WO2000005049A1 - Fiber-reinforced plastic and denture base made therefrom - Google Patents

Abstract

A fiber-reinforced plastic characterized in that it comprises a synthetic resin being harmless to ecotope and a silk fiber added thereto in a specific ratio and dispersed therein, and a denture base characterized in that it is made from a fiber-reinforced plastic comprising a synthetic resin being harmless to ecotope and a silk fiber added thereto in a specific ratio and dispersed therein. In the aforementioned fiber-reinforced plastic, the synthetic resin is selected from among methyl methacrylate resin, polyethylene and polypropylene. It is suitable that the silk fabric is used in a form selected from among a powdery fine splinter, a raw yarn, a twisting yarn and a combination thereof. These fiber-reinforced plastic and denture base manufactured therefrom exhibit good properties such as high strength and also have highly adaptable capacity to ecotope.

Description

 WO 00/05049-I-PCT / JP99 / 03901

Akira Title of the invention Fiber-reinforced plastic and its denture base

Technical field

 The present invention relates to a fiber-reinforced plastic having high strength and a high adaptability to an ecological environment such as a human body and nature, and a denture base formed of the fiber-reinforced plastic.

Background art

 In modern society, plastic products are distributed in every corner of everyday life due to their convenience, and they continue to be consumed in large quantities, and living without plastic is enjoying the benefits of being inconceivable. However, in recent years, while some plastics have high convenience, they have gradually started to be recognized as having dangerous harmful effects, which has become a social problem.

 Historically, plastics originally used as plastics were polyethylene (PE) and polypropylene (PP), which had little toxicity, burned relatively cleanly when discarded and burned, and had some utility Was something. Then polyethylene

Recognizing that (PE) and polypropylene (PP) have problems with strength, etc., improved plastics such as polyvinyl chloride (PVC) made from ethylene and chlorine, polycarbonate (PC), Properties such as sulphone (PSF) with dramatically improved properties such as strength have been born and are up to the present day.

 However, plastics made of organochlorine compounds such as polyvinyl chloride (PVC) can produce dioxins due to the high temperature during incineration and chlorine contained in the plastics when they are incinerated after production and consumption. There is. Dioxin has two toxicities, acute toxicity and chronic toxicity, and exhibits chronic toxicity such as carcinogenicity and teratogenicity due to long-term ingestion of low concentrations of dioxin. For example, it is well known that dioxin is also contained in the defoliants used during the Vietnam War, and many malformed babies were born after the end of the war, and cancer patients occurred.

 In addition, dioxin, polycarbonate (PC) and polysulfone

Bisphenol A (bis — A), which constitutes (PSF), and vinyl chloride and plasticizer It has been pointed out that phthalic acid compounds, such as phthalic acid esters, added as an environmental hormone (endocrine disrupting chemicals) that affect the endocrine function of living organisms such as the human body. It has been recognized that such endocrine disruptors inhibit the normal growth of living cells and have a great adverse effect on the human body and the natural environment.Ecology is caused by dioxin generated during incineration and bisphenol A eluted. There is concern about the impact on the environment.

 Therefore, with the increasing awareness of the impact on the ecological environment in recent years, the newly provided plastics include conventional plastics such as polyvinyl chloride (PVC) and polycarbonate (PC). It is highly desired that the material has a high degree of adaptability to the ecological environment while maintaining its strength and other characteristics, and that it can protect the global environment and maintain the health of the human body.

 The above requirements are particularly strong for plastics used directly on the human body, such as denture bases. However, conventional denture base materials are made of polycarbonate resin 素材 sulfone resin, and polyvinyl chloride is used to further strengthen the strength. Was sometimes mixed. Polycarbonate, polychlorinated chloride, and the like are plastics having the above-mentioned risks, and there is a strong concern that leaving the current state of the denture base on the human body would be serious.

Disclosure of the invention

 The present invention has been made in view of the above problems, and has excellent characteristics such as high strength, has high adaptability to an ecological environment, and aims to preserve the global environment and maintain human health. An object of the present invention is to provide a fiber-reinforced plastic capable of performing the above-mentioned steps, and a denture base made of the fiber-reinforced plastic. The fiber-reinforced plastic and the denture base of the present invention have no danger of producing chemical substances harmful to the ecological environment, such as dioxins and environmental hormones (endogenous disrupting chemicals) generated during waste incineration, and have high strength. It exhibits a high function with such characteristics.

The fiber-reinforced plastic according to the present invention is characterized in that a predetermined percentage of silk fiber is dispersed and added to a synthetic resin harmless to the ecological environment. In the above fiber-reinforced plastic, the synthetic resin is any one of methyl methacrylate resin, polyethylene, and polypropylene, and the silk fiber is a powdery fine piece, a raw yarn shape, and a twisted yarn shape. It is preferable to use any one of these or a combination thereof.

 Further, the denture base according to the present invention is characterized by being formed of a fiber-reinforced plastic in which a predetermined ratio of silk is dispersed and added to a synthetic resin harmless to the ecological environment. Also in this case, when the synthetic resin is any one of methyl methacrylate resin, polyethylene, and polypropylene, and the silk fiber is any one of powdery fine crushed pieces, raw yarn shape, twisted yarn shape, or a combination thereof. It is suitable.

 The above-mentioned fiber-reinforced plastic and its denture base are made of synthetic resin that is harmless to the ecological environment, and silk fiber, which is a natural material, is added. It has a high degree of adaptability to safety and is safe.

 For example, when the base material is a methyl methacrylate resin, polyethylene, polypropylene, etc., it has the same or higher strength as the organochlorine compound and does not generate dioxin when incinerated and does not leak environmental hormones. Does not adversely affect the human body or natural environment. In particular, the fiber-reinforced plastic using a methyl methacrylate resin as a base material has a high strength, and the fiber-reinforced material is inconspicuous and has a high aesthetic property, and is most suitable as a material directly used for a human body such as a denture base. The fiber-reinforced plastic and the denture base of the present invention have the following advantages in detail.

 ①Improvement of strength enables creation of new products and improvement of product value. Ordinary methyl methacrylate resin (PMMA), polyethylene (PE), polypropylene

Products with strength that could not be realized by (PP) etc. can be manufactured.

 (2) It is harmless and useful because it is made of silk and a base material that does not generate harmful substances. For example, vinyl chloride (PVC) leaks the toxicity contained in water or hot water, but the above fiber-reinforced plastic does not have such toxicity. It can be applied to a variety of products that touch the baby's skin or carry it into the mouth, protecting the safety of users. Examples of products include toothbrushes, dishes, toys, and water-washing appliances.

(3) Silk fiber as a reinforcing material does not impair the aesthetics of products made of this fiber-reinforced plastic. Superior aesthetics compared to products using glass fiber or carbon fiber, because the mixed reinforcing material has a transparent feeling and does not affect the aesthetics of the product ing.

 ④Especially for materials that are used directly on the human body, such as denture bases placed in the mouth, it is essential that the materials have high strength and are not toxic.These conditions must be satisfied. This fiber-reinforced plastic, which has a positive effect on the human body through its pharmacological action against skin diseases, is optimal.

BRIEF DESCRIPTION OF THE FIGURES

 Figure 1 is an explanatory diagram showing the silk fiber structure,

 FIG. 2 is a cross-sectional view showing the structure of sericin,

 Fig. 3 (a) is a partial perspective view showing a cotton-like 1.0 denier raw silk, Fig. 3 (b) is a partial perspective view showing a two-ply 27 denier silk, and Fig. 3 (c). ) Is a partial perspective view showing silk with 4 strands of 29 denier, FIG. 3 (d) is a partial perspective view showing silk with 32 deniers of 6 strands, and FIG. 4 is a methyl methacrylate resin (or polypropylene). FIG.

