US 4,943,399 AGrant
Continuous Preparation of Molding Materials Based on Polyphenylene Ethers and Nylons
Issue Date:1990-07-24
•4 Claims
Abstract
Thermoplastic molding materials based on polyphenylene ethers and nylons are prepared in an extruder by a continuous process in which a modified polyphenylene ether is prepared in a first zone of the extruder and is then mixed with nylons and, if required, further additives in one or more further zones.
Metadata
Assignee
- BASF Aktiengesellschaft
Inventors
- Christof Taubitz
- Hermann Gausepohl
- Erhard Seiler
- Klaus Boehlke
- Lothar Schlemmer
Application Information
Application Number:US 3499685
Filing Date:1989-05-08
Priority Date:1987-01-29
Art Unit:151
Classifications
IPC:
B29B 784C08L 7112C08L 7700
Field of Search:
264525211.12;211.18;211.21;211.23;211.24;101392;391;397
Patent Drawings
This patent does not have any drawings.
Description
EXAMPLES 1 TO 12
The process was carried out using a twin-screw extruder having three zones (Werner and Pfleiderer). The screw diameter was 53 mm and the lengths of the individual zones are stated as multiples of the screw diameter (D).
The first zone of the extruder was 15 D long and had a feed orifice for solid substances a.sub.1 to a.sub.3 at the beginning. These substances were fed in via metering balances. Below the feed orifice, the screw elements were designed for conveying, and this zone section (3 D) was cooled to 20.degree. C. The next zone section (3 D) was heated to 240.degree. C. The remainder of the first zone (9 D) was at 280.degree. C. In the middle section of the first zone, kneading elements were present on the screw. A backwardconveying element was incorporated at the end of the screw.
The second zone of the extruder was 15 D long and had a lateral feed orifice at the beginning. The remainder of the second zone was closed, except with respect to the devolatilization zone. The components B, D, E and F were fed through the lateral feed orifice into the second zone by means of a side extruder. The second zone was heated at 285.degree. C. The screw carried kneading elements.
The side extruder was a twin-screw extruder having a screw diameter of 30 mm and a length of 17 D. The extruder barrels of the side extruder were at 280.degree. C. At the beginning of the side extruder, the substances were fed in through metering balances, and at the end of the side extruder they were introduced into the lateral feed orifice of the second zone.
The devolatilization zone of the extruder was 6 D long and had, at the beginning, a devolatilization orifice at which a vacuum of 100 mmHg was applied. In the second section of the devolatilization zone, a pressure was built up in order to extrude the product via a die. The product was drawn through a water bath and then granulated and dried.
Specifically, the following components were used.
a.sub.1 : poly-(2,6-dimethyl-1,4-phenylene) ether (having a relative viscosity of 0.60, measured in 1% strength by weight CHCl.sub.3 solution at 25.degree. C.)
a.sub.2 /1: polystyrene PS 144 C from BASF, MFI 200/5.0=24 g/.sup.10 min
a.sub.2 /2: oligomeric polystyrene with M.sub.w =5,000 (corresponds to component D in Example 2)
a.sub.2 /3: copolymer of vinyltoluene and methylstyrene (M.sub.w =5,000; Picotex 120 from Hercules)
a.sub.3 /1: fumaric acid
a.sub.3 /2: maleic anhydride (MA)
a.sub.3 /3: diethyl maleate
a.sub.3 /4: mixture of 50% by weight of MA+50% by weight of methyl methacrylate
B/1: nylon 6,6 having a relative viscosity of 3.4
B/2: nylon 6 having a relative viscosity of 3.1
D: corresponds to component a.sub.2 /2
E/1: styrene/butadiene/styrene block polymer, prepared by anionic polymerization (32% by weight of styrene, 68% by weight of butadiene) and having an M.sub.w of 95,000
E/2: styrene/(hydrogenated) butadiene/styrene block rubber, prepared by anionic polymerization with subsequent hydrogenation of the polybutadiene block, containing 35% by weight of styrene and 65% by weight of (hydrogenated) butadiene, M.sub.w =65,000
E/3: ethylene polymer obtained from 70% by weight of ethylene, 29% by weight of n-butyl acrylate and 1% by weight of maleic anhydride and having an MFI of 20 g/10 min.
E/4: butadiene rubber, prepared by emulsion polymerization of, initially, 70% by weight of butadiene, followed by 30% by weight of styrene as a particle shell.
F/1: SiO.sub.2
F/2: polyethylene wax. Table 1 shows the amounts of components used.
Comparative Examples for Examples 3, 5 and 6
COMPARATIVE EXAMPLES 3.1, 5.1 AND 6.1
The components a.sub.1 -a.sub.3, B and D were all metered together into the first zone of the main extruder and mixed in the latter.
COMPARATIVE EXAMPLES 3.2, 5.2 AND 6.2
The components a1-a3 were metered into the first zone, fed via the main extruder, extruded and granulated. In a second pass, the components B and D with the granules were metered into the first zone, fed via the main extruder and mixed.
COMPARATIVE EXAMPLES 3.3, 5.3 AND 6.3
The components a.sub.1 and a.sub.3 (without components a.sub.2) were metered into the first zone, and B and D were metered into the second zone.
COMPARATIVE EXAMPLES 3.4, 5.4 AND 6.4
The components a.sub.1 and a.sub.3 were metered into the first zone and components a.sub.2, B and D into the second zone and mixed in the main extruder.
