SU519449A1 - Thermoplastic molding composition - Google Patents

Description

(54) THERMOPLASTIC FORMING COMPOSITION 5 The composition of compositions in all cases is given in weight, percent. Example. Powdered PMO stabilized by the above method was mixed with acetone dissolved in acetone with:, 1% of ED-6 in one case, and with high-boiling dissolved fractions of heavy petroleum hydrocarbons in the other. The ratio of POM and ZD-6 was 93: 7 and 80:20, and the ratio of POM and oil fractions (FN) was 98: 2 and 93: 7. The mixture was vigorously stirred until the solvent was completely evaporated and dried i to a constant weight. High-boiling oil fractions in an amount greater than 7%, not

The rheological properties of the melt, unplasticized and plasticized POM at 190 ° C and a shear stress of 4.0–10 dyn / cm are combined with the POM and simply melt from the melt during processing, making the process unstable. The effect of these additives on the properties of the POM melt was judged by the rheological characteristics (viscosity, flow regime). The flow pattern, which characterizes the degree of deviation from the laws of flow of a Newtonian fluid, was determined from the tangent of the tangent angle at a given point of the flow curve. The melting point was determined by differential thermal analysis. The results are presented in table. 1. J Table 1

The specified conditions for the determination of

with which the perforation of POM into fibers is carried out.

 / The plasticization effect was evaluated as the ratio of the melt viscosity of the non-plasticized polymer to the plasticized viscosity.

The data presented in Table. 1, n (it is noted that with the introduction of POM FN, a slight plasticizing effect is achieved (compared to epoxy resin), which, in fact, does not change with an increase in the FN content from 2 to 7%. Further j increase of F content H leads to the fact that the additive (as limited compatible) is squeezed out of the melt (during processing or in the process of measuring the viscosity), and therefore has no further plasticizing effect. Thus, with the introduction of the FN into the POM melt, the maximum effect viscosity is 20%. The melting point of POM is practically unchanged under the influence of FN (Table 1) - the changes are within the experimental error. With the introduction of ED-6., the melt capacity of the POM melts significantly (1.45 to 2 times), and current approaching Newton's. Both of these points are important in processing (especially

45 when spinning fiber). I

PRI mme R 2. According to the method indicated in Example 1, the compositions POM + + 5O% ED-6 and POM + 5O% FN were obtained.

60Frequently represented fat

(in the amount of 0.5-2%) coBVfecTfMbi with polyoxymethylene in the melt, therefore, it is impossible to achieve a large effect in the reduction in eco. Indeed, a mixture of POM + 5O% FN

85. at processing temperatures, it is not a single composition, but a two-phase system, from which an excess (non-intermixed) amount of FN flows during the processing or

60 viscosity measurements. The residual content of the characteristics is close to the conditions.

Ill In the mixture, the state “; lt is 5–7%, that C) gives a decrease in compression; and the melt is 1.2 times.

When content in the amount of 50% was observed, its full coBMecTHNrocTb

Rheogegic properties of the melt,

non-plasticized and plasticized POM l

at a temperature of 190 ° C and a shear stress of 4.0-10 dyne / cm) Plasticizing effect. POM 5-7% FN is shown, the remaining amount

 The addition of a 5O% epoxy resin provides a high plasticizing effect (Table 2), which makes it possible to process POM samples of increased melt viscosity. .The decrease in the melting temperature by 11 ° C makes it possible to process the PEM at: 6 lower temperatures, which provides an increased thermal stability of the dispersed POM.

Properties Volszhon without washing the plasticizer

Compositions containing more than 5% Fp are not processed into fibers, frequent breaks are observed due to inclusions of a non-coincident FN fraction.

From the data in Table 3, it can be seen that the polyoxchmethylene fiber containing plasticizers such as FN or β-bromonaphthalene is characterized by low physicomechanical indicators compared to fiber based on the composition G1OM + 1O%

with POLO in the melt,. inspection pia 10, what about: epoxy resins, from the point of view of construction, l. close to slightly polar representatives of the skin (of a wide range. The melt rheological properties of 5 compositions are presented in Table 2.

table 2

25P nmep 3. Composition POM + 1O%

ED-6, 1POM + 5 FN, POM + 10% oC naphthalene, and the original POM were processed into fibers on a conventional spin 20 (Machine of screw type. At a temperature of | l5O ° C and a draw rate of 50 m / min g | thermo-orientation stretching (fibers. The physicomechanical parameters of the fibers are given in Table 3.

Table 3

: ED-6, as well as in comparison with the volos from: the original POM. Thus, when plasticizing fractions of oil or other.i are used as plasticizers of low-molecular organic compounds (for example, bromonaphthalene) in the technological process, the 1st form process only leaks out of the melt.

Moving the fiber requires introducing a stage of washing the plasticizer from the fiber. After removal of plasticizers, the physicomechanical properties of the fiber are noticeably improved, however, both the strength and the maximum modulus remain lower than that of the fiber from the original POM. i

Introduction to POM of 10%, lowering the melt viscosity during formation, does not lead to a decrease in the physicomechanical properties of red tape, as a result of which the special stage of washing the plasticizer from the finished fiber disappears.

F o i) a mule of the invention

Thermoplastic molding composition, coci-o sha 03 polyoxymethylb, thermostat-dinan-diamide thermometer, aytioxidant1-2, 2-methylene-bis-X 4-methyl-6-t ret-6utylphenol) and an agent that causes a decrease in melt viscosity and polymer melt characterized in that, in order to improve the rheological properties of the composition, epoxy resins with a molecular weight of 20O-600 are used as an agent causing a decrease in the melt viscosity and melting temperature of the polymer, and the components of the composition are taken in a decreasing ratio, wt.%:

Epoxy resin5-50

Heat Stabilizer 0.25-1

Antioxidant 0.25-1

PolyoxymethyleneEmost

Sources of information taken into account in the examination:

1. Avt.Sv. USSR № 167950.1 1965, cl. C 08 G 37 / O2.