Composite material, filament for 3D printer using the same, and manufacturing method of composite material

Abstract

To provide a composite material in which an odor contained therein is remarkably reduced while being inexpensive and having high practicability, and to provide a filament for a 3D printer using the same.SOLUTION: A composite material contains a thermoplastic resin, a used paper material, and a deodorizer. The used paper material contains a fiber component derived from used paper and is dispersed in the thermoplastic resin. The deodorizer is an inorganic material having a low molecular weight, and reduces an odor generated by mixing the thermoplastic resin and the used paper material. The deodorizer is added in an amount of less than 3 mass%.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present embodiment relates to a composite material, a filament for a 3D printer using the same, and a method for manufacturing the composite material. [Background technology]

[0002] Conventionally, composite materials in which fibrous materials are added to thermoplastic resins are known (Patent Document 1). There is a demand for further expansion of the use of such composite materials from the viewpoints of utilizing natural biomass materials and reducing the amount of synthetic resin used. For example, when forming a composite material using pure pulp or cellulose, or carbon nanofibers (CNFs) derived from these, there is a problem that a large amount of carbon dioxide is emitted to purify the materials. In addition, these materials have a problem of being expensive because they are highly refined. Therefore, there is a demand for the use of inexpensive fibrous materials with a low degree of refinement, such as waste paper.

[0003] However, waste paper is derived from various types of paper, such as newspapers, cardboard, and miscellaneous paper. Therefore, it contains not only pure cellulose components, but also inorganic and organic substances such as ink and surface coating agents. The inorganic and organic substances contained in the waste paper are decomposed or denatured when mixed with thermoplastic resin. As a result, composite materials mixed with waste paper contain odorous components unique to the waste paper, and there is a problem that they produce an odor that is intolerable for practical use. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2003-326556 A Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, the objective is to provide an inexpensive and highly practical composite material that significantly reduces the odor it contains, and a filament for 3D printers that uses the same. Another object of the present invention is to provide a method for producing a highly practical composite material, which can reduce odors significantly through simple steps. [Means for solving the problem]

[0006] The composite material according to one embodiment includes a deodorant. When waste paper is mixed with a thermoplastic resin, the thermoplastic resin and the waste paper are heated to melt the thermoplastic resin. Therefore, the organic matter contained in the waste paper decomposes or denatures, generating malodorous components. The malodorous components are generated from the composite material produced, and cause a deterioration in the quality of the composite material. In the case of the composite material according to one embodiment, by adding a deodorant to the thermoplastic resin and waste paper to be mixed, the malodorous components generated by heating are further decomposed and absorbed by the deodorant. Therefore, the malodorous components generated from the composite material produced are significantly reduced. Also, even when waste paper is used as the fiber material, purification of the waste paper is not necessary. Therefore, the odor contained can be significantly reduced, and the product can be produced at a low cost and with high practicality.

[0007] In addition, in one embodiment of the composite material manufacturing method, a premix is ​​produced by mixing waste paper material with a deodorant. As a result, even if waste paper material is added to a thermoplastic resin and heated, the malodorous components generated by heating are decomposed and absorbed by the deodorant. Therefore, the malodorous components generated from the composite material are reduced by the simple process of mixing the deodorant with the waste paper material. Therefore, the odor contained therein is significantly reduced by the simple process, and a highly practical composite material can be manufactured. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a photographic diagram showing an example of waste paper material mixed into a composite material according to one embodiment. [Diagram 2] Schematic diagram showing a gas chromatograph containing odors generated from a composite material that has not been treated for odor removal. [Diagram 3]Schematic diagram showing a process for manufacturing a composite material according to one embodiment. [Figure 4] Schematic diagram showing a process for manufacturing a composite material according to one embodiment. [Diagram 5] FIG. 1 is a schematic diagram showing test results of examples and comparative examples of a composite material according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the composite material will be described with reference to the drawings. The composite material includes a thermoplastic resin, waste paper, and a deodorant. The thermoplastic resin may be any of various resins that are commonly used. The thermoplastic resin may be, for example, a polyolefin such as polyethylene or polypropylene. In addition, the thermoplastic resin may be a general-purpose resin such as polystyrene resin or PET resin. The composite material may be molded into, for example, a wire or rod shape, and used as a filament for a 3D printer. The composite material may also be crushed into, for example, chips or pellets, and used as a material for resin molding.

