DE102022127933A1 - Radical polymerization of UV-curing silane acrylates in an isocyanate-containing polyurethane matrix - Google Patents

Abstract

The present invention relates to a process for producing a polymer composition in which a silane-modified polymer is polymerized by radical chain polymerization with an ethylenically unsaturated monomer and another ethylenically unsaturated polymer which has a radical photoinitiator group in a polyol or in a prepolymer with terminal isocyanate groups, and to a polymer composition produced by this process. The invention further relates to a process for producing a moisture-curing polyurethane hot melt adhesive composition, a 1K polyurethane adhesive and a 2K polyurethane adhesive based on the polymer composition according to the invention. The invention further relates to the moisture-curing polyurethane hot melt adhesive composition produced by the processes, the 1K polyurethane adhesive and the 2K polyurethane adhesive.

Description

The present invention relates to a process for producing a polymer composition in which a silane-modified polymer is polymerized by radical chain polymerization with an ethylenically unsaturated monomer and another ethylenically unsaturated polymer which has a radical photoinitiator group in a polyol or in a prepolymer with terminal isocyanate groups, and to a polymer composition produced by this process. The invention further relates to a process for producing a moisture-curing polyurethane hot melt adhesive composition, a 1K polyurethane adhesive and a 2K polyurethane adhesive, based on the polymer composition according to the invention together with the moisture-curing polyurethane hot melt adhesive composition produced therewith, the 1K polyurethane adhesive and the 2K polyurethane adhesive.

Background of the invention

Depending on the application, adhesives require a long open time, for example, because joining is often done manually. At the same time, a rapid build-up of strength is required after joining, because the parts to be joined must be processed further as quickly as possible. This contradictory property profile is solved in polyurethane adhesives, for example, by using an acrylate polymer in powder form in a polyether-based polyurethane. The latter enables a long open time, while the acrylate polymer ensures a high initial tack. Incorporating the acrylates is often problematic because they introduce a lot of air and are difficult to dissolve. This can be solved by polymerizing the acrylate polymers directly in a polyol, which is then converted to polyurethane. This process also enables the use of acrylate polymers whose glass transition temperature is below room temperature. Furthermore, these can be modified as desired with co-monomers. The properties of the adhesives are limited, however, because the acrylate polymer is a thermoplastic that softens at higher temperatures or sometimes has a lower resistance to certain chemicals.

In summary, the resistance of reactive adhesives to temperature and certain chemicals is reduced by the use of thermoplastic materials such as acrylate polymers. In addition, bonding of inorganic materials without surface treatment with polyurethane adhesives leads to adhesion problems.

The US 5,021,507 A concerns acrylic-modified reactive urethanes and teaches in column 2, lines 58 to 68 that in the case of ethylenically unsaturated monomers with moisture reactive functional groups, it is necessary that the monomers are added only after the formation of the prepolymer and only then polymerize by means of radical polymerization.

Further state of the art can be found in US$5,018,337 , the WO 2016/123418 A1 or the WO 01/81495 A2 be taken.

The present invention is based on the PCT/ EP2022/060648 of the applicant, which concerns the polymerization of a silane-modified polymer formed by radical chain polymerization in a polyol or in a prepolymer with terminal isocyanate groups, which is then used in polyurethane formulations. By using polysilane acrylates in the polyurethane adhesive, the viscosity is reduced depending on the silane content and thus also the initial strength. In contrast, the system achieves the opposite effect in terms of final strength. Moisture crosslinking in a polyurethane adhesive occurs primarily via the reaction of the isocyanate groups and secondarily via the silane groups and thus leads to longer pressing times for bonds, which can be a disadvantage depending on the application.

The present invention is based on the object of improving the state of the art or offering an alternative.

Summary of the invention

According to a first aspect of the present invention, the stated object is achieved by a process for producing a polymer composition according to claim 1. Further embodiments are the subject of the further independent and dependent claims.

1. a) Kombinieren von:
   1. (i) einem Polyol oder einem Prepolymer mit endständigen Isocyanat (NCO)-Gruppen mit
   2. (ii) einem ethylenisch ungesättigten, keinen aktiven Wasserstoff enthaltenden Monomer, das keine feuchtigkeitsreaktiven funktionellen Gruppen aufweist (Monomertyp A), und
   3. (iii) einem ethylenisch ungesättigten, keinen aktiven Wasserstoff enthaltenden Monomer, das eine feuchtigkeitsreaktive funktionelle Gruppe aufweist (Monomertyp B);
   4. (iv) einem ethylenisch ungesättigten, keinen aktiven Wasserstoff enthaltenden Monomer, das eine radikalische Photoinitiator-Gruppe aufweist (Monomertyp C);
2. b) Polymerisieren der Mischung aus Schritt a) unter Anwendung eines Radikalpolymerisationsverfahren mit einem Kettenübertragungsmittel zur Erzielung eines niedrigmolekularen Polymers;
3. c) optionale Erwärmung der Mischung aus Schritt b) auf eine Temperatur von 100°C bis 160°C für 10 bis 60 Minuten zur teilweisen Vernetzung des Polyols oder des Prepolymers mit endständigen NCO-Gruppen mit dem niedrigmolekularen Polymer.

In a first aspect, the invention relates to a process for producing a polymer composition, the process comprising the following steps:

1. a) Combining:
   1. (i) a polyol or a prepolymer having terminal isocyanate (NCO) groups with
   2. (ii) an ethylenically unsaturated monomer containing no active hydrogen and having no moisture-reactive functional groups (monomer type A), and
   3. (iii) an ethylenically unsaturated monomer containing no active hydrogen and having a moisture-reactive functional group (monomer type B);
   4. (iv) an ethylenically unsaturated monomer containing no active hydrogen and having a radical photoinitiator group (monomer type C);
2. b) polymerizing the mixture from step a) using a free radical polymerization process with a chain transfer agent to obtain a low molecular weight polymer;
3. c) optionally heating the mixture from step b) to a temperature of 100°C to 160°C for 10 to 60 minutes to partially crosslink the polyol or the prepolymer with terminal NCO groups with the low molecular weight polymer.

The following terminology is used to explain this:

The ethylenically unsaturated group allows the radical polymerization of the monomers to form a polymer. The absence of active hydrogen in the monomers ensures that the monomers do not participate in the subsequent addition reaction to form the polyurethane. Monomer type A contributes to the construction of the polymer chain, while monomer type B allows a reaction with the polyol or the isocyanate groups of the prepolymer, with the moisture-reactive groups of the polymer or in the application, such as with inorganic substrates to improve adhesion to these substrates.

The monomer type C introduces a photoreactive group into the polymer, which enables curing using UV radiation. In the present invention, moisture crosslinking via silane or isocyanate groups is combined with rapid UV crosslinking via radical polymerization. This is a so-called "UV moisture dual cure" system. In the strict sense, it is even a "triple cure system" because three crosslinkings are used: primary via UV crosslinking, secondary via the reaction of the isocyanate groups and tertiary via the silane groups.

The "UV-moisture-dual-cure" systems of the present invention primarily offer the advantage of UV-curing of UV-active groups and secondarily via the moisture-crosslinking groups. This makes it possible to generate a particularly rapid initial strength using UV light with low-viscosity adhesives, for example in order to significantly shorten the process times in surface lamination. In the case of transparent materials such as transparent films, subsequent crosslinking using UV light is also possible after surface lamination.

The polymer according to the invention produced by means of monomers with ethylenically unsaturated groups, which is preferably an acrylate polymer, is also referred to below as ethylene-based polymer.

By modifying the ethylene-based polymer, which is preferably an acrylate polymer, with silanes, these can react with moisture after application and are thereby cross-linked. This leads to an increase in resistance to heat and certain chemicals. In addition, silanes react with inorganic materials, such as glass or metal, and thereby increase the bond to them. This also expands the area of application of these adhesives. Under the influence of additional heat, cross-linking can be accelerated and a permanently tacky adhesive polymer film is formed. In addition, it is also possible to produce reactive adhesives that do not contain any monomeric isocyanates and are therefore not subject to labeling. This enables the adhesives to be handled safely and does not require any complex measures when used.

The polymers can be used for adhesives, sealants and coatings, reactive hot melt adhesives, textile adhesives, adhesives for the wood and furniture sector, automotive adhesives, adhesives in the construction sector, liquid 1-component adhesives, sealants, primers and coatings.

• • Erhöhung der Temperaturbeständigkeit durch die Vernetzung der Silane.
• • Eine Reaktion der Silane mit anorganischen Substraten, um die Adhäsion auf diesen zu verbessern.
• • Mögliche Herstellung von Produkten mit Isocyanat-Monomerkonzentrationen unter 0.1 %, welche dadurch kennzeichnungsfrei sind.
• • eine besonders schnelle, durch UV-Licht steuerbare, Anfangsfestigkeit.

The technical concept of the invention is based on the modification of ethylene-based polymers and in particular acrylate polymers with silanes in order to improve the property profile. Possible improvements can be as follows:

• • Increase in temperature resistance through cross-linking of the silanes.
• • A reaction of the silanes with inorganic substrates to improve adhesion to them.
• • Possible production of products with isocyanate monomer concentrations below 0.1%, which are therefore exempt from labelling.
• • a particularly fast initial strength that can be controlled by UV light.

The invention has several advantages over the prior art. Thermoplastic acrylate polymers are converted into reactive polymers that react with moisture to form thermosets and thus have greater resistance to heat and specific chemicals. Since the silane groups are distributed randomly across the polymer and not just at the end, as is the case with polyaddition products or subsequent silanization, the crosslinking density and thus the resistance of the material is increased. Silanes also offer the possibility of reacting with inorganic materials such as glass or metals in order to increase the bond strength to these materials, which expands the adhesion spectrum or enables the bonding of inorganic materials with organic materials such as plastics. There are also three synthesis routes that also enable the production of materials without isocyanate monomers. This means that these products do not require labeling and are not subject to any restrictions.

• • Herstellung eines silanmodifizierten Ethylen-basierten Polymers (bevorzugt als Acrylatpolymer) in einem Polyol oder in einem Prepolymer mit endständigen NCO-Gruppen, mit anschließender Umsetzung des Polyols oder des Prepolymers mit endständigen NCO-Gruppen zu einem thermoplastischen Polyurethan.
• • Herstellung eines silanmodifizierten Ethylen-basierten Polymers (bevorzugt als Acrylatpolymer) in einem Polyol oder in einem Prepolymer mit endständigen NCO-Gruppen, mit anschließender Umsetzung des Polyols oder des Prepolymers mit endständigen NCO-Gruppen zu einem reaktiven Polyurethan.
• • Herstellung eines silanmodifizierten Ethylen-basierten Polymers (bevorzugt als Acrylatpolymer) in einem Polyol oder in einem Prepolymer mit endständigen NCO-Gruppen, mit anschließender Umsetzung des Polyols oder des Prepolymers mit endständigen NCO-Gruppen zu einem reaktiven Polyurethan, welches daraufhin mit Aminosilanen oder Mercaptosilanen zu einem silanterminiertem Polyurethan umgesetzt wird.

