JP5730620B2 - Fluororesin coated artificial marble and artificial marble kitchen sink - Google Patents

Description

  The present invention relates to an artificial marble coated with a transparent fluororesin film. In particular, it relates to a kitchen sink made of artificial marble coated with a transparent fluororesin film.

  Artificial marble refers to a material that is made into a marble tone with a synthetic resin such as vinyl ester resin, acrylic resin, or polyester resin as a main component and various inorganic fillers. Artificial marble is used in wash counters, kitchen counters, bathtubs, wash bowls, and so on. For this reason, artificial marble is required to have scratch resistance and antifouling performance (a property that makes it difficult to get dirt and easily removes dirt).

  In order to improve the antifouling performance of artificial marble, it has been proposed to form a transparent coating on the surface of the artificial marble. For example, an artificial marble coated with an acrylic paint containing a siloxane-based water repellent is known. (For example, refer to Patent Document 1).

  In addition, there is a known technology that improves the anti-contamination property by forming a fluororesin film on the surface of kitchen components such as kitchen sinks, and a device that improves the adhesion of the fluororesin coating to kitchen components has also been proposed. (For example, refer to Patent Document 2). Furthermore, the device which forms the membrane | film | coat containing a silica and a fluororesin particle on the surface of the member for kitchens, and improves a damage resistance is also proposed (refer patent document 3).

  On the other hand, a resin-coated stainless steel plate in which a transparent fluororesin film is formed on a stainless steel plate is known. The transparent fluororesin film contains a scaly inorganic additive, polytetrafluoroethylene powder, and a base resin (see Patent Documents 4 and 5).

JP 2006-88122 A JP 2009-197145 A JP 2006-346047 A JP 2001-137775 A JP 2001-205182 A

  As described above, artificial marble is required to have scratch resistance and antifouling performance, but a resin film that satisfies these requirements is not provided. In other words, if a large amount of an inorganic additive is added to the resin film, the film surface strength is increased and the scratch resistance performance is improved; on the other hand, the film surface may vary depending on the inorganic additive, so the antifouling performance is reduced. There are things to do.

  Therefore, the present invention provides scratch resistance to the artificial marble by adjusting the content (material, shape, amount added) of the additive contained in the transparent fluororesin film formed on the surface of the artificial marble, and preferably the thickness of the fluororesin film. The purpose is to give the attachment performance and antifouling performance. Another object of the present invention is to improve the adhesion of the transparent fluororesin film to the artificial marble by optimizing the base resin of the fluororesin film formed on the surface of the artificial marble so that it is difficult to peel off. .

That is, the first of the present invention relates to the following fluororesin-coated artificial marble.
[1] It has an artificial marble and a transparent fluororesin coating film formed on the surface of the artificial marble,
The transparent fluororesin coating film is dispersed in 100 parts by mass of fluorine-based resin solids and the fluorine-based resin, and 3-9 mass of a flaky inorganic additive having an average particle diameter of 10-15 μm and an average thickness of 0.4-7 μm. And fluorine resin-coated artificial marble dispersed in the fluorine-based resin and containing 4.5 to 13.5 parts by mass of an additive for fluororesin lubrication having an average particle size of 2.5 to 4.5 μm.

