EP2646518A1

EP2646518A1 - Two-component curable composition

Info

Publication number: EP2646518A1
Application number: EP11788146.6A
Authority: EP
Inventors: Jens LÜCKERT; Lars Zander; Eric Rozier; Florent Villemagne
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 2010-11-30
Filing date: 2011-11-25
Publication date: 2013-10-09
Also published as: JP2014505743A; WO2012072504A1; US20130280530A1; CN103328597A; DE102010062186A1

Abstract

In the case of a curable composition based on at least one silyl-terminated polymer, the aim is to improve the adhesion spectrum in the bonding of plastics, and the rate of development of the adhesion. This is accomplished by provision of a curable composition comprising two components (1) and (2) that are not in contact with one another, where component (1) comprises at least one polymer having at least one end group of the formula (I) -A_n-CH₂-SiXYZ (I), in which A is a divalent linking group, X, Y and Z independently of one another are C₁ - C₈ alkyl, C₁ - C₈ alkoxy or C₁ - C₈ acyloxy groups, with at least one of the substituents being a C₁ - C₈ alkoxy or C₁ - C₈ acyloxy group, and n is 0 or 1; and with component (2) comprising at least water and at least one silanol condensation catalyst. The present invention further provides for the use of the composition of the invention as an adhesive and/or sealant.

Description

Two-component curable agent

The present invention is in the field of curable agents, such as those used in adhesives, sealants and coatings. In particular, the invention relates to a two-component, moisture-curable composition based on at least one silane-terminated polymer, a process for its preparation and its use.

Polymer systems that possess reactive silyl groups are known. In the presence of

Humidity are polymers which have silyl groups with hydrolyzable substituents, even at room temperature able to condense with elimination of the hydrolyzed radicals together. Depending on the content of silyl groups with hydrolyzable substituents and the structure of these silyl groups, mainly long-chain polymers (thermoplastics), relatively wide-mesh, three-dimensional networks (elastomers) or highly crosslinked systems (thermosets) are formed.

The polymers usually have an organic skeleton which ends at the ends

Example, alkoxy or Acyloxysilylgruppen carries. The organic skeleton may be, for example, polyurethanes, polyesters, polyethers, etc. Such α-ω-silane-substituted polymers are often characterized by high flexibility and cohesion.

For example, EP 0 931 800 A1 describes silylated polyurethanes which are obtained by reacting polyol components which have low terminal unsaturation with diisocyanates to give hydroxy-terminated prepolymers and subsequent capping with isocyanatosilanes. The polymers described are used for the production of sealants.

A composition based on silyl-terminated polyoxyalkylene polymers is also described in EP 1 396 513 A1. In a first variant, the composition contains both silyl-terminated polymers which have only one or two hydrolyzable groups, as well

Polymers having silyl end groups with three reactive groups. In a second variant, the two different types of silyl end groups are simultaneously present in a polyoxyalkylene polymer. According to EP 1 396 513 A1, such compositions are used in elastic, rapidly curing adhesives and sealants. The subject of WO 03/014226 A1 are one-component, alkoxy-crosslinking materials which contain, in addition to low molecular weight, especially substituted silanes, a polymer which has a

Hydrocarbon radical to the polymer skeleton bound terminal silyl groups containing one to three methoxy or ethoxy groups. In particular, the polymer may have end groups of the form -NR ¹ -CH ₂ -Si (R) a (CH ₃ ) 3-a (R = methoxy or ethoxy radical; R ¹ = hydrogen, alkyl or aryl radical; a = 1 to 3) , so-called α-silyl groups.

A curable composition comprising a hydrolyzable silyl group-containing organic polymer and, in addition, a tin-based curing catalyst is described in EP 1 304 354 A1.

For certain applications, in particular in the adhesive and sealant area, it is necessary to keep the time for fixing the substrates brought into contact as short as possible.

Nevertheless, of course, a good adhesion of the substrates to each other should be achieved. Such a problem is conceivable, for example, for industrial production lines, where after the bonding of certain parts as quickly as possible, the next processing step should take place, could interfere with the attached fixing devices. In addition, as universally applicable adhesives and sealants are of interest, which are characterized by good adhesion to different substrates. A particular challenge, but also particularly desirable, is often to achieve good adhesion when bonding plastics together.

It is therefore an object of the present invention to provide a curable composition which enables a rapid build-up of adhesion and stable, load-bearing adhesions when bonding plastics together. In addition, the agent should be applicable at room temperature and meet all general requirements that are placed on a modern adhesive and / or sealant. For example, the agent should have easy applicability and good physiological compatibility.

The object is solved by the subject matter of the present invention. The invention relates to a curable composition which comprises two components (1) and (2) which are not in contact with each other, component (1) comprising at least one polymer having at least one end group of the formula (I)

-A _n -CH ₂ SiXYZ (I) contains

wherein A is a divalent linking group containing at least one heteroatom,

X, Y, Z are substituents on the Si atom and independently of one another are C ₁ -C ₈ -alkyl, C ₁ -C ₈ -alkoxy or C ₁ -C ₈ -acyloxy radicals, where at least one of the substituents is a C - _\ - C ₈ - Alkoxy- or C _\ - C ₈ - Acyloxyrest, and

n is 0 or 1;

and component (2) contains at least water and at least one silanol condensation catalyst.

Such a composition shows a rapid cohesive structure and in particular also allows stable and durable bonding of plastics, such as polycarbonate or polypropylene together. In addition, the bonds or gaskets produced with it show sustained very good adhesion values.

The term "curable" is to be understood to mean that the agent is able, under the influence of external conditions, especially under the influence of existing in the environment and / or consciously supplied, possibly even in the medium existing moisture, from a plastically deformable In general, the curing can be effected by chemical and / or physical influences, in addition to the moisture already mentioned, for example, by supplying energy in the form of heat, light or other electromagnetic radiation, but also by simply contacting the agent with air or a reactive component.

The components (1) and (2) are not in contact with each other. This means that (1) and (2) are separated from one another, for example in two different containers, and consequently, in particular, can not enter into a chemical reaction with one another. This is possible only after the components have been brought together.

A "polymer" is understood to mean a substance which is composed of a large number of molecules in which one or more types of atoms or atomic groups (so-called constituent units, basic building blocks or repeating units) are repeatedly arranged next to one another present invention contains at least ten repeating units. Component (1) contains at least one polymer having at least one end group of the formula (I)

-A _n -CH ₂ SiXYZ (I).

