A stone-plastic composite material and preparation method thereof

Abstract

The present invention belongs to the field of stone-plastic composite materials and specifically discloses a stone-plastic composite material and a preparation method thereof. The present invention utilizes surface modification technology for inorganic fillers to achieve composite modification of various polymers and inorganic fillers, thereby improving the compatibility of the inorganic fillers with plastics. This results in a stone-plastic composite material having both good appearance and mechanical properties, enhancing the overall performance of the material, enabling it to meet the performance requirements for use in high-end plastic products. This overcomes the limitation that inorganic fillers can only be used as filling materials for low-end plastic products, significantly reduces the production cost of engineering plastics, reduces the consumption of petroleum resources, and expands the application space for inorganic fillers.

Description

Technical Field

[0001] The invention belongs to the field of stone-plastic composite materials, and particularly relates to a stone-plastic composite material and a preparation method thereof. Background Art

[0002] In the high-tech era, plastics, as a new type of man-made material, have become a key pillar of economic and technological development. Global annual plastic production currently exceeds 300 million tons. With the rapid development of the plastics industry, a growing number of manufacturers have emerged, and a diverse range of products have penetrated various fields, with new products, new designs, and new functions constantly emerging. While these products meet industrial needs and enrich people's lives, they also consume a large amount of increasingly depleted non-renewable petroleum resources. As a result, the price of plastic resins has risen sharply, creating fierce price competition for a large number of plastics manufacturers. Many companies are striving to continuously improve the performance of plastics while further reducing costs. At the same time, plastic products made from these pure plastic resins generate a large amount of environmentally unacceptable waste after use, creating a large amount of "white waste" and causing significant environmental pollution problems. Balancing industrial applications, reducing production costs, conserving petroleum resources, and protecting the environment has become a major challenge for the survival and development of the current plastics industry.

[0003] Stone-plastic composite modification technology may be a viable solution to this problem. This technology primarily involves using a specialized polymer blending modification technique to combine a plastic matrix resin with inorganic powders made from inexpensive minerals to create a polymer-stone-plastic composite material. This composite material, when used in the production of plastic products, must meet diverse technical requirements. This requires the addition of different mineral powders in varying amounts to achieve one or more of these requirements. In addition to reducing costs, mineral powders can also improve the processing properties of plastics and impart specific physical and chemical properties. Different mineral powders have varying modification functions, such as enhancing the material's rigidity and dimensional stability, compressive and impact resistance, corrosion resistance, electrical insulation, reducing shrinkage, improving heat resistance, improving light dispersion, odor absorption, scratch resistance, and smoothness. Therefore, an ideal polymer-stone-plastic composite material could significantly reduce the production cost of plastic products while also improving their physical properties, while also conserving significant amounts of petroleum resources. Furthermore, since these materials contain a large amount of inorganic powder, they will disintegrate into fragments when exposed to light in natural conditions after use. After a period of exposure to light, they will turn into powder, thus reducing white pollution. Therefore, polymer stone-plastic composite materials will play an important role in the future rapid development of the plastics industry.

[0004] Currently, polymer-plastic composites are divided into two categories: one is calcium carbonate-filled polyvinyl chloride, primarily used in the production of plastic flooring; the other is a low-end calcium carbonate-filled polyolefin filler. This filler is made from calcium carbonate-filled general-purpose plastic polyolefin resin. Therefore, polymer-plastic composites also belong to a category of inorganic powder filler materials, but they still have many shortcomings. For example, they suffer from poor filler dispersion, low filler loading, agglomeration points, flow marks, odor, surface precipitation, and poor finish in finished products. Furthermore, the overall performance of plastic products decreases sharply when filler loading exceeds 20%. This has limited the promotion and application of polymer-plastic composites in the high-tech plastics industry, restricted the development of plastic products in this field, and brought high costs to high-end plastic product manufacturers, while preventing a significant reduction in plastic usage.

[0005] In order to increase the compatibility of fillers and plastics in existing polymer stone-plastic composite materials, a small molecule coating is generally formed on the surface of the mineral powder before it is composited with the plastic. The organic chain segments of this coating are short. Under the high-temperature processing conditions of the polymer, many of them will be decomposed into gases and discharged from the polymer. Therefore, the groups that can react chemically with the polymer material are greatly reduced, resulting in a decrease in the interfacial compatibility between the inorganic powder and the high-molecular organic polymer. This cannot effectively solve the problem of poor compatibility between the filler and the plastic, resulting in poor toughness. In addition, conventional technologies still have the phenomenon of unpleasant odor, surface precipitation, powder agglomeration crystal points, rough product surface, and reduced overall performance when producing plastic products. These problems further lead to a very low filler addition amount, which fails to achieve the goal of reducing production costs. Therefore, it is still necessary to develop a method that can increase the compatibility of fillers and plastics and achieve a high filling amount, thereby achieving the good overall performance of stone-plastic composite materials and meeting the toughness performance requirements of high-end plastic products. Summary of the Invention

[0006] In order to solve the problems of the prior art mentioned above, such as the compatibility of fillers and plastics and the poor comprehensive physical properties of products, the present invention provides a stone-plastic composite material and a preparation method thereof through surface modification technology.

