阅读说明：本技术 树脂制品及其制造方法 (Resin product and method for producing same ) 是由 太田孝 佐野刚志 绀野良文 于 2019-10-29 设计创作，主要内容包括：本发明提供一种伤痕不显眼的高品质的树脂制品及其制造方法。树脂制品(1)具备：包含合成树脂的基材(10)、及设置在基材(10)的表面(10a)的涂膜(20)。涂膜(20)包含合成树脂(30)、及分散状态的中空无机粒子(40)。中空无机粒子(40)的中位径a为10～50μm。中空无机粒子(40)的真比重为0.55～1.20。涂膜(20)中,无中空无机粒子(40)的部分(31)的厚度为8μm以上且为0.3a～1.2a。中空无机粒子(40)的一部分在涂膜(20)的表面(20a)露出。(The invention provides a high-quality resin product with inconspicuous scars and a manufacturing method thereof. A resin product (1) is provided with: a base material (10) containing a synthetic resin, and a coating film (20) provided on the surface (10a) of the base material (10). The coating film (20) contains a synthetic resin (30) and hollow inorganic particles (40) in a dispersed state. The median diameter a of the hollow inorganic particles (40) is 10 to 50 μm. The hollow inorganic particles (40) have a true specific gravity of 0.55 to 1.20. In the coating film (20), the thickness of the portion (31) without the hollow inorganic particles (40) is 8 [ mu ] m or more and 0.3a to 1.2 a. A part of the hollow inorganic particles (40) is exposed on the surface (20a) of the coating film (20).)

1. A resin product comprising:

a substrate comprising a synthetic resin, and

a coating film provided on the surface of the base material,

the coating film comprises a synthetic resin and hollow inorganic particles in a dispersed state,

the median diameter a of the hollow inorganic particles is 10 to 50 μm,

the hollow inorganic particles have a true specific gravity of 0.55 to 1.20,

the thickness of the part of the coating film without the hollow inorganic particles is more than 8 mu m and 0.3 a-1.2 a,

a part of the hollow inorganic particles is exposed on the surface of the coating film.

2. The resin article according to claim 1, wherein the synthetic resin contained in the coating film has transparency.

3. A method for producing a resin product, which comprises providing a coating film comprising a synthetic resin and hollow inorganic particles dispersed therein on the surface of a base material,

the median diameter a of the hollow inorganic particles is 10 to 50 μm,

the hollow inorganic particles have a true specific gravity of 0.55 to 1.20,

the manufacturing method comprises the following steps:

a coating step of coating a coating liquid in which the hollow inorganic particles are dispersed in a resin material to be the synthetic resin on the surface of the base material so that the thickness of a portion of the coating film where the hollow inorganic particles are absent is 8 μm or more and 0.3a to 1.2a,

and a polishing step of polishing the surface of the coating film formed on the surface of the base material to expose a part of the hollow inorganic particles on the surface of the coating film.

Technical Field

The present invention relates to a resin article and a method for producing the same.

Background

Artificial marble is used in the countertops or sinks of integrated kitchens, countertops or basins of wash stands, bathtubs, etc. For example, a resin composition for artificial marble is injected into a mold and cured to form a molded article of artificial marble.

Patent document 1 discloses a coated artificial marble for use in a kitchen, which has a coating film formed on the surface of the artificial marble. The coating film contains one or both of a resin, an antioxidant and a light stabilizer so that the coating film can have an excellent appearance over a long period of time even when foreign matter including deteriorated oil or fat adheres thereto.

Disclosure of Invention

Problems to be solved by the invention

However, when the surface on which the artificial marble is coated is damaged, not only the coating film but also the artificial marble is sometimes damaged. In this case, the scratch on the artificial marble becomes conspicuous.

The above problems are also present in general kitchen-use coated artificial marbles such as coated articles such as washstands and bathtubs.

The invention discloses a high-quality resin product with inconspicuous scars and a manufacturing method thereof.

Means for solving the problems

The resin product of the present invention has the following modes:

it is provided with:

a substrate comprising a synthetic resin, and

a coating film provided on the surface of the substrate,

the coating film comprises a synthetic resin and hollow inorganic particles in a dispersed state,

the median diameter a of the hollow inorganic particles is 10 to 50 μm,

the hollow inorganic particles have a true specific gravity of 0.55 to 1.20,

the thickness of the part of the coating film where the hollow inorganic particles are absent is 8 μm or more and 0.3a to 1.2a,

a part of the hollow inorganic particles is exposed on the surface of the coating film

In addition, the present invention has the following modes:

a method for producing a resin product comprising a base and, provided on the surface thereof, a coating film comprising a synthetic resin and hollow inorganic particles dispersed therein,

the median diameter a of the hollow inorganic particles is 10 to 50 μm,

the hollow inorganic particles have a true specific gravity of 0.55 to 1.20,

the manufacturing method comprises the following steps:

a coating step of coating a coating liquid in which the hollow inorganic particles are dispersed in a resin material to be the synthetic resin on the surface of the base material so that the thickness of a portion of the coating film where the hollow inorganic particles are absent is 8 μm or more and 0.3a to 1.2a,

and a polishing step of polishing the surface of the coating film formed on the surface of the substrate to expose a part of the hollow inorganic particles on the surface of the coating film.

