JP4875458B2 - Production method of regenerated PET pseudo-bamboo and regenerated PET pseudo-bamboo thereby - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recycled PET fake bamboo which employs recycled PET bottles and has excellent heat and impact resistances. <P>SOLUTION: A method of producing a recycled PET fake bamboo uses a recycled PET resin formed by mixing 70 wt.% of a pulverized product of PET bottles with 12 wt.% of a high-density polyethylene and 9 wt.% of a thickener to prevent drawing down and comprises extruding the recycled PET resin into a fake bamboo 1 in a form of a hollow pipe having a circular cross section, transferring the bamboo 1 on a roller by 1.5 m and cooling gradually to form a crystallized layer 11 inside the bamboo 1 and cooling the resultant body rapidly so that the bamboo 1 gets a laminate structure composed of an inner crystallized layer 11 and an outer amorphous layer 12. Having the laminate structure, the fake bamboo 1 has a high heat resistance which causes no deformation in a 110&deg;C-by-20-min heat resistance test under a load of 200 grams and a high impact resistance which achieves an impact resistance of 9.0-9.5 kJ/m<SP>2</SP>in an Izod impact resistance test, realizing a recycled PET fake bamboo 1 having heat and impact resistances higher than those of fake bamboos made of ABS resins. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a method for producing regenerated PET pseudobamboo using regenerated PET resin as a raw material, and a regenerated PET pseudobamboo thereby.

This kind of artificial bamboo is produced by extrusion molding into a hollow pipe shape using, for example, an ABS resin. At this time, the production is generally performed by an extrusion molding process, a water cooling process of the extruded material, an extruded material. It is supposed to be performed by a series of steps including a cutting step of a predetermined length. The ABS resin pseudo-bamboo, for example, is a substitute for the PVC resin, whereas the PVC resin pseudo-bamboo had a heat resistance of about 63 to 65 ° C. due to its low glass transition point. As a result, the heat resistance of the artificial bamboo is improved to about 85 ° C. so that it can be used outdoors exposed to direct sunlight in summer, for example. Since it can assume about 3 kJ / m ² , it is generally possible to prevent the occurrence of cracks due to nailing except in a cold atmosphere such as outdoors in winter.

On the other hand, recycling of PET bottles is particularly required by the Containers and Packaging Recycling Law, but the recycling of PET, that is, polyethylene terephthalate, is generally used as an additive to fibers, sheets, injection molded products, and PET bottle materials. However, when extrusion molding with recycled PET resin, especially extrusion molding of hollow pipe-shaped pseudo bamboo material, the melt viscosity of recycled PET is low, so the drawdown phenomenon is exhibited and the shape retention of the hollow pipe shape is maintained. Can not be. On the other hand, the present inventor mainly uses a pulverized product obtained by pulverizing a used PET bottle as a recycled PET resin capable of eliminating the drawdown by improving the melt viscosity. It has been proposed to produce pseudo-bamboo by extrusion molding using a material that has been re-pelletized with the addition of a sticky agent. According to this, the high-density polyethylene of the above-mentioned high-density polyethylene with respect to a pulverized product obtained by pulverizing a used PET bottle in the recycled PET resin The weight ratio is 10 ± 5 wt%, and the thickener is a polymer of an acrylate or methacrylate having a reactive group with the recycled PET resin and a vinyl monomer copolymerizable therewith, and the recycled The vinyl monomer weight ratio of the PET resin to the pulverized product obtained by pulverizing the used PET bottle is 7 ± 5 wt%. In addition to eliminating the drawdown, in the impact resistance test by the Izod method, about 9.0 kJ / m ² to 9.5 kJ / of the pseudo bamboo using the ABS resin is about 7.3 kJ / m ² . It can be considered to exhibit an impact resistance of m ² or more, and can eliminate the occurrence of cracks caused by nailing in the cold atmosphere outdoors in the winter, as seen in the ABS-based artificial bamboo. The impact resistance will be greatly improved, and it will be possible to put into practical use recycled PET pseudo-bamboo that is particularly excellent in impact resistance.

JP 2006-123268 A Japanese Patent Application No. 2006-291385

  However, while the artificial bamboo using this recycled PET resin can prevent the above-mentioned drawdown and can be made excellent in impact resistance, its heat resistance is different from that of the above-mentioned PVC-based resin artificial bamboo. The temperature is as low as 67 ° C, which is similar to that of the PVC-based resin pseudo-bamboo. Deformation caused by direct sunlight in the summer, for example, the ends of the pseudo-bamboo erected between the pillars hang down. There is a possibility that a gap will be formed between them, and for example, if it is used for a partition near the source in a hot spring area, or if it is washed with hot spring water near the source, it may be deformed. Compared to bamboo, although it is superior in impact resistance, there is a problem that it is greatly inferior in heat resistance, so even if it can be recycled as a PET bottle and can be made a pseudo bamboo with excellent impact resistance, In addition, low heat resistance There remains a possibility that the spread is prevented by the.

