JP2017094574A - Method for producing heat insulation material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a heat insulation material high in heat insulation properties and dimensional stability and further excellent in strength.SOLUTION: Provided is a method for producing a heat insulation material 1 comprising: a step where the inside of a frame member having a bottom face part and side face parts is filled with isocyanato and polyol; and a step where the inside of the frame member is disposed with plant pieces 3. Also, the production method step where isocyanato and polyol are reacted under ordinary pressure or under reduced pressure to produce polyurethane. Then, by the reaction between the isocyanato and polyol, the foamed polyurethane 2 is produced at the inside of the frame member, and, by the polyurethane 2, the plant pieces 3 are adhered each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a heat insulating material. More specifically, the present invention relates to a method for producing a heat insulating material in which a foam produced by a reaction between an isocyanate and a polyol is combined with a light and porous herbaceous plant.

  Insulating materials can be broadly divided into two types: foam and fiber. Examples of the fiber heat insulating material include glass wool and rock wool, and examples of the foam heat insulating material include resin foams such as urethane foam, phenol foam, and polystyrene foam. Since these heat insulating materials have a low density and do not have sufficient strength even if they are plate-shaped, a resin plate or the like is often bonded to the surface of the heat insulating material. However, when the resin plates are bonded together, the heat insulation performance may deteriorate. Furthermore, since it is difficult to improve the adhesiveness between the resin plate and the heat insulating material, there are problems such as insufficient strength improvement.

  On the other hand, as materials having relatively low thermal conductivity, there are particle boards made of particles, chips or fibrous plant pieces and an adhesive, and plant boards such as fiber boards. In general, a particle board or a plant board is obtained by mixing an adhesive with a plant piece obtained by pulverizing a woody material of a conifer or a broad-leaved tree, and then hot pressing the mixture.

  As such a particle board, what is manufactured by adhere | attaching a wood chip with a foaming resin adhesive conventionally is disclosed (for example, refer patent document 1). A step of applying an adhesive to a wood chip, a step of forming the forming mat by accumulating the wood pieces to which the adhesive has been applied, and a step of hot pressing the forming mat into a plate shape Also disclosed is a method of manufacturing a wood board provided with (see, for example, Patent Document 2). In Patent Document 2, it is also disclosed to use a two-component adhesive composed of a polyisocyanate compound and a polyol compound as the adhesive.

Japanese Patent Laid-Open No. 57-182420 JP 2012-67242 A

  However, in Patent Documents 1 and 2, a mixture of plant pieces and an adhesive is deformed by compression and the plant pieces are brought into contact with each other so that the plant pieces are bonded and formed into a plate shape. For this reason, the density of the plant pieces increases due to the compression step, and the density of the resulting board also increases, so that the thermal conductivity may increase and the thermal insulation may become insufficient. In addition, since the plant pieces are compressed and deformed and fixed by this compression process, there is a problem that the dimensional stability is lowered, for example, when the moisture enters the formed board, the plant pieces expand and the board expands. . Furthermore, since the rigid cell wall in the plant piece is broken and fixed by compression, there is a possibility that sufficient strength as a board cannot be obtained.

  The present invention has been made in view of such problems of the prior art. And the objective of this invention is providing the manufacturing method of the heat insulating material with high heat insulation and dimensional stability, and also excellent in intensity | strength.

  In order to solve the above problems, a method of manufacturing a heat insulating material according to an aspect of the present invention includes a step of filling an isocyanate and a polyol inside a frame member having a bottom surface portion and a side surface portion, and an interior of the frame member. And a step of disposing a plant piece. Further, the production method includes a step of producing a polyurethane by reacting an isocyanate with a polyol under normal pressure or reduced pressure. And the foamed polyurethane produces | generates inside a frame member by reaction of isocyanate and a polyol, and plant pieces are adhere | attached by the said polyurethane.

  According to the present invention, since the voids between the plant pieces are filled with the polyurethane foam, a compression step between the plant pieces and the adhesive becomes unnecessary. Therefore, the obtained heat insulating material has a low density, and high heat insulating properties can be obtained. In addition, since the plant pieces are compressed and deformed and are not fixed, expansion is suppressed even when moisture enters the heat insulating material. Furthermore, since the breakage of the cell wall is suppressed, sufficient strength as a heat insulating material can be obtained.

