Multicolor wood-plastic profile and manufacturing method thereof and wood-plastic board

Abstract

A multi-color wood-plastic profile made of a color masterbatch and a wood-plastic base material, wherein the ratio λ of the tensile elastic modulus (Et) of the color masterbatch and the base material is 0.26-1.47. A manufacturing method of the multi-color wood-plastic profile includes mixing and melt-extruding the color masterbatch and the base material. A wood-plastic board including the multi-color wood-plastic profile. The multi-color wood-plastic profile has two or more colors on the outer surface and the inside, and presents a mixed gradient, natural wood-like texture.

Description

[0001] This application is a divisional application of the patent application with application number 202080100322.7, titled "A multi-color wood-plastic profile and its manufacturing method and wood-plastic board", and filed on April 30, 2020. TECHNICAL FIELD

[0002] The present application relates generally to wood-plastic composites. More specifically, the present application relates to multi-color wood-plastic profiles, in particular wood-plastic profiles based on polyolefins such as polyethylene or polypropylene, and to methods for their production and wood-plastic boards comprising them. BACKGROUND

[0003] Wood-plastic composites (WPC), also known as wood-plastic materials, combine the superior properties of wood and plastic and have been widely used in the field of construction. Depending on the use environment and production process, wood-plastic materials are divided into indoor decorative materials and outdoor building materials. Wood-plastic materials used indoors are usually made of polyvinyl chloride as raw material and are extruded into lightweight decorative building materials using weak mixing plasticizing equipment such as single-screw extruders. Wood-plastic materials used outdoors are usually made of polyethylene or polypropylene as raw material and are extruded into high-strength load-bearing building materials such as floorboards, fence boards, fence boards, wallboards, railings, staircases, benches, veranda supports, pavilions, etc. using strong mixing plasticizing equipment such as parallel twin-screw extruders or conical twin-screw extruders. Wood-plastic materials used outdoors have high mechanical strength, low water absorption, anti-aging, anti-mildew, and other characteristics to meet the requirements of the use environment. Polyvinyl chloride lightweight wood-plastic materials used indoors are less used in outdoor environments due to low strength, high water absorption, and other reasons, while polyolefin wood-plastic materials used outdoors can also be used indoors.

[0004] Currently, the wood-plastic production technology field mainly uses post-processing mechanical surface treatment methods or multi-color co-extrusion methods to manufacture wood-grain-imitating wood-plastic materials. In the post-processing mechanical surface treatment method, the plastic skin on the surface of the wood-plastic material product is removed by mechanical means such as sanding machines to reduce the plastic texture, and a hot press roller with patterns is used to roll on the surface of the product to form a wood-grain-imitating surface. The wood-grain-imitating wood-plastic material manufactured by the post-processing mechanical surface treatment method only has wood-grain-imitating texture on the surface, and the wood-grain-imitating texture formed by mechanical means tends to fade over time, and the surface layer and the inside of the wood-plastic material are of a single color, resulting in a monotonous visual effect. In the multi-color co-extrusion method, a surface layer extruder and a base layer extruder are used to extrude the surface layer raw material and the base layer raw material simultaneously into a specially designed co-extrusion die to form a wood-plastic profile with a better wood-grain-imitating texture on the surface. The multi-color co-extrusion method requires the addition of equipment and molds with higher investment costs, and the process is complex and costly.

[0005] With the development of building material market and wood-plastic product market, and more attention to environmental protection and resource comprehensive utilization, the demand for wood-plastic profiles with superior performance and beautiful appearance is more and more urgent. SUMMARY

[0006] In one aspect, the present application relates to a multi-color wood-plastic profile made of a color masterbatch and a base material, wherein the ratio λ of the tensile modulus of elasticity (Et) of the color masterbatch and the base material is 0.26-1.47. The tensile modulus of elasticity (Et) is used to characterize and compare the difference and size of the elasticity of the color masterbatch and / or the base material.

[0007] In another aspect, the present application relates to a color masterbatch and a method for manufacturing the same. The color masterbatch comprises or consists of about 30-60 parts by weight of polyethylene or polypropylene, about 20-50 parts by weight of a colorant, 0-30 parts by weight of a filler, and 0-5 parts by weight of an auxiliary selected from the group consisting of an antioxidant, a light stabilizer, a coupling agent, a lubricant, a dispersant and a compatibilizer, based on the total weight of the color masterbatch being 100 parts by weight. The color masterbatch is tested according to GB / T 1040.2-2006 / ISO 527-2:1993 standard, and the tensile modulus of elasticity (Et) is in the range of about 0.1x10 3 MPa to about 3x10 3 MPa.

[0008] In yet another aspect, the present application relates to a method for manufacturing the multi-color wood-plastic profile, which comprises mixing and melt-extruding the base material and the color masterbatch. The mixing and melt-extruding step can be carried out at the normal production process temperature of wood-plastic, without deliberately increasing the melt-extrusion temperature. The term "normal production process temperature of wood-plastic" (hereinafter can be referred to as normal process temperature) used herein refers to the melt-extrusion process temperature of conventional single-color wood-plastic profile in the art, which is generally 150℃ or lower. For example, according to one embodiment of the method for manufacturing the multi-color wood-plastic profile of the present application, the base material and the color masterbatch can be extruded at a temperature of about 145℃ or lower after being melted.

[0009] In yet another aspect, the present application relates to a wood-plastic board product comprising the multi-color wood-plastic profile, such as a wood-plastic floor board, a wood-plastic fence board, a wood-plastic rail board, a wood-plastic wall board, etc.

[0010] The present inventors have found that when the elasticity of the color masterbatch is within a certain specific range, for example, when the tensile modulus of elasticity (Et) of the color masterbatch is in the range of 3x10 3When the tensile elastic modulus of the color masterbatch is in the range of 0.26-1.47 times the tensile elastic modulus of the base material, the color masterbatch has a visible morphological change as a thermoplastic elastomer in the production of wood-plastic composite, which is caused by the shearing and tensile stress applied by the screw of the wood-plastic composite extruder in the hot melt state. The present inventors have further found that, when the tensile elastic modulus of the color masterbatch is in the range of 0.26-1.47 times the tensile elastic modulus of the base material, the morphological change of the color masterbatch in the melt state and the degree of integration of the color masterbatch and the base material can be adjusted by adjusting the tensile elastic modulus of the color masterbatch within a certain range, and the expected stripe morphology of the color masterbatch and the mixed color of the product can be obtained under the condition of the same base material. The melt morphological change and the degree of integration of the color masterbatch and the base material are also different when the same color masterbatch corresponds to base materials with different tensile elastic moduli. The present inventors have also found that, when the tensile elastic modulus of the color masterbatch exceeds the specific ratio range, for example, the tensile elastic modulus of the color masterbatch is too large or too small relative to the base material, the wood-plastic composite profile obtained presents a single color.