The polymer of component (1) is preferably a polyether or a poly (meth) acrylic ester, and more preferably a polyether. A polyether is understood as meaning a polymer whose organic repeating units contain ether functionalities COC in the main chain. Thus, polymers containing pendent ether groups, such as, for example, the cellulose ethers, starch ethers and vinyl ether polymers, are not included among the polyethers. Also polyacetals, such as polyoxymethylene (POM) are generally not counted among the polyethers. A poly (meth) acrylic acid ester is understood as meaning a polymer based on (meth) acrylic acid esters, which therefore has as repeat unit the structural motif -CH ₂ -CR ^a (COOR ^b ) -, in which R ^{b is} linear, branched, cyclic and / or or functional substituents containing alkyl radicals, for example, methyl, ethyl, isopropyl, cyclohexyl, 2-ethylhexyl, or 2-hydroxyethyl radicals, and wherein R ^{a is} either a hydrogen atom (polyacrylic acid ester) or a methyl group (polymethacrylic acid ester) ,

Polymers containing polyether as a backbone have a flexible and elastic structure not only at the end groups but also in the polymer backbone. This can produce agents that have excellent elastic properties. Polyethers are not only flexible in their backbone but also stable at the same time. For example, they are not attacked or decomposed by water and bacteria. Polyethers based on polyethylene oxide and / or are particularly preferred in the context of the present invention

Polypropylene oxide, most preferably of polypropylene oxide, used in component (1).

Component (1) preferably contains at least one alkoxy- and / or acyloxysilane-terminated polyether which has a molecular weight M _n of 4,000 to 100,000, preferably 8,000 to 50,000, particularly preferably 10,000 to 30,000, in particular 15,000 to 25,000 g / mol. The molecular weight M _n is understood to mean the number average molecular weight of the polymer. For the purposes of the present invention, the number average molecular weight M _n as well as the weight average molecular weight M _{w is} determined by gel permeation chromatography (GPC) with polystyrene as standard. Such a method is known to the person skilled in the art. The given molecular weights are particularly advantageous because the corresponding means have a balance of viscosity (easy processability), strength and elasticity. Very advantageously, this combination is pronounced in a therefore preferred molecular weight range (M _n ) of from 12,000 to 30,000, more preferably from 14,000 to 27,000, and most preferably from 16,000 to 24,000 g / mol.

In the context of the present invention, component (1) preferably contains at least one polyether in which the ratio M _w / M _{n is} less than 1.5. The ratio M _w / M _n , which is also referred to as polydispersity, indicates the width of the molecular weight distribution and thus of the different degrees of polymerization of the individual chains in the case of polydisperse polymers. For many polymers and polycondensates, the polydispersity has a value of about 2. Strict monodispersity would be given at a value of 1. The preferred polydispersity of less than 1.5 in the context of the present invention indicates a comparatively narrow

Molecular weight distribution and thus on the specific expression of the molecular weight related properties, such as the viscosity, out. Particularly preferably, at least one alkoxy- and / or acyloxysilane-terminated polyether of component (1) has a polydispersity (M _w / M _n ) of less than 1.3.

The polyether (s) preferably used in component (1) is / are further preferably characterized by a low number of double bonds at the ends of the polymer chain. This so-called terminal unsaturation results from an undesirable side reaction in the polymerization of low molecular weight diols with alkylene oxides. As a result, there is a certain proportion of mono-hydroxypolyethers which can only be silylated at one end of the chain and accordingly also cross-link only via one end of the chain. This has detrimental effects on the functionality of the polyethers and the compositions made therefrom. Polyethers with a low number of terminal double bonds can be prepared, for example, by the so-called double metal cyanide catalysis (DMC catalysis). Preferably, component (1) contains at least one polyether having a terminal unsaturation of less than 0.07 meq / g as determined by the ASTM D4671 method.

The polymer (s) of component (1) has / have at least one end group of the formula (I)

-A _n -CH ₂ SiXYZ (I) in which

A is a divalent linking group containing at least one heteroatom,

X, Y, Z are substituents on the Si atom and independently of one another are C ₁ -C ₈ -alkyl, C ₁ -C ₈ -alkoxy or C ₁ -C ₈ -acyloxy groups, where at least one of the substituents is a C - _\ - C ₈ -

Alkoxy or C ₁ -C ₈ acyloxy group, and

n is 0 or 1.

A divalent or divalent bonding group A is understood as meaning a chemical group which links the polymer skeleton of the alkoxy- and / or acyloxysilane-terminated polymer with the methylene radical of the end group. The divalent linking group A can be formed, for example, in the preparation of an alkoxy- and / or acyloxysilane-terminated polyether or poly (meth) acrylic acid ester polymer, for example as a carbamate group by the reaction of a hydroxyl-functionalized polyether with an isocyanatosilane. In this case, the divalent binding group of structural features occurring in the underlying polymer backbone can be both distinguishable and indistinguishable. The latter is, for example, if it is identical to the points of attachment of the repeat units of the polymer backbone.

A is preferably an amide, carbamate or urethane, urea, imino, carboxylate, carbamoyl, amidino, carbonate, sulfonate or sulfinate group or an oxygen or

Nitrogen atom. Particularly preferably, the divalent linking group A in the formula (I) is a carbamate or urea group. These groups can be obtained by reacting certain functional groups of a prepolymer with an organosilane bearing a further functional group.

Under a carbamate or urethane group is a structural motif of the formula

-NH-C (0) -0- understood. Carbamate groups may be formed, for example, when either the polymer backbone contains terminal hydroxy groups and as further component isocyanatosilanes, or conversely, when a polymer having terminal isocyanate groups is reacted with a terminal hydroxy-containing alkoxysilane. Similarly, urinary groups can be obtained when a terminal primary or secondary amino group - either silane or polymer - is used which reacts with a terminal isocyanate group present in each reactant. That is, either an aminosilane having a terminal isocyanate group-containing polymer or a terminal amino-substituted polymer having an isocyanatosilane for reaction is brought. Accordingly, a urea group is understood to mean a structural motif of the formula -NH-C (O) -NR ° - where R ° is a hydrogen atom or any substituted or unsubstituted hydrocarbon radical.