It is the schematic which shows the example of the heat insulating material which concerns on this embodiment. It is the schematic which shows the example of arrangement | positioning of the plant piece which concerns on this embodiment. It is the schematic which shows the example of the plant piece which concerns on this embodiment. It is the schematic which shows the other example of arrangement | positioning of the plant piece which concerns on this embodiment. It is the schematic which shows the other example of arrangement | positioning of the plant piece which concerns on this embodiment. It is the schematic which shows the example of a frame member.

  Hereinafter, the manufacturing method of the heat insulating material which concerns on this embodiment is demonstrated in detail. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.

  The heat insulating material according to the present embodiment includes a plurality of plant pieces, and further, voids existing between the plant pieces are filled with polyurethane foam. And as will be described later, in the method for manufacturing a heat insulating material according to the present embodiment, when filling between the plant pieces with polyurethane, the plant pieces and the polyurethane are not pressurized from the outside. Therefore, the compressive deformation of the plant pieces and polyurethane is suppressed, and the obtained heat insulating material has a low density and the thermal conductivity is lowered, so that the heat insulating property can be improved.

  Specifically, as shown in FIG. 1, the heat insulating material 1 according to this embodiment includes a foam 2 made of polyurethane and a plurality of plant pieces 3. The plant piece 3 has a long, substantially cylindrical shape, and is oriented in one direction inside the foam 2. The space between the plant pieces 3 is filled with the foam 2, and the periphery of the plant piece 3 is covered with the foam 2. With such a configuration, the plurality of plant pieces 3 are bonded by the foam 2 to form a plate-like heat insulating material 1.

  As the plant piece 3 that can be used in the heat insulating material 1, a plant piece obtained from the wood of a conifer or a broad-leaved tree can be used. That is, as the plant piece 3, a plant piece made of a hard portion inside the trunk of a conifer or a broad-leaved tree can be used.

  Moreover, the plant piece obtained from the stem core of a herbaceous plant can also be used as the plant piece 3, for example, it is preferable to use at least one stem core selected from the group consisting of jute, kenaf and bagasse, for example. The stem cores of herbaceous plants such as jute, kenaf and bagasse are lightweight, and the stem core structure is porous. Therefore, the density of the molded heat insulating material 1 can be reduced, and as a result, the obtained heat insulating material 1 can obtain high heat insulating properties. Furthermore, since the stem core of the herbaceous plant is long, a sufficiently long plant piece 3 can be easily obtained. Moreover, since the fiber of the stem core of a long herbaceous plant is held inside the heat insulating material 1, the strength in the direction along the fiber in the heat insulating material 1 can be increased.

  In the heat insulating material 1, the orientation of the plant pieces 3 in the polyurethane foam 2 is not particularly limited. The plant piece 3 may be oriented in one direction within the foam 2. That is, as shown in FIG. 1, in the foam 2, the elongate plant piece 3 may be arrange | positioned along the X-axis direction. Moreover, the plant piece 3 may be orthogonally oriented in the foam 2. That is, as shown in FIG. 2, in the foam 2, the plant piece 3 of the first stage 4 that is the uppermost stage is arranged along the X-axis direction, and the plant piece 3 of the second stage 5 that is the middle stage is You may arrange | position along the Y-axis direction orthogonal to a X-axis direction. In addition, the plant piece 3 of the 3rd step | stage 6 which is the lowest step is arrange | positioned along the X-axis direction. By setting it as such a structure, since the space | gap between the plant pieces 3 can be reduced more, it becomes possible to reduce content of a polyurethane. Furthermore, it is possible to easily obtain the heat insulating material 1 that is lighter in weight and more excellent in strength and dimensional stability by using the strength inherent to the plant piece 3 as it is. In order to reduce the in-plane strength anisotropy of the heat insulating material 1, it is preferable to orient the plurality of plant pieces 3 orthogonally as shown in FIG. Further, when it is desired to particularly increase the strength in one direction in the heat insulating material 1, it is preferable to orient the plurality of plant pieces 3 in one direction as shown in FIG.

  Although the length of the plant piece 3 is not specifically limited, It is preferable that it is 50 mm or more. Thereby, since it becomes easy to arrange the plant piece 3 in parallel from the edge part of the heat insulating material 1, and the space | gap between the plant pieces 3 can be reduced more, it is possible to improve the adhesiveness of plant pieces. Become. Further, it is possible to obtain a heat insulating material that is lightweight and further excellent in strength and dimensional stability by utilizing the strength inherent to the long plant piece 3.