 FIG. 5 is an explanatory view showing a test piece of polyethylene,

 Fig. 6 is a graph showing the relationship between the mixing weight ratio of the finely ground powdered silk and the bending stress at the maximum load when the base material is methyl methacrylate resin.

 FIG. 7 is a graph showing the relationship between the mixing weight ratio of the cotton denier 1.0 denier silk and the bending stress at the maximum load when the base material is methyl methacrylate resin,

 Fig. 8 is a graph showing the relationship between the mixing weight ratio of two-ply 27 denier silk and the bending stress at maximum load when methyl methacrylate is used as the base material.

 Fig. 9 is a graph showing the relationship between the mixing weight ratio of 4-strand 29 denier silk and the bending stress at the maximum load when methyl methacrylate resin is used as the base material.

 Fig. 10 is a graph showing the relationship between the mixing weight ratio of 6-ply 32 denier silk and the bending stress at the maximum load when the base material is methyl methacrylate resin,

 Fig. 11 is a graph showing the relationship between the mixing weight ratio of each added silk and the bending stress at the maximum load when the base material is methyl methacrylate resin,

Fig. 12 is a graph showing the relationship between the mixing weight ratio of the finely ground powdered silk and the tensile stress at maximum load when polyethylene is used as the base material. Fig. 13 is a graph showing the relationship between the mixed weight ratio of cotton denier 1.0 denier silk and the tensile stress at the maximum load when the base material is polyethylene,

 Fig. 14 is a graph showing the relationship between the mixed weight ratio of two-ply 27 denier silk and the tensile stress at the maximum load when polyethylene is used as the base material.

 Fig. 15 is a graph showing the relationship between the mixed weight ratio of 4-denier 29-denier silk and the tensile stress at maximum load when polyethylene is used as the base material.

 Fig. 16 is a graph showing the relationship between the mixed weight ratio of 6-denier 32 denier silk and the tensile stress at maximum load when polyethylene is used as the base material.

 Fig. 17 is a graph showing the relationship between the mixing weight ratio of each added silk and the tensile stress at maximum load when polyethylene is used as the base material.

 Fig. 18 is a graph showing the relationship between specimen elongation at maximum load and tensile stress at maximum load when the base material is polyethylene,

 Fig. 19 is a graph showing the relationship between the mixing weight ratio of the finely ground crushed silk and the bending stress at the maximum load when polypropylene is used as the base material.

 Fig. 20 is a graph showing the relationship between the mixing weight ratio of denier silk and the bending stress at the maximum load when the base material is polypropylene, 1.0.

 Figure 21 is a graph showing the relationship between the mixed weight ratio of two-ply 27 denier silk and the bending stress at maximum load when polypropylene is used as the base material.

 Fig. 22 is a graph showing the relationship between the mixed weight ratio of 4-denier 29-denier silk and the bending stress at maximum load when the base material is polypropylene.

 Figure 23 is a graph showing the relationship between the mixed weight ratio of 6-denier 32 denier silk and the bending stress at maximum load when polypropylene is used as the base material.

 Fig. 24 is a graph showing the relationship between the mixing weight ratio of each added silk and the bending stress at the maximum load when polypropylene is used as the base material.

 Figure 25 is a schematic diagram of the anti-fracture test,

 Fig. 26 is a graph showing the analysis results according to the amount of silk added to the composite plastic when the added silk is powdery fine crushed pieces.

Fig. 27 is a graph showing the analysis results according to the amount of silk added to the composite plastic when the added silk is a cotton denier 1.0 denier. Fig. 28 is a graph showing the analysis results according to the amount of silk added to the composite plastic when the added silk is 2 burns and 27 denier,

 Fig. 29 is a graph showing the analysis results according to the amount of silk added to the composite plastic when the added silk is four strands and 29 denier.

 Fig. 30 is a graph showing the analysis results according to the amount of silk added to the composite plastic when the added silk is 6 strands and 32 deniers.

 Fig. 31 is a graph showing the analysis results according to the silk shape when the added amount of silk is 0.1g (mixing weight ratio 0.55%).

 Fig. 32 is a graph showing the analysis results according to the silk shape when the added amount of silk is 0.4 g (mixing weight ratio 2.2%).

 FIG. 33 is a graph showing the analysis results according to the silk shape when the added amount of silk was 0.8 g (mixing weight ratio 4.4%).

BEST MODE FOR CARRYING OUT THE INVENTION

 Embodiments of a fiber-reinforced plastic and a denture base thereof according to the present invention will be described based on examples, but the present invention is not limited to the following embodiments and examples. In particular, the synthetic resin used for the fiber-reinforced plastic and its denture base is not limited to those shown in the examples, but any synthetic resin that is harmless to the ecological environment is appropriate. Also, the shape, thickness, length, and mixing weight ratio of the silk fibers to be dispersed and added to the fiber-reinforced plastic are not limited to those shown in the examples but may be any values within the scope of the present invention. This also includes the case where a substance containing is added.

 As a premise, the characteristics and characteristics of the fiber reinforced plastic of the present invention and the silk fiber mixed and added to the denture base will be described. Silk uses silkworms to release the protein produced by the silkworm itself from the spinneret into yarn. The cross-sectional shape of the silk fiber and the chemical structure of the protein are complex. It is a factor that causes it to occur.

FIG. 1 is an explanatory view showing the silk fiber structure, and FIG. 2 is a cross-sectional view showing the structure of sericin. As shown in FIG. 1, the silk fiber structure is such that one fiber 3 is formed in a shape in which two fiber-in-fibres 1 are wrapped around a sericin 2 having a quality of nickel. One fiber in-fiber 1 has a thickness of 0.2 to 0.2 consisting of fiber-in molecule 1a. The spiral microfibrils 1b in 4ii are bundled into about 900 to 140,000 microfibrils 1b, which are fibrils 1c, which are the basic structural units constituting fibers. Is composed.

 The sericin 2 wrapping the fibroin fiber 1 has a layered structure as shown in Fig. 2 when it is enlarged, and the I layer 2a of sericin 2 from the outside, the mixed layer 2b of the I layer 2a and the Π layer 2c, 6It has a six-layer structure of layer 2c, IE layer 2d, IV layer 2e, and V layer 2f. Each layer 2a to 2 2 of sericin 2 has characteristics in each layer and the entire 6 layers, and all of them are important for silk fiber. For example, in order to protect the living body inside the cocoon, it works to protect the inside in response to changes in the outside air and changes in the external environment.

Here, the characteristics of silk fiber compared with other natural fibers are shown. Table 1 compares the properties of silk and other natural fibers. In Table 1, d: denier, the unit of Young's modulus g / d, is a unit indicating the thickness of the fiber. One denier is obtained when 450 m of fiber weighs 5 O mg. In terms of the unit of impact cutting energy E erg / cm ² , the erg is the work that is performed when a force of 1 dyn acts on an object and the point of action moves 1 cm in the direction of the force.

As shown in Table 1, compared to cotton and wool, silk fiber has a higher Young's modulus and It has high impact shear energy, is durable, has a high decomposition temperature due to heat, and has excellent heat resistance.Silk fiber has overall properties compared to other natural fibers. Are better. Synthetic fiber decomposes, melts and burns at around 200 ° C to generate toxic gas, while silk fiber burns at 300 to 400 ° C and does not generate toxic gas. Excellent in strength, safety and cost. Furthermore, even when added to the base material, it has high permeability and does not cause turbidity, etc., and rarely causes a change in the color tone, color, etc. of the base material. High fiber reinforced plastics can be produced.

