JP2021192979A - Cnf container, tubular body, and manufacturing of tubular body - Google Patents

Abstract

To provide a CNF container capable of obtaining a highly strong tubular body or the like by using a sheet-like member containing CNF.SOLUTION: A CNF container has, at least on a part, a laminate structure integrated by laminating sheet-like members containing CNF.SELECTED DRAWING: Figure 2

Description

The present invention relates to a CNF-containing body containing CNF, a tubular body that can be used for a winding core, and a method for producing the tubular body.

In recent years, research and development on the use of cellulose nanofibers (hereinafter, may be referred to as "CNF") as a material having excellent strength and gas barrier properties have been promoted. CNF is made by unraveling plant fibers obtained from wood and the like and refining them to the nano-order, and since it is derived from plant fibers, the environmental load associated with production and disposal is small. Moreover, CNF is light and strong, does not easily expand thermally, and has excellent gas barrier properties, and is expected to be used for various purposes.

Patent Document 1 discloses an example of a method for producing a sheet (cellulose nanofiber sheet) containing CNF. Further, Patent Document 2 discloses a technique for controlling the orientation of CNF contained in a sheet. As the member containing CNF, a sheet-like member which is advantageous in a drying process at the time of manufacturing is generally used.

On the other hand, conventionally, tubular bodies and plate-shaped bodies made of paper and the like (hereinafter, may be collectively referred to as "tubular bodies and the like") are widely used for various purposes. For example, Patent Document 3 discloses a core paper tube that can be used as a core for various sheets. Such a paper tube is advantageous in that it is economical and easy to process as compared with a tubular body made of another material, and recycled paper can also be used.

For tubular bodies and the like, both low weight and high strength are often required. For example, a tubular body for a winding core is desired to be lightweight from the viewpoint of ease of handling, but it is also required to have a certain strength or more so that it can withstand the process of winding a film or a sheet. Also, when used as a component of a car body or building material, it is important to achieve both low weight and high strength in order to reduce the weight and improve the strength of the finished product.

Japanese Patent Application Laid-Open No. 2015-044892 Japanese Unexamined Patent Publication No. 2015-040358 Japanese Unexamined Patent Publication No. 2011-241064

If a tubular body having high strength can be obtained by utilizing the characteristics of CNF, it is expected that both low weight and high strength can be achieved at a high level. However, the sheet-like member itself containing CNF is formed very thin in consideration of the ease of performing the above-mentioned drying step and the like. Therefore, even if an attempt is made to use the sheet-shaped member for the purpose of obtaining a tubular body or the like having high strength, it is difficult to obtain the desired strength by simply attaching the sheet-shaped member to the tubular body or the like, for example.

In view of the above-mentioned problems, the present invention relates to a CNF-containing body capable of obtaining a high-strength tubular body or the like by using a sheet-like member containing CNF, and a tubular body and a tubular body which is one form thereof. The purpose is to provide a manufacturing method.

The CNF-containing body according to the present invention has a structure in which at least a part thereof has a laminated structure in which sheet-like members containing CNF are laminated and integrated. According to this configuration, it is possible to obtain a highly strong tubular body or the like by using a sheet-like member containing CNF. It should be noted that the CNF-containing body here is not limited to a structure in which a laminated structure in which sheet-shaped members are laminated and integrated is provided in a part thereof, and is a concept including a structure in which the whole is the laminated structure.

Further, the tubular body according to the present invention is a tubular body formed in a tubular shape as a CNF-containing body having the above configuration, and the sheet-like member is wound and integrated so as to be laminated in the radial direction of the tubular body. It shall be configured. According to this configuration, it is possible to obtain a tubular body having high strength.

More specifically, as the above configuration, the sheet-shaped member is formed so that each of the contained CNFs is oriented in a predetermined direction, and the direction of the orientation substantially coincides with the axial direction of the tubular body. It may be a wound configuration. According to this configuration, the strength of the tubular body can be further increased, and the occurrence of wrinkles in the axial direction in the tubular body can be suppressed as much as possible. Here, "wound so that the direction of the orientation substantially coincides with the axial direction of the tubular" means that the entire sheet-shaped member is wound so as to substantially coincide with the axial direction. Not limited to this, when only a part of the sheet-like member is wound so as to substantially coincide with the axial direction, or when a plurality of sheet-like members are sequentially wound, only a part of the sheet-like member is wound. It is a concept that includes a form that is wound so as to substantially coincide with the axial direction.

