EP0431026A1

EP0431026A1 - New multiple-constituent mixtures capable of free-radical polymerization and their use

Info

Publication number: EP0431026A1
Application number: EP89909733A
Authority: EP
Inventors: Thomas Huver; Herbert Fischer; Winfried Emmerling
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 1988-08-31
Filing date: 1989-08-22
Publication date: 1991-06-12
Also published as: BR8907627A; ATE89011T1; WO1990002143A1; US5268436A; MX170439B; CA1338498C; EP0356875A1; JP2763810B2; DE3829438A1; ZA896648B; DE58904261D1; AU627776B2; HK128694A; KR900701854A; IE63522B1; EP0356875B1; JPH04500227A; AU4194389A; IE892780L; ES2041913T3

Abstract

PCT No. PCT/EP89/00982 Sec. 371 Date Feb. 27, 1991 Sec. 102(e) Date Feb. 27, 1991 PCT Filed Aug. 22, 1989 PCT Pub. No. WO90/02143 PCT Pub. Date Mar. 8, 1990.The invention relates to moldable, radically polymerizable multicomponent mixtures containing ethylenically unsaturated, polymerizable compounds, if desired in admixture with soluble and/or insoluble fillers and an activator system initiatable by contact with oxygen, and is characterized in that these multicomponent mixtures contain an activator system based on the following principal components which can be initiated by contact with oxygen and water and, in particular, by contact with ambient air: N-alkyl-substituted tert-arylamines containing at least one aliphatic CH bond in the alpha -position metal compounds at least partly soluble in the system to accelerate the drying of unsaturated oils and compounds of weakly acidic carboxylic acids having pKa values of no less than about 0.9 which can be hydrolyzed to the free carboxylic acid on contact with moisture. The invention also relates to the use of these multicomponent mixtures as an aerobic adhesive system, more particularly in the form of a one-component adhesive packed in storable form, and to their use for surface coating or for the production of plastic moldings.

Description

"New Radically Polymerizable Multi-Compound Mixtures and Their Use (I)"

The invention relates to novel, formally processable, free-radically polymerizable multicomponent mixtures which are used, for example, as flowable or spreadable compositions or as pasty compositions and then harden under ambient conditions and triggering the polymerization reaction. In terms of application technology, the invention relates to almost all areas of the use of free-radically polymerizable or curable compositions. Examples include adhesives, sealing compounds, the targeted structure of plastic molded parts, the surface coating with air-curing, in particular solvent-free, coating systems and the like.

The peroxide or. Hydroperoxide-initiated curing of olefinically unsaturated systems requires activator systems composed of several components in particular if the reaction is to be triggered at low temperatures, for example at room temperature or only slightly elevated temperatures. It is known that selected tertiary amine compounds with partial aromatic substitution on the N atom have such an activator function. Known activators for triggering polymerization, for example using benzoyl peroxide, are in particular dimethylaniline and dimethyl-p-toluidine.

A completely different known class of activator for the oxidative polymerization initiation of certain unsaturated systems, namely drying oils, are in the system at least partially soluble metal compounds of such metals, which are combined with several Levels of value can occur and accelerate the start reaction by means of intermediate shifts in the value when interacting with other components of the system. Such metal compounds of such metals which are sufficiently soluble in organic solvents and / or in binders have long been known as so-called drying agents for air drying paints, varnishes and the like based on unsaturated oils. Sufficiently oil-soluble compounds of such transition metals which are capable of occurring in several valence stages are particularly suitable here. The ability to accelerate hardening is differently pronounced in the individual components, primarily cobalt and / or manganese compounds are considered, but iron also accelerates hardening. In addition and in particular in combination with these highly effective metallic components, comparable compounds of other metals can be used, which may also be capable of forming several valency levels. A detailed description of such systems can be found, for example, in ^** Ul! Mann Encyklopadie der Technische Chemie ", 4th edition, volume 23 (1983), 421 to 2.

It is also known that the two types of promoters for radical polymerization initiation described here can lead to an increase in activity through interaction. For example, the publication by L. HORNER et al. "Autoxidation studies on N, N-dialkylated aniline derivatives", Makromolekulare Chemie 93 (1966), 69 to 108, studies to accelerate the spontaneous autoxidation of such N-dialkyl-substituted arylamine compounds in pure, highly dry oxygen gas. In the first stage of spontaneous autoxidation, the amine hydroperoxide compound is formed when exposed to dried ultrapure oxygen. alpha-standing alϊphatic CH groups. This spontaneous autoxidation of the N, N-dialkylated Arylamine is slow. The concomitant use of cobalt II compounds and to a lesser extent the concomitant use of iron II salts leads to the activation of the autoxidation according to the information in this publication. Further work in this publication shows that acetic acid is also said to have a pronounced acceleration effect of the autoxidation on the tert-amine compound, whereas stronger acids such as trichloroacetic acid or mineral acids form true tert. - ammonium salts that are not autoxidable. The combined use of cobalt ions and acetic acid leads to the lively catalyzed autoxidation of dialkylaniline compounds under the action of ultrapure oxygen.

Finally, the cited publication describes some investigations for triggering the polymerization of vinyl compounds by the dimethylaniline / ultrapure oxygen / cobalt salt system. This system can be used to polymerize high-purity acrylonitrile, methyl methacrylate, ethyl acrylate and styrene. The starting reaction is interpreted as redox catalysis, in which molecular oxygen takes over the roiling of the oxidizing agent. The publication mentioned does not contain any indications of a practical usability of the multicomponent systems under investigation for use in polymerization technology. In fact, even these theoretical papers, which have been accessible to experts for almost 25 years, have not given any impetus for their implementation in practice.