  The specific gravity of the plant piece 3 is not particularly limited, but is preferably 0.2 or less. When the specific gravity of the plant piece 3 is such a value, since the plant piece 3 is porous, the density of the molded heat insulating material 1 can be reduced and the heat insulating property can be improved.

  The shape of the plant piece 3 and the aspect ratio of the plant piece ([length in the longitudinal direction of the plant piece] / [diameter of the cross section perpendicular to the longitudinal direction]) are not particularly limited. The plant piece 3 can have various shapes such as a powder shape, a fiber shape, a chip shape, a needle shape, and a rod shape, and can be appropriately selected according to desired heat insulation performance and strength.

  For example, as shown in FIG.1 and FIG.2, the shape of the plant piece 3 can be made into the elongate column shape. However, as described above, the shape of the plant piece is not limited to the columnar shape, and as shown in FIG. 3, the columnar plant piece is cut and a long plant piece 3A having a fan-shaped cross section is used. Is also preferable. By using such a fan-shaped plant piece 3A, the gap between the plant pieces 3A can be further reduced, so that the adhesiveness between the plant pieces 3A can be improved.

  FIG. 4 shows an arrangement example of the plant pieces 3A in the heat insulating material when the fan-shaped plant pieces 3A are used. As shown in FIG. 4, the plant pieces 3 </ b> A in the first stage 4 as the uppermost stage are arranged along the X-axis direction, and the plant pieces 3 </ b> A in the second stage 5 as the middle stage are perpendicular to the X-axis direction. Arranged along the direction. And the plant piece 3A of the 3rd step | paragraph 6 which is the lowest step is arrange | positioned along the X-axis direction.

  FIG. 5 shows an arrangement example of the plant pieces 3A in the heat insulating material when the plant pieces 3A having a short length are used. In the arrangement example in FIG. 5, the plant pieces 3 </ b> A in the first stage 4 are arranged along the X-axis direction, and the plant pieces 3 </ b> A in the second stage 5, which is the middle stage, are orthogonal to the X-axis direction. Arranged along the Y-axis direction. And the plant piece 3A of the 3rd step 6 is arrange | positioned along the X-axis direction. However, in FIG. 5, it arrange | positions so that the short plant piece 3A may be joined in a longitudinal direction. Even if it arrange | positions so that the short plant piece 3A may be succeeded in this way, the heat insulating material which has high heat insulation can be obtained.

  In the heat insulating material 1, the foam 2 is made of polyurethane. Polyurethane is excellent in foaming properties and has high adhesiveness to the plant pieces 3, so that it can be preferably used as the foam 2. That is, the isocyanate, which is a raw material of polyurethane, reacts with polyol, and also reacts with cellulose, hemicellulose, lignin, and the like, which are components in plant pieces, and moisture. Therefore, by reacting the isocyanate and the polyol in a state of being mixed with the plant pieces, foaming occurs and the plant pieces can be firmly bonded to each other with polyurethane.

In the heat insulating material 1, it is preferable that the density of the polyurethane which is the foam 2 is 0.1 g / cm ³ or less. When the density of the polyurethane is such a value, the heat insulating property of the foam 2 made of polyurethane is improved, so that the heat insulating property of the whole heat insulating material can be improved.

  The isocyanate that is a raw material of the polyurethane is not particularly limited. As the isocyanate, polyisocyanate which is a compound having two or more isocyanate groups (—NCO) in one molecule can be used. As the isocyanate, for example, at least one of diphenylmethane diisocyanate (MDI) and tolylene diisocyanate (TDI) can be used.

  The polyol which is a raw material of polyurethane is not particularly limited. Polyols are compounds having two or more hydroxyl groups (—OH) in one molecule, and can be broadly classified into polyether polyols and polyester polyols. Polyether polyol is a compound obtained by addition polymerization of alkylene oxide such as propylene oxide and ethylene oxide to a low molecular compound having two or more hydroxyl groups in the molecule such as glycol, glycerin, sorbitol, sucrose and the like. The polyester polyol is a compound in which a dibasic acid such as adipic acid and a polyhydric alcohol such as ethylene glycol are condensed to have a terminal hydroxyl group.

  The mixing ratio of isocyanate and polyol is not particularly limited. These mixing ratios are appropriately selected depending on the desired foamed state, heat insulating properties, and ease of production. A Lewis acid or a Lewis base may be added as a catalyst used for the reaction between the isocyanate and the polyol.