［式（１）において、
Ｒ^１およびＲ^２は、それぞれ独立して、炭素数１〜６のアルキル基、−(ＣＨ_２)_ｍ−ＯＯＣ(ＣＨ_３）Ｃ＝ＣＨ_２、−(ＣＨ_２)_ｍ−ＯＯＣＣＨ＝ＣＨ_２または−ＣＨ＝ＣＨ_２を表し、ｍは１〜６を表すが、
Ｒ^１およびＲ^２の何れか一方または両方が、−(ＣＨ_２)_ｍ−ＯＯＣ(ＣＨ_３）Ｃ＝ＣＨ_２、−(ＣＨ_２)_ｍ−ＯＯＣＣＨ＝ＣＨ_２または−ＣＨ＝ＣＨ_２であり、
ｎは１〜４２０を表す]
［３］前記鱗片状無機質添加剤がガラスフレークであり、かつ前記フッ素樹脂潤滑用添加剤がポリテトラフルオロエチレンの粒子の凝集粒子である、［１］または［２］に記載のフッ素樹脂コート人造大理石。
［４］前記ポリテトラフルオロエチレンの粒子は、分子量 ５万〜１０万 のポリテトラフルオロエチレンの未焼成粒子である、請求項３に記載のフッ素樹脂コート人造大理石。
［５］前記透明フッ素樹脂塗膜の厚みは、５〜２０μｍである、［１］〜［４］の何れかに記載のフッ素樹脂コート人造大理石。 [2] The fluorine-based resin is a fluorine containing vinylidene fluoride, tetrafluoroethylene, a reactive silicone oil represented by the following general formula (1), a hydroxyl group-containing vinyl ether, and an unsaturated carboxylic acid as monomer components. The fluororesin-coated artificial marble according to [1], which is a cured product of a copolymer.

[In Formula (1),
R ¹ and R ² are each independently an alkyl group having 1 to 6 carbon atoms, — (CH ₂ ) _m —OOC (CH ₃ ) C═CH ₂ , — (CH ₂ ) _m —OOCCH═CH ₂ or -CH = CH ₂ and m represents 1-6,
Either one or both of R ¹ and R ² is — (CH ₂ ) _m —OOC (CH ₃ ) C═CH ₂ , — (CH ₂ ) _m —OOCCH═CH ₂ or —CH═CH ₂ ;
n represents 1-420]
[3] The fluororesin-coated artificial structure according to [1] or [2], wherein the scale-like inorganic additive is glass flake, and the fluororesin lubricating additive is an aggregated particle of polytetrafluoroethylene particles. marble.
[4] The fluororesin-coated artificial marble according to claim 3, wherein the polytetrafluoroethylene particles are unbaked particles of polytetrafluoroethylene having a molecular weight of 50,000 to 100,000.
[5] The fluororesin-coated artificial marble according to any one of [1] to [4], wherein the transparent fluororesin coating film has a thickness of 5 to 20 μm.

The second of the present invention relates to the following kitchen artificial marble.
[6] An artificial marble kitchen sink including the fluororesin-coated artificial marble according to any one of [1] to [5], wherein the transparent fluororesin coating film is formed on an inner surface of the sink. , Artificial marble kitchen sink.

  The present invention provides a fluororesin-coated artificial marble excellent in scratch resistance and antifouling properties. The fluororesin-coated artificial marble of the present invention can be preferably used for a kitchen sink in which damage is likely to be a problem.

It is a figure which shows the outline | summary of the fluororesin coating film of the fluororesin coat artificial marble of this invention. It is a figure which shows the outline | summary of the kitchen counter which has a kitchen sink as an example. It is a figure which shows the outer shape of the kitchen sink as an example.

1. TECHNICAL FIELD The present invention relates to a fluororesin coated artificial marble having an artificial marble and a transparent fluororesin coating film covering the artificial marble. Artificial marble is a resin molding containing a synthetic resin and an inorganic additive.

  The synthetic resin constituting the artificial marble may be a thermosetting resin or a thermoplastic resin. Examples of synthetic resins constituting the artificial marble include polyester resins, acrylic resins, vinyl ester resins, and mixed resins thereof.

  Examples of inorganic additives contained in the artificial marble include, but are not limited to, calcium silicate, talc, kaolin, clay, silica, calcium carbonate, aluminum hydroxide, magnesium hydroxide, barium sulfate, calcium sulfate and the like. Among those exemplified, aluminum hydroxide is preferable, and aluminum hydroxide trihydrate, that is, gibbsite is more preferable. Since gibbsite is close to the bending rate of methyl methacrylate polymer, it provides excellent transparency and contributes to imparting heat resistance and flame retardancy to artificial marble formed as a hydrate characteristic.

  The average particle size of the inorganic powder as the inorganic additive is preferably 0.1 to 100 μm, and more preferably 0.5 to 80 μm.

