JP4956379B2 - Bioplastics and bioplastic moldings - Google Patents

Description

  The present invention relates to a bioplastic obtained by mixing a wood-based material and a resin material, and a bioplastic molded article using the bioplastic.

For example, the switchboard includes a vertical box elongated in the height direction, and a plurality of unit chambers are provided in the vertical box side by side in the height direction. A unit for controlling the electric motor is placed in each unit chamber, and a door is rotatably provided on the front surface of each unit chamber.
The door is formed with an opening so that the unit placed in the unit chamber can be operated even when the door is closed (see, for example, Patent Document 1).
JP 2006-289835 A

  When the number of units to be used is smaller than the number of units in the unit room, the opening of the door of the unit room that does not store the unit is closed with a closing member (molded product). This is to prevent foreign matter that reaches the vertical bus bar from entering the unit chamber.

  The closing member includes a plate-like lid portion (substrate portion) that closes the front surface of the opening, and an engagement claw portion that protrudes from a surface of the lid located on the opening side. It is a molded product. Then, when the engaging claw portion of the closing member is inserted into the opening portion, the front end portion of the engaging claw portion abuts against the front surface side of the opening edge portion of the door, so that it is opposite to the opening edge portion. (Elastically deformed). When the engaging claw is continuously inserted into the opening, the tip of the engaging claw is detached from the front side of the opening edge, and the engaging claw is caught on the back side of the opening edge of the door. .

  Here, an inexpensive and easily deformable petroleum-based resin (for example, ABS resin) is used as the material of the closing member. When the closing member attached to the door becomes unnecessary due to the expansion of the unit or the like, the closing member is removed from the door and generally incinerated. However, such treatment increases the amount of carbon dioxide emission, and has a serious environmental impact such as air pollution.

To cope with this, recently, bioplastics (not including pure biodegradable plastics) made by mixing woody materials and resinous materials instead of petroleum-based resins are used, and the inclusion of woody materials It is considered to reduce the amount of petroleum-based resin corresponding to the amount, and this makes it possible to reduce the generation of carbon dioxide when the closing member is incinerated.
For this reason, it is desired to increase the amount of the wood-based material contained in the bioplastic, but in this case, the blocking member increases in hardness, becomes difficult to deform, and becomes brittle. Therefore, there is a possibility that the engaging claw portion is damaged when the engaging claw portion is deformed when the closing member is attached to the opening of the door.

  This invention is made | formed in view of said situation, The objective is to provide the bioplastic excellent in impact resistance and rigidity, and a bioplastic molded article using the same.

The bioplastic of the present invention is obtained by mixing 60 % by mass of a woody material, 20 to 30% by mass of polypropylene as a resin material, and 20 to 10% by mass of polyethylene as an impact resistance improver. It is characterized (invention of claim 1).
The bioplastic molded article according to the present invention includes a substrate portion that is located on one surface of a substrate on which an opening is formed and closes the opening, and an engaging claw that protrudes from a surface located on the opening portion side of the substrate portion and a section, wherein the substrate portion and the engaging claw portion is integral that is molded is characterized in (the invention of claim 2) bioplastic according to claim 1.

According to bioplastic present invention, 60 mass% of the wood-based material, 20-30 and polypropylene as the mass% of the resin material, by mixing a polyethylene as an impact improver of 20 to 10 wt% Configuration Therefore, compared to materials consisting only of petroleum-based resins that do not contain wood-based materials, the amount of petroleum-based resins used can be reduced by the amount corresponding to the content of wood-based materials, and the amount of carbon dioxide when incinerated Generation | occurrence | production can be decreased and there exists an effect that it is excellent in impact resistance and rigidity.

  The bioplastic molded product of the present invention can be prevented from being damaged when the engaging claw is elastically deformed.

Hereinafter, an embodiment in which the present invention is applied to a switchboard door will be described with reference to the drawings.
As shown in FIG. 2, the switchboard 1 includes a vertical box 2 that is long in the height direction. In the vertical box 2, a horizontal wiring processing chamber 3, a plurality of unit chambers 4, and the like are arranged in the height direction. In addition, the vertical wiring processing chamber 5 extending in the vertical direction is divided and configured. A unit 6 for controlling an electric motor (not shown) is placed in the unit chamber 4.

  The unit 6 has a cylindrical dial 7 projecting forward, and a knob portion 8 is formed at the tip of the dial 7. The dial 7 is a rotary operation dial for a circuit breaker. The dial 7 is rotated to switch the circuit breaker between “ON”, “OFF”, and “TRIP”. Next to the dial 7 of the unit 6, there are provided an operation unit 9 including a switch key group of a multi-motor relay for controlling the electric motor and a display unit 10 indicating an operation state of the electric motor and the like.