Effects of the invention

According to the present invention, a high-quality resin product with inconspicuous scratches and a method for producing the same can be provided.

Drawings

Fig. 1 is a sectional view schematically showing an example of a resin article.

Fig. 2 is a cross-sectional view schematically showing a main part of a resin article as an example in an enlarged manner.

Fig. 3 is a cross-sectional view schematically showing an example of a resin article having a colored layer.

Fig. 4 is a diagram schematically illustrating an example of a method of manufacturing a resin product.

Fig. 5 is a diagram schematically illustrating a scratch test method.

Description of the symbols

1 … resin product, 2 … semi-finished product,

10 … base material, 10a … front surface, 10b … back surface, 11 … base layer, 12 … coloring layer,

20 … coating film, 20a … surface, 25 … coating liquid, 25a … surface,

30 … synthetic resin, 31 … part without hollow inorganic particles, 32 … part, 35 … resin material,

40 … hollow inorganic particles, 41 … hollow part, 42 … exposed part,

S1 … base material forming step, S2 … coating step, S3 … polishing step.

Detailed Description

Embodiments of the present invention will be described below. Needless to say, the following embodiments are merely illustrative of the present invention, and all the features shown in the embodiments are not essential to the means for solving the problem of the present invention.

(1) Summary of the technology encompassed by the present invention:

first, an outline of the technique included in the present invention will be described with reference to examples shown in fig. 1 to 5. The drawings in the present application are schematically illustrating examples, and the magnification ratios in the respective directions shown in these drawings may be different, and the drawings may not be identical. Needless to say, each element of the present technology is not limited to the specific example shown by the reference numeral.

In the present application, the numerical range "Min to Max" means a minimum value Min or more and a maximum value Max or less.

[ means 1]

A resin product 1 according to an aspect of the present technology includes: a base material 10 containing a synthetic resin, and a coating film 20 provided on a surface 10a of the base material 10. The coating film 20 includes a synthetic resin 30 and hollow inorganic particles 40 in a dispersed state. The hollow inorganic particles 40 have a median diameter a of 10 to 50 μm. The hollow inorganic particles 40 have a true specific gravity of 0.55 to 1.20. In the coating film 20, the thickness of the portion 31 not having the hollow inorganic particles 40 is 8 μm or more and 0.3a to 1.2 a. A part of the hollow inorganic particles 40 is exposed on the surface 20a of the coating film 20.

In the above embodiment 1, since the thickness t of the portion 31 of the coating film 20 where the hollow inorganic particles 40 are absent is 8 μm or more, the coating film 20 is uniform, and the strength and design of the surface (20a) of the resin product 1 are good. The medium diameter a of the hollow inorganic particles 40 is 10 to 50 μm, and the surface (20a) of the resin product 1 has good design properties. Further, since the hollow inorganic particles 40 have a true specific gravity of 0.55 to 1.20, the hollow inorganic particles 40 are well dispersed in the synthetic resin 30, and the coating film 20 is uniform. Further, since the thickness t is 0.3a or more, the hollow inorganic particles 40 are held by the synthetic resin 30 and do not fall off from the coating film 20. This prevents deterioration in appearance such as pinholes due to the falling off of the hollow inorganic particles 40, and improves the abrasion resistance and scratch resistance of the surface (20a) of the resin product 1. On the other hand, since the thickness t is 1.2a or less, the hollow inorganic particles 40 are exposed from the surface 20a of the coating film 20 in a large amount, and the abrasion resistance and scratch resistance of the surface (20a) of the resin product 1 are improved. Here, even if the surface (20a) of the resin product 1 is damaged, the damage to the substrate 10 is suppressed by the hard hollow inorganic particles 40 in a dispersed state, and the synthetic resin 30 is not conspicuous even if the damage is applied in a state where a part of the hollow inorganic particles 40 is exposed on the surface 20a of the coating film 20. Therefore, the present embodiment can provide a high-quality resin product in which scratches are inconspicuous.

