Process for producing an isocyanate-terminated prepolymer

Abstract

The present invention relates to an isocyanate-terminated prepolymer obtainable by the process according to the invention, and to the use of the prepolymer obtained by the process according to the invention or of the prepolymer obtainable by the process according to the invention for the production of an adhesive film or of a shaped body. The invention also provides the process for producing the adhesive film and the adhesive film obtainable by this process.

Description

[0001] Process for producing an isocyanate-terminated prepolymer

[0002] The present invention relates to an isocyanate -terminated prepolymer obtainable by the process according to the invention, and to the use of the prepolymer obtained by the process according to the invention or of the prepolymer obtainable by the process according to the invention for the production of an adhesive film or of a shaped body. The invention also provides the process for producing the adhesive film and the adhesive film obtainable by this process.

[0003] EP0147588A1 discloses self-adhesive sheet-like structures, consisting of at least one support layer and at least one adhesive layer based on polyurethane gel. The sheet-like structures can be obtained by coating a very wide variety of support materials with a reaction mixture that consists of di- and / or polyisocyanates and an excess amount of high molecular weight polyols, and subsequent curing thereof, and can be used for example as a skin-compatible adhesive plaster for medical purposes or as an adhesive for industrial uses.

[0004] EP2436380 Al describes a plaster material which is mainly applied to the wound region of the skin, wherein the plaster material comprises a support material having a water-vapour permeability of at least 3000 g / m2- day and a polyurethane-based adhesive layer having a water-vapour permeability of 5000 g / m2- day.

[0005] WO9743328A1 describes hydrophilic polyurethane gel compositions and foams thereof, the use of the polyurethane gel compositions for pressure-distributing, in particular self-adhesive polyurethane (foam) gels thereof, and the use of the polyurethane gel compositions for self-adhesive and pressuredistributing materials and adhesive layers.

[0006] Skin-friendly, breathable adhesives for applications on the skin already exist on the market. However, these were developed in such a way that they can be stuck onto fresh wounds and therefore do not have good adhesive strength, or have none at all, when wet. They are particularly suitable for bedridden patients or patients with particularly sensitive skin who do not have a particularly high level of mobility (no sport, workouts, sauna sessions, etc.), i.e. who do not produce a lot of sweat or bathe / shower often, which limits the wearing time of the adhesive. The adhesives mentioned can be worn only poorly for long periods in such circumstances, since the desired moisture sensitivity (no sticking to wounds) causes the adhesives to lose their adhesive strength and detach from the skin in the case of relatively heavy sweating or intensive showering or bathing. At the same time, the adhesives mentioned, which are all two-component systems, are produced in a highly asymmetrical mixing ratio (approx. 9:1 to 11:1 according to proportions by weight), which places particular demands on the accuracy of the metering devices to be used and on the pumps and valves used on the mixer in order to avoid backflow of the main component into the line of the minor component (due to the higher pressure) and mixing errors. Furthermore, homogeneous mixing is difficult with such asymmetric mixing ratios. This requires costly and complex mixers having long mixing sections, which can lead to a high cleaning requirement for the mixers. The object of the present application was to provide an improved process for producing plaster materials based on a polyurethane-based adhesive film, where the adhesive film has not only a high level of breathability and a long wearing time but also improved adhesion when wet in comparison with polyurethane-based adhesive films described above. The intention here is for the polyol used for the production of the adhesive film, or specifically the isocyanate (prepolymer) component, to be producible via a process that is comparably simple with respect to the prior art.

[0007] Surprisingly, it has now been found that the above-mentioned objects are achieved by a process for producing an isocyanate-terminated prepolymer (A) comprising the reaction of an isocyanate group - reactive compound (B) with a polyisocyanate (C) and a component (D), wherein component (D) is a C-C double bond-containing monoalcohol having at least 8, preferably at least 10 and particularly preferably at least 12 carbon atoms in the molecule.

[0008] The invention also provides an isocyanate-terminated prepolymer (A) obtainable by the process according to the invention, and the use of the prepolymer (A) obtained by the process according to the invention or of the prepolymer (A) obtainable by the process according to the invention for the production of an adhesive film (H) or of a shaped body.

[0009] The invention is detailed below, where it is possible to combine the embodiments according to the invention with one another as desired provided that the opposite is not apparent from the technical context.

[0010] Prepolymer (A)

[0011] In one embodiment of the invention, the isocyanate-terminated prepolymer (A) has a C-C double bond content of 0.2% by weight to 3.9% by weight, preferably of 0.5% by weight to 3.4% by weight and particularly preferably of 1.0% by weight to 2.9% by weight, where the proportion by weight of the double bond content is the ratio of the -CH=CH- double bond unit(s) (26 g / mol) based on the molecular weight of the prepolymer (A) and can be experimentally determined by means of proton resonance spectroscopy known to those skilled in the art.

[0012] In one embodiment of the invention, the isocyanate-terminated prepolymer (A) has an isocyanate proportion of 1% by weight to 30% by weight, preferably of 5% by weight to 25% by weight, particularly preferably 7% by weight to 20% by weight.

[0013] In one embodiment of the invention, the isocyanate-terminated prepolymer (A) has viscosity of 10 mPa-s to 5000 mPa-s, preferably of 100 mPa-s to 2000 mPa-s, where the viscosity was determined in accordance with DIN 53019 at 23°C and a shear rate of 50 / s.

[0014] Isocyanate group-reactive compound (B)

[0015] In one embodiment of the process according to the invention, the isocyanate group-reactive compound (B) is a polyether polyol (B-l), a polyetherester polyol (B-2) and / or a polyester polyol (B-3), preferably a poly ether polyol (B-l). In one embodiment of the process according to the invention, the isocyanate group-reactive compound (B), preferably the polyether polyol (B-l), has a calculated functionality of 2 to 8, preferably of 2 to 6 and particularly preferably of 2 to 4.

[0016] In one embodiment of the process according to the invention, the isocyanate group-reactive compound (B) is the polyether polyol (B-l) and the polyether polyol (B-l) is obtainable by reaction of an H- functional starter compound (E) with an alkylene oxide (F) in the presence of a catalyst (G), preferably a basic catalyst.