The present polymer composition can be used as a novel intermediate product for the production of various polyurethanes. In particular, the following possibilities arise:

• • Preparation of a silane-modified ethylene-based polymer (preferably as an acrylate polymer) in a polyol or in a prepolymer with terminal NCO groups, with subsequent conversion of the polyol or the prepolymer with terminal NCO groups to a thermoplastic polyurethane.
• • Preparation of a silane-modified ethylene-based polymer (preferably as an acrylate polymer) in a polyol or in a prepolymer with terminal NCO groups, followed by conversion of the polyol or the prepolymer with terminal NCO groups to a reactive polyurethane.
• • Preparation of a silane-modified ethylene-based polymer (preferably as an acrylate polymer) in a polyol or in a prepolymer with terminal NCO groups, with subsequent conversion of the polyol or the prepolymer with terminal NCO groups to a reactive polyurethane, which is then converted with aminosilanes or mercaptosilanes to a silane-terminated polyurethane.

The invention in detail

The polymerization of monomer type A with monomer types B and C according to the invention is generally carried out by bringing all the monomers together into the reaction vessel and allowing them to react randomly according to their relative concentrations and relative reactivity, so that random polymers are formed. However, to increase or reduce the non-uniformity of the polymers, one or more of the ethylenically unsaturated monomers can also be added during the polymerization.

It is conceivable that the monomers according to monomer type A to monomer type C are added stepwise, so that the radical polymerization is started after adding a defined mixture of monomer type A to monomer type C and only after polymer formation, which is accompanied by an almost complete consumption of the monomers, is a defined mixture of monomer type A to monomer type C added to the reaction mixture again. A stepwise addition prevents overheating of the reaction mixture due to the exothermic polymerization reaction.

The radical polymerization process is preferably carried out at a temperature of less than 100°C, more preferably at a temperature of 40 to 95°C and particularly preferably at a temperature of 80 to 90°C.

It is preferred if the weight ratio of monomer type A to monomer type C defined in the first step is also maintained in the second addition.

It is also conceivable that the amount of monomer type A in the second step is greater than the amount of monomer type A in the first addition. Preferably, the ratio of monomer type A _{first addition} to monomer type A _{second addition} is between 1:1 and 1:10, further preferably between 1:2 and 1:8 and in particular between 1:3 and 1:7.

Accordingly, it is conceivable that the amount of monomer type B in the second step is greater than the amount of monomer type B in the first addition. Preferably, the ratio of monomer type B _{first addition} to monomer type B _{second addition} is between 1:1 and 1:10, more preferably between 1:2 and 1:8 and in particular between 1:35 and 1:7.

Accordingly, it is conceivable that the amount of monomer type C in the second step is greater than the amount of monomer type C in the first addition. Preferably, the ratio of monomer type C in _{the first addition} to monomer type C in the _{second addition} is between 1:1 and 1:10, more preferably between 1:2 and 1:8 and in particular between 1:35 and 1:7.

In the optional step (c) of the process, the mixture from step b) containing the low molecular weight polymer as a result of the radical polymerization is heated to such an extent that the polyol or the prepolymer with terminal NCO groups is partially crosslinked with the low molecular weight polymer. The low molecular weight polymer can react with the hydroxyl groups of the polyol or the isocyanate groups of the prepolymer due to its moisture-reactive groups. This reaction leads to a polymer composition with increased temperature resistance.

In the optional step (c), the silane groups can alternatively or additionally react with each other. This reaction also leads to a polymer composition with increased temperature resistance.

According to the invention, a polyol or a prepolymer with terminal NCO groups is used in the process for producing the polymer composition.

With regard to the polyol, this is to be understood as meaning that at least one polyol can be used here, i.e. two, three, four or even more polyols. Preferably, exactly one polyol is used in the process.

Advantageously, the polyol used in the process according to the invention has a water content of not more than 0.1% by weight and preferably not more than 0.05% by weight.

Suitable polyols are selected from the group consisting of polyester, polyether polyols such as polyethylene oxide or polypropylene oxide, hydroxyl group-containing polycaprolactone, polyoxyalkylene polyol (synonymous with the term “polyglycol”), monosubstituted glycol ester, polythioether, polyamide, polyesteramide, polycarbonate, polyacetal, polyhydrocarbon polyol, polyacrylate polyol, polymethacrylate polyol, polyalcohol, bisphenol, polycarbonate polyol, polyhydroxy-functional fats and oils and mixtures thereof.

Polyether polyols such as diols with a molecular weight of 400 to 4000 g/mol or polypropylene glycol are particularly suitable.

Suitable polyols are, on the one hand, the high molecular weight polyoxyalkylene polyols already mentioned, preferably polyethylene oxides or polyoxypropylene diols with a degree of unsaturation lower than 0.02 mEq/g and with a molecular weight in the range from 400 to 18,000 g/mol, in particular those with a molecular weight in the range from 1,000 to 4,000 g/mol. PPG 2000 or PPG 4000 are particularly suitable.

To achieve a higher cross-linking density, higher-value alcohols such as triols and tetraols can also be used. Examples of these are glycerin, trimethylolpropane or pentaerythritol.

Polyoxyalkylene polyols, also called polyether polyols, polyglycols or oligoetherols, are also suitable. These are polymerization products of ethylene oxide, 1,2-propylene oxide, 1,2- or 2,3-butylene oxide, oxetane, tetrahydrofuran or mixtures thereof, possibly polymerized with the aid of a starter molecule with two or more active hydrogen atoms such as water, ammonia or compounds with one or more OH or NH groups such as 1,2-ethanediol, 1,2- and 1,3-propanediol, neopentyl glycol, diethylene glycol, triethylene glycol, the isomeric dipropylene glycols and tripropylene glycols, the isomeric butanediols, pentanediols, hexanediols, heptanediols, octanediols, nonanediols, decanediols, undecanediols, 1,3- and 1,4-cyclohexanedimethanol, bisphenol A, hydrogenated bisphenol A, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, glycerin, aniline, and mixtures of the aforementioned compounds.

Particularly suitable polyester polyols are those which are produced from di- to trihydric, in particular dihydric, alcohols, such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-hexanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, 1,12-hydroxystearyl alcohol, 1,4-cyclohexanedimethanol, dimer fatty acid diol (dimer diol), hydroxypivalic acid neopentyl glycol ester, glycerin, 1,1,1-trimethylolpropane or mixtures of the aforementioned alcohols, with organic di- or tricarboxylic acids, in particular dicarboxylic acids, or their anhydrides or esters, such as succinic acid, glutaric acid, adipic acid, Trimethyladipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic acid, fumaric acid, dimer fatty acid, phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, dimethyl terephthalate, hexahydrophthalic acid, trimellitic acid and trimellitic anhydride, or mixtures of the aforementioned acids, as well as polyester polyols made from lactones such as ε-caprolactone and starters such as the aforementioned di- or trihydric alcohols.

It is also conceivable to use polycarbonate polyols, which can be obtained by reacting, for example, the above-mentioned alcohols used to form the polyester polyols with dialkyl carbonates, diaryl carbonates or phosgene.

Also suitable are polyhydroxy-functional fats and oils, for example natural fats and oils, in particular castor oil; or polyols obtained by chemical modification of natural fats and oils - so-called oleochemical - such as the epoxy polyesters or epoxy polyethers obtained by epoxidation of unsaturated oils and subsequent ring opening with carboxylic acids or alcohols, or polyols obtained by hydroformylation and hydrogenation of unsaturated oils; or polyols obtained from natural fats and oils by degradation processes such as alcoholysis or ozonolysis and subsequent chemical linking, for example by transesterification or dimerization, of the degradation products obtained in this way or derivatives thereof. Suitable degradation products of natural fats and oils are in particular fatty acids and fatty alcohols as well as fatty acid esters, in particular methyl esters (FAME), which can be derivatized to hydroxy fatty acid esters, for example by hydroformylation and hydrogenation.

It is also conceivable to use polyhydrocarbon polyols. These are also called oligohydrocarbonols and include, for example, polyhydroxy-functional polyolefins, polyisobutylenes, polyisoprenes; polyhydroxy-functional ethylene-propylene, ethylene-butylene or ethylene-propylene-diene copolymers, such as those produced by Kraton Polymers, for example; polyhydroxy-functional polymers of dienes, in particular of 1,3-butadiene, which can also be produced in particular from anionic polymerization; polyhydroxy-functional copolymers of dienes such as 1,3-butadiene or diene mixtures and vinyl monomers such as styrene, acrylonitrile, vinyl chloride, vinyl acetate, vinyl alcohol, isobutylene and isoprene, for example polyhydroxy-functional acrylonitrile/butadiene copolymers, such as those obtained from epoxides or amino alcohols and carboxyl-terminated acrylonitrile/butadiene copolymers, as well as hydrogenated polyhydroxy-functional polymers or copolymers of dienes.

In addition to these polyols, small amounts of low molecular weight di- or polyhydric alcohols such as 1,2-ethanediol, 1,2- and 1,3-propanediol, neopentyl glycol, diethylene glycol, triethylene glycol, the isomeric dipropylene glycols and tripropylene glycols, the isomeric butanediols, pentanediols, hexanediols, heptanediols, octanediols, nonanediols, decanediols, undecanediols, 1,3- and 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, dimeric fatty alcohols, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, glycerin, pentaerythritol, sugar alcohols such as xylitol, sorbitol or mannitol, sugars such as sucrose, other higher-value alcohols, low molecular weight alkoxylation products of the aforementioned di- and polyhydric alcohols, as well as Mixtures of the aforementioned alcohols are used in the production of the polyurethane polymer containing isocyanate groups.

It is also conceivable that, in addition to these polyols, small amounts of low molecular weight di- or polyhydric amines such as ethylenediamine, toluenediamine (TDA), diaminodiphenylmethane (DADPM) and polymethylene polyphenyleneamine; or also amino alcohols such as ethanolamine and diethanolamine, as well as mixtures of the aforementioned amines and amino alcohols can be used in the production of the polyurethane polymer containing isocyanate groups.

In the process for producing the polymer composition, a prepolymer with terminal NCO groups can also be used. This is to be understood as meaning that at least one corresponding prepolymer can be used here, i.e. also two, three, four or even more prepolymers. Preferably, exactly one prepolymer with terminal NCO groups is used in the process.

According to one advantage, it can be provided that the prepolymer with terminal NCO groups has a molar ratio of NCO to OH groups of between 1.5 to 1 and 2.0 to 1.

In one embodiment, the NCO-terminated prepolymer is prepared by reacting a diol with diisocyanate.

Suitable polyols are selected from the group consisting of polyester, hydroxyl group-containing polycaprolactone, polyglycols, monosubstituted glycol esters, polythioethers, polyamide, polyesteramide, polycarbonate, polyacetal, polyhydrocarbon polyol, polyacrylate polyol, polymethacrylate polyol, polyalcohol, bisphenol, polycarbonate polyol, polyhydroxyfunctional fats and oils and mixtures thereof.

Diols, polyethylene oxides or polypropylene oxides are particularly suitable.

Suitable polyols are, on the one hand, the high molecular weight polyglycols already mentioned, preferably polyethylene oxides or polyoxypropylene diols with a degree of unsaturation lower than 0.02 mEq/g and with a molecular weight in the range from 400 to 18,000 g/mol, in particular those with a molecular weight in the range from 1,000 to 4,000 g/mol. PPG 2000 or PPG 4000 are particularly suitable.