[0007] To achieve the above objectives, the following technical solutions are specifically included:

[0008] A stone-plastic composite material comprises the following raw materials in parts by weight: 30-90 parts of an inorganic filler, 10-70 parts of a polymer, 0.5-4.5 parts of a powder surface modifier, 0.01-1 parts of a chain extender, 0.01-3 parts of a modifier, and 1-3 parts of a lubricant;

[0009] The powder surface modifier includes at least one of a cyclic-chain multipolymer hyperdispersant, a polycaprolactone polyol-polyethyleneimine block copolymer dispersant, an acrylate polymer dispersant, a polyurethane polymer dispersant, a polyester polymer dispersant, a composite macromolecular polymer modifier, and a coupling agent; the coupling agent includes a coupling agent containing rare earth elements.

[0010] In existing stone-plastic composite materials, inorganic fillers are generally modified using titanate coupling agents, aluminate coupling agents, silane coupling agents, etc. As described in the background art above, these coupling agents are all low-molecular compounds. Therefore, after the inorganic filler is modified, a small molecular coating is formed on its surface. The organic chain segments of this coating are short. Under the high-temperature processing conditions of the polymer, many of them will be thermally decomposed and discharged as gas, greatly reducing the groups that can chemically react with the polymer material, resulting in poor interfacial compatibility between the inorganic filler and the high-molecular organic polymer. The present invention, on the other hand, uses a powder surface modifier with a high-molecular chain segment to perform surface activation modification on the inorganic filler. The powder surface modifier is selected from a macromolecular polymer of the specific substance type. The specifically selected powder surface modifier can introduce a large number of irreversible organic functional groups on the surface of the inorganic filler, so that the macromolecular organic functional groups of the polymer form good compatibility with the inorganic filler and form a good bond with the matrix plastic. This can greatly increase the amount of inorganic filler added to the composite material, and the composite material has better overall properties such as mechanical properties and appearance properties.

[0011] As a preferred embodiment of the present invention, the powder surface modifier includes at least one of the ring-chain multipolymer modifier LD-1019 and the composite macromolecular polymer modifier LD-300P.

[0012] As a preferred embodiment of the present invention, the polymer includes at least one of high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), polypropylene (PP), acrylonitrile-butadiene-styrene copolymer (ABS), polystyrene (PS), polyethylene terephthalate (PET), polycarbonate (PC), nylon (PA), polybutylene terephthalate (PBT), and polyoxymethylene (POM). The above-mentioned polymer matrix can have good compatibility with the modified inorganic filler of the present invention.

[0013] As a preferred embodiment of the present invention, the inorganic filler includes at least one of calcium carbonate, talc, diatomaceous earth, mica powder, kaolin, and wollastonite.

[0014] As a preferred embodiment of the present invention, the particle size of the inorganic filler is 600-2500 mesh.

[0015] The above-mentioned inorganic fillers are generally also called mineral powders, which are all mineral powders commonly used for plastic modification. Different mineral powders have different modification functions on plastic products. A single, two or more composite mineral powders can be used. Different mineral powder solutions can be selected according to the actual product performance requirements.

[0016] As a preferred embodiment of the present invention, the powder surface modifier further includes a coupling agent. The powder surface modifier described herein preferably further includes a coupling agent. The addition of the coupling agent can cooperate with the specific substance of the powder surface modifier described above to modify the surface of the inorganic filler, thereby introducing a large number of irreversible organic functional groups and ionic coordination bonds on the surface of the inorganic filler. This further improves the compatibility between the macromolecular organic functional groups of the polymer and the inorganic filler, further increasing the amount of inorganic filler added to the composite material, enhancing the tensile strength of the stone-plastic composite material, and maintaining good toughness.

[0017] As a further preferred embodiment of the present invention, the coupling agent further includes at least one of a titanate coupling agent, an aluminate coupling agent, a silane coupling agent, and an aluminum-zirconium composite coupling agent.

[0018] As a more preferred embodiment of the present invention, the coupling agent containing rare earth elements is at least one of a rare earth coupling agent and a rare earth aluminum titanium composite coupling agent.

[0019] In some embodiments of the present invention, the aluminum-zirconium composite coupling agent can be selected from at least one of the models LD-139-1, LD-139-4, TL-2, TL-3A, TL-4, and TL-6; the rare earth coupling agent can be selected from the model WOT-108; and the rare earth aluminum-titanium composite coupling agent can be selected from at least one of the models F-1, 411, and F-2.

[0020] In some embodiments of the present invention, the titanate coupling agent may be selected from at least one of the following models: LD-22, QX-131, JTW-133, and LK-201.

[0021] In some embodiments of the present invention, the aluminate coupling agent may be specifically selected as model LD-B-1.

[0022] The coupling agent in the powder surface modifier of the present invention can be selected from at least one of a titanate coupling agent, an aluminate coupling agent, a silane coupling agent, an aluminum-zirconium composite coupling agent, and a coupling agent containing a rare earth element. More preferably, the coupling agent is an aluminum-zirconium composite coupling agent or a coupling agent containing a rare earth element. When the coupling agent is selected from at least one of a rare earth aluminum-zirconium composite coupling agent or a coupling agent containing a rare earth element, a large number of irreversible organic functional groups can be introduced onto the surface of the inorganic filler through the chelation effect between aluminum and zirconium and the coordination effect of the valence electrons of the rare earth, thereby further introducing a large number of ionic coordination bonds. This significantly improves the compatibility between the macromolecular organic functional groups of the polymer and the inorganic filler, greatly increases the amount of inorganic filler added to the composite material, enhances the tensile strength of the stone-plastic composite material, and maintains good toughness.

