Multilayer composite polypropylene color master batch and preparation method thereof

Abstract

The invention discloses a multi-layer composite polypropylene color master batch and a preparation method thereof.The multi-layer composite polypropylene color master batch comprises an inner layer, a middle layer and an outer layer, the inner layer is coated with the middle layer, the middle layer is coated with the outer layer, matrix resin, a composite toughening agent and an interface modifier are subjected to melt blending in a double-screw extruder, nano reinforcing filler is added, extrusion granulation is performed, and the multi-layer composite polypropylene color master batch is obtained. Carrier resin, hyperbranched polyesteramide and a toner pre-dispersion body are mixed at a high speed and then uniformly coated on the outer surface of the inner layer through fluidized bed equipment, and a mixture of a weather-proof additive and a lubricant is attached to the outer surface of the middle layer by adopting an electrostatic spraying process to form the outer layer. According to the multi-layer composite color master batch, the matrix resin and the composite toughening agent have a synergistic effect, so that the impact strength of the color master batch is improved, the cavity structure of hyperbranched polyesteramide is coated with the toner, the silane is used for treating the nano filler to reduce agglomeration and chromatic aberration, the outer layer delays aging, the lubricant reduces the extrusion torque, and the multi-layer composite color master batch is adaptive to a high-speed pipe production line.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer material modification, and more particularly to a multilayer composite polypropylene color master batch and a preparation method thereof. BACKGROUND

[0002] Polypropylene pipes are widely used due to their corrosion resistance, light weight and other advantages, but their low-temperature brittleness and poor impact resistance limit their application in harsh environments. In the prior art, color master batches are mainly composed of a single toughening agent (such as POE or EPDM) or a filler (nano calcium carbonate), which has problems such as uneven dispersion, low toughening efficiency, and insufficient low-temperature performance. For example:

[0003] Patent CN119022137A adopts a three-layer structure design, but the middle layer only relies on EPDM and nano CaCO3, and the interface compatibility problem is not solved;

[0004] Patent CN102850658A is toughened by SBS / EVA composite, but does not combine with crystal type regulation technology, and the low-temperature toughness is limited;

[0005] Therefore, a technical solution is needed to solve the above problems. SUMMARY

[0006] The present application aims to overcome the shortcomings of the prior art, and uses a three-layer composite color master batch to improve the low-temperature impact toughness of the pipe, and provides a multilayer composite polypropylene color master batch and a preparation method thereof.

[0007] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0008] The present application discloses a multilayer composite polypropylene color master batch, which comprises an inner layer, a middle layer and an outer layer. The middle layer is coated on the outside of the inner layer, and the outer layer is coated on the outside of the middle layer. The weight percentage of the inner layer is 50-60%, the weight percentage of the middle layer is 20-30%, and the weight percentage of the outer layer is 10-20%.

[0009] Further, the inner layer comprises:

[0010] Base resin: 50-70 parts of beta crystal polypropylene;

[0011] Composite toughening agent: 10-20 parts of hydrogenated styrene-isobutene-styrene, 5-15 parts of ethylene-octene copolymer, and 5-10 parts of ternary ethylene-propylene rubber;

[0012] Nano reinforcing filler: 5-10 parts of nano calcium carbonate treated with silane coupling agent and 3-8 parts of nano barium sulfate;

[0013] Interface modifier: 3-5 parts of maleic anhydride grafted polypropylene.

[0014] Further, the intermediate layer comprises:

[0015] Carrier resin: alpha crystalline polypropylene 70-80 parts;

[0016] Dispersion system: hyperbranched polyester amide, hyperbranched polyester amide includes disulfide bond 5-10 parts, polyethylene wax 2-5 parts;

[0017] Color powder pre-dispersion 10-15 parts.

[0018] Further, the outer layer comprises:

[0019] Weathering aid: antioxidant 1010 1-2 parts, ultraviolet absorber UV-531 0.5-1 part;

[0020] Lubricant: calcium stearate 1-3 parts.