Here, the median diameter a is: by complying with ISO 13220: 2009 based JIS Z8825: 2013 (particle size analysis-laser diffraction/scattering method), namely, a particle size x of 50 vol% in cumulative distribution, i.e., a volume-based median diameter x₅₀。

The true specific gravity is set as: the density of the hollow inorganic particles themselves not including the voids between the hollow inorganic particles in a state where the hollow portions in the hollow inorganic particles remain. The true specific gravity is a dimensionless quantity substantially equal to the true density (unit: g/cm)³) The same is true.

The hollow inorganic particles are partially exposed as follows: a part of the hollow inorganic particles is not covered with the synthetic resin.

The above-described reference is also applicable to the following embodiments.

[ means 2]

The synthetic resin 30 contained in the coating film 20 may have transparency. In this embodiment, even if the synthetic resin 30 is damaged in a state where a part of the hollow inorganic particles 40 is exposed on the surface 20a of the coating film 20, the synthetic resin 30 has transparency, and thus the scratch is further inconspicuous. Therefore, the present embodiment can provide a high-quality resin product in which the scratch is more inconspicuous.

Here, the transparency of the synthetic resin in the coating film means that: the appearance of the surface of the base material can be slightly known through the synthetic resin in the coating film, and the synthetic resin is not limited to the transparency. Therefore, the synthetic resin in the coating film may be translucent or colored.

Note that the remarks of the above-described embodiment 2 are also applicable to the following embodiments.

[ means 3]

A method for producing a resin product 1 according to one embodiment of the present technology is a method for producing a resin product 1 including a coating step S2 and a polishing step S3, in which a coating film 20 in which hollow inorganic particles 40 are dispersed in a synthetic resin 30 is provided on a surface 10a of a base material 10. Here, the median diameter a of the hollow inorganic particles 40 is 10 to 50 μm, and the true specific gravity of the hollow inorganic particles 40 is 0.55 to 1.20. In the coating step S2, the coating liquid 25 in which the hollow inorganic particles 40 are dispersed in the resin material 35 that is the synthetic resin 30 is applied to the surface 10a of the base material 10 such that the thickness of the portion 31 of the coating film 20 in which the hollow inorganic particles 40 are absent is 8 μm or more and 0.3a to 1.2 a. In the polishing step S3, the surface 20a of the coating film 20 formed on the surface 10a of the substrate 10 is polished so that a part of the hollow inorganic particles 40 is exposed on the surface 20a of the coating film 20.

In embodiment 3, since the coating liquid 25 is applied so that the thickness t of the portion 31 of the coating film 20 where the hollow inorganic particles 40 are absent is 8 μm or more, a uniform coating film 20 is formed. This improves the strength and design of the surface (20a) of the resin product 1. The medium diameter a of the hollow inorganic particles 40 is 10 to 50 μm, and the surface (20a) of the obtained resin product 1 has good design properties. Further, since the true specific gravity of the hollow inorganic particles 40 is 0.55 to 1.20, the hollow inorganic particles 40 are stably dispersed in the coating liquid 25 without excessive floating or settling. This forms a uniform coating film 20 in which the hollow inorganic particles 40 are well dispersed in the synthetic resin 30. Further, since the thickness t is 0.3a or more, the hollow inorganic particles 40 are held by the synthetic resin 30 and do not fall off from the coating film 20. This prevents deterioration in appearance such as pinholes due to the falling of the hollow inorganic particles 40, and improves the abrasion resistance and scratch resistance of the surface (20a) of the resin product 1. On the other hand, since the thickness t is 1.2a or less, by polishing the surface 20a of the coating film 20, a large amount of the hollow inorganic particles 40 are exposed, and the abrasion resistance and scratch resistance of the surface (20a) of the resin product 1 are improved. Here, even if the surface (20a) of the resin product 1 is damaged, the damage to the substrate 10 is suppressed by the hard hollow inorganic particles 40 in a dispersed state, and the damage to the synthetic resin 30 is not noticeable even if the synthetic resin 30 is damaged in a state where a part of the hollow inorganic particles 40 is exposed on the surface 20a of the coating film 20. Therefore, the present embodiment can provide a method for producing a high-quality resin product with inconspicuous scratches.

The resin product 1 can be applied to a kitchen unit, a bathroom unit, a washstand, and the like. In the case of a kitchen unit, the resin product 1 can be applied to a kitchen counter, a kitchen sink, or the like. In the case of a whole bathroom, the resin product 1 can be applied to a bathtub, a bathroom counter, or the like. In the case of a washstand, the resin article 1 may be applied to a washstand, or the like.

