DE3135672A1 - Use of low-viscosity self-curing mixtures for polyurethane interlayers in laminated panes - Google Patents

Abstract

The invention relates to the use of low-viscosity, readily pourable mixtures which are self-curing at low temperatures (below 50 DEG C) to give a polyurethane for interlayers in laminated security (safety) panes, in particular intruder-proof panes. The mixtures are characterised in that the viscosity of the individual components, and of the overall mixture, is less than 600 mPas/25 DEG C, and the mixture comprises: a) linear propylene oxide polyethers having a molecular weight in the range from 800 to 4000 (preferably from 1000 to 2500) which may optionally contain up to 15 mol % of ethylene oxide units, b) polyfunctional polypropylene oxide polyethers having a molecular weight in the range from 250 to 1250, preferably from 400 to 800, which may optionally contain up to 15 mol % of ethylene oxide units, c) cycloaliphatic diisocyanates, d) from 0.05 to 2.5 % by weight in the mixture of organotin catalysts, and optionally e) conventional additives, where the ratio between a) and b) is 1 : 1 to 16 : 1, and the NCO/OH ratio c)/a) + b) is from 0.8 to 1.3.

Description

Use of low-viscosity, self-hardening mixtures

genes for polyurethane interlayers in composite panes The invention relates to the use of low-viscosity, easily pourable and at low temperatures (below 500C) to a polyurethane self-curing mixture for intermediate layers for composite security panes, especially burglar-resistant panes.

A suitable method for building composite safety panes consists in that a mass is poured between two discs, which you then cross-linked by thermal action. Preferred materials for this purpose are polyurethane casting systems that lead to clear, transparent, hard or elastic Cure intermediate layers. Though many polyurethanes have been suggested for this purpose this technology was not widely used, as it was previously used for this purpose known polyurethane casting systems were difficult to process. They made highly viscous, sometimes even solid masses at room temperature, both during processing as well as high networking Temperatures required. Often was too the elasticity of the intermediate layer required for safety panes is not given. There has therefore been no lack of attempts to find casting systems that work with Forming mixtures that are liquid at room temperature, with the lowest possible temperature exposure to intermediate layers with the required mechanical and chemical properties Harden.

The state of the art for polyurethanes suitable for this purpose is z.a. reproduced by U.S. Patent 4,131,604 and U.S. Patent 4,131,606 in which Polyurethanes which are liquid at room temperature and curable at temperatures up to 500C to be discribed. These systems contain aliphatic isocyanate components Diisocyanates, in particular 4,4'-methylene-biscyclohexyl diisocyanate, and as a polyol component Mixtures of polycaprolactone diols and triols (US Pat. No. 4,131,605) or mixtures from linear polyalkylene ether glycols unbranched in the carbon chain, in particular Polytetramethylene ether glycols and polycaprolactone triols (U.S. Patent 4,131,605).

Curing is catalyzed by butylstannonic acid.

Even so, the mechanical properties of the polyurethane interlayers obtained are good, however, these systems still show some properties that are in need of improvement in terms of their manageability. Although the polyol blends at room temperature are described as liquid, they still show, even after mixing with the Isocyanate, relatively high viscosities on. This is particular disadvantageous in the production of thin intermediate layers, as it takes a very long time until the resin is poured in. The polyol components alone also show relative high viscosities, in the case of the linear polycaprolactone diols or the tetramethylene ether glycols they represent waxy solids even at room temperature. The increased viscosity is also particularly noticeable when prepolymers are produced which is a process variant that is often used in casting technology.

In DE-A 30 32 211, for the production of safety panes and composite panes with sound-absorbing properties, low-viscosity polyisocyanates and polyols which are low viscosity at room temperature are used. So are called isocyanates Biurets of hexamethylene diisocyanate or isophorone diisocyanate and as polyols among other things, linear or branched polypropylene oxide polyethers are used. the Interlayers made from these components are characterized by that the ratio of NCO to OH groups is a maximum of 0.6.

