JP4339476B2 - Method for producing wood-grained thermoplastic composite resin molding - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a thermoplastic composite resin molded article having a wood texture and having a wood texture.
[0002]
[Prior art]
Conventionally, various attempts have been made to obtain a molded article having a wood texture by extruding a composite resin composition in which a plant-based filler such as wood powder is mixed with a thermoplastic resin. Since the body surface still has a high proportion of resin, the gloss peculiar to plastic remains, and it was practically difficult to easily obtain a molded body having a sufficient wood texture.
[0003]
Therefore, for example, on the surface of the wood synthetic board formed by the thermoplastic resin and the cellulosic filler, a grinding process is performed with a sander to form a large number of scratches, and then a colorant is applied to the surface, and finally There has been proposed a method of forming a pattern such as a grain similar to natural wood by printing a grain pattern (see Japanese Patent Laid-Open No. 9-216500).
[0004]
According to this method, the printing ink is impregnated in the wood powder on the surface and penetrates into the deep part of the flaws and the ink is smeared, so that a wood grain pattern with a wood texture can be obtained. Such an effect is certainly preferable.
However, this method includes a first grinding process for forming a large number of flaws, a colorant application process, a second grinding process that requires grinding and polishing while leaving a concave colored layer, and a process for printing a wood grain pattern on the polished surface. In order to actually employ industrially, it requires a variety of complex and large-scale equipment, and a method that can obtain a woody molded body with high productivity. It was hard to say.
[0005]
[Problems to be solved by the invention]
The present invention has been made in view of the above-mentioned problems in the conventional method for producing a composite resin molded body having a woody texture, and is derived from a plant-based filler, etc. It aims at providing the method which can manufacture a plastic composite resin molded object with high productivity.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 provides a resin composition A comprising a thermoplastic resin, a plant filler, and a pigment as a grooved molded article having grooves formed on the surface. After the extrusion molding, the surface including the groove of the grooved molded body is different from the pigment contained in the resin composition A in the resin composition A, and the matrix resin is the resin composition A. There is provided a method for producing a wood-grained thermoplastic composite resin molded article, which is formed by extrusion coating with a resin composition B further containing a masterbatch pigment different from the thermoplastic resin contained in .
[0007]
The invention described in claim 2 is a resin composition A in which a thermoplastic resin, a plant filler and a pigment are previously melt-kneaded and pelletized, and the resin composition A is added to the pelletized resin composition A. And a resin composition B containing a masterbatch pigment different in color from the pigment contained in the resin and having a matrix resin different from the thermoplastic resin contained in the resin composition A. A method for producing a wood-grain thermoplastic resin composite molded article according to claim 1.
In the invention of claim 3, the temperature at which the surface of the grooved molded body including the groove is extrusion-coated with the resin composition B is 10 times higher than the temperature at which the resin composition A is extruded into the grooved molded body. A method for producing a woodgrain thermoplastic composite resin molded article according to claim 1 or 2, wherein the temperature is lowered by -50 ° C.
[0008]
The invention according to claim 4 is the wood grain-shaped thermoplastic composite resin molded body according to any one of claims 1 to 3 , wherein the cross-sectional shape of the groove of the molded body is a substantially inverted triangle or a semi-circular shape. A manufacturing method is provided.
The invention according to claim 5 is characterized in that the content of the plant-based filler in the resin composition A is 50 to 80% by weight, and the grain of any one of claims 1 to 4 A method for producing a thermoplastic composite resin molded article is provided.
[0009]
Hereinafter, the present invention will be described in more detail.
As the thermoplastic resin used in the composite resin composition in the present invention, polyolefin such as polyethylene and polypropylene, polyamide, polyacetal, polyethylene terephthalate, polybutylene terephthalate, fluororesin, polyphenylene sulfide, polystyrene, ABS, acrylic resin, Commercially available thermoplastic resins such as polycarbonate, polyurethane, polyvinyl chloride, polyphenylene oxide, and ethylene-vinyl acetate copolymer may be mentioned. In particular, from the viewpoint of cost and the like, polyolefin resins such as polyethylene and polypropylene are preferable.