(2) Specific examples of the resin product:

fig. 1 schematically illustrates a cross section of a resin product 1 according to an embodiment of the present technology. The resin product 1 includes: a base material 10 containing a cured or hardened synthetic resin, and a coating film 20 provided on a surface 10a of the base material 10. The base material 10 is preferably an artificial marble containing a filler, particularly an inorganic filler. The artificial marble is a resin material containing one of a filler and a synthetic resin as a main component and the other as a sub-component. Here, the main components mean: no other ingredients, or the most ingredients when other ingredients are present. The subcomponent means a component other than the main component. The coating film 20 includes a cured or hardened synthetic resin 30 and hollow inorganic particles 40 in a dispersed state. The synthetic resin 30 is preferably a transparent synthetic resin in order to make the damage less noticeable.

The synthetic resin contained in the substrate 10 and the synthetic resin 30 contained in the coating film 20 may be a curable resin such as a thermosetting resin, or may be a thermoplastic resin. As the thermosetting resin, an unsaturated polyester resin, a thermosetting acrylic resin, an epoxy resin, a vinyl ester resin, a phenol resin, a urea resin, a urethane resin, a silicone resin, a fluorine resin, a combination of at least some of these resins, or the like can be used. As the thermoplastic resin, a thermoplastic acrylic resin or the like can be used. As the transparent thermosetting resin for coating, a transparent thermosetting resin such as a urethane resin including an acrylic urethane resin, a polyester urethane resin, or the like, an unsaturated polyester resin, a thermosetting acrylic resin, an epoxy resin, a vinyl ester resin, a phenol resin, a urea resin, a silicone resin, a fluorine resin, or a combination of at least some of these resins can be used. As the transparent thermoplastic resin for coating, a transparent thermoplastic resin such as a thermoplastic acrylic resin can be used. The synthetic resin may contain one or more additives selected from ultraviolet absorbers, flame retardants, antioxidants, light stabilizers, and the like, within a range that does not impair the effects of the present technology.

Colored additives such as fillers and colorants may be included in the substrate 10. When the substrate 10 contains the colored additive, the substrate 10 may be formed into artificial marble or the like, and the surface of the resin product 1 may be given a texture such as a ceramic texture. Here, the ceramic style means: with the charm of pottery including pottery and the like. The filler may be an organic filler, and when an inorganic filler is used, the base material 10 is further hardened and hardly damaged, and the surface of the resin product 1 is less scratched. As the inorganic filler, one or more kinds of powder materials and granular materials selected from aluminum hydroxide, calcium carbonate, glass, silica, barium sulfate, magnesium carbonate, alumina, aluminum silicate, magnesium silicate, calcium sulfate, magnesium hydroxide, calcium hydroxide and the like can be used. As the colorant, at least one of an inorganic colorant and an organic colorant may be used, and a pigment or a dye may be used. As the inorganic colorant, there can be used: white pigments such as titanium oxide, zinc oxide, and zinc sulfide; yellow pigments such as iron oxide yellow; black pigments such as carbon black and iron oxide black; red pigments such as iron oxide red; blue pigments such as ultramarine blue; and the like. As the organic colorant, one or more of a blue pigment such as phthalocyanine blue, a yellow pigment such as isoindolinone yellow, an orange pigment such as diketopyrrolopyrrole, and the like can be used.

The pencil hardness of the base material 10 is preferably 4H or more, and more preferably 5H or more. Here, the pencil hardness is set as: based on JISK 5600-5-4: 1999 (general coating test method-part 5: mechanical properties of coating film-part 4: scratch hardness (pencil method)). When the base material has a pencil hardness of 4H or more, the base material is less likely to be scratched, and the scratch on the surface of the resin product 1 becomes particularly inconspicuous. In order to harden the base material, for example, a hard material may be used as the inorganic filler, or the amount of the inorganic filler contained in the base material may be increased.

The presence ratio of the inorganic filler in the base material 10 depends on the target hardness of the base material, but is not particularly limited, and may be, for example, about 1 to 90 wt%, and more preferably about 25 to 75 wt%.