  Polyurethane may be foamed using a foaming agent. For foaming polyurethane, a method using carbon dioxide obtained by reaction of isocyanate and water is widely used. However, the density of the polyurethane can be further reduced by using a foaming agent. As the blowing agent, it is preferable to use hydrofluorocarbon (HFC), hydrocarbons (pentanes), and carbon dioxide rather than chlorofluorocarbons that are strictly regulated.

  Next, the manufacturing method of the heat insulating material 1 which concerns on this embodiment is demonstrated. The manufacturing method of the heat insulating material 1 has the process of filling an isocyanate and a polyol inside the frame member which has a bottom face part and a side part, and the process of arrange | positioning a plant piece inside a frame member. ing. Further, the production method includes a step of producing a polyurethane by reacting an isocyanate with a polyol under normal pressure or reduced pressure.

  As shown in FIG. 6, the frame member 10 that can be used in the manufacturing method of the present embodiment is not particularly limited as long as it has a bottom surface portion 11 and a side surface portion 12 for forming the shape of the heat insulating material 1. That is, it is not limited to the rectangular parallelepiped frame member 10 as shown in FIG. 6, and can have any shape for obtaining the desired heat insulating material 1. Moreover, when making the surface of the heat insulating material 1 into a curved surface instead of a plane, it is set as the shape from which the frame member 10 can also obtain a curved surface shape according to it. The frame member 10 can be appropriately selected depending on the size of the heat insulating material 1 to be formed and the amount of polyurethane.

  As for frame member 10, it is preferred that some surfaces of bottom face part 11 and side face part 12 are removable. Thereby, it becomes easy to release the molded heat insulating material 1 from the frame member 10.

  Here, when the rectangular parallelepiped heat insulating material 1 as shown in FIG. 1 is formed, the frame member 10 has a bottom surface portion 11 consisting of one surface and a side surface portion 12 consisting of four surfaces. However, the ceiling part facing the bottom face part 11 is arbitrarily set. When the ceiling is provided on the frame member 10 and the plant pieces and the polyurethane raw material are completely sealed inside the frame member 10, foaming of polyurethane cannot proceed because the foamed polyurethane is pressed by the ceiling. In this case, since polyurethane foam becomes insufficient, the density of the obtained polyurethane increases, and the heat insulating performance of the heat insulating material decreases. Therefore, when providing a ceiling part so that polyurethane foaming progresses, it is preferable to open part of the ceiling part to facilitate the polyurethane foaming. Moreover, foaming of polyurethane can be advanced toward the open part by reducing the pressure from a part of the open part. In addition, when shape | molding the rectangular parallelepiped heat insulating material 1, since the foam 2 exposed from the open part cannot become a plane easily, it is preferable to make it a plane by cutting.

  In the manufacturing method of this embodiment, such a frame member 10 is filled with an isocyanate and a polyol. The method of filling the frame member 10 with isocyanate and polyol is not particularly limited, and can be performed by any method depending on the type and amount of raw materials used, the shape of the heat insulating material 1, and the like.

  Here, generally as a manufacturing method of a polyurethane foam board, there exist a slab method (block method), a continuous lamination method, a sandwich panel method, an injection method, etc. Further, when it is not necessary to form a polyurethane foam plate into a plate shape, there is a spray method in which a mixture of isocyanate and polyol is directly sprayed and adhered to a portion to be insulated. In the manufacturing method of the present embodiment, the method of filling the frame member 10 with isocyanate and polyol is preferably performed by a slab method or an injection method.

  The slab method is a method in which a polyurethane raw material is poured into the frame member and then the raw material is foam-cured. In the slab method, since the internal pressure is increased by foaming, it is necessary to select a material constituting the frame member that is not deformed by the internal pressure. In addition, when the heat insulating material obtained after foaming is formed by cutting, paper or a plastic film may be used as the frame member 10. In addition, when a material that easily reacts with isocyanate or polyol, for example, a material having many hydroxyl groups such as wood, is used for the frame member 10, a release agent having a good release property is applied, or a sheet having a release property is used. It is preferable to paste. Thus, by improving mold release property, the obtained heat insulating material 1 can be easily released from the frame member 10.

  The injection method is a method in which a polyurethane raw material is injected into the inside of the frame member while being pressurized and is integrally molded with the frame member by foaming and curing. Even when such an injection method is used, the frame member 10 can be efficiently filled with an isocyanate and a polyol as in the slab method.