A mixture of polyols can also be used. This is advantageously a mixture of two or more polyethylene oxides or a mixture of two or more polyoxypropylene diols. A mixture of PPG1000 and PPG 400 is particularly advantageous.

For the preparation of the prepolymer with terminal isocyanate groups, the diisocyanates familiar to the person skilled in the art for the production of polyurethane polymers can be used.

It may further be possible that the diisocyanate for this prepolymer synthesis is selected from the group consisting of ethylene diisocyanate, ethylidene diisocyanate, propylene diisocyanate, butylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, cyclopentylene-1,3-diisocyanate, cyclohexylene-1,4-diisocyanate, cyclohexylene-1,2-diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diisocyanatodicyclohexylmethane, 2,2-diphenylpropane-4,4'-diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, xylylene diisocyanate, 1,4-naphthylene diisocyanate, 1,5-naphthylene diisocyanate, diphenyl-4,4'-diisocyanate, Azobenzene-4,4'-diisocyanate, diphenylsulfone-4,4'-diisocyanate, dichlorohexamethylene diisocyanate, furfurylidene diisocyanate, 1-chlorobenzene-2,4-diisocyanate, 1,3-bis(isocyanatomethyl)benzene, 1,3-bis(isocyanatomethyl)cyclohexane, block diisocyanates and carbodiimide-modified diisocyanates, as well as any mixtures of the aforementioned diisocyanates. Diphenylmethane diisocyanates are preferably used here, and 4,4'-diphenylmethane diisocyanate (4,4'-MDI) is particularly preferred.

In the radical polymerization process, an initiator can be used which is a peroxide initiator or an azo initiator. Preferred initiators are dilauroyl peroxide, dibenzoyl peroxide, dimethyl 2,2'-azobisisobutyrate, di-(4-tert-butyl-cyclohexyl)-peroxydicarbonate and azobis(isobutyronitrile). The use of dilauroyl peroxide is preferred.

During the photoreaction, monomer type A can serve as a co-initiator of UV curing through radical formation due to hydrogen radical abstraction. Tertiary amines or mercapto compounds can serve as additional co-initiators.

It is also conceivable that an auxiliary substance and/or an additive is added to the reaction mixture in the process according to the invention. Examples include surface-active substances, Fillers, other flame retardants, nucleating agents, oxidation stabilizers, slip and demolding aids, dyes and pigments, stabilizers if necessary, e.g. against hydrolysis, light, heat or discoloration, inorganic and/or organic fillers, reinforcing agents and plasticizers. Suitable auxiliary materials and additives can be found, for example, in the Plastics Handbook, Volume 7 "Polyurethanes", Gerhard W. Becker and Dietrich Braun, Carl Hanser Verlag, Munich, Vienna, 1993.

To adjust the viscosity, a solvent can also be added to the reaction mixture at any time during the process according to the invention. Examples of solvents are triethyl phosphate (TEP), pentamethyldiethylenetriamine (PMDETA), triethylenediamine (TEDA), monoethylene glycol, polyethylene glycol and propylene carbonate (PC); and mixtures of two or more of the aforementioned solvents. In the event that the solvent is a polyol, it is advantageous to add it after the radical polymerization has ended.

To accelerate the reaction, a catalyst can be added to the reaction mixture in the process according to the invention.

Examples of suitable catalysts are N,N-dimethylethanolamine (DMEA), N,N-dimethylcyclohexylamine (DMCHA), bis(N,N-dimethylaminoethyl)ether (BDMAFE), N,N,N',N',N''-pentamethyldiethylenetriamine (PDMAFE), 1,4-diazadicyclo[2,2,2]octane (DABCO), 2-(2-dimethylaminoethoxy)ethanol (DMAFE), 2-((2-dimethylaminoethoxy)ethylmethylamino)ethanol, 1-(bis(3-dimethylamino)propyl)amino-2-propanol, N,N',N''-tris(3-dimethylaminopropyl)hexahydrotriazine, dimorpholinodiethyl ether (DMDEE), N,N-dimethylbenzylamine, N,N,N',N'',N''-pentamethyldipropylenetriamine, N,N'-diethylpiperazine. Particularly suitable here are sterically hindered primary, secondary or tertiary amines, such as dicyclohexylmethylamine, ethyldiisopropylamine, dimethylcyclohexylamine, dimethylisopropylamine, methylisopropylbenzylamine, methylcyclopentylbenzylamine, isopropyl-sec-butyl-trifluoroethylamine, diethyl-α-phenylethyl)amine, tris-n-propylamine, dicyclohexylamine, t-butylisopropylamine, di-t-butylamine, cyclohexyl-t-butylamine, de-sec-butylamine, dicyclopentylamine, di-α-trifluoromethylethyl)amine, di-(α-phenylethyl)amine, triphenylmethylamine, and 1,1,-diethyln-propylamine. Other sterically hindered amines include morpholines, imidazoles, ether compounds such as dimorpholinodiethyl ether or dimorpholinodimethyl ether; N-ethylmorpholine, N-methylmorpholine, bis(dimethylaminoethyl) ether, imidizole, nomethylimidazole, 1,2-dimethylimidazole, N,N,N',N',N'',N''-pentamethyldiethylenetriamine, N,N,N',N',N'',N''-pentaethyldiethylenetriamine, N,N,N',N',N'',N''-pentamethyldipropylenetriamine, bis(diethylaminoethyl) ether and bis(dimethylaminopropyl) ether.

According to the invention, monomer type A is an ethylenically unsaturated monomer which does not contain any active hydrogen and does not have any moisture-reactive functional groups.

According to the invention, a monomer of monomer type A is used in the process for producing the polymer composition. This is to be understood in such a way that at least one monomer of this type can be used here, i.e. also two, three, four or even more monomers of type A. Preferably, two monomers of monomer type A are used in the process.

Examples of monomer type A are selected from the group consisting of C1 to C12 esters of acrylic acid or methacrylic acid such as glycidyl acrylate, glycidyl methacrylate, methyl acrylate, ethyl acrylate, diethylhexyl acrylate, n-butyl acrylate, methyl methacrylate, ethyl methacrylate or n-butyl methacrylate, vinyl esters such as vinyl acetate or vinyl propionate, vinyl ethers, fumarates, maleates, styrenes, acrylonitriles, ethylenes, or mixtures thereof.

Particularly suitable as monomer type A is n-butyl methacrylate or diethylhexyl acrylate or a mixture thereof.

Monomer type A preferably acts as a co-initiator in the photoreaction. It is converted into a radical by H abstraction and a covalent bond is preferably formed between these monomers by reaction with the radical of monomer type C.

According to the invention, monomer type B is an ethylenically unsaturated monomer which does not contain active hydrogen and has a moisture-reactive functional group.

According to the invention, a monomer of monomer type B is used in the process for producing the polymer composition. This is to be understood as meaning that here at least one monomer of this type can be used, i.e. also two, three, four or even more monomers of type B. Preferably, exactly one monomer of monomer type B is used in the process.

It is furthermore advantageous if, within the scope of the invention, the monomer type B is selected from the group consisting of vinyl compounds, acrylates, methacrylates, fumarates, maleates, styrenes, acrylonitriles, ethylenes, or mixtures thereof, which have a moisture-reactive functional group.

A suitable moisture-reactive group is the isocyanate group or the silane group. Monomer type B preferably has a silane group as a moisture-reactive group.

Advantageously, the invention can provide that the monomer type B is selected from the group consisting of vinyltrichlorosilane, methylvinyldichlorosilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris(2-methoxyethoxy)silane, vinyltriacetoxysilane, vinylmethyldiethoxysilane, vinyldimethylethoxysilane, vinylmethyldimethoxysilane, vinyldimethylmethoxysilane, vinylmethyldiacetoxysilane, vinyltriisopropoxysilane, vinyltriisopropenoxysilane, vinyltris(methylethylketoximino)silane, divinyltetramethyldisiloxane, tetravinyltetramethylcyclotetrasiloxane, 3-acryloxypropyldimethylmethoxysilane, 3-acryloxypropyldimethylethoxysilane, 3-acryloxypropyltrimethoxysilane,3-acryloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-Methyacryloxy-propylmethyldiethoxysilane, 3-Methyacryloxypropylmethyldimethoxysilane, 3-Methacryloxy-propyl-tris(2 methoxyethoxy)silane, 4-(3-Trimethoxysilylpropyl)benzylstyrenesulfonate, allyl-triethoxysilane, allyltrimethoxysilane and oligomers of these silanes.

Methacryloxypropyltrimethoxysilane is particularly suitable as monomer type B.

According to the invention, monomer type c is an ethylenically unsaturated monomer which does not contain any active hydrogen and has a radical photoinitiator group. In the context of the present invention, a radical photoinitiator group is defined as a functional group which decomposes in a photolysis reaction after absorbing UV light and thus forms a radical as a reactive species which can start (initiate) a polymerization reaction.

The term “UV light” is defined according to the present invention as light with a wavelength of less than 400 nm. Sub-ranges of the UV light claimed here are thus UVA radiation with a wavelength of between 315 and 400 nm, UVB radiation with a wavelength of between 280 and 315 nm and UVC radiation with a wavelength of between 100 and 280 nm. Preferably, UVA and/or UVB radiation is used for UV-induced photolysis and thus for UV-induced curing.

According to the invention, a monomer of monomer type C is used in the process for producing the polymer composition. This is to be understood to mean that at least one monomer of this type can be used here, i.e. also two, three, four or even more monomers of type C. Preferably, exactly one monomer of monomer type C is used in the process.

In a preferred embodiment, the radical photoinitiator group of monomer type C is a radical photoinitiator group of type II. Type II photoinitiators abstract a hydrogen atom from a neighboring molecule. This then triggers the chain polymerization.

The radical photoinitiator group of type II is preferably a benzophenone group or an isopropylthioxanthone group.

Advantageously, the invention can provide that the monomer type C is selected from the group consisting of 4-methacryloyloxybenzophenone, 4-methacryloyloxyethoxybenzophenone, 4-methacryloyloxy-4'-methoxybenzophenone, 4-methacryloyloxyethoxy-4'-methoxybenzophenone, 4-methacryloyloxy-4'-bromobenzophenone, 4-acryloyloxyethoxy-4'-bromobenzophenone, 4-acryloyloxybenzophenone (ABP), 4-(2-acryloyloxy-ethoxy)benzophenone (AEBP), 4-(2-acryl-oyloxy-butoxy)benzophenone (ABBP), 4-(2-acryloyloxy-hexoxy)benzophenone (AHBP).

ABP or 4-methacryloyloxybenzophenone are particularly suitable as monomer type C.

According to the invention, a chain transfer agent is used in the radical polymerization process to reduce the average degree of polymerization of the finished polymer and to achieve a low-molecular molecular polymer. Chain transfer agents for radical polymerizations are known to those skilled in the art.

It may be advantageous if, within the scope of the invention, the chain transfer agent is a halogen-organic compound, an unsaturated aromatic compound or a thiol, which is preferably selected from the group consisting of tetrachloromethane, 2,4-diphenyl-4-methyl-1-pentene, dodecyl mercaptan, lauryl mercaptan, thioglycolic acid, octyl thioglycolate and thioglycerol.

The preferred chain transfer agent is dodecyl mercaptan.