[0021] The application also discloses a preparation method for preparing the multilayer composite color master batch.

[0022] S1, preparation of the inner layer: melt blending the base resin, the composite toughening agent and the interface modifier in a double screw extruder, adding nano reinforcing filler, and extruding and granulating;

[0023] S2, preparation of the intermediate layer: after high-speed mixing the carrier resin, the hyperbranched polyester amide and the color powder pre-dispersion, uniformly coating the intermediate layer on the outer surface of the inner layer through a fluidized bed device;

[0024] S3, preparation of the outer layer: using electrostatic spraying process to adhere the mixture of the weathering aid and the lubricant to the outer surface of the intermediate layer to form the outer layer.

[0025] Further, the fluidized bed device comprises a first fluidized bed, a first fan, a heat source and an exhaust pipe, the first fluidized bed comprises a first partition plate, an air inlet and an air outlet, the first partition plate divides the first fluidized bed into a first cavity and a second cavity, the first cavity is used for feeding the intermediate layer material, the second cavity is used for feeding the inner layer material, the second cavity is located above the first cavity, the aperture of the first partition plate is greater than the particle size of the intermediate layer material and smaller than the particle size of the inner layer material, the air inlet is directed to the bottom of the first cavity, the first fan is connected with the heat source, the heat source is connected with the air inlet, the air outlet is located at the top of the first fluidized bed, and the air outlet is connected with the exhaust pipe.

[0026] Further, the fluidized bed device comprises a cooling tower and a second fan, the first fluidized bed is provided with a discharge port connected to the cooling tower, the second fan is connected to the cooling tower, and the first partition plate is arranged obliquely, and the discharge port is located at the lower side of the first partition plate.

[0027] Further, the fluidized bed device comprises a second fluidized bed which has the same structure as the first fluidized bed, a first valve is arranged between the first fluidized bed and the exhaust pipe, a second valve is arranged between the second fluidized bed and the exhaust pipe, and the first fluidized bed and the second fluidized bed are switched to operate.

[0028] Further, the first fluidized bed comprises a second partition plate located in the second cavity, the second partition plate is close to the air outlet, and the gap of the second partition plate is smaller than the particle size of the intermediate layer material.

[0029] Further, the first fluidized bed comprises a stirring rod penetrating through the second partition plate, the stirring rod extends downward, the stirring rod is provided with a plurality of paddles arranged along the length direction of the stirring rod, the paddles extend radially towards the stirring rod, the length of the paddles gradually decreases from top to bottom, and the stirring rod is provided with a scraper, and the upper edge of the scraper contacts the lower end surface of the second partition plate.

[0030] The beneficial effects of the present application are:

[0031] 1. The synergistic effect of the base resin β-PPR and the SIBS / POE / EPDM composite toughening system, the β crystal nucleating agent induces the formation of spherulite structure, the impact strength at -20℃ is improved by 50% compared with the traditional color masterbatch, and the low temperature toughness of the prepared pipe fitting is improved.

[0032] 2. The cavity structure of the hyperbranched polyester amide coats the toner, the silane treated nano filler reduces agglomeration, reduces color difference (ΔE≤1.5), and optimizes dispersion stability.

[0033] 3. The outer layer of the color masterbatch forms an antioxidant protective layer to delay aging, and the lubricant reduces the extrusion torque by 10%-15%, which is suitable for high-speed pipe production line.

[0034] 4. The intermediate layer is coated on the outer surface of the inner layer by using the fluidized bed technology, the intermediate layer material is collided through the inner layer material by using hot air, the stirring rod is added at the upper end of the particle tumbling, the collision between the materials is more sufficient and uniform, the intermediate layer particles and the inner layer particles of different weights can be stably collided, coated and mixed, the coating effect of the ordinary stirring and heating mixing is better, the double fluidized bed switching operation mode can produce without stopping, and the production efficiency is higher. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 A sectional view of the color master batch in the embodiment.

[0036] Figure 2 A schematic view of the fluidized bed equipment in the embodiment.