[0010]
The plant-based filler used in the present invention is not particularly limited as long as the obtained molded product has a plant-like appearance and gives a soft feel, and is a filler made of plants. . For example, cutting waste such as timber, wood board, plywood, pulp, bamboo, etc., abrasive waste, cutting sawdust, wood powder such as pulverized product; grain or fruit shell such as rice husk and walnut shell or pulverized product thereof .
[0011]
The content of the plant filler is preferably 50 to 80% by weight in the resin composition A. If the amount is less than 50% by weight, the wood texture is lowered, and if it is more than 80% by weight, the dispersibility in the resin composition A starts to deteriorate, and the physical properties may be lowered.
The particle size of the plant-based filler can usually be 1 to 1000 μm, preferably 10 to 300 μm. When it is smaller than 1 μm, it is difficult to uniformly disperse, and when it is larger than 1000 μm, the grains are conspicuous and the woody tone is lowered.
[0012]
As the pigment in the present invention, a colored pigment is used, and examples thereof include inorganic pigments such as iron oxide, carbon black, and titanium oxide, or organic pigments. A commercially available product can be used without any particular limitation, but a pellet-like masterbatch is easy to use in terms of easy handling and control of the dispersion state. If necessary, it may be added to and contained in both the resin composition A and the resin composition B.
In the present invention, when the surface including the groove of the grooved molded body is formed by extrusion coating with the resin composition B, the colored pigment is non-uniformly dispersed in the resin composition B. It is necessary to make the coated layer exhibit a wood grain.
[0013]
In order to prevent the pigment of different colors from being dispersed uniformly in the resin composition B and prevent the coating layer from exhibiting the same color uniformly, it is convenient to use, for example, a master batch pigment, and if necessary, the resin composition A may be contained in A. In the present invention, the master batch pigment is a mixture of a different color pigment in a thermoplastic resin at a high concentration, and is formed into pellets or strips. Hereinafter, this may be simply referred to as “master batch”.
[0014]
Specifically, what is necessary is just to change affinity, melt viscosity, melting temperature, etc. of the thermoplastic resin used for the said resin composition B, and the resin used for a masterbatch.
In order to change the affinity, a combination of resin types that are difficult to mix during melting is used.
The melt viscosity is set so that the viscosity of the resin used in the masterbatch is higher or lower than the melt viscosity of the thermoplastic resin used in the resin composition B.
The melting temperature is set so that the temperature of the resin used in the master batch is higher or lower than the melting temperature of the thermoplastic resin used in the resin composition B.
[0015]
In addition, the resin composition A or B includes a reinforcing material such as glass fiber or carbon fiber, or a plasticizer for improving moldability (αβ unsaturated carboxylic acid monomer, low molecular olefin, etc.) as necessary. Additives such as lubricants (stearic acid, stearic acid metal salts, etc.), UV absorbers for improving durability such as weather resistance, UV degradation inhibitors, and oxidation degradation inhibitors can be blended.
[0016]
In the present invention, the resin compositions A and B are heated and kneaded and extrusion-molded by the following method, for example.
1. A resin composition A containing a thermoplastic resin and a plant-based filler is directly charged into an extruder and extruded while being heat-kneaded.
2. After heat-kneading with an extruder and producing pellets once, extrusion molding is performed using the obtained pellets.
3. The mixture is heated and kneaded in a batch facility such as a super mixer to produce pellets, which are then extruded.
[0017]
When extruding, the extruder can be used from general extruders such as commercially available uniaxial, co-directional biaxial, and bi-directional biaxial to special extruders such as planetary screw extruders and KCK containment mixers. is there.
In the above method 1, it is preferable to use an extruder having a great kneading effect such as a twin-screw kneading extruder. In the above method 2 or 3 in which the compound is pelletized in advance, it is preferable to use an ordinary extruder such as a single screw or a twin screw.
[0018]
When trying to disperse the above-mentioned different color pigment in the resin composition B non-uniformly, the extrusion molding of the groove part is performed by using a single extruder having a small diameter for the thermoplastic composite material pelletized in advance and the different color pigment master batch. The extrusion method is simple.