Furthermore, it is conceivable that in the process for producing the polymer composition the polyol is present in an amount of from 20 percent by weight to 90 percent by weight, preferably from 40 percent by weight to 80 percent by weight and particularly preferably from 50 percent by weight to 60 percent by weight, based on the total weight of the polyol components, monomer types A to C.

Accordingly, it is conceivable that in the process for producing the polymer composition, the prepolymer with the terminal NCO groups is present in an amount of 20 percent by weight to 90 percent by weight, preferably from 40 percent by weight to 80 percent by weight and particularly preferably from 50 percent by weight to 60 percent by weight, based on the total weight of the components prepolymer, monomer type A, monomer type B and monomer type C.

In a further possibility, it can be provided that in the process for producing the polymer composition, the monomer type A is present in an amount of 30 percent by weight to 95 percent by weight, preferably from 50 percent by weight to 90 percent by weight and particularly preferably from 70 percent by weight to 85 percent by weight, based on the total weight of the monomer types A to C.

It may further be possible that in the process for preparing the polymer composition, monomer type B is present in an amount of from 5 percent by weight to 70 percent by weight, preferably from 10 percent by weight to 50 percent by weight, and particularly preferably from 15 percent by weight to 30 percent by weight, based on the total weight of monomer types A to C.

In a further possibility, it can be provided that in the process for producing the polymer composition, the monomer type C is present in an amount of 0.1 percent by weight to 5.0 percent by weight, preferably from 0.2 percent by weight to 4.0 percent by weight and particularly preferably from 0.3 percent by weight to 3.0 percent by weight, based on the total weight of the monomer types A, B and C.

According to a further advantage, it can be provided that the low molecular weight polymer has a number average molecular weight of 3,000 to 200,000 g/mol, preferably from 5,000 to 100,000 g/mol and particularly preferably from 10,000 to 60,000 g/mol.

In a second aspect, the invention relates to a polymer composition which can be produced or is produced by the process according to the invention.

The synthesis of the silane-modified ethylene-based polymer in a polyol according to the invention results in a polymer composition with improved properties compared to a silane-modified ethylene-based polymer that is synthesized in the PU prepolymer. Structurally, the formation of an interpenetrating network in the polymer composition according to the invention is advantageous for the physicochemical properties. It has increased temperature resistance and also improved barrier properties for oil.

If the optional step (c) is carried out in the process according to the invention, this polymer composition is characterized in that the polyol or the prepolymer is partially crosslinked with the low molecular weight polymer formed by radical polymerization.

Preferably, the polymer composition can have a glass transition temperature of between -50 and 100 °C, preferably between -40 and 70 °C and particularly preferably between -30 and 60 °C.

A further advantage can be achieved within the scope of the invention if it has a viscosity of 500 to 25,000 mPa.s, and preferably of 1,000 to 21,000 mPa.s measured at 90°C.

It can be advantageous if the polymer composition in the context of the invention is free of solvents. The further reaction with a polyisocyanate to form a polyurethane produces a solvent-free PU polymer.

The invention also relates to the use of the polymer composition according to at least one of the preceding claims as an adhesive, sealant or coating agent. In this case, it is particularly provided that the polymer composition cures as a one-component composition with moisture and by increasing the temperature to more than 100°C.

1. a) Bereitstellen einer erfindungsgemäßen Polymerzusammensetzung;
2. b) Zugabe von ausreichend Polyisocyanat, um den gewünschten Isocyanatgehalt und Isocyanat-Index zu erzielen, und Polymerisieren unter Anwendung eines Additionspolymerisationsverfahrens;
3. c) Optionale Zugabe eines Aminosilans oder eines Mercaptosilans und Umsetzung zu einem silanterminierten Polyurethan, und
4. d) Bestrahlung mit UV-Licht zur weiteren Vernetzung des Polymers.

The invention also relates to a process for producing a UV and moisture-curing polyurethane hot melt adhesive composition, the process comprising the following steps:

1. a) providing a polymer composition according to the invention;
2. b) adding sufficient polyisocyanate to achieve the desired isocyanate content and isocyanate index and polymerising using an addition polymerisation process;
3. c) Optional addition of an aminosilane or a mercaptosilane and conversion to a silane-terminated polyurethane, and
4. d) Irradiation with UV light to further crosslink the polymer.

By synthesizing the silane-modified ethylene-based polymer in a polyol according to the invention, a polyurethane hot melt adhesive composition with improved properties is obtained by using the polymer composition according to the invention compared to a silane-modified ethylene-based polymer that is synthesized in the PU prepolymer. The PU hot melt according to the invention has a higher temperature resistance, increased chemical resistance and improved adhesion to inorganic materials. In addition, the polymer composition obtained has improved barrier properties for oil. By using monomer type C, the polymer also becomes UV-curable, which enables rapid curing.

Commercially available polyisocyanates, especially diisocyanates, can be used as polyisocyanates for the production of the polyurethane polymer.

It may further be possible that the polyisocyanate is selected from the group consisting of ethylene diisocyanate, ethylidene diisocyanate, propylene diisocyanate, butylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate (HDI), toluene diisocyanate, cyclopentylene-1,3-diisocyanate, cyclohexylene-1,4-diisocyanate, cyclohexylene-1,2-diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diisocyanatodicyclohexylmethane, 2,2-diphenylpropane-4,4'-diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, xylylene diisocyanate, 1,4-naphthylene diisocyanate, 1,5-naphthylene diisocyanate, diphenyl-4,4'-diisocyanate, Azobenzene-4,4'-diisocyanate, diphenylsulfone-4,4'-diisocyanate, dichlorohexamethylene diisocyanate, furfurylidene diisocyanate, 1-chlorobenzene-2,4-diisocyanate, 4,4',4''-triisocyanato-triphenylmethane, 1,3,5-triisocyanato-benzene, 2,4,6-triisocyanato-toluene and 4,4'-dimethyldiphenylmethane-2,2',5,5-tetraisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-bis(isocyanatomethyl)benzene, 1,3-bis(isocyanatomethyl)cyclohexane, block diisocyanates and carbodiimide-modified polyisocyanates, as well as any mixtures and precondensates of the aforementioned isocyanates.

Examples of precondensates include HDI biuret and HDI cyanurate.

The polyisocyanate is preferably an aliphatic isocyanate.

Advantageously, within the scope of the invention, it can be provided that in the process for producing a moisture-curing polyurethane hot melt adhesive composition, the free isocyanate content is between 0 and 20%, preferably between 0 and 15% and particularly preferably between 0 and 10%.

According to a further possibility, it can be provided that in this process the isocyanate index is between 0.5 and 10, preferably between 1 and 3 and particularly preferably between 1.5 and 2.5.

According to the optional step c), the UV and moisture-curing polyurethane hot melt adhesive composition obtained in step b) can be converted into a silane-terminated polyurethane by adding an aminosilane or a mercaptosilane.

According to the invention, an aminosilane or a mercaptosilane is used in step c). This is to be understood as meaning that at least one aminosilane or one mercaptosilane can be used here, i.e. also two, three, four or even more aminosilanes or mercaptosilanes. Preferably, exactly one aminosilane or exactly one mercaptosilane is used in the process.

Preferably, the aminosilane is an aminosilane AS of formula (I),

The radical R ¹ is a linear or branched, monovalent hydrocarbon radical having 1 to 12 C atoms, which optionally has one or more CC multiple bonds and/or optionally cycloaliphatic and/or aromatic moieties. In particular, R ¹ is a methyl, ethyl or isopropyl group.

The radical R ² represents an acyl radical or a linear or branched, monovalent hydrocarbon radical having 1 to 12 C atoms, which optionally has one or more CC multiple bonds and/or optionally cycloaliphatic and/or aromatic moieties. The radical R ² preferably represents an acyl or alkyl group having 1 to 5 C atoms, in particular a methyl or an ethyl or an isopropyl group.

The radical R ³ is a linear or branched, divalent hydrocarbon radical having 1 to 12 C atoms, which optionally has cyclic and/or aromatic moieties, and optionally one or more heteroatoms. The radical R ³ is preferably an alkylene radical having 1 to 3 C atoms, in particular having 3 C atoms.

Furthermore, the index a stands for a value of 0, 1 or 2, in particular for 0 or 1.

The radical R ⁴ represents a hydrogen atom or a linear or branched hydrocarbon radical having 1 to 20 C atoms, which optionally has cyclic moieties, or represents a radical of the formula (II).

The radicals R ⁶ and R ⁷ independently of one another represent a hydrogen atom or a radical from the group comprising -R ⁹ , -CN and -COOR ⁹ .

The radical R ⁸ stands for a hydrogen atom or for a radical from the group comprising -CH ₂ -COOR ⁹ , -COOR ⁹ , -CONHR ⁹ , -CON(R ⁹ ) ₂ , -CN, -NO ₂ , -PO(OR ⁹ ) ₂ , -SO ₂ R ⁹ and - SO ₂ OR ⁹ .

The radical R ⁹ represents a hydrocarbon radical having 1 to 20 C atoms, optionally containing at least one heteroatom.

Examples of suitable aminosilanes AS of the formula (I) are primary aminosilanes such as 3-aminopropyltrimethoxysilane, 3-aminopropyldimethoxymethylsilane; secondary aminosilanes such as N-butyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane; the products from the Michael-like addition of primary aminosilanes such as 3-aminopropyltrimethoxysilane or 3-aminopropyldimethoxymethylsilane to Michael acceptors such as acrylonitrile, acrylic and methacrylic acid esters, acrylic or methacrylic acid amides, maleic and fumaric acid diesters, citraconic acid diesters and itaconic acid diesters, for example N-(3-trimethoxysilyl-propyl)-amino-succinic acid dimethyl ester and diethyl ester; and analogues of the aminosilanes mentioned with ethoxy or isopropoxy groups instead of the methoxy groups on the silicon. Particularly suitable as aminosilanes AS are secondary aminosilanes, in particular aminosilanes AS in which R4 in formula (I) is other than H. Preference is given to the Michael-type adducts, in particular N-(3-trimethoxysilyl-propyl)-amino-succinic acid diethyl ester.

In the present document, the term “Michael acceptor” refers to compounds which, due to the double bonds they contain which are activated by electron acceptor residues, are capable of entering into nucleophilic addition reactions with primary amino groups (NH ₂ groups) in a manner analogous to the Michael addition (hetero-Michael addition).

In a further aspect, the invention relates to a UV and moisture-curing polyurethane hot melt adhesive composition which can be produced or is produced by the method disclosed above.

A further advantage can be achieved within the scope of the invention if the polyurethane hot melt adhesive composition has a viscosity of 10 mPas to 150,000 mPas at 120°C. The viscosity is preferably between 1,000 and 100,000 mPas, particularly preferably between 3,000 and 75,000 mPas and in particular between 2,000 and 50,000 mPas.

The invention also relates to the use of the UV- and moisture-curing polyurethane hot melt adhesive composition according to the invention as an adhesive, sealant or coating agent. In this case, it is particularly intended that it is used as an adhesive.