Carbamate and urea groups advantageously increase the strength of the polymer chains and the entire crosslinked polymer.

The variable "n" can assume the value 0 or 1, that is to say the divalent linking group A links the polymer backbone with the methylene group (n = 1) or the polymer backbone is linked or linked directly to the methylene group (n = 0).

It has been found that the methylene group, which - optionally via the linking group A - links the polymer backbone with the silyl group, is of essential importance for the inventively particularly high reactivity of the final silyl group and thus for the shortened setting times and the very rapid curing of the formulations ,

X, Y and Z are independently C _\ - C ₈ - alkyl, C _\ - C ₈ - alkoxy or C _\ - C ₈ - acyloxy. At least one of the substituents X, Y, Z must be a hydrolyzable group that is a C _\ - C ₈ - alkoxy group or a C _\ - C ₈ - be acyloxy group. As hydrolyzable groups, preference is given to alkoxy groups, in particular methoxy, ethoxy, n-propyloxy, isopropoxy and butoxy groups. This is advantageous because curing of such agents containing alkoxy groups does not release substances irritating the mucous membranes. The alcohols formed are harmless in the released amounts and evaporate. Therefore, such funds are particularly suitable for the home improvement sector. As the hydrolyzable groups, however, acyloxy groups such as an acetoxy group -O-CO-CH ₃ can also be used.

Preferably, one of the substituents or radicals X, Y, Z in the formula (I) is a C ₁ -C ₈ -alkyl group, and the two other substituents are independently C ₁ -C ₈ -alkoxy groups, or all substituents X, Y and Z in the formula (I) are independently C ₁ -C ₈ -alkoxy groups. In general, polymers which contain di- or trialkoxysilyl groups have highly reactive attachment sites which enable rapid curing, high degrees of crosslinking and thus good final strengths. The particular advantage of dialkoxysilyl groups is that the corresponding agents are more elastic, softer and more flexible after curing than Trialkoxysilyl-containing systems. In addition, they cease even less alcohol when curing and are therefore of particular interest when the amount of alcohol released is to be reduced.

With trialkoxysilyl groups, on the other hand, a higher degree of crosslinking can be achieved, which is particularly advantageous if a harder, stronger mass is desired after curing. In addition, trialkoxysilyl groups are more reactive, ie they crosslink faster and thus reduce the required amount of catalyst, and they have advantages in the "cold flow" - the dimensional stability of a corresponding adhesive under the influence of force and possibly temperature.

The substituents X, Y and Z in the formula (I) are each preferably, independently of one another, a methyl, an ethyl, a methoxy or an ethoxy radical. Methoxy and ethoxy radicals as comparatively small hydrolyzable groups with low steric demand are very reactive and thus allow rapid curing even with little use of catalyst and thus allow rapid adhesion build-up and high initial tack.

Particularly preferably, X, Y and Z are each independently a methyl or a methoxy radical. Compounds with alkoxysilyl groups, depending on the nature of the alkyl radicals on

Oxygen atom different reactivities in chemical reactions. Within the alkoxy groups, the methoxy group shows the greatest reactivity. It is thus possible to resort to silyl groups of this type if particularly rapid curing is desired. Higher aliphatic radicals such as ethoxy bring about a lower reactivity of the terminal alkoxysilyl group compared to methoxy groups and can advantageously be used for the development of graduated crosslinking rates.

Interesting design options also open up combinations of both groups. If, for example, X is chosen to be methoxy and Y is ethoxy within the same alkoxysilyl group, the desired reactivity of the terminal silyl groups can be set particularly finely, if only silyl groups carrying methoxy groups are perceived as being too reactive and the ethoxy-bearing silyl groups too sluggish for the intended purpose.

In addition to methoxy and ethoxy groups, it is of course also possible to use larger radicals than hydrolyzable groups, which naturally have a lower reactivity. This is of particular interest, even if delayed curing is to be achieved via the design of the alkoxy groups.

The -SiXYZ group of the formula (1) is particularly preferably a methyldimethoxysilyl group. Such silyl groups have proven to be particularly suitable for obtaining stable bonds of plastics. In addition, they are also advantageous for the rapid adhesion of the compositions of the invention.

The alkoxy- and / or acyloxysilane-terminated polymer (s) of component (1) preferably has at least two end groups of the formula (I). Each polymer chain thus contains at least two linkage sites at which the condensation of the polymers can take place with elimination of the hydrolyzed radicals in the presence of atmospheric moisture. In this way, a regular and fast crosslinkability is achieved, so that bonds can be obtained with good strength. In addition, can be on the amount and structure of the hydrolyzable groups - for example, use of di- or Trialkoxysilylgruppen, methoxy groups or longer radicals, etc. - the design of the achievable network as a long-chain system (thermoplastics), relatively weitmaschiges three-dimensional network

(Elastomers) or highly cross-linked system (thermosets) control, so that among other things, the elasticity, the flexibility and the heat resistance of the finished cross-linked compositions can be influenced. It is further preferred that the alkoxy- and / or acyloxysilane-terminated polymers of component (1) have on average more than one end group of the formula (I), preferably 1, 1 to 5 end groups of the formula (I).

The polymer of component (1) particularly preferably has at least one end group of the formulas -O-CO-NH-CH ₂ -Si (OMe) ₂ Me or -N (R ¹ ) -CO-NH-CH ₂ -Si (OMe) ₂ Me, wherein R ^{1 is} an H atom or an alkyl group having 1 to 8 carbon atoms. Such end groups have proven to be particularly suitable to allow a quick adhesion and high adhesion, especially in the bonding of plastics with each other.

The total content of the component (1) of polymer (s) having at least one end group of the formula (I) is preferably 5 to 45% by weight, more preferably 10 to 40% by weight, especially 15 to 35% by weight most preferably 20 to 30 wt .-%, each based on the total weight of component (1). Polymers having at least one end group of the formula (I) are preferably contained in the agent according to the invention only in the component (1). The component (2) of the curable composition of the invention contains at least water and at least one silanol condensation catalyst. A silanol condensation catalyst is understood as meaning a compound which can catalyze the formation of an Si-O-Si bond with elimination of a water molecule from two Si-OH groups. The silanol condensation catalyst is preferably an organotin compound, a mono- or polyamine and / or a heterocyclic amine. The silanol condensation catalyst of the present invention is particularly preferably an organotin compound.