[0017] In one embodiment of the process according to the invention, the isocyanate group-reactive compound

[0018] (B) has a molar mass of 2 g / mol to 2500 g / mol, preferably of 50 g / mol to 1500 g / mol and particularly preferably of 100 g / mol to 1000 g / mol, where the molar mass was determined by means of the method disclosed in the experimental section.

[0019] Polyisocyanate (C)

[0020] In one embodiment of the process according to the invention, the polyisocyanate (C) is at least one compound having a molar mass of 140 g / mol to 600 g / mol containing aliphatic, cycloaliphatic, araliphatic and / or aromatically bonded isocyanate groups.

[0021] In a preferred embodiment of the process according to the invention, the polyisocyanate (C) is one or more compounds and is selected from the group consisting of 1,5-diisocyanatopentane (pentamethylene diisocyanate, PDI), 1,6-diisocyanatohexane (hexamethylene diisocyanate, HDI), 1- isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 2,4'- and 4,4'-diisocyanatodicyclohexylmethane (H12-MDI), and 1,3- and l,4-bis(isocyanatomethyl)benzene (xylylene diisocyanate, XDI), 1,3- and l,4-bis(2-isocyanatopropan-2-yl)benzene (tetramethylxylylene diisocyanate, TMXDI), 2,2'-, 2,4'- and 4,4'-diisocyanatodiphenylmethane (MDI), 3,3'- dimethyldiphenylmethane 4,4'-diisocyanate, 4,4'-diisocyanatodiphenylethane, 1,5- diisocyanatonaphthalene (NDI).

[0022] In a particularly preferred embodiment of the process according to the invention, the polyisocyanate

[0023] (C) is 1,5-diisocyanatopentane (pentamethylene diisocyanate, PDI) and / or 1,6-diisocyanatohexane (hexamethylene diisocyanate, HDI).

[0024] In a very particularly preferred embodiment of the process according to the invention, the polyisocyanate (C) is 1,6-diisocyanatohexane (hexamethylene diisocyanate, HDI).

[0025] In the context of the present invention, polyisocyanates are compounds having at least two isocyanate groups. Preference is given to using polyisocyanates having two isocyanate groups, which are also referred to as diisocyanates.

[0026] In one embodiment of the process according to the invention, the production of the prepolymer (A) is carried out at an NCO index of >1.0 to 20, preferably of 1.5 to 15, particularly preferably of 2.0 to 10. The NCO index corresponds here to the ratio of the free NCO groups of the polyisocyanate (B) to the NCO-reactive groups of the isocyanate group-reactive compound (B) and the hydroxyl groups of the C-C double bond-containing monoalcohol.

[0027] Component (D)

[0028] According to the invention, component (D) is a C-C double bond-containing monoalcohol having at least 8, preferably at least 10, particularly preferably at least 12 carbon atoms in the molecule, the C-C double bond-containing monoalcohol also being able to be referred to as an unsaturated fatty acid alcohol.

[0029] In one embodiment of the process according to the invention, the C-C double bond-containing monoalcohol of component (D) has at most 28, preferably at most 24 and particularly preferably at most 22 carbon atoms in the molecule.

[0030] In a preferred embodiment of the process according to the invention, the C-C double bond-containing monoalcohol of component (D) has from 8 to 28, preferably from 10 to 24 and particularly preferably from 12 to 22 carbon atoms in the molecule. For example, cis-9-octadecen-l-ol (oleyl alcohol) has the molecular formula CisFheO as molecular formula and has 18 carbon atoms in the molecule.

[0031] In one embodiment of the process according to the invention, component (D) is one or more compounds and is selected from the group consisting of cis-9-hexadecen-l-ol (palmitoleyl alcohol), cis-9-octadecen-l-ol (oleyl alcohol), trans-9-octadecen-l-ol (elaidyl alcohol), cis-l l-octadecen-l-ol, cis,cis-9,12-octadecadien-l-ol (linoleyl alcohol) and 6,9,12-octadecatrien-l-ol (y-linolenyl alcohol), preferably cis-9-hexadecen-l-ol (palmitoleyl alcohol) and cis-9-octadecen-l-ol (oleyl alcohol) and particularly preferably cis-9-octadecen-l-ol (oleyl alcohol).

[0032] In one embodiment of the process according to the invention, the C-C double bonds of the monoalcohol of component (D) are cis C-C double bonds. Examples of monoalcohols having cis C-C double bonds are cis-9-hexadecen-l-ol (palmitoleyl alcohol) and cis-9-octadecen-l-ol (oleyl alcohol). Cis C-C double bonds are technically advantageous in this case, since they reduce a tendency of the prepolymer (A) to crystallize and thus reduce the melting point, which facilitates processing of the prepolymer in further reactions.

[0033] In one embodiment of the process according to the invention, the calculated proportion by mass of component (D) is from 5% by weight to 80% by weight, preferably from 10% by weight to 70% by weight and particularly 20% by weight to 60% by weight based on the sum total of the masses used of the isocyanate group-reactive compound (B), preferably of the poly ether polyol (B-l), and of component (D).

[0034] H-functional starter compound (E)

[0035] In one embodiment of the process according to the invention, the H-functional starter compound (E) is one or more compounds and is selected from the group consisting of propane- 1,2-diol, propylene glycol, ethylene glycol, diethylene glycol, dipropylene glycol, butane- 1,2-diol, butane- 1,3 -diol, butane- 1,4-diol, hexanediol, pentanediol, 3-methylpentane-l,5-diol, glycerol, trimethylolpropane, pentaerythritol, sorbitol, sucrose, hydroquinone, catechol, resorcinol, and 1,3, 5 -trihydroxybenzene, preferably propane- 1,2-diol, propylene glycol, ethylene glycol, diethylene glycol, dipropylene glycol, butane- 1,2-diol, butane- 1,3 -diol, butane- 1,4-diol, hexanediol, pentanediol, and 3-methylpentane-l,5- diol.

[0036] In one embodiment of the process according to the invention, the H-functional starter compound (E) has a calculated functionality of 2 to 8, preferably of 2 to 6 and particularly preferably of 2 to 4.