  The present invention has been made in view of the above circumstances, and the problem to be solved is to provide a production method of regenerated PET pseudobamboo excellent in heat resistance and suitable for indoor and outdoor use, and regenerated PET pseudobamboo thereby There is.

  As a result of diligent research in line with the above-mentioned problems, a pseudo-plastic extruded into a hollow pipe using the recycled PET resin improved in melt viscosity by adding high-density polyethylene and a thickener so as to prevent drawdown. The bamboo is slowly cooled and the temperature of the inner peripheral surface separated from the outside air by the hollow portion of the pseudo bamboo is maintained at a high temperature, and the extrusion temperature of the pseudo bamboo, that is, the melting temperature of the recycled PET resin is about 250 ° C. The crystallization start temperature, which is somewhat reduced from the initial temperature, that is, about 220 ° C. to 200 ° C., is gradually lowered, and the partial crystallization from the inner peripheral surface side of the pseudo bamboo material toward the thickness direction (Recrystallization) is advanced to form a crystallized layer having a cross-sectional shape that follows the inner peripheral surface on the inner peripheral surface side, and after forming the crystallized layer, the pseudo bamboo material is rapidly cooled to crystallize the crystallized layer. Stop and hide the rest of the artificial bamboo By using a crystallized layer (amorphous layer) to make the pseudo bamboo material a laminated structure having an inner crystallized layer and an outer non-crystallized layer, the pseudo bamboo material has extremely high heat resistance. For example, when a heat resistance test is performed for 20 minutes in a high temperature atmosphere of 110 ° C. with a load of 200 g applied to the artificial bamboo material, the upper and lower surfaces of the ABS resin artificial bamboo material are flattened. The deformed bamboo material of the recycled PET resin, while deformed into a state of being crushed to a height of about 2/3, has secured a high heat resistance that maintains the original shape as it is and does not deform at all. It came to the knowledge that it could be done. That is, this is because when the pseudo-bamboo material of PET resin is subjected to a high temperature, even if the non-crystallized layer on the outer peripheral side softens, the crystallized layer located on the inner peripheral surface side does not soften. As a result of the action of the crystallized layer attached to the inner peripheral surface on the inner peripheral surface side to form a heat-resistant reinforcing core that retains the softened non-crystallized layer located on the outer peripheral side, It seems to maintain the cross-sectional shape and ensure its shape retention. At this time, although a crystallized layer is formed on the inner peripheral surface side, this is partial in the thickness direction, and the outer peripheral side forms a non-crystallized layer, thereby giving a texture as a pseudo bamboo material such as elastic modulus and elongation rate. As a recycled PET resin with improved melt viscosity added with the above-mentioned high-density polyethylene and a thickener, it is possible to use conventional ABS resin as recycled recycled PET pseudo-bamboo such as PET bottles. It has both advanced heat resistance and impact resistance that exceed those of other bamboos, and it is possible to put to practical use an excellent pseudobamboo that does not generate cracks even when used outdoors or when deformed in the summer or nailing in a cold atmosphere. It becomes possible.

  The present invention has been made on the basis of such knowledge. That is, the invention according to claim 1 is an extrusion method in which a hollow pipe-like pseudo bamboo material is extruded using a recycled PET resin to which high-density polyethylene and a thickener are added. An inner periphery by providing a forming step, a slow cooling step of partially crystallizing the inner peripheral surface side of the extruded pseudo bamboo material in the thickness direction, and a rapid cooling step of rapidly cooling the pseudo bamboo material to stop crystallization. A method for producing recycled PET pseudo-bamboo is characterized in that a crystallized layer having a cross-sectional shape following the inner peripheral surface is formed on the surface side.

  In addition to the above, the invention according to claim 2 is characterized in that the thickness of the crystallized layer on the inner peripheral surface side is 20 ± 5% in the thickness direction from the inner peripheral surface of the hollow pipe-shaped pseudo bamboo. Can be suitable for securing the texture of the artificial bamboo material and securing the high heat resistance and impact resistance, and this is achieved by crystallization on the inner peripheral surface side by the slow cooling step and the rapid cooling step. 2. The method according to claim 1, wherein the layer is formed to a thickness of 20 ± 5% from the inner peripheral surface side toward the thickness direction.