The object of the invention is to develop a new class of activator systems using the previously known knowledge of more component redox systems, which can be used in a novel and simplified manner to trigger polymerization on olefinically unsaturated systems. When oxygen and water are excluded, the new activator systems are said to lead to non-reactive substance mixtures, which in Do not polymerize the mixture with the olefinically unsaturated polymerizable components and are therefore storable, both in the form of single-component systems and in the form of multi-component systems. On the other hand, the new activator systems should have the ability to be activated by the addition of water and oxygen. In preferred embodiments, this activation should already occur at room temperature; if necessary, a moderate temperature increase is provided. A particularly important aspect of the invention is directed to multi-component systems of the type mentioned, which simply by admission of ambient air with their always present moisture and oxygen content at room temperature or only moderately elevated temperatures to trigger the start reaction of a radical polymerization unsaturated systems.

Accordingly, the subject matter of the invention in a first embodiment is to contain free-radically polymerizable nutrient processing tables which can be shaped

if desired, ethylenically unsaturated polymerizable compounds in admixture with soluble and / or insoluble fillers and

an activator system that can be initiated by access to oxygen

the characteristic of the invention is that this multicomponent mixture contains an activator system which can be initiated by the entry of oxygen and water, in particular by the action of ambient air, on the basis of the following main components:

N-alkyl-substituted tert-arylamines with at least one alpha-aliphatic CH bond in the system at least partially soluble metal compounds for accelerating the drying of unsaturated oils and

when moisture enters the free carboxylic acid, hydrolysable compounds of weakly acidic carboxylic acids with pKς values not less than about 0.9.

The essence of the action according to the invention thus lies in the selection of the specific activator system described for the first time in this combination. This system differs from that of L. HORNER et al. described activator systems in particular by the selection of the third component described above. According to the invention, the free carboxylic acid is not present as such, as is the case with the acetic acid investigated by HORNER, rather carboxylic acid derivatives are used which do not have a free carboxyl group as such, but which can be hydrolyzed to form the free carboxylic acid when exposed to moisture. The resulting simplifications and expansions for practice! Work opportunities light up immediately:

The activation state required to initiate the polymerization in the sense of the invention requires the interaction of the aromatic amine and the metal compound which is at least partially soluble in the system with the free carboxylic acid. By introducing the free carboxylic acid not as such, but rather in capped form, an additional degree of freedom is created with regard to the inhibition of the overall system. The complete exclusion of oxygen or. the corresponding removal of oxygen from multi-component mixtures is known not to be practicable within the scope of practical technical action. Starter systems that convert molecular oxygen into a reaction - triggering intermediate stage - or. polymerizable substance mixtures containing such starter systems - are always comparatively due to undesirable side reactions at risk. The possibility according to the invention for additional system inhibition by exclusion of moisture increases the safety in the production, handling, storage and use of the air-sensitive systems. By means of suitable auxiliary measures, which will be described in the following, the degrees of fatigue given here can be increased. This also makes possible, in particular, the one-component production and storage of the polymerizable compositions as a non-reactive 1-component mixture. By simply admitting air at ambient temperature or at most moderately elevated temperatures, the starter system is activated and thus the reaction is triggered in the overall system for dimensionally stable curing. The open period of the system required for the shaping processing can largely be freely determined by further measures of the inventive action described further. Multi-material systems put together according to the invention thus have practical importance in the broadest application-technical sense.

The three main components of the activator system used according to the invention are first described in detail below.

N-alkyl substituted tert-arylamines

All corresponding compounds with at least one alpha-aliphatic CH bond are suitable. The amine components used according to the invention correspond in particular to the following general formula I.

R,

N - R. C D

R. i in which R. denotes an optionally substituted aryl radical, R "has the meaning of R- or else denotes an optionally substituted alkyl radical. This alkyl radical can be straight-chain or branched. R_ denotes a straight-chain or branched alkyl radical, which can also be substituted, is the same as or different from the alkyl radical which may be present in R 1, but is in any case distinguished by the fact that at least one H atom is present in the alpha position to the N.

The preferred aryl radical is the phenyl radical, which in turn can also be substituted, and in particular can be alkyl-substituted. The alkyl radicals present in R 1 and optionally R_ preferably each contain up to about 10, in particular up to about 6, carbon atoms. Corresponding C, radicals and here in particular the methyl radical are of particular importance. In a preferred embodiment, the radicals R ~ and R, corresponding optionally substituted alkyl radicals and the radical R- are an optionally substituted phenyl radical, so that N, N-dialkyl-substituted aniline compounds, which may also be alkylated in the phenyl ring, are generally preferred . The most important components in the sense of the invention are dimethylanium and especially dimethyl-p-toluidine.

Basically apply to the activity or. the activatability of this tert. Amine compounds described by L. HORNER et al. a. a. 0. Laws given: core substituents influence the rate of autoxidation of dimethylanulin. Electron donors increase the autoxidability of the amine, and electrophilic substituents decrease it. Accordingly, p-toluidine compounds are more reactive than the otherwise structurally identical derivative derivatives. The general rules given by HORNER also apply to the alkyl substituents in R, and possibly R-. The methyl group is much easier to oxidize to the hydroperoxide than all other N- Alkyl substituents. In principle, the known results from the action of dibenzoyl peroxide on tertiary amines, as are cited in the cited literature reference, also apply here.

Metal compounds that are at least partially soluble in the system

As already stated, the most important drying substances of the type concerned are characterized in that, above all, metal compounds of such metals. can be used, which can occur in several severity levels. Selected representatives of the transition metals can be particularly active here. The respective selection of the metal can, among other things, have a speed-determining character for initiating polymerization due to a certain temperature dependence of the reactive intervention of this metal component in the overall process. Components that are highly active at room temperature are derived in particular from cobalt and / or manganese. Iron also has a certain - albeit weaker - reaction acceleration in the region of room temperature. Other metal components, for example those based on vanadium, can be increased in their activity by increasing the temperature so that the polymerization reaction can be triggered in the short term.

Cobalt and / or manganese compounds are particularly suitable for working at room temperature, which is particularly advantageous for many fields of application, optionally in admixture with other metallic components such as compounds of lead, cerium, calcium, barium, zinc and / or zirconium. The relevant specialist literature can be referred to here, for example compare the cited publication in "Ullmann" a. O. as well as the pre-literature given there.