  A door 11 as a substrate is rotatably provided on the front surface of each unit chamber 4. The door 11 is manufactured by processing a metal plate. As shown in FIG. 3, the door body 12 located on the front surface of the unit chamber 4 is formed in a rectangular shape, as shown in FIGS. 2 to 7. Moreover, the outer peripheral edge 13 of the door 11 is bent backward. In addition, an annular opening 14 that is slightly larger than the dial 7 is formed in a portion of the door body 12 corresponding to the dial 7 of the unit 6 accommodated in the unit chamber 4. A portion corresponding to the portion 10 is formed with a rectangular opening 15 that integrally surrounds the operation portion 9 and the display portion 10. Then, when the door 11 is closed in a state where the unit 6 is stored in the unit chamber 4 (see, for example, the unit chamber 4 positioned at the lowest level in FIG. 2), the knob portion 8 of the unit 6 opens the opening 14 of the door 11. It is comprised so that it may protrude from. The operation unit 9 and the display unit 10 of the unit 6 are configured not to protrude from the opening 15 of the door 11. Thereby, even when the door 11 is closed, the knob portion 8 and the operation portion 9 are possible, and the display portion 10 can be seen.

As shown in FIG. 3, holes 16 and 16 are formed on the outer peripheral side of the opening 14 of the door body 12. The holes 16 and 16 are formed at symmetrical positions around the opening 14.
As shown in FIG. 2, a rectangular frame-shaped decorative frame 17 is provided on the periphery of the opening 14 of the door 11. A hole 18 through which the dial 7 and the knob 8 are inserted is formed in the center of the decorative frame 17. A portion of the decorative frame 17 corresponding to the hole portions 16 and 16 is formed with a hole portion (not shown), and the decorative frame 17 is configured so that the hole portion and the hole portions 16 and 16 coincide with each other. 12 is attached with screws 19 and 19. Although not shown in the drawing, indications such as “ON”, “TRIP”, “OFF”, and “RESET” are attached around the hole portion 18 of the decorative frame 17 corresponding to the stop position of the knob portion 8. ing.

  Here, the door 11 of the unit chamber 4 in which the unit 6 is not accommodated (for example, refer to the fourth to sixth steps from the upper level of the unit chamber 4 in FIG. 2), the opening 14 and the opening of the door 11. Closing members 21 and 22 for closing 15 are attached.

  As shown in FIGS. 4 to 7, the closing member 21 is positioned on the front surface of the door 11 and has a rectangular plate-like lid portion 23 that closes the opening portion 14 and the holes 16 and 16 of the door 11, and the lid portion 23. An engaging claw portion 24 that protrudes rearward from the surface located on the opening portion 14 side through the opening portion 14 is configured. The engaging claw portions 24 are formed at a plurality of locations on the opening edge portion 14 a of the door 11, for example, at two locations on a horizontal line passing through the center of the door 11. Each engaging claw portion 24 has a shape with a pointed tip, and has an inclined surface 24 a that approaches the inner peripheral side of the opening 14 toward the tip.

  Further, on the surface of the lid portion 23 located on the hole 16 (opening 14) side, the portion corresponding to the holes 16 and 16 has a positioning convex portion 25 protruding rearward through the holes 16 and 16. 25 is formed. The positioning projections 25 and 25 have a slit and can be reduced in diameter, and are inserted into the holes 16 and 16 of the door 11 in a press-fitted state.

The closing member 22 is located on the front surface of the door 11 and has a rectangular plate-like lid portion 26 that closes the opening portion 15 of the door 11, and a surface located on the opening portion 15 side of the lid portion 26 through the opening portion 15. And an engaging claw portion that protrudes rearward, for example, an engaging claw portion 27. The engaging claw portions 27 are formed at a total of four locations in the center of the upper, lower, left and right sides of the opening 15 of the door 11. Each engagement claw portion 27 has a shape with a sharp tip, and has an inclined surface 27 a that approaches the inner peripheral side of the opening 15 toward the tip.
In the present embodiment, the closing members 21 and 22 are bioplastic molded products integrally formed of bioplastic described later, and the lid portions 23 and 26 are substrate portions.

