JP7328496B2 - Structure and method for manufacturing structure - Google Patents

Description

The present invention relates to a structure and a method of manufacturing the structure.

Medical fixtures such as plaster casts, braces, and supporters are required to fit the affected area, which has a different shape for each patient, with high adhesion and to maintain sufficient strength to protect the affected area during use. Conventionally, a cast bandage made of gypsum powder and cotton cloth has been used, but it has been difficult to ensure high adhesion to the affected area, which has a complicated three-dimensional shape.

Under such circumstances, Patent Literature 1 proposes a medical fixing material and a medical fixing tool using a thermoplastic resin. In Patent Document 1, the thermoplastic resin is deformed along the affected part of the human body at a temperature at which it becomes soft.

JP 2017-55884 A

However, since the medical fixture described in Patent Document 1 uses a thermoplastic resin as a main structural body, the following problems occur. Since the thermoplastic resin is deformed along the affected part of the human body, the melting point (melting temperature range) of the thermoplastic resin cannot be extremely higher than the human body temperature in order to avoid burns to the patient. is limited. Therefore, sufficient strength for the purpose cannot always be obtained. In addition, medical fixtures with a melting point close to body temperature soften and deform even with a slight increase in temperature.

The present invention has been made in view of such circumstances, and provides a structure and a method for manufacturing the structure that can maintain high strength even at high temperatures in a structure that has a high degree of freedom in shape during molding. intended to

According to the invention, a structure comprises a substrate layer and a covering layer, said substrate layer being formed from a thermoplastic material having thermoplasticity, wherein said thermoplastic material exerts an external force. The coating layer is formed of a non-thermoplastic material that does not have thermoplasticity, and covers at least a part of the base layer to change the shape of the structure. A structure is provided that is configured to be maintainable.

The structure according to the present invention can be shaped and shaped with a high degree of freedom by utilizing the properties of the thermoplastic resin used for the base material layer, and after the shape of the base material layer is determined, the non-thermoplastic material By forming the coating layer, there is an advantageous effect that high strength can be maintained even at high temperatures.

1 is a perspective view schematically showing a structure according to a first embodiment; FIG. [FIG. 2A] A partially enlarged front view of the structure of FIG. [FIG. 2B] A cross-sectional view cut along the AA cross section in FIG. 2A. [Fig. 3A] [Fig. 3B] Diagrams showing a method for manufacturing the base material layer 2 of the structure according to the first embodiment. [Fig. 4A] [Fig. 4B] Diagrams showing a method of manufacturing the covering layer 3 of the structure according to the first embodiment. FIG. 2 is a schematic diagram of applying the structure according to the first embodiment to a detachable ankle cast. [FIG. 6A] A partially enlarged surface view of the structure according to the second embodiment. [FIG. 6B] A cross-sectional view cut along the BB cross section in FIG. 6A.

Embodiments of the present invention will be described below with reference to the drawings. Various features shown in the embodiments shown below can be combined with each other.
1. First Embodiment: Configuration of Structure 1

Section 1 describes the configuration of the structure 1 according to the embodiment (first embodiment) of the present invention. 1 is an overall view of the structure 1, FIG. 2A is a partially enlarged front view of the structure of FIG. 1, and FIG. 2B is a cross-sectional view taken along the line AA in FIG. 2A.

<Base material layer 2>
In FIG. 2A, the substrate layer 2 is a laminated structure in which horizontal substrate layers 2a and vertical substrate layers 2b are alternately laminated. It is configured. Note that the base material layer 2b in the vertical direction exists in the back layer in FIG. 2A and does not appear on the surface. In FIGS. 2A and 2B, the base layer 2 (2a, 2b) is made of a thermoplastic material (an example of a "linear resin" in the claims) having orthogonal straight lines. Voids 21 are provided between a plurality of straight thermoplastic material present in the same layer. That is, it has a lattice shape as a whole.

In other words, the substrate layer 2 is a laminated structure in which a plurality of layers are laminated, and each layer is made of a plurality of linear resins arranged in parallel. Although a linear configuration is shown, it is not intended to be a limiting shape. In the case of straight lines, they may intersect at an arbitrary angle, and a curved aggregate may be used.

The cross-sectional view shown in FIG. 2B shows a concave shape from top to bottom. The mode of shape change is not limited, and the shape can be fixed by lowering the temperature after deforming within the thermoplastic temperature range in which the thermoplastic material can be deformed.

A shape memory material such as a shape memory polymer (SMP) can be used for the base material layer 2 . A shape memory polymer is a material having a shape memory property, and has a property of elastically returning to its original shape when heated to a predetermined recovery temperature (glass transition temperature: Tg) or higher. The glass transition temperature Tg is, for example, 30 to 100° C. Specifically, for example, , 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100 ° C. It may be in the range between any two.