[0037] Alkylene oxide (F)

[0038] In one embodiment of the process according to the invention, the alkylene oxide (F) is propylene oxide and / or ethylene oxide, preferably propylene oxide.

[0039] Catalyst (G)

[0040] In one embodiment of the process according to the invention, the catalyst (G) is a basic catalyst, preferably an alkali metal hydroxide such as lithium hydroxide, potassium hydroxide or sodium hydroxide, preferably potassium hydroxide.

[0041] Adhesive film (H)

[0042] The invention further provides a process for producing an adhesive film (H) comprising the reaction a) of the prepolymer (A) obtained by the process according to the invention or of the prepolymer (A) obtainable by the process according to the invention with b) an isocyanate group-reactive compound (I) c) in the presence of a catalyst (J) d) optionally in the presence of auxiliaries (K).

[0043] The invention also provides an adhesive film (H) obtainable by the process according to the invention. In one embodiment of the process according to the invention, the production of an adhesive film (H) is carried out at an NCO index of less than 1.0, preferably of 0.3 to 0.8 and particularly preferably in the range from 0.4 to 0.7.

[0044] Isocyanate group-reactive compound (I)

[0045] In one embodiment of the process according to the invention, the isocyanate group-reactive compound (I) is a polyether polyol (1-1), a polyetherester polyol (1-2) and / or a polyester polyol (1-3), preferably a poly ether polyol (1-1). The poly ether polyol (1-1) is technically advantageous on account of the improved breathability of the resulting adhesive layer (H) or of the plaster material (P).

[0046] In one embodiment of the process according to the invention, the isocyanate group-reactive compound (I), preferably the polyether polyol (1-1), has a molar mass of 2 g / mol to 2500 g / mol, where the molar mass was determined by means of the method disclosed in the experimental section. In one embodiment of the process according to the invention, the isocyanate group-reactive compound (I), preferably the poly ether polyol (1-1), has a calculated functionality of more than 2 to 8, preferably of 3 to 6 and particularly preferably of 3.5 to 6.

[0047] Polyether polyol (1-1)

[0048] In one embodiment of the process according to the invention, the isocyanate group-reactive compound (I) is a polyether polyol (1-1), the polyether polyol (1-1) being technically advantageous on account of the improved breathability of the resulting adhesive layer (H) or of the plaster material (P).

[0049] In a preferred embodiment of the process according to the invention, the isocyanate group -reactive compound (I) is the polyether polyol (1-1) and the polyether polyol (1-1) is obtainable by reaction of an H-functional starter compound (L) with an alkylene oxide (M) in the presence of a catalyst (N).

[0050] In a preferred embodiment of the process according to the invention, the production of the polyether polyol (1-1) comprises the following steps:

[0051] I) reacting the H-functional starter compound (L) with a first partial amount of the alkylene oxide (M) in the presence of the catalyst (N), preferably the alkali metal hydroxide, to form an intermediate (O),

[0052] II) reacting the intermediate (O) with a second partial amount of the alkylene oxide (M), wherein the first partial amount is propylene oxide or a propylene oxide -ethylene oxide mixture, preferably propylene oxide, wherein the second partial amount is ethylene oxide or a propylene oxide-ethylene oxide mixture, preferably ethylene oxide, and wherein the first partial amount of the alkylene oxide is 70% by weight to 90% by weight based on the sum total of the first and second partial amount of the alkylene oxide (M).

[0053] Polyetherester polyol (1-2)

[0054] In an alternative, less preferred embodiment of the process according to the invention, the isocyanate group-reactive compound (I) is a polyetherester polyol (1-2), where the polyetherester polyol (1-2) is obtainable by reaction of an H-functional starter compound (L) with an alkylene oxide (M) in the presence of a catalyst (N) in the presence of a polycarboxylic acid or a cyclic carboxylic anhydride such as succinic anhydride or maleic anhydride.

[0055] Polyester polyol (1-3)

[0056] In a third, less preferred embodiment of the process according to the invention, the isocyanate groupreactive compound (I) is a polyester polyol (1-3), where the polyester polyol (1-3) is obtainable by reaction of an organic dicarboxylic acid and / or a cyclic carboxylic anhydride with polyhydric alcohols, which polyhydric alcohols are preferably diols. The polyester polyols are produced by processes known to those skilled in the art, such as polycondensation or polyaddition reactions. Catalyst (J)

[0057] Suitable as catalysts (J) are those of the type known per se from polyurethane chemistry, for example tertiary amines, such as triethylamine, N-tetramethylethylenediamine, l,4-diazabicyclo[2.2.2]octane,

[0058] N,N-dimethylbenzylamine, N-methyl-N'-dimethylaminoethylpiperazine, pentamethyldiethylenetriamine, or else Mannich bases known as catalysts and formed from secondary amines, such as dimethylamine, and aldehydes (formaldehyde) or ketones (acetone) and phenols, also silaamines having carbon-silicon bonds, for example 2,2,4-trimethyl-2-silamorpholine and 1,3- diethylaminomethyltetramethyldisiloxane. According to the invention, organic metal compounds, in particular organic bismuth, tin, zinc or iron compounds, may also be used as catalysts. Examples of organic tin compounds are tin(II) acetate, tin(II) ethylhexoate and tin(IV) compounds, for example dibutyltin dichloride, dibutyltin dilaurate, dibutyltin maleate.

[0059] In addition, also suitable are organic bismuth compounds such as soluble bismuth(III) carboxylates based on linear, branched, saturated or unsaturated carboxylic acids having 2 to 18, preferably 6 to 18, carbon atoms. Preference is given to bismuth(III) salts of branched saturated carboxylic acids with tertiary carboxyl groups, such as 2,2-dimethyloctanoic acid (bismuth neodecanoate).

[0060] In one embodiment of the process according to the invention, the catalyst (J) is used in amounts of

[0061] O.01% to 0.3%, in particular 0.03% to 0.15% by weight based on the isocyanate group -reactive compound (I), preferably the polyether polyol (1-1).

[0062] Auxiliaries (K)

[0063] In one embodiment of the process according to the invention, it is possible to add auxiliaries (K) such as antioxidants, fillers, dyes, thickeners, extenders, resins.