[0010] The waste paper material contains fiber components derived from waste paper. The waste paper material is obtained, for example, by collecting paper consumed by households and businesses for the purpose of recycling. The collected waste paper is crushed after removing impurities other than paper components, such as resin and metal. The waste paper material is fine fibrous material that remains in a crusher when the waste paper is crushed, as shown in FIG. 1, and has an appearance similar to dust. Specifically, waste paper includes city-collected waste paper and industrial waste paper according to the Ministry of the Environment's "Basic Policy on Promoting the Procurement of Environmental Goods, etc." (revised Cabinet decision on February 24, 2023). City-collected waste paper is used paper generated, for example, from stores, offices, and homes, and is used as a raw material for paper to be reused by paper manufacturers. In this case, city-collected waste paper also includes paper that is shipped as a product and collected by producers after passing through the distribution stage. In addition, industrial waste paper is generated from the processing process after the papermaking process of the base paper, and is used as a raw material for paper to be reused by paper manufacturers. Thus, waste paper means, for example, newspapers, cardboard, miscellaneous paper, miscellaneous paper and beverage cartons.

[0011] The waste paper fibers contained in the waste paper material are mainly about 30 μm to 1500 μm in length. The waste paper fibers contained in the waste paper material are about 5 μm to 100 μm in width, and are mostly linear fibers with a large aspect ratio. The waste paper fibers include clumped fibers formed by the aggregation of linear fibers. Note that the waste paper material only needs to contain fibers derived mainly from waste paper, and may contain other fibers derived from new paper, for example, in addition to the waste paper fibers.

[0012] The deodorant is an inorganic deodorant of a low molecular weight inorganic system. The deodorant is provided as a powder. The deodorant is added in an amount of less than 3 mass% based on the total weight of the composite material. The deodorant is particularly effective in deodorizing when added in an amount of about 0.1 mass%. Of the inorganic deodorants, the deodorant is preferably titanium oxide or a mixture containing titanium oxide. As an example, the deodorant may be titanium oxide, a mixture of zeolite and titanium oxide, or the like.

[0013] A composite material in which waste paper is added to a thermoplastic resin generates odorous components derived from the waste paper. Waste paper includes waste paper derived from old newspapers and miscellaneous paper that have been printed or coated. In this way, inorganic and organic substances contained in inks and coatings during printing are denatured or decomposed by heating when mixed with a thermoplastic resin. In particular, organic substances generate odorous components when oxidized by heating. Odorous components that cause such bad odors include alcohols, aldehydes, esters, carboxylic acids, and phenols. Examples of aldehydes include epoxydecenal, vanillin, nonanal, and nonanal. Examples of esters include lactones. Examples of carboxylic acids include butyric acid, valeric acid, and dodecanoic acid. Examples of phenols include propylphenol, ethylphenol, and cresol.

[0014] A dispersant may be added to the composite material. The dispersant promotes uniform dispersion of various additives such as waste paper and deodorants in the thermoplastic resin. The dispersant may be a commercially available one such as "UMEX 1010" manufactured by Sanyo Chemical Industries, Ltd. The dispersant is preferably added in a small amount of 1 mass % or less of the overall composition of the composite material.