Although these intermediate layers are characterized by good sound insulation and splinter protection distinguish, their mechanical properties are nevertheless not good, since the after the products resulting from the curing process are either visco-elastic liquids or represent gel-like substances. The materials do not actually represent polyurethanes Meaning they are therefore themselves tigerely also as containing polyurethane groups Polyols ". If such panes are smashed with a heavy impact device, for example an ax, the intermediate layer offers no additional mechanical Resistance.

DE-B 1 219 187 (US Pat. No. 3,509,015) discloses a laminated safety glass described with a polyurethane intermediate layer, which consists of a (higher molecular weight) Diol, a diisocyanate and a curing agent with at least two groups that form urea or urethane bridges with isocyanates, is produced, thereby characterized in that the higher molecular weight diol is a polytetramethylene oxide diol with a Molecular weight is from about 550 to 3000 and the curing agent is a polyamine or is a polyol with at least 3 mobile H atoms together with a diol. Man represents the synthetic resin intermediate layer made of an NCO prepolymer (from polytetramethylene oxide diol and preferably toluene diisocyanate) mixed with the curing agent, heated again to about 65 - 950 in a vacuum and then pour this mixture between the plates. The multi-stage process, the viscous starting materials and the need to hot Pouring mixtures are very disadvantageous - apart from being the preferred ones aromatic diisocyanates result in easily discolored polyurethanes.

In GB-PS 1 401 986 glass laminates based on linear Polyethylene oxide ethers (molecular weight 500 to 5000), low molecular weight.; Ld roughly equi- equivalent amounts of diisocyanates as a casting compound (or as a prefabricated film) between panes of glass. These systems must but at relatively high mixing temperatures between sheets of glass heated to 146 "C be poured and kept at 146 "C for 24 hours to fully react.

It was therefore necessary to look for a technically advanced solution to provide a cast resin system that has the advantageous mechanical properties which combines polyurethanes with easy processability to form intermediate layers.

This object was achieved in that transparent panes from Glass and / or plastic with a low-viscosity, self-hardening, easily pourable one Mixture are poured, which from a) linear polypropylene oxide ethers b) multifunctional Polypropylene oxide ethers c) cycloaliphatic diisocyanates d) organotin catalysts and e) where appropriate, there are conventional additives and these are then added Temperatures of a maximum of 500C can cure automatically to form a polyurethane.

The invention relates to the use of easily pourable, low viscosity, at temperatures of maxi- times. 500C self-hardening Mixtures as intermediate layers for at least two glass and / or plastic panes existing laminated glass constructions made of diisocyanates, polyethers and, if necessary Catalysts, characterized in that mixtures with a viscosity of Individual components as well as the total mixture below 600 mPas / 250C, preferably below 300 mPas / 25 "C, from a) linear propylene oxide polyethers of the molecular weight range 800 to 4000 (preferably 1000 to 2500), which optionally up to 15 mol% of ethylene oxide units may contain, b) polyfunctional propylene oxide polyethers of molecular weight 250 to 1250, preferably 400 to 800, which optionally up to 15 mol% of ethylene oxide units may contain, c) cycloaliphatic diisocyanates, d) 0.05 to 2.5% by weight in the mixture of organotin catalysts and optionally e) customary additives, begins, the quantitative ratio of a) to b). 1: 1 to 16: 1, preferably 4: 1 to 12: 1, and the NCO / OH ratio c) / a) + b) 0.8-1.3, preferably 0.9 to 1.10 and particularly preferably 0.98-1.02.

The use of the polyurethane-forming mixtures according to the invention can then be done using the one-shot method by mixing the individual components Potting and allowing to harden.

However, the NCO prepolymer method is preferred, in which initially the Diisocyanate component with insufficient proportions of one polyether component, preferably of the linear polyether a), to form an NCO-containing polyurethane prepolymer is implemented, which then before its use with the remaining OH components is mixed and then allowed to harden. Are especially preferred in the prepolymer method mixing ratios in which the OH component and the NCO components are to be combined in a ratio of about 1: 1.

The advantageous viscosity of the mixtures according to the invention is surprising lower than with blends of tetramethylene oxide polyethers with the propylene oxide / polyethers are structurally closely related.

The low viscosity of the mixtures according to the invention also remains then obtained when working according to the prepolymer method. According to the invention preferred propylene oxide polyethers also show no tendency to absorb water, Water swelling or turbidity like the solyethylene oxide ethers.

