Resin compositions and vehicle components

Abstract

To provide a new resin composition in which whitening caused by scratching of a molding is suppressed, and a vehicle member using the resin composition.SOLUTION: A resin composition contains in a colored resin, egg-shell powder, preferably, colored to a similar color to the resin.SELECTED DRAWING: Figure 3

Description

Technical Field

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[0001] The present disclosure relates to a resin composition and a vehicle member using this resin composition.

Background Art

[0002] Conventionally, a resin composition in which a filler is blended with a resin has been known (for example, see Patent Document 1). The filler is used, for example, to improve the rigidity of the resin used as a vehicle member. As such a filler, generally, talc, calcium carbonate, or the like is used.

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A resin composition used as a vehicle member such as a glove box preferably suppresses whitening caused by damage or the like. However, fillers such as talc and calcium carbonate blended for improving rigidity have a relatively large blending amount and are white in color, so that when they appear on the surface due to damage to the molded product, they can be a cause of whitening. Patent Document 1 discloses a resin composition that does not contain talc in order to suppress whitening.

[0005] An object of the present disclosure is to provide a novel resin composition capable of suppressing whitening due to damage to a molded product and a vehicle member using this resin composition.

Means for Solving the Problems

[0006] The present inventor focused on eggshells, which are industrial waste, and found that eggshell powder obtained by pulverizing eggshells rich in pores has minute irregularities remaining on the surface due to the pores even after pulverization, and when colored with a colorant such as a pigment or a dye, the colorant has good fixing, and the obtained colored eggshell powder is optimal as a filler for a resin capable of suppressing whitening of the resin.

[0007] A resin composition according to one aspect of this disclosure is a resin composition comprising colored eggshell powder in a main resin. Another aspect of this disclosure is a vehicle component made of this resin composition. [Effects of the Invention]

[0008] This resin composition can suppress whitening caused by scratches on molded products. Furthermore, vehicle components manufactured by molding from such a resin composition have a superior appearance with less visible scratches. In addition, the eggshells used as a filler are industrial waste materials available domestically, unlike talc which relies on imports, making it economically advantageous and contributing to a reduction in environmental impact. [Brief explanation of the drawing]

[0009] [Figure 1] Magnified image of an eggshell taken with an electron microscope. [Figure 2] Magnified electron microscope image of eggshell powder colored with pigments. [Figure 3] Magnified electron microscope image of eggshell powder colored with dye. [Figure 4] A table showing the formulations and physical properties of the examples and comparative examples. [Figure 5] A photograph showing the results of the test according to the example. [Figure 6] A photograph showing the results of a comparative example test. [Modes for carrying out the invention]

[0010] The resin composition in this disclosure is a main resin (hereinafter referred to as the main resin in this specification). The material contains ) and colored eggshell powder. The main resin is preferably a thermoplastic resin such as polypropylene resin or ABS resin (acrylonitrile-butadiene-styrene copolymer). A portion of the polypropylene resin may contain acid-modified polypropylene resin. The main resin is colored using a coloring agent by a method well known to those skilled in the art.

[0011] The colored eggshell powder used as a filler in resin compositions is obtained by crushing eggshells to produce eggshell powder, which is then colored with a dye or pigment. Eggshell powder is obtained by crushing bird eggs, preferably white chicken eggs. Specifically, it is produced by washing chicken eggs or other eggshells with water, coarsely crushing them, removing the eggshell membrane, then dehydrating and drying them, and finally finely crushing them. Eggshells do not contain water and are mainly composed of calcium carbonate, with trace amounts of magnesium carbonate and calcium phosphate.

[0012] The eggshell powder content is preferably 3 to 40% by weight of the resin composition, more preferably 5 to 30% by weight, and particularly preferably 10 to 25% by weight.

[0013] Figure 1 is a magnified photograph of an eggshell taken with an electron microscope at 5000x magnification. The eggshell membrane (a long, slender rod-shaped structure) is visible as the uppermost layer, but as will be discussed later, the eggshell membrane is removed when eggshell powder is used as a filler. The thickness of an eggshell is generally 300 to 500 μm. The cross-section of an eggshell contains countless pores (approximately 10,000 to 30,000 per chicken eggshell) for gas exchange, such as releasing carbon dioxide and taking in oxygen (see arrows in Figure 1).

