RU2048487C1 - Process for preparing filled polymeric composition - Google Patents

Abstract

FIELD: manufacture of cable plasticate, tubes, building sheet materials. SUBSTANCE: suspension polyvinyl chloride is introduced in combination with a stabilizer suspension in a plasticizer (15-25 wt of the total charge) into a mixer at 20 to 60 C. The whole is stirred and, as soon as the temperature reaches 70 to 75 C, the remaining stabilizer suspension with a filler is added and the stirring is thereafter continued till the temperature reaches 80 to 120 C. EFFECT: more efficient preparation process. 1 tbl

Description

 The invention relates to the field of manufacturing compositions based on plasticized polyvinyl chloride (PVC) and can be used primarily for producing PVC-filled compositions, which are used in the manufacture of cable plastic compound, as well as in the production of pipes, sheet building materials, etc.

A method of producing PVC composition [1] in which the upper chamber is introduced a high-speed mixer under stirring components and stirred 15-20 minutes at 90-100 ^{° C,} is transferred into the lower chamber, and stirred for another 10-15 min to cool to ^about 35-40 C. A composition comprising 100 parts by weight PVC 50-120 wt. h of plasticizer (dialkyl phthalate (DAF ₇₈₉ ), tetraoctyl pyromellitate (TOPM), chloroparaffin (KP-300), 50-150 parts by weight of filler (chalk t / d, kaolin KD-10, Al (OH) ₃ ), 1-5 parts stabilizer (lead tribasic sulfate (TOSS Verpackungssysteme), dibasic lead phthalate (DOFTS), calcium stearate (CTCA) obtained by this process has a weight loss of 3.1-4.8% estimated lifetime at 70 ° ^C 5.5-17.1 years, extrusion capacity 230-300 g / min.

Another known method of producing vysokoplastifitsirovannoy compositions based on homo- and copolymers of vinyl chloride (VC) [2], comprising mixing a homo- or copolymer BX dry ingredients, the introduction of the first portion of the plasticizer with agitation, raising the temperature of the mixture to 80-85 ^{° C,} the introduction of the remainder of the plasticizer with stirring and cooling the mixture, followed by processing with a powdery filler, in which the first part of the plasticizer is introduced in an amount of 70-72% of the total weight of the plasticizer and the second part of the plasticizer DYT mixture at a stirring speed of 950-1000 r / min. A composition containing 100 parts by weight of PVC 50-120 parts by weight plasticizer (DAF ₇₈₉ , TOPM, HP-300), 50-150 parts by weight filler (chalk t / d, kaolin KD-10, Al (OH) ₃ ), 1-5 parts by weight stabilizer (TOSS Verpackungssysteme, DOFTS, CTCA) obtained by this process has a weight loss of 2,4-4,0% estimated lifetime at 70 ° ^C 7,1-17,5 years, extrusion productivity 250-310 g / m .

The closest in technical essence and attainable result to the proposed method for producing a filled polymer composition of [3], comprising mixing of PVC with the filler in a mixer, heated to 80-100 ^{° C} for 8-10 min, administering for 8-10 min pre heated to ⁷⁰ ° C a suspension stabilizer in the plasticizer, and stirring the mixture at a temperature of 100-120 ^{° C} for 10-30 min. A composition containing 100 wt. including PVC 50-120 parts by weight plasticizer (DAF ₇₈₉ , TOPM, HP-300), 50-150 wt. including filler (chalk t / d, kaolin KD-10, Al (OH) ₃ ), 1-5 parts by weight stabilizer (TOSS Verpackungssysteme, DOFTS, CTCA) obtained by this process has a weight loss of 2.0-3.5% estimated lifetime at 70 ° ^C 8,6-18 s, extrusion productivity 280-350 g / min.

 The aim of the invention is to reduce losses in mass, increase the service life of the composition and the performance of its extrusion.

The goal is achieved in that a method for producing filled polymer composition comprising mixing the slurry with polyvinyl chloride suspension stabilizer and filler in the plasticizer in a mixer with heating to 80-120 ^{° C,} part of the slurry stabilizer in an amount of 15-25 wt. of the total feed introduced into the mixer together with the polyvinyl chloride at a temperature of 20-60 ^{° C,} and the balance of its amount, together with a filler at 70-75 ° ^C.