Linear propylene oxide polyethers a) are those with a molecular weight from 800 to 4000, preferably from 1000 to 2500, are used.

The multifunctional propylene oxide polyethers c) are polyethers of a Molecular weight range from 250 to 1258, preferably from 400 to 800. Your Functionality can range from above 2.5 to about 6, but are trifunctional Propylene oxide polyether c) preferred. Examples of these preferred polyethers are Polyethers started on trimethylolpropane or glycerol and of the stated molecular weight range.

Both propylene oxide polyethers a) and b) also have such in question, in which up to 15 mol%, preferably up to only 10 mol% of the propylene oxide units are replaced by ethylene oxide. Again, such polyethers are preferred here where the ethylene oxide units are at the end of the chains.

Organotin catalysts such as tin (II) dialkanoates are used as catalysts such as tin-II-diacetate or tin-II-octoate and / or dialkyl-tin-IV-dialkanoate such as dimethyl and / or dibutyl tin IV dilaurate are used. These catalysts should be dosed so that a pot life of at least one hour at temperatures from 25 to 500C is possible if you use pot-pouring systems where the slices be poured by hand from a predetermined supply of the mixture. One uses about C.05 to 2, s Ge-b .-%, pre- preferably 0.05 to 1% by weight organotin catalysts. For hand-pouring systems, this is preferably less activated systems with 0.005 to 0.25% by weight of organotin catalysts are used, while machine casting systems use machine dosing of the individual components more highly catalyzed, faster reacting systems with possibly very short ones Pot life used. About 0.01 to 1.0% by weight of organotin are used for this purpose Catalysts used. A particularly preferred catalyst is tin-II-octoate.

Isophorone diisocyanate (IPDI), the dicyclohexylmethane diisocyanates as 4,4'- and / or 2,4'- and / or 2r2'-isomers or their isomer mixtures or conformers mixtures (stereoisomer mixtures) are preferred used, particularly preferably isophorone diisocyanate. Furthermore, mono- to tetra-C1-C4-alkyl derivatives of dicyclohexylmethane diisocyanates can be used, e.g. the 3,3'-dimethyl-dicyclohexylmethane-4,4'-diisocyanate.

The casting compounds according to the invention can also be combined with other customary Additives such as UV and IR absorbers, phenolic antioxidants, light stabilizers, other stabilizers or soluble dyes are provided.

The ratio of the linear propylene oxide polyethers a) to the polyfunctional ones Propylene oxide polyethers between about 1: 1 to 16: 1, preferred 4: 1 to 12: 1.

The NCO / OH ratio c) / a) + b) is about 0.8 to 1.3, preferably 0.9 to 1.1 and is particularly preferably between 0.98 to 1.02, i.e. about equivalent NCO / OH groups selected.

The hardness of the system (Shore A / 3 sec. Hardness) should be between 1 and 80 are, preferably 10 to 80. Shore A hardnesses 910 can also be achieved without the mechanical properties drop significantly. The harshness of the system can on the one hand adjusted by varying the proportions of linear and trifunctional polyether on the other hand, they can be increased by increasing the proportion of diisocyanate.

Mixtures which, after curing, form polyurethane interlayers Shore A hardness of 30 are particularly suitable for safety panes that using a plastic disc (preferably a polycarbonate disc), are constructed. Preferred thicknesses of the intermediate layer are then 1 to 4 mm.

Interlayers with Shore A hardnesses of 30 to 80 are particularly suitable for safety panes consisting of at least two panes of glass. The preferred one The thickness of the intermediate layer is then 3 to 6 mm.

The panes produced in this way are available as composite safety panes, can also be used as sound and heat insulating panes.

The following examples provide preferred embodiments of the invention again without limiting it.

Example 1 - Manufacture of an intermediate layer for one of two panes of glass Existing safety pane a) Manufactured using the one shot "process, 500 parts ) a propylene oxide polyether started on trimethylolpropane (OH number 375), 500 parts of a propylene oxide polyether (OH number 56) started on propylene oxide, 422 parts of isophorone diisocyanate and 0.06 part of tin (II) octoate are used at room temperature mixed. The mixture has a viscosity of 175 mPas / 200C.