In the coating film 20 containing the synthetic resin 30, there are many hollow inorganic particles 40 having hollow portions 41 among inorganic materials dispersed therein. Here, as shown in the upper part of fig. 1, for each hollow inorganic particle 40, the ratio of the ratio based on JIS Z8825: the particle diameter of 2013 is d. When the hollow inorganic particles 40 are normal spheres, the particle diameter d is the diameter of the hollow inorganic particles 40. The median diameter a of the hollow inorganic particles 40 is 50 vol% of the median diameter x determined from the volume-based cumulative distribution of the particle diameter d₅₀. InThe median diameter a of the hollow inorganic particles 40 is 10 to 50 μm. When the median diameter a is 9 μm or less, the unevenness on the surface of the coating film is small, and hence the photosensitivity is weakened. By setting the median diameter a to 10 μm or more, a moderate matte feeling is produced by the irregularities of the surface 20a of the coating film 20, and a moderate texture and touch such as a ceramic texture are produced. When the median diameter "a" is 51 μm or more, roughness of the surface of the coating film becomes conspicuous and the texture is reduced. By setting the median diameter a to 50 μm or less, the surface 20a of the coating film 20 is not excessively rough, and the surface of the resin product 1 has good design and touch.

The hollow inorganic particles 40 may be hollow particles of an inorganic material such as volcanic deposits such as glass and white sand (japanese: シラス). When a transparent material such as glass is used for the hollow inorganic particles 40, the appearance of the surface 10a of the substrate 10 can be known through the hollow inorganic particles 40, and hence the design of the surface of the resin product 1 can be improved.

The hollow inorganic particles 40 having the hollow portions 41 have a true specific gravity of 0.55 to 1.20, which is smaller than that of the inorganic material having no hollow portions. When the true specific gravity is 0.54 or less, even if an aggregate of the hollow inorganic particles 40 is mixed into a liquid resin composition for forming the synthetic resin 30, the aggregate excessively floats up, and the uneven coating film 20 of the hollow inorganic particles 40 is formed. When the true specific gravity of the hollow inorganic particles 40 is 0.55 or more, the hollow inorganic particles 40 are stably dispersed in the liquid resin composition to form the uniform coating film 20. When the true specific gravity of the hollow inorganic particles 40 is 1.21 or more, even if the aggregate of the hollow inorganic particles 40 is mixed into the liquid resin composition for forming the synthetic resin 30, the aggregate excessively sinks, and the uneven coating film 20 of the hollow inorganic particles 40 is formed. When the true specific gravity of the hollow inorganic particles 40 is 1.20 or less, the hollow inorganic particles 40 are stably dispersed in the liquid resin composition to form the uniform coating film 20.

In fig. 2, a main part of a cross section of the resin article is enlarged and schematically shown. As shown in fig. 1 and 2, the surface 20a of the coating film 20 has irregularities due to the presence of the hollow inorganic particles 40. Here, the thickness of the portion 31 of the coating film 20 where the hollow inorganic particles 40 are absent is represented by t. The thickness t is 8 μm or more and 0.3a to 1.2 a.

When the thickness t is 7 μm or less, the coating liquid 25 containing the hollow inorganic particles 40 in a dispersed state cannot be uniformly applied to the surface 10a of the substrate 10. When the thickness t is set to 8 μm or more, the coating liquid 25 can be uniformly applied to the surface 10a of the substrate 10 to form a uniform coating film 20. Thus, the resin product 1 having a surface with excellent strength and design properties is obtained.

When the thickness t is 0.2a or less, the hollow inorganic particles 40 may fall off from the coating film 20 to cause pinholes and the like in the coating film 20, and the design of the resin product 1 may be deteriorated. If the thickness t is 0.3a or more, the hollow inorganic particles 40 are held by the synthetic resin 30 and do not fall off from the coating film 20. This prevents a reduction in appearance such as pinholes and improves the abrasion resistance and scratch resistance of the surface of the resin product 1. On the other hand, when the thickness t is 1.3a or more, a large amount of the hollow inorganic particles 40 are embedded in the coating film 20, and the abrasion resistance and scratch resistance of the surface of the resin product 1 are reduced. When the thickness t is 1.2a or less, a large number of the hollow inorganic particles 40 are exposed by polishing the surface 20a of the coating film 20, and the abrasion resistance and scratch resistance of the surface of the resin product 1 are improved.

On the surface 20a of the coating film 20, a part of the hollow inorganic particles 40 is exposed by polishing. Fig. 1 and 2 show exposed portions 42 of the hollow inorganic particles 40. On the surface of the coating film 20 before polishing, the synthetic resin 30 covers the hollow inorganic particles 40 even at the convex portions where the hollow inorganic particles 40 exist. Polishing is performed to remove the synthetic resin 30 covering the hollow inorganic particles 40 at the convex portions of the surface of the coating film 20, leaving the convex outer shape of the hollow inorganic particles 40. By the polishing, a part of the outer shape of the hollow inorganic particles 40 appears, and the gloss of the hollow inorganic particles 40 in a dispersed state is imparted to the surface of the resin product 1. The matte effect due to the irregularities on the surface 20a of the coating film 20 and the glossy effect due to the convex outer shape of the hollow inorganic particles 40 polished cooperate with each other to obtain a resin product 1 having good design properties such as a ceramic texture and high surface hardness.