The metals affected here are used in the form of such compounds that they are at least partially in the overall system are soluble. Both soap-like metal compounds and other types, in particular complexes bonded to organic residues, are possible. Typical examples of working in the sense of the action according to the invention is the use of corresponding metal naphthenates or metal acetyl acetonates. If there is sufficient solubility of inorganic salts in the system, however, the use of such inorganic systems is also possible. A typical example of this is iron chloride, which has a significantly accelerating effect when used in the system according to the invention.

It may be appropriate to use the metal compounds in each case in a low valence level of the metal - for example as cobalt (I!) Or manganese (I I). In other cases, the use of the metal compound in the higher valence level of the metal is also suitable. For example, iron

3+ chloride preferably used in the form of the Fe salt.

Capped carboxylic acid compound that can be hydrolyzed when exposed to moisture

When selecting these components, the acidity of the free carboxylic acid is of decisive importance. The pK ^ value of the free acid should not be less than about 0.9, the preferred limit is about 1.

If significantly more acidic components are used, the reaction acceleration comes to a standstill. This can be seen in the following examples: The pK ^ value of trichloroacetic acid is approximately 0.6. The addition of trichloroacetic acid in capped or uncapped form to the system destroys the ability of the initiator multicomponent system used according to the invention to trigger polymerization reactions. reactions. In contrast, dichloroacetic acid is a weaker carboxylic acid. Their pK_ value is around 1, 3. This dichloroacetic acid is very well suited for triggering polymerization reactions in the sense of the action according to the invention. Strongly acidic mineral acids, for example hydrochloric acid, also interfere with the ability to initiate polymerization through the activator systems used according to the invention. Acetic acid or derivatives hydrolyzable to acetic acid - pKς value of acetic acid about 4.76 - is excellently suited for accelerated reaction initiation.

The upper limit of the pK ^ value can be seen in the range of very weakly acidic compounds - determined as free carboxylic acid. In terms of numbers, the upper limit is pK _ς values of approximately 13, preferably approximately 11.5. However, carboxylic acids are particularly suitable which, in the hydrolyzed state, have pK_ values of up to about 8, preferably up to about 6 or 7. Particularly effective components of the type concerned here are then derived from carboxylic acids which, in the hydrolyzed state, have pK ^ values in the range from about 1 to 5 or 7.

The carboxylic acids to be used according to the invention in capped form can have one or more carboxyl groups. The constitution of the acid as such - if the correct pK _ς value is exposed - is not so much the decisive parameter. For the practical applicability of the invention, the reliable accessibility of the fully capped form of the respective carboxylic acid is in the foreground of the considerations. In the preferred embodiment of the invention, care is taken to ensure that there are no free carboxyl groups in the feed mixture, but only form during processing by hydrolytic cleavage of the capping part of the molecule. From a preparative point of view, it can accordingly be advantageous to use carboxylic acids with 1 to 4 carboxyl groups and in particular with 1 or 2 carboxyl groups. groups of the component affected here. The use of masked monocarboxylic acids can be particularly simple because the condition for eliminating free carboxyl groups can be set particularly easily here. The selection of the carboxylic acid concerned is largely determined by appropriate considerations of expediency. Easily accessible carboxylic acids such as lower aliphatic carboxylic acids or corresponding aromatic mono- or polyfunctional carboxylic acids are suitable components. Suitable aliphatic carboxylic acids are the C., preferably C, monocarbon

1 -18 ³ 1 -10 acids, the acetic acid in turn being of particular importance. Suitable aromatic carboxylic acids are benzoic acid or corresponding polycarboxylic acids, for example trimellitic or pyromellitic acid. As shown in the example of dichloroacetic acid, substituted acids of this type are also suitable, provided their pK _ς value corresponds to the specified boundary conditions.

An essential core of the teaching according to the invention is to use these weak carboxylic acids in the form of their hydrolysable derivatives. Corresponding derivatives of weakly acidic carboxylic acids of the general formula II are particularly suitable

X - O - CO - R ₄ (II)

in which R _{y is} an optionally substituted alkyl, cycloalkyl or aryl radical and X is a weakly acidic, practically neutral or, at the most, - with simultaneous formation of the free acid R ^ COOH - at at least slightly elevated temperatures by hydrolysis by hydrolysis means very weakly basic residue. This restriction in the definition of the radical X ensures that the weak acid R ^ COOH can actually fulfill the task to be performed by it when the reaction is triggered. Suitable hydrolysable derivatives of the weak Carboxylic acids are, for example, their anhydrides or their mixed anhydrides with other weak carboxylic acids, these other weak carboxylic acids in particular also meeting the pK, -.- limit value conditions specified above. Mixed anhydrides or esters of the weak carboxylic acids defined according to the invention with hydroxyl compounds of such heteroatoms, which after hydrolysis do not lead to any disturbance of the acidity level in the system according to the invention, can be particularly suitable. Particularly suitable here are the mixed anhydrides or esters, described below, with corresponding compounds of boron and / or silicon.

The rate of the course of the reaction can be influenced by the hydrolysis stability of the capped carboxylic acid compound used. Here, reaction-influencing possibilities open up, which make it possible to adapt the polymerization process to the respective application. This is only explained as an example: A masked carboxylic acid compound in the sense of the action according to the invention is acetic anhydride. However, the acceleration of the reaction when the polymer is triggered by molecular oxygen, in particular by the entry of air, is only effected after sufficient hydrolysis by the free acetic acid. Such hydrolysis of the anhydride in situ in the reaction mixture at room temperature and exposure to ambient air with its limited moisture content can be a comparatively lengthy process. On the one hand, this extends the open period of the reactive system, on the other hand, the setting of the reactive system can be unduly delayed in individual cases. If comparatively more hydrolysis-unstable compounds are used instead - for example those of the type described below - then excitation of the Overall system is effective in comparatively short periods of time.

