Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Patent
1995-06-30
1997-12-16
Zitomer, Fred
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
525258, 525284, 525301, 525302, 525308, 525309, 525310, 525312, 525313, 525316, 525319, C08F25502, C08F25504, C08F25506, C08F25508
Patent
active
056986378
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a method for the functionalization of polyolefins in molten state so that the obtained product, as such or melt-mixed with other polyolefins, will achieve good adhesion with other polymers, metals, or other inorganic materials. The invention relates both to a method for the preparation of functional polyolefins and to multi-layer products and mixtures of a functional polymer with other polymers and/or an inorganic substance, prepared by using the method.
The grafting of a functional unsaturated monomer onto polyolefins, in particular onto polypropylene, can be carried out by at least three different technologies.
The grafting can be carried out at a temperature below the melting temperature of the polymer, for example in a fluid-bed reactor. In this case, a very long reaction time can be selected, thus making possible a high conversion of the monomer. Any ungrafted monomer can be removed by vacuum stripping (U.S. Pat. No. 3,414,551).
Another prior known method is based on solution or suspension grating, in which the polymer is grafted in a hydrocarbon solvent, in general at a temperature of 80.degree.-160.degree. C. Any unreacted monomer can be rinsed off with alkali-containing water (EP 202 921, U.S. Pat. No. 4,698,395).
A third commonly used method is grafting in molten state, e.g. in a single- or twin-screw extruder. This method has the disadvantages that the reaction time is limited and the reaction temperature is higher than in the above methods, and therefore the conversion usually remains rather low and the breaking up of polymer chains is considerable. The amount of free monomer can in part be reduced by means of vacuum suction or extraction methods, but these methods are usually ineffective and/or expensive.
German patent publication DE 2 023 145 discloses a method in which the grafting of a maleic acid anhydride onto a polymer can be enhanced by using as an aid one vinyl monomer. However, the method has the disadvantage that the amount of vinyl monomer required is high. The adhesion properties of the product are not reported.
European patent application EP 280 454 discloses a method in which, in addition to the functional monomer, a second monomer, for example styrene, is used in the grafting which copolymerizes under the effect of heat. The "grafting reaction" is performed in the absence of peroxide initiators which produce polymer radicals. The polyolefin used must not contain antioxidants.
Epoxy functionalization of ethylene-propylene rubber and ethylene-propylene-diene rubber is disclosed in patent application EP 274 744. According to it, the functionalization is performed with the aid of a peroxide initiator by using, for example, glycidyl acrylate as the functionalizing agent.
The present invention is characterized in that a polyolefin is grafted with a functional monomer and, in addition, two comonomers are used, of which one is an aliphatic (di)olefin and the other is an aromatic vinyl monomer or (meth)acrylate monomer.
The polymer to be functionalized is a polyolefin, such as a homo-, co- or terpolymer of ethylene, propylene, butene, or 4-methyl-pentene.
The functional monomer is an unsaturated carboxylic acid having a carbon-carbon double bond, a carboxylic acid anhydride, or some other carboxylic acid derivative such as carboxylic acid ester. Also an imide, either as such or imidized in situ from an anhydride, belongs to this group. Especially recommended are .alpha.-unsaturated carboxylic acids, corresponding anhydrides, and epoxy-, amino- and hydroxy functional (meth)acrylates. The amount of the functional monomer is 0.1-10% by weight, preferably 0.2-5% by weight, of the amount of the polymer.
In addition to the functional monomer the method of the invention uses so-called co-monomers, which can be divided into two categories: (1) aliphatic diolefins such as C.sub.6 -C.sub.18 .alpha.-olefins, preferably 1-octene, and (2) aromatic vinyl monomers and (meth)acrylates, preferably styrene or paramethyl styrene or buty acrylate. The combined total amount of the com
REFERENCES:
Abstract of DE 2,023,154 Nov. 1970.
Borealis Holding A/S
Zitomer Fred
LandOfFree
Method for functionalization of polyolefins does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for functionalization of polyolefins, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for functionalization of polyolefins will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-207113