[0015] The composite material generates an odor derived from waste paper. Examples of odors that are sensual to humans include the waste paper odor and cigarette odor peculiar to waste paper, and the bad odors caused by the odor components exemplified above. In this embodiment, the deodorant is added to the thermoplastic resin and waste paper material to reduce the bad odors caused by the waste paper odor, cigarette odor, and odor components. As an example, FIG. 2 shows the results of a gas chromatograph of a comparative example of a composite material containing waste paper that does not contain a deodorant. When comparing the gas chromatograph shown in FIG. 2 with the sensory olfactory sense, the bad odors sensed by the olfactory sense were detected in the areas A1, A2, A3, and A4 in FIG. 2. Of these, A1 is an odor mainly caused by hexanal. A2 is an odor mainly caused by heptanal. A3 is an odor mainly caused by hexanoic acid. A4 is an odor mainly caused by 3-hydroxypyridine and 5-hydroxymethyl-2-furaldehyde. Thus, unless a suitable deodorizing treatment is applied to a composite material containing recycled paper, the composite material will emit an odor due to the recycled paper.

[0016] The gas chromatographic analysis was performed as follows. The analyzer used was Shimadzu Corporation's GCMS QP-2010plus. The column used was ZB-WAX (length 30 m, inner diameter 0.25 mm, film thickness 0.25 μm). The temperature conditions were 40°C for 5 minutes, followed by heating at 10°C per minute and holding at 230°C for 10 minutes. The gas pressure was 200 kPa. The sampling conditions were as follows: powders of the composite material examples and comparative examples were placed in a dedicated container, the temperature was adjusted to 200°C for 10 minutes, and the gas in the container was sampled. Figure 2 shows the results of the gas chromatographic analysis performed under the above conditions.

[0017] Next, a method for producing a composite material will be described with reference to FIGS. Either the manufacturing method A shown in FIG. 3 or the manufacturing method B shown in FIG. 4 can be selected arbitrarily based on the compositions of the thermoplastic resin, deodorant, waste paper material, and dispersant selected.

[0018] (Manufacturing method A) As shown in FIG. 3, in manufacturing method A, the thermoplastic resin and the deodorant are mixed while being heated (S101). In this case, the thermoplastic resin and the deodorant are mixed, for example, using a plastomill, at 200° C. for about 1 minute. Waste paper is added to the mixture obtained by this mixing (S102). The mixture and the waste paper are further mixed at 200° C. for about 10 minutes. The resulting final mixture is molded into any shape, such as a line or pellet (S103). The final mixture may also be molded into any final shape, for example, by injection in a molten state.

[0019] (Manufacturing method B) As shown in Fig. 4, in manufacturing method B, the waste paper material and the deodorant are mixed in advance to produce a premixture (S201). As described above, the waste paper material is a fibrous aggregate, and the deodorant is a powder. Therefore, the waste paper material and the deodorant are easily mixed into a premixture by dry mixing.

[0020] The premix is ​​mixed with a thermoplastic resin (S202). At this time, the thermoplastic resin is melted to a degree that it has flowability by heating, for example, to about 200°C. The premix is ​​added to the softened thermoplastic resin and kneaded with the thermoplastic resin. In this way, the premix and the thermoplastic resin are mixed, and a final mixture is generated in which the waste paper material and the deodorant are dispersed in the thermoplastic resin. The generated final mixture is molded into any shape, such as a line or pellet shape (S203). The final mixture may also be molded into any final shape, for example, by injection in a molten state.

[0021] Examples and comparative examples will be described below. As shown in FIG. 5, samples 1 to 9 were prepared and subjected to sensory odor testing. The odors were examined for the presence or absence of unpleasant odors, such as waste paper odor, tobacco odor, and other unpleasant odors. Unpleasant odors are odors that are different from waste paper odor or tobacco odor but are perceived as unpleasant to the sense of smell. The odors were evaluated based on the odor remaining after 3 days (72 hours) had passed since the preparation of each sample. "○" indicates that the odor was reduced and there was no odor, or that a faint odor that was not noticeable remained. "△" indicates that the odor was reduced but a clear odor remained. "X" indicates that there was no reduction in odor.

