JP2004168892A - Resin molded product and method for producing resin molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin molded product having a precisely formed grain pattern in a stripe shape; and to provide a method for producing the molded product. <P>SOLUTION: The resin molded product is produced by mixing color pellets comprising an acrylic resin and a pigment, with a mixed material comprising cellulosic fine particles and a polyolefin-based resin, and melting the resultant mixture and subjecting the melted mixture to extrusion molding to form a desired shape. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a resin molded product containing fine cellulose particles and a polyolefin resin, and a method for producing a resin molded product.
[0002]
[Background technology]
Conventionally, cellulose-based fine particles obtained by finely pulverizing a cellulose material and a resin or the like are mixed together and formed into a desired shape by extrusion molding or injection molding. 2. Description of the Related Art Production of molded articles is performed. With respect to such a resin molded product, there is a demand for a molded product having not only a woody appearance but also a high design property, that is, a wood grain pattern such as natural wood. Therefore, in general, a wood grain pattern is formed by performing a surface treatment such as embossing, hairline processing, coloring processing, polishing processing, and painting processing on a molded product molded into a desired shape as described above. There are many, and simplification of manufacture is required.
Therefore, it is known to mold a molded article by blending a wood grain-forming pigment master batch composed of a base resin and a pigment with a wood-based material-containing polyolefin-based resin composition composed of a wood-based material and a polyolefin-based resin. (See Patent Document 1). In addition, as a base resin of the grain forming pigment masterbatch, a thermoplastic polyester elastomer having a melting point of 170 to 200 ° C and a melt flow rate of 1 to 50 g / 10 minutes is used. By molding in this way, the grain forming pigment masterbatch is in a semi-molten state at the time of molding and dispersed in a streak shape, thereby forming a grain pattern on the molded article.
[0003]
[Patent Document 1]
JP 2001-302808 A (pages 1 to 4)
[0004]
[Problems to be solved by the invention]
By the way, in order to make the wood-grain-forming pigment master batch in a semi-molten state at the time of molding and disperse it in a streak shape, the wood-grain-forming pigment must be melted and extruded in a temperature range at which the wood-based material-containing polyolefin-based resin composition is extruded. There is a need to melt thermoplastic polyester elastomers used as base resins for masterbatches. However, since selection of a resin as a thermoplastic polyester elastomer has not been established, depending on the selection of the resin, the wood-based material-containing polyolefin-based resin composition does not always melt at the temperature at which it is extruded, and the grain pattern is still reliable. Was difficult to form.
That is, for example, when a resin that melts at a temperature lower than the temperature at which the wood-based material-containing polyolefin-based resin composition is extruded is mixed with the wood-based material-containing polyolefin-based resin composition. No striped pattern is formed during extrusion molding. On the other hand, when a resin that melts at a temperature higher than the temperature at the time of extrusion is used, even if the wood-based material-containing polyolefin-based resin composition is melted, the resin does not melt, so that the resin is solidified during extrusion molding. Appear.
[0005]
The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a resin molded product and a method for manufacturing the resin molded product, which can surely form a striped grain pattern.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the invention of claim 1 is to mix and melt color pellets containing an acrylic resin and a pigment with a mixed material containing cellulose-based fine particles and a polyolefin-based resin, and extrude the mixture into a desired shape. It is characterized by becoming.
[0007]
According to the first aspect of the present invention, color pellets containing an acrylic resin and a pigment are mixed and melted in a mixed material containing cellulose-based fine particles and a polyolefin-based resin, and are extruded into a desired shape. In the temperature range in which the material melts, the color pellets containing the acrylic resin are extruded and flow while melting together with the mixed material, thereby forming a striped wood grain pattern. That is, since the acrylic resin has a wide melting temperature range, a striped wood pattern is formed by the acrylic resin that melts within the melting temperature range of the mixed material.
Therefore, unlike the conventional case, the base resin of the pigment is already melted and mixed before reaching the melting temperature of the mixed material, and there is no problem that the resin does not melt at the melting temperature, and the acrylic resin is used. By doing so, it is possible to reliably form a striped grain pattern, and it is also easy to control the temperature when the mixed material is melted.