  In the artificial marble, the ratio of the synthetic resin to the inorganic additive is preferably 50 to 500 parts by mass with respect to 100 parts by mass of the synthetic resin.

  The artificial marble may contain additives such as a colorant and a pattern material as necessary. The colorant may be any colorant that is usually used for resin moldings containing inorganic powder with artificial marble, such as dyes, organic pigments, and inorganic pigments. Examples of the pattern material include particles made of an organic resin or inorganic particles. Examples of the organic resin include methyl methacrylate resin, polystyrene, polyvinyl chloride, polyester, epoxy resin, polyvinyl alcohol, and the like. Examples of inorganic particles include marble particles, silica, mica and the like. The size of these additives is preferably 10 mm or less, and more preferably 5 mm or less.

  The surface of the artificial marble may be polished or degreased.

2. Transparent fluororesin coating The surface of the artificial marble is coated with a transparent fluororesin coating. The entire surface of the artificial marble may be covered with a transparent fluororesin coating film, or a part thereof may be covered with a transparent fluororesin coating film. Moreover, the transparent fluororesin coating film may be formed only on one side of the artificial marble, or may be formed on both sides. For example, when providing a kitchen sink, it is preferable to coat the inner surface of the sink with a transparent fluororesin coating film. The fluororesin coating film is transparent, but need not be colorless and transparent, and may be transparent so that the surface of the artificial marble can be visually recognized.

  The transparent fluororesin coating film is preferably in direct contact with the surface of the artificial marble. That is, it is preferable that no other layer is interposed between the artificial marble and the transparent fluororesin coating film. In the present invention, the transparent fluororesin coating film can have sufficient adhesion to the surface of the artificial marble.

  The transparent fluororesin coating film contains a fluorine base resin, a scaly inorganic additive, and a fluororesin lubricant. FIG. 1 is a diagram schematically showing a transparent fluororesin coating film. As shown in FIG. 1, there is a transparent fluororesin coating film 2 on the surface of the artificial marble 1. In the transparent fluororesin coating film 2, a fluorine base resin, a scale-like inorganic additive 3 dispersed in the fluorine base resin, a fluororesin lubricant 4 and an optional matting agent 5 are dispersed; Are uniformly dispersed.

The fluorine-based resin is preferably a cured product of a fluorine copolymer containing at least vinylidene fluoride and tetrafluoroethylene as monomer components. Vinylidene fluoride is a compound represented by the following formula (A), and tetrafluoroethylene is a compound represented by the following formula (B).

  By including tetrafluoroethylene as a monomer component of the fluorine copolymer, the surface friction coefficient of the fluorine-based resin can be reduced and the mechanical strength can be increased. Further, by combining vinylidene fluoride as a monomer component, the moldability of the fluorine-based resin can be improved.

  As a monomer component of the fluorine copolymer, a fluorine-containing monomer other than vinylidene fluoride and tetrafluoroethylene may be further included. Examples of other fluorine-containing monomers include chlorotrifluoroethylene and hexafluoropropylene.

  The ratio of the fluorine-containing monomer (total of vinylidene fluoride and tetrafluoroethylene, etc.) in the monomer component of the fluorine copolymer is 30 to 80 mol%.

  More preferably, the fluorine copolymer of the fluorine-based resin is obtained by copolymerizing a reactive silicone oil, a hydroxyl group-containing vinyl ether, and an unsaturated carboxylic acid together with a fluorine-containing monomer such as vinylidene fluoride or tetrafluoroethylene. It is a fluorine copolymer. By copolymerizing these components, the adhesion of the transparent fluororesin coating film to the artificial marble can be enhanced.

The reactive silicone oil that is a monomer component of the fluorine copolymer of the fluorine-based resin is preferably terminal-modified polydimethylsiloxane as represented by the following formula (1).

In said formula (1), n represents 1-420. In the above formula (1), R ¹ and R ² are each independently an alkyl group having 1 to 6 carbon atoms, — (CH ₂ ) _m —OOC (CH ₃ ) C═CH ₂ , — (CH _2). ) represents the _m -OOCCH = CH ₂ or -CH = CH _2. Here, m represents 1-6.