The presence ratio of the hollow inorganic particles 40 in the coating film 20 depends on the particle diameter of the hollow inorganic particles 40 and the thickness t, and may be, for example, about 0.5 to 20 wt%, and more preferably about 1 to 10 wt%.

The coating film 20 may be formed not only on the front surface 10a of the substrate 10 but also on the back surface 10b of the substrate 10.

As shown in fig. 3, the base material 10 including the synthetic resin may have a plurality of layers. The substrate 10 shown in fig. 3 has a colored layer 12 on a surface 10a provided with a coating film 20, and the colored layer 12 is a colored layer containing a synthetic resin. The colored layer 12 is formed on the surface of the base layer 11 made of synthetic resin. As the base layer 11, a material that can be used for the base material 10 shown in fig. 1 and 2 can be used. The colored layer 12 contains a synthetic resin and a colorant, and has a function of imparting a texture such as a ceramic texture to the surface of the resin product 1. As the synthetic resin and the colorant of the coloring layer 12, materials that can be used for the base material 10 shown in fig. 1 and 2 can be used.

A colored layer may be formed on the rear surface 10b of the substrate 10, and the colored layer may be covered with the coating film 20.

(3) Specific examples of the method for producing a resin product:

fig. 4 schematically illustrates a method of manufacturing a resin product 1 according to an embodiment of the present technology. The manufacturing method includes a base material forming process S1, a coating process S2, and a polishing process S3. In the substrate forming step S1, the substrate 10 including the synthetic resin is formed. In the coating step S2, the coating liquid 25 in which the hollow inorganic particles 40 are dispersed in the resin material 35 to be the synthetic resin 30 is coated on the surface 10a of the base material 10 so that the thickness t of the portion 31 of the coating film 20 where the hollow inorganic particles 40 are absent is 8 μm or more and 0.3a to 1.2 a. Here, the median diameter a of the hollow inorganic particles 40 is 10 to 50 μm, and the true specific gravity of the hollow inorganic particles 40 is 0.55 to 1.20. In the polishing step S3, the surface 20a of the coating film 20 formed on the surface 10a of the substrate 10 is polished so that a part of the hollow inorganic particles 40 is exposed on the surface 20a of the coating film 20.

As described above, the synthetic resin for forming the substrate 10 and the synthetic resin 30 for forming the coating film 20 may be a curable resin such as a thermosetting resin or a thermoplastic resin. The thermosetting resin composition may be an unsaturated polyester resin composition, an acrylic resin composition, an epoxy resin composition, a vinyl ester resin composition, a phenol resin composition, a urea resin composition, a urethane resin composition, a silicone resin composition, a fluororesin composition, a combination of at least some of these resin compositions, or the like. As the transparent thermosetting resin composition for coating film, a resin composition having transparency such as a urethane resin composition including an acrylic urethane resin composition, a polyester urethane resin composition and the like, an unsaturated polyester resin composition, an acrylic resin composition, an epoxy resin composition, a vinyl ester resin composition, a phenol resin composition, a urea resin composition, a silicone resin composition, a fluorine resin composition, a combination of at least some of these resin compositions and the like can be used. As the liquid resin composition, a resin composition containing a polymerizable solution in which at least a polymer is dissolved in a liquid polymerizable monomer or the like can be used. Here, the polymerizable monomer and the like mean: one or more selected from polymerizable monomers and oligomers thereof.

The polymerizable monomer and the like contained in the polymerizable solution may be radical polymerizable monomers and the like which are polymerized by a radical polymerization reaction, and examples of the radical polymerizable monomer and the like include aromatic vinyl compound monomers, acrylate monomers, vinyl compound monomers, allyl compound monomers, oligomers thereof, and the like, and for example, styrene, α -methylstyrene, vinyltoluene, chlorostyrene, dichlorostyrene, tert-butylstyrene, vinylnaphthalene, ethyl vinyl ether, methyl vinyl ketone, methyl methacrylate (also known as MMA), ethyl acrylate, ethyl methacrylate, acrylonitrile, methacrylonitrile, diallyl phthalate, diallyl terephthalate, diallyl succinate, triallyl cyanurate, and oligomers thereof may be used.

As the polymer contained in the polymerizable solution, one or more known polymers contained in a thermosetting resin composition, such as an unsaturated polyester (polyester having an unsaturated group), an acrylic polymer such as a vinyl ester or polyacrylic acid, can be used. The unsaturated polyester can be obtained by, for example, reacting an unsaturated dicarboxylic acid (for example, an unsaturated dibasic acid such as maleic anhydride or fumaric acid) to which a saturated dicarboxylic acid is added with a glycol.