Taking this consideration into account, the following meanings come into consideration for the meaning of the radical X from the general formula I I: radicals of the following general formula I I I

R ₅ - CO - (III)

in which the rest R ,. is identical or different from the radical R _y from the general formula II and in particular means alkyl, cycloalkyl or aryl, it being possible for all these radicals to be substituted with the proviso that the free carboxylic acid R-COOH formed during the hydrolysis is at least as mentioned corresponds to the lower limit for the pK ~ value.

Mixed anhydrides or esters with boron compounds containing hydroxyl groups are suitable as comparatively hydrolysable components. In this class of compounds, the radical X from the general formula I I preferably corresponds to the radical of the general formula IV defined below

In the molecular part according to this general formula IV, the Z radicals can be the same or different and in particular mean a R ..- CO-0 radical and / or alkyl, cycloalkyl and / or aryl radicals which for their part may also be substituted and / or may also be bonded to the boron via an oxygen atom. R-. has the meaning explained in connection with the general formula III, x is 0 or an integer and has in particular the value from 0 to 2. A particularly important masked weak carboxylic acid for the work according to the invention is derived from compounds of the general formula II in which X represents the remainder of the general formula IV, where x is the number 1 and the Z radicals have the meaning of R -CO-0. A characteristic representative of this class of substances is tetraacetoxydiboroxane, which has been shown to be a particularly effective, easily prepared and easily stabilized capped, but nevertheless quickly hydrolyzable by means of ambient air carboxylic acid compound.

Another particularly suitable class of substances of these masked carboxylic acid compounds is derived from analogous compounds of silicon in the X radical. Compounds of this type correspond to the general formula 11, where X has the meaning of the following general formula V.

Z can have the same meaning as given for formula IV, y preferably has a value from 0 to about 10 and in particular a value from 0 to about 5. For preparative reasons, it may be expedient for compounds of this type a portion of the Z radicals is formed by hydrocarbon radicals, in particular by alkyl radicals and here in particular by lower alkyl radicals such as methyl. In a preferred embodiment, in the molecular part of the general formula V there are two alkyl radicals, in particular two, on at least some, preferably on all silicon atoms. Methyl residues. Components of this type are particularly easy to access and are accordingly accessible the associated capped compounds of general formula II are particularly easily accessible.

As compounds of the general formula I I, in which X has the meaning of the general formula IV or V, certain integer components can be present with respect to the index numbers x and y, as has already been stated for the case of tetraacetoxydiboroxane. However, homologous substance mixtures with regard to these radicals IV and in particular with respect to the radical V can also be used, so that x and in particular y as average value do not have to correspond to an integer value.

Activator systems composed of the three main components of aromatic amine compound described here, at least partially soluble metallic drying agent and blocked weak acid capable of hydrolysis are able to initiate all the radically polymerizable olefinically unsaturated systems after absorption of moisture and oxygen from the ambient air which have so far been used with the most diverse, in particular peroxidic starter systems. For the definition of the other constituents of the radically polymerizable multicomponent mixtures which can be shaped and processed according to the invention, reference can be made to the extensive information in the relevant literature which deals with the manufacture and processing of systems which are based on Ba sis olefinically unsaturated compounds which can be polymerized by free radicals are built up, an exceptionally large number of substance systems of this type are available in the professional world today, the properties of which are tailored to the particular intended use. In principle, the principle of triggering the reaction according to the invention by the action of oxygen, in particular by the simple action of ambient air, can be used wherever there is a disruptive interaction with the main components of the process used according to the invention Activator system is excluded. General chemical knowledge, taking into account the above-described laws for the action according to the invention, provides sufficient instructions as to the extent to which specifically selected systems can be utilized or how they must be used in the context of the invention to meet the condition of the action according to the invention to fulfill. This can be seen in the following example:

Polymerizable components and optionally soluble and / or insoluble fillers and mixtures of substances containing the activator systems according to the invention can be designed as a non-reactive 1-component system with the exclusion of air, provided that it is ensured that there are no constituents in the mixture which do little to cause an undesired premature reaction ¬ lead one of the main components of the system according to the invention. It is particularly important for the formation of 1-component systems that the overall systems are free of reactive groups, in particular in the form of reactive hydrogen atoms such as are present, for example, in the form of hydroxyl and / or carboxyl groups. Such reactive groups with active hydrogen atoms interfere whenever they lead to the premature release of the masked weakly acidic carboxylic acids.

However, the presence of such reactive groups in no way makes working with the starter systems according to the invention n ⁿ π-. Here, for example, there is the possibility of - i ^- o ^{^} components "v tem

Overall system mixture components are used, the active hydrogen atoms - z. B. in the form of free carboxyl and / or hydroxyl groups, the multicomponent mixture to be used according to the invention is provided as a multicomponent system in this embodiment. It should be ensured here that the constituents of the mixture with reactive hydrogen atoms in the multicomponent system are separated from the masked weak carboxylic acids of the activator system according to the invention are kept. For practical use of the system, the components are mixed with one another in a manner known per se. The open pot life of the system can be regulated by suitable selection and adaptation of the main components of the activator system, so that here too the triggering of the start reaction and thus ultimately the curing of the system under ambient conditions in the air is possible. This explanation given here by way of example for working with mixture components with contents of reactive hydrogen atoms applies analogously to other reactive components. As long as the activator system remains functional even after all the constituents of the multicomponent mixture have been mixed together, its usability is guaranteed under the specified conditions.