However, either one or both of R 1 and R 2, it is necessary to include polymerizable functional groups, either or both of R 1 and R 2, - (CH 2) m -OOC (CH 3) C = CH 2, - a (CH 2) m -OOCCH = CH 2 or -CH = CH 2. Preferably, one of R 1 and R 2 is — (CH 2 ) m —OOC (CH 3 ) C═CH 2 or — (CH 2 ) m —OOCCH═CH 2 , or R 1 and Both R 2 are — (CH 2 ) m —OOC (CH 3 ) C═CH 2 . That is, the reactive silicone oil is preferably a modified polydimethylsiloxane having one or both ends modified with (meth) acryl.

  A reactive silicone oil may be used individually by 1 type, and may be used in combination of 2 or more type.

  The ratio of the reactive silicone oil in the monomer component of the fluorine copolymer of the fluorine-based resin is 0.005 to 25 mol%.

  The hydroxyl group-containing vinyl ether that is a monomer component of the fluorine copolymer of the fluorine-based resin is preferably a hydroxyalkyl vinyl ether, and the hydroxyalkyl may have 2 to 6 carbon atoms. Examples of the hydroxyl group-containing vinyl ether include 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, and the like. In particular, 2-hydroxyethyl vinyl ether and 4-hydroxybutyl vinyl ether are preferable. The ratio of the hydroxyl group-containing vinyl ether in the monomer component of the fluorine copolymer of the fluorine-based resin is 10 to 40 mol%.

  Examples of the unsaturated carboxylic acid that is a monomer component of the fluorine copolymer of the fluorine-based resin include acrylic acid, methacrylic acid, maleic acid, 3-butenoic acid, and 4-pentenoic acid. Methacrylic acid is preferred. The ratio of the unsaturated carboxylic acid in the monomer component of the fluorine copolymer of the fluorine-based resin is 0.5 to 20 mol%.

  A commercially available fluorine copolymer obtained by copolymerizing a reactive silicone oil, a hydroxyl group-containing vinyl ether, and an unsaturated carboxylic acid together with a fluorine-containing monomer such as vinylidene fluoride or tetrafluoroethylene may be used.

  The fluorine-based resin constituting the transparent fluororesin coating film is a cured product of a fluorine copolymer. The cured product is a resin that is heat-cured or photocured with a curing agent. The curing agent is not particularly limited and may be an isocyanate curing agent.

  The transparent fluororesin coating film contains a scaly inorganic additive. The scaly inorganic additive is preferably glass flakes, but part of the scaly inorganic additive may be glass beads or silicon carbide powder.

  It is preferable that the average particle diameter (simple average of the longest diameter) of the glass flakes which are scale-like inorganic additives is 10-15 micrometers. If the average particle size of the glass flakes is less than 10 μm, the film hardness of the transparent fluororesin coating film may not be sufficiently increased. On the other hand, when the average particle size of the glass flakes exceeds 15 μm, the surface smoothness of the transparent fluororesin coating film may be lowered, and the antifouling property may be lowered.

  It is preferable that the average thickness of the glass flake which is a scale-like inorganic additive is 0.4-7 micrometers. If the average thickness of the glass flakes is less than 0.4 μm, the film hardness of the transparent fluororesin coating film may not be sufficiently increased. On the other hand, when the average thickness of the glass flakes exceeds 7 μm, the surface smoothness of the transparent fluororesin coating film may be lowered, and the antifouling property may be lowered.

The average particle size of the glass flakes is meant an average particle size D ₅₀ as measured by laser diffraction scattering. The average thickness may be measured using an interference microscope or the like.

  The ratio of the scale-like inorganic additive in the transparent fluororesin coating film is preferably 3 to 9% by mass with respect to the fluororesin. When there is too little addition amount of a scale-like inorganic additive, the film | membrane intensity | strength of a transparent fluororesin coating film cannot fully be raised. On the other hand, if the amount of the scaly inorganic additive is too large, the smoothness of the film surface of the fluororesin coating film may be reduced, which may impair the aesthetic appearance of the artificial marble and may reduce the antifouling property. .