Further, more specifically, the configuration may be such that the sheet-shaped member is wound around the outer peripheral surface of the tubular member so as to be laminated and reinforced. According to this configuration, it is possible to obtain an effective reinforcing effect on the tubular member.

More specifically, the tubular member, the sheet-shaped member, and adjacent layers of the sheet-shaped member may be fixed to each other by an adhesive. Further, more specifically, the tubular member may be a paper tube and may be used as a winding core for winding the wound object.

The first manufacturing method according to the present invention is a method for manufacturing a tubular body having the above configuration, which includes a step of stretching the sheet-shaped member, a step of applying an adhesive to the sheet-shaped member, and the tubular member. The method includes a step of winding a sheet-like member to which the adhesive has been applied around the outer peripheral surface of the above. According to this method, it is possible to stretch the sheet-shaped member so that the adhesive can be easily applied.

The second manufacturing method according to the present invention is the method for manufacturing a tubular body having the above configuration, and is a winding step of sequentially winding a plurality of the sheet-shaped members to which an adhesive has been applied on the outer peripheral surface of the tubular member. And a drying step of drying the adhesive, from after winding one sheet-like member around the tubular member to before winding all the sheet-like members around the tubular member. The method is such that the drying step is performed at least once. According to this method, the adhesive can be dried more reliably and easily, as compared with the case where the adhesive is dried after, for example, all the sheet-shaped members are wound around the tubular member.

According to the CNF-containing body according to the present invention, it is possible to obtain a highly strong tubular body or the like by using a sheet-like member containing CNF.

It is an external view near the end portion of the tubular body for a winding core which concerns on this embodiment. It is a schematic block diagram of the end portion of the tubular body for a winding core which concerns on this embodiment. It is a conceptual diagram of the manufacturing apparatus of the tubular body for a winding core which concerns on this embodiment. It is a flowchart of the manufacturing method using the manufacturing apparatus.

Embodiments of the present invention will be described below with reference to the drawings. However, the content of the present invention is not limited to the embodiment.

1. 1. Configuration of the Winding Core Tubular Body FIG. 1 is an external view of the vicinity of the end portion of the winding core tubular body 1 according to the present embodiment. Further, FIG. 2 is a schematic configuration diagram of an end portion (a portion indicated by α in FIG. 1) of the winding core tubular body 1. The tubular body 1 for a winding core (one form of the CNF-containing body according to the present invention) is reinforced by winding the sheet-like member 12 on the outer peripheral surface of the tubular member 11 so as to be laminated in several tens of layers or more. There is.

The tubular member 11, the sheet-shaped member 12, and the adjacent layers of the sheet-shaped member 12 are firmly fixed to each other by an adhesive. The multi-layered sheet-like member 12 forms a reinforcing portion 1a integrated by such adhesive fixing, and it is possible to effectively reinforce the tubular member 11 by utilizing the characteristics of the CNF.

The tubular member 11 is a conventional general paper tube or a similar one, and is used as a core around which the sheet-shaped member 12 is wound. The tubular member 11 may be a conventional cored paper tube. A tubular member made of a material other than paper may be applied as the tubular member 11, but if a paper tube is applied, it is easy to bond and fix the tubular member 12 to the sheet-shaped member 12 using an adhesive. It is also advantageous in terms of economy and workability. Further, although the tubular member in the present embodiment is cylindrical, a tubular member other than the cylindrical member may be adopted as long as it is possible to wind the sheet-shaped member.

The sheet-like member 12 is a thin sheet-like member containing a large amount of CNF. Since the sheet-shaped member 12 contains CNF, it is light and has high strength, is not easily thermally expanded, and has excellent gas barrier properties. As the sheet-shaped member 12, condenser paper or the like containing CNF may be adopted.

Further, the sheet-shaped member 12 is formed so that each of the contained CNFs is oriented in a predetermined direction. Since the method itself for forming the sheet-shaped member in which the CNF is oriented in this way is known, detailed description thereof will be omitted here.