The results of the measurements of impact strength (according to DIN No. 53,453), notched impact strength (according to DIN No. 53,453) and total penetration energy (according to DIN No. 53,443) are shown in Table 2. The relevant test specimens were prepared by injection molding.
EXAMPLES 13 TO 16
In these Examples, a twin-screw extruder having four zones and a screw diameter of 53 mm was used. The first zone had a length of 20 D and its design corresponded to the first zone of the extruder in Examples 1 to 12. The second zone was 12 D long and was otherwise similar to the second zone of the extruder of Examples 1 to 12.
The third zone was 6 D long and had at the beginning a feed orifice above which was a dome flushed with N.sub.2 and open at the top. The substances E and F were fed in via metering balances, and glass fibers were drawn in via the screw of the main extruder.
The fourth zone (devolatilization zone) corresponded to that of the extruder in Examples 1 to 12.
Table 3 shows the proportions in which the individual components are mixed.
Components a.sub.1, a.sub.2, a.sub.3, B and E correspond to the components used in Examples 1 to 12.
The following were used in addition:
a.sub.4 : acrylic acid
F/3 talc
F/5 glass fibers
F/6 titanium dioxide
F/7 tris(nonylphenyl) phosphate
F/8 zinc oxide
F/9 zinc sulfide
F/10 kaolin
Comparative Examples for Example 15
COMPARATIVE EXAMPLE 15.1
Components a.sub.1 -a.sub.3, B, D and E were all metered together into the first zone and mixed in the main extruder, while component F was metered into the third zone.
COMPARATIVE EXAMPLE 15.2
Components a.sub.1 -a.sub.3 were metered into the first zone, fed via the main extruder, extruded and granulated. In a second pass, the components B, D and E with the granules of the mixture prepared from a1-a3 were metered into the first zone, and components F were metered into the third zone and mixed in the main extruder.
COMPARATIVE EXAMPLE 15.3
Components a.sub.1 and a.sub.2, without components a.sub.3, were metered into the first zone, B, D and E into the second zone and components F into the third zone.
COMPARATIVE EXAMPLE 15.4
Components a.sub.1 and a.sub.2 were metered into the first zone, components a.sub.3, B, D and E into the second zone and components F into the third zone.
The results of the measurements are shown in Table 4.
EXAMPLES 17 To 28
Examples 1 to 12 were repeated, except that 0.05% by weight of tert-butyl hydroperoxide was additionally used in the reaction in the first zone, the amount of PPE (A.sub.1) accordingly being reduced by 0.05% by weight. Otherwise, the compositions of Examples 17 to 28 correspond to those of Examples 1 to 12 (in this order, ie. 17=1, 18=2, . . . etc.).
After extrusion, granulation and drying, test specimens were prepared as in Examples 1 to 12 by injection molding, and the mechanical properties were determined.
The results of these measurements are shown in Table 5.
Claims
We claim
1. A continuous process for the preparation of a thermoplastic molding material based on polyphenylene ethers (PPE) and nylons in an extruder, wherein (I) in a first zone at from 240.degree. to 350.degree. C., (a.sub.1) from 50 to 99.95% by weight of a polyphenylene ether, (a.sub.2) from 0 to 45% by weight of a vinylaromatic polymer, (a.sub.3) from 0.05 to 10% by weight of one or more monomers selected from the group consisting of (a.sub.31) .alpha.,.beta.-unsaturated carboxylic acids or their derivatives of the general formula I ##STR12## wherein R.sub.1 and R.sub.4 are each hydroxyl, aryloxy, alkoxy, artalkoxy, cycloalkoxy, each of not more than 12 carbon atoms, together form --O-- or --NR.sub.5 --; R.sub.2 and R.sub.3 are each hydrogen, alkylo, cycloalkyl, each of not more than 12 carbon atoms, aryl, chlorine, or together form alkylene of 4 to 12 carbon atoms; the R.sup.5 is hydrogen, the moiety of alkyl, cycloalkyl, aralkyl, aryl, each moiety being not more than 12 carbon atoms, or the moiety is substituted by C.sub.1 -C.sub.4 -alkyl or -alkoxy, (a.sub.32) monomers containing amide groups and a polymerizable double bond and (a.sub.33) monomers containing lactam groups and a polymerizable double bond, (a.sub.4) from 0 to 80% by weight of further graft monomers and (a.sub.5) from 0 to 20% by weight of a free radical initiator, the percentages in each case being based on the total weight of components a.sub.1 to a.sub.5, are reacted for from 0.1 to 15 minutes, and a modified polyphenylene ether A is prepared, and (II) then, without cooling the modified polyphenylene ether, in one or more further zones of the extruder at from 250.degree. to 350.degree. C., (B) from 5 to 95% by weight of a nylon, (C) from 0 to 90% by weight of a nonmodified polyphenylene ether, (D) from 0 to 45% by weight of a vinylaromatic polymer, (E) from 0 to 40% by weight of a rubber impact modifier and (F) from 0 to 60% by weight of additives and processing assistants, the percentages being based on the total weight of components A-F, are added, and the resulting mixture is extruded.
2. The process as claimed in claim 1, wherein from 0.01 to 0.09% by weight of a free radical initiator a.sub.5 is used in the reaction in the first zone.
3. The process as claimed in claim 1, wherein the components E, F or a mixture thereof are added in a third zone, after the components B, C and D added in the second zone.
4. The process as claimed in claim 1, wherein the mixture of components A to F is devolatized in a further zone of the extruder.