  Furthermore, the manufacturing method of this embodiment has the process of arrange | positioning the plant piece 3 in the inside of the frame member 10. FIG. The arrangement | positioning aspect of the plant piece 3 is not specifically limited, As shown in FIG. 1, you may make it the several plant piece 3 orientate to one direction, and as shown in FIG. You may make it do. Moreover, it is not limited to such an aspect, You may arrange | position the plant piece 3 at random so that it may not orient in a fixed direction inside the frame member 10. FIG.

  In addition, the process of arrange | positioning the plant piece 3 in the inside of the frame member 10 may be before the process of filling the above-mentioned isocyanate and polyol, and may be after. That is, first, the plant piece 3 may be disposed after filling the inside of the frame member 10 with the isocyanate and the polyol. Conversely, after the plant piece 3 is disposed inside the frame member 10, the isocyanate and the polyol are disposed. And may be filled. However, in the case where the plant piece 3 is disposed after filling the inside of the frame member 10 with the isocyanate and the polyol, the plant piece 3 is disposed before the foaming starts after the isocyanate reacts with the polyol. Is preferred.

  In this embodiment, it is preferable to fill the isocyanate and the polyol after disposing the plant piece 3 inside the frame member 10. In this case, polyurethane foam growth proceeds toward the opening of the frame member 10 and does not proceed toward the bottom surface 11 or the side surface 12. Therefore, when the isocyanate and the polyol are filled in a portion away from the opening of the frame member 10, the polyurethane foam 2 is filled in the entire voids of the plant piece 3, which is preferable.

  And after filling the inside of the frame member 10 with isocyanate and a polyol and arrange | positioning the plant piece 3 further, isocyanate and polyol are made to react under a normal pressure or pressure reduction, and a polyurethane is produced | generated. By reacting an isocyanate with a polyol under normal pressure or reduced pressure and polymerizing polyurethane, the foam of the polyurethane grows through the voids between the plant pieces. And since the plant pieces are adhere | attached by the polyurethane which maintained the low density by filling the space | gap between plant pieces with the foam of polyurethane, the heat insulating material 1 which was able to obtain both heat insulation and intensity | strength can be obtained. .

  In addition, the pressure condition at the time of reaction of isocyanate and polyol will not be specifically limited if it is the normal pressure which is a pressure equal to atmospheric pressure, or the pressure reduction which is a pressure lower than atmospheric pressure. From the viewpoint that no special equipment is required, the reaction is preferably carried out at normal pressure. Moreover, when the space | gap between plant pieces 3 is narrow and the space | gap of the plant piece 3 cannot fully be filled with the foam 2 at normal pressure, it is preferable to make it react under reduced pressure.

  In the production method of the present embodiment, a pressurized atmosphere is not generated during the reaction between the isocyanate and the polyol. Even when the frame member 10 is provided with a ceiling, the isocyanate and polyol and the plant piece 3 are hermetically sealed so that polyurethane foam is not inhibited by the ceiling. If the polyurethane is molded while being pressurized in the polyurethane foaming stage, the polyurethane swells with the deformation of the plant piece 3. At this time, polyurethane foam may not be crushed or foam growth may not spread due to the deformation pressure of the plant pieces. In this case, in the obtained heat insulating material, since the density of polyurethane and plant pieces increases, there is a possibility that the thermal conductivity is increased and the heat insulating property is lowered.

And after foaming by reaction of isocyanate and polyol is completed, the heat insulating material 1 of this embodiment can be obtained by releasing the composite body of the foam 2 and the plant piece 3 from the frame member 10. FIG. . In addition, you may use as the heat insulating material 1 in the state which the said composite_body | complex and the frame member 10 joined, without releasing the composite_body | complex of the foam 2 and the plant piece 3 from the frame member 10. FIG. And as above-mentioned, it is preferable that the density of the polyurethane which is the foam 2 obtained under a normal pressure or pressure reduction is 0.1 g / cm < ³ > or less. When the density of the polyurethane is such a value, the heat insulating property of the polyurethane is improved, so that the heat insulating property of the whole heat insulating material can be improved.