Suitable tin organyls are, for example, the 1, 3-dicarbonyl compounds of the two- or

tetravalent tin, for example the acetylacetonates such as di (n-butyl) tin (IV) di (acetylacetonate), di (n-octyl) tin (IV) di (acetylacetonate), (n-octyl) (n-butyl ) -zinn- (IV) -di (acetylacetonate); the dialkyltin (IV) -dicarboxylates, for example di-n-butyltin dilaurate, di-n-butyltin maleate, di-n-butyltin diacetate, di-n-octyltin diacetate or the corresponding dialkoxylates, for example di-n-butyltin dimethoxide; and the tin (II) carboxylates such as stannous octoate or stannous phenolate.

Furthermore, the following tin compounds are suitable: ethyl silicate, dimethyl maleate, diethyl maleate,

Dioctyl maleate, dimethyl phthalate, diethyl phthalate, dioctyl phthalate, di (n-butyl) tin (IV) di (methyl maleate), di (n-butyl) tin (IV) di (butyl maleate), di (n-octyl) tin (IV) -di (methyl maleate), di (n-octyl) tin (IV) di (butyl maleate), di (n-octyl) tin (IV) di (iso-octyl maleate), di (n-butyl) tin (IV) sulfide, di (n-butyl) tin (IV) oxide, di (n-octyl) tin (IV) oxide, (n-butyl) ₂ Sn (SCH ₂ COO), (n-octyl) ₂ Sn (SCH ₂ COO ),

Octyl) ₂ Sn (SCH ₂ CH ₂ COO), (n-octyl) ₂ Sn (SCH ₂ CH ₂ COOCH ₂ CH ₂ OCOCH ₂ S), (n-butyl) ₂ Sn (SCH ₂ COO-i-C ₈ H ₁₇ ) ₂ , (n-octyl) ₂ Sn (SCH ₂ COO-iC ₈ H ₁₇ ) ₂ , (n-octyl) ₂ Sn (SCH ₂ COO-nC ₈ H ₁₇ ) ₂ . The silanol condensation catalyst is particularly preferably a dialkyltin (IV) -dicarboxylate, in particular di-n-butyltin dilaurate.

Suitable mono- or polyamines are, for example, aliphatic monoamines such as butylamine, hexylamine, octylamine, decylamine or laurylamine; aliphatic diamines such as ethylenediamine or hexanediamine; aliphatic polyamines such as diethylenetriamine, triethylenetetramine or

tetraethylenepentamine; aromatic amines such as m-phenylenediamine; furthermore ethanolamine,

Triethylamine and modified amines, as they are also known as curing catalysts for epoxy resins. Examples of heterocyclic amines which can be used are N-methylpyrrolidine, N-methylpiperidine, N, N-dimethylpiperazine, diaza-bicyclo-octane (DABCO), N- (2-hydroxyethoxyethyl) -2-azanorbornane, 1,8-diazabicyclo (5.4.0 ) undec-7-ene (DBU), N-dodecyl-2-methylimidazole, N-methylimidazole, 2-ethyl-2-methylimidazole, N-methylmorpholine, bis (2- (2,6-dimethyl-4-morpholino) ethyl ) - (2- (4-morpholino) ethyl) amine, bis (2- (2,6-dimethyl-4-morpholino) ethyl) - (2- (2,6-diethyl-4-morpholino) ethyl) amine, Tris (2- (4-morpholino) ethyl) amine, tris (2- (4-morpholino) propyl) amine, tris (2- (4-morpholino) butyl) amine, tris (2- (2,6-dimethyl) 4-morpholino) ethyl) amine, tris (2- (2,6-diethyl-4-morpholino) ethyl) amine, tris (2- (2-methyl-4-morpholino) ethyl) amine, tris (2- (2 ethyl-4-morpholino) ethyl) amine, dimethylaminopropylmorpholine, bis (morpholinopropyl) methylamine, diethylaminopropylmorpholine, bis (morpholinopropyl) ethylamine, bis (morpholinopropyl) propylamine, morpholinopropylpyrrolidone, N-morpholinopropyl-N'-methyl- piperazine, dimorpholinodiethyl ether (DMDEE) or di-2,6-dimethylmorpholinoethyl) ether, as well as substituted guanidines.

1,8-Diazadicyclo (5.4.0) undec-7-ene (DBU) is particularly preferred.

The silane condensation catalyst is preferably in an amount of 0.01 to 3 wt .-%, more preferably from 0.05 to 2 wt .-%, in particular from 0.1 to 1, 5 wt .-% and most preferably from 0.3 to 1 wt .-%, each based on the total weight of component (2) of the inventive composition before. It is also possible to use mixtures of several catalysts. Preferably, only component (2) of the curable composition of the invention contains one or more silane condensation catalyst (s).

Water is preferably present in an amount of from 0.1 to 15% by weight, more preferably from 1 to 12% by weight, in particular from 2 to 10% by weight and most preferably from 4 to 8% by weight, each based on the total weight of component (2), before. Preferably, only component (2) of the curable composition of the invention contains water.

The components (1) and (2) of the composition according to the invention can in addition to the already

described contain other ingredients that give them, for example, improved elastic properties, improved resilience and low residual tackiness. These auxiliaries and additives include adhesion promoters, plasticizers and fillers. In addition, the agents may be used as further additives, for example stabilizers, antioxidants,

Reactive diluents, desiccants, UV stabilizers, anti-aging agents, rheological aids, color pigments or pastes, fungicides, flame retardants and / or optionally also contain small amounts of solvent. A plasticizer is understood to mean a substance which reduces the viscosity of the composition and thus facilitates the processability and, moreover, flexibility and flexibility

Improved elasticity of the agent.

In the context of the present invention, the plasticizer is preferably selected from a fatty acid ester, a dicarboxylic acid ester, an ester OH groups or epoxidized fatty acids, a fat, a glycolic acid ester, a phthalic acid ester, a benzoic acid ester, a phosphoric acid ester, a sulfonic acid ester, a trimellitic acid ester, a

epoxidized plasticizer, a polyether plasticizer, a polystyrene, a hydrocarbon plasticizer and a chlorinated paraffin, and mixtures of two or more thereof. By the specific choice of one of these plasticizers or a specific combination, further advantageous properties of the agents according to the invention, for example

Geliervermögen the polymers, cold elasticity or cold resistance or antistatic properties can be realized.