[0023] As a preferred embodiment of the present invention, the chain extender includes at least one of an oxazoline chain extender and an isocyanate chain extender.

[0024] As a further preferred embodiment of the present invention, the oxazoline chain extender includes at least one of 2,2-bis(2-oxazoline) (BOZ) and 2,2-(1,3-phenylene)-bis(2-oxazoline) (PBO); the isocyanate chain extender includes at least one of diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HDI), 2,6-diisocyanate (TDI), and 1,5-naphthalene diisocyanate (NDI).

[0025] The chain extender in the system makes the organic small molecule chains on the surface of the inorganic filler grow and extend. The chain extender forms a "bridge" between the polymer chain and the inorganic filler coated on the surface, realizing the mutual entanglement of the molecular chains between the polymer and the inorganic filler, enhancing the melt strength of the composite material, and increasing the filling amount, thereby achieving the purpose of improving the mechanical properties and processing properties of the material, reducing the production cost of plastic products and saving the consumption of plastic resin.

[0026] As a preferred embodiment of the present invention, the modifier includes at least one of methyl methacrylate-butadiene-styrene terpolymer (MBS), polyolefin elastomer (POE) and glycidyl methacrylate (GMA).

[0027] As a further preferred embodiment of the present invention, the methyl methacrylate-butadiene-styrene terpolymer (MBS) includes at least one of the models B-621, B-564, B-621, B-621, B-621, EXL2690, M701, M210, M722, and M611P.

[0028] As a further preferred embodiment of the present invention, the polyolefin elastomer (POE) includes at least one of models 6501 and 7467.

[0029] As a further preferred embodiment of the present invention, the glycidyl methacrylate (GMA) comprises at least one of POE-g-GMA, EMA-g-GMA, EVA-g-GMA, EBA-g-GMA, and PE-g-GMA. Even more preferably, the glycidyl methacrylate comprises a mixture of one or more of the following types: TPW, W5A, W5A-2, DB4170, and W5D.

[0030] The present invention selects the above modifiers mainly for strengthening and toughening the polymer, and can also increase the melt strength of inorganic fillers and polymers, and improve the comprehensive physical properties of the products.

[0031] As a preferred embodiment of the present invention, the lubricant includes at least one of a fatty acid lubricant, an amide lubricant, and a hydrocarbon lubricant. The fatty acid lubricant includes but is not limited to stearic acid; the amide lubricant includes but is not limited to at least one of oleamide, stearamide, ethylene bisstearamide, and ethylene bisstearamide; and the hydrocarbon lubricant includes but is not limited to at least one of paraffin wax, polyethylene wax, low molecular weight polypropylene wax, and chlorinated polyethylene wax.

[0032] A method for preparing a stone-plastic composite material comprises the following steps:

[0033] (1) performing a modification reaction on the dried inorganic filler and the powder surface modifier to obtain a modified inorganic filler;

[0034] (2) adding a chain extender to carry out a chain extension reaction, and then sequentially adding a polymer, a modifier, and a lubricant to blend under stirring;

[0035] (3) The blended materials are sequentially subjected to melt blending and extrusion granulation to obtain the stone-plastic composite material.

[0036] As a preferred embodiment of the present invention, in step (1), the moisture content of the dried inorganic filler is ≤0.3%.

[0037] As a preferred embodiment of the present invention, in step (1), the drying temperature is 70-135° C., and the drying time is 30-60 minutes.

[0038] As a preferred embodiment of the present invention, in step (1), the temperature of the modification reaction is 70-135° C., and the time of the modification reaction is 1-60 minutes.

[0039] As a preferred embodiment of the present invention, in step (2), the temperature of the chain extension reaction is 70-135° C., and the time of the chain extension reaction is 1-60 minutes.

[0040] As a preferred embodiment of the present invention, in step (2), the blending temperature is 70-135° C., and the blending time is 1-60 minutes.

[0041] As a preferred embodiment of the present invention, in step (3), the temperature of the melt blending is 150-290°C, and the time of the melt blending is 15-60 minutes.

[0042] As a preferred embodiment of the present invention, in step (3), the temperature of the extrusion granulation is 130-295°C.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] (1) The present invention adopts a powder surface modifier to perform surface activation modification on the inorganic filler, and introduces a large number of irreversible organic functional groups on the surface of the inorganic filler, so that the macromolecular organic functional groups of the polymer and the inorganic filler have good interface compatibility, which can greatly increase the addition amount of inorganic filler in the composite material, enhance the tensile strength of the stone-plastic composite material, and maintain good toughness.

[0045] (2) The chain extender of the present invention enables the organic small molecule chains on the surface of the inorganic filler to grow and extend. The chain extender forms a "bridge" between the polymer chain and the inorganic filler coated on the surface, thereby achieving mutual entanglement of the molecular chains between the polymer and the inorganic filler, enhancing the melt strength of the composite material, and increasing the filling amount, thereby achieving the purpose of improving the mechanical properties and processing properties of the material, reducing the production cost of plastic products and saving the consumption of plastic resin.