2. 2. Method for manufacturing a tubular body for a winding core Next, an example of a method for manufacturing a tubular body for a winding core 1 will be described with reference to FIGS. 3 and 4. FIG. 3 shows a schematic block diagram of a manufacturing apparatus for a tubular body 1 for a winding core. The front-back and left-right directions (directions orthogonal to each other) in the following description are as shown in FIG. FIG. 4 shows a flowchart (flow of each process) of a manufacturing method using the apparatus shown in FIG.

Although not shown in FIG. 3, the manufacturing apparatus includes a mechanism for automatically performing a part or all of each process (for example, a mechanism for automatically transporting a sheet-shaped member 12, a mechanism for moving a tubular member 11, and the like. ) May be provided. In addition, a part or all of each process may be performed manually.

The winding core tubular body 1 manufacturing apparatus shown in FIG. 3 includes a roll stand 21, a cutting device 22, a stretching device 23, an adhesive coating device 24, a winding device 25, and a drying device 26. The roll-shaped original fabric, which is the source of the sheet-shaped member 12, is rotatably supported on the roll stand 21, and the tubular member 11 is set at a position to the left of the winding device 25.

The orientation direction of the CNF contained in the sheet raw fabric coincides with the direction in which the sheet original fabric is wound in a roll shape (that is, the circumferential direction of the roll shape). The roll-shaped central axis extends in the left-right direction, and the sheet material can be pulled out forward in order from the end.

The original sheet material supported by the roll stand 21 is pulled forward by an amount corresponding to the axial length of the tubular member 11, and is conveyed toward the stretching device 23. Further, the sheet material pulled out in this way is cut by the cutting device 22 arranged in front of the roll stand 21 (see S1 in FIG. 4). As a result, one sheet-shaped member 12 can be obtained.

The stretching device 23 is formed so that the sheet-shaped member 12 thus obtained can be pulled in a direction of spreading with an appropriate force. The stretching device 23 thus pulls and stretches the sheet-shaped member 12 (see S2 in FIG. 4) to bring the sheet-shaped member 12 into a more appropriate state. The stretching device 23 is not limited to the device for pulling and stretching the sheet-shaped member 12, and may be a device for stretching the sheet-shaped member 12 by another method. Further, the stretching device 23 may be a device that promotes stretching of the sheet-shaped member 12. The "step of stretching the sheet-shaped member" in the present invention is a concept including a step of actively stretching the sheet-shaped member and a step of promoting the stretching of the sheet-shaped member.

The sheet-shaped member 12 stretched as described above is conveyed to the adhesive coating device 24 further forward. The adhesive application device 24 applies the adhesive to the entire surface of the sheet-like member 12 received from the stretching device 23. Since the sheet-shaped member 12 is appropriately stretched by the stretching device 23, it is easy to appropriately apply the adhesive.

The adhesive coating device 24 includes, for example, a pair of upper and lower rollers (roller pairs) that rotate so as to sandwich the sheet-shaped member 12 from both sides and send it forward, and when the roller pair sandwiches and sends out the sheet-shaped member 12. It is configured to apply an adhesive to the sheet-shaped member 12. However, as the configuration of the adhesive coating device 24, various configurations can be adopted as long as the adhesive can be appropriately applied to the sheet-shaped member 12.

Normally, the adhesive is applied only to one side of the sheet-shaped member 12 (the inner surface side when wound around the tubular member 11), but it may be applied to both sides as necessary. As an adhesive to be applied to the sheet-shaped member 12, an adhesive containing vinyl acetate resin as a main component can be used, but an adhesive containing CNF (for example, CNF manufactured by Daisel Finechem Co., Ltd. (registered trademark "Cerish") It is expected that the strength or heat resistance will be improved by using the adhesive) containing)).

The sheet-shaped member 12 sent out from the adhesive application device 24 is set in the winding device 25 in a flat state that spreads back and forth and left and right. On the other hand, the tubular member 11 set in the winding device 25 is arranged near the left edge of the flat sheet-like member 12. The orientation direction of the CNF contained in the sheet-shaped member 12 and the axial direction (extending direction) of the tubular member 11 coincide with each other in the front-rear direction.