[0011] In the prior art, some use the difference in melting temperature and viscosity between the prepared color masterbatch and the wood-plastic base material to produce wood grain or flow lines at a temperature higher than the normal process temperature, such as 150-180°C or even higher. This technical solution not only increases energy consumption and cost, but also causes a certain degree of carbonization of wood powder and decomposition of plastic, reducing the quality of wood-plastic products. Some use the difference in melt flowability between the prepared color masterbatch and the wood-plastic base material to produce wood grain or flow lines by mixing and extruding the color masterbatch and the wood-plastic base material. In this type of technical solution, the amount of color masterbatch added is large, and the color masterbatch can account for 10-30% by weight of the mixture of color masterbatch and wood-plastic base material, and the production process temperature is also higher than the normal production process temperature of wood-plastic.

[0012] The wood grain or flow lines of the products in the prior art often exist on the outer surface of the wood-plastic product in the form of a skin, and have a smooth plastic texture. If the plastic skin is removed mechanically to enhance the wood texture, the effect of the wood grain or flow lines is destroyed and no longer exists.

[0013] Compared with the prior art, the preparation method of the multi-color wood-plastic profile of the present application has the following significant features: the multi-color wood-plastic profile can be produced at the normal production process temperature of wood-plastic, and the extrusion temperature can be below 150°C (for example, 130-150°C), which can control energy consumption and production cost and ensure product quality. The amount of color masterbatch added is extremely low, only 0.1-0.5% by weight of the mixture of color masterbatch and wood-plastic base material, and preferably 0.15-0.3% by weight. Compared with the prior art, in which the amount of color masterbatch added is 10-30% by weight of the mixture of color masterbatch and wood-plastic base material, the amount of color masterbatch is reduced by several tens or even hundreds of times under the same or better product effect, which is beneficial to reducing the production cost of the multi-color wood-plastic profile.

[0014] The technical effects achieved by the present application exceed the expectations and imagination of those skilled in the art.

[0015] The preparation method of the multi-color wood-plastic profile of the present application can easily obtain different stripe shapes of the color masterbatch, and mixed colors of different degrees of mutual fusion of the color masterbatch and the base material by selecting and adjusting the combination of the tensile elastic modulus of the color masterbatch and the base material, and can conveniently design and produce various product effects to meet different aesthetic habits and preferences of users.

[0016] The outer surface of the multi-color wood-plastic profile of the present application has two or more colors, each color exists independently or partially fuses between each color, and presents multi-color, mixed gradient and natural wood-like texture. The outer surface of the multi-color wood-plastic profile and any internal surface layer parallel to the outer surface both have natural wood color and texture, so that after surface treatment process such as polishing of the outer surface, the new surface still maintains the natural wood color and texture, which is an ideal wood-plastic product.

[0017] The preparation method of the multi-color wood-plastic profile of the present application has good compatibility with the existing single-color wood-plastic profile production process equipment, does not need to add high-cost equipment and molds, does not need to make any modification and adjustment to the production equipment and process, and is mature, reliable and easy to operate, so that the production cost is low.

[0018] The present application includes, for example, the following embodiments:

[0019] 1. A multi-color wood-plastic profile made of a color masterbatch and a base material, wherein the ratio λ of the tensile elastic modulus (Et) of the color masterbatch and the base material is 0.26-1.47.

[0020] 2. The multi-color wood-plastic profile according to embodiment 1, wherein the tensile elastic modulus (Et) of the color masterbatch is in the range of 0.1 x 10 3 MPa to 3 x 10 3 MPa, tested according to GB / T 1040.2-2006 / ISO 527-2:1993 standard.

[0021] 3. The multi-color wood-plastic profile according to embodiment 1, wherein the color masterbatch comprises a plastic and a colorant, and optionally an auxiliary agent selected from the group consisting of a filler, an antioxidant, a light stabilizer, a coupling agent, a lubricant, a dispersant, a compatibilizer; preferably the colorant is selected from the group consisting of carbon black and red iron oxide, yellow iron oxide, titanium white powder; preferably the filler is selected from light calcium.

[0022] 4. The multi-color wood-plastic profile according to any one of embodiments 1-3, wherein the content of the color masterbatch is 0.1 wt% to 0.5 wt%, preferably 0.15 wt% to 0.3 wt%, relative to the total weight of the color masterbatch and the base material.

[0023] 5. The multi-color wood plastic profile according to any one of embodiments 1-3, wherein the color masterbatch exists in rheological form selected from the group consisting of straight line, broken line, rod, ribbon, blob, ellipsoid and cloud shape, independently in the surface and any surface layer parallel to the surface of the wood plastic profile.

[0024] 6. The multi-color wood plastic profile according to any one of embodiments 1-3, wherein two or more colors exist in both the surface and any surface layer parallel to the surface of the wood plastic profile.

[0025] 7. The multi-color wood plastic profile according to any one of embodiments 1-3, wherein there are lines or spots in the same color as the color masterbatch in the cross section perpendicular to the surface of the wood plastic profile.

[0026] 8. The method of manufacturing the multi-color wood plastic profile according to any one of embodiments 1-7, comprising melt extruding the base material and the color masterbatch together.

[0027] 9. The method of manufacturing according to embodiment 8, further comprising, before melt extruding the base material and the color masterbatch together:

[0028] measuring the tensile elastic modulus of the base material;

[0029] selecting a suitable color masterbatch such that the ratio λ of the tensile elastic modulus (Et) of the color masterbatch and the base material is 0.26-1.47, according to the measured tensile elastic modulus of the base material.