 Furthermore, silk fibers not only have properties such as high strength, but also have a positive effect on the ecological environment such as the human body. In other words, silk fibers have long been regarded as important because of their beauty, good touch, etc., and their usefulness has been recognized.In modern times, however, sericin, a silk mantle, is effective for mucous membrane diseases and skin diseases. Its pharmacological effects have been scientifically demonstrated, and it can be said to be the optimal “environmental material” as a material directly applied to the human body. Silk fibroin also has good compatibility with living organisms and is optimal as a biomaterial. The shape and thickness of the silk fibers added to the synthetic resin of the base material in the experimental examples described later are as follows: powdery finely crushed pieces (thickness of lmm or less), cotton-like 1.0 denier yarn (thickness) Approximately 10 //), 2 twists 27 denier twisted yarn (thickness of about 270 / Z), 4 burns 29 denier twisted yarn (thickness of about 290), 6 twisted 3 2 There are five types of denier twisted yarn (thickness of about 320). The length of the silk was 2 strands of 27 denier, 4 strands of 29 denier, and 6 strands of 32 denier. The appropriate length was at least mm. Fig. 3 shows the shape of the silk other than the powdery fine crushed pieces. Fig. 3 (a) is a partial perspective view showing a silk fiber which is a cotton-like 1.0 denier raw yarn, and Fig. 3 (b) is a partial perspective view showing a silk fiber which is a two-burn 27 denier twisted yarn. (C) is a partial perspective view showing a silk fiber that is a four-ply 29 denier twisted yarn, and (d) is a partial perspective view that shows a six-burned 32 denier twisted silk fiber. FIG.

 Hereinafter, examples of the fiber-reinforced plastic in which the above-described five types of silk fibers are mixed and added to a synthetic resin serving as a base material and a denture base thereof will be described.

[Example 1] Test pieces of fiber reinforced plastic are made of methyl methacrylate resin (PMMA) as a base material of synthetic resin, powdered fine crushed pieces, cottony 1.0 denier raw yarn, 2 twisted 27 denier twisted yarn, 4 Twenty-nine denier twisted yarn and six-ply 32 denier twisted yarn were manufactured by dispersing and adding each of five types of silk fibers to the above-mentioned methyl methacrylate resin (18.0 g). The test specimens are molded to standard dimensions and shapes according to JIS K7203 (hard plastic bending test). Fig. 4 is an explanatory view showing the manufactured test piece of methyl methacrylate resin.The test piece is finished in a rectangular shape of 110 mm X 10 mm X 4 mm, which is the specified size and shape of the test piece of JIS K7203. ing.

 The dispersion in the methyl methacrylate resin · The amount of the silk fiber to be added · The mixing weight ratio is as shown in Table 2. In addition, since the flocculent 1.0 denier yarn is bulky, the mixing amount and the mixing weight ratio are set to 1/10 with respect to the mixing amount and the mixing weight ratio of other silks.

 Table 2

In producing the test piece, a prototype of an aluminum plate having a thickness of 4 _mm , a length of 110 mm, and a width of 21 mm was produced, and plaster was packed in a mold serving as a mold, and the prototype was buried. You. The mold of the mold can be divided into two parts later.

Place the center of the thickness of the (prototype) and immerse it in gypsum in two upper and lower parts. Separating material is applied to the plaster on the lower surface which is pre-cured so that the upper and lower gypsum are separated from the plaster of the mold to be buried.

(Synthetic neutral detergent) is applied. After the gypsum has hardened, the upper and lower molds and gypsum are separated and the original aluminum plate is removed. The gypsum mold for producing test pieces in the above process is completed. On the inner surface of the finished gypsum mold, a sodium alginate-based separating material should be applied as a separating material between the test piece material and the gypsum, and dried sufficiently.

The methyl methacrylate resin, which is the base material of the test specimen, is manufactured from polymer powder and monomer liquid. The composition of the polymer powder is fine powder PMMA (polymethylmethacrylate acrylate polymer) 99.0 to 99.3%, benzoyl peroxide (polymerization initiator) 0.2 to 0.5%, coloring agent 0.5%, the composition of the monomer liquid is MMA (monomethyl methacrylate · monomer) 84-100%, EDMA (ethylene glycol dimethacrylate · crosslinking agent) 0 ~ 16%, and 0.005% of hydroquinone (polymerization inhibitor). In producing the test piece of this example, Isole Resin H manufactured by Hydental Japan Co., Ltd. was used.

When 180 g of the polymer powder is mixed with 77.4 ml of the monomer liquid, a rice cake-like prepolymerization stage starts after about 15 minutes at room temperature 23. Pre-sufficient plasticity The plaster mold divided into upper and lower parts in the polymerization stage is evenly filled up and down. During this time, each type of silk aligned in the longitudinal direction is placed in the long axis direction of the test specimen (110 mm direction). In parallel at a predetermined weight ratio. The silk fibers of the crushed pieces are mixed in advance in the polymer powder. After that, the gypsum mold is put together through a polyethylene film and subjected to a test pressure at a pressure of 5 kgf / cm ³ , and after the test pressure, the gypsum mold is divided to remove excess filler. After that, the gypsum molds are joined together without the intermediary of a polyethylene film, bonded under the same pressure as the test pressure, heat-polymerized by dry polymerization, heated at 100 ° C for about 15 minutes, and then gradually cooled to obtain a test piece material. Take out. After completion of the polymerization, the test piece material is cut into a specified size to complete the test piece. The test pieces obtained in the above manufacturing process were subjected to an anti-fracture test by JIS K7203 (bending test of hard plastic). The test equipment used was an Instron type universal testing machine · Shimadzu AG-5000A (owned by Shiga Prefectural Industrial Testing Laboratory). Min, the test indenter was 20.000 KGF, and the distance between fulcrums was 80.000 mm. An anti-fracture test was performed under the above set conditions, and four test pieces were tested for each silk mixing condition to obtain data (one of them could not be tested). For comparison, data was also obtained from test pieces of methyl methacrylate resin and polysulfone resin without silk. Tables 3 to 7 show the maximum load value (bending stress value) by the anti-fracture test for each silk mixing condition. Maximum load value in the table

The unit of (bending stress value) is MPa. Table 3

Table 4 Addition of flocculent 1.0 fiber yarn and mixing ratio

 Methyl methacrylate resin 0.055% 0.22% 0.44% 15% Test piece (No.)

 1 83.602 93.026 86.534

 2 77.796 90.780 86.180

 3 63.400 70.245 80.748

 4 70.127 84.063 87.838

 Comparative Example 1 (methacrylic acid

 Chill resin, no silk added) 63.751

 Comparative Example 2 (Borisulfone

95.782 (resin, no silk)

Table 5

Table 6

4 strands 29 '::-

 Methyl methacrylate resin 0.55% 2JZ% 4.4% 15% Example of test piece (No.)

 1 74.609 81.425

 2 74.727 84.875 82.278

 3 58.319 82.875 81.346

 4 65.401 78.630 101528

 Comparative Example 1 (methacrylic acid

 Chilled fat and silk-free) 63.751

 Comparative Example 2 (Polysulfone

95.782 (no fat or silk)

Table 7

The test results in Tables 3 to 7 above are shown in the graphs. Fig. 6 is a graph showing the relationship between the mixed weight ratio of the powdered finely divided silk and the bending stress at the maximum load. Fig. 7 is the mixed weight ratio of the cotton denier 1.0 denier silk and the bending stress at the maximum load. Fig. 8 is a graph showing the relationship between the mixed weight ratio of two strands of 27 denier silk and the bending stress at the maximum load. Fig. 9 is a graph showing the relationship between the mixed weight ratio of four strands and 29 denier silk. Fig. 10 is a graph showing the relationship between the bending stress at the maximum load, Fig. 10 is a graph showing the relationship between the mixing weight ratio of 6-denier 32 denier silk and the bending stress at the maximum load, and Fig. 11 is a fine powder fragment. 2 burning

3 is a graph showing the relationship between the mixing weight ratio of each added silk of 27 denier, 4 strands, 29 denier, and 6 strands of 32 denier and the bending stress at the maximum load. In Figs. 6 to 11, the dashed line indicates the bending stress of the methyl methacrylate resin without the addition of silk, and the dashed line indicates the bending stress of the polysulfone resin.