Additives such as a polymerization inhibitor may be added to the polymerizable solution. The polymerization inhibitor may be at least one of hydroquinone, p-benzoquinone, methylhydroquinone, trimethylhydroquinone, t-butylhydroquinone, catechol, t-butylcatechol, 2, 6-di-t-butyl-4-methylphenol, and the like.

In the liquid resin composition containing the polymerizable solution, one or more additives selected from a curing agent, a curing accelerator (curing aid), a thermoplastic polymer, a tackifier, a reinforcing agent, a polymerization regulator, an ultraviolet absorber, a flame retardant, an antioxidant, a light stabilizer and the like may be added within a range not to impair the effects of the present technology. The curing agent may be one or more of organic peroxides, azo compounds, and the like, and for example, one or more of methyl ethyl ketone peroxide, acetylacetone peroxide, tert-butyl peroxybenzoate, benzoyl peroxide, dicumyl peroxide, cumene hydroperoxide, 1,3, 3-tetramethylbutyl peroxy-2-ethylhexanoate, tert-hexyl peroxy-2-ethylhexanoate, azobisisobutyronitrile, and the like may be used. The compounding ratio of the curing agent in the liquid resin composition may be, for example, about 0.1 to 5 parts by weight with respect to 100 parts by weight of the polymerizable solution. As the curing accelerator (curing assistant), one or more of cobalt naphthenate, cobalt octylate (Japanese: オクトエ acid コバルト), N-dimethylaniline, N-diethylaniline, N-dimethyl-p-toluidine, acetylacetone, ethyl acetoacetate, tertiary amine, benzyl dimethylamine, tin octylate, bicyclic amidine compounds, quaternary phosphonium salts, quaternary ammonium salts, and the like can be used.

The liquid resin composition for a substrate may contain a colored additive such as the filler and the colorant. When the filler is used, the mixing ratio of the filler in the liquid resin composition depends on the target hardness of the base material, but is not particularly limited, and may be, for example, about 5 to 600 parts by weight, and more preferably about 10 to 400 parts by weight, based on 100 parts by weight of the polymerizable solution.

The liquid resin composition in the substrate forming step S1 can be molded by casting, coating, cast molding, or the like in which the liquid resin composition is injected into a mold. When the liquid resin composition is curable such as thermosetting, the liquid resin composition having a given shape is cured to form the substrate 10. When the liquid resin composition is thermoplastic, the liquid resin composition having the given shape is cured to form the substrate 10.

The coating liquid 25 is applied to the surface 10a of the obtained substrate 10 so that the thickness t of the portion 31 of the coating film 20 where the hollow inorganic particles 40 are absent is 8 μm or more and 0.3a to 1.2a (coating step S2). The coating liquid 25 is a suspension in which hollow inorganic particles 40 are dispersed in a liquid resin material 35 which is a cured or hardened synthetic resin 30. Fig. 4 shows a semifinished product 2 having a surface 10a of a base material 10 coated with a coating liquid 25 containing a resin material 35 and hollow inorganic particles 40. Since the thickness t of the portion 31 without the hollow inorganic particles 40 is set to 0.3a to 1.2a, the surface 25a of the coating liquid 25 is uneven. At the surface 25a of the coating liquid 25, even at the convex portion where the hollow inorganic particles 40 exist, the covering portion 32 of the resin material 35 covers the hollow inorganic particles 40. Therefore, when the resin material 35 is cured or hardened, the following state is assumed: on the surface of the coating film 20, even at the convex portions where the hollow inorganic particles 40 exist, the covering portions of the synthetic resin 30 cover the hollow inorganic particles 40.

As the resin material 35 contained in the coating liquid 25, the above-mentioned liquid resin composition forming the synthetic resin 30 can be used. As the hollow inorganic particles 40 contained in the coating liquid 25, materials that can be used for the hollow inorganic particles 40 shown in fig. 1 and 2 can be used.

In addition, in order to reduce the viscosity of the liquid resin material 35, a volatile solvent may be added to the resin material 35. As the solvent having volatility, an organic solvent such as a hydrocarbon solvent or an ether solvent can be used. As the hydrocarbon solvent, one or more of toluene, xylene, heptane, and the like can be used. As the ether solvent, one or more of dibutyl ether, ethylene glycol monobutyl ether, and the like can be used.

The mixing ratio of the hollow inorganic particles 40 in the coating liquid 25 depends on the particle diameter of the hollow inorganic particles 40 and the thickness t, and may be, for example, about 0.5 to 20 parts by weight, and more preferably about 1 to 10 parts by weight, based on 100 parts by weight of the polymerizable solution.