  In the invention of claim 3, in addition to the above, in the slow cooling step, the pseudo bamboo material extruded by avoiding a rapid temperature change may be set as the recrystallization start temperature. As such, since it is hardly affected by the factory ambient temperature, it is only necessary to transfer the extruded pseudo-bamboo material in the extrusion direction at room temperature, and the rapid cooling process should stop crystallization due to the transfer. Therefore, it is sufficient to immerse the pseudo-bamboo material so that it passes through the cooling water. This makes it as simple and reliable as possible that the pseudo-bamboo material has a laminated structure of the crystallized layer and the non-crystallized layer. The slow cooling step is performed by transferring the extruded pseudo bamboo material at room temperature, and the rapid cooling step is performed by immersing the pseudo bamboo material in cooling water. Claims made It is obtained by a method for producing recycled PET 擬竹 according to 1 or 2.

  In addition to the above, the invention described in claim 4 and claim 5 is to improve the commercial value of the recycled PET pseudo-bamboo as having the texture and shape of natural bamboo as much as possible. The invention according to claim 4 is provided with the texture of the natural bamboo, and in addition to the extrusion process, the slow cooling process and the rapid cooling process, the extrusion is simultaneously performed with the pseudo bamboo material extrusion process. It has a colored film layer forming step in which a colored film layer is coated on the surface of the pseudo bamboo material by extrusion molding at the same speed as that of the speed or after the cutting process after the rapid cooling process by extrusion molding at the same speed as the feed speed of the pseudo bamboo material. A method for producing regenerated PET pseudo-bamboo according to claim 1, 2 or 3, wherein the invention according to claim 5 is provided with the shape of the natural bamboo, Slow cooling process and rapid cooling process In addition, a colored film layer is formed on the surface of the pseudo bamboo material by performing intermittent vacuum suction on the pseudo bamboo material immediately after the extrusion molding process or by performing extrusion molding at the same speed as the feed speed of the pseudo bamboo material after passing through the cutting process after the quenching process. And an additional colored film layer forming step of covering and forming the artificial bamboo material by intermittently stopping the pseudo bamboo material to form a gathering of the colored film layer. Item 4. A method for producing recycled PET pseudo-bamboo according to Item 1, 2 or 3.

  According to the sixth aspect of the present invention, the inner crystallized layer and the outer peripheral side of the inner crystallized layer are formed by forming a crystallized layer having a cross-sectional shape along the inner peripheral surface by partially forming in the thickness direction on the inner peripheral surface side. In order to provide a pseudo bamboo with an extremely high heat resistance and a texture such as elastic modulus and elongation by providing a laminated structure with a non-crystallized layer, this is combined with high-density polyethylene and thickened Forming a crystallized layer having a cross-sectional shape that follows the inner peripheral surface by forming a hollow pipe shape that is extruded using a recycled PET resin to which an agent is added and is partially in the thickness direction on the inner peripheral surface side. It is a characteristic recycled PET pseudo-bamboo.

  In addition to the above, the invention according to a seventh aspect of the invention secures the texture of the artificial bamboo and makes the crystallized layer 20 ± 5% thick from the inner peripheral surface toward the thickness direction. In order to ensure high heat resistance and impact resistance, the crystallized layer is formed to a thickness of 20 ± 5% from the inner peripheral surface toward the thickness direction. The recycled PET pseudo-bamboo according to claim 6, wherein the recycled PET pseudo-bamboo is used.

  The present invention is a means for solving the above problems as the gist of the invention.

  Since the present invention is configured as described above, the invention according to claim 1 is extruded into a hollow pipe shape using a recycled PET resin to which high-density polyethylene and a thickener are added so as to prevent drawdown. The simulated bamboo material is gradually cooled, the temperature on the inner peripheral surface side isolated from the outside air by the hollow portion of the artificial bamboo material is maintained at a high temperature, and the extrusion temperature of the artificial bamboo material, that is, about 250 ° C. of the recycled PET resin. A recrystallization start temperature slightly lowered from the melting temperature, that is, about 220 ° C. to 200 ° C., is performed so that the temperature gradually decreases. Crystallization (recrystallization) is progressed to form a crystallized layer having a cross-sectional shape along the inner peripheral surface on the inner peripheral surface side, and after the formation of the crystallized layer, the pseudo bamboo material is quenched and crystallized. Cease, and the rest of the pseudo bamboo The pseudo-bamboo material is formed into a laminated structure having an inner crystallized layer and an outer non-crystallized layer in a high temperature atmosphere of 110 ° C. with a load of 200 g applied thereto. Even in a heat test exposed for a minute, the original shape of extrusion can be maintained as it is, and high heat resistance can be ensured without deformation at all, and the non-crystallized layer ensures the texture as a pseudo bamboo material such as elastic modulus and elongation. Thus, it is possible to provide a method for producing recycled PET pseudo-bamboo suitable for indoor and outdoor use. Therefore, at this time, by using the recycled PET resin with the melt viscosity improved and the above-mentioned high-density polyethylene and a thickener added, the recycled ABS pseudo-bamboo recycled from PET bottles etc. It is possible to put to practical use an excellent artificial bamboo that has both high heat resistance and impact resistance exceeding the above, and that does not generate cracks even when used outdoors or without deformation in the summer or nailing in a cold atmosphere.

