CN110066405B

CN110066405B - Master batch for direct spinning of polyester stock solution coloring melt and preparation method thereof

Info

Publication number: CN110066405B
Application number: CN201910417153.9A
Authority: CN
Inventors: 李志远
Original assignee: Changzhou Xinzhanjiang Special Fiber Co ltd
Current assignee: Jiangsu xinzhanjiang Fiber Technology Co.,Ltd.
Priority date: 2019-05-20
Filing date: 2019-05-20
Publication date: 2021-07-30
Anticipated expiration: 2039-05-20
Also published as: CN110066405A

Abstract

The invention belongs to the technical field of raw materials for melt direct spinning, and particularly relates to master batches for coloring a terylene stock solution and direct spinning and a preparation method thereof.

Description

Master batch for direct spinning of polyester stock solution coloring melt and preparation method thereof

Technical Field

The invention belongs to the technical field of raw materials for melt direct spinning, and particularly relates to master batches for coloring a polyester stock solution and a preparation method thereof.

Background

The melt direct spinning polyester fiber is gradually accepted by more and more terylene chemical fiber production enterprises due to low energy consumption, stable quality and obvious competitive advantage. Compared with chip spinning, the melt direct spinning has higher yield and larger extrusion capacity, but compared with chip spinning which utilizes a screw to realize forced mixing, the melt direct spinning adopts a mixing mode of online addition, so the mixing effect is weaker, and if the color master batch used by the chip spinning is directly used for the melt direct spinning, the color master batch has higher viscosity, so that frequent replacement of a prefilter and a filter core and too fast pressure rise are inevitably caused, and the production unit consumption is high, the high-quality product rate is low, flying filaments have more broken ends, the subsequent processing is difficult and the loss is high. Therefore, color master batches prepared from the resin with lower viscosity are needed for melt direct spinning.

But the problems are that: the viscosity of the resin of the color master batch is reduced in the preparation process, so that the molecular weight distribution of the resin of the color master batch is widened, the quality of the master batch fluctuates (the extrusion material is very fragile and is inconvenient to cut into granules), and the physicochemical properties and stability of a subsequent melt direct spinning product are further influenced, such as obvious defects, stripes, gross money and other problems on the product.

In contrast, many manufacturers select a resin with a higher viscosity (e.g., a high-viscosity bottle grade chip with an intrinsic viscosity of 0.8 to 0.85 or a PBT chip with an intrinsic viscosity of 1.0 to 1.05) to prepare color master batches, so as to compensate for the "viscosity drop" occurring at the later stage of the color master batch preparation process, but the high viscosity causes the deterioration of the fluidity of the resin at the earlier stage, and therefore, at the initial stage of screw processing of such a resin, a certain amount of dispersant needs to be added to improve the fluidity of the resin and the dispersibility of the pigment in the resin, which brings about the following problems: auxiliaries such as a dispersing agent and the like can be remained in the master batch all the time, so that more small molecular weight substances are separated out in the subsequent direct spinning process, the production is unstable, and the product quality is influenced.

Disclosure of Invention

In order to solve the technical problem, the invention provides a master batch for direct spinning of a polyester dope coloring melt, which comprises the following components in parts by weight

65-70 parts of resin

25-30 parts of colorant

0 to 5 parts of an auxiliary coloring agent,

wherein the resin is a big bright PET slice with the intrinsic viscosity of 0.62-0.65, compared with the currently selected raw materials in the industry, the intrinsic viscosity is obviously reduced,

the colorant is carbon black, and the colorant is carbon black,

the auxiliary colorant is one or a combination of more of phthalocyanine pigment, azo condensed pigment, ultramarine inorganic pigment, anthraquinone violet oil-soluble dye, aminoketone red oil-soluble dye and perylene green oil-soluble dye.

The invention also provides a preparation method of the master batch for the direct spinning of the coloring melt of the terylene stock solution, which comprises the following specific operations:

freezing and grinding resin, mixing the ground resin and a coloring agent, firstly adopting high-speed blending during mixing, converting the mixture into low-speed blending when the temperature of the mixture is raised to 110 ℃ by utilizing self-friction heat generation of the material in the high-speed blending process, blending at low speed until the water content in the mixture is lower than 30ppm, then putting the mixture into a double-screw extruder for extrusion and granulation to obtain master batches,

extruding and granulating by a high-torque strong-shearing combined double-screw extruder with double forced exhaust, wherein the length-diameter ratio of the double-screw extruder is 48: 1; the temperature of the extrusion section is controlled to be 220-255 ℃; the extruder barrel was equipped with dual forced vents.