For example, dioctyl phthalate, dibutyl phthalate, diisodecyl phthalate, diisoundecyl phthalate, diisononyl phthalate or butyl benzyl phthalate are dioctyl adipate, diisodecyl adipate, diisodecyl succinate, dibutyl sebacate or butyl oleate, among the adipates. Of the polyether plasticizers are preferably used end-capped polyethylene glycols, for example, polyethylene or polypropylene glycol di-C ^ alkyl ethers, in particular the dimethyl or diethyl ether of diethylene glycol or dipropylene glycol, and mixtures of two or more thereof. Also suitable as plasticizers are, for example, esters of abietic acid,

Butyric acid esters, acetic acid esters, propionic acid esters, thiobutyric acid esters, citric acid esters and esters based on nitrocellulose and polyvinyl acetate, and mixtures of two or more thereof.

Also suitable, for example, are the asymmetric esters of adipic acid monooctyl ester with 2-ethylhexanol (Edenol DOA, Cognis Deutschland GmbH, Dusseldorf). In addition, the pure or mixed ethers of monofunctional, linear or branched C ₄ are suitable as plasticizers. ₁₆ -alcohols or mixtures of two or more different ethers of such alcohols,

for example, dioctyl ether (available as Cetiol OE, Cognis Germany GmbH, Dusseldorf). Likewise suitable as plasticizers in the context of the present invention are diurethanes which can be prepared, for example, by reacting diols having OH end groups with monofunctional isocyanates, by selecting the stoichiometry such that essentially all free OH groups react. Optionally, excess isocyanate can then be removed from the reaction mixture, for example by distillation. Another method for the preparation of diurethanes is the reaction of monofunctional alcohols with diisocyanates, where possible all of the NCO groups react.

In the context of the present invention is preferred in both components of the composition

Contain softener. In the component (1), plasticizer (s) is preferably in an amount of from 1 to 40% by weight, more preferably from 5 to 35% by weight, especially from 10 to 30% by weight, and most preferably from 15 to 30 wt .-%, each based on the

Total weight of component (1) included. In the component (2), plasticizer (s) is preferably in an amount of from 20 to 95% by weight, more preferably from 30 to 85% by weight, especially from 40 to 80% by weight, and most preferably from 50 to 70 wt .-%, each based on the total weight of component (2) included.

A viscosity of the agent according to the invention that is too high for certain applications can also be reduced in a simple and expedient manner by using a reactive diluent without causing any segregation (for example plasticizer migration) in the hardened mass. The reactive diluent preferably has at least one functional group which reacts with moisture or atmospheric oxygen, for example after application. Examples of such groups are silyl groups, isocyanate groups, vinylic

unsaturated groups and polyunsaturated systems. Reactive diluents which can be used are all compounds which are miscible with the composition according to the invention with reduction in viscosity and have at least one group reactive with the binder, alone or as a combination of several compounds. The viscosity of the reactive diluent is preferably less than 20,000 mPas, more preferably about 0, 1-6,000 mPas, most preferably 1-1,000 mPas (Brookfield RVT, 23 ° C, spindle 7, 10 U / min).

The following substances can be used as reactive diluents: polyalkylene glycols reacted with isocyanatosilanes (for example Synalox 100-50B, DOW), alkyltrimethoxysilane, alkyltriethoxysilane, such as methyltrimethoxysilane, methyltriethoxysilane and vinyltrimethoxysilane (XL 10, Wacker), phenyltrimethoxysilane, phenyltriethoxysilane, octyltrimethoxysilane, tetraethoxysilane, Vinyldimethoxymethylsilane (XL12, Wacker), vinyltriethoxysilane (GF56, Wacker), vinyltriacetoxysilane (GF62, Wacker), isooctyltrimethoxysilane (IOtrimethoxy), isooctyltriethoxysilane (IOtriethoxy, Wacker), N-trimethoxysilylmethyl-O-methylcarbamate (XL63, Wacker), N- Dimethoxy (methyl) silylmethyl O-methyl carbamate (XL65, Wacker), hexadecyltrimethoxysilane, 3-octanoylthio-1 propyltriethoxysilane and partial hydrolysates of these compounds. Further, the following polymers are also available from Kaneka Corp. can be used as reactive diluents: MS S203H, MS S303H, MS SAT 010, and MS SAX 350. Further suitable as reactive diluents are polymers which can be prepared from an organic skeleton by grafting with a vinyl silane or by reacting polyol, polyisocyanate and alkoxysilane.

A polyol is understood as meaning a compound which contains a plurality of OH groups in the molecule. The OH groups can be both primary and secondary. Suitable aliphatic alcohols include, for example, ethylene glycol, propylene glycol and higher glycols, as well as other polyfunctional alcohols. The polyols can also be further functional

Contain groups such as esters, carbonates, amides. For the production of a

Reactive thinner by reaction of polyol with polyisocyanate and alkoxysilane, the corresponding polyol component is reacted with an at least difunctional isocyanate. In principle, any isocyanate having at least two isocyanate groups is suitable as the at least difunctional isocyanate, but in the context of the present invention, as a rule, compounds having two to four isocyanate groups, in particular two, are used

Isocyanate groups are preferred. Among the alkoxysilyl groups, the di- and trialkoxysilyl groups are preferred.