[0022] The examples and comparative examples were manufactured by the above-mentioned "manufacturing method A" or "manufacturing method B", and the odor was confirmed. To confirm the odor, the final product was formed into a sheet and then crushed into particles with a particle size of about 3 to 5 mm. The crushed particles were sealed in an aluminum pack with a volume of about 200 ml. The particles to be sealed were 50 g. The odor was confirmed by opening the aluminum pack after a predetermined period of time had passed. Polypropylene (PL500A manufactured by SunAllomer Co., Ltd.) was used as the thermoplastic resin.

[0023] (Sample 1) Sample 1 is a comparative example. Sample 1 contains polypropylene and recycled paper. Sample 1 does not contain any deodorant or other ingredients. Sample 1 was prepared by manufacturing method A. When the odor was checked, it was confirmed that Sample 1 had a recycled paper odor. It is believed that since no deodorant was added to Sample 1, the recycled paper odor could not be reduced.

[0024] (Sample 2) Sample 2 is a comparative example. Sample 2 contains polypropylene and recycled paper. Sample 2 does not contain any deodorant or other ingredients. Sample 2 was prepared by manufacturing method B. When the odor was checked, it was confirmed that Sample 2 had a recycled paper odor. It is believed that since no deodorant was added to Sample 2, the recycled paper odor could not be reduced. Furthermore, a comparison with Sample 1 shows that the difference in manufacturing method does not affect the reduction of the recycled paper odor.

[0025] (Sample 3) Sample 3 is a comparative example. Sample 3 contains polypropylene and recycled paper. Aminoguanidine hydrochloride, an organic low molecular weight deodorant, was added to Sample 3 as a deodorant. Sample 3 was prepared by manufacturing method A. When the odor was checked, Sample 3 had a reduced recycled paper odor, but a cigarette odor was confirmed. It can be seen that Sample 3 reduces the recycled paper odor with the deodorant, but a different odor can be confirmed. This is thought to be due to either or both of the effect of the deodorant masking the recycled paper odor and the interaction between the deodorant and trace components contained in the recycled paper.

[0026] (Sample 4) Sample 4 is a comparative example. Sample 4 contains polypropylene and recycled paper. Sample 4 used "Elm Plus" manufactured by Elm Japan Co., Ltd. as an inorganic low molecular weight deodorant. This deodorant contains zeolite, zinc oxide, aluminum oxide, titanium oxide, etc. Sample 4 was prepared by manufacturing method A. In the case of Sample 4, 3 mass % of the deodorant was added. When the odor was checked, the recycled paper odor of Sample 4 was reduced, but not sufficiently.

[0027] (Sample 5) Sample 5 is a comparative example. Sample 5 contains polypropylene and recycled paper. The same inorganic low molecular weight deodorant as Sample 4 was added to Sample 5. Sample 5 was prepared by manufacturing method B. In the case of Sample 5, 3 mass% of the deodorant was added. When the odor was checked, the recycled paper odor of Sample 5 was reduced, but not sufficiently. Furthermore, a comparison with Sample 4 shows that the difference in manufacturing method does not affect the reduction of the recycled paper odor.

[0028] (Sample 6) Sample 6 is a comparative example. Sample 6 contains polypropylene and waste paper. For Sample 6, "VSC-MB" manufactured by Japan Antibacterial Research Institute, Furukawa Sangyo Kaisha, Ltd., and Alba Finetech Co., Ltd. was used as the deodorant. This deodorant has the function of decomposing volatile sulfur compounds that cause malodor, and is capable of deodorizing various malodor components. Sample 6 was prepared by manufacturing method A. In the case of Sample 6, 3% by mass of the deodorant was added. When the odor was checked, the waste paper odor of Sample 6 was reduced, but not sufficiently.

[0029] (Sample 7) Sample 7 is a comparative example. Sample 7 contains polypropylene and waste paper. Sample 7 uses "AMT100" manufactured by Teika Co., Ltd. as an inorganic low molecular weight deodorant. This deodorant contains titanium oxide fine particles as the main component. Sample 7 was prepared by manufacturing method A. In the case of Sample 7, 3 mass% of the deodorant was added. When the odor was confirmed, Sample 7 reduced the waste paper odor, but an unpleasant odor different from both the waste paper odor and the tobacco odor occurred. It can be seen that Sample 7 reduces the waste paper odor by the deodorant, but a different odor is confirmed. This is thought to be due to either the effect of masking the waste paper odor by the deodorant or the interaction between the trace components contained in the waste paper and the deodorant, or both.