 Judging from the test results shown in Figs. 6 to 11, the methyl methacrylate resin to which silk fiber was added has improved bending stress and increased strength compared to the methyl methacrylate resin to which no silk was added. ing. In particular, when four types of cotton denier 1.0 denier, twin twisted 27 denier twisted yarn, four twisted 29 denier twisted yarn, and six-burned 32 denier twisted yarn are mixed, no silk shown in Fig. 11 is used. As shown in the area above the added methyl methacrylate resin (dashed-dotted line), the strength increases reliably and significantly, up to 59.

The strength was improved by 3% of bending stress, confirming the effectiveness of the fiber-reinforced plastic to which silk fibers were added. In addition, the mixing weight ratio of silk fiber is 2. When the content was 2% or more, the improvement in strength was more remarkable in each case.

 As the mixing weight ratio of the added silk fiber increases to 0.55%, 2.2%, and 4.4%, the strength increases, and strength by bending stress comparable to that of polysulfone resin is obtained. As shown in Fig. 10, when the mixing weight ratio of 6-burn 32 denier twisted yarn is 15%, the strength tends to be lower than at 4.4%. When methyl resin is used as the base material, it is considered that the optimum mixing weight ratio of silk exists between 4.4% and 15% for 6-denier 32 denier twisted yarn. Another tendency is that the larger the thickness of the added silk fiber, the higher the strength due to bending stress and the stability of the test data, and when the cotton yarn is 1.0 denier, the mixing amount is different. Despite being 110 compared to the added silk fiber, remarkable improvement in strength due to bending stress was confirmed.

 [Example 2]

 The test piece of fiber reinforced plastic uses polyethylene (PE) as the base material of synthetic resin, powdered fine crushed pieces, cottony 1.0 denier raw yarn, 2 twisted 27 denier twisted yarn, 4 burned 29 denier Twenty-five types of silk fibers, a twisted yarn and six burned 32 denier twisted yarns, were mixed with 4.0 g of the polyethylene described above, respectively, to produce the yarn. The test pieces are molded to the standard size and shape according to JIS K7113 (Plastic tensile test method) No. 2 test piece. Fig. 5 is an explanatory diagram showing a test piece of polyethylene.The test piece has the specified dimensions and shape specified in JIS K7113, and has a total length of A115mm, both end widths B25 ± 1mm, and a parallel portion length C3. 3 ± 2 mm, width of parallel part D 6 ± 0.4 mm, small radius E 14 ± lmm, large radius F 25 5 mm 2 mm, distance between marking lines G 25 ± 1 mm, distance between grips H 80 ± 5 mm, thickness I 1-3 mm.

Table 8 shows the mixing amount and mixing weight ratio of silk fiber mixed with polyethylene as the base material. The fluffy 1.0 denier yarn is bulky, so that the mixing amount and mixing weight ratio are 1/10 with respect to the mixing weight ratio of other silk fibers. Table 8

In manufacturing the test piece, a mold that is divided into a concave surface and a smooth surface in advance is manufactured. Novatec LL film grade UF240 (manufactured by Nippon Polychem Co., Ltd.) is used for polyethylene as a base material of the test piece. The UF 2 4 characteristics 0 MFR (degree of flowability) 2. l gZ l O min, density ^{0. 9 2 0 g / cm 3} (LDPE ( linear low density polyethylene)), mp (melting ends Point) 124 ° C, softening temperature 100, no additive.

Pellet of base metal 4.Prepare Og and silk fiber adjusted to the specified weight ratio according to the longitudinal dimension and shape of the test piece.Some of the pellet of the base metal is placed on the concave surface of the mold. Dissolve evenly in an electric furnace at 140 ° C, and press with a spatula (spatula) to eliminate bubbles. Then, the silk is dispersed and added in the longitudinal direction. The silk should be added so that the silk is distributed evenly over the entire length A: 115 mm of the test piece based on the length of the parallel part C: 33 mm in Fig. 5. After that, after coating the remaining pellets, it is melted again in an electric furnace at 140 ° C, and the base material dissolved with the spatula is adapted to the silk fibers. After that, the combined molds are pressed at a pressure of 5 kgf / cm ³ , and then pressed and gradually cooled, and then adjusted to specified dimensions and shapes, such as removal of excess parts, to complete the test specimen.

A tensile test was performed on the test piece obtained in the above manufacturing process by JIS K7113 (plastic tensile test method). The test equipment used is a universal tensile strength tester (5 t) INSTRON 5569 (owned by the Tohoku Industrial Center in Shiga Prefecture). The test conditions are: test form tension, crosshead speed 20.000 mm / min, full-scale load range The load range was 50 kg (the load range changed because a part of the test piece exceeded the load range: 5000 kg), and the distance between the grips of the test piece was 80 mm. A tensile test was conducted under the above set conditions, and the tensile stress (MPa) at the maximum load and the elongation (mm) of the test piece at the maximum load were determined for each silk mixing condition. Data and similar data were obtained using a polyethylene test piece without silk as a control. Tables 9 to 13 show the tensile stress data (MPa) at the maximum load by the tensile test for each silk mixing condition, and Table 1 shows the corresponding test piece elongation (mm) data at the maximum load. 4 to Table 18 are shown.

 Table 9

 Mixing ratio of poly with powdered fine crushed pieces

 Example of ethylene experiment (No.) 0.55% 2.2% 4.4% 15%

 1 14.112 8.757 8.895

2 6.796 8.904 8.620

 3 8.630 8.600 8.748

 Four

 Comparative Example 1 (Polyethylene

 Without silk) 19.172

 Comparative Example 2 (") 17.868

 Comparative Example 3 (") 17.897 Table 10

 Add 1.0% cotton fiber and mix ratio

 Experimental example of polyethylene (N 0.055% 0.22% 0.44% 15% o.)

 1 14.131 15.700 15.123

 2 12.523 12.984 12.327

 Three

 Four

 Comparative Example 1 (polyethylene

 Without silk) 19.172

 Comparative Example 2 ("> 17.868

Comparative Example 3 (") 17.897 Two strands of 27 tails added and mixing ratio

Experimental example of polyethylene (N 0.55% 2.2% 4.4% 15% 0.)

 1 17.436 12.798 21.290

2 14.994 25.703 28.360

3 32.323

 4 18.064

Comparative Example 1 (Polyethylene ''

Without silk) 19.172

Comparative Example 2 (〃) 17.868

Comparative Example 3 (") 17.897 Table 1 2

 4-strand 29 ';:-

Example of polyethylene (N 0.55% 2.2% 4.4% 15% o.)

 1 18.054 21.075 34.000

2 14.877 16.955 30.783

3 32.117

4 28.165 Comparative Example 1 (Polyethylene

Without silk) 19.172

Comparative Example 2 (〃) 17.868

Comparative Example 3 (17.897

Table 13

 6 strands 32 liters are added and mixing ratio

Of polyethylene (N 055% 2.2% 4.4% 15% o.)

 1 15.945 35.020 40227 61.928

2 14.955 30.028 37.343 29.243

3 32.136 64.871 34.568

4 33.617 38.648 41.521

5 58.673 Comparative Example 1 (Polyethylene

Without silk) 19.172

Comparative Example 2 (17.868

Comparative Example 3 (17.897 Table 14

Example of ethylene experiment (No.) 0.55% 2.2% 4.4% 15%

 1 240.083 22.843 25.658

2 4.833 90.414 10.500

 3 10.196 11.833 20.272

Four

Comparative Example 1 (Polyethylene ''

330.322

Comparative Example 2 (/ ') 314.035

Comparative Example 3 (") 298.675

Table 15 5 Fluffy 1.0 tail yarn added and mixing ratio

 Po M's: Test example (M 0.055% 0.22% 0.44% 15% υ.