1. a) Bereitstellen der erfindungsgemäßen Polymerzusammensetzung wobei, bei dessen Herstellung anstelle der Temperaturerhöhung im optionalen Schritt c) das Polymerisat auf eine Temperatur von 80 bis 20°C abgekühlt wird;
2. b) Zugabe eines erfindungsgemäßen Polyisocyanats, um einen gewünschten freien Isocyanatgehalt und gewünschten Isocyanat-Index zu erzielen;
3. c) optionales Abkühlen auf eine Temperatur von 80 bis 20 °C für eine Zeitdauer von 0,5 bis 5 Stunden.

The invention also relates to a process for producing a 1K polyurethane adhesive comprising the following steps:

1. a) providing the polymer composition according to the invention, wherein, during its preparation, instead of increasing the temperature in the optional step c), the polymer is cooled to a temperature of 80 to 20°C;
2. b) adding a polyisocyanate according to the invention to achieve a desired free isocyanate content and desired isocyanate index;
3. c) optional cooling to a temperature of 80 to 20 °C for a period of 0.5 to 5 hours.

Commercially available polyisocyanates, preferably diisocyanates and in particular aliphatic diisocyanates, can be used as polyisocyanates for the production of the polyurethane polymer.

It may further be possible that the polyisocyanate is selected from the group consisting of ethylene diisocyanate, ethylidene diisocyanate, propylene diisocyanate, butylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, cyclopentylene-1,3-diisocyanate, cyclohexylene-1,4-diisocyanate, cyclohexylene-1,2-diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diisocyanatodicyclohexylmethane, 2,2-diphenylpropane-4,4'-diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, xylylene diisocyanate, 1,4-naphthylene diisocyanate, 1,5-naphthylene diisocyanate, diphenyl-4,4'-diisocyanate, azobenzene-4,4'-diisocyanate, Diphenylsulfone-4,4'-diisocyanate, dichlorohexamethylene diisocyanate, furfurylidene diisocyanate, 1-chlorobenzene-2,4-diisocyanate, 4,4',4''-triisocyanato-triphenylmethane, 1,3,5-triisocyanato-benzene, 2,4,6-triisocyanato-toluene and 4,4'-dimethyldiphenylmethane-2,2',5,5-tetraisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-bis(isocyanatomethyl)benzene, 1,3-bis(isocyanatomethyl)cyclohexane, block diisocyanates and carbodiimide-modified polyisocyanates, polymeric diphenylmethane diisocyanate (PMDI), as well as any mixtures of the aforementioned isocyanates.

In a preferred embodiment, diphenylmethane isocyanate (MDI) or polymeric diphenylmethane diisocyanate (PMDI) is used as the polyisocyanate.

The MDI can be a mixture of two or three of its isomers, namely 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, or 4,4'-diphenylmethane diisocyanate. However, only one isomer can be used, which is then preferably 4,4'-diphenylmethane diisocyanate.

Polymeric diphenylmethane diisocyanate (PMDI), also known as technical MDI, is a mixture of methylene diphenyl isocyanates and homologous aromatic polyisocyanates. However, the term "polymeric diphenylmethane diisocyanate" is actually technically incorrect, as it is not a polymer, but a mixture of compounds with several (typically up to 6) phenylene groups, each of which has an isocyanate group. A common trade name is also polymethylene polyphenyl isocyanate.

According to an advantageous development of the invention, it can be provided that the free isocyanate content set in step b) of the process is between 2 and 40%, preferably between 5 and 30% and particularly preferably between 10 and 20%.

Furthermore, within the scope of the invention, it is conceivable that the isocyanate index set in step b) of the process is between 1.5 and 20, preferably between 2 and 15 and particularly preferably between 4 and 10.

In a further aspect, the invention relates to a 1K polyurethane adhesive which can be produced or is produced by the method disclosed above.

According to a further possibility, the 1K polyurethane adhesive can have a viscosity of 5,000 to 25,000 mPa.s, and preferably of 6,000 to 21,000 mPa.s, measured at 20 °C.

The invention also relates to the use of the 1K polyurethane adhesive according to the invention as an adhesive, coating compound or sealant, in particular as a multi-purpose adhesive, assembly adhesive, construction adhesive, paper and packaging adhesive, film laminating adhesive, adhesive for ceramic and metallic materials, wood, glass, sandwich systems, textiles, reinforcing fabrics, materials in the aircraft, military or shipbuilding sectors.

1. a) 5 bis 90 Gew.-% eines Urethanpolymers oder Urethanvorpolymers, hergestellt durch Additionspolymerisation eines Polyisocyanats und eines Polyols;
2. b) 10 bis 95 Gew.-% eines niedrigmolekularen Polymers von ethylenisch ungesättigten Monomeren, die keinen aktiven Wasserstoff enthalten, wobei mindestens eines der Monomere ein ethylenisch ungesättigtes Monomer mit einer Siloxangruppe ist.

The invention relates in a further aspect to a polyurethane composition comprising

1. a) 5 to 90% by weight of a urethane polymer or urethane prepolymer prepared by addition polymerization of a polyisocyanate and a polyol;
2. b) 10 to 95 wt.% of a low molecular weight polymer of ethylenically unsaturated monomers containing no active hydrogen, wherein at least one of the monomers is an ethylenically unsaturated monomer having a siloxane group.

In one embodiment of the invention, the polyurethane composition is characterized in that the low molecular weight polymer consists of more than 50%, preferably more than 75% and further preferably 100% of an ethylenically unsaturated monomer having a siloxane group.

In a preferred embodiment of the invention, the polyurethane composition is characterized in that the ethylenically unsaturated monomer having a siloxane group is a silane-modified acrylate.

In a second aspect, the invention relates to the use of an ethylenically unsaturated monomer having a siloxane group for copolymerization with ethylenically unsaturated monomers which do not contain active hydrogen in a polyol or in a prepolymer having the terminal NCO groups as solvent.

In one embodiment of the invention, the use is characterized in that the ethylenically unsaturated monomer having a siloxane group is a silane-modified acrylate.

1. a) 5 bis 95 Gew.-% eines oder mehrerer Acrylate-Monomere, die keinen aktiven Wasserstoff enthalten, bevorzugt ausgewählt aus der Gruppe bestehend aus Butylmethacrylat und Methylmethacrylat;
2. b) 5 bis 95 Gew.-% eines oder mehrerer Acrylatmonomere mit einer Siloxan-Seitengruppe, bevorzugt ein 3-Methacryloxypropyltrimethoxysilan.

In an additional aspect, the invention relates to an acrylate copolymer comprising:

1. a) 5 to 95 wt.% of one or more acrylate monomers which do not contain active hydrogen, preferably selected from the group consisting of butyl methacrylate and methyl methacrylate;
2. b) 5 to 95 wt.% of one or more acrylate monomers having a siloxane pendant group, preferably a 3-methacryloxypropyltrimethoxysilane.

1. a. Bereitstellen der erfindungsgemäßen Polymerzusammensetzung wobei anstelle der Temperaturerhöhung im optionalen Schritt b. des Verfahrens das Polymerisat auf eine Temperatur von 80 bis 20°C abgekühlt wird und die Polymerzusammensetzung Epoxidgruppen aufweist, entweder eingebracht über eines der Monomere A bis C, die zusätzlich eine Epoxidgruppe als funktionelle Gruppe aufweisen oder eingebracht über ein weiteres ethylenisch ungesättigten, keinen aktiven Wasserstoff enthaltenden Monomer, das eine Epoxidgruppe als funktionelle Gruppe aufweist (Monomertyp D);
2. b. Zugabe eines Polyisocyanats, um einen gewünschten freien Isocyanatgehalt und gewünschten Isocyanat-Index zu erzielen;
3. c. optionales Abkühlen auf eine Temperatur von 80 bis 20 °C für eine Zeitdauer von 0,5 bis 5 Stunden.

In a further aspect, the invention relates to a process for producing a 2K polyurethane adhesive, the process comprising the following steps:

1. a. Providing the polymer composition according to the invention, wherein instead of increasing the temperature in optional step b. of the process, the polymer is cooled to a temperature of 80 to 20°C and the polymer composition has epoxy groups, either introduced via one of the monomers A to C, which additionally have an epoxy group as a functional group or introduced via another ethylenically unsaturated monomer which does not contain any active hydrogen and has an epoxy group as a functional group (monomer type D);
2. b. Addition of a polyisocyanate to achieve a desired free isocyanate content and desired isocyanate index;
3. c. optional cooling to a temperature of 80 to 20 °C for a period of 0.5 to 5 hours.

Through these process steps a. to c, the first component of the 2K polyurethane adhesive is produced, which can then be reacted with an epoxy-reactive monomer or prepolymer as the second component of the 2K polyurethane adhesive.

In the claimed method for producing a 2K polyurethane adhesive, the second epoxy-reactive component is preferably an amine compound. The person skilled in the art can use the known amine compounds that are suitable for reacting with the epoxy, such as diamines, polyamines, aliphatic amines, aromatic amines, primary amines or secondary amines. Furthermore, a prepolymer with terminal reactive groups such as amine group, hydroxy group and thiol group can be used, whereby prepolymer with terminal isocyanate groups can be used.

In a further aspect, the invention relates to a 2K polyurethane adhesive which has been produced by the method described above.

The invention also relates to the use of the 2K polyurethane adhesive according to the invention as an adhesive, coating compound or sealant, in particular as a multi-purpose adhesive, assembly adhesive, construction adhesive, paper and packaging adhesive, film laminating adhesive, adhesive for ceramic and metallic materials, wood, glass, sandwich systems, textiles, reinforcing fabrics, materials in the aircraft, military or shipbuilding sectors.

Definitions

In this document, substance names beginning with “poly”, such as polyol or polyisocyanate, refer to substances that formally contain two or more of the functional groups mentioned in their name per molecule.

In this document, the term "polymer" includes, on the one hand, a collective of chemically uniform macromolecules that differ in terms of degree of polymerization, molecular weight and chain length, which were produced by a polyreaction (polymerization, polyaddition, polycondensation). On the other hand, the term also includes derivatives of such a collective of macromolecules from polyreactions, i.e. compounds that were obtained by reactions, such as additions or substitutions, of functional groups on given macromolecules and which can be chemically uniform or chemically non-uniform. The term also includes copolymers and so-called prepolymers, i.e. reactive oligomeric pre-adducts whose functional groups are involved in the construction of macromolecules.

1. 1.) statistische Copolymere, in denen die Verteilung der beiden Monomeren in der Kette einer statistischen Verteilung folgt,
2. 2.) Gradientcopolymere, die prinzipiell den statistischen Copolymeren ähnlich sind, in denen jedoch der Anteil des einen Monomers im Verlauf der Kette zu- und des anderen abnimmt,
3. 3.) Alternierende Copolymere, in denen sich die beiden Monomere abwechseln,
4. 4.) Blockcopolymere und Segmentcopolymere, die aus längeren Sequenzen oder Blöcken jedes Monomers besteht, und
5. 5.) Pfropfcopolymere (engl.: graft copolymers), bei denen Blöcke eines Monomers auf das Gerüst (Rückgrat) eines anderen Monomers aufgepfropft sind.