Another way of removing potentially reactive and thus disruptive groups from the reaction is to mask such groups. This working principle - which relates to a further preferred embodiment of the invention - can be understood using the example of undesired free carboxyl groups. Temporary capping with, for example, hydrolysis-unstable groups can ensure that no undesired secondary reactions are triggered during a period of storage with exclusion of moisture. Nevertheless, the capping of such free carboxyl groups can be eliminated again at a later point in time by the influence of moisture - which is required in any case as part of the reaction initiation. It is possible to regulate the stability of the masked shape via the extent of the hydrolysis instability. The general chemical laws apply here in detail. This principle of the hydrolysis-unstable capping of free carboxy groups can also be used in particular in the following combination: Important olefinically unsaturated and radically polymerizable acids of the type of (meth) acrylic acid (s), crotonic acid, maleic acid and the like can be used in this way capped form are added to the reaction mixture and thus the reaction. If the capping of these acid components is more stable to hydrolysis than that of the capped carboxylic acid component of the activator system used according to the invention to trigger the reaction, the unsaturated carboxylic acids are first included in the capped form in the polymerization process. The hydrolytic cleavage of the capping is possible at a later point in time. It is obvious that it is also within the scope of the invention to use such unsaturated carboxylic acids in capped but hydrolytically unstable form at least in part as a weakly acidic catalyst component. Here, for example, acrylic acid or methacrylic acid in the reaction mixture has a double function when the reaction is triggered. After sufficient hydrolytic cleavage of the capping, the free acid formed, in cooperation with the other components of the activator systems according to the invention, triggers the reaction, but at the same time this component is included in the polymerization process and incorporated into the resulting polymer molecule.

In a special embodiment, the invention comprises multicomponent systems which are non-reactive even when air is admitted and which trigger the desired starting reaction only after all the components have been mixed. This can be, in particular, the division of the activator system into a 2-component system. In the preferred embodiment, the tert. N-compound separated from the metal compounds and the hydrolyzable to free carboxylic acids Connections held. Both components of the overall system can, however, contain substantial proportions of the compounds to be polymerized and / or the other fillers and auxiliaries used. In particular, it is possible here to distribute the main amounts of the multicomponent mixture over the two components such that both individual components make up substantial portions of the total mixture. In this way, metering difficulties in the dimensioning and mixing into the ready-to-use mixture can be avoided, as can occur, for example, if a separately kept mixture component in only a very small amount in a very large amount of a second component quickly and reliably should be distributed.

In the preferred embodiment, the multicomponent mixtures of the invention which contain both the activator system according to the invention and the components to be polymerized in admixture with their fillers and / or auxiliaries are in the form of a flowable but at least slightly thickened to pasty, distributable multicomponent mixture. The particular condition is adapted to the application. Adhesives resp. Filling or sealing compounds will generally be more pasty than spreadable or. sprayable paints. In a preferred embodiment, the systems are free from solvents. Their fluidity is usually adjusted or adjusted using ethylenically unsaturated monomers. regulated. The types of monomers predominantly used in free radical polymerization technology are based today on the type of acrylate and / or methacrylate compounds, styrene or substituted styrenes and / or acrylonitrile. The activator systems according to the invention are effective starters for these types of monomers, in particular in the systems customary in practice today, and can be reactive in particular as at room temperature or only slightly elevated temperatures under the influence of ambient air Starter be trained. The polymerization initiation can be used in the full range of the currently known acrylate or methacrylate systems, the styrene-modified substance mixtures, in particular the systems based on unsaturated polyester resins / styrene.

It has been shown that the rapid and effective initiation of polymerization at the system-inherent predetermined point in time is possible in particular if the systems used for the application have at least slightly increased viscosity values. In particular, the polymerization in pure unsaturated monomers stabilized in the usual way, for example in commercially available pure (meth) acrylate, styrene and the like, can cause difficulties. If, however, these components are only slightly thickened, the polymerisation can be successfully achieved by accessing ambient air without difficulty. Preferably, the minimum viscosity of the ^"cured in accordance with the invention, systems in the application state we¬ nigstens about 30 to 100 Pas (Brookfield). It may be useful to work with ieicht higher viscosities in the original state of the processing, so that preferred limits at about 200 mPas and in particular are around at least 300 mPas. In practice, materials whose viscosity values are in the range of at least about 500 are of particular importance in practice, and this applies not only to adhesives and sealants with viscosity values above about 3000 mPas - in particular in the range up to about 10,000 mPas, but also for mixtures of substances for surface coating in the sense of, in particular, solvent-free paint systems. There is generally no need to regulate the minimum viscosity values in the cases relevant for practical use. Only in special cases of the highly mobile liquid phases, as described for example Correspondingly, appropriate measures to slightly thicken the system must be taken into account if the unsaturated monomers are formed. The possibility of designing non-reactive 1-component systems with the exclusion of air access, which react time-controlled under air access, leads to a considerable expansion of the technical possibilities. This is explained using an example: Ready-to-use 1-component adhesives, for example methacrylate-based, which cure by simple exposure to air while triggering polymerization are not known. The only adhesive system that has been developed for this requirement in practice is the cyanoacrylate adhesives, which, however, are distinguished by considerable practical difficulties. The curing reaction of these cyanoacrylates proceeds under the influence of moisture according to an anionic mechanism; the storage stability of such 1-component materials is always at great risk. The performance of cyanoacrylates as an adhesive is limited due to their limited physical properties.

In contrast, the invention allows the compilation of optimized adhesive mixtures based on acrylic and / or methacrylate in the form of a non-reactive 1-component substance mixture which is activated by application to the surfaces to be bonded and the action of the ambient air taking place here and thus becomes adhesive and subsequently hardens. While maintaining the laws of the invention - in particular inert behavior towards the main components of the activator system - soluble and / or insoluble fillers, elasticizers, thickeners, thixotropic agents, pigments, adhesion promoters, stabilizers and the like can be used without the functionality of the actuator system according to the invention is at risk.