 1 256.112 266.688 276.758

2 235561 232.583 224.255

Three

 Four

Comparative Example 1 (Polyethylene

No silk added> 330.322

Comparative Example 2 (") 314.035

Comparative Example 3 (") 298.675 Table 16

 2 strands 27'-neil added and mixing ratio

Experimental example of polyethylene (た 0.55% 2.2% 4.4% 15% ο.)

 1 313 ^ 83 7.167 4.095

2 285.605 5.647 7.667

3 7.409

 4 7.833

Comparative Example 1 (Polyethylene ''

330.322

Comparative Example 2 (") 314.035

Comparative Example 3 (") 298.675

Table 17

The test results for the tensile stress (MPa) at the maximum load in Tables 9 to 13 above are shown in the graph. Fig. 12 is a graph showing the relationship between the mixing weight ratio of the finely ground powdered silk and the tensile stress at the maximum load, and Fig. 13 is the mixing weight ratio of the cotton denier 1.0 denier silk and the tensile stress at the maximum load. Fig. 14 is a graph showing the relationship between the mixed weight ratio of two strands of 27 denier silk and the tensile stress at maximum load, and Fig. 15 is a graph showing the mixed weight of four strands of 29 denier silk. Fig. 16 is a graph showing the relationship between the ratio and the tensile stress at the maximum load. Fig. 16 is a graph showing the relationship between the mixed weight ratio of 6-denier 32 denier silk and the tensile stress at the maximum load. Fig. 17 is a fine powder fragment. , 2 burns, 27 denier, 4 burns, 29 denier, 6 twists, 3 2 denier It is a graph which shows the relationship with tension stress. In FIGS. 12 to 17, broken lines, dashed-dotted lines, and two-dot dashed lines indicate the tensile stress at the maximum load of the polyethylene resin without silk. Examining Figs. 12 to 17, two-ply 27-denier twisted yarn, four-twisted 29-denier twisted yarn, six-ply twisted 32-denier twisted yarn, fiber-reinforced plastics with increasing amount of silk fiber added sequentially The strength with respect to the tensile stress of the yarn increased remarkably, and the strength with respect to the tensile stress particularly increased in the case of the 6-burn 32 denier twisted yarn.

 Furthermore, the correspondence between the tensile stress (Mpa) at the maximum load shown in Tables 9 to 13 above and the specimen elongation (mm) at the maximum load shown in Tables 14 to 18 above was obtained. Figure 18 shows the graph. In Fig. 18, 粉 indicates powdered finely crushed silk, ◎ indicates cottony 1.0 denier raw silk, mouth has two twisted 27 denier twisted silk, △ indicates four twisted 29 denier silk. , 讕 shows the test results for 6-ply 32 denier twisted silk, and ◊ shows the test results for polyethylene without added silk.

 Examining Fig. 18, it can be seen that in the case of polyethylene without silk, the elongation (displacement) of the test piece is about 300 mm or more when the tensile stress (MPa) at the maximum load is applied. In the case of added polyethylene, the elongation of the test piece shifts to a range of 10 mm or less when the tensile stress at the maximum load is applied. This tendency is observed from 2.2% or more of the two-ply 27 denier twisted yarn, 2.2% or more of the 4-twisted 29 denier twisted yarn, and 0.5% or more of the 6-twisted 32 denier twisted yarn. Twist 27 4.4% or more of 27-denier twisted yarn, 4 burns 29% or more of 29-denier twisted yarn, 6-twisted 32 2.2% or more of 2-denier twisted yarn, the strength with respect to tensile stress is dramatically increased. At the same time, the elongation of the specimen under the maximum load is suppressed to 11 mm or less. Therefore, it is recognized that the addition of the silk fiber is effective in improving the strength of the fiber reinforced plastic, and that the strength of the fiber reinforced plastic is improved particularly with an increase in the thickness and the amount of the silk fiber.

 [Example 3]

The test piece of fiber reinforced plastic is made of polypropylene (PP) as the base material of synthetic resin, powdered fine frame, cotton-like 1.0 denier raw yarn, 2-twisted 27 denier twisted yarn, 4-twisted 29 denier Twisted yarns, 6 strands 3 5 types of silk fibers of 2 denier twisted yarns, Each was mixed with 4.1 g of the polypropylene to produce a mixture. The test specimens were prepared in standard dimensions and shapes according to JIS K7203 (plastic bending test method). FIG. 5 is an explanatory view showing a test piece of polypropylene. The test piece is finished in a rectangular shape of 110 mm X 10 mm X 4 mm with a specified size and shape of JIS K7203.

 Table 19 shows the mixing amount and mixing weight ratio of silk fiber mixed with the base material polypropylene. Note that the fluffy 1.0 denier yarn is bulky, so the mixing amount is set to 1/10 with respect to the mixing weight ratio of other silk fibers.

 Table 19

 In manufacturing the test piece, a mold that is made of a concave surface and that can be divided into two parts is manufactured in advance. Novatec PP injection molding grade MA03 (manufactured by Nippon Polychem Co., Ltd.) is used for polypropylene as the base material of the test piece. The characteristics of MA03 are: MFR (degree of flowability) 25 gZ10O, density 0.910 to 0.920 g / cm Melting point (end point of melting) 163 ° C It is.

Pellet of base metal 4.Prepare silk that has been adjusted to a predetermined weight ratio in accordance with the length and size of the test piece in the longitudinal direction and shape of the test piece, and the base material pellet becomes uniform when melted on the concave surface of the mold. Melt in an electric furnace at 165 ° C and press with a spatula (spatula) so that there are no air bubbles. Then, the silk was dispersed and added in parallel to the longitudinal direction of the test piece (direction of 110 mm) so as to be even, and the excess silk was cut off from the test piece and dissolved using a spatula. Let the wood adapt to the silk fibers. After that, the dies are combined and pressed under a pressure of 5 kgfcm ³ , and then the molded body is pressed and gradually cooled, then removed, and adjusted to the specified size and shape, such as removal of excess parts, to complete the test specimen.

The test pieces obtained in the above manufacturing process were subjected to an anti-fracture test according to JIS K7203 (hard plastic bending test method). The test equipment used was an Instron type universal testing machine, ORIENTEC RTC-1350A (owned by Shiga Prefectural Industrial Testing Laboratory). Test type SINGLE BEND (unidirectional bending test), test indenter moving speed 20.000mm / min, test indenter 20.000KGF, distance between fulcrums 80.000mm. An anti-fracture test was performed under the above set conditions, and data was obtained by testing four test pieces for each silk mixing condition. For comparison, data were also obtained from a polypropylene test piece without silk. Tables 20 to 24 show the maximum load value (bending stress value) by the anti-fracture test for each silk mixing condition. The unit of the maximum load value (bending stress value) in the table is MPa.

 Table 20

 Mixing ratio of poly with powdered crushed pieces

 Experimental example of propylene (N 0.55% 2.2% 4.4% 15% o.)

 1 40.532 37.479 45.496

 2 36.559 49.455 50.047

 3 49.859 50.873 32.219

 4 39.363 49.934 22.653

 Comparative Example 1 (Polypropylene

 • No silk added) 41.279

 Comparative Example 2 (") 42.185

 Comparative Example 3 ("> 44.885

 Comparative Example 4 <G) 37.507 Table 21 1 Fluffy 1.0-tail yarn added and mixing ratio

 0.055% 0.22% 0.44% 15%

 (No.)