After 10 minutes of evacuation at 0.1 mbar, the mixture is in a Layer thickness of 5 mm poured between two panes of glass and hardened at 500C. The hardening to a clear, colorless intermediate layer is completed after 4 hours. The Shore A hardness of the intermediate layer is 40.

b) Production by the prepolymer process Production of the NCO component: 289 parts of the linear polyether mentioned in Example 1a) are heated for 2 hours at 80.degree reacted with 422 parts of isophorone diisocyanate. After cooling to room temperature the viscosity of the NCO prepolymer is 78 mPas / 200C.

Parts by weight.

Production of the OH component: 500 parts of that mentioned in Example 1a) linear polyether with 211 parts of the trifunctional mentioned in Example 1a) Polyethers and 0.06 parts tin octoate mixed. The viscosity of the mixture is 600 mPas / 200C.

Production of the intermediate layer: Equal proportions of the NCO and the OH components are mixed at room temperature and evacuated. The viscosity of the Mixture is 210 mPas / 200C. The potting and curing takes place as below 1a).

Example 2 - Preparation of an intermediate layer for one from one Glass pane and a polycarbonate pane consisting of an intermediate layer based on the prepolymer process a) Production of the NCO component 184.5 parts of the example; 1a) mentioned linear Polyethers are reacted with 81 parts of isophorone diisocyanate at 80 ° C. for 2 hours. After cooling to room temperature, the viscosity of the NCO prepolymer is 263 mPas / 230C, b) representation of the OH component 50 parts of the trifunctional mentioned in 1a) Polyethers with 215.5 parts of the mentioned in 1a) ten difunctional Polyethers, as well as mixed with 0.12 parts of tin octoate. The viscosity is 412 mPas.

Both components are used in proportion to produce the intermediate layer Combined 1: 1 and evacuated.

The viscosity of this mixture is then 320 mPas at room temperature. The casting resin has a pot life of 3 hours. The hardening at 500C is after 6 hours. finished, at room temperature it takes two days. The polyurethane intermediate layer has a Shore A hardness / 3 sec.

from 15.

Example 3 Production of an Intermediate Layer Using the One Shot Process 100 parts of a propylene oxide ether started on propylene glycol (OH number 112), 20 parts of a propylene oxide polyether started on trimethylolpropane (OH number 550), 43.9 parts of isophorone diisocyanate and 0.1 part of tin octoate are used as in Example 1, processed into a polyurethane intermediate layer. Owns after mixing the casting resin has a viscosity of 136 mPas at 230C. The Shore A hardness / 3 seconds of the cured intermediate layer is 28.

Example 4 - Production of an intermediate layer according to the "one shot11 process The procedure described in Example 3 is repeated, but the linear polyether is replaced the OH number 112 through 200 Parts of an analogous polyether of the OH number 56. After mixing, the casting resin has a viscosity of 250 mPas / 230C. the Shore A hardness / 3 seconds of the hardened intermediate layer is 25.

Example 5 160 parts of a propylene glycol started propylene oxide polyether (OH number 56), 20. parts of a propylene oxide polyether started on trimethylolpropane (OH number 550), 38.2 parts of 4,4'-diisocyanatodicyclohexylmethane and 0.5 part of dibutyltin IV dilaurate are, as indicated in Example 1), processed into a polyurethane intermediate layer. The viscosity of the casting resin mixture is 256 mPas / 200C. The Shore A hardness / 3 Seconds of the cured intermediate layer is 11.

Example 6 200 parts of a propylene oxide polyether started on propylene glycol, which contains ethylene oxide units as end groups (ratio propylene oxide: ethylene oxide 95: 5, OH number 56), 200 parts of a propylene oxide polyether started on trimethylolpropane (OH number 550), 168.8 parts of isophorone diisocyanate and 0.1 part of tin octoate are, as indicated in Example 1, processed into a polyurethane intermediate layer. To After mixing, the casting resin has a viscosity of 165 mPas. The Shore A hardness / 3 Seconds of the cured intermediate layer is 65.