[0064] Useful antioxidants (stabilizers) for the adhesive film (H) according to the invention are in particular sterically hindered phenolic stabilizers, such as BHT (2,6-di-tert-butyl-4-methylphenol), Vulkanox BKF (2,2'-methylenebis(6-tert-butyl-4-methylphenol), Irganox 1010 (pentaerythritol tetrakis(3-(3,5- di-tert-butyl-4-hydroxyphenyl)propionate), Irganox 1076 (octadecyl-3-(3,5-di-tert-butyl-4- hydroxyphenyl)propionate), Irganox 1135 (benzenepropanoic acid, 3,5-bis (l,l-dimethyl-ethyl)-4- hydroxy-C7-C9 branched alkyl esters), Irganox 1330 (l,3,5-trimethyl-2,4,6-tris(3',5'-di-tert-butyl-4'- hydroxybenzyl)benzene), Irganox 1520 (2-methyl-4,6-bis[(octylthio)methyl]phenol) and / or tocopherols. Preference is given to using those of the a-tocopherol (vitamin E) type. Further stabilizers are mentioned for example in Ullmann (Vol. A3, p. 91-111; Vol. A20, p. 461-479; Vol. A23, p. 381- 391).

[0065] The stabilizing properties of the phenolic stabilizers can be further improved by addition of organically substituted sulfides or disulfides, such as Irganox PS800 (dilauryl 3,3 -thiodipropionate) or dioctyl didecyl disulfide. Combinations of the phenolic types with one another are also possible. The addition of the listed stabilizers in particular makes it possible to produce, from the adhesive film (H) according to the invention, products that can also be sterilized by means of high-energy y radiation. This is of paramount importance especially in the production of medical articles, such as wound care products (including first aid dressings, plasters or tamponades).

[0066] The antioxidants are preferably used in amounts of 0.15% to 5% by weight, in particular 0.2% to 2.0% by weight, based on the isocyanate group-reactive compound (I), preferably the polyether polyol (1-1). In the case of antioxidant mixtures, such as those mentioned above, the antioxidants are preferably used in amounts of 0.05% to 0.5% by weight per individual substance, based on the isocyanate groupreactive compound (I), preferably the polyether polyol (1-1).

[0067] According to the invention, the additives customary for polyurethanes, such as fillers, dyes, thickeners, extenders, resins, etc., may be added to the adhesive film (H), preferably up to 100% by weight, particularly preferably up to 20% by weight and particularly preferably up to 10% by weight based on the isocyanate group-reactive compound (I), preferably the poly ether polyol (1-1). Fillers used are additives known per se from polyurethane chemistry, such as inorganic- or organic-based short fibres. Inorganic fillers that may be mentioned in particular are powders composed of zinc oxide and titanium dioxide, and short fibres, such as glass fibres having a length of 0.1-1 mm. Organic fillers that may be listed in particular are swellable powders and fibres having a fibre length > 0.01 mm, for example based on polyacrylic acids and salts thereof or others, such as those mentioned for example in Absorbent Polymer Technology (BrannonPeppas, Harland, ELSEVIER, Amsterdam-Oxford-New York-Tokyo, 1990, p. 9-22), and materials used as textile fibres, such as polyesters or polyamide fibres. Dyes or pigments should in particular be understood to mean those used in food, packaging or cosmetics. Liquid extenders or resins are in particular polymeric vinyl compounds, poly acrylates and other copolymers customary in adhesive technology, which can influence adhesive properties.

[0068] H-functional starter compound (L)

[0069] In one embodiment of the process according to the invention, the H-functional starter compound (L) has a calculated functionality of more than 2 to 8, preferably of 3 to 6 and particularly preferably of 3.5 to 6.

[0070] In one embodiment of the process according to the invention, the H-functional starter compound (L) is one or more compounds and is selected from the group consisting of sorbitol, sucrose, glycerol, trimethylolpropane and pentaerythritol, preferably glycerol, trimethylolpropane and pentaerythritol.

[0071] Alkylene oxide (M)

[0072] In one embodiment of the process according to the invention, the alkylene oxide (M) is ethylene oxide and / or propylene oxide. Catalyst (N)

[0073] In one embodiment of the process according to the invention, the catalyst (N) is a basic catalyst, preferably an alkali metal hydroxide such as lithium hydroxide, potassium hydroxide or sodium hydroxide, preferably potassium hydroxide.

[0074] Plaster material (P)

[0075] The invention further provides a process for producing a plaster material (P) comprising the application of the adhesive film (H) obtained by the process according to the invention or of the prepolymer (A) according to the invention to a support material (Q).

[0076] The invention further provides a plaster material (P) obtainable by the process according to the invention.

[0077] Support material ( Q)

[0078] In one embodiment of the process according to the invention, the support material (Q) consists of a plastics film based on for example polyurethane (PUR) or polyvinyl chloride (PVC), of a foam film based on for example PVC, PUR or polyethylene or preferably textile fibre nonwovens based on for example viscose fibres, and woven fabrics based on for example artificial silk or warp-knitted stretch fabrics based on for example PUR / poly amide yarn mixtures.

[0079] In a first embodiment, the invention relates to a process for producing an isocyanate -terminated prepolymer (A) comprising the reaction of an isocyanate group -reactive compound (B) with a polyisocyanate (C) and a component (D), wherein component (D) is a C-C double bond-containing monoalcohol having at least 8, preferably at least 10, particularly preferably at least 12 carbon atoms in the molecule.

[0080] In a second embodiment, the invention relates to a process according to the first embodiment, wherein the prepolymer (A) has a C-C double bond content of 0.2% by weight to 3.9% by weight, preferably of 0.5% by weight to 3.4% by weight and particularly preferably of 1.0% by weight to 2.9% by weight, where the proportion by weight of the double bond content is the ratio of the -CH=CH- double bond unit(s) (26 g / mol) based on the molecular weight of the prepolymer (A) and can be experimentally determined by means of proton resonance spectroscopy known to those skilled in the art.