The tubular member 11 set in this way is moved so as to roll to the right. At this time, the flat sheet-like member 12 is wound around the outer peripheral surface of the tubular member 11 in order from the left edge (see S4 in FIG. 4). That is, the tubular member 11 is used as a core, and the sheet-shaped member 12 is completely wound around the tubular member 11. The number of turns when one sheet-shaped member 12 is wound around the tubular member 11 is determined by the width (horizontal dimension) of the sheet-shaped member 12. This number of turns is not particularly limited, but it should be set to an appropriate number of turns (for example, about 1 to several turns) in consideration of the fact that if it is too small, the production efficiency deteriorates, and if it is too large, it becomes difficult for the adhesive to dry. Is preferable.

After winding the sheet-shaped member 12 for one sheet (winding the sheet-shaped member 12 for one time) in this way, the tubular member 11 is left for a predetermined time, and the adhesive applied to the sheet-shaped member 12 is adhered. The agent is dried (see S5 in FIG. 4). At this time, the tubular member 11 may be transferred to the drying device 26. The drying device 26 is installed adjacent to the right side of the winding device 25, and can smoothly guide the tubular member 11 that has moved to the right in the winding device 25 into the drying device 26. A heater is arranged in the drying device 26, and it is possible to efficiently dry the adhesive applied to the sheet-shaped member 12.

After the drying, the tubular member 11 is set again in the left-side position of the winding device 25 (see S6 in FIG. 4). On the other hand, a new sheet-shaped member 12 is supplied to the winding device 25 from the original sheet sheet set on the roll stand 21. The sheet-shaped member 12 is also coated with an adhesive by going through the above-mentioned steps (S1 to S3 in FIG. 4), and is set in the winding device 25 in a flat state. In this state, the tubular member 11 is moved so as to roll to the right again, and as a result, the sheet-like member 12 is further wound around the tubular member 11 (see S4 in FIG. 4). After that, the above-mentioned drying step is performed again so as to dry the adhesive applied to the sheet-shaped member 12 wound this time (see S5 in FIG. 4).

The series of steps described above (S1 to S6 in FIG. 4) is repeated until the number of times the sheet-like member 12 is wound around the tubular member 11 reaches a specified number of times (see S7 in FIG. 4). This specified number of times is set to an appropriate number of times in advance so that the necessary reinforcing effect for the tubular member 11 can be obtained. After the drying step (see S5 in FIG. 4) is completed, if the number of times the sheet-shaped member 12 is wound reaches the specified number of times (when “YES” in S7 in FIG. 4), the core tubular body 1 is used. Production is complete.

By the manufacturing process described above, the tubular body 1 for a winding core is obtained, in which the sheet-shaped member 12 is wound around the outer peripheral surface of the tubular member 11 so as to be laminated and reinforced. Further, although it is difficult to obtain the reinforcing effect if the sheet-shaped member 12 is not sufficiently dried, in the present embodiment, consideration is given so that the sheet-shaped member 12 is sufficiently dried to obtain the desired reinforcing effect.

In the present embodiment, since the drying step is performed every time one sheet-shaped member 12 is wound, the sheet-shaped member 12 can be dried as reliably and easily as possible. Instead of performing the drying step every time one sheet-shaped member 12 is wound, the drying step may be performed every time a plurality of sheet-shaped members 12 are wound, for example, within a range that does not hinder sufficient drying. good. If at least one drying step is performed between the time when one sheet-shaped member 12 is wound around the tubular member 11 and the time before all the sheet-shaped members 12 are wound around the tubular member 11, the sheet is formed. It is possible to dry the sheet-shaped member 12 more reliably and easily as compared with the case where the drying step is performed after all the winding of the shaped member 12 is performed.

Further, the sheet-shaped member 12 is wound around the tubular member 11 so that the orientation direction of the CNF coincides with the axial direction of the tubular member 11. The sheet-shaped member 12 containing CNF has a high tensile elastic modulus and tensile strength in the orientation direction of CNF (see Table 1 and its description below), and by winding the sheet-shaped member 12 in this way, an efficient reinforcing effect is achieved. It is possible to obtain a tubular body 1 for a winding core having a higher flexural modulus and bending strength. From the viewpoint of the reinforcing effect, it is preferable to wind all the sheet-shaped members 12 in this way as in the present embodiment, but it is also possible to wind only a part of the sheet-shaped members 12 in this way.