Suitable polyisocyanates for preparing a reactive diluent are, for example, ethylenediisocyanate, 1,4-tetramethylene diisocyanate, 1,4-tetramethoxybutane diisocyanate, 1,6-hexamethylene diisocyanate (HDI), cyclobutane-1,3-diisocyanate, cyclohexane-1, 3. and -1, 4-diisocyanate, bis (2-isocyanato-ethyl) fumarate, and mixtures of two or more thereof, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 2,4 and 2,6-hexahydrolidinylene diisocyanate, hexahydro-1,3-or 1,4-phenylene diisocyanate, benzidine diisocyanate, naphthalene-1, 5-diisocyanate, 1,6-diisocyanato-2,2,4-trimethylhexane, 1, 6-diisocyanato-2,4,4-trimethylhexane, xylylenediisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), 1,3- and 1,4-phenylenediisocyanate, 2,4- or 2,6-toluene diisocyanate (TDI) thandiisocyanat, ^{2,4-diphenylmethane} diisocyanate, 2,2 ^{'-Diphenylme-} or ^{4,4'-diphenylmethane} diisocyanate (MDI) or their partially or completely hydrogenated cycloalkyl, beis pielsweise fully hydrogenated MDI (H12-MDI), alkyl substituted diphenylmethane diisocyanates, for example mono-, di-, tri- or Tetraalkyldiphenylme- thandiisocyanat and their partially or completely hydrogenated cycloalkyl, 4,4 ^'- diisocyanatophenyl, phthalic acid-bis-isocyanatoethyl ester, 1 -Chlormethylphenyl -2,4- or 2,6-diisocyanate, 1-bromomethylphenyl-2,4- or 2,6-diisocyanate, 3,3-bis-chloromethyl ether 4,4 ^{'-diphenyldiisocyanat,} sulfur-containing diisocyanates such as those obtainable by reaction of 2 mol of diisocyanate with 1 mol thiodiglycol or dihydroxydihexyl, the di- and

Triisocyanates of di- and trimer fatty acids, or mixtures of two or more of said diisocyanates.

Likewise, as polyisocyanates, it is possible to use trihydric or higher isocyanates, as obtainable, for example, by oligomerization of diisocyanates, in particular by oligomerization of the abovementioned isocyanates. Examples of such trihydric and higher polyisocyanates are the triisocyanurates of HDI or IPDI or mixtures thereof or their mixed triisocyanurates and polyphenylmethylene polyisocyanate, as obtainable by phosgenation of aniline-formaldehyde condensation products.

To reduce the viscosity of the composition according to the invention, it is also possible to use solvents in addition to or instead of a reactive diluent. Suitable solvents are aliphatic or aromatic hydrocarbons, halogenated hydrocarbons, alcohols, ketones, ethers, esters, ester alcohols, keto alcohols, keto ethers, keto esters and ether esters. Preferably, however, alcohols are used, since in this case the storage stability increases. C 1 -C 4 -alcohols, especially methanol, ethanol, i-propanol, isoamyl alcohol and hexanol are particularly preferred.

The composition according to the invention may additionally comprise a bonding agent. Under a

Adhesion promoter is understood to mean a substance which improves the adhesion properties of adhesive layers on surfaces. Conventional adhesion promoters (tackifiers) known to the person skilled in the art can be used alone or as a combination of several compounds. For example, resins, terpene oligomers, coumarone / indene resins, aliphatic, petrochemical resins, and modified phenolic resins are suitable. Hydrocarbon resins, for example, which are obtained by polymerization of terpenes, principally α- or β-pinene, dipentene or limonene, are suitable in the context of the present invention. The polymerization of these monomers is usually cationic with initiation with Friedel-Crafts catalysts. The terpene resins also include copolymers of terpenes and other monomers, for example styrene, α-methylstyrene, isoprene and the like. The resins mentioned are used, for example, as adhesion promoters for pressure-sensitive adhesives and coating materials. Also suitable are the terpene-phenolic resins prepared by acid catalyzed addition of phenols to terpene or rosin. Terpene-phenolic resins are most organic Solvents and oils soluble and miscible with other resins, waxes and rubber.

Likewise suitable in the context of the present invention as adhesion promoters in the abovementioned sense are the rosins and their derivatives, for example their esters or alcohols. Silane coupling agents, in particular aminosilanes, are particularly suitable.

In a specific embodiment of the curable composition of the invention, the composition comprises a silane of the formula (II)

R ^' R ^" NR ^"' -SiXYZ (II) as a primer, wherein

R ^' and R ^" independently of one another represent hydrogen atoms or C ₁ -C ₈ -alkyl radicals,

R ^'"is a divalent hydrocarbon radical optionally containing a heteroatom with 1 -

12 C atoms, and

X, Y, Z independently of one another are C ₁ -C ₈ -alkyl, C ₁ -C ₈ -alkoxy or C ₁ -C ₈ -acyloxy radicals, where at least one of the substituents X, Y, Z is a is acyloxy - _\ - C ₈ - alkoxy or C _\ - C. ₈

By nature, such compounds have a high affinity for the binding

Polymer components of the curable composition according to the invention, but also to a wide range of polar and non-polar surfaces and therefore contribute to the formation of a particularly stable adhesion between the adhesive composition and the substrates to be bonded in each case.

The linking group R ^'" may be, for example, a straight-chain or branched or cyclic, substituted or unsubstituted alkylene radical. Optionally, the heteroatom contained therein is nitrogen (N) or oxygen (O)

Acyloxy group, this may be, for example, the acetoxy group -OCO-CH ₃ .

In the context of the present invention, an adhesion promoter is preferably contained in component (1).

Suitable fillers for the composition according to the invention are, for example, chalk, limestone, precipitated and / or fumed silica, zeolites, bentonites, magnesium carbonate, kieselguhr, clay, clay, Talc, titanium oxide, iron oxide, zinc oxide, sand, quartz, flint, mica, glass powder and other ground minerals. Furthermore, organic fillers can be used, in particular carbon black, graphite, wood fibers, wood flour, sawdust, pulp, cotton, pulp, wood chips, chaff, chaff, ground walnut shells and other fiber short cuts. Furthermore, short fibers such as glass fiber, glass filament, polyacrylonitrile, carbon fiber, Kevlar fiber or even polyethylene fibers can be added. Aluminum powder is also suitable as a filler. In addition, suitable fillers are hollow spheres with a mineral shell or a plastic shell. These may be, for example, glass bubbles, which are commercially available under the trade names Glass Bubbles®. Plastic-based hollow spheres, for example Expancel® or Dualite®, are composed of inorganic or organic substances, each with a diameter of 1 mm or less, preferably of 500 μm or less. For some applications, fillers are preferred which impart thixotropy to the formulations. Such fillers are also described as rheological aids, for example hydrogenated castor oil, fatty acid amides or swellable plastics such as PVC.

Preferably, both components of the curable composition according to the invention contain a filler or a combination of several fillers. Filler (s) is / are in the component (1) preferably in an amount of 20 to 80 wt .-%, particularly preferably from 30 to 70 wt .-%, in particular from 40 to 60 wt .-%, and most preferably from 43 to 55 wt .-%, each based on the total weight of component (1). The component (2) contains preferably 10 to 50 wt .-%, particularly preferably 15 to 45 wt .-%, in particular 20 to 40 wt .-% and most preferably 25 to 35 wt .-% filler (s), respectively based on the total weight of component (2).