When a shape memory polymer is used for the substrate layer 2, the secondary shape is fixed by applying an external force at a temperature exceeding Tg to shape it into a secondary shape, and cooling to a temperature below Tg while maintaining the external force. At temperatures below Tg, it does not return to its original shape even when the external force is removed. On the other hand, when it is heated to a temperature exceeding Tg and no external force is applied, it returns to its original shape due to its elasticity. The original shape can be molded into a desired shape using a 3D printer that molds a shape memory polymer in a melted state, for example. Shape memory polymers include polymers having rubber elasticity, such as polynorbornene, transpolyisoprene, styrene-butadiene copolymer, and polyurethane.

A base material layer 2 using a shape memory polymer can be used, for example, in medical fixtures. By using an average shape corresponding to each part of the human body as the original shape, it is possible to repeatedly perform fine adjustments corresponding to individual patients.

The shape memory polymer can be used alone, but may contain other components as long as the shape memory properties are not impaired. Components other than the shape memory polymer include resins such as polyolefins such as polyethylene and polypropylene, fillers, and the like. When the shape memory property is actively utilized, the proportion of the shape memory polymer in the substrate layer 2 is preferably, for example, 50 to 100% by mass, specifically, for example, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100% by mass, and the numerical values illustrated here It may be in the range between any two. At this time, the recovery temperature of the base material layer 2 as a whole usually coincides with the glass transition temperature of the shape memory polymer.

<Coating layer 3>
The covering layer 3 is arranged to cover at least a portion of the base material layer 2 . 2A and 2B, the entire space between the base material layers 2 (2a, 2b) is filled with the coating layer 3, but it is not necessary to fill the entire region of the structure 1 with the coating layer 3. It is also possible to cover only a partial area.

A non-thermoplastic material having no thermoplasticity is used for the coating layer 3 . It is important that the coating layer 3 maintains a high modulus of elasticity even at high temperatures at which the base material layer 2 having thermoplasticity becomes soft.

Inorganic materials such as cement and gypsum can also be used for the coating layer 3, but resins having moderate flexibility and low brittleness are preferable for medical fixtures and the like. Although the manufacturing method will be described later, after forming the substrate layer 2 first, a method of filling the space of the substrate layer 2 with the coating layer 3 can be adopted. can be used. Specific examples of UV resins include acrylate-based monomers and oligomers as radical curing types, alicyclic epoxies, glycidyl-type epoxies, oxetane compounds, vinyl ether monomers as cation-curing types, and two-liquid mixtures as room temperature curing resins. A type epoxy resin or the like can be used, but is not limited to these materials.

In other words, the base material layer 2 has a plurality of holes, and the covering layer 3 is configured to be able to maintain the shape of the structure 1 by covering at least a portion of the plurality of holes.

2. Method for Manufacturing Structure 1 A method for manufacturing the structure 1 is shown in order of steps in FIGS. 3A, 3B, 4A, and 4B. 3A and 3B show the manufacturing process of the base material layer 2, and FIGS. 4A and 4B show the manufacturing process of the coating layer 3. As shown in FIG. Description will be made below with reference to the drawings.

<Base material layer forming step>
In FIG. 3A, the base material layer 2 is formed by a 3D printer. Here, as an example, the nozzle NZ is horizontally scanned, and the raw material of the base material layer 2, which is a thermoplastic material, is linearly discharged from the nozzle NZ in a heated state to form a linear resin. In the layers forming the same horizontal plane, the linear resins having thermoplasticity are positioned in parallel with the stretching direction being the same. The base material layer is formed into a shape, and the base material layer is formed into a primary shape forming step. Here, the primary shape is a shape in which linear resins are laminated in a grid pattern, but the shape is not limited to this.

Subsequently, as shown in FIG. 3B, an external force is applied to the base material layer 2 so as to form a desired outer shape. In FIG. 3B, an external force is applied so as to dent the base material layer from above, which is the step of forming the secondary shape of the base material layer. When the base material layer 2 is a general thermoplastic material, keep applying an external force in the vicinity of the flexible melting point, and when using a shape memory polymer for the base material layer 2, across the glass transition temperature Tg. to form a secondary shape. As described in Section 1, the secondary shape, which is the final shape of the base material layer 2, is not limited and can be any shape.

FIG. 3A and FIG. 3B explained the case where the base material layer primary shape forming process and the base material layer secondary shape forming process are separated. By simultaneously performing vertical scanning with another nozzle NZ, it is also possible to combine the steps of forming the base material layer 2 into one step.

