JP7138980B1 - RESIN COMPOSITION, ADHESIVE, RESIN MOLDED PRODUCT AND METHOD FOR MANUFACTURING RESIN MOLDED PRODUCT - Google Patents

Abstract

An object of the present invention is to provide a resin composition using natural or plant-derived raw materials that can be easily treated as waste. A resin containing (A) natural rubber, (B) a plant-derived thickener, and (C) a plant (excluding (A) the natural rubber and (B) the plant-derived thickener) composition. Furthermore, the plant is preferably at least one of fruit peels, particularly banana peels, apple peels, and grape peels, and further contains (D) a pH adjuster. [Selection figure] None

Description

Application of Article 30, Paragraph 2 of the Patent Law Announcement by broadcasting on March 18, 2021 TBS Television Co., Ltd.'s broadcast program "Asa Chan!"

The present invention relates to a resin composition, an adhesive, a resin molded article, and a method for producing a resin molded article.

At present, many resin compositions using synthetic resins are used. Resin compositions using synthetic resins have high versatility and are widely used not only for molded products but also for various purposes.

However, synthetic resin is an artificially synthesized resin material, and is difficult to decompose in a natural environment. For this reason, there is a problem regarding disposal of synthetic resins when they become wastes after use.

Accordingly, an object of the present invention is to provide a resin composition using natural or plant-derived raw materials that can be easily disposed of as waste.

In order to solve the above problems, claim 1 provides a resin composition containing (A) natural rubber, (B) a plant-derived thickener, and (C) a plant (excluding (A) and (B) above). Characterize things.
Claim 2 is characterized in that the (C) is a pericarp of a fruit.

According to claim 3, the fruit skin is at least one of banana skin, apple skin, and grape skin, and (D) a pH adjuster is included.
Claim 4 is characterized by an adhesive containing the resin composition according to any one of claims 1 to 3.

A fifth aspect of the present invention is characterized by a resin molded product obtained by forming the resin composition according to any one of the first to third aspects into a sheet.
In claim 6, raw materials including natural rubber, a plant-derived thickener, a plant (excluding the natural rubber and the plant-derived thickener), and water are mixed and heated to form a resin composition. and a step of molding the resin composition into a sheet.

Since the resin composition of the present invention uses natural or plant-derived raw materials, it can reduce the burden on the environment when it is disposed of as waste after use, compared to synthetic resins.

Hereinafter, one embodiment of the resin composition embodying the present invention will be described.
Regarding the Resin Composition The resin composition is not limited to any shape as long as it contains certain raw materials. Examples include solids, liquids, viscous bodies, and the like.

(A) Natural rubber is a concept that does not include artificially synthesized synthetic rubber. Natural rubber is a polymeric material made from sap (latex liquid) that can be collected when the bark of rubber trees is damaged.

The (B) plant-derived thickener is used to increase the viscosity of the resin composition to improve shape retention. Polysaccharides are preferred as plant-derived thickeners, and examples thereof include carrageenan, guar gum, xanthan gum, agar, corn starch, and potato starch.

The plant of (C) is a concept that taxonomically belongs to the plant kingdom of eukaryotes and does not include the kingdom of prokaryotes, the kingdom of fungi, and the kingdom of animals. In addition, the term "plant" is a concept that includes not only the entire structure of a plant but also part of a plant, such as roots, stems, trunks, bark, leaves, flowers, pericarp, fruits, and the like. As for the plant to be used, parts that are generally not used and discarded are preferable from the viewpoint of utilization of waste. In particular, from this point of view, among vegetables and fruits, vegetable skins and fruit skins that are not used for food and discarded are preferable. It is also preferable to discard coffee beans and tea leaves (black tea, roasted tea, green tea leaves) after extraction.

The pH adjuster (D) prevents the resin composition from becoming acidic (pH less than 7) when the plant (C) is used to prepare the resin composition. That is, when a resin composition containing natural rubber becomes acidic, the natural rubber alone may solidify without being mixed with other raw materials. Therefore, it is added to adjust the resin composition to a neutral to alkaline range (pH 7 to 10). Therefore, even if plants are used, they do not need to be used if the resin composition does not become acidic. A pH adjuster can be used, for example, baking powder, baking soda or sodium sesquiate. For the purpose of adjusting the pH of the resin composition, the type and amount of the pH adjuster to be added may be appropriately determined based on the pH of the resin composition before adjustment.

A dispersant may also be added to improve the dispersibility of each raw material constituting the resin composition. Dispersants include, for example, lignin. Furthermore, water may be used as a solvent for diluting or dissolving the resin composition or raw materials of the resin composition in the process of producing the resin composition.