For example, the filler used is a finely divided silica having a BET surface area of from 10 to 500 m ² / g. When used, such a silica does not cause any

significant increase in the viscosity of the composition according to the invention, but contributes to a

Reinforcement of the cured preparation at. About this gain, for example, the initial strength, tensile shear strength and adhesion of the adhesive, sealing or

Coating materials in which the agent according to the invention is used, improved. Preference is given to uncoated silicas having a BET surface area of less than 100, more preferably less than 65 m ² / g, and / or coated silicas having a BET surface area of from 100 to 400, more preferably from 100 to 300, in particular from 150 to 300 and most preferably from 200 to 300 m ² / g used. The filler may also be a zeolite or a mixture of different zeolites. As zeolite alkali-alumino-silicates are preferably used, for example, sodium potassium alumino-silicates of the general empirical formula aK ₂ 0 ^* BNA ₂ 0 ^* Al ₂ 0 ₃ ^* 2SiO ^* nH ₂ 0 with 0 <a, b <1 and a + b = 1 ,

Preferably, the pore opening of the zeolite or zeolites used is just large enough to accommodate water molecules. Accordingly, an effective pore opening of the zeolites of less than 0.4 nm is preferred. The effective pore opening is particularly preferably 0.3 nm ± 0.02 nm. The zeolite (s) is / are preferably used in the form of a powder.

The agent according to the invention particularly preferably contains one or more chalk (s) as filler. As chalk, cubic, non-cubic, amorphous and other modifications of calcium carbonate can be used. Preferably, the or at least one of the used chalk (s) is surface-treated or coated. The coating agents used are preferably fatty acids, fatty acid soaps and fatty acid esters, for example lauric acid, palmitic acid or stearic acid, sodium or potassium salts of such acids or their alkyl esters. In addition, however, other surface-active substances such as

Sulfate esters of long-chain alcohols or alkylbenzenesulfonic acids or their sodium or potassium salts or coupling reagents based on silanes or titanates in question. With the surface treatment of the chalks is often an improvement of the

Processability as well as the bond strength and also the weather resistance of the compositions. The coating composition is usually used in an amount of from 0.1 to 20% by weight, preferably from 1 to 5% by weight, based on the total weight of the crude crayon. With particular preference, a mixture of surface-treated and non-surface-treated chalk is used as the filler in the composition according to the invention.

Depending on the desired property profile, precipitated or ground chalks can be used. Ground chalks can be made, for example, from natural lime, limestone or marble by mechanical grinding, using dry or wet methods. Depending on the milling process, fractions with different average particle size are obtained. Advantageous specific surface values (BET) are between 1.5 m ² / g and 50 m ² / g. Furthermore, the agent according to the invention may contain antioxidants, which are particularly preferably present in component (1). Preferably, the proportion of the antioxidants in the component (1) is up to about 4 wt .-%, in particular up to about 1 wt .-%, based on the total weight of component (1). The agent according to the invention may additionally contain UV stabilizers, which are preferably present in component (1). The proportion of UV stabilizers on component (1) is preferably up to about 1% by weight, in particular up to about 0.2% by weight. Particularly suitable as UV stabilizers are the so-called hindered amine light stabilizers (HALS). It is preferred in the context of the present invention if a UV stabilizer is used which carries a silyl group and is incorporated into the final product during crosslinking or curing. Particularly suitable for this purpose are the products Lowilite 75, Lowilite 77 (Great Lakes, USA). It is also possible to add benzotriazoles, benzophenones, benzoates, cyanoacrylates, acrylates, sterically hindered phenols, phosphorus and / or sulfur.

Often it makes sense to further stabilize the component (1) of the agent according to the invention against penetrating moisture in order to increase the shelf life even more. Such an improvement in shelf life can be achieved, for example, by the use of desiccants. Suitable drying agents are all compounds which react with water to form an inert group with respect to the reactive groups present in the composition, and thereby undergo the smallest possible changes in their molecular weight. Furthermore, the reactivity of the desiccants to moisture penetrated into the composition must be higher than the reactivity of the end groups of the

Composition of present invention silyl groups bearing polymer. Suitable drying agents are, for example, isocyanates.

Silanes are also advantageously used as drying agents, for example vinyl silanes such as 3-vinylpropyltriethoxysilane, oxime silanes such as methyl-0,0 ^' , 0 ^" -butan-2-one-trioximosilane or

0,0 ^' , 0 ^" , 0 ^"' butan-2-one tetraoximosilane (CAS Nos. 022984-54-9 and 034206-40-1) or

Benzamidosilanes such as bis (N-methylbenzamido) methylethoxysilane (CAS No. 16230-35-6) or carbamatosilanes such as carbamatomethyltrimethoxysilane. But the use of methyl, ethyl or vinyltrimethoxysilane, tetramethyl or -ethylethoxysilane is possible. Vinyl trimethoxysilane and tetraethoxysilane are particularly preferred in terms of efficiency and cost. Also suitable as a desiccant are the reactive diluents mentioned above, provided they have a molecular weight (M _n ) of less than about 5,000 g / mol and have end groups whose reactivity to moisture penetration is at least as great, is preferably greater than the reactivity of the reactive groups of the silyl group-carrying polymer according to the invention. Finally, it is also possible to use alkyl orthoformates or orthoacetates as drying agents, for example methyl or ethyl orthoformate, methyl or ethyl orthoacetate. The agent according to the invention preferably contains in the component (1) preferably 0.01 to 5 wt .-%, particularly preferably 0, 1 to 2 wt .-% drying agent, based on the total weight of component (1).

Preferably, the agent according to the invention in component (1) contains a) 10-40% by weight of polymer having at least one end group of

Formula (I),

b) 30-70% by weight of filler,

c) 5-30% by weight of plasticizer

d) 0-10% by weight of auxiliaries and in component (2) e) 0-50% by weight of filler,

f) 30-95% by weight of plasticizer or reactive diluent,

g) 1 -10% by weight of water

h) 0.05-2 wt .-% silanol condensation catalyst

i) 0-5 wt .-% further excipients, wherein the wt .-% - are in each case based on the total weight of the corresponding component and the proportions of the ingredients in both components add up to 100 wt .-%. This means that, for example, the 30-70% by weight of filler in component (1) is based on the total weight of component (1) and furthermore that, for example, the addition of the weight proportions of the components of component (1) is 100% by weight. results.