In the scheme, the key problem of viscosity reduction caused by hydrolysis in the preparation process is solved, the resin is frozen and ground into powder, and the mixture of the resin and the carbon black is subjected to a stirring process of high-speed mixing → low-speed mixing (the high-speed mixing not only fully mixes the materials, but also utilizes self-friction heat generation between the materials to increase the material temperature, the material temperature is converted into low-speed mixing after being increased to a certain degree, the low-speed mixing equipment plays a role similar to a boiling bed at the moment, water vapor converted from the water inside the materials by heating in the turning and stirring process of the materials is fully released), so that the water content in the raw material resin base material, the carbon black and the auxiliary coloring agent is strictly controlled, the viscosity reduction in the master batch preparation process is greatly inhibited, the viscosity reduction is inhibited, a large amount of dispersing agent does not need to be used and added in a matching manner, the phenomenon of excessive precipitation of small molecular weight substances in the direct spinning process caused by a dispersing agent is avoided, and meanwhile, the raw material cost is also reduced;

it is worth mentioning that the colorant used in the present scheme is carbon black, which is very easy to absorb moisture in air during storage, and thus can bring moisture into the extrusion granulation process. The carbon black is made of carbon materials and is easy to heat, so that the carbon black is very easy to ignite and even detonate when the carbon black is subjected to thermal drying, and the phenomenon that the viscosity is reduced when the carbon black without water is used as a coloring agent to prepare master batches is caused because the carbon black or a mixture with high carbon black content is basically not subjected to heating and temperature rise in the air environment in the prior art. The applicant has found that when the carbon black powder is mixed with the resin in the scheme, the temperature is raised and water is removed, and no carbon black combustion phenomenon occurs, which is not expected by the skilled person.

Drawings

FIG. 1 is a schematic structural diagram of an apparatus used in the process of "high-speed mixing → low-speed mixing → extrusion granulation" of raw materials in the present invention,

wherein, 1-high speed mixing equipment, 2-low speed mixing equipment, 3-double screw extruder, 4-material conveying pipe, 5-exhaust pipe, 51-wet towel,

when the high-speed mixing device 1 and the low-speed mixing device 2 carry out mixing and stirring operation, the materials occupy 1/3 dissolved in the stirring cavity of the mixing device,

the discharge ports of the high-speed mixing device 1 and the low-speed mixing device 2 are both positioned at the positions close to the bottom of the side surfaces of the devices and are communicated with the material conveying pipe 4, and the top parts of the high-speed mixing device 1 and the low-speed mixing device 2 are both provided with vertical exhaust pipes 5 communicated with the stirring cavity of the devices (under the condition that the discharge ports of the mixing devices are closed, except that the exhaust pipes 5 are communicated with the outside, the stirring cavity of the mixing devices is in a sealed state, so that carbon black is prevented from floating outwards in the stirring process), and water vapor formed by converting water in the mixture is discharged out of the mixing devices; meanwhile, the air outlets at the tops of the exhaust pipes 5 are covered with wet towels 51 or filter screens, because carbon black is light, the phenomena of obvious dispersion and floating fog can be generated under the stirring action, and the covering of the wet towels 51 or the filter screens can prevent the carbon black from rushing out of the mixing equipment through the exhaust pipes 5 as far as possible on the premise of ensuring the water vapor to pass through.

Detailed Description

Example 1

Crushing 70 parts by weight of bright PET chips (general Plastic products Co., Ltd., Guangzhou city) with the intrinsic viscosity of 0.65 to 30 meshes at a low temperature of 15 ℃, adding 25 parts by weight of nano-scale carbon black (with the particle size of 25nm) into the crushed resin powder after the temperature of the crushed resin powder naturally returns to a normal temperature (25 ℃, the same below), adding the obtained mixture into a high-speed mixing device 1, starting mixing and stirring at the stirring speed of 400 revolutions per minute, continuously stirring for 10 minutes at the speed to increase the material temperature of the mixture to 110 ℃, opening a discharge port on the high-speed mixing device 1, pumping the mixture into a low-speed mixing device 2 through a delivery pipe 4 by using the centrifugal force during stirring in the high-speed mixing device 1, stirring at the low speed of 20 revolutions per minute, stirring at the speed for 50 minutes, and reducing the water content in the mixture to 30ppm, at this moment, a discharge port on the low-speed mixing equipment 2 is opened, the mixture is squeezed into the high-torque strong-shearing combined double-screw extruder 3 with the double-forced exhaust port through the conveying pipe 4 by utilizing the centrifugal force during stirring in the low-speed mixing equipment 2 to extrude and granulate (the granulating process is stable, the master batch size is uniform), and the length-diameter ratio of the double-screw extruder 3 is 48: 1; the temperature of the extrusion zone was set to 220 ℃ in the first zone, 240 ℃ in the second zone, 255 ℃ in the third zone, 240 ℃ in the fourth zone, 240 ℃ in the fifth zone, 230 ℃ in the sixth zone, 230 ℃ in the seventh zone, 225 ℃ in the eighth zone, 225 ℃ in the ninth zone, 225 ℃ in the tenth zone, 225 ℃ in the eleventh zone, and 220 ℃ in the twelfth zone in this order.

