KR102548429B1 - Plumbing HDPE plastic compound compositions and method for manufacturing the compound compositions - Google Patents

Abstract

A high-density polyethylene (HDPE) plastic compound composition for piping and a manufacturing method thereof are disclosed. The HDPE plastic compound composition according to one embodiment includes a high-density polyethylene resin, ceramic microspheres (CM) having a diameter of 1 to 20 μm, and an additive, and with respect to the high-density polyethylene resin, the ceramic microspheres are 10 to 30 % by weight and the additives are included in an amount of 0.5 to 0.7% by weight, and the additives are chemically bonded to the ceramic microspheres and an adhesive having physical adhesion to each between the ceramic microspheres and the high-density polyethylene resin, It includes at least one coupling agent that physically adheres to the high-density polyethylene resin.

Description

HDPE plastic compound composition for plumbing and method for manufacturing the same {Plumbing HDPE plastic compound compositions and method for manufacturing the compound compositions}

The present invention relates to a manufacturing technology of a plastic compound, and more particularly, to a manufacturing technology of a high density polyethylene (HDPE) plastic compound used for extrusion manufacturing of a pipe.

Plastic refers to organic-based polymer materials and mixtures thereof that can be molded by heat or pressure, and is also referred to as a synthetic resin. Plastics are used for a variety of purposes ranging from films, synthetic fibers, bottles, tubes, and toys that we widely use in our daily lives to highly heat-resistant and high-strength materials. , crystalline/amorphous plastics, etc.

Although plastic is used as such, it is common to use it in the form of a plastic compound for the purpose of improving properties, improving moldability, and reducing costs. Plastic compounds make plastics more useful than polymers themselves, so that they can be applied to the manufacturing process of various products. It refers to mixing with various other sub-materials (fillers). In order to manufacture a desired product by injection or extrusion, a plastic compound is usually molded into a specific shape, for example, pellets such as rice grains. can be used to prepare

Materials that form a separate phase in a plastic compound and are used in significant amounts to replace plastic resins are called fillers or fillers. Fillers can be largely classified into fiber type and particulate type, and in the case of particulate type, inorganic conductive filler, organic filler, and mineral filler are used. can be distinguished. Talc is a representative material among mineral fillers, and in addition, there are calcium carbonate (CaCO ₃ ), red mud, and the like.

These fillers are used for the purpose of imparting and/or reinforcing various properties to plastic raw materials, such as improving heat resistance, increasing rigidity, reducing shrinkage, and modifying flow. In addition, by using a relatively inexpensive material as a filler, it is possible to lower the unit cost of the plastic compound in addition to maintaining or improving desired properties in the plastic. However, since these by-products are non-uniform in composition, size, particle shape, etc., it is difficult to use them as fillers for plastic compounds that can satisfy desired properties by themselves.

Meanwhile, various plastic compounds may be used to manufacture piping used to transport water, gas, and other fluids, one of which is high-density polyethylene (HDPE). Like other plastic compounds for piping, HDPE compounds for piping must meet specific criteria such as formability, stiffness, resistance to slow rate growth, and chemical non-reactivity. For example, Korean Patent Publication No. 2007-0020053, "HDPE resin for use in pressure pipes and related applications" (Patent Document 1) discloses a HDPE resin composition suitable for PE-100 pipes. And Korean Patent Publication No. 2007-0034046, "Polyethylene pipe resin" (Patent Document 2) has a fluidity index (MI ₅ ) of 0.70g / 10 minutes, 47 to 52% by weight of LDPE and 48 to 53% by weight of HDPE It discloses a polyethylene resin composition comprising a. However, these Patent Documents 1 and 2 do not disclose fillers used to reduce the manufacturing cost while maintaining or improving the physical properties of the HDPE resin composition for pipes.

Korean Patent Publication No. 2007-0020053 Korean Patent Publication No. 2007-0034046

One problem to be solved by the present invention is to provide an HDPE plastic compound composition and a method for manufacturing the same, which can reduce manufacturing costs while satisfying various physical properties required for pipes such as water pipes.