A specialty of the multi-substance mixtures according to the invention or. The activator systems used according to the invention in these multi-substance mixtures is that double inhibition and thus double control of the overall system is possible. By With the use of drying agents in the multi-component mixture, stabilization against undesired access to moisture is achieved. The drying agents are preferably incorporated into the multicomponent mixture in predetermined amounts and in active form in a homogeneous distribution. The amount and capacity of the period from which diffusing-in moisture is no longer bound by the desiccant is derived, but instead leads to the hydrolytic cleavage of the blocked weak carboxylic acid with its release. On the other hand, the use of customarily selected reducing agents leads to stabilization against undesired access to oxygen. Here too, the amount of reducing agent used can influence the point in time from which the oxygen activation of the system takes place with the formation of hydroperoxide. It is obvious that this double control option gives considerable freedom in individual cases to influence the course of the reaction. For example, it may be desirable to achieve as complete a saturation as possible of an applied lacquer or adhesive with oxygen without premature barrier formation due to premature polymerization initiation on the surface of the reactive material. In this case, it may be desirable to delay the start reaction by delaying hydrolysis of the blocked acid using a larger amount of the drying agent. Conversely, however, it is also possible to increase the concentration of free acid in the exposed material film by first injecting the oxydate reaction via a comparatively larger amount of reducing agent used, so that one starts immediately when the oxidation reaction starts Larger amounts of free acid are available for the reaction.

A wide variety of mechanisms are available for inhibiting the “Autox” system used according to the invention Available, of which the five basic types 1 to 5 are listed below:

1. Stabilization against 0_, addition of antioxidants

2. Stabilization against H_0, addition of desiccant

3. Stabilization against R-OOH, addition of reducing agent

4. Stabilization against radicals, addition of radical inhibitors

5.Stackabilliissiererung against premature acid formation (H), addition of bases

From the general chemical knowledge, typical stabilizer components are listed below, in each case in brackets after the special compound, which of the five mechanisms listed above is assigned to the stabilizer:

Pyrogallol (1), 0 ₂ -inhibited acrylates (1), hydroquinone (1, 4), hydroquinone monomethyl ether (1, 4), largely dewatered zeolites, in particular water-depleted zeolite A (2), crystal water binding metal salts z. B. anhydrous copper sulfate (2), triphenylphosphine (3), tributylphosphite (3), butylated hydroxytoluene (4), phenothiazine (4), anhydrous basic oxide compounds such as ALO, basic and / or CaO (5), dicyclohexylcarbodiimide (2).

In the multicomponent mixtures of the invention, the activator mixtures preferably make up no more than about 25% by weight and in particular no more than about 10% by weight, in each case based on the weight of the overall system. Depending on the activity of the components used, the weight of the activator mixture can be reduced very sharply and can be reduced, for example, to the range of about 0.1% by weight or at least about 0.5% by weight. Amounts of the activator system of at least about 1% by weight, preferably up to about 8% by weight and particularly from about 1 to 7% by weight, can be particularly suitable. All these Information relates on the one hand to the total weight of the multi-component system according to the invention and the total weight of the three main components of the activator system.

The three main components of the activator system can preferably be used in the following proportions to one another - here% by weight based on the mixture of the three activator components:

5 to 20%, preferably 5 to 15% of the metal compound 30 to 60%, preferably 40 to 55% of the tertiary amine compound

30 to 60%, preferably 40 to 55% of the capped weak acid.

The amounts of metal compounds to be used in each case can also be defined as follows, in particular, via the weight ratio of metal weight to weight of the multicomponent activator system:

Preferred amounts of metal are within the range of 0.01 to 5% by weight, particularly 0.05 to 2% by weight. % and in particular within the range from about 0.1 to 1% by weight of metal, in each case based on the total weight of the activator constituents.

If inhibitors and / or stabilizers of the type specified above are also used to control the course of the reaction and / or the open pot life, their amount is measured according to the stated purpose. In individual cases it can easily be determined by professional considerations and / or by preliminary tests. This is also explained again by way of example using a comparison: if a metal salt which forms water of crystallization, such as copper sulfate, is used for the primary binding of diffusing moisture, then purely in terms of weight, larger amounts are required than with a corresponding one Inhibition of diffusing oxygen by using triphenylphosphine. The regulators used are usually a few percent - z. B. do not exceed about 2 to 5% by weight of the total mixture and are generally below 1% by weight.

In a further embodiment, the subject matter of the invention is the activator systems described in detail at the outset from the three components tertiary amine compound, at least partially soluble metal component and masked compound of the weak acid which can be cleaved by hydrolysis, with pK _ς values of the free acid not less than about 0 , 9th All numerical and factual information relating to the definition of these components also apply analogously in this embodiment of the invention.

The invention further relates to the use of these activator systems for triggering the reaction by the action of oxygen and water, in particular by the action of ambient air, preferably at room temperature or only slightly elevated temperatures of free-radically polymerizable systems containing ethylenically unsaturated components. In this embodiment of the invention, the application of the activator systems in acrylate and / or methacrylate-based polymerizable substances or. Mixtures of substances or comparable systems based on compositions containing styrene and / or acrylonitrile, for example of the type of styrene / unsaturated polyester resin mixtures.

In a particularly important embodiment, the invention relates to aerobically curing adhesive systems, which can be present, in particular, in the form of a 1-component adhesive packaged in storage and are characterized by the use of the activator mixtures according to the invention. Further embodiments of the invention relate to the use of these activator systems in the context of surface coating with polymerizable inserts. special spreadable coating materials. In a preferred embodiment, the invention provides, in a preferred embodiment, spreadable air-drying lacquer systems which are preferably solvent-free. A further embodiment of the invention finally relates to the use of suitable systems, for example the styrene / unsaturated polyester resin systems mentioned, for the production of moldings by triggering a reaction by the action of ambient air.