The temperature at which the surface including the groove of the grooved molded body is extrusion-coated with the resin composition B is 10 to 50 ° C. higher than the temperature at which the resin composition A is extruded into the grooved molded body. Even by lowering, it is possible to easily achieve non-uniform dispersion.
However, if the temperature cannot be lower than 10 ° C., the colored state becomes uniform, and if it is lower than 50 ° C., extrusion molding becomes difficult.
Furthermore, a master batch in which a different color pigment is blended is more effective if the material itself is difficult to mix as described above.
[0019]
When the cross-sectional shape of the groove is substantially rectangular, the flow velocity distribution is relatively constant in the groove, so that a straight wood grain (a grid) is developed.
As described in claim 4, when the cross-sectional shape of the groove is a substantially inverted triangle or semicircular shape, the flow velocity distribution becomes large at the center and at the end, the different color pigment remains as a flow mark, and the grain like a grain To express. The groove shape can be selected according to the required design.
[0020]
(Function)
In the present invention, a resin composition A containing a plant-based filler and a pigment is extruded into a molded article with grooves, and then the surface containing the grooves is contained in the resin composition A and contained in the resin composition A. When the resin composition B is different in color from the pigment and the matrix resin further contains a masterbatch pigment different from the thermoplastic resin contained in the resin composition A, it is extrusion coated with a different color. pigment Ri Do to be extrusion coated shaped to unevenly distributed in the resin composition B, because there is no unique pigment moiety will apparently be the first to extruded fluted moldings same color uniform The surface of the groove containing the different color pigments allowed the appearance of uneven, random grain that appeared, disappeared, or fluctuated.
[0021]
The invention described in claim 2 enables a relatively simple method among the methods described in claim 1 by previously pelletizing the raw material.
The invention according to claim 3 is also claimed by setting the temperature at which the grooved molded body surface is extrusion-coated with the resin composition B to be 10 to 50 ° C. lower than the extrusion temperature of the resin composition A. In the method for producing a wood-grained thermoplastic composite resin article according to Item 1, a relatively simple method is made possible.
In the invention according to claim 4, the cross-sectional shape of the groove is a shape in which the flow velocity distribution is likely to be generated, so that the discolored pigment is dispersed non-uniformly and the flow pattern is disturbed to express the grain shape. I made it.
Moreover, by making content of a plant-type filler into 50 to 80 weight% in the resin composition A, a wood texture can be provided reliably.
DETAILED DESCRIPTION OF THE INVENTION
[0022]
FIG. 1 is a schematic side view showing an embodiment of an extrusion apparatus suitable for use in the practice of the present invention. An extruder 1 such as a biaxial co-directional extruder is an extruder for forming a grooved molded body having grooves formed on the surface thereof, and a grooving shaping mold 2 is provided on the downstream side thereof. .
[0023]
The grooved shaping mold 2 is connected to a groove filling mold 3 of a cross head that is used when the surface of the grooved molded body including the groove is extrusion coated with the resin composition B. 3 is provided with an extruder 4 for extruding the resin composition B, and is provided with a cooling die 5 for cooling the grooved molded body in the middle of molding, and an extrusion molding apparatus 6 is configured. Thus, a wood-grained thermoplastic composite resin molding 7 is manufactured from the resin composition A supplied to the extruder 1 and the resin composition B supplied to the extruder 4.
[0024]
Note that the thermoplastic composite resin molded body 7 is usually formed by filling and coating the resin composition B only on the groove 8 as shown in FIG. 9. However, as shown in FIG. The other surface may be covered with the resin composition B.
Moreover, as described above, the cross-sectional shape of the groove is not limited to a substantially rectangular shape as shown in FIG. 8, but may be a substantially inverted triangle or a semicircular shape.
[0025]
(Example 1)
100 parts by weight of homopolypropylene (Novatech MA3, manufactured by Nippon Polychemical Co., Ltd.) as a thermoplastic resin, 200 parts by weight of wood flour (Cellulosin No45, manufactured by Watanabe Chemical Co., average particle size: 100 μm) as a plant-based filler, improve moldability Therefore, 5 parts by weight of stearic acid as a lubricant and 5 parts by weight of Sumika Color SPPM9A1056 (matrix resin is a master batch of polypropylene, color: yellow) as a pigment are dry blended, and a twin-screw kneading extruder PCM30 (manufactured by Ikegai Co., Ltd.) The barrel temperature was all 180 ° C., kneaded and extruded, and pelletized.