One embodiment of the present invention for solving the above problems is a high-density polyethylene (HDPE) plastic compound composition for piping, comprising a high-density polyethylene resin, ceramic microspheres (CM) having a diameter of 1 to 20 μm and additives, , With respect to the high-density polyethylene resin, the ceramic microspheres and the additives are included in 10 to 30% by weight and 0.5 to 0.7% by weight, and the additives are physically located between the ceramic microspheres and the high-density polyethylene resin, respectively. It includes at least one of an adhesive having adhesiveness and a coupling agent that chemically binds to the ceramic microspheres and physically adheres to the high-density polyethylene resin.

According to one aspect of the embodiment, the adhesive may include a maleic anhydride-based compound, and the coupling agent may include a silane-based compound.

Here, the maleic anhydride-based compound includes modified maleic anhydride grafted polypropylene, and the silane-based compound includes vinyltrimethoxysilane, r-aminopropyltrimethoxysilane, r-mercaptopropyltrimethoxysilane, N-(B-aminoethyl) -r-aminopropyltrimethoxysilane, n-octyltriethoxysilane, hexadecyltrimethoxysilane, and alkyltrimethoxysilane (here, alkyl may include one or more compounds selected from the group consisting of 2 to 8 C).

Another embodiment of the present invention for solving the above problems is a method for manufacturing a high-density polyethylene (HDPE) plastic compound for piping, using a high-density polyethylene resin, ceramic microspheres (CM) having a diameter of 1 to 20 μm, and additives Injecting into an extruder and kneading the high-density polyethylene resin, the ceramic microspheres, and the additive at a temperature of 200 to 210 ° C. in the extruder, wherein, for the high-density polyethylene resin, the ceramic microspheres are 10 ~ 30% by weight and 0.5 ~ 0.7% by weight of the additives, wherein the additives are physically bonded to each other between the ceramic microspheres and the high-density polyethylene resin, and chemically bonded to the ceramic microspheres. and may include one or more coupling agents that physically adhere to the high-density polyethylene resin.

According to one aspect of the embodiment, the adhesive includes modified maleic anhydride grafted polypropylene, and the coupling agent is vinyltrimethoxysilane, r-aminopropyltrimethoxysilane, r-mercaptopropyltrimethoxysilane, N-(B-aminoethyl)- It may include one or more compounds selected from the group consisting of r-aminopropyltrimethoxysilane, n-octyltriethoxysilane, hexadecyltrimethoxysilane, and alkyltrimethoxysilane (here, alkyl has a C of 2 to 8).

According to the above-described embodiment of the present invention, by using ceramic microspheres as a filler for HDPE resin and by appropriately selecting and using additives that improve the compatibility of the two materials, In addition to satisfying various physical properties, it is possible to lower the manufacturing cost.

1A is a view schematically showing a process of improving compatibility between ceramic microspheres (CM) and HDPE resin when an adhesive is used as an additive.
Figure 1b is a view schematically showing a process of improving compatibility between ceramic microspheres (CM) and HDPE resin when a coupling agent is used as an additive.
2 is a diagram schematically showing a reaction mechanism occurring on the surface of ceramic microspheres (fillers) when a silane-based compound is used as a coupling agent.
Figure 3 is a flow chart showing a manufacturing method of the HDPE plastic compound for piping according to an embodiment of the present invention.
4 is a cross-sectional view schematically showing the configuration of an extruder.
5 is a graph showing the experimental results of Table 5.
6 is a graph showing the experimental results of Tables 7 and 8.
FIG. 7 separately shows only the TE results in FIG. 6 .

Hereinafter, preferred embodiments and examples of the present invention will be described with reference to the drawings. However, the following embodiments and examples are merely illustrative of preferred configurations of the present invention, and the scope of the present invention is not limited to these configurations. And in the following description, the hardware configuration and software configuration of the device, processing flow, manufacturing conditions, size, material, shape, etc. are not intended to limit the scope of the present invention to these unless specifically described. .

