Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Patent
1997-05-30
1998-11-10
Michl, Paul R.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
525127, 525130, 525399, C08K 529
Patent
active
058345426
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to impact-resistant thermoplastic molding materials containing thereof and assistants,
The present invention furthermore relates to the use of such molding materials for the production of moldings of any kind and to the moldings obtainable therefrom.
Polyoxymethylenes which contain thermoplastic polyurethanes as impact modifiers are disclosed, inter alia, in EP-A 116 456.
The blending of thermoplastic polyurethanes with other polymers is disclosed in: different thermoplastics and filler (eg. polyurethane+polystyrene or ABS+glass beads) polyurethane, carbon black and metal sulfide powder and further thermoplastics, such as polyester thermoplastics (eg. polyamide, PET, polyolefin or polyurethane) and crystalline thermoplastics (eg. polystyrene, PVC or ABS).
In some applications, for example sanitary engineering, high requirements are also set for stability to hydrolysis, to hot water and to damp humid conditions, in addition to good impact strength. Polymers such as polyoxymethylenes are known to be stable and resistant to conventional organic solvents or hot water, but TPU is not. Particularly during continuous use, such moldings composed of POM/TPU blend compositions tend to yellow and become brittle.
In EP-A 117 748, polycarbodiimides having a certain molecular weight and sterically hindered groups were incorporated into such blends for better stabilization of POM/TPU blends. The disadvantage of blends stabilized in this manner is the isocyanate elimination which occurs during processing. The tendency to yellow is not significantly changed by the addition of these polycarbodiimides since such moldings still have a yellowish coloration.
German Laid-Open Application DE-OS 3,703,232 described POM/TPU molding materials which are stabilized with alkaline earth metal salts of aliphatic, preferably hydroxyl-containing aliphatic monobasic to tribasic carboxylic acids. However, these additives are not suitable for increasing the stability of the molding materials to hydrolysis. Furthermore, the tendency to discoloration is high.
GB-B 993 600 discloses POM/TPU mixtures which contain polyamides and certain monocarbodiimides as stabilizers. However, the rigidity of such moldings is unsatisfactory. During processing, these monocarbodiimides moreover have the disadvantage that they are exuded, ie. coatings are formed in the injection mold.
U.S. Pat. No. 4,640,949 discloses POM/TPU mixtures which contain aromatic polycarbodiimides as stabilizers.
In the more recent European Patent Application No. 94108216.6 (prior art according to Art. 54(3)), novel carbodiimides for TPU were proposed.
It is an object of the present invention to provide impact-resistant thermoplastic molding materials which exhibit the following advantages: corresponding specimens on hot storage corresponding specimens in hot water heat and also combined heat and moisture processing (toxicologically unobjectionable) greatest extent possible (for polycarbodiimides).
We have found that this object is achieved by the molding materials defined at the outset, wherein the thermoplastic polyurethane B) contains from 0.05 to 10% by weight, based on B), of a carbodiimide of the formula I: ##STR2## where R is identical or different and is selected from the group consisting of --NCO--, --NHCONHR.sup.1 --, --NHCONR.sup.1 R.sup.2 -- and --NHCOOR.sup.3 -- radicals, where or aralkyl radical and
Preferred embodiments are described in the subclaims.
The novel molding materials contain, as component A), from 10 to 99.5, preferably from 15 to 99, in particular from 20 to 95, % by weight of a polyoxymethylene homo- or copolymer.
Such polymers are known per se to a person skilled in the art and are described in the literature.
Very generally, these polymers contain at least 50 mol % of repeating units --CH.sub.2 O-- in the polymer main chain.
The homopolymers are generally prepared by polymerizing formaldehyde or trioxane, preferably in the presence of suitable catalysts.
For the purposes of the present invention, preferred components A) are po
REFERENCES:
patent: 4410596 (1983-10-01), Matsumoto et al.
patent: 4640949 (1987-02-01), Wagman
patent: 4819572 (1989-04-01), Scholl et al.
patent: 4845161 (1989-07-01), Richardson
Abstract J 5 6136-838.
Abstract J 5 8209-527.
Abstract J 5 7085-994.
Abstract J 6 3126-709.
Eichenauer Ulrich
Kielhorn-Bayer Sabine
Lehrich Friedhelm
BASF - Aktiengesellschaft
Michl Paul R.
LandOfFree
Impact-resistant thermoplastic molding materials does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Impact-resistant thermoplastic molding materials, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Impact-resistant thermoplastic molding materials will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1517451