Further, in the sheet-shaped member 12, for example, when the applied adhesive is dried, wrinkles are most unlikely to occur in the direction in which the CNF contained is extended, that is, in the orientation direction of the CNF. In the present embodiment, since the orientation direction of the CNF coincides with the axial direction of the tubular member 11, it is possible to suppress wrinkles in the axial direction, which have a relatively large effect on the quality of the winding core tubular body 1, as much as possible. However, the present invention is not limited to this embodiment, and the sheet-shaped member 12 may be wound so that the orientation direction of the CNF is different from the axial direction of the tubular member 11.

3. 3. Evaluation test by each example (1) Evaluation of sheet-shaped member Three types of CNF-containing papers A to C are given as specific examples of the sheet-shaped member 12 containing CNF, and the results of comparing the characteristics of each with high-quality paper are shown. It is shown in Table 1. The MD direction in Table 1 is the direction in which the sheet is rolled into a roll (the orientation direction of the CNF in the case of CNF-containing paper), and the CD direction is a direction orthogonal to the MD direction. The strength ratio indicates the ratio of the tensile elastic modulus or the tensile strength to the value of the woodfree paper.

From the viewpoint of preventing deformation due to the reinforcing effect and improving the strength, it is preferable that the sheet-like member has a high tensile elastic modulus and tensile strength. As shown in Table 1, all CNF-containing papers have generally better characteristics than high-quality papers. In particular, the CNF-containing paper A, which has a higher density than the others, has very excellent properties.

(2) Evaluation of a tubular body for a core The tubular body 1 for a core (standard inner diameter 12 mm, standard outer diameter 14.6 mm) using the above-mentioned CNF-containing papers A to C as a sheet-like member 21 is designated as Examples 1 to 3, respectively. Table 2 shows the results of bending tests for each example. A tubular body for a core to which high-quality paper is applied instead of the sheet-shaped member 21 is used as a comparative example, and the results of the comparative example are also shown in the same manner. The strength ratio indicates the ratio to the value of the comparative example regarding the flexural modulus or the bending strength. Further, in each example, the tubular member 11 (core material) around which the sheet-shaped member is wound has a cylindrical shape having an inner diameter of about 12 mm and a thickness of about 0.5 mm. The conditions for the bending test were to set the span length to 80 mm and press the center of the sample with a bending wedge jig at a speed of 5 mm / min.

As shown in Table 2, better results were obtained in all the examples than in the comparative examples in terms of both the flexural modulus and the bending strength. In particular, in Example 1 in which the CNF-containing paper A was used as the sheet-shaped member 12, the flexural modulus was 6.6 times and the bending strength was 2.4 times that of the comparative example, and very excellent results could be obtained. ..

Further, the tubular body 1 for a core (standard inner diameter 6 mm, standard outer diameter 8.6 mm) having a relatively small diameter dimension in which the CNF-containing papers A and B are used as the sheet-shaped member 12 is referred to as Examples 4 and 5, respectively, and these are carried out. Table 3 shows the results of the same bending test for the example. The thickness of the tubular member 11 (standard thickness 0.5 mm) and the thickness of the reinforcing portion X (laminated portion of the sheet-shaped member 12) (standard thickness 0.85 mm) are common to all the embodiments. As shown in Table 3, if the diameter dimension of the winding core tubular body 1 is reduced without changing the thickness, the flexural modulus and the bending strength are significantly improved.

In addition to the above-mentioned evaluation test results, when the adhesion between the layers of the sheet-like member is not sufficient (when an adhesive which is difficult to obtain a good adhesive state is used), the adhesion is sufficient as compared with the case where the adhesion is sufficient. The test result that the bending strength is inferior was obtained. From this result, it can be said that it is desirable to use an adhesive that can satisfactorily bond the sheet-like members to each other (for example, a vinyl acetate-based adhesive) as the adhesive used for bonding between the layers.

4. Summary As described above, the winding core tubular body 1 according to the present embodiment is reinforced by winding a sheet-shaped member 12 containing CNF around the outer peripheral surface of the tubular member 11 so as to be laminated. Therefore, according to the winding core tubular body 1, the reinforcing effect is effectively obtained by using the sheet-shaped member 12.