High-density polyethylene (HDPE) plastic compound composition for piping according to an embodiment of the present invention uses HDPE resin as a base material and is selected from coal ash (or coal ash), which is a waste product after using coal as fuel in a thermal power plant. ceramic microspheres (CM) as a filler. According to this, since some of the selected coal ash is used as a filler, the cost of the HDPE plastic compound can be significantly reduced. In addition, since it utilizes industrial waste, it also helps to protect the environment.

According to an embodiment of the present invention, ceramic microspheres are 'spherical fine particles' selected from coal ash, and in particular, refer to spherical particles having a diameter of 20 μm or less, for example, 1 to 20 μm, among fly ash . Therefore, among coal ash, bottom ash or fly ash, relatively large particles (eg, greater than 20 μm in diameter) or needle-shaped or plate-shaped particles occupying a significant proportion of coal ash are not included in the ceramic microspheres. don't Ceramic microspheres are mainly composed of silicon oxide (SiO ₂ ), and the average composition is shown in Table 1.

These ceramic microspheres are selected from coal ash, but there is no particular limitation on a specific method for screening them. For example, as long as particles are classified according to shape and/or size from a raw material in which particles of various sizes and shapes are mixed, the method is not particularly limited. In one example, ceramic microspheres may be screened from coal ash by using one or more filters having apertures of a particular shape and size.

As such, in the embodiment of the present invention, only very fine and spherical particles among coal ash are used as fillers. Therefore, the HDPE plastic compound according to an embodiment of the present invention has overall uniform physical properties, and by appropriately adjusting the amount of the filler, the physical properties such as impact strength and abrasion resistance can be adjusted to be higher than the evaluation criteria required for the pipe. In particular, since ceramic microspheres have a spherical shape rather than a needle or plate shape, when a product is manufactured using an injection molding machine or an extruder using a plastic compound including the ceramic microspheres, processability can be improved due to increased flowability.

In general, inorganic fillers in plastic compounds may have poor compatibility with organic plastic resins, resulting in a decrease in physical properties or little change in physical properties. As a result of the experiment, as shown in Table 2, even if the ceramic microspheres are not mixed with the plastic resin (eg, polypropylene) or 10% by weight and 20% by weight are added, respectively, the melt flow index (MI), There is no clear increase in impact strength (IZOD) and flexural modulus (FM), and tensile properties such as tensile strength (TS) or tensile elongation (IE) or bending strength ( It was also confirmed that trends such as Flexural Strength (FS) or Heat Deflection Temperature (HDT) were not clear.

In order to prevent a decrease in physical properties and obtain desired physical properties, it is necessary to improve the compatibility between the organic HDPE resin and the inorganic ceramic microspheres. To this end, the HDPE plastic compound composition for piping according to an embodiment of the present invention further includes an additive for improving compatibility between the HDPE resin and the ceramic microspheres.

According to an embodiment of the present invention, the additive includes at least one of an adhesive and a coupling agent. Here, the adhesive refers to a compound having physical adhesion between the ceramic microsphere and the HDPE plastic resin, and the coupling agent chemically bonds with the inorganic ceramic microsphere and has physical adhesion with the HDPE plastic resin. refers to compounds. Preferably, the additive may include both an adhesive and a coupling agent.

1a is a view schematically showing a process of improving the compatibility between ceramic microspheres (CM) and HDPE resin when an adhesive is used as an additive. (represented by three curves) induces physical adhesion between them. And Figure 1b is a view schematically showing a process of improving compatibility between ceramic microspheres (CM) and HDPE resin when a coupling agent is used as an additive, wherein one end of the coupling agent is It is chemically bonded, and the other end is physically bonded to the HDPE resin.

According to this embodiment of the present invention, it is preferable that the additives included in the HDPE plastic compound do not include a crosslinking agent that is chemically bonded to the ceramic microspheres and the HDPE resin, respectively. This is because, when a crosslinking agent is used, compatibility with ceramic microspheres may be improved, but it may act as a crosslinking agent for plastics, resulting in adverse effects on injection or extrusion processing, that is, deterioration in moldability.