Systems of the type described above often contain combinations of low molecular weight, ethylenically unsaturated monomers and preformed oligomers and / or polymers which are compatible with the monomers used and in particular are at least partially soluble in them. The content of such multicomponent mixtures of free-radically polymerizable components, in particular their monomer content, is at least about 20% by weight and preferably at least about 40% by weight. Monomer contents can reach the upper limit of 60, 80 or even 90% by weight, taking into account the limiting condition for the at least slightly increased viscosity, in particular the general knowledge of the person skilled in the art applies here. Oligomeric or polymeric components added to the multicomponent mixture can in turn contain reactive groups, in particular ethylenically unsaturated groups, or can also be free thereof. Finally, it is also known that the use of low molecular weight monomer compounds can be practically completely dispensed with if the manageability and in particular the shaping processability of a mixture of substances is ensured which consists exclusively of pre-formed oligomer and / or polymer compounds, which at least partly of the radically triggered poly- ..'.- £. risk or Crosslinking reaction are accessible. Examples

example 1

A mix of

44.5% MMA

45% polyester polyurethane, consisting of

2 mol CAPA 200 (poly-caprolactone from UCC, OHZ 209)

3 moles of 2,4-tolylene diisocyanate (Desmodur T 100, Bayer)

1 mol of B-01/20 (polypropylene glycol monobutyl ether of

Hoechst, OHZ 75)

1 mol hydroxyethyl methacrylate 5% tetraacetoxydiboroxane 5% N, N-dimethyl-p-toluidine 0.5% cobalt naphthenate with a cobalt content of 6%

cures in a layer thickness of about 1 to 2 mm in air within 60 minutes. By reducing the layer thickness to the usual film thickness for bonding, the curing time drops to 20 minutes.

Example 2

The adhesive mixture consists of

49.5 wt% MMA

40% by weight soluble filler (Plexigum MB 319, Röhm)

% By weight of tetraacetoxydiboroxane

5% by weight of N, N-dimethyl-p-toluidine

0.5% by weight cobalt naphthenate The multicomponent mixture is produced from anhydrous components and, after degassing, is stored in an inert gas atmosphere.

For the bonding, the adhesive mixture is applied to the surfaces to be bonded and exposed to the ambient air for 3 to 5 minutes. After the start of the reaction - ascertainable by clouding and beginning skin formation - the parts to be joined are glued and fixed.

After storage for 24 hours at room temperature, material breakage results for the bonding of PVC sheets in tensile shear strength tests.

Examples 3 to 8

Mixtures of

harden on contact with the ambient air. For gluing, the parts to be glued are thinly coated and joined after 3 to 5 minutes (skin formation) and fixed if necessary. Tensile shear strengths were determined after 24 hours. Example carboxylic acid derivative Pot life tensile shear strength no. (Min) (PVC)

(N / mm ² )

Tetraacetoxydiboroxan 60 7.9 (MB)

Tetraacetoxydiboroxan 60 6.5 (MB)

Addition of 200 ppm triphenylphosphine

Trimethyl acetate 150 3.0 (MB) silylester

Propionic acid trimethyl 180 silylester

Tetraacetoxysilane 15 10.5 (MB)

Tri- methacrylic acid 64 1.5 methylsilyl ester

MB = broken material

Example 9

A mixture of

62% tetrahydrofurfuryl methacrylate 31% Plexigum MB 319 0.03% co-acetylacetonate 3.5%, N-dimethyl-p-toluidine 3.5% tetraacetoxydiboroxane has a pot life of 60 minutes when in contact with the ambient air.

Bondings carried out according to Examples 4 to 9 resulted in

2 2

Z tensile strength of 7.5 N / mm on PVC and 7.6 N / mm on

Iron.

Example 10

A mixture of

polymerizes 15 minutes after contact with the atmosphere.

Example 11

The commercial product "Diacryl 101" (dimethacrylate of bisphenol A x 2 EO) is used in an amount of 89.5% by weight with an activator system composed of 5% by weight dimethyl-p without the use of further reactive monomer components toluidine, 5% by weight of tetraacetoxy diboroxane and 0.5% by weight of cobalt naphthenate solution.

After exposure of this mixture of substances to the air, the material is polymerized within 1 hour (surface stickiness) and hardens within a day.

An analogous behavior can be seen when using cyclohexyl methacrylate.

Claims

Patent claims

1 . Containing radically polymerizable multicomponent mixtures that can be shaped

if desired, ethylenically unsaturated polymerizable compounds in admixture with soluble and / or insoluble fillers and / or other auxiliaries and

an activator system which can be initiated by the entry of oxygen,

characterized in that they contain an activator system which can be initiated by the entry of oxygen and water, in particular by the action of ambient air, on the basis of the following main components:

N-Alkyl-substituted tert-arylamines with at least one alpha-aliphatic CH bond

Metal compounds which are at least partially soluble in the system for accelerating the drying of unsaturated oils and

when moisture is added to the free carboxylic acid, hydrolysable compounds of weakly acidic carboxylic acids with pK. values not less than about 0.9.

2. Multi-component mixtures according to claim 1, characterized gekennzeich¬ net that they are designed as a non-reactive 1-component system with exclusion of air or as a non-reactive multi-component system with air access, with 2-component systems in particular as multi-component systems exist in which the tert. N connection separated from the Metal compounds and the compounds hydrolyzable to free carboxylic acids is kept.

3. Multi-component mixtures according to claims 1 and 2, characterized ge indicates that they are free of reactive groups, in particular reactive hydrogen atoms, for example in the form of OH and especially when they are designed as a non-reactive 1-component system / or -COOH groups, which lead to the premature release of the weakly acidic carboxylic acids.

4. Mehrstoffgemtsche according to claims 1 to 3, characterized ge indicates that they are designed as a system at ambient temperature or only moderately elevated temperatures by access to ambient air.

5. Multi-component mixtures according to claims 1 to 4, characterized in that they are flowable, preferably at least slightly thickened, spreadable to pasty, distributable material! are trained.

6. More mixtures according to claims 1 to 5, characterized in that they are compounds of the general formula I as N-alkyl-substituted arylamines

R,

\ NUMBER 1 )

^R 2 ^"

included in the

R, an optionally substituted aryl radical, in particular an optionally alkyl-substituted phenyl radical. R_ has the meaning of R. or an optionally substituted straight-chain or branched alkyl radical and

R represents a straight-chain or branched alkyl radical, which can also be substituted, but which, in the alpha position relative to the N, has at least one H atom.