[0030] 10. A wood plastic board comprising the multi-color wood plastic profile according to any one of embodiments 1-7 or manufactured by the method of manufacturing according to embodiments 8 or 9. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 Surface photo of the wood plastic profile obtained for Comparative Example 13.

[0032] Figure 2 Surface photo of the wood plastic profile obtained for Comparative Example 14.

[0033] Figure 3 Surface photo of the wood plastic profile obtained for Example 1.

[0034] Figure 4 Surface photo of the wood plastic profile obtained for Example 2.

[0035] Figure 5 Surface photo of the wood plastic profile obtained for Example 3.

[0036] Figure 6 Surface photo of the wood plastic profile obtained for Example 4

[0037] Figure 7 Cross-sectional view of the wood plastic profile obtained for Example 4.

[0038] Figure 8 Comparison of the surface of the wood plastic profile obtained for Example 5 before and after sanding treatment

[0039] Figure 9 Surface photograph of the wood plastic profile obtained for Example 6.

[0040] Figure 10 Surface photograph of the wood plastic profile obtained for Example 7.

[0041] Figure 11 Surface photograph of the wood plastic profile obtained for Example 8.

[0042] Figure 12 Surface photograph of the wood plastic profile obtained for Example 9.

[0043] Figure 13 Cross-sectional view of the wood plastic profile obtained for Example 9.

[0044] Figure 14 Surface photograph of the wood plastic profile obtained for Example 10.

[0045] Figure 15 Surface photograph of the wood plastic profile obtained for Example 11.

[0046] Figure 16 Surface photograph of the wood plastic profile obtained for Example 12. DETAILED DESCRIPTION

[0047] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. For example, reference to "a colorant" encompasses a single colorant as well as two or more colorants, and so forth.

[0048] As used herein, the terms "for example," "for instance," or "including" are intended to introduce examples that further clarify more general subject matter. These examples are not intended to limit the application that is described in the claims in any way.

[0049] Except in the Examples, or where otherwise explicitly indicated, all numerical quantities in the description and claims specified with the term "about" preceding the respective numerical value are to be construed as modifying that respective numerical value as though the term "about" were expressly recited immediately before the respective numerical value. It is intended that the phrase "about" as used herein applies similarly when it is recited near the beginning of a claim or immediately before a numerical value irrespective of whether the term "about" itself is expressly recited.

[0050] It should be understood that any numerical range recited herein includes all sub-ranges of the same numerical range. For instance, a range of from 1 to 10 also includes ranges of from 1 to 6, 4 to 8, 10 to 10, and so forth.

[0051] It should also be understood that any composition of the application described in the specification by any particular general or specific exemplifying part of the description is also described in an alternative respective definition in one embodiment for limiting any end point of the range described elsewhere in the specification for that composition, and can thus be used in one non-limiting embodiment in place of such range end point described elsewhere.

[0052] It should also be understood that any compound, material, or substance that is expressly disclosed or suggested in the specification, either explicitly or implicitly, as belonging to a group of structurally, compositionally and / or functionally related compounds, materials, or substances, including individual representatives of the group and all combinations thereof, is included within the scope of the present application.

[0053] The terms or words used in the present specification and claims should not be interpreted as being limited to generally used meanings or meanings in dictionaries, but should be interpreted based on the concepts of the present application in accordance with the following original meanings: the inventor can appropriately define the concepts of terms to explain the inventor's own application in the best way.

[0054] The term "multicolor" as used herein means that two or more colors are present, wherein each color can exist independently and / or each color can partially blend with each other to form a complex color. When "multicolor" is used in reference to a product, it means that at least the outer surface of the product exhibits two or more colors and each color can exist independently and / or each color can partially blend with each other. Further, for example, the outer surface of the product and at least a portion of the surface layer, preferably the entire surface layer, parallel to the outer surface, exhibits two or more colors. In one embodiment, each color, for example, a base color and a color master color, exists independently. In another embodiment, each color, for example, a base color and a color master color, partially blends with each other to form a complex color. In still another embodiment, each color, for example, a base color and a color master color, exhibits a complex color effect of two or more mixed gradations.

[0055] The term "wood plastic profile" as used herein refers to a wood plastic composite that is hot melt formed. Raw and auxiliary materials and forming methods of the wood plastic composite are well known in the art. Examples of the forming method include, but are not limited to, extrusion. The wood plastic material also includes a foaming agent added to make a lightweight wood plastic product having a lower density.

[0056] The term "base material" as used herein refers to a basic material that is present in a continuous phase in a molten state during the manufacturing process of the wood-plastic profile. The base material comprises a plastic (e.g., a thermoplastic resin) and a filler, and further optionally comprises a colorant and an auxiliary, including the addition of a blowing agent.

[0057] The term "color concentrate" as used herein refers to a colorant concentrate that is present in a dispersed phase in a molten state during the manufacturing process of the wood-plastic profile. The color concentrate comprises a plastic (e.g., a thermoplastic resin) and a colorant, and further optionally comprises an auxiliary.

[0058] In the present application, the tensile elastic modulus is tested at room temperature using a servo-controlled tensile testing machine or the like testing equipment according to the GB / T 1040.2-2006 / ISO 527-2:1993 standard. The tensile elastic modulus index is used to characterize or compare the elastic properties of the color concentrate and / or the base material.

[0059] In one aspect, the present application relates to a multi-colored wood-plastic profile made of a color concentrate and a base material, wherein the ratio λ of the tensile elastic modulus (Et) of the color concentrate to the tensile elastic modulus (Et) of the base material is from 0.26 to 1.47. When two or more color concentrates are used, the ratio λ (color concentrate : base material) of the tensile elastic modulus (Et) of each color concentrate to the tensile elastic modulus (Et) of the base material is from about 0.26 to about 1.47.

[0060] The color concentrate of the multi-colored wood-plastic profile according to the present application comprises a plastic and a colorant, and optionally a filler and an auxiliary. Examples of the auxiliary include, but are not limited to, an antioxidant, a light stabilizer, a coupling agent, a lubricant, a dispersant, and a compatibilizer. The auxiliary can be used alone or in combination. In one embodiment, the color concentrate of the multi-colored wood-plastic profile consists essentially of a plastic and a colorant. In another embodiment, the color concentrate of the multi-colored wood-plastic profile consists essentially of a plastic, a colorant, and a filler. Here, "consists essentially of" means that the weight percentage of the component is about 60% or more, in particular about 70% or more, more particularly about 80% or more, and in one embodiment about 90% or more or even about 95% or more.

