table, at a temperature of 23° C., in a reactor kept constantly stirred and under nitrogen.
Composition No. 1 was prepared with the following ingredients:
3622
6700
ANS50
CL40
The component A comprises 6.58% by weight of the polyurethane P1 relative to the total weight of the component A ((65.8%×10%)/100=6.58%).
The component A and the component B above were mixed, in a 10:1 volume ratio.
The mixing is carried out at a temperature of approximately 23° C., according to the given ratio by volume, with a static mixer.
A comparative composition No. 2 was prepared in the same way with the following ingredients:
3622
6700
ANS50
CL40
The component A comprises approximately 5.26% by weight of the polyurethane P1 relative to the total weight of the component A ((65.8%×8%)/100=5.26%).
The component A and the component B above were mixed, in a 10:1 volume ratio.
The mixing is carried out at a temperature of approximately 23° C., according to the given ratio by volume, with a static mixer.
Measurement of the Breaking Strength by Tensile Testing:
The measurement of the strength (tensile strength) by tensile testing was performed according to the protocol described below.
The principle of the measurement consists in drawing, in a tensile testing device, the movable jaw of which moves at a constant rate equal to 100 mm/minute, a standard test specimen consisting of the crosslinked composition and in recording, at the moment when the test specimen breaks, the tensile stress applied (in MPa) and also the elongation of the test specimen (in %). The standard test specimen is dumbbell-shaped, as illustrated in the international standard ISO 37 of 2011. The narrow part of the dumbbell used has a length of 20 mm, a width of 4 mm and a thickness of 500 m.
Adhesive Bonding Tests
The adhesive bondings are produced on strips made of aluminum originating from Rocholl. A zone of 25*12.5 mm was delimited on a strip using wedges made of Teflon with a thickness of 250 μm a zone of 25*12.5 mm. This area was filled with the test composition and then a second strip of the same material was laminated. The combination was held by a clamp and placed in a climate-controlled chamber at 23° C. or at 100° C. and 50% RH (relative humidity) for a week before tensile testing on a universal testing machine. The aim of the tensile testing on a universal testing machine is to evaluate the maximum force (in MPa) to be exerted on the assemblage in order to separate it. Recourse to a tensile testing device makes it possible to subject a simple lap joint placed between two rigid supports to a shear stress up to failure by exerting tension on the supports parallel to the surface of the assemblage and to the main axis of the test specimen. The result to be recorded is the breaking force or stress. The shear stress is applied via the movable jaw of the tensile testing device with a displacement at the rate of 5 mm/min. This tensile testing method is carried out as defined by the standard EN 1465 of 2009.
The properties obtained for the compositions prepared are summarized in the table below:
Composition No. 1 advantageously results in adhesive bonding on aluminum leading to a cohesive failure (CF), which denotes in particular good adhesion in the automotive field compared to obtaining an adhesive rupture AR. In addition, the maximum force (Fmax) at the moment of rupture is advantageously higher at 23° C. and at high temperature (100° C.) than that obtained with comparative composition No. 2 having a content of polyurethane P1 of less than 6% by weight in the component A.
In addition, composition No. 1 advantageously results in an adhesive seal having, after crosslinking, a tensile strength greater than that obtained with composition No. 2 (comparative).
| Number | Date | Country | Kind |
|---|---|---|---|
| FR1903223 | Mar 2019 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2020/058295 | 3/25/2020 | WO | 00 |