[0014] When using eggshell powder as a filler to improve impact resistance and reinforce strength, the particle size of the eggshell powder is preferably about 1 to 50 μm. More preferably, it is 1 to 40 μm. Eggshells are made up of countless crystalline layers, which are deposited radially starting from each papillary nucleus. This structure creates the pores of the eggshell. Therefore, even when eggshells are powdered to the above particle size, pores remain on the particle surface, and countless irregularities exist. Since the coloring agent penetrates into these irregularities, the coloring agent adheres easily to the eggshell.

[0015] In contrast, seashells (e.g., oyster shells), which also have calcium carbonate as their main component, have an uneven surface before grinding, but when ground to, for example, about 10 μm, the surface of the powder becomes almost completely smooth. This is because, during the growth process of the seashell, calcium carbonate is deposited in a linear layer along the longitudinal direction. Therefore, achieving good coloration of seashell powder becomes quite difficult.

[0016] The colorant for coloring the eggshell powder may be a colorant having the same color or an approximate color as the colorant contained in the main material resin. For example, when the colorant contained in the main material resin is black, the colorant added to the eggshell powder may be black or a color approximate to black. As the colorant, either a dye having a particle diameter generally of 1 nm to 3 nm or a pigment having a particle diameter of 50 nm to 1000 nm (= 1 μm) can be used.

[0017] Coloring of the eggshell powder can be carried out by the following method.

[0018] First, prepare the eggshell powder and add a colorant for coloring the eggshell to the eggshell powder. The amount of the colorant is preferably about 1 / 20 of the mass weight of the eggshell powder, but may be varied within the range of 1 / 10 to 1 / 30.

[0019] When the colorant is a dye, since its particle size is 1 to 3 nm (= 0.001 to 0.003 μm), which is extremely small compared to the particle diameter of the eggshell powder (preferably 1 to 50 μm), due to the anchor effect (described later) caused by the surface irregularities and pores of the eggshell powder, the dye alone can sufficiently adhere and fix to the eggshell powder.

[0020] On the other hand, in the case of a pigment having a maximum particle diameter of 1 μm, the difference in particle diameter between the pigment and the eggshell powder is small, and it is difficult to expect the fixation of the pigment due to the anchor effect of the eggshell powder. Therefore, a method of using a binder in combination with the pigment to fix it to the eggshell powder can be adopted. As the binder, for example, a water-soluble acrylic resin, a urethane resin, etc. can be used. The amount of the binder can be varied according to the particle diameter of the eggshell powder, but it is better to be less within the range required for pigment fixation, and the amount can be determined by experiments. Even when using a binder, the total amount of the pigment and the binder may be the amount of the above-mentioned colorant.

[0021] Next, while stirring to prevent the eggshell powder from aggregating, an acid is added and the temperature is raised from 90°C to 95°C for stabilization. As the acid to be added, inorganic acids such as hydrochloric acid and organic acids such as formic acid can be used. However, formic acid is particularly preferred because of its low production cost. In the case of formic acid, an aqueous solution with a concentration of 1 to 5% by weight is appropriate.

[0022] Next, the colored eggshell powder is cooled to about 10°C, and then, if necessary, a polymer agent is added for stabilization. As the polymer agent, anionic polymers and the like can be used.

[0023] Next, the colored eggshell powder is washed with water to remove the attached acid and excess polymer agent. Then, it is heated by a heater to be dried, and at the same time, the colorant is baked and fixed.

[0024] Note that the eggshell membrane needs to be removed from the eggshell powder because it causes a putrid odor. According to this coloring method, in the step of adding an acid, the eggshell membrane is dissolved by the acid, and in the step of removing the attached acid by washing with water, the dissolved eggshell membrane is removed together with the acid. That is, according to this coloring method, the eggshell membrane can be removed simultaneously with coloring.