About the mixing ratio of each raw material For each raw material, the natural rubber (A) is 100 parts by mass, the thickener (B) is 5 to 50 parts by mass, and the plant (C) is in the range of 10 to 70 parts by mass. It is preferred to use In addition, since the plant of (C) has a difference in water content in a so-called fresh state, the mass part is calculated by the weight in a dry state (dry weight). The dry weight is the weight when the plant is placed in a dryer at 80 to 90 degrees Celsius for 10 to 12 hours to remove moisture and returned to room temperature, and the weight does not change even if the drying time is prolonged. Say. That is, the dry weight is the weight of the fresh product with the water removed.

Next, a method for producing a resin composition will be described.
Mix natural rubber, thickener and plant, heat and homogenize. If it is difficult to mix the natural rubber, the thickener, and the plant raw materials alone, adding about 50 to 1,000 parts by weight of water to 100 parts by weight of the natural rubber facilitates mixing. Moreover, it is preferable to use the plant after pulverizing it. At this time, if the plant remains fresh, it can be used as a paste by a grinder. If the plant is in a dry state, it can be used in the form of granules or powder with a grinder. Although the plants can be used in either a fresh, dried or semi-dry state in between, the dry weight of the plants used is calculated as described above. Also, when the pH of the resin composition is acidic (less than pH 7), a pH adjuster is added to make the composition neutral or alkaline (pH 7-10). Furthermore, a dispersant may be used to improve the dispersibility of each raw material as needed.

Mixing of raw materials is facilitated under heated conditions. Moreover, some thickeners exhibit a thickening effect when heated to a certain temperature, so when such a thickener is used, it is heated to a predetermined temperature. For example, when agar is used as a thickening agent, it is heated to about 85 to 90 degrees. A resin composition is completed when each raw material is evenly mixed.

Applications of Resin Composition Next, applications of the resin composition will be described. The resin composition can be used for various purposes, and for example, the resin composition can be used as an adhesive. Also, the resin composition can be poured into a mold or the like to form a molded product. A molded product is not limited to a specific shape as long as it is molded into a certain shape. For example, sheet-like, cube-like, spherical, cylindrical, cone-like, polyhedron, and other shapes with some character motifs are included. It also includes those that have a certain shape but deform when external energy such as force or heat is applied.

Specific examples are shown below.
Production of Resin Composition A resin composition of Example 1 was produced using the following raw materials.

・ 50 grams of natural rubber (latex L-5000 manufactured by Kuo Yu Kasei Co., Ltd.)
・ 5 grams of thickener (agar powder for commercial use manufactured by Matsuki Agar Sangyo Co., Ltd.)
15 grams of banana peel (dry weight)
・10 grams of baking powder (Aikoku Co., Ltd.)
・ 5 grams of lignin (Sun Extract manufactured by Nippon Paper Industries Co., Ltd.)
- 100 grams of water Incidentally, the banana peel is the part of the banana fruit from which the pulp has been removed, and is the so-called banana peel. Banana peels were dried naturally and pulverized in a mill before use. The above raw materials were placed in a container, heated to 90° C. and kneaded. When the banana skin was used, the resin composition became acidic (about pH 6), so baking powder was used to make the resin composition alkaline (pH 8). A resin composition was produced according to the above procedure. The resin composition using the banana peel exhibited a brown color as a whole due to the browning of the banana peel during the drying process.

Further, under the same conditions as in Example 1, a resin composition was produced as Example 2 using 15 g (dry weight) of apple peel instead of banana peel. The apple peel is a portion of the apple peel cut off with a kitchen knife in the manner of peeling off the skin of the apple fruit. Since the apple peel is thin and integrated with the pulp, the peel is attached to the peel, and the dry weight of the peel is the weight including the pulp that has been removed. Apple peels were also dried naturally, and then pulverized into powder using a mill. The raw materials and amounts used are the same as in Example 1, except for the apple peel. The resin composition using the apple peel exhibited a reddish brown color as a whole because the apple peel is red.

Furthermore, under the same conditions as in Example 1, a resin composition was produced as Example 3 using 15 g (dry weight) of grape (muscat) peel instead of banana peel. The grape skin is what remains after the grape fruit is picked with the fingers and the pulp is removed. Grape skins were also dried naturally, and then pulverized into powder by a mill before use. The raw materials and amounts used are the same as in Example 1, except for the grape skins. The resin composition using grape skins exhibited a bluish brown color as a whole because the grape skins are yellowish green.

Furthermore, under the same conditions as in Example 1, a resin composition was produced as Example 4 using 15 grams (dry weight) of coffee beans instead of the banana peel. The coffee beans were ground to 0.4 to 0.6 mm and used for coffee extraction. Coffee beans were also used in a dry state by natural drying. Raw materials other than coffee beans and the amounts used are the same as in Example 1. The resin composition using coffee beans had a dark brown color as a whole because the coffee beans were dark brown.