[0081] In a third embodiment, the invention relates to a process according to the first or second embodiment, wherein the prepolymer (A) has an isocyanate proportion of 1% by weight to 30% by weight, preferably of 5% by weight to 25% by weight, particularly preferably 7% by weight to 20% by weight. In a fourth embodiment, the invention relates to a process according to any of the first to third embodiments, wherein the isocyanate group-reactive compound (B) is a polyether polyol (B-l), a polyetherester polyol (B-2) and / or a polyester polyol (B-3), preferably a polyether polyol (B-l).

[0082] In a fifth embodiment, the invention relates to a process according to any of the first to fourth embodiments, wherein the isocyanate group-reactive compound (B), preferably the polyether polyol (B-l), has a calculated functionality of 2 to 8, preferably of 2 to 6 and particularly preferably of 2 to 4. In a sixth embodiment, the invention relates to a process according to any of the first to fifth embodiments, wherein the isocyanate group-reactive compound (B) is the polyether polyol (B-l) and the poly ether polyol (B-l) is obtainable by reaction of an H-functional starter compound (E) with an alkylene oxide (F) in the presence of a catalyst (G), preferably a basic catalyst.

[0083] In a seventh embodiment, the invention relates to a process according to any of the first to sixth embodiments, wherein the isocyanate group-reactive compound (B) has a molar mass of 2 g / mol to 2500 g / mol, preferably of 50 g / mol to 1500 g / mol and particularly preferably of 100 g / mol to 1000 g / mol, where the molar mass was determined by means of the method disclosed in the experimental section.

[0084] In an eighth embodiment, the invention relates to a process according to any of the first to seventh embodiments, wherein the polyisocyanate (C) is at least one compound having a molar mass of 140 g / mol to 600 g / mol containing aliphatic, cycloaliphatic, araliphatic and / or aromatically bonded isocyanate groups.

[0085] In a ninth embodiment, the invention relates to a process according to any of the first to eighth embodiments, wherein the polyisocyanate (C) is one or more compounds and is selected from the group consisting of 1,5-diisocyanatopentane (pentamethylene diisocyanate, PDI), 1,6-diisocyanatohexane (hexamethylene diisocyanate, HDI), l-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 2,4'- and 4,4'-diisocyanatodicyclohexylmethane (H12-MDI), and 1,3- and l,4-bis(isocyanatomethyl)benzene (xylylene diisocyanate, XDI), 1,3- and l,4-bis(2- isocyanatopropan-2-yl)benzene (tetramethylxylylene diisocyanate, TMXDI), 2,2'-, 2,4'- and 4,4'- diisocyanatodiphenylmethane (MDI), 3, 3 '-dimethyldiphenylmethane 4,4'-diisocyanate, 4,4'- diisocyanatodiphenylethane, 1,5-diisocyanatonaphthalene (NDI), preferably 1,5-diisocyanatopentane (pentamethylene diisocyanate, PDI) and / or 1,6-diisocyanatohexane (hexamethylene diisocyanate, HDI) and particularly preferably 1,6-diisocyanatohexane (hexamethylene diisocyanate, HDI).

[0086] In a tenth embodiment, the invention relates to a process according to any of the first to ninth embodiments, wherein the production of the prepolymer (A) is carried out at an NCO index of >1.0 to 20, preferably of 1.5 to 15, particularly preferably of 2.0 to 10.

[0087] In an eleventh embodiment, the invention relates to a process according to any of the first to tenth embodiments, wherein the C-C double bond-containing monoalcohol of component (D) has at most 28, preferably at most 24 and particularly preferably at most 22 carbon atoms in the molecule. In a twelfth embodiment, the invention relates to a process according to any of the first to eleventh embodiments, wherein the C-C double bond-containing monoalcohol of component (D) has from 8 to 28, preferably from 10 to 24 and particularly preferably from 12 to 22 carbon atoms in the molecule. In a thirteenth embodiment, the invention relates to a process according to any of the first to twelfth embodiments, wherein the C-C double bond-containing monoalcohol of component (D) is one or more compounds and is selected from the group consisting of cis-9-hexadecen-l-ol, cis-9-octadecen-l-ol, trans-9-octadecen-l-ol, cis-l l-octadecen-l-ol, cis,cis-9,12-octadecadien-l-ol and 6,9,12- octadecatrien-l-ol, preferably cis-9-hexadecen-l-ol and cis-9-octadecen-l-ol and particularly preferably cis-9-octadecen-l-ol.

[0088] In a fourteenth embodiment, the invention relates to a process according to any of the first to thirteenth embodiments, wherein the C-C double bonds of the monoalcohol of component (D) are cis C-C double bonds.

[0089] In a fifteenth embodiment, the invention relates to a process according to any of the first to fourteenth embodiments, wherein the calculated proportion by mass of component (D) is from 5% by weight to 80% by weight, preferably from 10% by weight to 70% by weight and particularly 20% by weight to 60% by weight based on the sum total of the masses used of the isocyanate group-reactive compound (B), preferably of the poly ether polyol (B-l), and of component (D).

[0090] In a sixteenth embodiment, the invention relates to a process according to any of the sixth to fifteenth embodiments, wherein the H-functional starter compound (E) is one or more compounds and is selected from the group consisting of propane- 1,2-diol, propylene glycol, ethylene glycol, diethylene glycol, dipropylene glycol, butane- 1,2-diol, butane-l,3-diol, butane- 1,4-diol, hexanediol, pentanediol, 3-methylpentane-l,5-diol, glycerol, trimethylolpropane, pentaerythritol, sorbitol, sucrose, hydroquinone, catechol, resorcinol, and 1,3,5-trihydroxybenzene, preferably propane- 1,2-diol, propylene glycol, ethylene glycol, diethylene glycol, dipropylene glycol, butane- 1,2-diol, butane- 1,3- diol, butane- 1,4-diol, hexanediol, pentanediol, and 3-methylpentane-l,5-diol.

[0091] In a seventeenth embodiment, the invention relates to a process according to any of the sixth to fifteenth embodiments, wherein the H-functional starter compound (E) has a calculated functionality of 2 to 8, preferably of 2 to 6 and particularly preferably of 2 to 4.

[0092] In an eighteenth embodiment, the invention relates to a process according to any of the sixth to seventeenth embodiments, wherein the alkylene oxide (F) is propylene oxide and / or ethylene oxide, preferably propylene oxide.