[0025] Figure 2 is an enlarged photograph of eggshell powder colored with a pigment as a colorant, magnified 2500 times by an electron microscope. Figure 3 is an enlarged photograph of eggshell powder colored with a dye as a colorant, magnified 2500 times by an electron microscope. In the case of using either a pigment or a dye as the colorant, it can be observed that the colorant is fixed to the eggshell powder. This is considered to be due to the capillary effect of the binder or colorant entering the unevenness formed by the pores on the surface of the eggshell powder, in addition to the affinity between the calcium carbonate contained in the eggshell powder and the colorant.

[0026] When eggshell powder is colored using a binder, the binder enters the pores on the eggshell surface, causing the coloring agent to clump around the pores. However, when eggshell powder is colored using a dye, the coloring agent enters the pores on the eggshell surface, resulting in uniform coloring of the eggshell surface. Therefore, when coloring eggshell powder, coloring with a dye is preferable.

[0027] Furthermore, the coloring method is not limited to the methods described above; eggshell powder can also be colored using methods similar to those used for coloring polyester and other materials.

[0028] The resin composition may contain, in addition to the main resin and eggshell powder used as a filler, other additives commonly used in resin compositions, if desired. Examples of such additives include antioxidants, antistatic agents, ultraviolet absorbers, and colorants (if the main resin is not colored).

[0029] The resin composition is pelletized using an extrusion molding machine or the like. The resulting pellets are then used to manufacture resin molded articles using well-known plastic molding methods, such as extrusion molding, injection molding, blow molding, and hot pressing. The resin molded articles can be used as interior components for vehicles, such as glove boxes. [Examples]

[0030] Using the following raw material components, resin composition pellets were produced using an extrusion molding machine according to the formulations shown in the table in Figure 4, and plate-shaped resin molded bodies were created by injection molding.

[0031] Polypropylene: Product name; Novatec PP BC05GS, manufactured by Nippon Polypropylene Co., Ltd. (black colored) Talc: Product name; SK-7800, manufactured by Kaijo Co., Ltd. (average particle size: 25 μm) Colored eggshell powder: Eggshell powder obtained by crushing eggshells to an average particle size of 25 μm is colored using a black dye (product name: LANASET® Dyes Heinzmann Japan) as a coloring agent, in the method using formic acid as described above.

[0032] A scratch resistance test (scratch test) was performed on the polypropylene resin molded articles of the examples and comparative examples.

[0033] The scratch resistance test was conducted using an Eriksen scratch hardness tester (tip diameter 0.75 mm), applying a load of 10 N and a speed of 50 mm / s to scratch a 50 mm straight line, and visually inspecting the degree of scratching and the presence or absence of whitening.

[0034] As can be seen by comparing the photographs in Figure 5 and Figure 6, although the whitening phenomenon occurs in the resin composition according to the example shown in Figure 5, the area of ​​whitening is clearly smaller compared to the resin composition according to the comparative example shown in Figure 6.

[0035] Thus, by coloring the eggshell powder with the same or a similar color as the main resin of the resin composition, it will blend in with the main resin even when scratched or exposed, making the scratches less visible and helping to maintain a good appearance.

[0036] Furthermore, the hardness of the resin composition of this disclosure is improved by the calcium carbonate contained in the eggshell powder. As a result, the scratching material is less likely to penetrate the resin molded body. Consequently, scratches are shallower and the scratches are less visible.

[0037] Furthermore, talc poses concerns regarding transportation costs and safety, making its inclusion in resin compositions used as vehicle components undesirable.

[0038] Furthermore, the resin composition of this disclosure contains eggshell powder, which contributes to the recycling of eggshells, which are waste materials.

[0039] Furthermore, eggshell powder offers a better anchoring effect for colorants than talc, making it easier to color. This expands the range of choices for colorants based on their required material properties (light resistance, impact resistance, chemical resistance, etc.). As a result, it is easier to improve the appearance when used as a vehicle component.

[0040] Although embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention.

Claims

1. The process of preparing the main resin material, The process involves preparing colored eggshell powder that has been colored with a coloring agent, A step of blending the main resin material and the colored eggshell powder, A method for producing a resin composition comprising the above.

2. The main material is a resin, Colored eggshell powder colored with a coloring agent different from the coloring agent contained in the main resin material, A resin composition containing the following:

3. A vehicle component molded from the resin composition described in Claim 2.

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