[0046] (3) The present invention realizes the composite modification of various high molecular polymers and inorganic fillers through the surface modification technology of inorganic fillers, improves the compatibility of inorganic fillers with plastics, and produces a stone-plastic composite material with good appearance and mechanical properties, thereby improving the comprehensive performance of this type of material, so that it can meet the performance requirements when used in high-end plastic products, breaking the limitation that inorganic fillers can only be used as filling materials for low-end plastic products, and at the same time greatly reducing the production cost of engineering plastics, reducing the consumption of petroleum resources, and expanding the application space of inorganic fillers. DETAILED DESCRIPTION

[0047] To better illustrate the objectives, technical solutions, and advantages of the present invention, the present invention will be further described below with reference to specific examples. The experimental methods used in the examples and / or comparative examples are conventional methods unless otherwise specified; the materials and reagents used are commercially available unless otherwise specified.

[0048] The raw materials used in the following examples and comparative examples are all in parts by weight.

[0049] Some of the raw material information involved in the following examples and comparative examples:

[0050] Coupling agent: aluminum-zirconium composite coupling agent LD-139-1, TL-3A, LD-139-4, TL-6, TL-4; rare earth coupling agent WOT-108 (purchased from Guangdong Weilin); rare earth aluminum-titanium composite coupling agent F-1 (purchased from Hangzhou Jessica), F-2 (purchased from Tianchang Green Chemical), 411 (purchased from Foshan Shengyi); titanate coupling agent LK-201 (purchased from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd.).

[0051] Dispersants or modifiers: cyclic-chain multi-polymer hyperdispersant LD-1019 and composite macromolecular polymer modifier LD-300P, purchased from Lida Chemical.

[0052] Example 1

[0053] A method for preparing a polymer stone-plastic composite material, comprising the following specific steps:

[0054] 1) 50 parts of calcium carbonate with a particle size of 1500 mesh were selected and placed in a 10-liter high-speed blender at 120° C. and dried at high speed for 40 minutes. The moisture content was detected to be ≤0.3%;

[0055] 2) Add one portion of the ring-chain multi-polymer hyperdispersant LD-1019 into a dry ore powder high-speed mixer and perform a modification and activation reaction at 120°C under high-speed stirring for 10 minutes;

[0056] 3) Add 0.5 parts of diphenylmethane diisocyanate (MDI) chain extender into the activated high-speed mixer and carry out the chain extension reaction at 120°C under high-speed stirring for 5 minutes;

[0057] 4) 50 parts of weighed high-density polyethylene (HDPE, Yangzi Petrochemical 5000S) were added to a high-speed mixer after the activation chain extension reaction and stirred at 120°C for 2 minutes to blend;

[0058] 5) 1 part of methyl methacrylate-butadiene-styrene terpolymer (MBS) EXL2620, 1 part of POE-g-GMA modifier, 1 part of stearic acid and 1 part of paraffin were blended at high speed at 120° C. for 10 minutes;

[0059] 6) Cooling the material with water until the temperature drops to 35° C., then putting the material into a 170° C. internal mixer for melt blending and internal mixing for 30 minutes. After the material becomes a viscous mass with a smooth surface, the material is transported to a forced feeder and forced fed into a 160° C. single-screw extruder for extrusion granulation; the extruded pellets are cooled by air to below 30° C. and enter a storage bin, thereby obtaining the stone-plastic composite material pellets.

[0060] Example 2

[0061] The only difference between this embodiment and embodiment 1 is that one part of the cyclic multi-polymer hyperdispersant LD-1019 is replaced by one part of the composite macromolecular polymer modifier LD-300P.

[0062] Example 3

[0063] The only difference between this embodiment and embodiment 1 is that 1 part of the cyclic chain multipolymer hyperdispersant LD-1019 is replaced by 0.5 parts of titanate coupling agent LK-201 and 0.5 parts of the cyclic chain multipolymer hyperdispersant LD-1019.

[0064] Example 4

[0065] The only difference between this embodiment and embodiment 1 is that 1 part of the cyclic chain multipolymer hyperdispersant LD-1019 is replaced by 0.5 parts of rare earth coupling agent WOT-108 and 0.5 parts of cyclic chain multipolymer hyperdispersant LD-1019.

[0066] Example 5

[0067] The only difference between this embodiment and embodiment 1 is that 1 part of the cyclic chain multipolymer hyperdispersant LD-1019 is replaced by 0.5 parts of rare earth aluminum titanium composite coupling agent F-2 and 0.5 parts of the cyclic chain multipolymer hyperdispersant LD-1019.

[0068] Example 6

[0069] The only difference between this embodiment and embodiment 1 is that 1 part of the cyclic chain multipolymer hyperdispersant LD-1019 is replaced by 0.5 parts of the aluminum zirconium composite coupling agent LD-139-1 and 0.5 parts of the cyclic chain multipolymer hyperdispersant LD-1019.