[0061] The plastic used in the color masterbatch is not particularly limited, provided that the ratio λ of the tensile elastic modulus (Et) of the color masterbatch to that of the base material falls within the range of about 0.26 to about 1.47. In one embodiment, the plastic in the color masterbatch is a thermoplastic resin, particularly a polyolefin-based resin. Preferably, the polyolefin-based resin is polyethylene, polypropylene, or a combination thereof. Examples of the polyethylene include, but are not limited to, low-density polyethylene, high-density polyethylene, and a blend thereof. The polyethylene can include a modified polyethylene, such as a graft-modified or a blend-modified polyethylene, and the modifier can be at least one selected from conventional modifiers such as nylon 6, nylon 66, and the like. The polypropylene includes unmodified polypropylene and modified polypropylene, and the modified polypropylene includes a graft-modified polypropylene and a blend-modified polypropylene. In a preferred embodiment, the color masterbatch includes only one kind of polyethylene (e.g., one kind of low-density polyethylene or one kind of high-density polyethylene) or only one kind of polypropylene as the plastic component, which avoids a complicated process of blending two or more kinds of plastics (plastic alloys) for formulation and further reduces the manufacturing cost of the product.

[0062] The colorant used in the color masterbatch is not particularly limited and can be specifically selected depending on the coloring effect to be achieved, provided that the ratio λ of the tensile elastic modulus (Et) of the color masterbatch to that of the base material falls within the range of about 0.26 to about 1.47. The colorant includes an inorganic pigment and / or an organic pigment and / or a metallic pigment. Examples of the inorganic pigment include, but are not limited to, a mixture of one or more of titanium white, red iron oxide, yellow iron oxide, brown iron oxide, blue iron oxide, chromium oxide green, carbon black, and white carbon black. Examples of the metallic pigment include, but are not limited to, copper powder, bronze powder (copper-zinc alloy powder), silver powder (aluminum powder), and the like. Examples of the organic pigment include, but are not limited to, a mixture of one or more of azo pigments, heterocyclic pigments, and miscellaneous pigments. In one embodiment, the pigment is selected from carbon black and red iron oxide. In one embodiment, the content of the pigment is about 20 parts by weight to about 50 parts by weight, preferably about 20 parts by weight to about 40 parts by weight, based on 100 parts by weight of the total weight of the color masterbatch.

[0063] The filler used in the color masterbatch is not particularly limited, provided that the ratio λ of the tensile elastic modulus (Et) of the color masterbatch to that of the base material falls within the range of about 0.26 to about 1.47. The filler includes inorganic fillers and / or organic fillers. The organic fillers refer to fibrous materials derived from plants, examples of which include, but are not limited to, wood flour, sawdust, rice husks, bamboo powder, and a mixture of one or more of hemp. Examples of the inorganic fillers include, but are not limited to, light calcium (calcium carbonate), talc, silica, kaolin, mica, calcium silicate, glass fibers, and a mixture of one or more of fly ash. Preferably, the filler is an inorganic filler, particularly preferably light calcium. In one embodiment, the filler is used in an amount of 0 to about 35 parts by weight, for example, about 5 parts by weight to about 30 parts by weight, based on 100 parts by weight of the total weight of the color masterbatch. In the case where a filler, particularly an inorganic filler, is used, the total weight of the pigments and the filler is greater than about 35% by weight, preferably about 40% by weight or more, and preferably about 65% by weight or less, based on the total weight of the color masterbatch. When the total weight thereof is within this range, the ratio λ of the tensile elastic modulus (Et) of the color masterbatch to that of the base material can be easily adjusted to fall within the range of about 0.26 to about 1.47.

[0064] The antioxidants, light stabilizers, coupling agents, lubricants, dispersants, and compatibilizers used as the auxiliary agents in the color masterbatch are those commonly used in wood plastic composites. Examples of the antioxidants include, but are not limited to, phosphite-based and hindered phenol-based antioxidants. Examples of the light stabilizers include, but are not limited to, benzophenone-based and benzotriazole-based light stabilizers. Examples of the coupling agents include, but are not limited to, titanate-based and silane-based coupling agents. Examples of the lubricants include, but are not limited to, metal soaps, fatty acids and salts thereof, and fatty acid amide-based lubricants. Examples of the dispersants include, but are not limited to, fatty acid esters and fatty alcohol-based dispersants. Examples of the compatibilizers include, but are not limited to, maleic acid-modified polyolefin-based compatibilizers.

[0065] In one embodiment, the color masterbatch comprises or consists of about 30 to about 60 parts by weight of polyethylene or polypropylene, about 20 to about 50 parts by weight of a colorant, particularly an inorganic pigment or a metallic pigment, 0 to about 30 parts by weight of an inorganic filler, and 0 to about 5 parts by weight of an auxiliary selected from the group consisting of an antioxidant, a light stabilizer, a coupling agent, a lubricant, a dispersant, and a compatibilizer, based on the total weight of the color masterbatch being 100 parts by weight. Preferably, the total weight of polyethylene or polypropylene and the inorganic pigment or the metallic pigment is 60 parts by weight to 99.9 parts by weight, particularly about 70 parts by weight to about 98 parts by weight, more particularly about 75 parts by weight to about 97 parts by weight, of the total weight of the color masterbatch. Preferably, the total weight of the inorganic pigment or the metallic pigment and the inorganic filler is 30 parts by weight to 75 parts by weight, particularly about 35 parts by weight to about 70 parts by weight, more particularly about 40 parts by weight to about 65 parts by weight, of the color masterbatch. When the color masterbatch has a composition within the above ranges, the ratio λ of the tensile elastic modulus (Et) of the color masterbatch and the base material, particularly a base material based on recycled material such as polyethylene recycled material, can be easily adjusted to be within the range of about 0.26 to about 1.47, and the color masterbatch can be used in a low addition amount (e.g., 0.1% to 0.5% by weight, based on the total weight of the color masterbatch and the base material), thereby further reducing the production cost.