[0037] Figure 3 A schematic view of the first fluidized bed and the second fluidized bed in the embodiment.

[0038] Fig. 1 is a sectional view of the color master batch in the embodiment. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments will be described clearly and completely below in conjunction with the drawings in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0040] As shown in Figure 1 The present embodiment discloses a multi-layer composite polypropylene color master batch. The color master batch adopts a three-layer coating structure and comprises, from inside to outside, an inner layer 1, an intermediate layer 2, and an outer layer 3. The inner layer 1 is a toughening core layer, the intermediate layer 2 is a dispersion transition layer, and the outer layer 3 is a functional layer. The weight ratio of the inner layer 1 is 50%-60%. The inner layer 1 comprises:

[0041] Base resin: 50-70 parts of β-crystal polypropylene (β-PPR modified by β nucleating agent);

[0042] Composite toughening agent: 10-20 parts of hydrogenated styrene-isobutylene-styrene (SIBS), 5-15 parts of ethylene-octene copolymer (POE), and 5-10 parts of ethylene-propylene-diene rubber (EPDM);

[0043] Nano-reinforced filler: 5-10 parts of nano calcium carbonate (particle size 50-100 nm) treated by silane coupling agent and 3-8 parts of nano barium sulfate;

[0044] Interface modifier: 3-5 parts of maleic anhydride grafted polypropylene (PP-g-MAH).

[0045] The intermediate layer 2 is coated on the outside of the inner layer 1, and the weight ratio of the intermediate layer 2 is 20%-30%, and the intermediate layer 2 comprises:

[0046] Carrier resin: alpha crystalline polypropylene (a-PPR) 70-80 parts;

[0047] Dispersion system: hyperbranched polyester amide (containing disulfide bond 5-10 parts, polyethylene wax 2-5 parts);

[0048] Color powder pre-dispersion: silane treated phthalocyanine blue / titanium dioxide 10-15 parts.

[0049] The outer layer 3 is coated on the outside of the intermediate layer 2, and the weight ratio of the outer layer 3 is 10%-20%, and the outer layer 3 comprises:

[0050] Weathering aid: antioxidant 1010 1-2 parts, ultraviolet absorber UV-531 0.5-1 part;

[0051] Lubricant: calcium stearate 1-3 parts.

[0052] The color master batch of the embodiment uses the synergistic effect of beta-PPR and SIBS / POE / EPDM composite toughening system, beta crystalline nucleating agent induces the formation of spherulite structure, the impact strength at-20℃ is increased by 50% compared with traditional color master batch, the cavity structure of hyperbranched polyester amide covers the color powder, the silane treated nano filler reduces agglomeration, the color difference ΔE is less than or equal to 1.5, the outer antioxidant / UV protective layer delays aging, the lubricant reduces the extrusion torque by 10%-15%, and it is suitable for high-speed pipe production line.

[0053] The report of the National Chemical Building Material Quality Inspection and Testing Center shows that:

[0054]

[0055] As shown in the above table, the pipe made of PPR raw material added with the color master batch of the embodiment has obvious improvement in impact resistance in normal temperature or low temperature environment.

[0056] As shown in Figure 2 , Figure 3 The embodiment also discloses a preparation method for preparing the above-mentioned multilayer composite color master batch, which comprises the following steps:

[0057] S1, preparation of the inner layer 1: melt blend the base resin beta-PPR, the composite toughening agent (SIBS / POE / EPDM) and the interface modifier PP-g-MAH in a twin-screw extruder (temperature 190-210℃), add nano reinforcing filler, and extrude and granulate;

[0058] S2, preparation of the intermediate layer 2: the carrier resin α-PPR, hyperbranched polyester amide and toner pre-dispersion are uniformly coated on the outer surface of the inner layer 1 by high-speed mixing (2000 rpm, 10 min) and the coating technology of the fluidized bed equipment;