In addition, as described above, by mixing and melting the color pellets with the mixed material and extruding, a striped grain pattern is formed at the same time as the extrusion molding. It is not necessary and leads to simplification of manufacturing.
[0008]
According to a second aspect of the present invention, in the resin molded product according to the first aspect,
The polyolefin resin is a polypropylene resin.
[0009]
According to the second aspect of the invention, the same effects as those of the first aspect can be obtained, but the polypropylene resin is suitable for the melting temperature condition with the acrylic resin, and also from the viewpoint of environmental protection. Excellent.
[0010]
According to a third aspect of the present invention, in the resin molded product according to the first or second aspect,
The cellulose-based fine particles are obtained from wood waste containing impurities.
[0011]
According to the third aspect of the present invention, the same effects as those of the first or second aspect can be obtained. In addition, since wood waste containing impurities is used, the viewpoint of effective use of resources and environmental protection. Also excellent from.
Examples of the wood waste materials include, for example, wood waste materials discharged when dismantling buildings such as houses, wood waste materials discharged when dismantling furniture, wood scraps discharged during building construction, sawdust and the like. No.
[0012]
The invention of claim 4 is the resin molded product according to any one of claims 1 to 3,
The mixed material contains a resin obtained from resin waste containing impurities.
[0013]
According to the fourth aspect of the invention, the same effect as any one of the first to third aspects can be obtained, and also, since the resin waste containing impurities is used, the resources are effectively used. And from the viewpoint of environmental protection.
Examples of the resin waste material include resin products used for containers and packaging of foods including beverages, other resin products, and further, resin waste materials discharged when dismantling buildings such as houses, and furniture. Resin waste materials and the like that are discharged when dismantled.
[0014]
The invention according to claim 5 is characterized in that color pellets containing an acrylic resin and a pigment are mixed and melted in a mixed material containing cellulose-based fine particles and a polyolefin-based resin and extruded into a desired shape.
[0015]
According to the fifth aspect of the present invention, a color pellet containing an acrylic resin and a pigment is mixed and melted with a mixed material containing cellulose-based fine particles and a polyolefin-based resin, and is extruded into a desired shape. In the melting temperature range, the color pellets containing the acrylic resin are extruded and flow together with the mixed material while melting, thereby forming a striped wood grain pattern. That is, by using an acrylic resin having a wide melting temperature range, it becomes possible to form a striped grain pattern more reliably than in the past, and it is also easy to control the temperature when melting the mixed material. Become.
In addition, a striped grain pattern is formed at the same time as the extrusion, which leads to simplification of production.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
The resin molded product according to the present invention is obtained by mixing and melting a color pellet containing an acrylic resin and a pigment with a mixed material containing cellulose fine powder and a polyolefin resin, and extruding the mixture into a desired shape. .
The cellulosic fine particles are obtained from wood waste containing impurities. Examples of the wood waste include, for example, wood waste discharged when dismantling buildings such as houses, wood waste discharged when dismantling furniture, wood scraps discharged during building construction, sawdust, and the like. No. Examples of the impurities include gypsum, a heat insulating material, and a resin member.
[0017]
Examples of the polyolefin-based resin include polypropylene, high-density polyethylene, low-density polyethylene, polybutene, polyisobrene, ethylene-vinyl acetate copolymer, and a mixture of at least two or more of these resins. Among them, it is particularly preferable to use polypropylene which is suitable for the melting temperature condition with the acrylic resin and which is excellent from the viewpoint of environmental protection.
[0018]
The mixed material containing the cellulose-based fine particles and the polyolefin-based resin may include a resin obtained from a resin waste containing impurities.
Resin waste materials include resin products used for containers and packaging of foods, including beverages, and other resin products, as well as resin waste materials that are discharged when dismantling buildings such as houses, and furniture. And resin waste material discharged when the cleaning is performed. Examples of the impurities include calcium carbonate for preventing expansion and contraction of the resin due to a change in temperature and the like, and talc used as a reinforcing material or a filler (for example, obtained by pulverizing hydrous magnesium silicate and firing it). ), Pigments, reinforced plastics (FRP) reinforced with glass fibers, and the like.