[0066] The base material of the multi-color wood plastic profile according to the present application comprises a plastic and a filler, and optionally further comprises a colorant and an auxiliary. Examples of the auxiliary include, but are not limited to, an antioxidant, a light stabilizer, a coupling agent, a lubricant, a dispersant, a compatibilizer, a flame retardant, a mildew-proof agent, and a foaming agent. The auxiliary can be used alone or in combination.

[0067] The plastic used in the base material is not particularly limited, as long as the ratio λ of the tensile elastic modulus (Et) of the color masterbatch and the base material falls within the range of about 0.26 to about 1.47. In one embodiment, the plastic in the base material is a thermoplastic resin, particularly a polyolefin-based resin. Preferably, the polyolefin-based resin is polyethylene, polypropylene, or a combination thereof. Examples of the polyethylene include, but are not limited to, low-density polyethylene, high-density polyethylene, and a blend thereof. The polyethylene can include recycled polyethylene. In one preferred embodiment, the base material uses only recycled polyethylene (e.g., recycled high-density polyethylene, recycled low-density polyethylene, or a mixture thereof) as the plastic component, which further reduces the manufacturing cost of the product. In one embodiment, the base material comprises about 20 to about 60 parts by weight of a polyolefin-based resin, particularly about 25 to about 50 parts by weight of the resin, more particularly about 25 to about 40 parts by weight of the resin, based on the total weight of the base material being 100 parts by weight.

[0068] The filler used in the base has no particular limitation, provided that the ratio λ of the tensile elastic modulus (Et) of the color concentrate to that of the base falls within the range of about 0.26 to about 1.47. The filler includes an organic filler and / or an inorganic filler. Examples of the organic filler include, but are not limited to, a mixture of one or more of wood flour, sawdust, rice husk, bamboo powder, hemp. Examples of the inorganic filler include, but are not limited to, a mixture of one or more of light calcium, talc, silica, kaolin, mica, calcium silicate, glass fiber, fly ash. In one embodiment, the filler is a blend of an organic filler and an inorganic filler. In a preferred embodiment, the blend of the organic filler and the inorganic filler is about 50% by weight or more, or about 60% by weight or more of the base. In a further preferred embodiment, the organic filler is about 40% by weight or more, or about 50% by weight or more of the base.

[0069] The colorant used in the base has no particular limitation and can be specifically selected depending on the coloring effect to be achieved and the colorant in the color concentrate. The colorant used in the base includes an inorganic pigment and / or an organic pigment. Examples of the inorganic pigment include, but are not limited to, a mixture of one or more of titanium dioxide, red iron oxide, yellow iron oxide, brown iron oxide, blue iron oxide, chromium oxide green, carbon black, white carbon black. The organic pigment includes a mixture of one or more of azo pigments, heterocyclic pigments, miscellaneous pigments. In one embodiment, the colorant is an inorganic pigment selected from the group consisting of titanium dioxide, red iron oxide, and yellow iron oxide. In one embodiment, the content of the colorant is about 10 parts by weight or less, or about 5 parts by weight or less, or even free of the colorant, based on 100 parts by weight of the total weight of the base. In a preferred embodiment, the content of the colorant is about 2 parts by weight to about 4 parts by weight.

[0070] The antioxidants, light stabilizers, coupling agents, lubricants, dispersants, compatibilizers, flame retardants, mildew-proofing agents, and blowing agents used as an aid in the base are those commonly used in wood plastic composites. Specific examples thereof include, but are not limited to, those described above for the color concentrate aid.

[0071] In an embodiment of the present application, the ratio λ of the tensile elastic modulus (Et) of the color masterbatch and the base material falls within a range of about 0.26 to about 1.47. The inventors of the present application have surprisingly found that by selecting and controlling the ratio of the tensile elastic modulus (Et) of the color masterbatch and the base material within a certain range of values, a multi-color wood-plastic profile having a good wood grain texture in the outer surface and in each surface layer parallel to the outer surface can be obtained. Through a large number of experimental comparisons, the inventors of the present application have found that, under the same conditions of the base material, equipment, process, etc., by selecting and replacing color masterbatches of different elastic sizes, i.e., color masterbatches of different tensile elastic modulus values, as the tensile elastic modulus value of the color masterbatch decreases, and as the ratio λ of the tensile elastic modulus (Et) gradually decreases within the above range, the melting rheological morphology of the color masterbatch in the base material changes from spots, to groups of spots, to broken lines, to rods, to wide stripes, to fine stripes, to a diffuse and scattered shape. When λ is equal to 1.68, the color masterbatch has a fine point shape, and the profile exhibits a single base material color, while when λ is equal to 0.20, the color masterbatch is completely melted, and the profile exhibits a single mixed color of the color masterbatch and the base material. In an embodiment, the ratio λ of the tensile elastic modulus (Et) of the color masterbatch and the base material falls within a range of about 0.70 to about 1.47, and in the obtained wood-plastic profile, the base material and the color masterbatch exist independently and exhibit their respective colors. In another embodiment, the ratio λ of the tensile elastic modulus (Et) of the color masterbatch and the base material falls within a range of about 0.26 to less than about 0.70, in particular about 0.69, more particularly about 0.68, or even more particularly about 0.67, so that in the obtained wood-plastic profile, the base material and the color masterbatch exist in an at least partially blended state, and thus the wood-plastic profile exhibits a complex color effect of a gradual blending of the base material and the color masterbatch colors.

[0072] In an embodiment, the color masterbatch has a tensile elastic modulus (Et) within a range of about 0.1 x 10 3 MPa to about 3 x 10 3 MPa, preferably within a range of about 0.2 x 10 3 MPa to about 3 x 10 3 MPa, preferably within a range of about 0.5 x 10 3 MPa to about 2.5 x 10 3 MPa, more particularly about 2.42 x 10 3 MPa, about 2.11 x 10 3 MPa, about 1.92 x 10 3 MPa, about 1.80 x 10 3 MPa, about 1.66 x 10 3 MPa, about 1.55 x 10 3about 1.45 x 10 3 about 1.24 x 10 3 about 1.12 x 10 3 about 0.86 x 10 3 about 0.86 x 10

[0073] In one preferred embodiment, the color masterbatch melt morphology in the base material is clear, typical elongated streaks, and after sanding, the interior parallel to any plane of the surface layer has the same clear elongated streaks as the surface layer. The surface of the profile is primarily two colors, the base color of the base material and the black streaks, with a small amount of a mixture of the two colors. In another preferred embodiment, the base material is the same and a different color masterbatch is selected, and the color masterbatch melt morphology in the base material is wider streaks, and in a cross-section perpendicular to the surface of the wood plastic profile, there are lines or spots of the same color as the color masterbatch. In another preferred embodiment, the color masterbatch melt morphology in the base material is clear rods, and the surface of the profile is only two colors, the base color of the base material and the black streaks. In another preferred embodiment, the color masterbatch melt is diffuse clouding, and the surface of the profile has the base color of the base material, the black color of the color masterbatch, and a mixture of different shades of the colors that gradually change.