[0059] The fluidized bed equipment comprises a first fluidized bed 41, a second fluidized bed 42, a first fan, a heat source, and an exhaust pipe 5. The first fluidized bed 41 and the second fluidized bed 42 have the same structure. The first fluidized bed 41 comprises a first partition plate 411, an air inlet 414, a first feeding port 415, a second feeding port 416, and an air outlet 419. The first partition plate 411 divides the first fluidized bed 41 into a first cavity 412 and a second cavity 413. The first cavity 412 is used for feeding the intermediate layer 2 material, and the second cavity 413 is used for feeding the inner layer material 102. The second cavity 413 is located above the first cavity 412. The aperture of the first partition plate 411 is larger than the particle size of the intermediate layer 2 material and smaller than the particle size of the inner layer material 102. The first feeding port 415 is connected to the first cavity 412, and the first feeding port 415 feeds the intermediate layer material 101 into the first cavity 412. The second feeding port 416 is connected to the second cavity 413, and the second feeding port 416 feeds the inner layer material 102 into the second cavity 413. The air inlet 414 is directed towards the bottom of the first cavity 412. The first fan is connected to the heat source, and the heat source is connected to the air inlet 414. Hot air is blown into the first cavity 412 from the air inlet 414. The lower end of the first cavity 412 is in the shape of a conical taper. The air inlet 414 is aligned with the center of the bottom of the first cavity 412, so that the hot air can blow the intermediate layer material 101 upwards from the bottom. The hot air heats and blows the intermediate layer material 101 upwards. The intermediate layer material 101 can pass through the first partition plate 411, and the inner layer material 102 on the first partition plate 411 is also blown up. Since the particle weight of the intermediate layer material 101 is smaller than that of the inner layer material 102, the intermediate layer material 101 can pass through the inner layer material 102. The intermediate layer material 101 collides with the upper half of the inner layer material 102. The hot air and the particles collide with each other, causing the intermediate layer material 101 to melt and coat the outer wall of the inner layer material 102. The particle weight of the inner layer material 102 after coating the intermediate layer material 101 increases. The coated particles are located at the lower end of the second cavity 413. The inner layer material 102 without the intermediate layer material 101 rises and collides with the intermediate layer material 101 for coating. The air outlet 419 is located at the top of the first fluidized bed 41. The air outlet 419 is connected to the exhaust pipe 5, and the air outlet 419 guides the internal hot air outward and exhausts it.

[0060] The first fluidized bed 41 comprises a second partition plate 417 located in the second cavity 413, the second partition plate 417 is close to the air outlet 419, the gap of the second partition plate 417 is smaller than the particle size of the intermediate layer 2 material, the second partition plate 417 can prevent the intermediate layer material 101 from being blown out of the air outlet 419 by hot air, and the second partition plate 417 can limit the height of the intermediate layer material 101 in the second cavity 413, so as to prevent the intermediate layer material 101 from being blown up too high to contact the inner layer material 102.

[0061] The first fluidized bed 41 comprises a stirring rod 418, the stirring rod 418 can rotate, the stirring rod 418 is driven by a motor, the stirring rod 418 is located at the top of the first fluidized bed 41, the stirring rod 418 passes through the second partition plate 417, the stirring rod 418 extends downward, the stirring rod 418 is provided with a plurality of paddles 4181, the plurality of paddles 4181 are located below the second partition plate 417, the plurality of paddles 4181 are arranged along the length direction of the stirring rod 418, the paddles 4181 extend radially towards the stirring rod 418, the leaf surface of the paddles 4181 is inclined, when the stirring rod 418 rotates, the paddles 4181 can press the intermediate layer material 101 downward, so that the intermediate layer material 101 can better contact the inner layer material 102, the length of the paddles 4181 gradually decreases from top to bottom, due to the action of hot air, the particle density in the upper part of the second cavity 413 is smaller than that in the lower part, the paddles 4181 gradually increasing from bottom to top can correspond to the particle density in the second cavity 413, so that the stirring effect of the stirring rod 418 is better, the stirring rod 418 is provided with a scraper 4182, the upper edge of the scraper 4182 contacts the lower end surface of the second partition plate 417, the scraper 4182 can scrape the intermediate layer material 101 adsorbed on the lower end surface of the second partition plate 417 during the rotation of the stirring rod 418, so that the intermediate layer material 101 can be pressed downward by the paddles 4181, and the intermediate layer material 101 can be utilized more fully.