 1 43.744 25.767 36,888

 2 45.721 39.564 31.055

 3 38.705 38.536 44.129

 4 37.972 43.693 30.092

 Comparative Example 1 (Polypropylene

 • Without silk) 41279

 Comparative Example 2 (42.185

 Comparative Example 3 (») 44.885

Comparative Example 4 (") 37 ^ 07 Table 2 2

 Add 27 'twin strand and mix ratio

0.55% 2.2% 4,4% 15% (No.)

 1 43.406 49.774 43.772

2 48.286 40.743 31.900

3 41.556 43.228 51.545

4 49.507 38.606 43.347 Comparative Example 1 (Polypropylene

 • No silk added) 41.279

Comparative Example 2 (> ') 42.185

Comparative Example 3 (> ') 44.885

Comparative Example 4 (〃) 37.507 Table 2 3

Add 4-twist 29 τ-rule and mix ratio

 Experimental example of reinforced polypropylene 0 ^ 5% 2.2% 4.4% 15% (No.)

 1 36.634 49.093 19.483

2 47.252 31.876 24.658

3 42.589 45.684 29.928

4 36.296 43.768 41.899 Comparative Example 1 (Polypropylene

 • No silk added) 41.279

 Comparative Example 2 (") 42.185

 Comparative Example 3 (") 44.885

Comparative Example 4 ("> 37.507

Table 2 4

The test results for the bending stress (MPa) at the maximum load in Tables 20 to 24 are shown in the graph. Fig. 19 is a graph showing the relationship between the mixing weight ratio of powdered finely crushed silk and the bending stress at the maximum load, and Fig. 20 is the mixing weight ratio of the cottony 1.0 denier silk and the bending stress at the maximum load. Fig. 21 is a graph showing the relationship between the mixed weight ratio of two strands of 27 denier silk and the bending stress under the maximum load, and Fig. 22 is the mixed weight ratio of four strands of 29 denier silk. Fig. 23 shows the relationship between the mixing weight ratio of 6-burner 32 denier silk and the bending stress at the maximum load, and Fig. 23 shows the relationship between the bending stress at the maximum load. 4 is a graph showing the relationship between the mixing weight ratio of each added silk of crushed pieces, two-ply twisted 27 denier, four-burned 29 denier, and six-burned 32 denier, and the bending stress at the maximum load. The broken, dashed-dotted, dashed-dotted and dashed-dotted lines in Figs. 19 to 24 indicate the bending stress at maximum load of polypropylene without the addition of silk.

Examining FIG. 24, it was confirmed that the fiber-reinforced plastic also improved in strength with respect to bending stress in the present example in which silk fibers were added to polypropylene. In particular, the strength was remarkably improved in the case of the 2-burnt 27-denier twisted yarn 4.4% and the 4-strand 29-denier twisted yarn 2.2%. When polypropylene is used as the base material, the effectiveness of the silk fiber addition in increasing the strength appears in the form of a gentle quadratic curve. You.

 [Example 4]

 In the present example, in order to verify the improvement of the strength of the fiber reinforced plastic from various viewpoints, a strength test was performed on various test pieces. The base material uses methyl methacrylate resin, a typical plastic that does not adversely affect the human body or the natural environment. Silk fiber is dispersed and added to this material to make fiber-reinforced plastic test specimens. As in the above-described embodiment, the test piece was prepared by considering the effect of the silk mixing state on the strength of the fiber-reinforced plastic, and experimentally changing the silk thickness, length, shape, etc., while changing the silk mixing amount ( (Or weight ratio).

 Specifically, a test piece was manufactured by dispersing and adding five types of silk fibers having dimensions suitable for the test piece to 18.0 g of methyl methacrylate resin as a base material. The shape of the silk fiber to be added is powdery crushed pieces (1 mm or less in raw yarn), cottony 1.0 denier raw yarn, 2 burns, 27 denier twisted yarn, 4 twisted 29 denier twisted yarn, 6 This burned 32 denier twisted yarn was uniformly mixed with the base material and pressed. Table 25 shows the mixing amount (mixing weight ratio) of silk. As a comparative object, a comparative test piece of polysulfone resin and methyl methacrylate resin without silk was manufactured, and the same experiment was tried on the comparative test piece.

 Table 25

The strength test of the test piece was performed by an anti-fracture test based on JIS K7203 (hard plastic bending test method) industrial standard. In order to carry out the bending test, the test piece was one in which the silk was uniformly dispersed and mixed in the base material as described above, and the cooling was completed. This was used as the standard size (11 O mm) specified in the bending test method. x 1 O mm X 4 mm), and manufactured according to the mixing weight ratio of each silk. The test facility is Shiga Industry The test condition (TEST MODE) was set to SINGLE BEND (unidirectional bending test) and the test indenter was moved using an Instron-type universal testing machine (Shimadzu AG-5000A), which is a test site-provided facility. The speed (TEST SPEED) was 20.000 mm / min, and the test indenter load (F / S LOAD) was 20.000 KGF (196.133N). Figure 25 shows a schematic diagram of the anti-fracture test.

 By performing the anti-fracture test, the following data on strength was obtained. From the stress-strain relationship based on this data, the material characteristics of the fiber-reinforced plastic are determined.

 ① Maximum value (MAX). These are the values when the maximum load is applied before the yield point where the elongation of the test piece, which is the material, begins to increase sharply without increasing the stress.

②Breakdown value (BREAK). The elongation starts to increase sharply without increasing the stress of the test piece. Each value after the yield point when the load is applied and the test piece is bent.

③ Maximum limit value (LOAD KGF). This is the load value when the stress of the test piece reaches a peak. Here, since the bending load is applied, it is the load of the bending strength of the test piece. The unit was N: Newton (1 kgf = 9.80665N).

 ④ Bending value (ELONG MM). The distance the indenter has moved, in mm.

⑤ Bending stress (STRESS KGF / MM ² ). The unit was expressed in terms of MPa (1MPa = 9.80665N).

 ⑥ Elongation value (STRA IN S). When a stress is generated by applying a load to the test piece, the molecules constituting the material of the test piece move and the test piece is deformed. The elongation value is the ratio of this amount of deformation (bending between the original test specimen plane and the deformed plane).

 The following is an example of an experiment in which a test piece was subjected to an anti-fracture test by changing the shape and amount of silk to be mixed and added. The base material of the test piece is a methyl methacrylate resin.

(Experiment No. 1) Table 26 shows the test results when 0.5 g (0.55%) of finely ground silk was added to 18.0 g of the base material. Table 26

(Experiment Νο · 2) Table 27 shows the test results when 0.4 g (2.2%) of fine powdered silk was added to 18.0 g of the base material.

 Table 27

(Experiment No.3) Table 28 shows the test results when 0.8 g (4.4%) of finely ground silk was added to 18.0 g of the base material.

 Table 28

(Experiment No.4) Table 2 9 shows the test results when 0.01 g (0.055%) of 1.0 denier cotton-like silk was added to 18.0 g of base material. Shown in Maximum value (MAX) Break value (BREAK) Maximum limit value / N (LOAD N) 114.120 110.031

 Bending value / book (ELONG MM) 17.698 17,715

 Bending stress / MPa (STRESS MPa) 83.602 82.523

 Elongation /% (STRAIN) 6.636 6.642

(Experiment No.5) Table 30 shows the test results when 1.0 g (0.22%) of silk, which is a 1.0 denier flocculent yarn, was added to 18.0 g of the base material. .

 Table 30

 Maximum value (MAX) Break value (BREAK) Maximum limit value / N (LOAD N) 124,035 123.878

 Bending value / Ran (ELONG MM) 12.897 12.913

 Bending stress / MPa (STRESS MPa) 93.026 92.909

 Elongation value (STRAIN) 4.836 6.642

(Experiment No. 6) Table 31 shows the test results when 0.8 g (0.44%) of silk, which is a 1.0 denier flocculent yarn, was added to 18.08 of the base material.