  In this embodiment, it is preferable to use a hemp stalk core wood part as the plant piece 3 of the heat insulating material 1. “Hemp stalk core woody part” means an elongated core obtained by removing the bast from the hemp. Since the hemp bast is usually high in density and low in heat insulation, the core is often used. In this embodiment, the hemp stalk core woody part can be oriented in one direction by utilizing its length, shape and the like without crushing the hemp woody part. Thus, when the plant piece 3 is comprised by the hemp stalk core wood part, the heat insulating material 1 which is low density and lightweight, and has the intensity | strength which can be used practically can be obtained. Further, unlike the conventional heat insulating material using hemp as a raw material, there is no need for a step of pulverizing the wood part of hemp or a step of defibrating the bast portion of hemp. Therefore, the manufacturing process of the heat insulating material 1 can be simplified, and the productivity of the heat insulating material 1 is excellent. Further, since the hemp wood part is used without being crushed, an adhesive for adhering the crushed material is not required, and the hemp stalk core wood part can be adhered only by the foam 2.

  Thus, the manufacturing method of the heat insulating material 1 according to the present embodiment includes the step of filling the frame member 10 having the bottom surface portion 11 and the side surface portion 12 with the isocyanate and the polyol, and the inside of the frame member 10. And a step of disposing the plant piece 3. Further, the production method includes a step of producing a polyurethane by reacting an isocyanate and a polyol under normal pressure or reduced pressure. And the foamed polyurethane produces | generates inside the frame member 10 by reaction of isocyanate and a polyol, and the plant pieces 3 are adhere | attached by the said polyurethane. According to the manufacturing method of the present embodiment, the space between the plant pieces 3 is filled with the polyurethane foam 2, so that the compression step between the plant pieces and the adhesive is not necessary. Therefore, the obtained heat insulating material has a low density, and high heat insulating properties can be obtained. Moreover, since the polyurethane and the plant piece 3 are formed without applying pressure, the plant piece 3 is not deformed and fixed. Therefore, even when moisture enters the obtained heat insulating material 1, the expansion of the heat insulating material 1 is suppressed, and the dimensional stability is increased. Furthermore, since the plant piece 3 is adhered by the polyurethane foam 2, sufficient strength as a heat insulating material can be obtained.

  In addition, as a method of improving the heat insulation property of a heat insulating material, there are two methods: (1) a method for selecting a porous plant piece, that is, a method having a low specific gravity, and (2) a method for adjusting the gap between plant pieces. It is done. In the production method of the present embodiment, since a pressurized atmosphere is not generated during the reaction between the isocyanate and the polyol, the increase in the density of the plant pieces is suppressed even when a porous plant piece is used, and the heat insulating property is reduced. Can be increased. Moreover, as above-mentioned, in the inside of a heat insulating material, a plant piece may be oriented in one direction and may be orthogonally oriented. Further, the shape of the plant piece is not particularly limited, and can be any shape. Therefore, it becomes possible to adjust the space | gap between plant pieces and to improve heat insulation more.

  Hereinafter, the present embodiment will be described in more detail with reference to examples and comparative examples, but the present embodiment is not limited to these examples.

[Example 1]
First, a plywood having a thickness of 9 mm was used, and a frame member having an internal size of 20 cm in length, 20 cm in width, and 3 cm in height and having no ceiling portion was produced. Furthermore, Chuko Chemical Industries Co., Ltd. Chuko flow fabric FGF-500-6 was affixed inside the frame member as a release sheet.

Next, a Japanese cedar strand was oriented in one direction as a plant piece inside the frame member. The strand has a length of 200 mm, a length of 5 mm, a width of 3 mm, and a density of 500 kg / m ³ .

  As a polyurethane raw material, a water foaming urethane foam system (isocyanate main component liquid: product number 14HX032, polyol main component solution: product number 14RD033) manufactured by Sumika Covestro Urethane Co., Ltd. is used. Mixed. At this time, 124 parts by mass of the isocyanate main component liquid was mixed with 100 parts by mass of the polyol main component liquid. And before the liquid mixture of a polyol main component liquid and an isocyanate main component liquid became cream form, the said liquid mixture was poured into the back | inner side opposite to the opening part of a frame member, and was made to react with a normal pressure. At this time, the mixed solution reacted and foamed, but the plant pieces were fixed so as not to float.

  After leaving for 10 minutes until foaming of the mixed solution was completed, the heat insulating material of this example having a thickness of 3 cm was obtained by removing from the frame member. In addition, the weight ratio of a plant piece and a polyurethane foam in the heat insulating material after shaping | molding was 88:12.