[0074] In yet another embodiment, by using two or more color masterbatches each having a ratio λ of the tensile elastic modulus (Et) of the base material of about 0.26 to about 1.47, the resulting wood plastic profile has streaks of each color masterbatch in the outer surface of the profile and in each surface layer parallel to the outer surface. In one example, the base material is white, and the color masterbatches include a black color masterbatch and a brown color masterbatch, and the resulting wood plastic profile has black and brown streaks on the surface.

[0075] In another aspect, the present application relates to a method of manufacturing a multi-colored wood plastic profile, which includes mixing and melt-extruding the base material and the color masterbatch. In one embodiment, before mixing and melt-extruding the base material and the color masterbatch, the method can further include measuring the tensile elastic modulus of the base material, and selecting a suitable color masterbatch based on the measured tensile elastic modulus of the base material, such that the ratio λ of the tensile elastic modulus (Et) of the color masterbatch and the base material is 0.26 to 1.47. The method of manufacturing a multi-colored wood plastic profile according to the present application allows for the selection of a suitable color masterbatch for a low-cost base material according to the desired streaks of the wood plastic profile of different users, so that a wide variety of product effects can be conveniently designed and produced to meet the different aesthetic habits and preferences of users.

[0076] The wood plastic profile obtained by mixing and melt-extruding can optionally undergo one or more of the following operations: cooling, cutting, and surface treatment. Examples of the surface treatment include, but are not limited to, sanding, wire drawing, embossing, and surface treatment with a surface treatment agent such as a finish, etc.

[0077] The base material and the color masterbatch can be mixed before the melt extrusion operation or during the melt extrusion operation. In one embodiment, the manufacturing method can include feeding a predetermined ratio of the color masterbatch and the base material into an extruder after being uniformly stirred by a stirrer, and then continuously melt extruding through the extruder to form the multi-color wood plastic profile. In another embodiment, the manufacturing method includes feeding the base material and the color masterbatch separately into the extruder synchronously and separately, mixing by shearing stirring of the extruder screw, and then continuously melt extruding through the extruder to form the multi-color wood plastic profile. In this embodiment, the ratio of the color masterbatch to the base material can be adjusted by the rotation speed of the feeding mechanism. The extruder can be a conventional extruder commonly used in processing thermoplastic resins. Examples of the extruder include, but are not limited to, a single screw extruder, a twin screw extruder, and a multi screw extruder. The temperature in each barrel (zone) of the extruder and the rotation speed of the screw can be appropriately determined depending on the material to be extruded. The multi-color wood plastic profile manufacturing method according to the present application can allow the temperature in each barrel (zone) of the extruder to be below 150°C, for example, the temperature of the merging core and the die in the plasticizing extrusion barrel (zone) can be controlled to be even below 145°C. The production of the multi-color wood plastic profile is performed at such normal production process temperature of wood plastic, so that the product quality is stable and the energy cost is low.

[0078] The color masterbatch and the base material can be manufactured using methods known in the art. For example, the color masterbatch can be prepared by adding the plastic, the pigment, and the optional additive in a predetermined ratio into a high speed mixer, uniformly mixing, melt extruding the resulting mixture using an extruder such as a twin screw extruder, and cooling, pelletizing, centrifugal dewatering, and air drying.

[0079] In still another aspect, the present application relates to a product including the multi-color wood plastic profile, for example, a deck, a railing, a stair, a bench, a veranda, a gazebo, etc. Preferably, the product is a wood plastic board such as a wood plastic floor, a wood plastic fence board, a wood plastic wall board, etc.

[0080] Examples

[0081] The present application will be explained more specifically with reference to examples, but these examples should not be construed as limiting the scope of the present application. Also, in the following description, unless otherwise specified, "parts" means "parts by weight" and "%" means "wt%".

[0082] The materials used in each example are listed in Table 1 below.

[0083] Table 1: Summary of Material Information

[0084]

[0085] Preparation Example of Color Masterbatch

[0086] The plastic, pigment, and additives shown in Table 2 were added into a high-speed mixer SHR-300A in the weight percentages shown, and stirred at a speed of 1480 rpm for 10 minutes. The resulting mixture was added into a parallel twin-screw extruder AK-73 (Nanjing KaoYa Chemical Equipment Co., Ltd.), and after melt extrusion and granulation, each color masterbatch was obtained: Nos. H1-1 to H3-1 were black color masterbatches, and Nos. Z1-1 and Z1-2 were brown color masterbatches. The melt extrusion conditions were as follows: screw length-diameter ratio L / D = 44, screw rotation speed 600 rpm, extruder temperature settings for zones 1-11 were 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 170°C, 180°C, and 190°C, respectively, and the melt temperature was 190°C.

[0087] The tensile elastic modulus of each color masterbatch was measured using a servo-controlled tensile testing machine AI-7000-M1 (Gao Tie Testing Instrument (Dongguan) Co., Ltd.), and the results are shown in Table 2.

[0088] Preparation of base materials

[0089] The PE recyclate, pigment, and additives shown in Table 3 were added into a high-speed mixer SHR-300A in the weight percentages shown, and stirred at a speed of 1480 rpm for 10 minutes. The resulting mixture was added into a parallel twin-screw extruder AK-73 (Nanjing KaoYa Chemical Equipment Co., Ltd.), and after melt extrusion and granulation, each base material was obtained. The melt extrusion conditions were as follows: screw length-diameter ratio L / D = 44, screw rotation speed 600 rpm, extruder temperature settings for zones 1-11 were 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 170°C, 180°C, and 190°C, respectively, and the melt temperature was 190°C.