  The transparent fluororesin coating film contains an additive for lubricating fluororesin. The fluororesin lubricating additive is fluororesin particles, typically polytetrafluoroethylene particles.

The average particle diameter of the fluororesin lubricating additive is preferably 2.5 to 4.5 μm. If the average particle diameter of the fluororesin lubrication additive is less than 2.5 μm, the strength as particles may not be sufficient, and the surface lubricity of the fluororesin coating film may not be sufficiently obtained. On the other hand, when the average particle diameter of the fluororesin lubricant exceeds 4.5 μm, the smoothness of the coating surface of the fluororesin coating film is lowered and the appearance is deteriorated. The average particle diameter of the fluororesin lubricant additive means the average particle diameter D ₅₀ measured by a laser diffraction scattering.

  The ratio of the fluororesin lubricating additive in the transparent fluororesin coating film is preferably 4.5 to 13.5% by mass with respect to the fluororesin. When the additive ratio of the fluororesin lubrication additive is less than 4.5% by mass, the lubricity of the transparent fluororesin coating film may be insufficient, and sufficient scratch resistance may not be obtained. On the other hand, when the addition ratio of the fluororesin lubricant exceeds 13.5% by mass, the fluororesin lubricant is likely to be exposed on the surface of the transparent fluororesin coating film, which may impair the appearance of the artificial marble. It may reduce the antifouling property. Moreover, when there is too much addition ratio of a fluororesin lubricant, there exists a possibility that the adhesiveness to the artificial marble of a fluororesin coating film may fall, or coating-film intensity | strength may fall.

  Polytetrafluoroethylene particles as an additive for lubricating fluororesin include fired particles and unfired particles. The fired particles of polytetrafluoroethylene are those obtained by compression molding while firing polytetrafluoroethylene that has been subjected to suspension polymerization. The fired particles are hard and not easily crushed, and are easily dispersed in the resin.

  On the other hand, the unsintered particles of polytetrafluoroethylene are formed by molding polytetrafluoroethylene polymerized by emulsion polymerization. Unsintered particles are soft and easily deformed, and may exist as secondary particles that are aggregates of primary particles. Accordingly, the unsintered particles can be dispersed in the resin to form primary particles. Since the primary particles are small and difficult to settle, they are likely to be present on the surface of the fluororesin coating film.

  Polytetrafluoroethylene is classified into a low molecular weight type (about 40 to 50,000) having a molecular weight of several tens of thousands and a high molecular weight type having a molecular weight of nearly 100,000; the high molecular weight type is more resistant to fluororesin coatings. It may be easy to impart abrasion. Therefore, it is preferable that the molecular weight of polytetrafluoroethylene is 50,000 to 100,000.

  Some of the polytetrafluoroethylene particles are commercially available, and there is “KTL-8F (Kitamura Co., Ltd.)” as a low molecular weight type polytetrafluoroethylene particle which is an unsintered particle. As a high molecular weight type polytetrafluoroethylene particle, “KTL-8FH (Kitamura Co., Ltd.)” is known.

  The transparent fluororesin coating film may further contain an optional component. Examples of optional components include a matting agent, a fluororesin lubricant dispersant, and a leveling agent. The matting agent is hydrophobic silica or the like.

  The thickness of the transparent fluororesin coating film is preferably 5 to 20 μm, and more preferably 5 to 15 μm. When the thickness of the transparent fluororesin coating film is less than 5 μm, the film durability is lowered, the coating film is peeled off, and the scratch resistance cannot be sufficiently obtained. In addition, if the thickness of the transparent fluororesin coating film is too small, additives (such as scale-like inorganic additives and fluororesin lubricants) are likely to be present on the surface of the coating film, the aesthetic appearance is likely to be impaired, and the antifouling property is also reduced. Cheap. On the other hand, if the thickness of the transparent fluororesin coating film exceeds 20 μm, the appearance (color / gloss) of the artificial marble may be impaired. That is, when the transparent fluororesin coating film is thick, the gloss and depth of the coating film are excessively increased, so that it is difficult to maintain the appearance of the artificial marble itself. Furthermore, if the thickness of the transparent fluororesin coating film is too large, additives (such as scale-like inorganic additives and fluororesin lubricants) may settle inside the film, resulting in a decrease in scratch resistance.