[Example 2]
The heat insulation of this example was carried out in the same manner as in Example 1 except that the strands as plant pieces were arranged in an orthogonal orientation, and the weight ratio of the molded plant pieces to polyurethane foam was 5:95. I got the material.

[Example 3]
First, the same frame member as Example 1 was produced, and the release sheet was affixed inside. Next, inside the frame member, a stem core strand of Bangladesh jute having an outer diameter of about 1 cm was arranged as a plant piece in one direction.

  Further, as a polyurethane raw material, an HFC foamed urethane foam system manufactured by Soflanwiz Co., Ltd. (isocyanate main component liquid: product number MIC, polyol main component solution: product number 469-95IK) was used. Were mixed. At this time, 100 parts by mass of the isocyanate main component liquid was mixed with 100 parts by mass of the polyol main component liquid.

  And before the liquid mixture of a polyol main component liquid and an isocyanate main component liquid became cream form, the said liquid mixture was poured into the back | inner side opposite to the opening part of a frame member. After pouring the mixed solution, the mixed solution and the plant pieces were allowed to stand in the desiccator together with the frame member, and the inside of the desiccator was further reduced to 500 hPa using a suction pump. At this time, the mixed solution reacted and foamed in a reduced-pressure atmosphere, but the plant pieces were fixed so as not to float.

  After leaving for 10 minutes until foaming of the mixed solution was completed, the heat insulating material of this example having a thickness of 3 cm was obtained by removing from the frame member. In addition, the weight ratio of a plant piece and a polyurethane foam in the heat insulating material after shaping | molding was 75:25.

[Example 4]
As a plant piece, a stem core strand of a Bangladeshi jute having an outer diameter of about 1 cm was vertically cut and cut so that the cross section became 1/8. Further, the molded plant pieces and the polyurethane foam were molded at normal pressure so that the weight ratio of the polyurethane foam was 50:50. Except this, it carried out similarly to Example 3, and obtained the heat insulating material of this example.

[Example 5]
As the plant piece, a Thai bagasse stalk core strand chipped with a slicer was used. Furthermore, the strands made into chips were arranged so as to be aligned in one direction so that the length directions were aligned. Further, the molded plant piece and polyurethane foam were molded so as to have a weight ratio of 75:25 and molded at 500 hPa. Except this, it carried out similarly to Example 3, and obtained the heat insulating material of this example.

[Example 6]
As the plant piece, a stem core strand of Bangladesh kenaf having an outer diameter of about 2 cm was cut vertically and the cross section was cut to 1/8. Further, the chopped strands were arranged so as to be orthogonally oriented. Further, the molded plant pieces and polyurethane foam were molded so that the weight ratio thereof was 60:40 and normal pressure. Except this, it carried out similarly to Example 3, and obtained the heat insulating material of this example.

[Comparative Example 1]
A heat insulating material of this example was obtained in the same manner as in Example 1 except that no plant piece was used.

[Comparative Example 2]
A heat insulating material of this example was obtained in the same manner as in Example 3 except that the plant pieces were not used and the molding was performed at normal pressure.

[Comparative Example 3]
A commercially available polystyrene foam heat insulating material having a density of 30 kg / m ³ was used as the heat insulating material of this example. The polystyrene foam heat insulating material is formed by an extrusion method.

[Comparative Example 4]
A commercially available softwood plywood having a density of 540 kg / m ³ was used as a heat insulating material in this example as a plant board.

[Comparative Example 5]
As a plant board, a commercially available particle board having a density of 750 kg / m ³ was used as a heat insulating material in this example.

[Comparative Example 6]
As a plant board, a commercially available wood fiber heat insulating material having a density of 50 kg / m ³ was used as the heat insulating material of this example.

  In the heat insulating materials obtained in Examples 1 to 6 and Comparative Examples 1 and 2, the type and orientation of plant pieces, the type and amount of polyurethane raw material, the atmospheric pressure during molding, and the plant pieces and polyurethane foam after molding Table 1 shows the weight ratio.

[Evaluation]
About the heat insulating material obtained by the Example and the comparative example, the density and the bending strength were measured along Japanese Industrial Standard JIS A9521 (heat insulating material for construction). Moreover, about the said heat insulating material, using a thermal conductivity measuring apparatus, along JIS A1412-2 (The measuring method of the thermal resistance and thermal conductivity of a thermal insulating material-2nd part: Heat flow meter method (HFM method)), The thermal conductivity was measured. The measurement results are shown in Table 2.