[0070] Example 7

[0071] The only difference between this embodiment and embodiment 2 is that 1 part of the composite macromolecular polymer modifier LD-300P is replaced by 0.5 parts of the titanate coupling agent LK-201 and 0.5 parts of the composite macromolecular polymer modifier LD-300P.

[0072] Example 8

[0073] The only difference between this embodiment and embodiment 2 is that 1 part of the composite macromolecular polymer modifier LD-300P is replaced by 0.5 parts of rare earth coupling agent WOT-108 and 0.5 parts of the composite macromolecular polymer modifier LD-300P.

[0074] Example 9

[0075] The only difference between this embodiment and embodiment 2 is that 1 part of the composite macromolecular polymer modifier LD-300P is replaced by 0.5 parts of the rare earth aluminum titanium composite coupling agent F-2 and 0.5 parts of the composite macromolecular polymer modifier LD-300P.

[0076] Example 10

[0077] The only difference between this embodiment and embodiment 2 is that 1 part of the composite macromolecular polymer modifier LD-300P is replaced by 0.5 parts of the aluminum-zirconium composite coupling agent LD-139-1 and 0.5 parts of the composite macromolecular polymer modifier LD-300P.

[0078] Example 11

[0079] The only difference between this embodiment and embodiment 1 is that 1 part of the cyclic chain multipolymer hyperdispersant LD-1019 is replaced by 0.5 parts of the composite macromolecular polymer modifier LD-300P and 0.5 parts of the cyclic chain multipolymer hyperdispersant LD-1019.

[0080] Example 12

[0081] The only difference between this embodiment and embodiment 1 is that the amount of the ring-chain multi-polymer hyperdispersant LD-1019 is increased from 1 part to 1.5 parts.

[0082] Example 13

[0083] The only difference between this embodiment and embodiment 12 is that 1.5 parts of the cyclic chain multipolymer hyperdispersant LD-1019 are replaced by 0.5 parts of the composite macromolecular polymer modifier LD-300P, 0.5 parts of the cyclic chain multipolymer hyperdispersant LD-1019 and 0.5 parts of the titanate coupling agent LK-201.

[0084] Example 14

[0085] The only difference between this embodiment and embodiment 12 is that 1.5 parts of the cyclic chain multipolymer hyperdispersant LD-1019 are replaced by 0.5 parts of the composite macromolecular polymer modifier LD-300P, 0.5 parts of the cyclic chain multipolymer hyperdispersant LD-1019 and 0.5 parts of the rare earth coupling agent WOT-108.

[0086] Example 15

[0087] The only difference between this embodiment and embodiment 12 is that 1.5 parts of the cyclic-chain multipolymer hyperdispersant LD-1019 are replaced by 0.5 parts of the composite macromolecular polymer modifier LD-300P, 0.5 parts of the cyclic-chain multipolymer hyperdispersant LD-1019 and 0.5 parts of the aluminum-zirconium composite coupling agent LD-139-1.

[0088] Example 16

[0089] The only difference between this embodiment and Example 12 is that 1.5 parts of the cyclic chain multipolymer hyperdispersant LD-1019 are replaced by 0.5 parts of the composite macromolecular polymer modifier LD-300P, 0.5 parts of the cyclic chain multipolymer hyperdispersant LD-1019, 0.25 parts of the aluminum zirconium composite coupling agent LD-139-1 and 0.25 parts of the rare earth coupling agent WOT-108.

[0090] Example 17

[0091] The only difference between this embodiment and embodiment 1 is that 1 part of methyl methacrylate-butadiene-styrene terpolymer (MBS) EXL2620 and 1 part of POE-g-GMA modifier are replaced by 2 parts of methyl methacrylate-butadiene-styrene terpolymer (MBS) EXL2620 in equal amounts.

[0092] Example 18

[0093] The only difference between this embodiment and embodiment 1 is that the inorganic filler is 30 parts and the high-density polyethylene is 70 parts.

[0094] Example 19

[0095] The only difference between this embodiment and embodiment 1 is that the inorganic filler is 70 parts and the high-density polyethylene is 30 parts.

[0096] Example 20

[0097] The only difference between this embodiment and embodiment 1 is that 0.5 parts of diphenylmethane diisocyanate (MDI) chain extender is replaced by 0.5 parts of 2,2-bis(2-oxazoline) (BOZ) chain extender.

[0098] Example 21

[0099] The only difference between this comparative example and Example 1 is that one part of the cyclic chain multipolymer hyperdispersant LD-1019 is replaced by one part of the rare earth coupling agent WOT-108.

[0100] Example 22

[0101] A method for preparing a polymer stone-plastic composite material, comprising the following specific steps:

[0102] 1) 50 parts of talcum powder with a particle size of 1500 mesh were selected and placed in a 10-liter high-speed blender at 125°C for 40 minutes to dry at a high speed. The moisture content was measured to be ≤0.2%.