<Coating layer forming step>
After the step of forming the base material layer 2 is completed, the coating layer 3 is formed. Here, UV resin is used as the material of the coating layer 3 as an example. FIG. 4A shows a state in which the base layer 2 is impregnated with the liquid resin 31 that is the raw material of the coating layer 3 before curing. By adjusting the size of the voids in the base material layer 2 and the viscosity of the liquid resin 31 , it is possible to spread the liquid resin 31 in the voids 21 of the base material layer 2 . FIG. 4A shows the case where the substrate layer 2 is impregnated with the liquid resin 31. However, when the substrate layer 2 is thin or when it is desired to form the coating layer 3 only on the surface of the structure 1, the liquid resin It is also possible to apply 31.

FIG. 4B shows a structure in which the base material layer 2 is impregnated with the liquid resin 31 and is cured by irradiating with ultraviolet rays. Since UV resin is used here as an example of the material of the coating layer 3, ultraviolet irradiation is used. In the case of a photocurable resin, the coating layer can be formed by irradiating light with a wavelength suitable for curing, and in the case of a room temperature curable resin, the resin can be left at room temperature until curing progresses, thereby completing the structure 1 .

3. Application of Structure 1 to Medical Fixture Fig. 5 shows an example in which the structure 1 is applied as a medical fixation tool to a removable cast (sine) for an ankle FT. Here, a shape memory polymer is used for the base material layer 2 (not shown), and a UV resin is used for the coating layer 3 (not shown). A cast with high adhesion to the affected part of the ankle FT, which has a complicated shape including the heel, was created.

4. Second Embodiment Section 4 describes a structure 1 according to a second embodiment. That is, the structure 1 according to the present embodiment may be further ingenuity in the following aspects.

In the explanation up to the previous section, all the voids after the formation of the base material layer 2 were filled with the coating layer. Therefore, it is possible to have porosity as the structure 1 after completion. In other words, the coating layer 3 has a plurality of pores 4 and is configured such that the structure 1 is porous.

FIG. 6A shows a partially enlarged surface view of a structure 1 according to a second embodiment having a plurality of pores 4 and having overall porosity. FIG. 6B shows a cross-sectional view cut along BB in FIG. 6A. Here, the pores communicate with the outside both in the horizontal direction and the vertical direction, but it is also possible to limit the directionality of the pores by adjusting the density of the substrate layer 2 layer by layer. Can be anisotropic.

Furthermore, it is possible to prepare a closed space (not shown) in advance when forming the base material layer 2 so that the coating layer 3 does not enter. The elastic modulus of the structure 1 as a whole can be adjusted by changing the deposition ratio of the base material layer 2, the coating layer 3, and the voids.

5. Conclusion As described above, according to the present embodiment, it is possible to implement the structure 1 that can maintain high strength even at high temperatures in a structure that has a high degree of freedom in shape during molding.

Such a structure 1 comprises a substrate layer 2 and a coating layer 3, said substrate layer 2 being formed from a thermoplastic material having thermoplasticity, wherein said thermoplastic material is deformed by applying an external force. The covering layer 3 is formed of a non-thermoplastic material that does not have thermoplasticity, and covers at least a part of the base layer 2 to maintain the shape of the structure. configured as possible.

Moreover, in the structure, the manufacturing method of the structure 1 can be carried out, which has a high degree of freedom in shape during molding and can maintain high strength even at high temperatures.

This manufacturing method is a manufacturing method of the structure 1, and includes a substrate layer 2 forming step and a coating layer 3 forming step. The substrate layer 2 in the structure is formed by stacking with a printer, and in the coating layer 3 forming step, at least a part of the substrate layer 2 is impregnated or coated with a non-thermoplastic material that does not have thermoplasticity. and subsequently curing the non-thermoplastic material to form the coating layer 3 on the structure 1 .

Finally, while various embodiments of the invention have been described, these have been presented by way of example and are not intended to limit the scope of the invention. The novel embodiment can be embodied in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. The embodiment and its modifications are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

Reference Signs List 1: structure 2: base material layer 2a: base material layer 2b: base material layer 21: void 3: coating layer 31: liquid resin 4: void NZ: nozzle FT: ankle

Claims (2)

A method for manufacturing a structure,
A base material layer forming step and a coating layer forming step,
In the base layer forming step, a thermoplastic material having thermoplasticity is laminated by a 3D printer to form a base layer in the structure,
The base layer forming step includes a base layer primary shape forming step and a base layer secondary shape forming step,
In the base material layer primary shape forming step, the base material layer in the structure is formed by stacking with the 3D printer,
In the base layer secondary shape shaping step, the base layer after the base layer primary shape shaping step is shaped into a final shape by applying an external force to the base layer,
In the coating layer forming step,
impregnating or applying a non-thermoplastic material having no thermoplasticity to at least a portion of the base layer after the base layer secondary shape forming step;
subsequently curing the non-thermoplastic material to form a coating layer on the structure;
Production method. In the manufacturing method according to claim 1 ,
said thermoplastic material is a shape memory material comprising a shape memory polymer;
Production method.