  In addition to the above, the invention according to claim 2 is characterized in that the thickness of the crystallized layer on the inner peripheral surface side is 20 ± 5% in the thickness direction from the inner peripheral surface of the hollow pipe-shaped pseudo bamboo. By doing so, it is possible to ensure the texture of the artificial bamboo and to ensure the high heat resistance and impact resistance.

  In addition to the above, the invention according to claim 3 performs the slow cooling step by transferring the extruded pseudo-bamboo material in the direction of extrusion at room temperature, and the quenching step passes through the cooling water. By immersing the pseudo-bamboo material, a pseudo-bamboo material having a laminated structure of a crystallized layer and a non-crystallized layer can be formed as easily and reliably as possible.

  In addition to the above, the invention described in claim 4 and claim 5 has a recycled PET pseudo bamboo having the texture and shape of natural bamboo as much as possible. It is assumed that the texture of natural bamboo is provided, and the invention according to claim 5 may be provided with the shape of the natural bamboo.

  According to the sixth aspect of the present invention, the inner crystallized layer and the outer peripheral side of the inner crystallized layer are formed by forming a crystallized layer having a cross-sectional shape along the inner peripheral surface by partially forming in the thickness direction on the inner peripheral surface side. Providing artificial bamboo suitable for indoor and outdoor use by ensuring a very high heat resistance by making it a laminated structure with non-crystallized layer and securing the texture as an artificial bamboo material such as elastic modulus and elongation. Can do.

  In addition to the above, the invention according to a seventh aspect of the invention secures the texture of the artificial bamboo and makes the crystallized layer 20 ± 5% thick from the inner peripheral surface toward the thickness direction. It can be made suitable for ensuring high heat resistance and impact resistance.

  Hereinafter, the present invention will be described in more detail with reference to the example of the drawings. Reference numeral 1 denotes a recycled PET pseudo-bamboo, and the recycled PET pseudo-bamboo 1 is a recycled PET obtained by adding high-density polyethylene and a thickener to the raw resin. The resin is made into a hollow pipe formed by extrusion using the recycled PET resin, and the crystallization layer 11 having a cross-sectional shape is formed on the inner peripheral surface side of the inner peripheral surface so as to follow the inner peripheral surface. In this example, the recycled PET pseudo-bamboo 1 is PET, especially a PET bottle recycled pseudo-bamboo that is obtained by recycling a PET bottle. At this time, the recycled PET resin of the pseudo-bamboo 1 is used to grind used PET bottles. The melt viscosity is improved by using the pulverized product as the main component and re-pelletized with high-density polyethylene and thickener added to it, thereby securing the tension of the pseudo-bamboo material extruded. Te, some as being a hollow pipe shape to prevent drawdown accompanying the extrusion of PET resin.

  The pseudo bamboo 1 of this example has a hollow pipe-like cross-sectional shape with a circular shape, an outer diameter of, for example, about 2 to 2.5 cm, a wall thickness of about 2 to 3 mm, and an outer diameter of a node 2 portion described later. About 2.5 to 3 cm, an extruded pseudo bamboo material is cut into a predetermined length so as to have a long bar shape having an appropriate length. It is provided with a coloring coating layer 13 which will be described later and a groove 2 which is raised intermittently in the longitudinal direction on the outer peripheral side and a groove 3 which extends from the node 2 in the longitudinal direction. It is as high quality as possible with the texture of natural bamboo, with the color tone of bamboo and the like, and the grooves and strips seen in the section 2 and branching parts.

In this example, the recycled PET resin pseudo-bamboo 1 having a circular pipe shape with a circular cross-section has a partial crystallized layer 11 directed from the inner peripheral surface side toward the thickness direction on the inner peripheral surface side. The inner crystallized layer 11 and the outer peripheral non-crystallized layer 12 are provided by forming the remainder of the non-crystallized layer 12 in the thickness direction of 20 ± 5%. Thus, the pseudo-bamboo 1 has both a high degree of heat resistance and impact resistance as well as texture such as elastic modulus and elongation. In other words, pseudo bamboo 1 is assumed to have no deformation at all while maintaining the original circular shape in a heat resistance test in which a load of 200 g is applied and exposed to a high temperature atmosphere of 110 ° C. for 20 minutes. By making the recycled PET resin having improved melt viscosity the above-mentioned high-density polyethylene and a thickener, 9.0 kJ / m ^{2 to} 9.5 kJ / m ² or more in an Izod impact test It exhibits high impact resistance. In other words, in the above heat resistance test, the upper and lower surfaces of the pseudo-bamboo of the ABS resin having the same cross-sectional circular hollow pipe shape, which has been widely used for a long time, are considered to have excellent impact resistance and heat resistance. 2) and the impact resistance by the Izod method is only about 7.3 kJ / m ^2. Therefore, the recycled PET pseudo-bamboo 1 is a pseudo-bamboo of the ABS resin. Both high heat resistance and impact resistance, which greatly exceed both heat resistance and impact resistance, can be used outdoors, so that cracks can be generated even when used outdoors or when nailing in a cold atmosphere. It has been resolved.