Examples of the resin constituting the resin waste material include polypropylene resin, hard or soft polyvinyl chloride resin, foamed polyvinyl chloride resin, polyethylene terephthalate resin, polystyrene resin, polyethylene resin, phenol resin, urethane resin, ABS resin, and the like. Can be
[0019]
On the other hand, the color pellets to be further mixed with the above-mentioned mixed material contain an acrylic resin and a pigment, and it is preferable to add an additive as needed.
As the pigment, for example, organic or inorganic dyes and pigments commonly used for coloring synthetic resins such as cadmium yellow, carbon black, iron oxide, titanium oxide, titanium yellow, and red iron can be used.
Examples of the additive include a dispersant, a fluid lubricant, a stabilizer and the like.
It is preferable that these acrylic resins, pigments, and additives are blended so as to be contained in the color pellets at a ratio of about 90%, 7%, and 3%, respectively.
[0020]
Next, a method for producing a resin molded product according to the present invention will be described.
First, in a pulverizing step, woody waste material is pulverized to obtain cellulosic fine particles. This pulverization step is formed from three stages of primary pulverization, secondary pulverization and tertiary pulverization. Needless to say, this pulverization mode is divided into each stage in order to efficiently perform the pulverization, and is not particularly limited to this. The pulverization can be performed by one type of pulverization process.
[0021]
The pulverizing device used in the primary pulverizing step has a pulverizing function capable of forming one lump into a large lump having a size of about several centimeters. This is a pulverizing device in which a number of protrusions are formed on the surface of an opposing roller, and the roller is rotated while applying pressure between the rollers, thereby crushing what passes between the rollers. Of course, the crushing device is not limited to this, and other crushing devices for coarse crushing may be used as long as they have the same function. For example, a jaw crusher that crushes a raw material by putting the raw material between a jaw and an oscillating jaw opened in an upward V-shape and a movable crushing surface that rotates in a fixed crushing surface to continuously crush the material. Other coarse pulverizers such as a rent crusher may be used.
[0022]
Next, in the secondary grinding step, the primary ground material after the primary grinding step is ground into a fine powder. The grinding device used in the secondary grinding process is capable of grinding a large lump to a size of several millimeters or less into a fine powder. And a hammer mill that repeats the crushing action until it passes through a round hole of a screen on the outer periphery of the hammer chip. Of course, the crushing device to be used is not limited to the above-mentioned hammer mill, and other crushing devices may be used as long as they have the same function. For example, a cutter mill that shreds with a cutter, a roll mill that crushes with a roller, or the like may be used.
[0023]
Next, in the tertiary pulverizing step, the secondary pulverized material after the secondary pulverizing step is pulverized into a fine powder. The crushing device used in the tertiary crushing step is capable of crushing the material obtained in the second crushing step into finer powders. Specifically, it is a so-called pin mill, which can perform fine pulverization by receiving an interaction of impact and repulsion by a pin attached to a disk. More specifically, the pin mill includes a disk-shaped rotating disk having a large number of pins in a vertical direction, and a fixed disk having a large number of pins on a surface facing the rotating disk, and is obtained by a secondary grinding step. When the material is put into the center of the rotating disk, it can enter the gap between the rotating disk and the pin attached to the fixed disk by centrifugal force, and can be pulverized into fine powder by the impact and repulsion interaction of the pin It is. In this tertiary grinding step, the above-mentioned pin mill is used to grind the particles into a size of about 60 μm. Of course, the pulverizing device is not limited to the above-described pin mill, but may be another fine pulverizing device having the same function, for example, a ball mill or a stone mill. In the above-mentioned pulverization step, the collected wood waste is divided into three stages and pulverized to obtain cellulose-based fine particles.
[0024]
On the other hand, the resin waste material is pulverized using, for example, a hammer mill or the like to obtain a pulverized resin powder.
Then, the cellulose fine powder and the resin pulverized powder obtained as described above and the polypropylene resin are mixed so as to be uniform to form a mixed material, and the compound is extruded by an extruder to form a compound. I do.