The adhesive preferably contains a maleic anhydride-based compound. For example, the maleic anhydride-based adhesive may be a modified maleic anhydride grafted polypropylene. The modified maleic anhydride polypropylene is made of non-polar polypropylene at one end, so it has excellent affinity with the also non-polar HDPE resin, and the other end is grafted with maleic anhydride, so it has good adhesion with ceramic microspheres. easy to do

The coupling agent preferably includes a silane-based compound. For example, silane-based coupling agents include vinyltrimethoxysilane, r-aminopropyltrimethoxysilane, r-mercaptopropyltrimethoxysilane, N-(B-aminoethyl)-r-aminopropyltrimethoxysilane, n-octyltriethoxysilane, hexadecyltrimethoxysilane and alkyltrimethoxysilane (where C is 2 to 16, Preferably, C may include one or more compounds selected from the group consisting of 2 to 8).

2 is a view schematically showing a reaction mechanism occurring on the surface of ceramic microspheres (fillers) when a silane-based compound is used as a coupling agent. In FIG. 2, the left side is a schematic diagram of the ceramic microspheres (filler) before using the coupling agent (before treatment), and the right side is a schematic diagram of the ceramic microsphere (filler) surface treated using the coupling agent (after treatment). It is also a model for As shown in FIG. 2, one end of the silane-based compound is composed of a non-polar group to improve chemical intimacy with the HDPE resin (organic functional group), and the other end has chemical intimacy with the OH group on the surface of the ceramic microsphere. It consists of a polar group or a group that causes a chemical reaction, so it can be better bonded to the surface of the ceramic microsphere (filler).

According to one aspect of this embodiment, the HDPE plastic compound preferably includes 10 to 30% by weight of ceramic microspheres based on the HDPE resin. When the amount of the ceramic microspheres is less than 10% by weight, the effect of improving physical properties is insignificant and the effect of cost reduction is not significant compared to the HDPE resin. On the other hand, if the amount of ceramic microspheres is greater than 30% by weight, the effect of cost reduction is great, but the amount of inorganic materials is too large compared to HDPE resin, resulting in poor moldability and poor compatibility with HDPE.

And the HDPE plastic compound preferably contains 0.5 to 0.7% by weight of additives based on HDPE. If the amount of the additive is less than 0.5% by weight, compatibility between the ceramic microspheres and the HDPE resin is not improved, so that the effect of improving physical properties is insignificant. On the other hand, if the amount of the additive is greater than 0.7% by weight, the excess additive acts as an impurity and the physical properties of the HDPE plastic compound may deteriorate.

Next, a method for manufacturing the HDPE plastic compound for piping according to an embodiment of the present invention described above will be described.

Figure 3 is a flow chart showing a manufacturing method of the HDPE plastic compound for piping according to an embodiment of the present invention, Figure 4 is a cross-sectional view schematically showing the configuration of the extruder. Hereinafter, a method for producing a HDPE plastic compound for piping using the extruder shown in FIG. 4 will be described, but it is apparent to those skilled in the art that the extruder shown in FIG. 4 is merely illustrative. Therefore, as long as the same function is performed, an extruder having a different configuration from the extruder having the configuration shown in FIG. 4 may be used.

First, high-density polyethylene resin as a raw material, ceramic microspheres having a diameter of 1 to 20 μm, and additives are prepared (S10). As described above, ceramic microspheres can be screened from coal ash using any filtering method. In addition, the additive includes an adhesive having physical adhesion between the ceramic microspheres and the high-density polyethylene resin and/or a coupling agent that chemically bonds with the ceramic microspheres and physically adheres to the high-density polyethylene resin.

Then, the prepared raw material is injected into the extruder (S20). For example, prepared raw materials may be simultaneously injected into the extruder through a hopper (see Fig. 4). Alternatively, depending on the embodiment, after first injecting the HDPE resin and the ceramic microspheres through the hopper and then stirring them together for a predetermined time, additives are additionally injected (in this case, a separate process not shown in FIG. Additives may be injected using an injection port) or HDPE resin, ceramic microspheres, and additives may be sequentially injected while the stirring process proceeds. In this step, the amount of the raw material injected into the extruder is preferably 10 to 30% by weight of the ceramic microsphere and 0.5 to 0.7% by weight of the additive based on the HDPE resin.