The intrinsic viscosity of the master batch obtained by extrusion granulation was 0.45.

Example 2

Crushing 70 parts by weight of bright PET chips (Qiyuan plastic raw material Co., Ltd., Dongguan city) with the intrinsic viscosity of 0.65 to 30 meshes at the low temperature of 10 ℃, naturally recovering the temperature of the crushed resin powder to normal temperature, adding 30 parts by weight of nano-scale carbon black (the particle size is 25nm) into the resin powder, adding the obtained mixture into a high-speed mixing device, starting mixing and stirring at the stirring speed of 400 revolutions per minute, continuously stirring at the stirring speed for 10 minutes to increase the material temperature of the mixture to 114 ℃, opening a discharge port on the high-speed mixing device, pumping the mixture into a low-speed mixing device through a delivery pipe by using the centrifugal force during stirring in the high-speed mixing device, wherein the stirring speed during low-speed mixing is 18 revolutions per minute, stirring at the stirring speed for 46 minutes to reduce the water content in the mixture to 30ppm, opening the discharge port on the low-speed mixing device, centrifugal force when utilizing stirring among the low-speed mixing apparatus squeezes the mixture into the high moment of torsion of taking two compulsory gas vents through the conveying pipeline and cuts combination twin-screw extruder extrusion granulation by force (cut grain process stability, the master batch size is even), and twin-screw extruder's draw-ratio is 48: 1; the extrusion temperature was controlled as in example 1.

The intrinsic viscosity of the master batch obtained by extrusion granulation was 0.42.

Comparative example 1

70 parts by weight of large bright PET (polyethylene terephthalate) slices (general plastic products, Inc. of Guangzhou city) with the intrinsic viscosity of 0.65 are crushed to 30 meshes at the low temperature of 15 ℃, after the temperature of the crushed resin powder is naturally restored to the normal temperature (25 ℃, the same below), 25 parts by weight of nano carbon black (the particle size is 25nm) is added into the large bright PET slices, the obtained mixture is mixed and stirred in a high-speed mixing device 1 at the rotating speed of 400 rpm for 1.5 minutes to be fully mixed, the obtained mixture enters a high-torque strong-shearing combined double-screw extruder 3 with double forced air vents to be extruded and granulated (when granules are cut unevenly, due to the fact that the brittleness of an extruded material is large, the extruded material flow is frequently broken at a non-cutting part under the stress action, and large and small master batches are caused), and the length-diameter ratio of the double-screw extruder 3 is 48: 1; the extrusion temperature was controlled as in example 1.

The intrinsic viscosity of the master batch obtained by extrusion granulation was 0.24.

Claims

1. A preparation method of master batch for direct spinning of polyester dope coloring melt is characterized by comprising the following steps: the master batch comprises the following components in parts by weight

65-70 parts of resin

25-30 parts of colorant

0 to 5 parts of an auxiliary coloring agent,

the resin is a big bright PET slice with the intrinsic viscosity of 0.62-0.65,

the colorant is carbon black;

the preparation method comprises the following steps of,

freezing and grinding resin, mixing the ground resin and a coloring agent, performing high-speed blending during mixing, raising the temperature of the material by utilizing self-friction heat generation of the material in the high-speed blending process, heating to a certain degree, then converting into low-speed blending, performing low-speed blending until the water content of the mixture is lower than 30ppm, and then putting the mixture into a double-screw extruder for extrusion and granulation to obtain master batches.

2. The method for preparing the master batch for the direct spinning of the colored melt of the terylene stock solution according to claim 1, which is characterized in that: extruding and granulating by a high-torque strong-shearing combined double-screw extruder with double forced exhaust, wherein the length-diameter ratio of the double-screw extruder is 48: 1; the extrusion temperature is controlled to be 220-255 ℃; the extruder barrel was equipped with dual forced vents.

3. The method for preparing the master batch for the direct spinning of the colored melt of the terylene stock solution according to claim 1, which is characterized in that: the stirring speed during high-speed blending is 350-400 r/min.

4. The method for preparing the master batch for the direct spinning of the colored melt of the terylene stock solution according to claim 1, which is characterized in that: the stirring speed in the low-speed blending is 15-20 revolutions per minute.