Next, the structure which attaches the closure members 21 and 22 to the door 11 is demonstrated with reference to FIG.6 and FIG.7.
First, a configuration in which the closing member 21 is attached to the opening 14 of the door 11 will be described. When the engaging claw portion 24 of the closing member 21 is inserted into the opening portion 14 while the positioning convex portions 25 and 25 of the closing member 21 are aligned with the hole portions 16 and 16 of the door 11, the engaging claw portion 24 is formed at the tip portion. The formed inclined surface 24a comes into contact with the front surface side of the opening edge 14a, and warps in the opposite direction (elastically deforms) with respect to the opening edge 14a. When the engaging claw portion 24 is continuously inserted into the opening portion 14, the inclined surface 24a is detached from the front surface side of the opening edge portion 14a, and the engaging claw portion 24 is caught on the back side of the opening edge portion 14a of the door 11, Accordingly, the closing member 21 is attached to the opening 14 of the door 11.

  Next, a configuration in which the closing member 22 is attached to the opening 15 of the door 11 will be described. When the engaging claw portion 27 is inserted into the opening portion 15 so that each engaging claw portion 27 of the closing member 22 and the opening portion edge portion 15a coincide with each other, the engaging claw portion 27 is inclined at the tip portion. When the surface 27a abuts on the front surface side of the opening edge 15a, the surface 27a warps in the opposite direction to the opening edge 15a (is elastically deformed). When the engaging claw 27 is continuously inserted into the opening 15, the inclined surface 27a is detached from the front side of the opening edge 15a, and the engaging claw 27 is caught on the back side of the opening edge 15a of the door 11, Accordingly, the closing member 22 is attached to the opening 15 of the door 11.

Here, the closing members 21 and 22 are formed of a bioplastic obtained by mixing a wood-based material and a resin material.
Examples of the wood-based material include wood powder, wood fiber, wood piece, plant fiber, other lignocellulosic material mainly composed of cellulose and lignin, and those obtained by pulverizing cellulose powder and pulp. I use powder.

As the resin material, there is a polyolefin-based resin, and in this embodiment, polypropylene is used.
As the impact resistance improver, polyethylene, for example, linear low density polyethylene is used.
Then, the above wood-based material, resin material and impact resistance improver are heat-kneaded (mixed) at a high temperature, for example, 160 ° C. to 180 ° C. for 10 seconds to 30 minutes, using an unillustrated kneader, injection molded, The closing members 21 and 22 made of bioplastic are manufactured.

  Now, in order to confirm the impact resistance, ease of cracking, and rigidity of the bioplastic produced as described above, the inventors of the compositional components shown in FIG. A sample was obtained. In addition, as shown below (in order to be environmentally friendly), there is a demand to include as much wood-based material as possible. Therefore, as a bioplastic, it is good to occupy 50 mass% or more of the whole ratio with a wood-type material. However, when the ratio of the wood-based material exceeds 70% by mass, the fluidity is deteriorated and the molding cannot be performed by injection molding or the like. Therefore, it is preferable to mix 50 to 70% by mass of a wood-based material with a total of 50 to 30% by mass of a resin material and an impact resistance improver. Further, a material obtained by mixing 60% by mass of a wood-based material with a total of 40% by mass of a resin material and an impact resistance improver is more preferable. In the following experiment, the wood-based material was used at 60% by mass.

  The impact resistance of each sample formed as described above was first measured. For the impact resistance, the Charpy impact value was measured according to the Charpy impact test method described in “JIS K7111”. The Charpy impact value is a value obtained by dividing the energy required for breaking the sample by the cross-sectional area before breaking the sample. The higher this value, the better the toughness and the harder it is to break. In FIG. 1, the Charpy impact values of the experimental examples 1 to 5 relative to the Charpy impact value of the sample of the comparative example were relatively evaluated. That is, the Charpy impact values of the experimental examples 1 to 5 are indicated by the rate of change (%) when the Charpy impact value of the sample of the comparative example is 100%. In addition, the samples of Experimental Examples 1 to 5 and Comparative Example use a test piece cut to a predetermined size, and the impact resistance is divided into two types, a case where a notch is formed on the test piece and a case where a notch is not formed. Was confirmed. In this experiment, the test piece is set to a length of 80 mm, a width of 10 mm, and a thickness of 4 mm.

  Further, when the actual molded product (the closing members 21 and 22) is molded with the composition shown in FIG. 1 and these molded products are attached to the door 11, it is difficult to break the engaging claws 24 and 27 of the molded product. Was confirmed. In FIG. 1, when the molded product is attached to the door 11, “o” indicates that the engaging claws 24 and 27 are not broken, and “x” indicates that the molded claw is not broken.