[0103] 2) Add 0.6 parts of aluminum-zirconium composite coupling agent TL-3A, 0.7 parts of rare earth aluminum-titanium composite coupling agent F-1 and 1 part of composite macromolecular polymer modifier LD-300P into a dry ore powder high-speed mixer, stir at high speed for 8 minutes, and activate at 125°C;

[0104] 3) Add 0.8 parts of 2,2-bis(2-oxazoline) (BOZ) chain extender into the activated high-speed mixer and stir at high speed for 4 minutes at 125°C to carry out the chain extension reaction;

[0105] 4) 40 parts of polypropylene (PP), 5 parts of acrylonitrile-butadiene-styrene copolymer (ABS) and 5 parts of linear low-density polyethylene (LDPE) were weighed and placed in a high-speed blender, stirred at high speed for 3 minutes, and blended at 125°C for modification;

[0106] 5) 1 part of POE modifier 6501, 0.5 parts of glycidyl methacrylate (GMA) modifier DB4170 and MBS modifier M722, 0.8 parts of oleamide lubricant and chlorinated polyethylene wax lubricant were weighed and put into a high-speed blending mixer and blended for 15 minutes at a temperature of 125°C;

[0107] 6) Cool the material with water until the temperature drops to 35°C, then put the material into a 180°C internal mixer for melt blending and internal mixing for 30 minutes. After the material is in a viscous block state with a smooth surface, the material is transported to a forced feeder and forced fed into a 170°C single-screw extruder for extrusion granulation. The extruded pellets are cooled by air to below 30°C and then enter the storage bin to obtain stone-plastic composite material pellets.

[0108] Example 23

[0109] A method for preparing a polymer stone-plastic composite material, comprising the following specific steps:

[0110] 1) 30 parts of 1500 mesh wollastonite and 20 parts of 1500 mesh calcium carbonate were placed in a 10-liter high-speed blender and dried at 115°C for 40 minutes. The moisture content was detected to be ≤0.2%.

[0111] 2) 0.5 parts of aluminum-zirconium composite coupling agent LD-139-4, 0.6 parts of rare earth aluminum-titanium composite coupling agent F-2, and 1 part of composite macromolecular polymer modifier LD-300P were weighed and put into a dry ore powder high-speed mixer, stirred at high speed for 10 minutes, and activated at a temperature of 115°C;

[0112] 3) Add 0.2 parts of hexamethylene diisocyanate (HDI) and 0.3 parts of 2,6-diisocyanate (TDI) chain extender into the activated high-speed mixer and stir at high speed for 5 minutes at 115°C for chain extension reaction;

[0113] 4) Add 45 parts of weighed polystyrene (PS) and 5 parts of acrylonitrile-butadiene-styrene copolymer (ABS) into a high-speed mixer after the activation and chain extension reaction, stir at high speed for 2 minutes, and blend at high speed at 115°C;

[0114] 5) 0.8 parts of weighed methyl methacrylate-butadiene-styrene terpolymer (MBS) M611P modifier, 1 part of glycidyl methacrylate (GMA) EMA-g-GMA modifier, 1 part of polyethylene wax lubricant, and 1 part of ethylene bisstearamide lubricant were blended at high speed for 10 minutes at 115°C;

[0115] 6) Cool the material with water until the temperature drops to 35°C, then put the material into a 185°C internal mixer for melt blending and internal mixing for 30 minutes. After the material is in a viscous block state with a smooth surface, the material is transported to a forced feeder and forced fed into a 170°C single-screw extruder for extrusion granulation. The extruded pellets are cooled by air to below 30°C and enter the storage bin to obtain stone-plastic composite material pellets.

[0116] Example 24

[0117] A method for preparing a polymer stone-plastic composite material, comprising the following specific steps:

[0118] 1) 30 parts of 2000 mesh talc and 10 parts of 2000 mesh kaolin were placed in a 10-liter high-speed blender and dried at 130°C for 40 minutes. The moisture content was ≤ 0.1%.

[0119] 2) 0.6 parts of aluminum-zirconium composite coupling agent TL-6, 0.9 parts of rare earth aluminum-titanium composite coupling agent 411 and 1 part of ring-chain multipolymer dispersant LD-1019 were weighed and put into a dry ore powder high-speed mixer, stirred at high speed for 10 minutes, and activated at 130°C;

[0120] 3) Add 0.8 parts of 1,5-naphthalene diisocyanate (NDI) chain extender into the high-speed mixer during activation and stir at high speed for 5 minutes at 130°C for activation and chain extension reaction;

[0121] 4) 55 parts of weighed polybutylene terephthalate (PBT) and 5 parts of polyethylene terephthalate (PET) were added to a high-speed mixer after the chain extension reaction was activated, and stirred at high speed for 2 minutes at 130°C for high-speed blending;

[0122] 5) 1.2 parts of glycidyl methacrylate (GMA) EBA-g-GMA modifier, 0.8 parts of polyolefin elastomer (POE) 7467 modifier, 1 part of ethylene bisstearamide lubricant and 1 part of chlorinated polyethylene wax lubricant were weighed and high-speed blended for 10 minutes at 130°C;

[0123] 6) Cool the material with water until the temperature drops to 35°C, then put the material into a 185°C internal mixer for melt blending and internal mixing for 30 minutes. After the material is in a viscous block state with a smooth surface, the material is transported to a forced feeder and forced fed into a 170°C single-screw extruder for extrusion granulation. The extruded pellets are cooled by air to below 30°C and enter the storage bin to obtain stone-plastic composite material pellets.

