Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From reactant having at least one -n=c=x group as well as...
Reexamination Certificate
1999-11-15
2004-08-03
Sergent, Rabon (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From reactant having at least one -n=c=x group as well as...
C528S076000, C528S077000
Reexamination Certificate
active
06770730
ABSTRACT:
The present invention relates to a compact veneer based on a reaction mixture comprising
a) isocyanate,
b) as compounds which are reactive toward isocyanates, a mixture (b1) comprising:
b11) from 15 to 90% by weight, preferably from 50 to 80% by weight, based on the weight of the mixture (b1), of at least one polyether polyalcohol having a molecular weight of from 400 to 6000, preferably from 1000 to 4000 and a mean functionality of from 1.5 to 3 and based on hydroxyl-containing initiator substances and propylene oxide and also, if desired, ethylene oxide,
b12) from 0 to 20% by weight, preferably from 0 to 10% by weight, based on the weight of the mixture (b1), of at least one polyether polyalcohol having a molecular weight of from 400 to 6000, preferably from 400 to 4000, and a mean functionality of from 1.5 to 3 and based on amino-containing initiator substances and propylene oxide and also, if desired, ethylene oxide,
b13) from 0 to 35% by weight, preferably from 2 to 15% by weight, based on the weight of the mixture (b1), of at least one polyether polyalcohol having a molecular weight of from 150 to 7000 and a mean functionality of from 2.1 to 5, preferably from 3.1 to 5,
b14) from 0 to 30% by weight, preferably from 10 to 25% by weight, based on the weight of the mixture (b1), of at least one bifunctional chain extender, plus, if desired,
c) catalysts and/or
d) auxiliaries and/or additives,
where the sum of the percentages by weight of the components (b11), (b12), (b13) and (b14) is preferably 100% by weight.
Furthermore, the invention relates to a process for producing moldings comprising foamed polyisocyanate polyaddition products and a compact veneer according to the present invention as a skin adhering thereto, such moldings and their use.
Polyisocyanate polyaddition products, usually polyurethanes and/or polyisocyanurates, obtainable by reacting isocyanates with compounds which are reactive toward isocyanates are generally known. A particular embodiment of these products is moldings which have a synthetic skin based on such products laminated onto them. These moldings are usually composite components comprising essentially this veneer and usually a flexible polyurethane foam and possibly a rigid support. These moldings are used, inter alia, in automobile construction where they are employed, for example, as seats, dashboards consoles, glove compartments or as interior or exterior trim, but they are also used in shipbuilding and the construction of vehicles for use in the agricultural and the building and construction sectors.
These moldings are generally produced by laying a thermoplastic film in the foam shell and subsequently deep-drawing this film in the foam shell or by spraying a heat-curable one-component or cold-curing two-component polyurethane liquid film into the appropriate mold and subsequently backfoaming the film with a polyurethane foam in the presence of a rigid support, so that the foam provides a connection between the film and the support. Disadvantages of the use of the deep-drawn film are the scrap resulting from projecting parts of film, the limitations imposed on the design by deep drawing, since surface features such as graining are changed in the stretched zones, and the layer thickness determined by the film. The disadvantages of producing the veneer by spraying the liquid polyurethane systems, as described, for example, in EP-A 275 009 and EP-A 303 305, are the relatively long curing time, the application problems in the case of tight undercuts, the layer thickness which is particularly difficult to set in the case of edges and aerosol formation by the reactive starting components in the workplace. The application of a one-component polyurethane system as described in EP 0275009 also has disadvantages such as an extremely high mold temperature and comparatively little possible variation as regards mechanics and curing behavior of the skin.
It is an object of the present invention to develop veneers having excellent optical and mechanical properties, for example a uniform structure, excellent feel, a high strength and/or high extensibility together with great design freedom. These veneers should, in particular, be suitable for the economical production of moldings which preferably consist of a composite with flexible foams and, if desired, rigid supports and can be used, for example, in automobile construction. Furthermore, the veneer and foam being made of the same material would be an advantage in terms of future recycling or disposal. A further object is to develop reaction mixtures which can be processed without aerosol formation to produce these veneers based on polyisocyanate polyaddition products. The reaction mixture should make it possible to produce the veneer in a mold without a spraying step.
We have found that this object is achieved by the veneers described at the outset.
For the purposes of the present invention, the expression veneers refers to sheet-like, compact bodies which usually have a thickness of from 0.1 to 5 mm. The veneers, which are generally known as (synthetic) skins, usually serve as covering layers of moldings. According to the present invention, preference is given to moldings, also referred to as composite elements, which comprise foamed polyisocyanate polyaddition products, in particular flexible polyurethane foams, and a veneer according to the present invention as a skin adhering thereto. The moldings particularly preferably further comprise rigid supports, for example compact stiffening elements or construction elements, e.g. on the basis of steel, aluminum or customary plastics such as polyurethane.
These moldings according to the present invention are used, inter alia, as seats, dashboards, consoles, glove compartments or interior or exterior trim in, for example, automobile construction. These products comprising the moldings of the present invention have the following advantages:
high design freedom
uniform grain
excellent mechanical properties
excellent feel
little production scrap
lightfast and colored products can be produced without problems
impermeability to water
As regards the starting components present in the reaction mixture according to the present invention, the following may be said, with the examples given for the components (a), (c) and (d) also applying to the polyisocyanate polyaddition products, particularly preferably flexible polyurethane foams, preferably present in the moldings:
As isocyanates (a), it is possible to use generally known (cyclo)aliphatic and/or aromatic polyisocyanates. Particularly suitable isocyanates for producing the composite elements of the present invention are aromatic diisocyanates, preferably diphenylmethane diisocyanate (MDI) and/or tolylene diisocyanate (TDI), and/or polyisocyanates such as polyphenyl polymethylene polyisocyanates. The isocyanates can be used in the form of the pure compound, in mixtures and/or in modified form, for example in the form of uretdiones, isocyanurates, allophanates or biurets, preferably in the form of reaction products, known as isocyanate prepolymers, containing urethane and isocyanate groups.
As compounds (b) which are reactive toward isocyanates, use is made, according to the present invention, of the novel mixture (b1) described at the outset.
The component (b11) can be prepared, for example, by generally known alkoxylation of bifunctional and trifunctional initiator substances, for example ethylene glycol and/or propylene glycol or trimethylolpropane or glycerol, using known alkylene oxides, e.g. ethylene oxide, propylene oxide and/or butylene oxide. The alkylene oxides can be added onto the initiator substance or substances in mixtures or blockwise, e.g. the component (b11) can be end-capped by ethylene oxide.
The component (b12) differs from the component (b11) essentially in the use of the initiator substance. Initiator substances used are ones containing primary and/or secondary amino groups, for example 2-(diethylamino)ethylamine, diethylamino-4-aminopentane, diethylaminopropylamine and/or dimethylaminopropylam
Bartz Thomas
Knoblauch Georg
Roche Peter
BASF - Aktiengesellschaft
Borrego Fernando A.
Sergent Rabon
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