[0093] In a nineteenth embodiment, the invention relates to a process according to any of the sixth to eighteenth embodiments, wherein the catalyst (G) is a basic catalyst, preferably an alkali metal hydroxide such as lithium hydroxide, potassium hydroxide or sodium hydroxide, preferably potassium hydroxide.

[0094] Advantageously, the process according to the invention also encompasses a purification step such as distillation to obtain an isocyanate-terminated prepolymer (A) with a low monomer content, such as a residual monomer content of 1 wt% or less of monomer, preferably 0.5 wt% or less, more preferably 0.3 wt% or less, based on the weight of prepolymer (A). More specifically short-path distillation can be applied, in one or more evaporation steps.

[0095] In a twentieth embodiment, the invention relates to an isocyanate-terminated prepolymer (A) obtainable by the process according to any of the first to nineteenth embodiments.

[0096] In a twenty-first embodiment, the invention relates to an isocyanate-terminated prepolymer (A) according to the twentieth embodiment having a calculated C-C double bond content of 0.2% by weight to 3.9% by weight, preferably of 0.5% by weight to 3.4% by weight and particularly preferably of 1.0% by weight to 2.9% by weight.

[0097] In a twenty-second embodiment, the invention relates to an isocyanate-terminated prepolymer (A) according to the twentieth or twenty-first embodiment having a calculated isocyanate proportion of 1 % by weight to 30% by weight, preferably of 5% by weight to 25% by weight, particularly preferably 7% by weight to 20% by weight.

[0098] In a twenty-third embodiment, the invention relates to an isocyanate-terminated prepolymer (A) according to any of the twentieth to twenty-second embodiments, wherein the isocyanate-terminated prepolymer (A) has viscosity of 10 mPa-s to 5000 mPa- s, preferably of 100 mPa-s to 2000 mPa-s, where the viscosity was determined in accordance with DIN 53019 at 23°C and a shear rate of 50 / s. Advantageously, the isocyanate-terminated prepolymer (A) according to the invention has a residual monomer content of 1 wt% or less of monomer, preferably 0.5 wt% or less, more preferably 0.3 wt% or less, based on the weight of prepolymer (A).

[0099] In a twenty-fourth embodiment, the invention relates to a process for producing an adhesive film (H) comprising the reaction a) of the prepolymer (A) obtained by the process according to any of the first to nineteenth embodiments or of the prepolymer (A) according to any of the twentieth to twenty-third embodiments with b) an isocyanate group-reactive compound (I) c) in the presence of a catalyst (J) d) optionally in the presence of auxiliaries (K).

[0100] In a twenty-fifth embodiment, the invention relates to a process according to the twenty-fourth embodiment, wherein the production of an adhesive film (H) is carried out at an NCO index of less than 1.0, preferably of 0.3 to 0.8 and particularly preferably in the range from 0.4 to 0.7.

[0101] In a twenty-sixth embodiment, the invention relates to a process according to the twenty-fourth or twenty-fifth embodiment, wherein the isocyanate group-reactive compound (I) is a polyether polyol (1-1), a polyetherester polyol (1-2) and / or a polyester polyol (1-3), preferably a polyether polyol (1-1).

[0102] In a twenty-seventh embodiment, the invention relates to a process according to any of the twentyfourth to twenty-sixth embodiments, wherein the isocyanate group-reactive compound (I), preferably the polyether polyol (1-1), has a molar mass of 2 g / mol to 2500 g / mol, where the molar mass was determined by means of the method disclosed in the experimental section.

[0103] In a twenty-eighth embodiment, the invention relates to a process according to any of the twenty-fourth to twenty-seventh embodiments, wherein the isocyanate group-reactive compound (I), preferably the poly ether polyol (1-1), has a calculated functionality of more than 2 to 8, preferably of 3 to 6 and particularly preferably of 3.5 to 6.

[0104] In a twenty-nineth embodiment, the invention relates to a process according to any of the twenty-fourth to twenty-eighth embodiments, wherein the isocyanate group-reactive compound (I) is a polyether polyol (1-1) and the poly ether polyol (1-1) is obtainable by reaction of an H-functional starter compound

[0105] (L) with an alkylene oxide (M) in the presence of a catalyst (N).

[0106] In a thirtieth embodiment, the invention relates to a process according to any of the twenty-fourth to twenty-nineth embodiments, wherein the production of the polyether polyol (1-1) comprises the following steps:

[0107] I) reacting the H-functional starter compound (L) with a first partial amount of the alkylene oxide

[0108] (M) in the presence of the catalyst (N), preferably the alkali metal hydroxide, to form an intermediate (O),

[0109] II) reacting the intermediate (O) with a second partial amount of the alkylene oxide (M), wherein the first partial amount is propylene oxide or a propylene oxide -ethylene oxide mixture, preferably propylene oxide, wherein the second partial amount is ethylene oxide or a propylene oxide -ethylene oxide mixture, preferably ethylene oxide, and wherein the first partial amount of the alkylene oxide is 70% by weight to 90% by weight based on the sum total of the first and second partial amount of the alkylene oxide (M).

[0110] In a thirty-first embodiment, the invention relates to a process according to the thirtieth embodiment, wherein the H-functional starter compound (L) has a calculated functionality of more than 2 to 8, preferably of 3 to 6 and particularly preferably of 3.5 to 6.

[0111] In a thirty-second embodiment, the invention relates to a process according to the thirtieth or thirty- first embodiment, wherein the H-functional starter compound (L) is one or more compounds and is selected from the group consisting of sorbitol, sucrose, glycerol, trimethylolpropane and pentaerythritol, preferably glycerol, trimethylolpropane and pentaerythritol.

[0112] In a thirty-third embodiment, the invention relates to a process according to any of the thirtieth to thirty- second embodiments, wherein the catalyst (N) is a basic catalyst, preferably an alkali metal hydroxide such as lithium hydroxide, potassium hydroxide or sodium hydroxide, preferably potassium hydroxide. In a thirty-fourth embodiment, the invention relates to an adhesive film (H) obtainable by the process of any of the twenty-fourth to thirty-third embodiments.