[0124] Example 25

[0125] A method for preparing a polymer stone-plastic composite material, comprising the following specific steps:

[0126] 1) 30 parts of 2500 mesh calcium carbonate and 5 parts of 2000 mesh kaolin were placed in a 10-liter high-speed blender and dried at 135°C for 40 minutes. The moisture content was detected to be ≤0.1%.

[0127] 2) 0.6 parts of aluminum-zirconium composite coupling agent TL-4, 1 part of rare earth aluminum-titanium composite coupling agent F-2 and 1 part of composite macromolecular polymer modifier LD-300P were weighed and put into a dry ore powder high-speed mixer, stirred at high speed for 10 minutes, and activated at 135°C;

[0128] 3) Add 0.8 parts of 2,2-(1,3-phenylene)-bis(2-oxazoline) (PBO) chain extender into the high-speed mixer during activation and stir at high speed for 5 minutes at 135°C for activation and chain extension reaction;

[0129] 4) Add 60 parts of polycarbonate (PC) and 5 parts of nylon (PA) into a high-speed mixer after the activation chain extension reaction, stir at high speed for 3 minutes, and blend at high speed at 135°C;

[0130] 5) 1 part of glycidyl methacrylate (GMA) EMA-g-GMA modifier, 0.8 part of methyl methacrylate-butadiene-styrene terpolymer (MBS) B-564 modifier, 1 part of ethylene bisstearamide lubricant, and 1 part of chlorinated polyethylene wax lubricant were weighed and blended at high speed for 10 minutes at 135°C;

[0131] 6) Cool the material with water until the temperature drops to 35°C, then put the material into a 285°C internal mixer for melt blending and internal mixing for 30 minutes. After the material is in a viscous block state with a smooth surface, the material is transported to a forced feeder and forced fed into a 270°C twin-screw extruder for extrusion granulation. The extruded pellets are cooled by air to below 30°C and enter the storage bin to obtain stone-plastic composite material pellets.

[0132] Example 26

[0133] The only difference between this embodiment and embodiment 1 is that the inorganic filler is 90 parts and the high-density polyethylene is 10 parts.

[0134] Comparative Example 1

[0135] The only difference between this comparative example and Example 1 is that one part of the cyclic chain multipolymer hyperdispersant LD-1019 is replaced by one part of the aluminum-zirconium composite coupling agent LD-139-1.

[0136] Comparative Example 2

[0137] The only difference between this comparative example and Example 1 is that one part of the cyclic chain multipolymer hyperdispersant LD-1019 is replaced by one part of the titanate coupling agent LK-201.

[0138] Comparative Example 3

[0139] The only difference between this comparative example and Example 1 is that step (2) is not performed and no powder surface modifier is added.

[0140] Comparative Example 4

[0141] The only difference between this comparative example and Example 1 is that step (3) is not performed and phenylmethane diisocyanate (MDI) chain extender is not added to carry out the chain extension reaction.

[0142] Performance testing of stone-plastic composite materials

[0143] Tensile strength and elongation at break: The tensile strength and elongation at break of the material are tested in accordance with the method in the standard GB / T-1040.2-2006, Determination of tensile properties of plastics Part 2: Test conditions for molded and extruded plastics.

[0144] Table 1

[0145]

[0146] It can be seen from Examples 1, 2 and 21 that the composite macromolecular polymer modifier has a better modification effect on the material than the chain multi-polymer hyperdispersant and the coupling agent containing rare earth elements, and can more significantly improve the compatibility and tensile strength of the material and maintain the toughness of the material.

[0147] It can be seen from Examples 1-2 and 11 that when a composite macromolecular polymer modifier and a chain multi-polymer hyperdispersant are used simultaneously in the powder surface modifier, more irreversible organic functional groups are introduced on the surface of the inorganic filler, which has a better modification effect on the material, can greatly improve the tensile strength of the stone-plastic composite material, and maintain the material's good toughness.

[0148] As can be seen from Examples 1 and 3-6, and Examples 2 and 7-10, when a chain-type multi-polymer hyperdispersant is compounded with a coupling agent, or a composite macromolecular polymer modifier is compounded with a coupling agent, the surface modification effect of the material can be further enhanced. The coupling agent can be selected from at least one of a titanate coupling agent, an aluminate coupling agent, a silane coupling agent, an aluminum-zirconium composite coupling agent, and a coupling agent containing a rare earth element. When the coupling agent is an aluminum-zirconium composite coupling agent or a coupling agent containing a rare earth element, these coupling agents can introduce a large number of irreversible organic functional groups on the surface of the inorganic filler through the chelation effect between aluminum and zirconium and the coordination effect of the valence electrons of the rare earth, further introducing a large number of ionic coordination bonds. This significantly improves the compatibility between the macromolecular organic functional groups of the polymer and the inorganic filler, greatly increasing the amount of inorganic filler added to the composite material, enhancing the tensile strength of the stone-plastic composite material, and maintaining good toughness. Therefore, aluminum-zirconium composite coupling agents and coupling agents containing rare earth elements are more preferred.

[0149] It can be seen from Examples 1 and 12 that increasing the amount of powder surface modifier can further increase the number of irreversible organic functional groups introduced on the surface of the inorganic filler, improve the compatibility between the components, and have a better modification effect on the material. It can greatly improve the compatibility and tensile strength of the stone-plastic composite material and maintain good toughness.