  The high heat resistance is such that the crystallized layer 11 attached to the inner peripheral surface on the inner peripheral surface side of the recycled PET resin pseudo-bamboo 1 forms a heat-resistant reinforcing core and is softened by high temperature on the outer non-crystallized layer. It seems that the shape of the artificial bamboo 1 is retained by acting so as to retain the shape of the inside 12 and that the high impact resistance is the property of the recycled PET resin due to the high density of the high density polyethylene. This is considered to contribute to increasing the density of the artificial bamboo 1 by improving the above.

  The PET recycled pseudo bamboo 1 of this example formed in this way will be explained by its production method. The pseudo bamboo 1 is a hollow pipe-shaped pseudo bamboo using a recycled PET resin to which high density polyethylene and a thickener are added. An extrusion process for extruding bamboo material, a slow cooling process for partially crystallizing the inner peripheral surface side of the extruded pseudo bamboo material in a thickness direction, and a rapid cooling process for quenching the pseudo bamboo material to stop crystallization A crystallized layer having a cross-sectional shape that follows the inner peripheral surface is formed on the inner peripheral surface side, and then the pseudo bamboo 1 having the appropriate length is obtained through a conventional cutting process. At this time, in this example, in addition to the extrusion molding process, the slow cooling process, and the rapid cooling process, the surface of the pseudo bamboo material is subjected to the extrusion molding process at the same speed as the extrusion molding process of the pseudo bamboo material. Colored film that coats and forms a colored film layer In addition to the above-described extrusion process, slow cooling process and rapid cooling process, there is also a knotting process for knotting the pseudo-bamboo material by applying intermittent vacuum suction to the pseudo-bamboo material immediately after the extrusion process. As a result, the pseudo-bamboo 1 is provided with the above-mentioned colored coating layer and the node 2 and is made of a high-quality material that exhibits the texture of natural bamboo as much as possible, and the production method is a series of continuous processes. Productivity can be maintained as high as possible.

  The recycled PET resin whose melt viscosity has been improved by adding the high density polyethylene and the thickener in this example is obtained by re-pelletizing the high density polyethylene and the thickener added to the pulverized product obtained by pulverizing the used PET bottle. In this example, the recycled PET resin has a weight ratio of 10 ± 5 wt% of the high-density polyethylene to the pulverized product obtained by pulverizing the used PET bottle, and the thickener is Weight of the vinyl monomer with respect to a pulverized product obtained by pulverizing a used PET bottle in the recycled PET resin as a polymer of acrylate or methacrylate having a reactive group with the PET resin and a vinyl monomer copolymerizable therewith The ratio is 7 ± 5 wt%. At this time, the thickener of this example is the above acrylate or methacrylate. A polymer coated with the vinyl monomer is used. In addition, the recycled PET resin in this example is further added with a compatibilizing agent, a lubricant and a pigment, such as an ocher pigment, in addition to the high-density polyethylene and the thickener, and is simulated by the compatibilizing agent and the lubricant. The extrusion formability as bamboo 1 is improved, and the pseudo-bamboo material extruded by the above pigment is made ocher, and the cut surface of pseudo-bamboo 1 exhibits the color tone of natural bamboo in a dry state.