 Table 3 1

(Experiment No.7) Table 32 shows the test results when 0.1 g (0.55%) of 27 denier (double twist) silk was added to 18.0 g of base material. . Maximum value (MAX) Break value (BREAK) Maximum limit value / N (LOAD N) 114.748 106.245

 Bending value / m (ELONG MM) 19.430 22.993

 Bending stress / MPa (STRESS MPa) 86.063 79.684

 Elongation /% (STRAIN) 7.285 8.621

(Experiment No.8) Table 33 shows the test results when 0.4 g (2.2%) of 27 denier (two burning) silk was added to 18.0 g of base material. .

 Table 3 3

(Experiment No. 9) Table 34 shows the test results when 0.8 g (4.4%) of 27 denier (double twist) silk was added to 18.0 g of the base material.

 Table 34

(Experiment No.10) Table 35 shows the test results when 0.1 g (0.55%) of 29 denier (4-strand) silk was added to 18.0 g of base material. . Table 35

(Experiment No. ll) Table 36 shows the test results when 0.4 g (2.2%) of 29 denier (four strands) silk was added to 18.0 g of the base material.

 Table 3 6

(Experiment No.12) Table 37 shows the test results when 0.8 g (4.4%) of 29 denier (four strands) silk was added to 18.0 g of base material.

 Table 3 7

(Experiment No.13) Table 38 shows the test results when 0.1 g (0.55%) of 32 denier (6-twisted) silk was added to 18.0 g of base metal. . Table 3 8

(Experiment No.14) Table 39 shows the test results when 32 denier (six strands) of 0.4 g (2.2%) was added to 18.0 g of base metal. Show.

 Table 3 9

(Experiment No. 15) Table 40 shows the test results when 0 g (4.4%) of 32 denier (six strands) silk was added to 18.0 g of base material.

 Table 40

(Experiment No. 16) Table 41 shows the test results when 2.7 g (15%) of 32 denier (six strands) silk was added to 18.0 g of base material. Table 4 1 Maximum value (MAX) Break value (BREAK) Maximum limit value / (LOAD N) 107.824 103.097

 Bending value / plate (ELONG MM) 12.631 12.730

 Bending stress / MPa (STRESS MPa) 80.866 25.774

 Elongation value /% (STRAIN) 4.736 4.773 Experiment No.17) As a comparative example, Table 42 shows the test results of test pieces of polysulfone resin having specified dimensions.

 Table 4 2

 Maximum value (MAX) Break value (BREAK) Maximum limit value / N (LOAD N) 127.702 110.756

 Bending value / Marauder (ELONG MM) 10.800 10.817

 Bending stress / MPa (STRESS MPa) 95.782 83.067

 Elongation value (STRAIN) 4.0500 4.0564

(Experiment No. 18) As a comparative example, Table 43 shows the test results of a test piece of methyl methacrylate resin having specified dimensions.

 Table 4 3

Next, based on the above experimental results, tables and graphs for each silk shape mixed and added are shown.

44 to Table 48 and FIGS. 26 to 30. The data of the test results in Tables 44 to 48 and Figures 26 to 30 are the maximum limit value (unit: N), bending value (unit: mm), bending stress (unit: MPa), and elongation. The maximum value (MAX) is used as each value (unit:%) are doing. For comparison, the test results of the comparative test pieces of polysulfone resin and methyl methacrylate resin (without addition of silk) are also shown in the table and the graph.

 (i) The analysis results according to the amount of silk added to the composite plastic in the case where the added silk is powdery finely crushed pieces are shown in Table 44 and Figs. 26 (a) and (b).

 Table 44

 (ϋ) Table 45 and Fig. 27 (a) and Fig. 27 (b) show the analysis results according to the amount of silk added to the composite plastic when the added silk is 1.0 denier. Table 45

(iii) Table 46, Figure 28 (a) and Figure (b) show the analysis results according to the amount of silk added to the composite plastic when the added silk is two strands and 27 denier.

 Table 46

(iv) Table 47, Fig. 29 (a) and Fig. 29 (b) show the analysis results according to the amount of silk added to the composite plastic when the added silk is 4-strand and 29 denier. Table 47

(V) The analysis results according to the amount of silk added to the composite plastic in the case where the added silk is 6 twists and 32 deniers are shown in Table 48 and Figs. 30 (a) and 30 (b).

 Table 48

 Tables 49 to 51 and FIGS. 31 to 33 show different tables and graphs based on the mixing weight ratio (addition amount) of the dispersed and added silk fibers based on the above experimental results. The data of the test results in Tables 49 to 51 and Figs. 31 to 33 are the maximum limit value (unit: N), bending value (unit: mm), bending stress (unit: MPa), elongation value ( The maximum value (MAX) is adopted as each value of (unit:%). For comparison, the test results for the polysulfone resin and the methyl methacrylate resin (without addition of silk), which are comparative test pieces, are also shown in the table and the graph. For convenience, the mixed weight ratio of cotton denier 1.0 denier silk 0.055%, 0.22% and 0.44% is 0.55%, 2.2% and 4.4, respectively. % And the mixture weight ratio of 6-burned 32 denier silk (15% added (2.7 g added)) was displayed in all tables and graphs.

 (i) Table 49, Fig. 31 (a) and Fig. 31 (b) show the analysis results according to the silk shape when the added amount of silk is 0.1g (mixing weight ratio is 0.55%). Note 1.

The amount of 0 denier flocculent yarn added was 0.0 Olg (mixing weight ratio: 0.055%). Table 49

 (ii) The analysis results according to the silk shape when the amount of silk added was 0.4 g (mixing weight ratio 2.2) are shown in Table 50, and Figs. 32 (a) and (b). The amount of 1.0 denier cotton-like yarn added was 0.04 g (0.22% by weight).

 Table 50

(iii) The analysis results according to the silk shape when the added amount of silk was 0.8 g (mixing weight ratio 4.4%) are shown in Table 51, Figure 33 (a) and Figure 33 (b). The amount of 1.0 denier cotton-like yarn was 0.08 g (0.44% by weight). Table 5

The following conclusions can be drawn from the above analysis results by silk fiber shape and silk fiber mixture weight ratio (addition amount).

 First, considering Tables 44 to 48 and Figures 26 to 30 by silk fiber shape, the tip of the bar graph of the silk-added methyl methacrylate resin for all silk fiber shapes is as follows. However, it is always located above the top of the bar graph of methyl methacrylate resin without silk. Therefore, it is clear that the addition of silk clearly contributes to the improvement of the strength of the base material, and that the fiber-reinforced plastic has high strength.

 In addition, methyl methacrylate resin and polysulfone resin without added silk are compared with methyl methacrylate resin added with silk fiber, the maximum limit value N at the maximum load, the bending value Zmm for bending stress ZMPa, Elongation value Z% is low. On the other hand, for fiber-reinforced plastics to which silk fibers have been added, the bending value / mm and the elongation value /% also increase in proportion to the increase in the maximum limit value ZN at the maximum load and the bending force MPa. From this fact, the addition of silk improves the stress-strain relationship, in other words, the mechanical properties of the base material, and increases the strength and stickiness as compared with the case where no silk is added.

Also, from the above graph, it may not be said that the strength increases in proportion to the increase in the amount of silk fiber added. Table 52 shows the strength ranking according to the amount of silk added, extracted from Tables 44 to 48, by silk fiber shape. Table 52: Strength ranking is bending stress Judgment is based on ZM Pa data.