[0030] (Sample 8) Sample 8 is an example. Sample 8 contains polypropylene and recycled paper. Sample 8 contains "UMEX 1010" as a dispersant, and "AMT100" as an inorganic low molecular weight deodorant, as with sample 7. Sample 8 was prepared by manufacturing method B because a dispersant was added. In the case of sample 8, 0.1 mass% of the deodorant was added. When the odor was checked, the old paper odor was reduced in sample 8. In addition, no unpleasant odor different from the old paper odor or cigarette odor was confirmed in sample 8. Thus, it can be seen that sample 8, which is an example, can reduce the old paper odor by using an appropriate amount of deodorant, in comparison with sample 7.

[0031] (Sample 9) Sample 9 is an example. Sample 9 contains polypropylene and recycled paper. Sample 9 does not contain a dispersant, but contains titanium oxide, an inorganic low molecular weight deodorant. Sample 9 was prepared by manufacturing method B for comparison with Sample 8. Sample 9 contained 0.1% by mass of deodorant. When the odor was checked, the recycled paper odor was reduced in Sample 9. In addition, no unpleasant odor different from the recycled paper odor or cigarette odor was confirmed in Sample 9. Thus, it can be seen that Sample 9, which is an example, reduces the recycled paper odor with an appropriate amount of deodorant. It can also be seen that the addition of a dispersant does not affect the reduction of the recycled paper odor.

[0032] As described above, the composite material according to the present embodiment contains a deodorant. As a result, the malodorous components generated by heating are decomposed and absorbed by the deodorant. Therefore, the malodorous components generated from the generated composite material are significantly reduced. Furthermore, even when waste paper is used as the fiber material, purification of the waste paper is not required. Therefore, the odor contained can be significantly reduced, and the product can be inexpensive and highly practical.

[0033] In one embodiment, the composite material is made of waste paper, which accounts for approximately 50% by mass of the thermoplastic resin. This reduces the consumption of thermoplastic resin derived from petroleum, and promotes the reuse of collected waste paper. The composite material is used as a substitute for thermoplastic resin by mixing waste paper with the thermoplastic resin and adding an appropriate amount of deodorant. This allows for effective use of resources without increasing the amount of energy input.

[0034] Furthermore, in one embodiment of the composite material manufacturing method, a premix is ​​produced by mixing waste paper material with a deodorant. As a result, even if waste paper material is added to a thermoplastic resin and heated, the malodorous components generated by heating are decomposed and absorbed by the deodorant. Therefore, the malodorous components generated from the composite material are reduced by the simple process of mixing the deodorant with the waste paper material. Therefore, the odor contained therein is significantly reduced by the simple process, and a highly practical composite material can be manufactured.

[0035] The present invention described above is not limited to the above-described embodiment, and can be applied to various embodiments without departing from the gist of the invention.

Claims

1. A thermoplastic resin; A waste paper material containing a fiber component derived from waste paper and dispersed in the thermoplastic resin; a deodorizing agent of less than 3% by mass, which is a low molecular weight inorganic material and reduces odors generated by mixing the thermoplastic resin with the waste paper material; Including, Composite material.

2. The deodorant is titanium oxide or a mixture containing titanium oxide. The composite material of claim 1.

3. A composite material according to claim 1 or 2, Filament for 3D printers.

4. A first mixing stage in which a waste paper material containing a fiber component derived from waste paper is mixed with an inorganic deodorant to generate a premixture; a second mixing stage in which the premix produced in the first mixing stage is mixed with a thermoplastic resin while heating to produce a final mixture in which the premix is ​​dispersed in the thermoplastic resin; A method for producing a composite material comprising the steps of:

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