3. Production of fluororesin coated artificial marble The method for producing the fluororesin coated artificial marble of the present invention is not particularly limited; for example, obtaining a molded article of artificial marble, applying a fluororesin composition to the molded article, And heating the molded article coated with the fluororesin composition in a drying furnace.

  The molded product of artificial marble is obtained, for example, by heat-pressing a resin composition with a mold. The molding method is not particularly limited.

  The fluororesin composition to be applied to the molded product includes 100 parts by mass of a fluorine-based resin solid content, 3 to 9 parts by mass of a flaky inorganic additive having an average particle diameter of 10 to 15 μm and an average thickness of 0.4 to 7 μm, and an average It contains 4.5 to 13.5 parts by mass of an additive for lubricating a fluororesin having a particle size of 2.5 to 4.5 μm. Furthermore, the fluororesin composition to be applied contains a curing agent, and preferably further contains a solvent.

  Fluorine-based resins are often obtained as semi-liquid compositions. The content of the fluorine-based resin solid content in the semi-liquid fluorine-based resin composition is not particularly limited, but is about 30 wt%. The amount of the scaly inorganic additive is 0.9 to 2.7 parts by mass and the amount of the fluororesin lubricant additive is 1.35 with respect to 100 parts by mass of the semi-liquid composition having a solid content of 30 wt%. It will be -4.05 mass part.

  The curing agent is not particularly limited, but an isocyanate curing agent may be used. Examples of isocyanate curing agents include aromatic diisocyanates such as aromatic diisocyanates such as tolylene diisocyanate and diphenylmethane diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate, and xylylene diisocyanate. Diisocyanates and their blocked isocyanates are included. The solvent is preferably a solvent that dissolves solid components and has a boiling point of 180 to 210 ° C.

  In order to apply the fluororesin composition to the obtained molded article, a technique such as dipping, spin coating, spray coating or the like may be used, but generally a spray coating method is employed. The molded article to which the resin composition is applied is heated in a drying furnace, and may be treated at 90 ° C. for 1 hour, for example.

4). Use of fluororesin-coated artificial marble The fluororesin-coated artificial marble of the present invention can be used for any application, but can be preferably used for, for example, a wash counter, a kitchen counter, a bathtub, and a wash bowl. The surface coated with the fluororesin of the fluororesin-coated artificial marble of the present invention has both high scratch resistance and antifouling properties, and therefore is preferably used as a sink, and particularly preferably used as a kitchen sink.

  More specifically, the sink made of the artificial marble of the present invention preferably has a fluororesin coating film formed on the inner surface of the sink. The inner surface of the sink is easily damaged by contact with dishes cleaned inside the sink, and is also easily contaminated by cooking oil. On the other hand, since the fluororesin-coated artificial marble of the present invention has high scratch resistance and antifouling properties, it effectively suppresses scratches and contamination on the inner surface of the sink.

  FIG. 2 shows an outline of an example of the kitchen counter 10 including a sink. The kitchen counter 10 includes a sink 11 and a top plate 12. FIG. 3 is a perspective view showing only the sink 11. The fluororesin coating film is preferably formed on the entire inner surface 20 of the sink 11. Of course, a fluororesin coating film may be formed on the upper surface 21 of the top plate 12 or the like.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the technical scope of the present invention is not construed as being limited thereto.

The composition of the artificial marbles 1 and 2 used in the examples is shown.