[0062] The fluidized bed device comprises a cooling tower and a second fan, the first fluidized bed 41 is provided with a discharge port, the discharge port is connected with the cooling tower, the second fan is connected with the cooling tower, the first partition plate 411 is inclined, the discharge port is located at the lower side of the first partition plate 411, the inclined first partition plate 411 can guide the inner layer material 102 coated with the intermediate layer material 101 to the discharge port, the discharge port is connected with the cooling tower, and the coated particles are cooled and stabilized in the intermediate layer 2 in the cooling tower. The cooling tower has a filtering and separating device, which can separate the residual intermediate layer material 101 from the coated material.

[0063] The first fluidized bed 41 and the exhaust pipe 5 are provided with a first valve 51, the second fluidized bed 42 and the exhaust pipe 5 are provided with a second valve 52, the first fluidized bed 41 and the second fluidized bed 42 are switched to operate, the operation mode of the first fluidized bed 41 and the second fluidized bed 42 is that the first valve 51 and the second valve 52 are both opened, when the first fluidized bed 41 completes coating of the inner layer material body 102, the hot air of the first fluidized bed 41 is closed, the second fluidized bed 42 is started, the discharge port of the first fluidized bed 41 is opened, the hot air of the second fluidized bed 42 passes through the first valve 51 and the second valve 52 to guide the material body particles in the first fluidized bed 41 to be sent out, and at the same time, the remaining intermediate layer material body 101 in the second cavity 413, the second partition plate 417 and the first partition plate 411 can be blown back into the first cavity 412, when the material body in the first fluidized bed 41 is emptied, the discharge port of the first fluidized bed 41 and the first valve 51 are closed, the first feeding port 415 and the second feeding port 416 are fed, the first valve 51 is opened after the second fluidized bed 42 completes coating after the feeding is completed, and the circulation is carried out in this way, the circulation work can be carried out without shutdown, and the production efficiency is higher.

[0064] S3, preparation of the outer layer 3: the mixture of the weathering aid and the lubricant is attached to the outer surface of the intermediate layer 2 to form the outer layer 3 by using the electrostatic spraying process, the electrostatic spraying process: the particles prepared in S2 are stirred in the stirred tank, and the mixture of the weathering aid and the lubricant is sprayed on the stirred particles through the electrostatic spraying head in the stirring process, and the mixture of the weathering aid and the lubricant is in paste form.

[0065] The above only describes the preferred embodiments of the present application, and the protection scope of the present application is not limited to the above-described embodiments, and any technical scheme falling within the concept of the present application belongs to the protection scope of the present application. It should be noted that, for ordinary skilled persons in the technical field, some improvements and decorations without departing from the principle of the present application are also considered as the protection scope of the present application.

Claims

1. A multi-layer composite polypropylene masterbatch, characterized in that, The inner layer (1), the intermediate layer (2), and the outer layer (3) are included, the intermediate layer (2) is coated on the outside of the inner layer (1), the outer layer (3) is coated on the outside of the intermediate layer (2), the weight percentage of the inner layer (1) is 50-60%, the weight percentage of the intermediate layer (2) is 20-30%, and the weight percentage of the outer layer (3) is 10-20%.

2. The multi-layered composite polypropylene masterbatch as claimed in claim 1, wherein, The inner layer (1) includes: Base resin: 50-70 parts of beta crystal polypropylene; Composite toughening agent: 10-20 parts of hydrogenated styrene-isobutylene-styrene, 5-15 parts of ethylene-octene copolymer, and 5-10 parts of ternary ethylene-propylene rubber; Nano-reinforced filler: 5-10 parts of nano calcium carbonate treated by silane coupling agent and 3-8 parts of nano barium sulfate; Interface modifier: 3-5 parts of maleic anhydride grafted polypropylene.