The term “copolymer” in this document refers to a polymer that is composed of two or more different types of monomer units. This distinguishes the copolymer from a homopolymer, which is composed of only one type of monomer (real or imaginary) and therefore has only one repeating unit. Copolymers can be divided into five classes, namely

1. 1.) statistical copolymers, in which the distribution of the two monomers in the chain follows a statistical distribution,
2. 2.) Gradient copolymers, which are in principle similar to statistical copolymers, but in which the proportion of one monomer increases and the other decreases along the chain,
3. 3.) Alternating copolymers, in which the two monomers alternate,
4. 4.) Block copolymers and segment copolymers consisting of longer sequences or blocks of each monomer, and
5. 5.) Graft copolymers, in which blocks of one monomer are grafted onto the backbone of another monomer.

The term "polyurethane polymer" includes all polymers that are produced using the so-called diisocyanate polyaddition process. This also includes polymers that are almost or completely free of urethane groups. Examples of polyurethane polymers are polyether polyurethanes, polyester polyurethanes, polyether polyureas, polyureas, polyester polyureas, polyisocyanurates and polycarbodiimides.

In this document, an "active hydrogen" is understood to mean a hydrogen bonded to N, O or S (also referred to synonymously as "Zerewitinoff active hydrogen") if it yields methane by reaction with methylmagnesium iodide according to a process discovered by Zerewitinoff. Typical examples of compounds with active hydrogen are compounds that contain carboxyl, hydroxyl, amino, imino or thiol groups as functional groups.

Accordingly, the monomer that does not contain active hydrogen (monomer type B) is a monomer that does not contain any carboxyl, hydroxyl, amino, imino or thiol groups.

According to the present application, a "functional group" is a group of atoms in an organic compound that significantly determines the material properties and the reaction behavior of the compound that carries it. Chemical compounds that carry the same functional groups are grouped into substance classes due to their often similar properties.

In this document, a "moisture-reactive functional group" is understood to mean a functional group that reacts with water. This reaction can lead to the cross-linking of two or more such groups and thus to the curing of the corresponding polymer. The person skilled in the art is familiar with moisture-reactive (curable) groups in the field of polymers. Examples include the silane group and the isocyanate group.

In this document, a “UV-curing composition” is understood to mean a polymer composition (preferably a polyurethane adhesive) which cures at least partially upon irradiation with UV light due to the presence of radical photoinitiator groups in the polymer.

A “radical photoinitiator group” is defined in the context of the present invention as a functional group which, after absorption of UV light, decomposes in a photolysis reaction and thus forms radicals as reactive species that can start (initiate) a polymerization reaction.

The term “UV light” is defined according to the present invention as light with a wavelength of less than 400 nm. Sub-ranges of the UV light claimed here are thus UVA radiation with a wavelength of between 315 and 400 nm, UVB radiation with a wavelength of between 280 and 315 nm and UVC radiation with a wavelength of between 100 and 280 nm. Preferably, UVA and/or UVB radiation is used for UV-induced photolysis and thus for UV-induced curing.

In the present document, the terms "silane" or "organosilane" refer to compounds which, on the one hand, have at least one, usually two or three, alkoxy groups or acyloxy groups bonded directly to the silicon atom via Si-O bonds, and, on the other hand, have at least one organic radical bonded directly to the silicon atom via a Si-C bond. Such silanes are also known to the person skilled in the art as organoalkoxysilanes or organoacyloxysilanes.

Accordingly, the term “silane group” refers to the silicon-containing group bound to the organic residue of the silane via the Si-C bond. The silanes, or rather their silane groups, have the property of hydrolyzing when in contact with moisture and are therefore moisture-reactive groups.

“Aminosilanes” or “mercaptosilanes” are organosilanes whose organic residue has an amino group or a mercapto group. “Primary aminosilanes” are aminosilanes that have a primary amino group, i.e. an NH2 group that is bonded to an organic residue. “Secondary aminosilanes” are aminosilanes that have a secondary amino group, i.e. an NH group that is bonded to two organic residues.

In this document, "molecular weight" means the molar mass (in grams per mole or in daltons) of a molecule. In this document, "average molecular weight" always means the number average of the molecular weight distribution M _n (number average). The term "number average molar mass" is also used as a synonym for "average molecular weight".

In the present document, a “low molecular weight polymer” is understood to mean a polymer with an average molecular weight M _n of less than 200,000 g/mol. The average molecular weight M _n is preferably less than 100,000 g/mol, particularly preferably less than 80,000 g/mol, furthermore particularly preferably less than 60,000 g/mol I and in particular less than 20,000 g/mol. The low molecular weight polymer can, for example, have an average molecular weight M _n of 3,000, 4,000, 5,000, 6,000, 7,000, 8,000, 9,000. 10,000, 15,000, 20,000, 25,000, 30,000, 35,000, 40,000, 45,000, 50,000, 55,000, 60,000, 65,000, 70,000, 75,000, 80,000, 85,000, 90,000, 95,000 and 100,000 g/mol.

The term "polymeric diphenylmethane diisocyanate" (PMDI) is a mixture of methylene diphenyl isocyanates and homologous aromatic polyisocyanates. From a chemical point of view, the term "polymeric diphenylmethane diisocyanate" is a misnomer, as it is not a polymer, but a mixture of compounds with several (typically up to 6) phenylene groups, each of which carries an isocyanate group. A common trade name is also polymethylene polyphenyl isocyanate.

In the context of the present application, a "chain transfer agent" is defined as an organic molecule that can carry out a chain transfer. A chain transfer reaction is a reaction during a chain polymerization in which the activity of a growing polymer chain is transferred to another molecule. Chain transfer reactions reduce the average degree of polymerization of the finished polymer. Chain transfer agents for radical polymerizations are known to those skilled in the art.

In this document, the term “solvent” refers to compounds as listed as organic solvents in CD Römpp Chemie Lexikon, 9th edition, version 1.0, Georg Thieme Verlag, Stuttgart 1995. The polyols or prepolymers with terminal NCO groups used according to the invention are not covered by this definition, although they act as solvents for the monomers and also the low molecular weight polymer formed by radical polymerization.

In this document, "solid" means substances that do not change their shape without external influence or that are difficult to deform, but in particular they are not flowable. "Liquid" means substances that can be deformed and are flowable, which also includes highly viscous and pasty substances.

In this document, "one-component" (abbreviated as "1K") refers to a composition in which all components of the composition are mixed and stored in the same container and which can be cured with moisture. In this document, "two-component" refers to a composition in which the components of the composition are present in two different components that are stored in separate containers. The two components are only mixed together shortly before or during the application of the composition, after which the mixed composition hardens, with the curing only taking place or being completed by the effect of moisture.

It should be expressly pointed out that in the context of this patent application, indefinite articles and indefinite numerical statements such as "one...", "two..." etc. should generally be understood as at least statements, i.e. as "at least one...", "at least two..." etc., unless the context or the specific text of a particular passage indicates that only "exactly one...", "exactly two..." etc. are meant. Furthermore, all numerical statements and statements on process parameters and/or device parameters are to be understood in the technical sense, i.e. as subject to the usual tolerances. The explicit specification of the restriction "at least" also or “at least” or similar, it must not be concluded that the simple use of “a”, i.e. without specifying “at least” or similar, means “exactly one”.

Unless otherwise stated, the percentages in this document are by weight.

The embodiments shown here are only examples of the present invention and should therefore not be understood as limiting. Alternative embodiments considered by those skilled in the art are equally included within the scope of the present invention.

Examples of implementation

1. Production of a UV-curing polyacrylate as a base formulation

Based on the recipe of a polyacrylate IC2068 (see Table 1), the copolymerizable photoinitiator 4-methacryloxybenzophenone was varied in proportions of 1 - 5% in these experiments, thus producing the polyacrylate batches IC2068-7 to IC2068-11. The ratio of diethylhexyl acrylate to 4-methacryloxybenzophenone changed from 12:1 to 2.4:5.

In order to produce a radiation-curing polyacrylate (and alternatively a polysilane acrylate), the solvent polyether polyol is heated to 90 °C in a glass reactor under a nitrogen atmosphere. During heating, the monomers and the initiator are added within 30 minutes. As soon as the temperature of 90 °C is reached, stirring is continued for 30 minutes. The monomers and the initiator are then added within 2 hours at 90 °C. The post-reaction then takes place within 2 hours with further dosing of the initiator. Table 1: Polyacrylate batches IC2068-07 to -11 raw materials IC2068-7 IC2068-8 IC2068-9 IC2068-10 IC2068-11 PPG1000 58.0 58.0 58.0 58.0 58.0 Start reaction N-butyl methacrylate 6.8 7.0 7.2 7.5 7.9 Diethylhexyl acrylate 3.4 3.4 3.4 3.4 3.4 4-Methacryloxybenzophenone 1.4 1.15 0.9 0.6 0.3 Lauryl mercaptan 0.2 0.2 0.2 0.2 0.2 Dimethyl-2,2'-azobisisobutyrate 0.5 0.5 0.5 0.5 0.5 dosage Dimethyl-2,2'-azobisisobutyrate 0.25 0.25 0.25 0.25 0.25 N-butyl methacrylate 17.0 17.8 18.6 19.3 19.9 Diethylhexyl acrylate 8.6 8.6 8.6 8.6 8.6 4-Methacryloxybenzophenone 3.6 2.85 2.1 1.4 0.7 After-reaction Dimethyl-2,2'-azobisisobutyrate 0.25 0.25 0.25 0.25 0.25 (PPG 1000 =Polypropylene glycol MW = 1000)

The viscosity hardly differs within the test series (see Table 2). Tack measurements using an oscillation and rotation rheometer also verify the assumption that the proportion of 4-methacryloxybenzophenone used initially has little influence on the technical parameters.

2. Rheological characterization of UV-curing polyacrylates

The polyacrylates IC2068-7 to IC2068-11, prepared according to Table 1, were rheologically investigated. First, the viscometer was used in a Brookfield-CAP2000+ viscometer (AMETEK GmbH, Meerbusch, Germany) the viscosity was determined at a temperature of 90°C. In addition, the stickiness (so-called tack'') was also determined at a polymer temperature of 90°C in an oscillation and rotation rheometer MCR 302 (Anton Paar, Graz, Austria) under the following measuring conditions: measuring plate PP2, gap: 0.1 mm, pre-shear 1000 1/s. The results are shown in Table 2. Table 2: Measurement results for the polyacrylates of the test series IC2068 Brookfield Cap2000+ Rheometer Test no . Viscosity @ 90 °C [mPas] Tack @ 90 °C [Nmm] IC2068-7 2,200 0.13 IC2068-8 2,000 0.13 IC2068-9 2,000 0.13 IC2068-10 1,800 0.10 IC2068-11 1,800 0.10

As the results shown in Table 2 show, the viscosity hardly differs within the test series. Tack measurements using an oscillation and rotation rheometer also verify the assumption that the proportion of 4-methacryloxybenzophenone used initially has little influence on the technical parameters of the polyacrylate polymer. This provides the technological basis for the production of silane-modified polyacrylates.