[0113] In a thirty-fifth embodiment, the invention relates to a process for producing a plaster material (P) comprising the application of the adhesive film (H) obtained by the process according to any of the twenty-fourth to thirty-third embodiments or of the adhesive film (H) according to the thirty-fourth embodiment to a support material (Q).

[0114] In a thirty-sixth embodiment, the invention relates to a process according to the thirty-fifth embodiment, wherein the support material (Q) consists of a plastics film based on for example polyurethane (PUR) or polyvinyl chloride (PVC), of a foam film based on for example PVC, PUR or polyethylene or preferably textile fibre non wo vens based on for example viscose fibres, and woven fabrics based on for example artificial silk or warp-knitted stretch fabrics based on for example PUR / polyamide yarn mixtures.

[0115] In a thirty-seventh embodiment, the invention relates to a plaster material (P) obtainable by the process according to the thirty-fifth or thirty-sixth embodiment.

[0116] In a thirty-eighth embodiment, the invention relates to the use of the prepolymer (A) obtained by a process according to any of the first to nineteenth embodiments or of the prepolymer (A) according to any of the twentieth to twenty-third embodiments for the production of an adhesive film (H) or of a shaped body.

[0117] Examples

[0118] Substances used

[0119] Polyisocyanate (C)

[0120] Hexamethylene diisocyanate (HDI) Desmodur H, Covestro Deutschland AG

[0121] Component (D) cis-9-Octadecen-l-ol HD-Ocenol 90 / 95 V, Pharchem

[0122] Isocyanate group-reactive compound (I)

[0123] Polyol (1-1) Poly ether polyol based on a tetrafunctional starter compound, Baymedix

[0124] AR602, Covestro Deutschland AG, OH number 35 mg KOH / g

[0125] Catalyst (J)

[0126] Bismuth neodecanoate Coscat 83, Dow Chemical

[0127] Auxiliaries (K)

[0128] Irganox 1135 Benzenepropanoic acid, 3,5-bis (l,l-dimethyl-ethyl)-4-hydroxy-C7-C9 branched alkyl esters, BASF

[0129] Byk-378 (Polyol mixture), polyether-modified dimethylpoly siloxane

[0130] Tocopherol 2H-l-benzopyran-6-ol, Sigma Aldrich

[0131] Characterization methods

[0132] Determination of viscosity

[0133] The viscosity was determined using a rotational viscometer (Physica MCR 51 , manufacturer: Anton Paar) in accordance with the method of DIN 53018 at 23 °C and a shear rate of 50 / s.

[0134] OH number

[0135] The OH numbers were determined in accordance with the method of DIN 53240.

[0136] Climatic chamber test

[0137] A coarse-pore beaten foam is attached to 2 cm-wide metal strips using a double-sided adhesive tape. The adhesive film to be investigated is then stuck onto the beaten foam. For a double determination, in each case two prepared test specimens are stored at 23°C@50%rH (50% relative humidity, dry measurement) and 40°C@90%rH (90% relative humidity, wet measurement) for 24 h. The force is then determined using a spring balance for a 180° peel. The force is reported in N / 20 mm. The wet and dry measurements are compared in order to determine the decrease in adhesive strength when wet. The decrease in adhesive strength is 50%. Production of the prepolymers (A):

[0138] Example 1: Prepolymer 1 (according to the invention)

[0139] 898.8 g of hexamethylene diisocyanate (HDI) was initially charged at 80°C and a mixture of 176.8 g of a difunctional polypropylene oxide having a molar mass of 218 g / mol (OH number 515 mg KOH / g, started from propane- 1,2-diol) and 144.3 g of cis-9-octadecen-l-ol was added dropwise over the course of 1 h. Subsequently, stirring was continued until an NCO content of 29.5% was reached and 0.6 g of tocopherol was added. The excess HDI was removed by short -path distillation at 130°C in a preliminary evaporator and 120°C in a main evaporator and a pressure of 0.7 mbar. A prepolymer having an NCO content of 11.7% and a viscosity of 839 mPas was obtained.

[0140] Example 2: Prepolymer 2 (comparative)

[0141] NCO-terminated prepolymer based on hexamethylene diisocyanate (HDI) and a difunctional polypropylene oxide having a molar mass of 218 g / mol (OH number 515 mg KOH / g, started from propane- 1,2-diol), the NCO-terminated prepolymer having an NCO content of 12.3% by weight and being sold under the trade name Baymedix AP501.

[0142] Production of the adhesive films (H)

[0143] Example 3: Adhesive film production (according to the invention):

[0144] To produce a masterbatch, 100 g of polyol (1-1), 2 g of Coscat 83 and 8 g of Irganox 1135 are mixed using a SpeedMixer for 30 seconds at a rotational speed of 3500 min ’. 5.5 g of the masterbatch mixture is mixed with a further 94.5 g of polyol (1-1) and 1 g of Byk-378 (polyol mixture) in the SpeedMixer. Before the addition and mixing in the SpeedMixer with the polyol mixture and 16.6 g of the prepolymer (A) according to Example 1 is performed, the prepolymer (A) according to Example 1 is stored at 80°C for 2 hours, in order to obtain a clear and transparent liquid.

[0145] After the mixing process, the reactive mixture is poured onto a silicone release paper from Cotek RB 120 / 1. The layer thickness is adjusted using a 100 pm doctor blade. The subsequent lamination of the film is performed with a Platilon VPT9101 film.

[0146] Example 4: Adhesive film production (comparative):

[0147] To produce a masterbatch, 100 g of polyol (1-1), 2 g of Coscat 83 and 8 g of Irganox 1135 are mixed using a SpeedMixer for 30 seconds at a rotational speed of 3500 min ’. 5.5 g of the masterbatch mixture is mixed with a further 94.5 g of polyol (1-1) and 1 g of Byk-378 (polyol mixture) in the SpeedMixer. Finally, 9.9 g of the prepolymer according to Comparative Example 2 is added to the polyol mixture using the SpeedMixer. After the mixing process, the reactive mixture is poured onto a silicone release paper from Cotek RB 120 / 1. The layer thickness is adjusted using a 100 pm doctor blade. The subsequent lamination of the film is performed with a Platilon VPT9101 film.

