Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Reexamination Certificate
2000-08-16
2002-03-12
Hampton-Hightower, P. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
C525S422000, C525S432000, C525S436000, C525S063000, C525S070000, C525S071000, C528S170000, C528S310000, C528S322000, C528S332000, C528S353000
Reexamination Certificate
active
06355737
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a novel process for producing polymer blends by reacting aminonitriles in the presence of water, thermoplastic polyamides and optionally further polyamide-forming monomers.
Plastics based on single polymers have disadvantages which limit their possible applications. By means of polymer blends it is possible to combine the different properties of the blending partners to improve the property profiles of plastics. This is why, for example, blends of polyamides and amorphous plastics such as polyarylene ether sulfones or polyetherimides are produced.
The polyamides can be produced in a very wide variety of ways. Among the most important methods for producing polyamides is the ring-opening hydrolytic polymerization of lactams. One version of this process, which can also be carried out in industry, is described in DE-A 43 21 683, for example.
2. Description of the Related Art
The production of polyamides from aminonitriles represents an alternative route and makes it possible to utilize other raw materials. For instance, DE-A 197 09 390, an earlier document which was unpublished at the priority date of the present invention, describes continuous and batch processes for producing polyamides from aminonitriles and water at elevated temperature and elevated pressure.
To produce polyamide blends, U.S. Pat. No. 3,729,527 proposes polymerizing &egr;-caprolactam, inter alia, in the presence of polyarylene ether sulfone. DE-A 41 02 996 likewise proposes polymerizing lactams in the presence of amorphous polymers such as polysulfones, polyphenylene ethers, polyetherimides, polyamideimides or styrene copolymers to produce polymer blends. The polymerization is initiated by means of strong bases. The polymerization is initiated by means of strong bases.
BRIEF SUMMARY OF THE INVENTION
If the polymeric blend components are mixed in the melt, for example in an extruder, it is customary to add compatibilizers to them. According to EP-A 0 374 988, McGrath et al., Polym. Prepr. 14, 1032 (1973) or Corning et al., Makromol. Chem. Macromol. Symp. 75, 159 (1993), useful compatibilizers include copolymers composed of polyamide and polyarylene ether sulfone segments, which are produced by dissolving the polyarylene ether sulfone in a lactam melt and polymerizing the lactam in the presence of a strong base and in the absence of water.
DETAILED DESCRIPTION OF THE INVENTION
Studies into the anionic polymerization of lactams in the presence of polyetherimides or polysulfones in an extruder have also been conducted for example by Van Buskirk et al., Polym. Prepr. 29(1), 557 (1988).
All the abovementioned processes utilize lactams or polyamides prepared from lactams for producing blends of polyamides and thermoplastic polymers.
The processes mentioned have the disadvantage that the polymer chains of the thermoplastic polymers are degraded by the attack of the anions present in the reaction mixture. In addition, the anionic polymerization requires special technical measures to control the degree of polymerization, since the reaction is generally very fast and the viscosity increases considerably within a short time. As a consequence, products having a defined structure, i.e., a defined chain length or viscosity, are difficult or impossible to obtain. In addition, the products contain catalyst residues and degradation or by-products which are frequently impossible to remove. If the polymerization is carried out in an extruder, it is frequently impossible to achieve complete conversion and the end product still contains residual monomers. Furthermore, in most cases, the only products obtained are dark, e.g., brown.
Schnablegger et al., Acta Polym. 46,307 (1995) describe the reaction of &egr;-caprolactam with polyarylene ether sulfones which contain aminophenyl end groups. The amino groups react with the &egr;-caprolactam by ring opening and thus initiate the polymerization reaction. The reaction is carried out in the absence of water, and phosphoric acid can be used as a catalyst. The disadvantage of this process is that polyarylene ether sulfones having two aminophenyl end groups per polymer chain are difficult to prepare pure.
It is an object of the present invention to provide an improved process for producing compositions based on different thermoplastic materials and polyamides (polymer blends) without the disadvantages of existing processes.
We have found that this object is achieved according to the invention by a preferably continuous process for producing a polyamide by reacting at least one aminonitrile with water in the presence of thermoplastic polymers and optionally further polyamide-forming monomers, which comprises the following steps:
(1) reacting at least one aminonitrile with water at a temperature from 90 to 400° C. and a pressure from 0.1 to 35×10
6
Pa, preferably in the presence of a Brönsted acid catalyst selected from a beta-zeolite catalyst, a sheet-silicate catalyst or a titanium dioxide catalyst comprising from 70 to 100% by weight of anatase and from 0 to 30% by weight of rutile and in which up to 40% by weight of the titanium dioxide may be replaced by tungsten oxide, to obtain a reaction mixture,
(2) further reacting the reaction mixture at a temperature from 150 to 400° C. and a pressure which is lower than the pressure in step 1, which can be carried out in the presence of a Brönsted acid catalyst selected from a beta-zeolite catalyst, a sheet-silicate catalyst or a titanium dioxide catalyst comprising from 70 to 100% by weight of anatase and from 0 to 30% by weight of rutile and in which up to 40% by weight of the titanium dioxide may be replaced by tungsten oxide, the temperature and pressure being selected so as to obtain a first gas phase and a first liquid or first solid phase or a mixture of first solid and first liquid phase and the first gas phase is separated from the first liquid or the first solid phase or the mixture of first liquid and first solid phase, and
(3) admixing the first liquid or the first solid phase or the mixture of first liquid and first solid phase with a liquid phase comprising water, which phase may contain the foregoing catalyst, at a temperature from 150 to 370° C. and a pressure from 0.1 to 30×10
6
Pa to obtain the polymer blend, wherein in one or more of the steps the thermoplastic polymers and optionally further polyamide-forming monomers are added.
The above process preferably additionally comprises the following step:
(4) postcondensing the polymer blend at a temperature from 200 to 350° C. and a pressure which is lower than the pressure of step 3, the temperature and pressure being selected so as to obtain a second, water- and ammonia-comprising gas phase and a second liquid or second solid phase or a mixture of second liquid and second solid phase, which each comprise the polymer blend.
The invention further provides a preferably continuous process for producing polymer blends by reacting at least one aminonitrile with water in the presence of thermoplastic polymers and optionally further polyamide-forming monomers, which comprises the following steps:
(1) reacting at least one aminonitrile with water at a temperature from 90 to 400° C. and a pressure from 0.1 to 35×10
6
Pa, preferably in the presence of a Brönsted acid catalyst selected from a beta-zeolite catalyst, a sheet-silicate catalyst or a titanium dioxide catalyst comprising from 70 to 100% by weight of anatase and from 0 to 30% by weight of rutile and in which up to 40% by weight of the titanium dioxide may be replaced by tungsten oxide, to obtain a reaction mixture,
(2) further reacting the reaction mixture at a temperature from 150 to 400° C. and a pressure which is lower than the pressure in step 1, which can be carried out in the presence of a Brönsted acid catalyst selected from a beta-zeolite catalyst, a sheet-silicate catalyst or a titanium dioxide catalyst comprising from 70 to 100% by weight of anatase and from 0 to 30% by weight of rutile and in which up to 40% by wei
Hildebrandt Volker
Mohrschladt Ralf
Weber Martin
BASF - Aktiengesellschaft
Hampton-Hightower P.
Keil & Weinkauf
LandOfFree
Method for producing polymer mixtures comprised of amino... 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 producing polymer mixtures comprised of amino..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for producing polymer mixtures comprised of amino... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2860846