The fluororesin coating film components used in the examples will be described.
[About fluorine-based resin]
(1) Fluorine-based resin 1: synthesized by the following method. Vinylidene fluoride, tetrafluoroethylene, a reactive silicone oil represented by the formula (1), a hydroxyl group-containing vinyl ether, and an unsaturated carboxylic acid are included as monomer components.
(2) Fluorine-based resin 2: Synthesized by the following method. Vinylidene fluoride and tetrafluoroethylene are included as monomer components, but the reactive silicone oil represented by the formula (1) is not included as a monomer component.
(3) Fluorine-based resin 3 (Defensor TR-310, DIC): A two-component mixed resin containing an acrylic resin and a fluorine-based resin.
(4) Fluorine base resin 4 (OPC-800, NI Material)

(Synthesis of fluorine-based resin 1)
After degassing into a stainless steel autoclave with a stirrer (pressure resistance 100 kg / cm ² ), 96 g vinylidene fluoride, 81 g tetrafluoroethylene, 69.6 g hydroxybutyl vinyl ether, 2.2 g acrylic acid, structural formula CH ₂ ═C (CH _{3) -COO-C 3 H 6} -Si (CH 3) 2 - [O-Si (CH 3) 2] 44 -OSi (CH 3) methacryl-modified silicone oil 10.5g represented by _3, butyl acetate 200 ml, 200 ml of n-butanol and 1.3 g of t-butyl peroxypivalate were added, and the internal temperature was raised to 60 ° C. while stirring. Thereafter, the reaction was continued with stirring, and stirring was stopped after 20 hours to complete the reaction.

  Further, the obtained polymerization solution was concentrated to obtain a 50% butyl acetate / n-butanol mixed solution. Further, Coronate HX [manufactured by Nippon Polyurethane Industry Co., Ltd.] was added to this solution so that the hydroxyl group / NCO group of the polymer was 1/1 to prepare a fluorine-based resin 1.

(Synthesis of fluorine-based resin 2)
After deaeration in a stainless steel autoclave with a stirrer (withstand pressure of 100 kg / cm ² ), 96 g of vinylidene fluoride, 81 g of tetrafluoroethylene, 69.6 g of hydroxybutyl vinyl ether, 2.2 g of acrylic acid, 200 ml of butyl acetate, 200 ml of n-butanol Then, 1.3 g of t-butyl peroxypivalate was added, and the internal temperature was raised to 60 ° C. while stirring. Thereafter, the reaction was continued with stirring, and stirring was stopped after 20 hours to complete the reaction.

  Further, the obtained polymerization solution was concentrated to obtain a 50% butyl acetate / n-butanol mixed solution. Further, Coronate HX [manufactured by Nippon Polyurethane Industry Co., Ltd.] was added to this solution so that the hydroxyl group / NCO group of the polymer was 1/1 to prepare a fluorine-based resin 2.

[Other ingredients]
Wax (copolymer of polyethylene and PTFE) CERAFLOUR 997, BYK Japan, average particle size 7μm
Resin beads 1 (melamine resin) 6500M, Nissan Chemical Industries, average particle size 6.9μm
Resin beads 2 (melamine resin) 10500M, Nissan Chemical Industries, average particle size 10.9μm
Matting agent (hydrophobic silica) SS-50, Tosoh silica, average particle size 1.5μm
PTFE dispersant DISPERBYK-111, BYK Japan Leveling agent BYK-378, BYK Japan

  The following fluororesin composition (paint) was prepared. Numerical values in Tables 4 to 5 represent parts by mass. A specific adjustment procedure was to add a PTFE dispersant to the base resin and uniformly stir, and then add PTFE particles and stir. Glass flakes (wax, resin beads) were added to the resulting stirred product and stirred. Further, after adding a matting agent and stirring, mill dispersion was performed. After adding a leveling agent and stirring uniformly, mesh filtration of the mixture was performed. The solid content (nonvolatile content) was measured and adjusted (corrected) to about 30% with a mixed solvent. In this way, a fluororesin paint was obtained.

  The mass part of the base resin indicates the mass part as a semi-liquid fluororesin paint. The value in parenthesis indicates the mass part of the base resin solid content.