That is, high-density polyethylene is extremely effective in securing high impact resistance in the artificial bamboo 1, but it can be used at the time of extrusion molding by using it together with a thickener on the pulverized material of used PET bottles. Synergistically improving the melt viscosity to effectively prevent drawdown, and the above-mentioned extrusion molding and knotting are considered to be effective in producing pseudo bamboo 1 as a series of continuous processes. The density of the high-density polyethylene is preferably 0.945 to 0.970 g / m ³ and a melt index in the range of 0.001 to 20 g / 10 minutes. Further, as the thickener, a polymer obtained by polymerizing the recycled PET resin, an acrylate or methacrylate having a reactive group, and a vinyl monomer copolymerizable therewith can be used singly or plurally. Examples of the methacrylate include epoxy groups such as glycidyl acrylate and glycidyl methacrylate, and examples of the vinyl monomer polymerized with these acrylate or methacrylate include aromatic compounds such as styrene, α-methylstyrene, and chlorostyrene. It is preferable to use an aromatic vinyl monomer or a vinyl cyanide monomer such as acrylonitrile or methacrylonitrile, and the molecular weight of the polymer is preferably 40,000 to 150,000. Examples of the thickener further include alkyl acrylates having 8 carbon atoms such as 2-ethylhexyl acrylate, butyl acrylate, ethyl acrylate, and methyl acrylate, alkyls such as 2-ethylhexyl methacrylate, butyl methacrylate, ethyl methacrylate, and methyl methacrylate. By adding an alkyl methacrylate having 8 carbon atoms, the polymerization can be performed, for example, by suspension polymerization or emulsion polymerization.

  Thus, when adding the high density polyethylene and the thickener to the pulverized material of the PET bottle, the weight ratio of the high density polyethylene to the pulverized material is 10 ± 5 wt%, and the weight ratio of the thickener is 7 ± 5 wt%. By increasing the above-mentioned high impact resistance and melt viscosity of the recycled PET resin, sufficient tension is applied to the extruded pseudo-bamboo material to effectively draw down from the extrusion process to the quenching process. Thus, a hollow pipe-like pseudo bamboo material having a circular cross-section can be obtained.

In the extrusion process, the recycled PET resin formed by adding high-density polyethylene and a thickener is supplied with pellets from a hopper according to a conventional method to an extruder, for example, a melt viscosity of 4.80 × 10 ^−3. This is done by extruding the pseudo-bamboo material at ˜8.00 × 10 ⁻³ (Pa · s).

  At this time, the colored film layer forming step at the same time as the extrusion forming step is carried out from the hopper to the extrusion forming device for forming the coating layer continuously arranged in the pseudo-bamboo material extrusion molding machine. It is only necessary to supply a plastic resin and simultaneously extrude the pseudo-bamboo material by extrusion molding of recycled PET resin so that the surface, that is, the outer peripheral surface is covered with the colored coating layer 13. The colored coating layer 13 is double-supplied to the pseudo-bamboo material, so that, for example, the inner and outer multi-layers, particularly two different color layers are laminated, and the outer layer has a different thickness in the outer circumferential direction. By forming the color tone part of the thick outer layer and the composite color tone part of the thin outer layer and the inner layer, the color tone of the bamboo, dead bamboo, bamboo bamboo, etc. is changed by the color tone that changes in the outer circumferential direction of the pseudo bamboo material. Has the texture found in natural bamboo Nasu shading patterns are to be exposed.

  Further, the knotting step immediately after the extrusion molding process, in this example immediately after the colored film layer forming process, moves the pseudo bamboo material immediately after the extrusion molding at the same speed as the extrusion speed by forming a knot forming groove. In a molten state that can be vacuum-molded immediately after extrusion molding by holding the knot forming groove in a vacuum while holding the mold in a fixed position so as to reciprocate and return to the home position. The pseudo-bamboo material having a temperature higher than about 220 ° C., preferably about 230 ° C. or higher, at which recrystallization starts, is intermittently raised in the longitudinal direction by the above-mentioned ridges 2 by the raised ribs of the surface raised by the vacuum forming. In this example, by forming a plurality of, for example, a pair of knot forming grooves in the extrusion direction in the mold, a pair of the above-mentioned raised ribs is formed, for example, to have an M-shaped cross section. It is arranged. At this time, the pseudo-bamboo material of the present example is further partially raised in the outer circumferential direction continuously to one of the knot forming grooves in the above-mentioned mold for forming the knot, and is tapered in the extruding direction and gradually reduces the raised height. And forming a groove 3 between the raised ribs corresponding to the raised protrusions in the longitudinal direction of the pseudo bamboo material from the raised ribs having the M-shaped cross section. The shape is similar to that of natural bamboo by adding grooves and strips that are seen in the branching part that continues to the bamboo knot.

  In this example, the pseudo bamboo material in which the colored coating layer 13 is formed and the nodes 2 and the grooves 3 are formed is subjected to the slow cooling step and the rapid cooling step, whereby the pseudo bamboo material is obtained. A laminated structure of the crystallized layer 11 and the non-crystallized layer 12 is formed, and in the present example, the slow cooling step is performed by transferring an extruded pseudo bamboo material at room temperature and The rapid cooling process is performed by immersing the pseudo bamboo in cooling water. At this time, the crystallization layer on the inner peripheral surface side by the slow cooling process and the rapid cooling process is the same as the inner peripheral surface side. The thickness is 20 ± 5% in the thickness direction.