  Further, an actual molded product (blocking members 21 and 22) is molded with the composition components shown in FIG. 1, and these molded products are heated to a temperature higher than the use environment temperature at which the blocking members 21 and 22 are actually used, for example, In the test, it was heated to 70 ° C., and the rigidity of the molded product (difficult to bend and deform) when it was attached to the door 11 was confirmed. In FIG. 1, when the molded product is attached to the door 11, when the entire molded product is not deformed (when the rigidity is excellent), it is indicated by “◯”, and when it is deformed, it is indicated by “x”.

  From the results of the Charpy impact test, first, Experimental Examples 1 to 5 containing 5 to 25% by mass of the impact resistance improver have a higher rate of change than the sample of the comparative example not containing the impact resistance improver, and impact resistance. That is, it can be understood that the toughness is excellent. In addition, it can be judged that the same toughness characteristic is seen in the two types of experiments with and without the notch, and there is reproducibility.

  From the result of confirming the ease of cracking of the engaging claws 24 and 27 of the molded product when the molded product is attached to the door 11, the resin material is contained in an amount of 15 to 30% by mass, and the impact resistance improver is contained in an amount of 25 to 10% by mass. Since the molded articles of Experimental Examples 2 to 5 that were included were not cracked when attached to the door 11, it can be understood that they are practical.

  From the result of confirmation of rigidity when the molded product is heated to 70 ° C. and the molded product is attached to the door 11, the resin material is contained in an amount of 20% by mass or more, and the content of the impact resistance improver is 20% by mass or less. Since the samples of Experimental Examples 1 to 4 and Comparative Example were not deformed when attached to the door 11, it can be understood that they are practical.

  According to the above configuration, when the bioplastic is configured by mixing 50 to 70% by mass of a woody material, and a total of 50 to 30% by mass of a resin material and an impact resistance improver, the petroleum-based material does not contain a woody material. Compared to a material made of resin alone, the amount of petroleum resin used can be reduced by the amount corresponding to the content of the woody material, and impact resistance and rigidity can be obtained. In particular, bioplastics with a wood-based material of 60% by mass, a resin material of 20-30% by mass of polypropylene, and an impact resistance improver of 20-10% by mass of polyethylene have better impact resistance and rigidity. Played and practical.

Since the closing members 21 and 22 have the lid portions 23 and 26 and the engaging claw portions 24 and 27, the lid portions 23 and 26 can block the openings 14 and 15 formed in the door 11. The closing members 21 and 22 can be held on the door 11 by the engaging claw portions 24 and 27. Since the closing members 21 and 22 are made of the above-described bioplastic, it is possible to obtain a member having excellent impact resistance and rigidity, and to prevent the engaging claws 24 and 27 from being damaged during elastic deformation as much as possible. can do.
Since the positioning convex portions 25 and 25 are formed in the portions corresponding to the hole portions 16 and 16 on the surface located on the door 11 side of the lid portion 23, by aligning the positioning convex portions 25 and 25 with the hole portions 16 and 16. The positioning of the door 11 and the closing member 21 can be facilitated.

The present invention is not limited to the embodiment described above and shown in the drawings, and the following modifications and expansions are possible.
The blocking member 21 may have a shape connected to the blocking member 22.
In the present embodiment, the present invention is applied to a switchboard door, but the present invention can be applied as long as a closing member is provided on a substrate on which an opening is formed. Further, the substrate material can be applied to other than the metal.
In addition, the number, shape, position, and the like of the above-described components can be changed as appropriate.

The figure which shows the relationship between the composition component of bioplastic which shows one Embodiment of this invention, and material property Switchboard perspective view Front view of the door Front view showing a state in which the closing member is attached to the door 4 shows the door and closing member in FIG. 4 rotated 180 degrees about a horizontal line passing through the center of the door. Sectional drawing which follows the AA line in FIG. The figure which shows the state before attaching a closure member to a door

Explanation of symbols

  In the drawings, 1 is a switchboard, 11 is a door (substrate), 14 and 15 are openings, 14a and 15a are edges of openings, 21 and 22 are closing members, 23 and 26 are lids (substrate), 24 and Reference numeral 27 denotes an engaging claw portion.

Claims (3)

A bioplastic obtained by mixing 60 % by mass of a woody material, 20 to 30% by mass of polypropylene as a resin material, and 20 to 10% by mass of polyethylene as an impact resistance improver. A substrate portion that is located on one surface of the substrate on which the opening is formed and closes the opening; and an engagement claw portion that protrudes from a surface located on the opening side of the substrate portion,
The substrate portion and the engaging claw portion, it features a to Luba Io plastic molded article which is integrally molded with bioplastics according to claim 1. The bioplastic molded product according to claim 2, wherein the substrate is a door of a switchboard .

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