3. Conversion of UV-curing polyacrylates to polyurethane

In order to produce a polyurethane adhesive, the polyacrylates IC2068-7 to IC2068-11 produced according to Table 1 were reacted with the addition of 4,4'-diphenylmethane diisocyanate (4,4'-MDI) and additives (UV markers, defoamers, stabilizers) according to Table 3 to form the UV-curable polyurethane prepolymers UV-10 to UV 14. Additional polyols and additives can be added to the polyacrylate/polysilane acrylate at 90 °C. Homogenization takes place for 45 minutes at approx. 10 mbar. The 4,4'-MDI is then added and stirred for 60 minutes. Before filling the polyurethane adhesive, it is degassed again at approx. 10 mbar. Table 3: Test batches UV 10 to UV 14 raw materials UV10 UV11 UV12 UV13 UV14 2068-7 78.8 2068-8 78.8 2068-9 78.8 2068-10 78.8 2068-11 78.8 Additive 0.2 0.2 0.2 0.2 0.2 4,4'-MDI 21.0 21.0 21.0 21.0 21.0

4. Rheological characterization of UV-curing polyurethanes

The polyurethane adhesives UV 10 to UV 14 produced according to Table 31 were rheologically investigated. First, the viscosity was determined at a temperature of 90°C in a Brookfield-CAP2000+ viscometer (AMETEK GmbH, Meerbusch, Germany) (spindle 1.5 rpm). In addition, the stickiness (so-called tack'') was also determined at a polymer temperature of 90°C in an oscillation and rotation rheometer MCR302 under the following measuring conditions: measuring plate PP12, gap: 0.1 mm, pre-shear 1000 1/s. The results are shown in Table 4. Table 4: Measurement results for polyurethane adhesives UV 10 to UV 14 Brookfield Cap2000+ Rheometer Test no . Viscosity @90 °C [mPas] Tack @90 °C [Nmm] UV10 3,800 0.40 UV11 3,700 0.30 UV12 4,600 0.45 UV13 3,600 0.30 UV14 3,800 0.45

As the measurement results in Table 4 show, the UV-active polyurethane adhesives UV 10 to UV 14 have a low viscosity when applied at 90 °C and are characterized by low inherent tack.

5. UV-induced bonding of UV-curing polyurethanes

Using a 180° peel test and a loop tack test (based on DIN EN 1713) with the help of a traction machine, the effectiveness of UV activity was investigated in more detail within the test series UV 10 to 14 (see 1 and 2 ). Adhesives were applied to an aluminum foil (foil thickness = 30 µm) in a layer thickness of 50 µm at 90 °C, exposed to UV light (UV belt dryer UN50029, Technigraf, Gräfenwiesbach, Germany, wavelength range = 200 to 400 nm), then glued directly to a glass plate and rolled on with a 2 kg hand roller. After 10 minutes, the tests were carried out on the traction machine. With a UV exposure time of 10 s, an energy quantity of approx. 800 J/cm is generated, whereas with 20 s an energy quantity of approx. 1,600 J/cm is generated.

The 1 and 2 The results presented can be summarized as follows: The higher the proportion of photoinitiator, the lower the energy input required via UV exposure and the less yellowing of the polyurethane adhesive. UV 10 is therefore the optimal formulation, particularly in terms of the 5-fold increase in surface tack and the increase in adhesive strength. The successful findings were successfully transferred to the use of UV silane acrylates in the PU system. This was produced in accordance with a further test.

6. Preparation of a UV-curing silane-modified polyacrylate

Based on the polymerization of acrylate polymers in polyols, the base formulation IC2068-8 according to Table 1 was modified by using a silane-containing methacrylate monomer to obtain the UV- and moisture-curable silane-acrylate IC2068-12. The organofunctional 3-methacryloxypropyltrimethoxysilane was used at 3.0%. The recipe and the reaction procedure are shown in Table 5.

In order to produce a silane-modified acrylate polymer, the initial mixture is heated to 90 °C in a glass reactor under a nitrogen atmosphere. After 30 minutes, the monomers are added over a period of 2 hours at 90 °C and the initiator is added.

The post-reaction then takes place within 2 hours with additional addition of the initiator. Table 5: Formulation of the UV-curing silane-modified acrylate UV2068-12 raw materials IC2068-8 (base) IC2068-12 PPG1000 58.0 58.0 Start reaction N-butyl methacrylate 7 4.9 Diethylhexyl acrylate 3.4 2.5 Methacryloxypropyltrimethoxysilane 0 3.0 4-Methacryloxybenzophenone 1.15 1.0 Lauryl mercaptan 0.2 0.2 Dimethyl-2,2'-azobisisobutyrate 0.5 0.5 dosage Dimethyl-2,2'-azobisisobutyrate 0.25 0.25 N-butyl methacrylate 17.8 12.3 Diethylhexyl acrylate 8.6 6.2 Methacryloxypropyltrimethoxysilane 0 7.8 4-Methacryloxybenzophenone 2.85 2.6 After-reaction Dimethyl-2,2'-azobisisobutyrate 0.25 0.25

7. Rheological characterization of UV-curing silane-modified polyacrylates

The UV-curing silane-modified polyacrylate variant IC2068-12 was also rheologically tested using the same method in comparison to the base formulation IC2068-8: Table 6: Measurement results for the UV-curing silane-modified polyacrylate IC2068-12 Brookfield Cap2000+ Rheometer Test no . Viscosity @ 90 °C [mPas] Tack @ 90 °C [Nmm] IC2068-8 (base) 2,000 0.13 IC2068-12 1,500 0.07

Similar properties can be found through rheological investigations.

8. Conversion of UV-curing silane-modified polyacrylates to polyurethane

In order to produce a polyurethane adhesive, the polyacrylate IC2068-12 produced according to Table 5 was converted into the UV-curable polyurethane prepolymer UV 15 with the addition of 4,4'-diphenylmethane diisocyanate (4,4'-MDI) and additives according to Table 7. Additional polyols and additives can be added to the polyacrylate/polysilane acrylate at 90 °C. Homogenization takes place for 45 minutes at approx. 10 mbar. The 4,4'-MDI is then added and stirred for 60 minutes. Before filling the polyurethane adhesive, it is degassed again at approx. 10 mbar. Table 7: Test batch UV 15 raw materials UV 11 (base) UV15 2068-8 78.8 2068-12 78.8 Additive 0.2 0.2 4,4'-MDI 21.0 21.0

9. Rheological characterization of UV-curing silane-modified polyurethanes

The polyurethane adhesive UV 15, produced according to Table 7, was also rheologically tested using the same method in comparison to the basic formulation UV 11: Table 8: Measurement results for the UV-curing silane-modified polyurethane adhesive UV 15 Brookfield Cap2000+ Rheometer Test no . Viscosity @90 °C [mPas] Tack @90 °C [Nmm] UV11 3,700 0.30 UV15 6,500 0.80

Rheological investigations reveal slight modifications in the properties.

10. UV-induced bonding of UV-curing polyurethanes

Using a 180° peel test and a loop tack test (based on DIN EN 1713) using a traction machine, the adhesive strength was investigated as a function of the UV irradiation time for the UV-curing silane-modified polyurethane adhesive UV 15 in comparison to the basic formulation UV 11 (see 3 and 4 ). Adhesives were applied to an aluminum foil (foil thickness = 30 µm) in a layer thickness of 50 µm at 90 °C, exposed to UV light (UV belt dryer UN50029, Technigraf, Gräfenwiesbach, Germany, wavelength range = 200 to 400 nm), then glued directly to a glass plate and rolled on with a 2 kg hand roller. After 10 minutes, the tests were carried out on the traction machine. With a UV exposure time of 10 s, an energy quantity of approx. 800 J/cm is generated, whereas with 20 s an energy quantity of approx. 1,600 J/cm is generated.

As the 3 and 4 show that the silane-modified polymer UV 15 has improved adhesive strength in both test methods compared to the basic formulation UV 11. The optimal UV irradiation time was 20 to 30 seconds.

CHARACTERS

• 1 die UV-induzierte Verklebung anhand eines 180° Peel-Tests für die gemäß der Tabelle 3 hergestellten Polyurethanklebstoffe UV 10 bis UV 14. Aufgetragen ist die Klebkraft in Newton in Abhängigkeit von der UV-Bestrahlungsdauer in Sekunden.
• 2 die UV-induzierte Verklebung anhand eines Loop-Tack-Tests für die gemäß der Tabelle 3 hergestellten Polyurethanklebstoffe UV 10 bis UV 14. Aufgetragen ist die Klebkraft in Newton in Abhängigkeit von der UV-Bestrahlungsdauer in Sekunden.
• 3 die UV-induzierte Verklebung anhand eines Loop-Tack-Tests für die gemäß der Tabelle 7 hergestellten Polyurethanklebstoffe UV 11 und UV 15. Aufgetragen ist die Klebkraft in Newton in Abhängigkeit von der UV-Bestrahlungsdauer in Sekunden.
• 4 die UV-induzierte Verklebung anhand eines 180° Peel-Tests für die gemäß der Tabelle hergestellten Polyurethanklebstoffe UV 11 und UV 15. Aufgetragen ist die Klebkraft in Newton in Abhängigkeit von der UV-Bestrahlungsdauer in Sekunden.

Show it:

• 1 UV-induced bonding using a 180° peel test for polyurethane adhesives UV 10 to UV 14 produced according to Table 3. The adhesive strength is plotted in Newtons as a function of the UV irradiation time in seconds.
• 2 UV-induced bonding using a loop tack test for polyurethane adhesives UV 10 to UV 14 produced according to Table 3. The bond strength is plotted in Newtons as a function of the UV irradiation time in seconds.
• 3 UV-induced bonding using a loop tack test for the polyurethane adhesives UV 11 and UV 15 produced according to Table 7. The bond strength is plotted in Newtons as a function of the UV irradiation time in seconds.
• 4 UV-induced bonding using a 180° peel test for the polyurethane adhesives UV 11 and UV 15 produced according to the table. The adhesive strength is plotted in Newtons as a function of the UV irradiation time in seconds.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• US 5021507 A [0004]
• US5018337 [0005]
• WO 2016123418 A1 [0005]
• WO 0181495 A2 [0005]
• EP2022060648 [0006]

Claims (35)

