Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Patent
1996-05-06
1999-12-28
Dawson, Robert
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
524405, 524437, 528 10, C08J 328
Patent
active
060082852
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a process for the production of compositions based on hydrolyzable silanes having epoxy groups, the compositions obtainable thereby, and the use of said compositions. Particularly, the present invention relates to a process for the production of such compositions for coatings and molded bodies having variable properties.
The prior art shows that it is possible to produce materials suitable for coating purposes via the sol-gel process from alkoxides such as, e.g., aluminum propylate or butylate, additionally using modified alkoxysilanes. Said processes are essentially characterized in that a mixture of the starting components can react to form a viscous liquid phase via a hydrolysis and condensation process. In said synthesis methods an organically modified inorganic basic skeleton is formed, which skeleton, in comparison to conventional polymers, is characterized by an increased surface hardness (scratch hardnesses using a Vickers diamond of 4 to 5 as compared to scratch hardnesses of conventional polymers of a magnitude of 1). However, a decisive disadvantage of said process is that due to the high reactivity of the aluminum-containing component no stable intermediate phases ("living system") can be achieved. Thus, the so-called pot life is limited (depending on the application purpose, between several hours and several days). The longer pot lives are not a consequence of the stability of the system but are to be considered merely a consequence of the application. This means that for different applications in the field of coatings, a relatively wide range of the varying property of the material (viscosity) may be tolerated. As already mentioned, in comparison to organic polymers, said layers have a relatively high hardness but are still relatively soft in comparison to inorganic materials. The reason therefor is that although the inorganic components in the system act strongly crosslinking, due to their very low size (in molecular dimensions, i.e., <1 nm), the mechanical properties such as, e.g., hardness and abrasion resistance, do not manifest themselves. The last mentioned properties are very pronounced in so-called filled polymers since in that case the particles have sizes of several .mu.m. However, the transparency of corresponding materials is lost and applications in the field of optics are not possible anymore. Although small particles of SiO.sub.2 (e.g., Aerosil.RTM., DEGUSSA) have successfully been employed for producing transparent layers having increased abrasion resistance, the abrasion resistances achieved with the employable low concentrations are similar to those of the systems mentioned above. The upper limit of the amount of filler is determined by the high surface reactivity of said small particles which results in agglomeration and intolerable increases in viscosity, respectively.
Thus, a first object of the present invention is to provide an organically modified inorganic system which shows a hardness significantly higher than that of the materials described in the prior art and which has a high optical transparency. Moreover, said system should also allow the preparation of stable intermediates which may be applied onto substrates and show properties constant with time as well as the adjustment of variable surface-physical and surface-chemical properties such as hydrophilic property or hydrophobic property in combination with oleophobic property.
In order to protect metallic surfaces against corrosion there are usually employed systems which develop passivating layers and are characterized in that they bond strongly to the surface, e.g., formation of mixed esters or oxides (Pb.sub.3 O.sub.4 on surfaces of iron, Cr.sub.2 O.sub.3 on surfaces of aluminum, etc.). By means of said surface compounds the reaction of water in combination with oxygen with the substrate material is prevented, said reaction resulting in a. permanent oxidation of the surface layer of the substrate (metal). The protective oxide layers (passivating layers) generally show the fu
REFERENCES:
patent: 4173490 (1979-11-01), Rotenberg et al.
patent: 4229228 (1980-10-01), Rotenberg et al.
patent: 4354013 (1982-10-01), Kimura
patent: 4522966 (1985-06-01), Funaki et al.
patent: 4904721 (1990-02-01), Hamaoka et al.
patent: 4933415 (1990-06-01), Shimizu et al.
patent: 5134191 (1992-07-01), Takarada et al.
patent: 5314947 (1994-05-01), Sawaragi
patent: 5367019 (1994-11-01), Sawaragi
patent: 5470910 (1995-11-01), Spanhel et al.
patent: 5595826 (1997-01-01), Gray et al.
Arpac Ertugrul
Geiter Elisabeth
Gerhard Volker
Kasemann Reiner
Schmidt Helmut
Aylward D.
Dawson Robert
Institut fuer Neue Materialien Gemeinnuetzige GmbH
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