The formulation of the compositions according to the invention as a multicomponent system is essential for a successful application. A one-component formulation containing the ingredients listed above except for water in corresponding proportions did not show satisfactory cure. It is provided according to the invention to mix the components (1) and (2) of the curable composition before use, wherein the weight ratio of component (1) to component (2) preferably from 2: 1 to 8: 1, particularly preferably from 3 : 1 to 7: 1, in particular from 4: 1 to 6: 1.

Another object of the present invention is the use of the curable composition according to the invention as an adhesive and / or sealant. It has already been described herein that the composition according to the invention enables rapid bonding with good adhesion.

Particularly preferred is the use of the agent according to the invention as an adhesive for

Bonding of plastics, in particular of synthetic thermoplastics, for example of polycarbonate and polypropylene or else polyacrylate. In particular, stable bonds of such plastic substrates can be achieved if at least one of the substrates is transparent. By way of example, the transparent substrate is polycarbonate or polyacrylate. A very particularly preferred use of the agent according to the invention is the use as an adhesive for bonding headlights in vehicles, wherein a transparent component is glued in a designated socket.

Examples

Producing the specimens for the tensile shear test

Immediately before the preparation of the test specimens, the two-component adhesive / sealant is made ready for use by intensive mixing of the two components (60 s).

Three test specimens are required per measurement. Substrate bodies with a total length of 7.3 cm are used which have a square area of 2x2 cm at one end. This square surface of a substrate body is coated with the adhesive / sealant to be tested. As a spacer four 2mm thick metal balls are placed in the adhesive / sealant film. Then, a second substrate body with the same surface is placed on the adhesive / sealant and pressed together with his hands until caused by the metal balls conditionally a 2mm thick adhesive / sealant film between the two substrate bodies. Leaking material is removed with a spatula. Now the specimens at 23 ° C for

stored different time.

Pulling shear test - carrying out the measurement

The specimens are stretched to the breaking point after the intended time in a tensile machine. The maximum force value is determined and an average value per time unit is formed from the three measurements.

Formulations according to Table 1 with varying polymers (see Table 2) were prepared, wherein the individual components were prepared by mixing in a Speedmixer (30 s):

Table 1: Formulations

Components (1) and (2) were mixed in a weight ratio of 100:19.

With compositions according to Table 1, the results listed in Table 2 below were achieved on the basis of two different polymers.

Table 2: Results as a function of the polymer used

Polycarbonate used (PC): Makroion 2447 (Bayer)

Polypropylene used (PP): Targor (Hoechst)

kB = cohesive fracture pattern (break within the adhesive layer)

aB = adhesive fracture pattern (break between substrate and adhesive layer) The composition according to the invention has consistently a cohesive fracture pattern (break within the adhesive layer) during the tensile shear test and therefore outstanding adhesion to the substrate. On the other hand, the tensile shear test with the formulation which is not according to the invention gives rise to an adhesive fracture pattern several times (breakage between the adhesive layer and the substrate) and thus indicates insufficient adhesion between the substrate and the adhesive. The results therefore show that stable bonding of plastics can be carried out with the composition according to the invention, in contrast to the noninventive formulation.

With the formulations according to Tables 1 and 2, experiments were carried out to determine the cohesive structure. For this purpose, tensile shear tests were carried out with polypropylene test specimens (PP / PP) after 4, 6, 7, 8, 9 and 10 minutes. The results are summarized in Table 3 below.

Table 3: Cohesion Building Results

The results show the faster cohesive structure of the formulation according to the invention.

Claims

claims

A curable composition containing two non-contacting components (1) and (2), wherein

Component (1) at least one polymer having at least one end group of the formula (I)

-A _n -CH ₂ SiXYZ (I) wherein

A is a divalent linking group containing at least one heteroatom,

X, Y, Z are substituents on the Si atom and independently of one another Ci - C ₈ - alkyl, Ci - C ₈ -

Alkoxy or - C ₈ - Acyloxyreste are where at least one of the substituents

- C ₈ - alkoxy or - C _{8 is} acyloxy, and

n is 0 or 1; and component (2) contains at least water and at least one silanol condensation catalyst.

A curable composition according to claim 1, characterized in that the divalent binding group A in the formula (I) is a carbamate or urea group.

A curable composition according to claim 1 or 2, characterized in that X, Y, Z in the formula (I) are each independently a methyl, an ethyl, a methoxy or an ethoxy radical.

Hardenable agent according to at least one of the preceding claims, characterized in that the -SiXYZ group of the formula (1) is a methyldimethoxysilyl group.

Curable composition according to at least one of the preceding claims, characterized in that the polymer of component (1) at least one end group of the formulas -O-CO-NH-CH ₂ -Si (OMe) ₂ Me or -N (R ¹ ) -CO -N H-CH ₂ -Si (OMe) ₂ Me, wherein R ^{1 is} an H atom or an alkyl group having 1 to 8 C atoms.

6. A curable composition according to any one of the preceding claims, characterized in that the total content of polymers having at least one end group of the formula (I) is 5 to 50 wt .-%, based on the total weight of the composition.

7. curable agent according to any one of the preceding claims, characterized

in that the polymer of component (1) is a polyether.

8. curable agent according to any one of the preceding claims, characterized

in that the agent in component (1) a. 10-40 wt .-% of polymer having at least one end group of

Formula (I),

b. 30-70% by weight of filler,

c. 5-30% by weight of plasticizer

d. 0-10 wt .-% excipients and in component (2) e. 0-50 wt.% Filler,

f. 30-95% by weight of plasticizer,

G. 1 -10% by weight of water

H. 0.05-2 wt .-% silanol condensation catalyst

i. 0-5 wt .-% further auxiliaries, wherein the wt .-% - in each case based on the total weight of the corresponding

Component are related and the proportions of the ingredients in both components add up to 100 wt .-%.

9. Use of a curable composition according to any one of claims 1 to 9 as an adhesive and / or sealant.

10. Use according to claim 9 as an adhesive for bonding synthetic thermoplastics.