In the proposed method, use: PVC suspension grades PVC-S-7058M, PVC-S-7059M (GOST 14332-78); plasticizers DAF ₇₈₉ (GOST 8728-77 with amendment No. 1), TOPM (TU 6-05-111-1-256-80), chloroplast ХП-300 (TU 6-01-13-1884-88); TOSS stabilizers (TU 6-09-4098-75 with amendment 1-5), DOPTS (TU 6-09-600-76), StSa (TU 6-14-732-76), chalk fillers. t / d (TU 6-18-38-81 as amended by N 3) (, kaolin KD-10 (TU 21-25-243-85), Al (OH) ₃ (TU 6-47-107-88) ; equipment high-speed mixer "Papenmeier" (volume of hot mixer V _g = 30 l, rotation speed of the mixer of the hot mixer n _g = 600-2000 rpm), "Gruzioma" (V _g = 780 l, n _g = 450-900 r / min), Henschel (v _g = 10 l, n _g = 800-1500 rpm), Buss extruder (mixing screw with a diameter of 46.5 mm and a ratio of length to diameter 6, extruding screw with a diameter of 41 mm and the ratio of length to diameter 4).

0,3(1) [1] (ε_t относительное удлинение в момент времени t, ε_иcх исходное значение относительного удлинения), что соответствует пределу допустимого изменения эксплуатационных свойств реальных пластифицированных материалов из ПВХ. Для экспериментальной температуры старения зависимость коэффициента старенияK_ε аппроксимируется прямолинейной зависимостью типа:
K_ε 1-С τ (2), где С постоянная, физический смысл которой скорость изменения коэффициента старения;
τ время старения.PRI me R s 1-10. In the mixer at a mixing temperature of 20-60 ^about With enter 100 wt. h. brand PVC PVC S-70, and pre-prepared suspension stabilizer in the plasticizer (the first part in an amount of 15-25% of the total weight of the suspension), the mixing temperature is raised to 70-75 ^{° C} and 15-600 was administered with a filler and a second portion suspension, then the mixture is stirred to 80-120 ^about C, after which the mixture is transferred to a cooler, where it is cooled to 30-40 ^about C. The cooled mixture is granulated at a melt temperature of 150-170 ^about C. Samples for testing are prepared by a roll-press method. Determine the loss in weight at 160 ^{° C} for 6 hours in accordance with the GOST 5960-72, extruding performance as the weight (in grams) of the melt emerging from the extruder head for 1 minute at constant mixer screw rotation speeds and pelletizer. Expected lifetime at 70 ° ^C is determined by an accelerated aging procedure, developed at SRI polymers. The essence of the accelerated method used to assess the estimated service life of plasticized PVC is that at elevated temperatures determine the time (τ _t ) during which the relative elongation of the material reaches a critical value. The critical value is K

0.3 (1) [1] (ε _t elongation at time t, ε _xt initial value of elongation), which corresponds to the limit of permissible changes in the operational properties of real plasticized PVC materials. For the experimental aging temperature, the dependence of the aging coefficient K _{ε is} approximated by a linear dependence of the type:
K _ε 1-C τ (2), where C is a constant, the physical meaning of which is the rate of change of the aging coefficient;
τ aging time.

(3)
Для расчета срока службы композиции при температуре эксплуатации применена следующая зависимость:
lgτ_э= lgτ_т+

(4) где Т_э, Т температуры эксплуатации и ускоренного старения соответственно,
Е коэффициент температурной зависимости процесса изменения показателя "относительное удлинение при разрыве ".The time to reach the critical value of K _ε is determined by the formula
τ _t =

(3)
To calculate the service life of the composition at operating temperature, the following dependence was applied:
lgτ _e = lgτ _t +

(4) where T _e , T operating temperatures and accelerated aging, respectively,
E is the coefficient of temperature dependence of the process of changing the indicator "elongation at break".

 The method parameters, composition and properties of the obtained compositions are shown in the table.

Claims (1)

METHOD FOR PRODUCING A COMPLETED POLYMER COMPOSITION, comprising mixing suspension polyvinyl chloride with a suspension of a stabilizer in a plasticizer and a mineral filler in a mixer when heated to 80-120 ^° C, characterized in that, in order to reduce mass loss, increase the service life of the composition and its extrusion performance, part suspension of the stabilizer in an amount of 15 25% by weight of the total load is introduced into the mixer simultaneously with polyvinyl chloride at 20 60 ^o C, and the rest of its amount together with the filler at 70 75 ^o C.

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