 Table 5 2

In Table 52, the 4.4% silk fiber mixture weight ratio exhibited relatively high strength in each of the 27, 29, and 32 denier twisted silk shapes, but was not the first in the strength ranking. Similarly, the 15-% silk blended weight ratio of 15% with 32 denier twisted yarn exhibited high strength, but was not the first in the strength ranking. In addition, the cottony yarn has a silk mixing weight ratio of 0.22%, and the 29, 32 denier twisted yarn has a silk mixing weight ratio of 2.2% and has the highest strength ranking. Considering the results of Example 1 (when the base material is methyl methacrylate resin), etc., it can be determined that the strength of the fiber reinforced plastic depends on the shape of the silk fiber added to the base material. It is considered that the silk fibers to be mixed and added have an optimum shape from the viewpoint of strength and an optimum mixing weight ratio range according to the shape.

 Here, theoretical considerations will be made for the above experimental results.

Judging from the test results, when adding silk fibers to the base material such as methyl methacrylate resin to improve the strength of the base material, the strength simply depends on the mixing weight ratio of the silk fibers. It seems that the strength is improved by the volume ratio of the silk fiber to the base material, the ratio of the silk fiber to the base material particles, and the cross-sectional area ratio of the silk fiber itself at the molecular level. The silk has a high affinity for the polymer plastic material, which is the base material of sericin surrounding the surface of the fiber bundle. It is conceivable that the produced silk exerts a crosslinking effect to improve the strength of the base material, or that the reinforcing effect of the bundle of the silk fiber structure itself increases the strength of the base material. Therefore, it is considered that the shape of the polymer, such as methyl methacrylate resin, in a chain form and the like is important for the silk fiber to be added, and the cross-linking action and the reinforcing action work synergistically. It is thought that this will result in a fiber-reinforced plastic with dramatically increased strength.

 Further, from the viewpoint of improving the strength as described above, it is considered that there is a more desirable shape of the added silk fiber and a mixed weight ratio thereof. For example, judging in Examples 1 to 4 above, the shape and thickness of the added silk fiber are desirably 2 twisted 27 denier twisted yarn, 4 burned 29 denier twisted yarn, 6 twisted 32 denier twisted yarn, and the like. The mixing weight ratio is preferably about 2.2% to 15%. This is because the silk fiber-in fiber itself has a structure that is easily compatible with high molecules and has an appropriate strength, and the fiber bronze fiber bundle has a thin and irregular cross section that is twisted and easily intersects with the base material molecules. In addition to improving the strength of the base material, it is also possible to improve the strength of the base material by making it easier to take in the base material molecules into the gap from which sericin has been removed by precision. For the above-mentioned reasons, by adjusting the fineness of the silk fiber, when high strength is required, the strength is improved by using the silk fiber which has been subjected to high fineness, and the pharmacological effect of sericin or the like such as a denture base is improved. If expected, it is possible to exert a pharmacological effect by using relatively low-accuracy silk fibers, and the fiber-reinforced plastic of the present invention has a variety of uses.

Next, the eligibility of the fiber reinforced plastic as a denture base will be described. Table 53 shows the characteristics of methyl methacrylate resin and polysulfone, which are typical materials that can be used for denture bases. Table 5 3

Methyl methacrylate resin and polysulfone resin have the above-mentioned advantages and disadvantages, but neither is an ideal denture base material. Therefore, a denture base is manufactured using fiber-reinforced plastics, which is a mixture of non-toxic methyl methacrylate resin and silk fibers. The method of manufacturing the denture base is substantially the same as the method of manufacturing a denture base using a normal denture base material such as methyl methacrylate resin, except that the denture base is manufactured using fiber-reinforced plastic.

As described above, the characteristics of denture bases manufactured using this fiber-reinforced plastic as a material are examined as follows: 1) Denture bases made of the fiber-reinforced plastics are higher in strength than denture bases of methyl methacrylate resin. 2) Denture base materials ③ It is safe for the human body because there is no danger of generating environmental hormones and dioxins. ④ Water retention by the added silk fiber ゃ Active drug such as sericin Sericin is expected to have an effect on the human body, etc. Sericin also has the ability to control cholesterol levels in blood in a benign manner. が あ る It has a positive effect on the environment from the production of fiber reinforced plastics. ⑥Silk fiber reinforced plastics And its denture base are easy to manufacture and low cost, and can easily be tailored to individual needs , There is a characteristic of equal, the favorable impact of the absence of high strength and the human body to normal denture And so on.

 When using other fiber reinforced plastics such as glass fiber reinforced plastic or carbon fiber reinforced plastic for products that are used directly on the human body such as denture bases, unlike silk fiber reinforced plastic, there are the following problems. For example, assuming that a denture base made of reinforced plastics mixed with glass fiber is used as a denture base, the denture base is attached to the human body, which is extremely dangerous and harmful to the human body and cannot meet safety standards. That is, when the wear rate of plastic and glass fiber is compared, the wear rate of plastic is larger, so that the exposed fiber may enter the oral cavity. Also, assuming that carbon fiber reinforced plastic is used as the denture base, dentures and denture bases are made to order of individuals, but it is necessary to deal with the order made with carbon fiber reinforced plastic denture bases. Is difficult to operate, and if a denture base is actually made of carbon fiber reinforced plastic as described above, enormous costs for machinery and equipment are required. On the other hand, the silk fiber reinforced plastic according to the present invention and its denture base have no such disadvantages. For example, even if the silk fiber is exposed from the denture base, the silk fiber is positively applied to the human body. It has a positive effect and has easy operability.

 Since the fiber-reinforced plastic and the denture base thereof according to the present invention have the above-mentioned constitution, they exhibit good properties such as high strength, and have high adaptability to ecological environment such as human body and nature, thereby preserving the global environment and protecting human body. This has the effect of maintaining the health of children. That is, the fiber-reinforced plastic and its denture base have no risk of producing chemical substances harmful to the ecological environment, such as dioxins and environmental hormones (endocrine disrupting chemicals) generated during waste incineration, and have properties such as strength. High performance can be achieved with

 In addition, since the above-mentioned fiber-reinforced plastic and its denture base are molded from synthetic resin, it is easy to process, has high operability and convenience, and has a low manufacturing cost and is economical. effective.

Furthermore, the above fiber-reinforced plastic and its denture base not only have no adverse effects on the ecological environment, but also have the effect of positively affecting the human body. That is, sericin, which forms the silk fiber structure, is a pharmacologically effective drug for mucosal and skin diseases. For example, denture bases used directly on the human body can maintain and improve the health of denture base users, including patients with the above-mentioned diseases, and reduce medical expenses · Reduction can be realized.

The above-mentioned fiber-reinforced plastic can be widely used for industrial products and the like in consideration of ecological environment. By producing and disseminating the fiber-reinforced plastic, an industry that can be said to be an environmental industry can be started. That is, since silk fibers required for the fiber-reinforced plastic are produced, cocoons and sericulture are indispensable, and a wide range of mulberry fields is required. As a result, fallow rice fields are used to promote agriculture and increase employment in rural areas. Further green is increased by planting mulberry, it reduces the C_〇 ₂ in the atmosphere, contributing to the improvement of the soil as a deciduous, effect of improved water quality near water can be expected.

Claims

The scope of the claims

1. A fiber-reinforced plastic characterized by adding a predetermined proportion of silk fibers dispersed in a synthetic resin that is harmless to the ecological environment.

 2. The fiber-reinforced plastic according to claim 1, wherein the synthetic resin is any one of methyl methacrylate resin, polyethylene, and polypropylene.

3. The fiber-reinforced plastic according to claim 1 or 2, wherein the silk fiber is any one of a powdery fine piece, a raw yarn shape, and a twisted yarn shape, or a combination thereof.

 4. A denture base characterized by being formed of fiber-reinforced plastic in which a predetermined proportion of silk is dispersed and added to a synthetic resin that is harmless to the ecological environment.