  That is, the pseudo bamboo material can ensure its high heat resistance by forming a crystallized layer 11 having a circular cross-sectional shape along the inner peripheral surface, in this example, a circular cross-sectional shape, on the inner peripheral surface side. As a result, the formation of the crystallized layer by the slow cooling process of this example can be achieved by gradually extruding the extruded pseudo-bamboo material through its recrystallization start temperature of about 220 ° C. to 200 ° C. Well, the hollow part of the pseudo-bamboo material that has been extruded is hardly affected by the ambient temperature of the factory. Therefore, the moderate temperature can be reduced by transporting the extruded pseudo-bamboo material in the direction of extrusion at room temperature. The temperature is lowered and the above slow cooling step is performed to form the slow cooling and the crystallized layer 11 on the inner peripheral surface side. Further, after the crystallization in the slow cooling step, if it is cooled at once to stop it, the remainder can be made into the non-crystallized layer 12, but the rapid cooling step is performed on the inner peripheral surface side. This can be done by bringing the pseudo-bamboo material crystallized into contact with cooling water, and stopping the crystallization by the rapid cooling process in this example is by immersing the extruded pseudo-bamboo material in a water tank placed in series in the extrusion direction. By passing the cooling water and cooling the inner peripheral surface and the outer peripheral surface of the pseudo bamboo material with the cooling water, the rapid cooling step is performed, and the crystallization layer 11 is formed on the inner peripheral surface side by the rapid cooling. And a remaining layer of the non-crystallized layer 12.

  At this time, the slow cooling process is carried out by, for example, extruding pseudo bamboo material, in this example, pseudo bamboo material that has undergone a knotting process with respect to the pseudo bamboo material at about 230 ° C., for example, 0.5 m to 2 m, preferably 0. Although it varies depending on the distance range of 5m to 1.5m and the extrusion speed, when converted into time, it is transferred horizontally on the roller in the extrusion direction at room temperature, for example, 0.3 to 1.3 minutes, preferably 0.3 to 1 minute. To do as you do. At this time, when the distance range is less than 0.5 m and time conversion is less than 0.3 minutes, the formation of the crystallized layer 11 becomes insufficient, and the thickness of the crystallized layer 11 in the pseudo-bamboo material is in the thickness direction from the inner peripheral surface side. As a result of being less than 15% toward the above, it tends to exhibit some deformation when exposed to the high temperature of 110 ° C., and the heat resistance cannot be sufficiently secured, while the distance range is 1.5 m, When the time conversion exceeds 1 minute, the formation of the crystallized layer 11 becomes excessive, and as a result of the thickness of the crystallized layer 11 in the pseudo-bamboo material similarly exceeding 25%, the elastic modulus as the pseudo-bamboo material decreases. The suppleness is impaired and the texture of natural bamboo tends not to be obtained. If the distance range exceeds 2 m and the time conversion is 1.3 minutes, the transfer time is too long and the shape of the pseudo bamboo is changed due to drawdown. Of elastic modulus Since the lower becomes difficult to secure a texture of large natural bamboo, The sustained cold process, one of the distance range to a time range, it is particularly to those of the above preferred ranges.

  Although normal temperature running water can be used as the cooling water, it is preferable to use the cooling water stored in the aquarium. At this time, the temperature rise is large by cooling the pseudo bamboo material in the slow cooling state. The water is preferably circulated from the water tank to the water tank again via a heat exchanger so that there is no cooling failure due to temperature rise.

As an example, for example, 70 wt% of a pulverized PET bottle, 12 wt% of high-density polyethylene, and 9 wt% of a thickening agent are used in combination. The extrusion melting temperature is 230 ° C., the screw rotation speed is 50 rpm, and the discharge rate is 3 kg / h. Bamboo material is subjected to a slow cooling process by transferring it on a roller at 1.5 m at normal temperature for 1 minute on a time basis, followed by a quenching process by passing 5 ° C. cooling water in a water tank, and then cutting to a predetermined length by a cutting process. Thus, the above-mentioned pseudo-bamboo 1 with a circular hollow pipe having a thickness of 3 mm and provided with a colored coating layer was obtained. The pseudo-bamboo 1 could have a texture similar to that of a natural bamboo having no drawdown, a circular cross section, nodes and grooves at predetermined intervals, and a colored coating layer on the surface. Using a specimen of 5 cm in length of the artificial bamboo 1, a metal plate was placed on the specimen, a 200 g load was applied, and it was placed in a 110 ° C. heating furnace for 20 minutes in the high temperature atmosphere at 110 ° C. As a result of performing a heat resistance test for 20 minutes, pseudo bamboo 1 maintained its original circular hollow shape as it was, and no deformation was seen including the metal plate mounting portion. As a comparative example, the same heat resistance test was carried out using a 5 cm long specimen of a 3 cm thick pseudo bamboo with the same shape as a conventional ABS resin pseudo bamboo. Was flattened to a height of about 2/3 so as to flatten. Similarly, when an impact resistance test (23 ° C.) by the Izod method was conducted using a test piece having a thickness of 3 mm, the result was 9.3 kJ / m ² . As a comparative example, an impact resistance test using a 3 mm-thick test piece of the conventional ABS resin pseudo-bamboo was performed, and the result was 7.3 kJ / m ² . Accordingly, it was confirmed that the heat resistance and impact resistance of the examples greatly exceeded the comparative examples.