Subsequently, in the extruder, the injected HDPE resin, ceramic microspheres, and additives are kneaded at a relatively high temperature of 200 to 210 ° C (S30). For example, in the extruder shown in FIG. 4 , raw materials injected through a hopper are kneaded by a screw rotating in a high-temperature cylinder, and then transferred to a die connected to a die connection unit. Then, when the mixture in the form of strands coming out through the die is cooled in a water bath and made into a certain pellet shape with a dedicated blade, the HDPE plastic compound for piping is completed.

<Test process and test result>

The HDPE resin used in the physical property test of the manufactured HDPE plastic compound for piping was YUZEX® 6100 (pipe grade) from SK Chemicals. Table 3 shows the physical properties of YUZEX® 6100 (pipe grade) provided by SK Chemicals.

First, the HDPE resin, ceramic microspheres and additives were injected into a 25 Φ extruder (see FIG. 4) and then kneaded. The amount of the injected ceramic microspheres was 10% by weight compared to the HDPE resin, and the amount of additives was varied from 1 to 8% by weight compared to the ceramic microspheres. At this time, the working temperature in the extruder was set to 200 ~ 210 ℃, the speed of the screw was set to 170rpm, to prepare the HDPE plastic compound. In addition, a specimen for evaluating the physical properties of the HDPE plastic compound prepared according to the experimental example was prepared by an injection molding machine having a clamping force of 120 tons.

Table 4 shows the types and contents of the fillers and additives used in the above experiments (here, the content ratio is the weight ratio to the HDPE resin in the case of the filler, and the weight ratio to the filler in the case of the additive). In Table 4, YD-C13, YD-C18, YD-C15, YD-C90, YD-C40, YD-C71, and YD-C92 are respectively trimethoxypropylsilane, hexadecyltrimethoxysilane, n-octyltriethoxysilane, r-mercaptopropyltrimethoxysilane, r-aminopropyltrimethoxysilane, vinyltrimethoxysilane, They are N-(B-aminoethyl)-r-aminopropyltrimethoxysilane and trimethoxypropylsilane, and YD-A50, YD-A20, YD-A03, and YD-A01 are all modified maleic anhydride polypropylenes, differing only in molecular weight.

Table 5 shows the evaluation of the physical properties of the specimens of the HDPE plastic compound for piping prepared according to the experimental example of Table 4, and FIG. 5 shows it as a graph (in FIG. 5, the horizontal axis represents the test number). At this time, the specimen was manufactured by an extruder having a clamping force of 120 tons.

Referring to Table 5 and FIG. 5, it can be seen that the change in physical properties is not large depending on the type of additive used, but the change in TE, IZOD, and FM is relatively noticeable, and in particular, the change in IZOD value is large. However, the decrease in IZOD is judged to be due to the decrease in flexibility. In particular, in the case of TE, the value is in the range of 20 to 30 and falls short of the target value of 600, but this indicates that HDPE exists in a state in which the chains inside the plastic are oriented. Since the specimen was manufactured without considering it, it can be seen that the TE also exceeds the target value according to the experimental results described later (see Tables 7 and 8).

Based on the above experimental results, six types of YD-A50, YD-A20, YD-A01, YD-A03, YD-C40 and YD-C13 with high tensile rate and high FM value were tested in extruders with a larger diameter (40Φ extruder). Additional experiments were conducted with the additives of That is, the same HDPE resin and ceramic microspheres as in the previous experiment were injected into a 40Φ extruder (see FIG. 4) and then kneaded with 6 additives. The amount of injected ceramic microspheres was varied from 10, 20 and 30% by weight compared to the HDPE resin, and the amount of additives was varied from 0.1 to 8% by weight compared to the ceramic microspheres. At this time, the working temperature in the extruder was set to 200 ~ 210 ℃, the speed of the screw was set to 320rpm, to prepare the HDPE plastic compound.