[0148] Table 1:

[0149] The results show that when using an adhesive film (H) according to Example 3, which was produced using a prepolymer (A) according to Example 1 that is in accordance with the invention, the decrease in adhesive force in the climatic chamber test is significantly lower than when using the adhesive film (H) according to Example 4 based on the non-inventive prepolymer (A) according to Example 2.

[0150] Example 5: Adhesive film production (comparative):

[0151] 100 g of of the prepolymer (A) according to Example 1, 0.1 g of Coscat 83 and 1g Byk-378 are mixed using a SpeedMixer for 30 seconds at a rotational speed of 3500 min ’. After the mixing process, the reactive mixture is poured out on a silicone release paper from Cotek RB 120 / 1 . The layer thickness is adjusted by a 100pm film applicator. The subsequent lamination of the adhesive film is carried out with a Platilon VPT9101 film.

[0152] After 24 hours the film was still greasy and not cured.

[0153] It was not possible to carry out a climate chamber test because no film was formed.

[0154] This example shows that the omission of the isocyanate -reactive compound (I) in the process for producing an adhesive film (H) will not lead to the formation of an adhesive film.

[0155] Example 6: Adhesive film production with separate addition of component (D) (comparative):

[0156] To produce a masterbatch, 100g of polyol (1-1), 2g Coscat 83 and 8g Irganox 1135 are mixed. 5.5g of the masterbatch mixture are mixed with 94.5g of polyol (I- 1), 3.7g cis-9-octadecen-l-ol and 1g Byk- 378. Finally, the addition and mixing of 11.2g of the prepolymer (A) according to Comparative Example 2 is done. All mixing steps are done by speed mixer for 30 seconds and at 3500 rpm. After the mixing process, the reactive mixture is poured out on a silicone release paper from Cotek RB 120 / 1. The layer thickness is adjusted by a 100pm film applicator. The subsequent lamination of the adhesive film is carried out with a Platilon VPT9101 film. The decrease in adhesive force in the climate chamber test is 100%, which demonstrates that separate addition of a C-C double bond-containing monoalcohol only after the making of the isocyanate- terminated prepolymer (A) will not lead to a suitable adhesive film.

Claims

Claims1. Process for producing an isocyanate-terminated prepolymer (A) comprising the reaction of an isocyanate group-reactive compound (B) with a polyisocyanate (C) and a component (D), wherein component (D) is a C-C double bond-containing monoalcohol having at least 8, preferably at least 10 and particularly preferably at least 12 carbon atoms in the molecule.

2. Process according to Claim 1, wherein the C-C double bond-containing monoalcohol of component (D) has at most 28, preferably at most 24 and particularly preferably at most 22 carbon atoms in the molecule.

3. Process according to Claim 1 or 2, wherein component (D) is one or more compounds and is selected from the group consisting of cis-9-hexadecen-l-ol, cis-9-octadecen-l-ol, trans-9- octadecen-l-ol, cis-l l-octadecen-l-ol, cis,cis-9,12-octadecadien-l-ol and 6,9,12- octadecatrien-l-ol, preferably cis-9-hexadecen-l-ol and cis-9-octadecen-l-ol and particularly preferably cis-9-octadecen-l-ol.

4. Process according to any of Claims 1 to 3, wherein the C-C double bonds of the monoalcohol of component (D) are cis C-C double bonds.

5. Process according to any of Claims 1 to 4, wherein the calculated proportion by mass of component (D) is from 5% by weight to 80% by weight, preferably from 10% by weight to 70% by weight and particularly 20% by weight to 60% by weight based on the sum total of the masses used of the isocyanate group-reactive compound (B), preferably of the polyether polyol (B-l), and of component (D).

6. Isocyanate-terminated prepolymer (A) obtainable by the process according to any of Claims 1 to 5.

7. Isocyanate-terminated prepolymer (A) according to Claim 6 having a calculated C-C double bond content of 0.2% by weight to 3.9% by weight, preferably of 0.5% by weight to 3.4% by weight and particularly preferably of 1.0% by weight to 2.9% by weight.

8. Process for producing an adhesive film (H) comprising the reaction a) of the prepolymer (A) obtained by the process according to any of Claims 1 to 5 or of the prepolymer (A) according to Claim 6 or 7 with b) an isocyanate group-reactive compound (I) c) in the presence of a catalyst (J)d) optionally in the presence of auxiliaries (K).

9. Process according to Claim 8, wherein the isocyanate group-reactive compound (I) is a poly ether polyol (1-1) and the poly ether polyol (1-1) is obtainable by reaction of an H- functional starter compound (L) with an alkylene oxide (M) in the presence of a catalyst (N).

10. Process according to Claim 8 or 9, wherein the isocyanate group-reactive compound (I), preferably the poly ether polyol (1-1), has a calculated functionality of more than 2 to 8, preferably of 3 to 6 and particularly preferably of 3.5 to 6.

11. Process according to any of Claims 8 to 10, wherein the production of the poly ether polyol (I- 1) comprises the following steps:I) reacting the H-functional starter compound (L) with a first partial amount of the alkylene oxide (M) in the presence of the catalyst (N), preferably the alkali metal hydroxide, to form an intermediate (O),II) reacting the intermediate (O) with a second partial amount of the alkylene oxide (M), wherein the first partial amount is propylene oxide or a propylene oxide-ethylene oxide mixture, preferably propylene oxide, wherein the second partial amount is ethylene oxide or a propylene oxide-ethylene oxide mixture, preferably ethylene oxide, and wherein the first partial amount of the alkylene oxide is 70% by weight to 90% by weight based on the sum total of the first and second partial amount of the alkylene oxide (M).

12. Adhesive film (H) obtainable preferably by the process according to any of Claims 8 to 11.

13. Use of the prepolymer (A) obtained by the process according to any of Claims 1 to 5 or of the prepolymer (A) according to Claim 6 or 7 for the production of an adhesive film (H) or of a shaped body.

14. Process for producing a plaster material (P) comprising the application of the adhesive film (H) obtained by the process according to any of Claims 8 to 11 or of the adhesive film (H) according to Claim 12 to a support material (Q).

15. Plaster material (P) obtainable by the process according to Claim 14.

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