[0150] As can be seen from Examples 12-16, the surface activation modification scheme of the inorganic filler using a coupling agent, a dispersant and a modifier at the same time is the best. A large number of irreversible organic functional groups and / or metal ion coordination bonds are introduced on the surface of the inorganic filler, so that the macromolecular organic functional groups of the polymer and the inorganic filler have better compatibility, which can significantly enhance the compatibility and tensile strength of the stone-plastic composite material and maintain good toughness.

[0151] It can be seen from Example 1 and Comparative Examples 1-3 that no surface modification is performed or a conventional titanate coupling agent or aluminum-zirconium composite coupling agent is simply used, because these are small molecule polymers, the coating modification effect on the filler is relatively poor, resulting in poor compatibility between the components. Therefore, it can also be reflected that the present invention can significantly improve the compatibility and tensile strength of the material and maintain good toughness by adding a powder surface modifier with a polymer chain segment for modification.

[0152] It can be seen from Examples 1 and 17 that when MBS and POE-g-GMA are used simultaneously, the modification effect on the material is better, and the compatibility and tensile strength of the material can be further improved while maintaining good toughness.

[0153] From the comparison between Example 1 and Comparative Example 4, it can be seen that the chain extender is used to extend the material. The chain extender causes the organic small molecule chain on the surface of the inorganic filler to grow and extend. The chain extender forms a "bridge" between the polymer chain and the inorganic filler coated on the surface, thereby achieving mutual entanglement of the molecular chains between the polymer and the inorganic filler, enhancing the melt strength of the composite material, and increasing the filling amount, thereby achieving the purpose of improving the mechanical properties and processing properties of the material, reducing the production cost of plastic products, and saving plastic resin consumption.

[0154] In addition, it can be seen from Examples 1 and 20 that the effects of diphenylmethane diisocyanate chain extender and 2,2-bis(2-oxazoline) (BOZ) chain extender are similar, and both can be used as chain extenders in the system of the present invention to achieve the technical effects of the present invention.

[0155] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A stone-plastic composite material, characterized in that: The preparation comprises the following raw materials in parts by weight: 30-50 parts of inorganic filler, 50-70 parts of polymer, 0.5-4.5 parts of powder surface modifier, 0.01-1 parts of chain extender, 0.01-3 parts of modifier, and 1-3 parts of lubricant; The powder surface modifier includes at least two of a coupling agent, a ring-chain multipolymer hyperdispersant LD-1019, and a composite macromolecular polymer modifier LD-300P; the coupling agent includes a coupling agent containing a rare earth element, and the coupling agent containing a rare earth element is at least one of a rare earth coupling agent and a rare earth aluminum titanium composite coupling agent; The modifier comprises at least one of methyl methacrylate-butadiene-styrene terpolymer, polyolefin elastomer and glycidyl methacrylate; The chain extender includes at least one of an oxazoline chain extender and an isocyanate chain extender; The oxazoline chain extender includes at least one of 2,2-bis(2-oxazoline) and 2,2-(1,3-phenylene)-bis(2-oxazoline); The isocyanate chain extender includes at least one of diphenylmethane diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanate, and 1,5-naphthalene diisocyanate.

2. The stone-plastic composite material according to claim 1, wherein: The coupling agent further includes at least one of a titanate coupling agent, an aluminate coupling agent, a silane coupling agent, and an aluminum-zirconium composite coupling agent.

3. The stone-plastic composite material according to claim 1, wherein: Include at least one of the following: The lubricant includes at least one of a fatty acid lubricant, an amide lubricant, and a hydrocarbon lubricant; The polymer comprises at least one of high-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene, acrylonitrile-butadiene-styrene copolymer, polystyrene, polyethylene terephthalate, polycarbonate, nylon, polybutylene terephthalate, and polyoxymethylene; The particle size of the inorganic filler is 600-2500 mesh; The inorganic filler includes at least one of calcium carbonate, talc, diatomaceous earth, mica powder, kaolin and wollastonite.

4. A method for preparing the stone-plastic composite material according to any one of claims 1 to 3, characterized in that: The steps include: (1) Mixing the dried inorganic filler with a powder surface modifier to carry out a modification reaction to obtain a modified inorganic filler; (2) Adding a chain extender to carry out a chain extension reaction, and then adding a polymer, a modifier and a lubricant in sequence and blending them under stirring; (3) The blended materials are sequentially subjected to melt blending and extrusion granulation to obtain the stone-plastic composite material.

5. The method for preparing the stone-plastic composite material according to claim 4, wherein: Include at least one of the following: In step (1), the moisture content of the dried inorganic filler is ≤0.3%; In step (1), the temperature of the modification reaction is 70-135°C, and the time of the modification reaction is 1-60 minutes; In step (2), the temperature of the chain extension reaction is 70-135° C., and the time of the chain extension reaction is 1-60 minutes; In step (2), the blending temperature is 70-135° C., and the blending time is 1-60 minutes; In step (3), the temperature of the melt blending is 150-290°C, and the time of the melt blending is 15-60 minutes; In step (3), the temperature of the extrusion granulation is 130-295°C.

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