The core tubular body 1 formed of the paper tubular member 11 (core material) and the sheet-like member 12 is formed into a core component (FRP core) formed of FRP (Fiber Reinforced Plastics). In comparison, it is environmentally friendly, has excellent recyclability, and has excellent surface smoothness because glass fibers and the like are not exposed. Further, the winding core tubular body 1 according to the present embodiment has a strength equal to or higher than that of the FRP core due to the reinforcing effect of using the sheet-shaped member 12.

The tubular body according to the present invention is not limited to the winding core as in the present embodiment, and can be used for various purposes. In particular, the tubular body is suitable for applications that take advantage of the characteristics of CNF (because it is derived from plant fiber, it has a small environmental load associated with production and disposal, is light and strong, does not easily expand thermally, and has excellent gas barrier properties). be. Further, there is room for application of the tubular body according to the present invention to applications that are difficult to apply with a tubular body containing glass fiber or the like.

For example, the tubular body according to the present invention is expected to be applied to (A) automobiles and bicycles, (B) home appliances and furniture, (C) building materials, and (D) sports equipment. With respect to the above (A), if the tubular body according to the present invention is used for a frame or a rim, the weight can be reduced as compared with a metal material such as aluminum or titanium, and fuel efficiency and running performance are expected to be improved. Regarding (B) above, the tubular body according to the present invention is a housing for acoustic home appliances using the acoustic characteristics of a cellulose material, a cushioning material for large household appliances such as an air conditioner using the cushioning characteristics, or a natural material using the material as it is. It can be expected to be applied to oriented furniture parts and columns. With respect to the above (C), the tubular body according to the present invention can be expected to be applied to a handrail that makes use of the feel of paper that is not cold to the touch and a core material that utilizes moisture absorption / desorption. Regarding (D) above, the tubular body according to the present invention is designed so that characteristics such as high strength, weight reduction, cushioning property, or toughness are suitable for the content of the competition, and metal or carbon such as a golf club, a baseball bat, or a fishing rod. It can be applied as an alternative member to a fiber member.

Regarding the winding method of the sheet-shaped member containing CNF, in the above-described embodiment, a method (flat winding) in which the winding position does not change in the axial direction is adopted, but the winding position is shifted in the axial direction while winding. A method (that is, spiral winding) may be adopted.

Further, as the form of the tubular body according to the embodiment of the present invention, in addition to the form in which the tubular member is reinforced by winding the sheet-like member containing CNF so as to be laminated, the sheet-like member without the tubular member is provided. There is also a form composed only of. The tubular body of this form is, for example, a sheet-like member in which a sheet-like member coated with an adhesive is wound around a cylindrical or columnar core so as to be laminated in the radial direction and integrated into a cylindrical shape. It is obtained by extracting the core from the laminated body. Also in this form, either the flat winding or the spiral winding described above may be adopted as the winding method of the sheet-shaped member.

The CNF-containing body according to the present invention may be provided with a laminated structure in which sheet-shaped members containing CNF are laminated and integrated at least in a part thereof, and the sheet-shaped member containing CNF may be provided by this configuration. It is possible to obtain a highly strong tubular body or the like by using it. Therefore, as the embodiment of the present invention, in addition to the above-mentioned tubular body form, a plate-like body form and the like can also be mentioned. In order to obtain a CNF-containing body which is a plate-shaped body, the sheet-shaped members may be laminated and integrated so as to be sequentially stacked. The CNF-containing material according to the present invention can have various shapes by changing the laminated form of the sheet-shaped members and the like.

Although the embodiments of the present invention have been described above, the configuration of the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the invention. That is, the above embodiment should be considered to be exemplary in all respects and not restrictive. It is understood that the technical scope of the present invention is shown by the scope of claims, not the description of the above embodiment, and includes all modifications belonging to the meaning and scope equivalent to the scope of claims. Should be.

The present invention can be used as an example for a winding core for winding a wound object.

1 Tubular body for winding core 1a Reinforcing part 11 Tubular member 12 Sheet-like member 12a Sheet original fabric 21 Roll stand 22 Cutting device 23 Stretching device 24 Adhesive application device 24a Upstream roller vs. 24b Downstream roller vs. 25 Winding device 26 Drying device 26a heater

Claims (1)

A CNF-containing body characterized in that at least a part thereof is provided with a laminated structure in which sheet-like members containing CNF are laminated and integrated.

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