[0026]
While putting only the obtained pellets into the hopper of the extruder (Hitachi Shipbuilding SL50) 1 shown in FIG. 1 and extruding the grooved molded body 21 having grooves formed on the surface from the grooved shaping mold 2, Into Extruder 4 (extruder for groove filling molding, VS30 manufactured by Ikegai Co., Ltd.), 100 parts by weight of the above pellets are charged at a ratio of 1 part of different color pigment (Suika Color SPEM9E052, matrix resin polyethylene, color: brown), and cross Through the groove filling mold 3 and the cooling shaping mold 5 of the head, a wood grain-like thermoplastic composite resin molding 7 was obtained.
[0027]
In addition, the molding temperature of the extruders 1 and 4 was set to 190 ° C., and the mixture was sufficiently heated and kneaded at a resin temperature of 190 ° C. The shape and dimensions of the grooved molded body 21 are as shown in FIG. 2, and the grooved shaping mold 2 having a shape corresponding to this is heated to 180 ° C. together with the groove filling mold 3, and the cooling mold is supplied with cooling circulating water. And set to 90 ° C. The cross-sectional shape of the obtained thermoplastic composite resin molding 7 was as shown in FIG.
[0028]
The surface state of the sample obtained by the above production was as shown in FIG.
In this example, the resin composition A containing polypropylene and wood flour is used to form the groove by using the resin composition B containing a different color pigment masterbatch whose matrix resin is polyethylene. In the resin composition B, the pigments of different colors are dispersed non-uniformly.
[0029]
(Example 2)
A thermoplastic composite resin molded body 7 was obtained in the same manner as in Example 1 except that the barrel temperature of the groove filling extruder 4 was 150 ° C. and the resin temperature of the cross head groove filling mold 3 was 160 ° C. The surface state of the obtained sample was as shown in FIG.
[0030]
(Example 3)
A thermoplastic composite resin molded body 7 was obtained in the same manner as in Example 1 except that the grooved shaping mold 2 in which the shape and size of the grooved molded body 22 was as shown in FIG. 3 was used. The surface state of the obtained sample was as shown in FIG.
[0031]
(Example 4)
In Example 1, a thermoplastic composite resin molded body 7 was obtained in the same manner except that 30 parts by weight of wood flour (Cellulosin No45, manufactured by Watanabe Chemical Co., Ltd., average particle size 100 μm) was used as the plant-based filler. The surface state of the obtained sample is as shown in FIG. 7, and from Example 1, the surface was a plastic film.
[0032]
(Comparative Example 1)
In Example 1, a thermoplastic composite resin molded article was similarly produced except that Sumika Color Brown SIMB9A (matrix resin: polypropylene, color: brown) was used as the different color pigment to be fed into the groove filling extruder 4. Obtained. As shown in FIG. 8, the surface state of the obtained sample was that the pigment in the resin composition in the groove was uniformly dispersed and did not exhibit a wood grain tone.
[0033]
(Comparative Example 2)
In Example 1, as a different color pigment charged into the groove filling extruder 4, Sumika Color Brown SIMB9A (matrix resin: polypropylene, color: brown) was used except that the barrel temperature was 120 ° C. An attempt was made to produce a wood-grain thermoplastic composite resin molded product, but during the course of the process, extrusion molding became difficult due to an increase in back pressure, and no sample was obtained.
[0034]
【The invention's effect】
The method for producing a woodgrain thermoplastic composite resin molded article of the present invention is configured as described above. The surface including the groove of the grooved molded article is applied to the resin composition A, and the resin composition A is applied to the resin composition A. Extrusion-coating with a resin composition B, which is different in color from the contained pigment and in which the matrix resin further contains a masterbatch pigment different from the thermoplastic resin contained in the resin composition A in, Ri can Do to the pigment of different colors are extrusion coated shaped to unevenly distributed in the resin composition B, and the surface containing the groove, thermoplastic composite with random grain with such fluctuations in uneven A resin molded body can be provided.