[0090] The tensile elastic modulus of each color masterbatch was measured using a servo-controlled tensile testing machine AI-7000-M1 (Gao Tie Testing Instrument (Dongguan) Co., Ltd.), and the results are shown in Table 3.

[0091]

[0092]

[0093] Examples 1-12 and Comparative Examples 13-14

[0094] The base material of each example and comparative example except for Example 9 and the color masterbatch were added into a counter-rotating conical twin-screw extruder SJZ65 / 132 (Shanghai Jinwei Machinery Manufacturing Co., Ltd.) according to the combination and amount shown in Table 4 to obtain wood-plastic profiles by melt extrusion. The melt extrusion conditions were as follows: screw rotation speed 34.7 rpm; extruder temperature: 150°C for zone 1, 150°C for zone 2, 140°C for zone 3, 140°C for zone 4, and 140°C for the converging core; and mold temperature: 140°C, 140°C, 140°C, and 140°C. The ratio λ of the tensile elastic modulus of the color masterbatch to the wood-plastic profile is also shown in Table 4. The color masterbatch was added in the following proportions: 0.5% for Example 1, 0.5% for Example 2, 0.1% for Example 3, 0.25% for Examples 4 to 7 and 9, 0.3% for Examples 8 and 10, 0.3% for the brown color masterbatch and 0.1% for the black color masterbatch for Example 11, 0.25% for Example 12, 0.25% for Comparative Example 13, and 0.25% for Comparative Example 14.

[0095] In addition, Example 9 differs in that a co-extrusion method using two extruders working simultaneously was used. In this Example 9, a core layer material including the following formulation was extruded into a wood-plastic profile using a counter-rotating conical twin-screw extruder SJZ65 / 132 at the same conditions as described above: PE recycled material 25%, wood powder 60%, light calcium 10%, composite lubricant 2%, compatibilizer 2.5%, and auxiliary antioxidant 0.5%. At the same time, the color masterbatch and base material of Example 9 shown in Table 4 were mixed as a surface layer material, and a co-extruded surface layer was formed on the surface of the core layer material using a single-screw extruder SJ20 at a screw rotation speed of 20 rpm. The temperature of the co-extrusion mold (Huangshi Gaokeli Plastic Mold Co., Ltd.) was 140°C, 140°C, 140°C, and 140°C.

[0096] Subsequently, the surface of the extruded products obtained in all examples and comparative examples was subjected to mechanical surface treatment by removing the surface plastic skin. In addition, the surface of the products obtained in Example 1, Example 3, Example 7, Example 8, Comparative Example 13, and Comparative Example 14 was further subjected to hot-press mechanical treatment.

[0097] Table 4 Formulation of wood-plastic profiles and ratio (λ) of tensile elastic modulus Et of color masterbatch and base material

[0098]

[0099] The color and pattern of the outer surface of each wood-plastic profile obtained were observed. Note that: Figure 1 (Comparative Example 13), Figure 2 (Comparative Example 14), Figure 3 (Example 1), Figure 5 (Example 3), Figure 10 (Example 7), Figure 11The through-long stripes shown in the surface photos of (Example 8) were obtained using a subsequent mechanical treatment with a hot embossing roller. It was found that Comparative Example 13 (λ = 1.68) presented a single white wood-plastic base color, and the pattern shown was a regular pattern obtained by subsequent mechanical treatment with a hot embossing roller (see Figure 1 ); while Comparative Example 14 (λ = 0.20) presented a single brown color masterbatch base color, and the pattern shown was a regular pattern obtained by subsequent mechanical treatment with a hot embossing roller (see Figure 2 ). In contrast, in the examples of the present application, as the ratio of the tensile elastic modulus decreased from 1.47 to 0.26, the color masterbatch melt rheological pattern changed from blob- to zigzag- to rod- to wide-short stripe- to elongated stripe- to diffuse cloud shape, as shown in Figures 3-16 . Figures 3-16 The surface photos of the wood-plastic profiles obtained in Example 1 (λ = 1.47), Example 2 (λ = 1.33), Example 3 (λ = 0.70), Example 4 (λ = 0.63), Example 5 (λ = 0.58), Example 6 (λ = 0.51), Example 7 (λ = 0.44), Example 8 (λ = 0.67), Example 9 (λ = 0.45), Example 10 (λ = 0.26), Example 11 (λ = 0.37 and λ = 0.48), and Example 12 (λ = 0.29) are shown, respectively. The melt pattern of the color masterbatch in the base material presented small blobs in Example 1 (see Figure 3 , as shown in the oval box), a zigzag shape in Example 2 (see Figure 4 , as shown in the oval box), large blobs and rod-shaped stripes in Examples 3 and 8, respectively (see Figure 5 and Figure 11 , as shown in the oval box), wide-short and elongated stripe shapes in Examples 4 and 5, respectively (see Figure 6 and Figure 8 , as shown in the oval box), and diffuse cloud shapes in different degrees in Examples 6, 7, 9, 10, 11, and 12 (see Figure 9 , Figure 10 , Figure 12 , Figure 14 , Figure 15 and Figure 16 , as shown in the oval box). The changes in the shapes of the blobs, zigzag, rod, wide-short stripe, elongated stripe, and diffuse cloud refer to other color patterns besides the through-long stripes and light base color obtained by mechanical hot roller pressing.

[0100] Furthermore, as shown in Figure 5 , in the wood-plastic profile obtained in Example 3, the white (base material) and black (color masterbatch) colors existed independently, and there were only two colors, white and black, on the surface of the profile. As shown in Figure 8As shown, in the wood-plastic profile obtained in Example 5, the red (base material) and black (masterbatch) portions blend to present different shades of reddish-brown as its secondary color, resulting in a wood-plastic profile surface with red, black, and different shades of reddish-brown. Thus, the masterbatch color and base material color present a mixed gradient effect of two or more colors. Similarly, as... Figure 6 As shown, in the wood-plastic composite profile obtained in Example 4, red, black, and brown also exhibit a mixed gradient polychrome effect. This indicates that in the wood-plastic composite profile of the present invention, because the color masterbatch exists in different states in the base material—non-fusible, partially fusible, and completely fusible—the color masterbatch and base material colors can exhibit two or more mixed gradient polychrome effects. In practical applications, different combinations of color masterbatches and base materials can be selected according to the desired pattern to achieve the ideal appearance effect.