Test for Adhesive Application The resin composition of Example 1 was applied to one entire side of a 10 cm wide, 10 cm long and 2 cm thick plywood board. The coating amount of the resin composition was 5 g/one side. The resin composition contains water added at the time of production, but since water evaporates as needed, the coating amount of the resin composition is the weight of the resin composition that does not contain water (other than water). In addition, the resin composition must be in a fluid state in order to use it as an adhesive. When the resin composition has solidified due to natural cooling or the like, it is reheated to a fluid state before it is used as an adhesive. The same type of plywood was laminated on the surface of the plywood to which the resin composition was applied, and the two plywood were clamped and left at room temperature for 24 hours. After the same time elapsed, the two plywood sheets laminated with the resin composition sandwiched therebetween were united and could not be easily peeled off, and the resin composition exerted its function as an adhesive. Similar results were obtained for Examples 2 and 3 as well.

Test for molding adhesive application Subsequently, 20 g of the resin composition of Example 1 was used for 10 g of wood chips obtained by pulverizing wood chips generated as construction waste to a size of about 0.5 to 1 mm. Mixed. The used weight of this resin composition is also the weight without water. Also, as described above, the resin composition is used in a fluid state. After that, the mixture of the wood chips and the resin composition was formed into a bottomed cylinder having a diameter of 8 cm, a height of 2 cm, and a thickness of 0.5 cm, and was air-dried for 3 days. The molded article after drying had an appearance like a cork product, and had strength to the extent that it would not easily collapse even when held by hand. Therefore, the resin composition exhibited a function as an adhesive for molding wood chips, and the resin composition itself exhibited a function as a molded article together with the chips. Similar results were obtained for Examples 2 and 3 as well.

Test for Use of Resin Molded Article The resin composition of Example 1 was put in a fluid state into a rectangular mold with a bottom having a width of 15 cm, a length of 20 cm and a thickness of 5 mm to produce a sheet-shaped resin molded article. The obtained sheet-like molded product had an irregular fine uneven pattern on its surface, and had a non-sticky, smooth texture similar to that of animal skins (leather). In addition, the color that appeared was also brown, and the atmosphere of leather appeared. Furthermore, the sheet-like material had self-adhesive properties, and even when one sheet-like material was pulled sideways in a state where two sheet-like materials were stacked, the stacked sheet-like materials did not peel off. In Examples 2 and 3, although the colors were different, similar results were obtained in appearance and texture. Also, for Example 4, a sheet-like resin molded product was similarly produced. In Example 4, since coffee beans were used, a fine pattern that was thought to be due to pulverized coffee beans appeared together with an irregular and fine rugged pattern. Other appearances and textures are the same as those of the first embodiment.

According to the resin composition of the above embodiment, the following effects can be obtained.
(1) In the above embodiment, a resin composition was produced using natural rubber, agar, and plants (banana skin, apple skin, grape skin, and coffee beans) as raw materials. Since the raw materials of resin compositions are plants or derived from plants, they are easily decomposed in the natural environment (easily returned to the soil), and when discarded as waste, the burden on the environment is reduced compared to synthetic resins.

(2) As plants, banana peels, apple peels, and grape peels are used. These pericarps are the parts that are not used for food when the fruit is used and are discarded without being used for other purposes. Therefore, the use of the pericarp of these plants as a raw material for the resin composition leads to the effective utilization of parts that would otherwise be discarded and the reduction of waste.

(3) Coffee beans are used as plants. Coffee beans are discarded after coffee is extracted. For this reason, the use of coffee beans as a raw material for the resin composition also leads to effective utilization of portions that would normally be discarded and reduction of waste.

(4) Resin moldings can be used as adhesives (adhesives for molding) and have versatility in applications.
(5) A resin molded article obtained by molding the resin composition into a sheet has a leather-like texture in terms of appearance and touch.

(6) Resin moldings have self-adhesiveness, and when sheet-shaped resin moldings are piled up, they adhere to each other. Therefore, the sheets can be adhered and fixed without using other fixing means.

Note that the above embodiment may be modified as follows.
- As the plant (C), not only a single portion (tissue) but also multiple (tissues) may be used.

If plant stems, leaf streaks, bast, cotton, etc. are used as the plant (C), a resin composition having improved strength due to plant fibers can be obtained.

Claims (5)

(A) natural rubber,
(B) a plant-derived thickener;
(C) fruit peel ( excluding (B) above ),
A resin composition containing 2. The resin composition according to claim 1 , wherein the fruit skin is at least one of banana skin, apple skin, and grape skin, and (D) a pH adjuster. An adhesive containing the resin composition according to claim 1 or 2 . A resin molded product obtained by forming the resin composition according to claim 1 or 2 into a sheet. a step of mixing and heating raw materials including natural rubber, a plant-derived thickener, fruit peel (excluding the plant-derived thickener), and water to form a resin composition;
and a step of molding the resin composition into a sheet.