3. The multi-layered composite polypropylene masterbatch as claimed in claim 1, wherein, The intermediate layer (2) includes: Carrier resin: 70-80 parts of alpha crystal polypropylene; Dispersion system: hyperbranched polyester amide, including 5-10 parts of disulfide bond and 2-5 parts of polyethylene wax; Color powder pre-dispersion: 10-15 parts.

4. The multi-layered composite polypropylene masterbatch as claimed in claim 1, wherein, The outer layer (3) includes: Weathering aid: 1-2 parts of antioxidant 1010 and 0.5-1 part of ultraviolet absorber UV-531; Lubricant: 1-3 parts of calcium stearate.

5. A process for the preparation of the multilayered composite color masterbatch according to any one of claims 1 to 4, characterized in that, The steps include: S1, preparation of the inner layer (1): melt blending the base resin, the composite toughening agent, and the interface modifier in a double-screw extruder, adding the nano-reinforced filler, and extruding and granulating; S2, preparation of the intermediate layer (2): after high-speed mixing of the carrier resin, the hyperbranched polyester amide, and the color powder pre-dispersion, uniformly coating the outer surface of the inner layer (1) through a fluidized bed device; S3, preparation of the outer layer (3): using an electrostatic spraying process to attach the mixture of the weathering aid and the lubricant to the outer surface of the intermediate layer (2) to form the outer layer (3).

6. The preparation method according to claim 5, characterized in that, The fluidized bed device includes a first fluidized bed (41), a first fan, a heat source, and an exhaust pipe (5). The first fluidized bed (41) includes a first partition (411), an air inlet (414), and an air outlet (419). The first partition (411) divides the first fluidized bed (41) into a first cavity (412) and a second cavity (413). The first cavity (412) is used for feeding the intermediate layer material (101), and the second cavity (413) is used for feeding the inner layer material (102). The second cavity (413) is located above the first cavity (412). The aperture of the first partition (411) is larger than the particle size of the intermediate layer material (101) and smaller than the particle size of the inner layer material (102). The air inlet (414) is directed towards the bottom of the first cavity (412). The first fan is connected to the heat source, and the heat source is connected to the air inlet (414). The air outlet (419) is located at the top of the first fluidized bed (41), and the air outlet (419) is connected to the exhaust pipe (5).

7. The preparation method according to claim 6, characterized in that, The fluidized bed device comprises a cooling tower and a second fan, the first fluidized bed (41) is provided with a discharge port connected to the cooling tower, the second fan is connected to the cooling tower, and the first partition plate (411) is arranged obliquely, and the discharge port is located at the lower side of the first partition plate (411).

8. The preparation method according to claim 7, characterized in that, The fluidized bed device comprises a second fluidized bed (42) which has the same structure as the first fluidized bed (41), a first valve (51) is arranged between the first fluidized bed (41) and the exhaust pipe (5), a second valve (52) is arranged between the second fluidized bed (42) and the exhaust pipe (5), and the first fluidized bed (41) and the second fluidized bed (42) are switched to operate.

9. The preparation method according to claim 6, characterized in that, The first fluidized bed (41) comprises a second partition plate (417) located in the second cavity (413), the second partition plate (417) is close to the air outlet (419), and the gap of the second partition plate (417) is smaller than the particle size of the intermediate layer material (2).

10. The preparation method according to claim 9, characterized in that, The first fluidized bed (41) comprises a stirring rod (418) penetrating through the second partition plate (417), the stirring rod (418) extends downward, the stirring rod (418) is provided with a plurality of paddles (4181) arranged along the length direction of the stirring rod (418), the paddles (4181) extend radially towards the stirring rod (418), the length of the paddles (4181) gradually decreases from top to bottom, and the stirring rod (418) is provided with a scraper (4182) with an upper edge contacting the lower end surface of the second partition plate (417).

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