7. Multi-component mixtures according to Claims 1 to 6, characterized in that the compounds of the general formula I in the aromatic ring contain substituted or unsubstituted dialkylaniline compounds, the alkyl radicals of which are each preferably up to 10, in particular up to 6, carbon atoms, where optionally ring-alkyl-substituted aniline derivatives, in particular those having the structure of dimethylaniline and / or of dimethyl p-toluidine, are particularly suitable.

8. Multi-component mixtures according to claims 1 to 7, characterized ge indicates that they contain compounds of metals which occur in several valency levels, in particular compounds of corresponding transition metals, as the at least partially soluble, metal-containing dry substances, preferably the transition metals Metal ions are each present in their low valence level.

9. Multi-component mixtures according to claims 1 to 8, characterized ge indicates that they are soluble in organic media metal compounds of cobalt and / or manganese or also ddeess EEiisseennss eenntthhaalltteenn ,, wwoobbeeii ddaas iron can also be used as an Fe compound can.

1 0. Multi-component mixtures according to claims 1 to 9, characterized ge indicates that they do not hydrolyzable compounds of carboxylic acids with pK ^ values when exposed to moisture less than about 1, preferably not less than about 1.3.

11. Multi-component mixtures according to Claims 1 to 10, characterized in that they contain capped compounds which are hydrolyzable in the presence of moisture and have an upper limit of the pK _ς value of about 13, preferably of about 11, 5 and in particular corresponding carboxylic acid compounds with an upper limit of the pK _ς - Free carboxylic acid value of about 7 included.

12. Multi-component mixtures according to claims 1 to 11, characterized in that they contain blocked carboxylic acids with one or more carboxyl groups, in particular with 1 to 4 carboxyl groups.

13. Multi-component mixtures according to Claims 1 to 12, characterized in that they contain the weak carboxylic acids in the form of their anhydrides and / or as mixed A.r.hydrides with other weak carboxylic acids and / or as mixed anhydrides or. Contain esters with hydroxyl compounds of hetero atoms, in particular corresponding compounds of boron and / or silicon.

14. Multi-component mixtures according to claims 1 to 13, characterized in that they are hydrolysis-labile derivatives of weakly acidic carboxylic acids of the general formula I I

X - O - CO - R ₄ (II)

included in the

R _{ü represents} an optionally substituted alkyl, cycloalkyl or aryl radical and X is a - with simultaneous formation of the free acid R _y COOH - at least slightly elevated temperatures by hydrolysis, weakly acidic, practically neutral or at most very weakly basic radical.

15. Multi-component mixtures according to Claims 1 to 14, characterized in that they contain hydrolysis-labile derivatives of the general formula I I in which X represents the rest of the general formula IV

. B-K-B) - (IV)

means, in this formula the radicals Z are identical or different and have the following meaning:

a residue R ,. - CO - 0 -, where R .. is the same or different from the radical R from the general formula II and in particular means alkyl, cycloalkyl or aryl, where these radicals can also be substituted with the proviso that those in the hydrolysis resulting free carboxylic acid R _j - COOH corresponds at least to the lower limit mentioned for the pK -.- value

and / or Z denotes alkyl, cycloalkyl and / or aryl radicals, which in turn may also be substituted and / or bonded to the boron via an oxygen atom,

x is a number from 0 to 2 and in particular has the meaning of 1.

16. Multi-component mixtures according to Claims 1 to 13, characterized in that they contain compounds of the general formula I I in which X is a radical of the general formula V.

where Z has the meaning given for compounds of the general formula IV and y has a value from 0 to about 10 and in particular a value up to about 5.

17. Multi-component mixtures according to Claims 1 to 16, characterized in that they contain, as ethylenically unsaturated polymerizable components, acrylate and / or methacrylate compounds or systems, styrene or styrene derivatives and / or acrylonitrile, which also entirely or partly in the form of reactive preformed oligomer and / or polymer compounds.

1 8. Multi-substance mixtures according to claims 1 to 17, characterized ge indicates that they additionally contain soluble and / or insoluble fillers, thickeners, elastifying agents, pigments, adhesion promoters, stabilizers and the like in the system.

19. Mixtures of active substances according to claims 1 to 18, characterized in that they contain drying agents in active form for stabilizing against undesired access to moisture and / or reducing agents for stabilizing against undesired access to oxygen.

20. Multi-component mixtures according to claims 1 to 19, characterized in that the activator mixture makes up no more than about 25% by weight, preferably not more than 10% by weight of the overall system, and preferably at least 0.1% by weight. % and in particular about 1 to 8% by weight of the total system.

21. Multi-component mixtures according to claims 1 to 20, characterized in that the components of the activator system are used in approximately the following proportions to one another -% by weight, based on the mixture of the three activator components:

5 to 20, preferably 5 to 15% metal compound or 0.01 to 5, preferably 0.05 to 2% by weight metal 30 to 60, preferably 40 to 55% tert. Amine compound 30 to 60, preferably 40 to 55% of the blocked weak acid.

22. Multi-component mixtures according to Claims 1 to 21, characterized in that their content of free-radically polymerizable components, in particular their monomer content, is at least about 20% by weight and preferably at least about 40% by weight.

23. Multi-component mixtures according to claims 1 to 22, characterized in that in the application form they have a minimum viscosity of about 30 mPas, preferably of at least about 100 mPas and in particular of at least about 300 mPas (Brookfield).

24. Use of the multicomponent mixtures according to claims 1 to 23 as an aerobically curing adhesive system, in particular in the form of a 1-component adhesive packed in a storage-stable manner.

25. Use of the active ingredient mixtures according to Claims 1 to 23 for surface coating, in particular as a brushable air-drying lacquer system or for the formation of plastic molded parts.