[0101] Figure 8 This is a comparison image of the wood-plastic composite profile obtained in Example 5 before and after surface treatment. The right side is a photo of the internal layers after the surface layer of the product was scraped off with a sander. In the experiment, after scraping off several layers, different colors and melt flow patterns of color masterbatch were also visible on any surface of the product.

[0102] Figure 7 This is a cross-sectional view of Example 4 and Figure 13 This is a cross-sectional view of Example 9. As can be seen from the figure, lines or spots of the same color as the color masterbatch exist on the cross-section perpendicular to the surface of the wood-plastic profile. Furthermore, as... Figure 13 As shown in the co-extruded top layer (white part), the co-extruded top layer material melt rheology production process follows the same mechanism and control method.

[0103] Furthermore, the melt extrusion equipment and temperatures used in the above embodiments are those commonly used in the manufacture of ordinary non-multicolored wood-plastic profiles. This indicates that the multicolored wood-plastic profile preparation method of the present invention is highly compatible with existing wood-plastic profile production processes and equipment. It does not require additional high-cost equipment and molds, nor does it require any modification or adjustment to the production equipment and processes. The process is mature, reliable, and easy to operate, resulting in lower production costs. Moreover, the same temperature and extruder screw speed ensure the production efficiency and product quality of the wood-plastic profile extrusion production.

[0104] Mechanical performance evaluation

[0105] The wood-plastic profiles obtained in Examples 1-12 were subjected to a falling weight impact test according to EN 15534-1 :2014 Section 7.1.2.1, a bending resistance test according to EN 15534-1 :2014 Annex A, a boiling test according to EN 15534-1 :2014 Section 8.3.3, a linear thermal expansion coefficient test according to EN 15534-1 :2014 Section 9.2, a creep behavior test according to EN 15534-1 :2014 Section 7.4.1, and a water absorption expansion test according to EN 15534-1 :2014 Section 8.3.1, all of which were passed.

[0106] While the application has been described with reference to specific embodiments, it will be apparent to those skilled in the art that various changes can be made and equivalents can be substituted for elements thereof without departing from the scope of the application. The application is not to be limited only to the expressly disclosed embodiments. Rather, it is intended and to include all embodiments falling within the scope of the appended claims.

Claims

1. A multi-colored wood-plastic profile, comprising a color masterbatch and a base material, wherein the ratio λ of the tensile modulus (Et) of the color masterbatch and the base material is 0.26-1.

47. The color masterbatch contains plastic and colorant. The base material comprises plastic and fillers. In the wood-plastic profile, on the surface and in any layer parallel to the surface, the color masterbatch exists independently in a rheological form selected from the following: linear, zigzag, rod-shaped, band-shaped, patch-shaped, ellipsoidal, and cloud-shaped. The tensile modulus (Et) of the color masterbatch is 1.12 x 10⁻⁶. 3 MPa up to 2.11x10 3 Within the range of MPa; The tensile modulus (Et) of both the color masterbatch and the base material was tested in accordance with GB / T 1040.2-2006 / ISO 527-2:1993 standard; The plastic in the color masterbatch includes polyethylene, polypropylene, or a combination thereof; The plastic in the base material includes polyethylene, polypropylene, or combinations thereof; and The content of the color masterbatch is 0.1% to 0.5% by weight relative to the total weight of the color masterbatch and the base material.

2. The multi-colored wood-plastic profile according to claim 1, wherein the color masterbatch further comprises additives selected from the following: fillers, antioxidants, light stabilizers, coupling agents, lubricants, dispersants, and compatibilizers.

3. The multi-colored wood-plastic profile according to claim 1, wherein the colorant is selected from carbon black, iron oxide red, iron oxide yellow and titanium dioxide.

4. The multi-colored wood-plastic profile according to claim 2, wherein the filler contained in the color masterbatch is selected from light calcium carbonate.

5. The multi-colored wood-plastic profile according to any one of claims 1-4, wherein the content of the color masterbatch is 0.15%-0.3% by weight relative to the total weight of the color masterbatch and the base material.

6. The multi-colored wood-plastic profile according to any one of claims 1-4, wherein the filler in the base material comprises organic fillers and / or inorganic fillers.

7. The multi-colored wood-plastic profile according to claim 6, wherein the organic filler is selected from one or a mixture of several of wood flour, sawdust, rice husk, bamboo powder, and hemp.

8. The multi-colored wood-plastic profile according to claim 6, wherein the inorganic filler is selected from one or a mixture of several of light calcium carbonate, talc, silica, kaolin, mica, calcium silicate, glass fiber, and fly ash.

9. The multi-colored wood-plastic profile according to any one of claims 1-4, wherein the base material further comprises a colorant and an additive selected from the group consisting of antioxidants, light stabilizers, coupling agents, lubricants, dispersants, compatibilizers, flame retardants, mildew inhibitors, and foaming agents.

10. The multi-colored wood-plastic profile according to any one of claims 1-4, wherein two or more colors are present on the surface of the wood-plastic profile and in any layer parallel to the surface.

11. The multi-colored wood-plastic profile according to any one of claims 1-4, wherein lines or spots of the same color as the color masterbatch exist on a cross section perpendicular to the surface of the wood-plastic profile.

12. A method for manufacturing multi-colored wood-plastic profiles according to any one of claims 1-11, comprising mixing and melting the base material and the color masterbatch and then extruding the mixture.

13. The manufacturing method according to claim 12, further comprising, prior to the melt extrusion of the base material and the color masterbatch: Measure the tensile modulus of elasticity of the base material; Based on the measured tensile modulus of elasticity of the base material, select a suitable color masterbatch such that the ratio λ of the tensile modulus of elasticity (Et) of the color masterbatch and the base material is 0.26-1.

47.

14. A wood-plastic composite board comprising the multi-colored wood-plastic profile as described in any one of claims 1-11 or the multi-colored wood-plastic profile produced by the manufacturing method of claim 12 or 13.

Images