A process for preparing a polymer composition comprising the steps of: a) combining: (i) a polyol or a prepolymer having terminal isocyanate (NCO) groups with (ii) an ethylenically unsaturated, non-active hydrogen-containing monomer having no moisture-reactive functional groups (monomer type A), and (iii) an ethylenically unsaturated, non-active hydrogen-containing monomer having a moisture-reactive functional group (monomer type B); (iv) an ethylenically unsaturated, non-active hydrogen-containing monomer having a radical photoinitiator group (monomer type C); b) polymerizing the mixture of step a. using a radical polymerization process with a chain transfer agent to obtain a low molecular weight polymer; c) optionally heating the mixture from step b) to a temperature of 100°C to 160°C for 10 to 60 minutes to partially crosslink the polyol with the low molecular weight polymer. Procedure according to Claim 1 , characterized in that the polyol is selected from the group consisting of polyester, polyether polyols such as polyethylene oxide or a polypropylene oxide, hydroxyl group-containing polycaprolactone, polyoxyalkene polyol, monosubstituted glycol ester, polythioether, polyamide, polyesteramide, polycarbonate, polyacetal, polyhydrocarbon polyol, polyacrylate polyol, polymethacrylate polyol, polyalcohol, bisphenol, polycarbonate polyol, polyhydroxy-functional fats and oils and mixtures thereof, wherein the polyol is preferably a polyether polyol with a molecular weight between 400 and 40,000 Da, a polyethylene oxide or a polypropylene glycol. Method according to at least one of the Claims 1 and 2 , characterized in that the monomer type A is selected from the group consisting of C1 to C12 esters of acrylic acid or methacrylic acid such as glycidyl acrylate, glycidyl methacrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, methyl methacrylate, ethyl methacrylate or n-butyl methacrylate, vinyl esters such as vinyl acetate or vinyl propionate, vinyl ethers, fumarates, maleates, styrenes, acrylonitriles, ethylenes, or mixtures thereof, wherein the monomer type A is preferably n-butyl methacrylate (n-BMA) or methyl methacrylate (MMA) or a mixture thereof. Process according to at least one of the preceding claims, characterized in that the monomer type B is selected from the group consisting of vinyl compounds, acrylates, methacrylates, fumarates, maleates, styrenes, acrylonitriles, ethylenes, or mixtures thereof, which have a moisture-reactive functional group, which is preferably a silane group. Procedure according to Claim 4 , characterized in that the monomer type B is selected from the group consisting of vinyltrichlorosilane, methylvinyldichlorosilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris(2methoxyethoxy)silane, vinyltriacetoxysilane, vinylmethyldiethoxysilane, vinyldimethylethoxysilane, vinylmethyldimethoxysilane, vinyldimethylmethoxysilane, vinylmethyldiacetoxysilane, vinyltriisopropoxysilane, vinyltriisopropenoxysilane, vinyltris(methylethylketoximino)silane, divinyltetramethyldisiloxane, tetravinyltetramethylcyclotetrasiloxane, 3-acryloxypropyldimethylmethoxysilane, 3-acryloxypropyldimethylethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-Methyacryloxypropylmethyldiethoxysilane, 3-Methyacryloxypropylmethyldimethoxysilane, 3-Methacryloxypropyltris(2methoxyethoxy)silane-, 4-(3-Trimethoxysilylpropyl)benzylstyrenesulfonate, allyltriethoxysilane, allyltrimethoxysilane and oligomers of these silanes, wherein the monomer type A is preferably methacryloxypropyltrimethoxysilane-. Process according to at least one of the preceding claims, characterized in that the monomer type C is a monomer with a radical photoinitiator group of type II, which is preferably a benzophenone group or an isopropylthioxanthone group and is particularly preferably selected from the group consisting of 4-methacryloyloxybenzophenone, 4-methacryloyloxyethoxybenzophenone, 4-methacryloyloxy-4'-methoxybenzophenone, 4-methacryloyloxyethoxy-4'-methoxybenzophenone, 4-methacryloyloxy-4'-bromobenzophenone, 4-acryloyloxyethoxy-4'-bromobenzophenone, 4-acryloyloxybenzophenone (ABP), 4-(2-acryloyloxy-ethoxy)benzophenone (AEBP), 4-(2-acryl-oyloxy-butoxy)benzophenone (ABBP), 4-(2-acryloyloxy-hexoxy)benzophenone (AHBP), and particularly preferably ABP or 4-methacryloyloxybenzophenone. Process according to at least one of the preceding claims, characterized in that in the radical polymerization process, a peroxide initiator or an azo initiator is used as initiator, which is preferably selected from the group consisting of dilauroyl peroxide, dibenzoyl peroxide, dimethyl 2,2'-azobisisobutyrate, di-(4-tert-butyl-cyclohexyl)-peroxydicarbonate and azobis(isobutyronitrile). Process according to at least one of the preceding claims, characterized in that the chain transfer agent is a halogen-organic compound, an unsaturated aromatic compound or a thiol, which is preferably selected from the group consisting of tetrachloromethane, 2,4-diphenyl-4-methyl-1-pentene, dodecyl mercaptan (DDM), lauryl mercaptan, thioglycolic acid, octyl thioglycolate, and thioglycerol, and particularly preferably dodecyl mercaptan. Process according to at least one of the preceding claims, characterized in that the polyol or the prepolymer with terminal NCO groups is present in an amount of 20 percent by weight to 90 percent by weight, preferably from 40 percent by weight to 80 percent by weight and particularly preferably from 50 percent by weight to 60 percent by weight, based on the total weight of the components polyol or prepolymer, monomer types A to C. Process according to at least one of the preceding claims, characterized in that the monomer type A is present in an amount of 30 percent by weight to 95 percent by weight, preferably from 50 percent by weight to 90 percent by weight and particularly preferably from 70 percent by weight to 85 percent by weight, based on the total weight of the monomer types A, B and C. Process according to at least one of the preceding claims, characterized in that the monomer type B is present in an amount of from 5 percent by weight to 70 percent by weight, preferably from 10 percent by weight to 50 percent by weight and particularly preferably from 15 percent by weight to 30 percent by weight, based on the total weight of the monomer types A, B and C. Process according to at least one of the preceding claims, characterized in that the monomer type C is present in an amount of from 0.1 percent by weight to 5.0 percent by weight, preferably from 0.2 percent by weight to 4.0 percent by weight and particularly preferably from 0.3 percent by weight to 3.0 percent by weight, based on the total weight of the monomer types A, B and C. Process according to at least one of the preceding claims, characterized in that the low molecular weight polymer has a number-average molecular weight of 3,000 to 200,000 g/mol, preferably from 5,000 to 100,000 g/mol and particularly preferably from 10,000 to 60,000 g/mol. Polymer composition prepared by a process according to at least one of the preceding claims. Polymer composition according to Claim 14 , characterized in that the polymer composition has a glass transition temperature of between -50 and 100 °C, preferably between -40 and 70 °C and particularly preferably between -30 and 60 °C. Polymer composition according to Claim 14 or 15 , characterized in that the polymer composition has a viscosity of 500 to 25,000 mPa.s, and preferably of 1,000 to 21,000 mPa.s, measured at 90°C. Polymer composition according to at least one of the Claims 14 until 16 , characterized in that it is free from solvents. Use of the polymer composition according to at least one of the Claims 14 until 17 as an adhesive, sealant or coating agent, wherein the polymer composition cures as a one-component composition with moisture and by increasing the temperature to more than 100°C. A process for producing a UV and moisture-curing polyurethane hot melt adhesive composition comprising the following steps: a) providing a polymer composition according to at least one of the Claims 14 until 17 ; b) adding sufficient polyisocyanate to achieve the desired isocyanate content and isocyanate index and polymerising using an addition polymerisation process; c) optionally adding an aminosilane or a mercaptosilane and converting to a silane-terminated polyurethane; d) irradiation with UV light for further crosslinking of the polymer. Procedure according to Claim 19 , characterized in that the polyisocyanate in step b) is selected from the group consisting of ethylene diisocyanate, ethylidene diisocyanate, propylene diisocyanate, butylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate (HDI), toluene diisocyanate, cyclopentylene-1,3-diisocyanate, cyclohexylene-1,4-diisocyanate, cyclohexylene-1,2-diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diisocyanatodicyclohexylmethane, 2,2-diphenylpropane-4,4'-diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, xylylene diisocyanate, 1,4-naphthylene diisocyanate, 1,5-naphthylene diisocyanate, diphenyl-4,4'-diisocyanate, Azobenzene-4,4'-diisocyanate, diphenylsulfone-4,4'-diisocyanate, dichlorohexamethylene diisocyanate, furfurylidene diisocyanate, 1-chlorobenzene-2,4-diisocyanate, 4,4',4''-triisocyanato-triphenylmethane, 1,3,5-triisocyanato-benzene, 2,4,6-triisocyanato-toluene and 4,4'-dimethyldiphenylmethane-2,2',5,5-tetraisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-bis(isocyanatomethyl)benzene, 1,3-bis(isocyanatomethyl)cyclohexane, polymeric diphenylmethane diisocyanate (PMDI), block diisocyanates and carbodiimide-modified polyisocyanates, and mixtures or precondensates thereof, such as HDI biuret or HDI cyanurate, wherein the polyisocyanate is preferably an aliphatic isocyanate is. Procedure according to Claim 19 or 20 , characterized in that the free isocyanate content is between 0 and 20%, preferably between 0 and 15% and particularly preferably between 0 and 10%. Method according to at least one of the Claims 19 until 21 , characterized in that the isocyanate index is between 0.5 and 10, preferably between 1 and 3 and particularly preferably between 1.5 and 2.5. UV and moisture-curing polyurethane hot melt adhesive composition prepared by a process according to at least one of the Claims 19 until 22 . UV and moisture curing polyurethane hot melt adhesive composition according to Claim 23 , characterized in that the composition has a viscosity of 10 mPas to 150,000 mPas at 120°C. Use of the UV and moisture-curing polyurethane hot melt adhesive composition according to Claim 23 or 24 as an adhesive, sealant or coating agent. Process for producing a 1K polyurethane adhesive comprising the following steps: a) providing a polymer composition according to at least one of the Claims 14 until 17 wherein instead of increasing the temperature in optional step b. the polymer is cooled to a temperature of 80 to 20°C; b) addition of a polyisocyanate to achieve a desired free isocyanate content and desired isocyanate index; c) optional cooling to a temperature of 80 to 20°C for a period of 0.5 to 5 hours. Procedure according to Claim 26 , characterized in that in step b) a polyisocyanate according to Claim 20 is used, wherein the polyisocyanate is preferably an aliphatic diisocyanate. Procedure according to Claim 26 or 27 , characterized in that the free isocyanate content is between 2 and 40%, preferably between 5 and 30% and particularly preferably between 10 and 20%. Method according to at least one of the Claims 26 until 28 , characterized in that the isocyanate index is between 1.5 and 20, preferably between 2 and 15 and particularly preferably between 4 and 10. 1K polyurethane adhesive produced by a process according to at least one of the Claims 26 until 29 . 1K polyurethane adhesive according to Claim 30 , characterized in that the 1K polyurethane adhesive has a viscosity of 5,000 to 25,000 mPa.s, and preferably of 6,000 to 21,000 mPa.s, measured at 90°C. Process for producing a 2K polyurethane adhesive comprising the following steps: a) providing a polymer composition according to at least one of the Claims 14 until 17 where instead of increasing the temperature in optional step b. the polymer is cooled to a temperature of 80 to 20°C and the polymer composition has epoxy groups, either introduced via one of the monomers A to C, which additionally have an epoxy group as a functional group or introduced via another ethylenically unsaturated monomer which does not contain active hydrogen and has an epoxy group as a functional group (monomer type D); b) addition of a polyisocyanate in order to achieve a desired free isocyanate content and desired isocyanate index; c) optional cooling to a temperature of 80 to 20°C for a period of 0.5 to 5 hours; for producing the first component of the 2K polyurethane adhesive with an epoxy-reactive monomer or prepolymer as the second component of the 2K polyurethane adhesive. Procedure according to Claim 33 , characterized in that the second component is an amine compound or a prepolymer with terminal isocyanate, hydroxy, thiol or amine groups. 2K polyurethane adhesive produced by a process according to Claims 32 or 33 . Use of a 1-component polyurethane adhesive according to Claim 30 or 31 or a 2K polyurethane adhesive according to Claim 34 as an adhesive, coating compound or sealant, in particular as a multi-purpose adhesive (household adhesive), assembly adhesive, construction adhesive, paper and packaging adhesive, film laminating adhesive, adhesive for ceramic and metallic materials, wood, glass, sandwich systems, textiles, reinforcing fabrics, materials in the aircraft, military or shipbuilding sectors.

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