In addition, a specimen for evaluating the physical properties of the HDPE plastic compound prepared according to the experimental example was prepared by an injection molding machine having a clamping force of 120 tons. However, the evaluation of tensile strength was performed according to ASTM D Type 5 using a heating plate tester and a specimen cutter. This is because the HDPE resin is a crystalline resin and the chains inside the plastic exist in an oriented state. This is to obtain a chain orientation state.

Table 6 shows the types and contents of fillers and additives used in the experiment using the above-described 40Φ extruder (here, the content ratio is the weight ratio to the HDPE resin in the case of the filler, and the weight ratio to the filler in the case of the additive). weight ratio).

Tables 7 and 8 show the evaluation of physical properties of the specimens of the HDPE plastic compound for piping prepared according to the experimental example of Table 6, respectively. And Figure 6 shows this as a graph, and Figure 7 shows only the TE results separately (in Figures 6 and 7, the horizontal axis represents the test number).

Referring to Tables 7, 8, and 6 and 7, it can be seen that most of the additives not only show a certain tendency according to the amount, but also satisfy the target physical properties regardless of the amount within the used range. In particular, in the case of the additive YD-C13, it can be seen that the IZOD impact strength is greatly improved, and not only is the value higher than that of conventional HDPE, but also the HDT is stable. On the other hand, in the case of additive YD-C40, it can be seen that not only there is no tendency in properties except for bending properties (FS and FM), but also the physical properties do not meet the target values.

As described above, the above description is only an example and should not be construed as being limited thereto. The technical idea of the present invention should be specified only by the invention described in the claims below, and all technical ideas within the equivalent range should be interpreted as being included in the scope of the present invention. Therefore, it is obvious to those skilled in the art that the above-described embodiment can be implemented in various forms.

Claims (5)

As a high-density polyethylene (HDPE) plastic compound composition for piping,
It contains high-density polyethylene resin, ceramic microspheres (CM) with a diameter of 1 to 20 μm and additives,
With respect to the high-density polyethylene resin, the ceramic microspheres are 10 to 30% by weight and the additives are 0.5 to 0.7% by weight,
The additive includes an adhesive having physical adhesion between the ceramic microsphere and the high-density polyethylene resin and a coupling agent that chemically bonds with the ceramic microsphere and physically adheres to the high-density polyethylene resin,
The adhesive includes modified maleic anhydride grafted polypropylene, and the coupling agent is a silane-based compound, such as vinyltrimethoxysilane, r-aminopropyltrimethoxysilane, r-mercaptopropyltrimethoxysilane, N-(B-aminoethyl)-r- A plastic compound composition comprising at least one silane-based compound selected from the group consisting of aminopropyltrimethoxysilane, n-octyltriethoxysilane, hexadecyltrimethoxysilane, and alkyltrimethoxysilane (here, alkyl has a C of 2 to 8).
delete delete As a method for producing a high-density polyethylene (HDPE) plastic compound for piping,
Injecting high-density polyethylene resin, ceramic microspheres (CM) having a diameter of 1 to 20 μm, and additives into an extruder, respectively; and
Kneading the high-density polyethylene resin, the ceramic microspheres, and the additives at a temperature of 200 to 210 ° C. in the extruder,
With respect to the high-density polyethylene resin, the ceramic microspheres are 10 to 30% by weight and the additives are 0.5 to 0.7% by weight,
The additive includes an adhesive having physical adhesion between the ceramic microsphere and the high-density polyethylene resin, and a coupling agent that chemically bonds with the ceramic microsphere and physically adheres to the high-density polyethylene resin,
The adhesive includes modified maleic anhydride grafted polypropylene, and the coupling agent includes vinyltrimethoxysilane, r-aminopropyltrimethoxysilane, r-mercaptopropyltrimethoxysilane, N-(B-aminoethyl)-r-aminopropyltrimethoxysilane, n-octyltriethoxysilane, A method for producing a plastic compound comprising at least one silane-based compound selected from the group consisting of hexadecyltrimethoxysilane and alkyltrimethoxysilane (where C is 2 to 8). delete

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