[0035]
The invention described in claim 2 enables a relatively simple method among the methods described in claim 1 by previously pelletizing the raw material.
The invention according to claim 3 is also claimed by setting the temperature at which the grooved molded body surface is extrusion-coated with the resin composition B to be 10 to 50 ° C. lower than the extrusion temperature of the resin composition A. In the method for producing a wood-grained thermoplastic composite resin article according to Item 1, a relatively simple method is made possible.
In the invention according to claim 4, the cross-sectional shape of the groove is made into a shape in which a flow velocity distribution is likely to be generated, so that the discolored pigment is unevenly dispersed and the flow pattern is disturbed, thereby comprising a random and non-linear grain. The grain pattern can be expressed.
Moreover, the invention of Claim 5 can give a wood texture reliably by making content of a plant-type filler into 50 to 80 weight% in the resin composition A. FIG.
[Brief description of the drawings]
FIG. 1 is a schematic side view showing an embodiment of an extrusion apparatus suitable for use in the practice of the present invention according to claim 1;
FIG. 2 is a side view showing the dimensional shape of a grooved molded body obtained in Examples 1, 2, and 4. FIG.
3 is a side view showing the dimensional shape of a grooved molded body obtained in Example 3. FIG.
FIG. 4 is a schematic plan view of a woodgrain thermoplastic composite resin molded body sample obtained in Example 1;
5 is a schematic plan view of a woodgrain thermoplastic composite resin molded body sample obtained in Example 2. FIG.
6 is a schematic plan view of a woodgrain-type thermoplastic composite resin molded body sample obtained in Example 3. FIG.
7 is a schematic plan view of a woodgrain thermoplastic composite resin molded body sample obtained in Example 4. FIG.
8 is a schematic plan view of an extruded product sample obtained in Comparative Example 1. FIG.
FIG. 9 is a schematic cross-sectional view showing one embodiment of a wood-grain thermoplastic composite resin molding obtained by the present invention.
FIG. 10 is a schematic cross-sectional view showing another embodiment of a wood-grain thermoplastic composite resin molding obtained by the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Extruder 2 Grooving shaping type | mold 3 Groove filling type | mold 3 Cooling shaping type | mold 4 Extruder 5 Cooling type | mold 6 Extrusion molding device 7 Grain-like thermoplastic composite resin molding 8 Groove 21 Grooving molding 22 Grooving molding

Claims (5)

A resin composition A containing a thermoplastic resin, a plant filler and a pigment is extruded into a grooved molded body having grooves formed on the surface, and then the surface including the grooves of the grooved molded body is formed. Further, a master batch pigment having a different color from the pigment contained in the resin composition A and a different matrix resin from the thermoplastic resin contained in the resin composition A is further added to the resin composition A. A method for producing a wood-grained thermoplastic composite resin molded article, which is formed by extrusion coating with a resin composition B to be contained . The resin composition A in which a thermoplastic resin, a plant filler and a pigment are previously melt-kneaded and pelletized, and the pigment contained in the resin composition A in the pelletized resin composition A has a color. The wood grain-like resin composition according to claim 1, wherein the resin composition B is different from the thermoplastic resin contained in the resin composition A and contains a masterbatch pigment different from the thermoplastic resin . A method for producing a thermoplastic resin composite molded body.   The temperature at which the surface including the groove of the grooved molded body is extrusion-coated with the resin composition B is 10 to 50 ° C. lower than the temperature at which the resin composition A is extruded into the grooved molded body. A method for producing a woodgrain thermoplastic composite resin molded article according to claim 1 or 2. The cross-sectional shape of the groove of the molded body, method for producing a thermoplastic composite resin molded article of wood of any one of claims 1 to 3, characterized in that a substantially inverted triangular or substantially semicircular. 5. The method for producing a wood-grain thermoplastic composite resin molded article according to claim 1 , wherein the content of the plant filler in the resin composition A is 50 to 80% by weight. .

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