[0025]
In addition, an acrylic resin, a pigment, and an additive are mixed in advance, and the mixture is extruded from a perforated circular nozzle into a string shape and cut to produce a pellet-shaped color pellet.
[0026]
Next, the color pellets are put into the hopper of the extruder, extruded by a screw inside the extruder while being heated in a heating cylinder, and further extruded from a molding die to form a desired shape. Manufacture resin molded products. At this time, the acrylic resin in the color pellets starts to melt near the molding die and is extruded together with the melted compound. Therefore, when the color pellets flow during extrusion, a striped wood grain pattern is formed.
[0027]
In this molding step, the molding temperature is preferably set at about 160 to 220C, and more preferably in the range of 170 to 185C. When the molding temperature is set to 160 to 220 ° C., if the temperature is lower than 160 ° C., the softening of the polypropylene resin and the resin pulverized powder is insufficient and it is difficult to uniformly knead with the cellulosic fine particles. This causes changes such as carbonization.
Since the molding temperature is set to 160 to 220 ° C. in this manner, the cellulose fine powder obtained in the pulverizing step is not changed by heat in the molding step, and the polypropylene resin and the resin pulverized powder are sufficiently melted and softened. Thus, it can be uniformly kneaded with the cellulosic fine particles.
[0028]
As described above, according to the embodiment of the present invention, a color mixture containing an acrylic resin and a pigment is mixed and melted with a mixed material containing cellulose fine powder and a polyolefin resin, and is extruded into a desired shape. Therefore, in a temperature range in which the mixed material is melted, the color pellets containing the acrylic resin are extruded and flow while being melted together with the mixed material, thereby forming a striped grain pattern. That is, by using an acrylic resin having a wide melting temperature range, it becomes possible to form a striped grain pattern more reliably than in the past, and it is also easy to control the temperature when melting the mixed material. Become.
In addition, a striped grain pattern is formed at the same time as the extrusion, which leads to simplification of production.
Moreover, since woody waste materials and resin waste materials are used as raw materials for the cellulose-based fine particles and the resin pulverized powder, they are excellent from the viewpoint of effective use of resources and environmental protection.
[0029]
In the above-described embodiment, the cellulose-based fine particles are obtained from woody waste material containing impurities. However, the present invention is not limited to this. Cellulose-based fine particles are, for example, natural wood, bacas, and rice straw. It may be obtained by crushing a material.
[0030]
【The invention's effect】
According to the first and fifth aspects of the present invention, in a temperature range in which the mixed material is melted, the color pellets containing the acrylic resin are extruded and flow while being melted together with the mixed material to form a striped wood grain pattern. . That is, by using an acrylic resin having a wide melting temperature range, it is possible to reliably form a striped wood grain pattern, and it is also easy to control the temperature when melting the mixed material. In addition, a striped grain pattern is formed at the same time as the extrusion, which leads to simplification of production.
[0031]
According to the second aspect of the present invention, the polypropylene resin is suitable for the melting temperature condition of the acrylic resin, and is also superior from the viewpoint of environmental protection as compared with the conventionally used vinyl chloride resin.
[0032]
According to the third and fourth aspects of the present invention, it is excellent from the viewpoint of effective use of resources and environmental protection.

Claims (5)

A resin molded product obtained by mixing and melting color pellets containing an acrylic resin and a pigment with a mixed material containing cellulose-based fine particles and a polyolefin-based resin and extruding the mixture into a desired shape. The resin molded product according to claim 1,
A resin molded product, wherein the polyolefin resin is a polypropylene resin. The resin molded product according to claim 1 or 2,
A resin molded article characterized in that the cellulosic fine particles are obtained from wood waste containing impurities. The resin molded product according to any one of claims 1 to 3,
A resin molded product characterized in that the mixed material contains a resin obtained from a resin waste material containing impurities. A method for producing a resin molded product, comprising mixing and melting a color pellet containing an acrylic resin and a pigment with a mixed material containing cellulose-based fine particles and a polyolefin-based resin and extruding the mixture into a desired shape.