Example 7 - Comparative Example Those used in this example Polycaprolactone polyols correspond in molecular weight to those used in Example 3) Propylene oxide polyethers. The one-shot method is used.

100 parts of a polycaprolactone started on hexanediol (OH number 109), 20 parts of a trimethylolpropane-started polycaprolactone triol (OH number 41), 43 parts of isophorone diisocyanate and 0.1 part of tin octoate are as in Example 1 specified processed into a polyurethane intermediate layer. Owns after mixing the casting resin has a viscosity of 1128 mPas at 230C.

(The viscosity in Example 3) was only 136 mPas.) The Shore A hardness / 3 Sec. Of the cured intermediate layer is 41.

Example 8 - Comparative Example The one used in this example linear tetramethylene oxide polyethers and the trifunctional polycaprolactone triol correspond in molecular weight to the propylene oxide polyethers used in Example 4). The one-shot method is used.

200 parts of a tetramethylene polyether (OH number 57), 20 parts of a Polycaprolactone triol (OH number 541) started on trimethylolpropane, 43.9 parts Isophorone Diisocyanate and 0.1 part of tin octoate are as in Example 1) specified processed into a polyurethane intermediate layer. Owns after mixing the casting resin has a viscosity. of 2450 mPas at 230C (viscosity in example 4, 250 mPas). The Shore A hardness / 3 seconds of the cured intermediate layer is 33.

Example 9 - Comparative Examples This example shows that the relative high viscosities are retained even in the production of NCO prepolymers. Once again, OH components with identical molecular weights are used.

a) It becomes an NCO prepolymer from 40.5 parts of isophorone diisocyanate and 92.5 parts of a tetramethylene oxide polyether (OH number 57). the The viscosity of this prepolymer at 230 ° C. is 89 50 mPas. (Viscosity of the NCO prepolymer from Example 2a): 263 mPas.) b) An NCO prepolymer from isophorone diisocyanate and solidified with a linear polycaprolactone diol in the same molar ratio as in a) at room temperature to a waxy mass.

Claims (10)

Claims Use of easily pourable, low-viscosity, at temperatures of a maximum of 500 self-curing mixtures of diisocyanates, polyethers and optionally catalysts for intermediate layers with at least two glass and / or plastic panes of existing composite glass constructions, characterized in that that one mixes with a viscosity of the individual components as well as the total mixture below 600 mPas / 250C from a) linear propylene oxide polyethers of molecular weight 800 to 4000, which optionally contain up to 15 mol% of ethylene oxide units can, b) polyfunctional propylene oxide polyethers of molecular weight 250 to 1250, which can optionally contain up to 15 mol% of ethylene oxide units, c) cycloaliphatic diisocyanates, d) 0.05 to 2.5% by weight in the mixture of organotin Catalysts and, where appropriate, e) customary additives, sets in, where the ratio of a) to b) 1: 1 to 16: 1 and the NCO / OH ratio c) / a) + b) Is 0.8 to 1.3. 2. Use according to claim 1, characterized in that as linear Propylene oxide polyethers a) those with a molecular weight of 1000-2500 are used. 3. Use according to claim 1 and 2, characterized in that as multifunctional propylene oxide polyethers polyethers with a molecular weight of 400 to 800 can be used. 4. Use according to claim 1 to 3, characterized in that as polyfunctional propylene oxide polyethers b) trifunctional polyethers are used. 5. Use according to claim 1 to 4, characterized in that the The weight ratio of the polyethers a) to b) is 4: 1 to 12: 1. 6. Use according to claim 1 to 5, characterized in that as cycloaliphatic diisocyanates isophorone diisocyanate and dicyclohexylmethane-4,4'-diisocyanate can be used. 7. Use according to claim 1 to 6, characterized in that eas Diisocyanate is isophorone diisocyanate. 8. Use according to claim 1 to 7, characterized in that the NCO / OH ratio c) / a) + b) is 0.9 to 1.1. 9. Use according to claim 1 to 8, characterized in that as Organotin catalysts 0.01 to 1 wt .-% tin (II) octoate is used. 10. Use according to claim 1 to 9, characterized in that the mixture has Shore A / 3 sec. hardness between 10 and 80 after it has hardened.