  In the above example, the colored film layer forming process is performed by the extrusion process at the same speed as the extrusion speed at the same time as the pseudo bamboo material extrusion process, but if necessary, the cutting process after the rapid cooling process. After passing through the process, the colored bamboo layer is coated on the surface of the artificial bamboo material by extrusion molding at the same speed as the feed speed of the artificial bamboo material. This was done by intermittent vacuum suction on the pseudo bamboo immediately after the molding process, but if necessary, extrusion molding at the same speed as the feed speed of the pseudo bamboo after the cutting process after the rapid cooling process. In the above-described colored film layer forming step, which forms a colored film layer on the surface of the artificial bamboo material, the pseudo bamboo material is intermittently stopped to form a gathering of the colored film layer, so that the pseudo bamboo material is also knotted. In In the practice of the present invention, including the same batch type as described above, recycled PET resin, extrusion molding process, slow cooling process, rapid cooling process, colored film layer forming process used as necessary, Each specific method such as knotting process, material, composition, ratio, etc. Each concrete shape, structure, etc. of pseudo bamboo, its crystallized layer, etc. It can be various as long as it is not contrary.

It is a perspective view of the artificial bamboo with a knot. It is sectional drawing of the artificial bamboo with a node. It is a partial expanded longitudinal cross-sectional view which shows the lamination | stacking model of a crystallized layer and a non-crystallized layer.

1 Pseudo bamboo 2 Section 3 Groove 11 Crystallized layer 12 Non-crystallized layer 13 Colored coating layer

Claims (7)

  Extrusion process to extrude a hollow pipe-like pseudo bamboo material using recycled PET resin with high density polyethylene and thickener added, and the inner peripheral surface side of the extruded pseudo bamboo material is partially crystallized in the thickness direction And forming a crystallized layer having a cross-sectional shape along the inner peripheral surface on the inner peripheral surface side by providing a slow cooling step for converting to a rapid cooling step for rapidly cooling the pseudo bamboo material to stop crystallization. Production method of recycled PET artificial bamboo.   The crystallization layer on the inner peripheral surface side by the slow cooling step and the rapid cooling step is formed to a thickness of 20 ± 5% from the inner peripheral surface side toward the thickness direction. Production method of recycled PET artificial bamboo.   3. The slow cooling step is performed by transferring an extruded pseudo bamboo material at room temperature, and the quenching step is performed by immersing the pseudo bamboo material in cooling water. Production method of recycled PET artificial bamboo.   In addition to the above-mentioned extrusion molding process, slow cooling process and rapid cooling process, the pseudo bamboo material feed rate by the extrusion molding process of the above-mentioned pseudo bamboo material at the same time as the extrusion molding speed or the cutting process after the rapid cooling process A method for producing recycled PET pseudo-bamboo according to claim 1, 2 or 3, further comprising a colored film layer forming step of coating a colored film layer on the surface of the pseudo-bamboo material by extrusion molding at the same speed.   In addition to the above extrusion molding process, slow cooling process and rapid cooling process, by applying intermittent vacuum suction to the pseudo bamboo immediately after the extrusion molding process or after the cutting process after the rapid cooling process, the same speed as the feed speed of the pseudo bamboo material In the additional colored film layer formation process, the pseudo bamboo material is intermittently stopped in the additional colored film layer forming process to form the gathering of the colored film layer by extruding the surface of the artificial bamboo material. A method for producing recycled PET pseudo-bamboo according to claim 1, 2 or 3, further comprising a knotting step for performing the step.   A hollow pipe formed by extrusion molding using recycled PET resin to which high-density polyethylene and a thickener are added is formed into a crystallization layer having a cross-sectional shape that is partially formed in the thickness direction on the inner peripheral surface side and that follows the inner peripheral surface. Regenerated PET pseudo-bamboo characterized by being formed.   The regenerated PET pseudo-bamboo according to claim 6, wherein the crystallized layer is formed to a thickness of 20 ± 5% from the inner peripheral surface side toward the thickness direction.

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