The coating of the coating liquid 25 may be performed by spraying, roll coating (japanese: ロールコーティング), brush coating, knife coating, roll coating (japanese: ローラー coating り), a combination of at least some of these methods, or the like. The amount of the coating liquid 25 to be applied may be such that the thickness t of the portion 31 of the coating film 20 where the hollow inorganic particles 40 are absent is 8 μm or more and 0.3a to 1.2 a.

When the resin material 35 is curable, the coating liquid 25 is applied to the substrate 10, and then the resin material 35 is cured to form the coating film 20 from the coating liquid 25. When the resin material 35 is thermosetting, the semi-finished product 2 may be heated to promote curing of the resin material 35. The heating conditions are not particularly limited, and may be, for example, about 50 to 60 ℃ for about 1 to 2 hours. When the resin material 35 contains a volatile solvent, the solvent is volatilized after the coating liquid 25 is applied. When the resin material 35 is thermoplastic, if the coating liquid 25 in which the hollow inorganic particles 40 are dispersed in the molten resin material 35 is used for coating and the temperature of the resin material 35 after coating is lowered, the resin material 35 is cured, and thus the coating liquid 25 becomes the coating film 20. On the surface of the coating film 20 before polishing, the hollow inorganic particles 40 are covered with the cured or hardened synthetic resin 30 at the convex portions where the hollow inorganic particles 40 exist.

The surface of the formed coating film 20 is polished to expose a part of the hollow inorganic particles 40 on the surface 20a of the coating film 20 (polishing step S3). Thus, the resin product 1 shown in FIGS. 1 to 3 is formed. The surface of the coating film 20 can be ground by grinding with sandpaper, buffing grinding, belt grinding, a combination of at least some of these, or the like. The grinding with the sandpaper can be performed manually or mechanically, for example, by sticking sandpaper having a grain size of about 500 to 3000 mesh, more preferably about 1000 to 2000 mesh, to a lath. As the polishing and grinding, a disk polisher, a double-head grinder, or the like can be used. As the polishing wheel, a polishing wheel of cotton, flannel, or the like may be used. As the abrasive for polishing and grinding, wax in a solid or liquid state can be used. In order to remove the synthetic resin 30 covering the hollow inorganic particles 40 at the convex portions of the surface of the coating film 20, it may be polished with sandpaper, and in order to improve the gloss of the exposed hollow inorganic particles 40, it may be polished.

In the case of manufacturing the resin product 1 having the colored layer 12 as shown in fig. 3, after the base layer 11 is formed in the base material forming step S1 by the above-described method, a coating liquid for the colored layer may be applied to the surface of the base layer 11 to form the colored layer 12 including the cured or hardened synthetic resin and the coloring agent. In the coating step S2, the coating liquid 25 is applied to the surface of the colored layer 12, and the surface of the coating film 20 is polished in the polishing step S3.

In the present manufacturing method, since the coating liquid 25 is applied so that the thickness t of the portion 31 of the coating film 20 where the hollow inorganic particles 40 are absent is 8 μm or more, a uniform coating film 20 is formed. Thus, the resin product 1 having excellent surface strength and design properties is obtained. The resin product 1 having a good surface design can be obtained by setting the median diameter a of the hollow inorganic particles 40 to 10 to 50 μm. Since the hollow inorganic particles 40 having a true specific gravity of 0.55 to 1.20 are stably dispersed in the coating liquid 25, a uniform coating film 20 in which the hollow inorganic particles 40 are well dispersed in the synthetic resin 30 is formed. Further, since the thickness t is 0.3a to 1.2a, a large amount of the hollow inorganic particles 40 that are held by the synthetic resin 30 without falling off are exposed by polishing, and the resin product 1 having excellent abrasion resistance and scratch resistance is obtained. The matte effect due to the irregularities on the surface 20a of the coating film 20 and the glossy effect due to the polished outer shape of the hollow inorganic particles 40 cooperate with each other, and the resin product 1 has good design properties such as a ceramic texture and high surface hardness.

Here, even if the surface of the resin product 1 is damaged, the damage of the substrate 10 is suppressed by the hard hollow inorganic particles 40 in a dispersed state. In addition, in a state where a part of the hollow inorganic particles 40 is exposed on the surface 20a of the coating film 20, the synthetic resin 30 is not conspicuous as a scratch even if it is damaged. In particular, when the synthetic resin 30 has transparency, the scratch is less noticeable.

As described above, the present specific example can provide a high-quality resin product with inconspicuous scratches and a method for producing the same.