  As shown in Table 2, since Example 1 added many cedar long strips having a relatively high density, the bending strength was improved and the strength approaching the particle board of Comparative Example 5 could be obtained. . Moreover, the value of thermal conductivity became smaller than the general plant-type board like the comparative examples 4 and 5, and it had high heat insulation.

  On the other hand, as in Comparative Examples 4 and 5, since the general plant-based board is molded by compression, it has high strength, but the thermal conductivity is large, so that the heat insulation is insufficient. .

In Example 2, the amount of cedar long strips added was reduced compared to Example 1, and the density of the polyurethane foam part was made 100 kg / m ³ or less to make a composite. Therefore, Example 2 had a heat conductivity as small as 26 mW / mK, and had a very high heat insulating property that entered the E section in the heat conductivity classification of the heat insulating material by the Housing Finance Support Organization. Moreover, the bending strength became 3 times or more compared with the comparative example 1 which does not add a cedar long strip.

On the other hand, Comparative Example 1 had a thermal conductivity as small as 25 mW / mK, and had a very high thermal insulation property that entered the E category in the thermal conductivity category of the heat insulating material by the Housing Finance Support Organization. However, Comparative Example 1 had a bending strength of 30 N / cm ² and did not have a high strength.

In Example 3, since the voids between the plant pieces were narrow and the foaming growth was poor, a jute stem core having a density of 200 kg / m ³ or less was compounded by molding under reduced pressure. Therefore, the bending strength was about three times that of Comparative Example 2. Furthermore, the value of thermal conductivity was 38 mW / mK, and the heat insulating properties were equivalent to those of Comparative Examples 3 and 6. Thus, it was found that the heat insulating material of Example 3 can achieve both strength and heat insulating properties.

  Moreover, from Example 4, it turned out that high intensity | strength and heat insulation can be made compatible by shredding | judging a jute stem core and making it composite. Further, Examples 5 and 6 also have high heat insulation properties that fall into the C category in the thermal conductivity category of the heat insulating material by the Housing Finance Support Organization, and are significantly stronger than the foam heat insulating materials as in Comparative Examples 1 and 2. It was found that it can be high.

In Comparative Example 2, the heat conductivity was 30 mW / mK, and it had high heat insulation properties that entered the E section in the heat conductivity classification of the heat insulating material by the Housing Finance Support Organization. However, Comparative Example 2 had a bending strength of 120 N / cm ² and did not have a high strength. In addition, as in Comparative Examples 3 and 6, other types of heat insulating materials have a thermal conductivity of 38 to 40 mW / mK, and have high heat insulating properties that fall into the C category in the thermal conductivity classification of the insulating materials by the Housing Finance Support Organization. Was. However, Comparative Examples 3 and 6 had a bending strength of 25 N / cm ² or less and did not have high strength.

  As mentioned above, although this embodiment was demonstrated by the Example and the comparative example, this embodiment is not limited to these, A various deformation | transformation is possible within the range of the summary of this embodiment. That is, in the heat insulating material 1 shown in FIG. 1, the gap between the plant pieces 3 is filled with the foam 2, and the periphery of the plant piece 3 is covered with the foam 2. However, the present embodiment is not limited to such an aspect. For example, in the heat insulating material 1, only a part of the plant piece 3 may be covered with the foam 2, and the plant pieces 3 may be in direct contact with each other.

1 Insulation 2 Foam (Polyurethane)
3,3A plant piece 10 frame member 11 bottom surface portion 12 side surface portion

Claims (4)

Filling the interior of a frame member having a bottom surface portion and a side surface portion with an isocyanate and a polyol;
Disposing plant pieces inside the frame member;
Reacting the isocyanate with the polyol under normal or reduced pressure to produce polyurethane;
Have
A method for producing a heat insulating material, in which foamed polyurethane is generated inside the frame member by a reaction between the isocyanate and the polyol, and the plant pieces are bonded to each other by the polyurethane.   The said plant piece is a manufacturing method of the heat insulating material of Claim 1 which is at least 1 stem core chosen from the group which consists of jute, kenaf, and bagasse.   The manufacturing method of the heat insulating material of Claim 1 or 2 whose specific gravity of the said plant piece is 0.2 or less. The manufacturing method of the heat insulating material as described in any one of Claims 1 thru | or 3 whose density of the said polyurethane is 0.1 g / cm < ³ > or less.

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