[Example 1-1]
The artificial marble 1 was molded into a sink shape with a plate thickness of 6 mm. The surface of the obtained molded body was washed with isopropyl alcohol. The fluororesin paint having the composition shown in Example 1 in Table 4 was spray-applied to the inner surface of the sink-shaped sink. Thereafter, the coated film was dried at a reaching material temperature of 90 ° C. for 60 minutes, and then allowed to stand at room temperature for 1 day to complete the curing, and the artificial marble sink having a matte transparent fluororesin coating film having a film thickness of 10 μm was formed. Got.

[Example 1-2]
An artificial marble sink was obtained in the same manner as in Example 1-1 except that the artificial marble 1 was replaced with the artificial marble 2.

[Examples 2 to 8]
An artificial marble sink was obtained in the same manner as in Example 1-1 except that the fluororesin paint was replaced with a fluororesin paint having the formulation shown in Examples 2 to 8 in Table 4.

[Reference Examples 1 to 4]
An artificial marble sink was obtained in the same manner as in Example 1-1 except that the fluororesin paint was replaced with the fluororesin paint having the composition shown in Reference Examples 1 to 4 in Table 4. The fluororesin paints of the formulations shown in Reference Examples 1 to 4 are made of a fluorine-based resin and do not contain additives.

[Comparative Examples 1 to 10]
An artificial marble sink was obtained in the same manner as in Example 1-1 except that the fluororesin paint was replaced with a fluororesin paint having the composition shown in Comparative Examples 1 to 10 in Table 5. The fluororesin paints of the formulations shown in Comparative Examples 1 to 10 do not contain glass flakes (scale-like inorganic additives).

[Comparative Example 11]
A molded body to which no fluororesin paint was applied was used as a sample.

  Test pieces were cut out from the kitchen artificial marble sinks obtained in each of the examples and comparative examples, and subjected to a hot water resistance test, an abrasion test, an antifouling test (oil-based magic repeatability), and an appearance check. The results are shown in Table 6.

[Hot water resistance test]
The test piece was poured into warm water at 80 ° C., taken out after being immersed for 168 hours, naturally cooled, and returned to room temperature. Thereafter, 100 cuts having a grid shape of 1 mm width were made using a cutter knife until reaching the substrate. A 12 mm wide cellophane tape made by Nichiban was applied and rubbed well with nails. The cellophane tape was peeled off 90 degrees at a stretch. This operation was peeled twice in total, once in the vertical and horizontal directions, and the coating film adhesion was evaluated.
◎: No peeling ○: The number of peeling parts per 100 grid cuts is 10 or less △: The number is 10 or more and 50 or less ×: The number exceeds 50

[Abrasion resistance test]
A weight (6 kg) corresponding to the inner volume was placed in a SUS430 stainless steel bowl having an outer diameter of 30 cm and a bottom area of 242 cm ² or more. A SUS scissors was placed on the surface of the test piece and repeatedly worn at a stroke of 50 mm and a speed of 20 reciprocations / minute. After 500 reciprocations, the SUS cage was removed, and the appearance of the test piece surface was confirmed. When there were no significant scratches and the appearance design was maintained, the evaluation was repeated 1000 round trips and 2500 round trips.
◎: No flaws and no change in design properties ○: Although fine flaws are generated, the design properties are maintained △: Scratches are generated and the design properties are slightly lowered ×: Remarkably flaws are generated and the design properties are remarkably impaired

[Anti-fouling test]
Immediately after the surface of the test piece was painted with oily magic, it was removed by dry wiping with Kimwipe (S-200). This was repeated 20 times to evaluate the magic removability.
◎: No trace at all ○: Trace remains very slightly △: Trace remains quite conspicuous ×: Trace remains completely

[Appearance check]
Visually evaluate the appearance of the painted surface.
○: Good △: Slightly rough feeling ×: Poor

[Evaluation results]
In Example 1-1, Example 1-2, and Examples 2 to 8, the fluororesin coating film has high resistance to hot water and the fluororesin coating film has sufficient wear resistance. Furthermore, it is understood that the antifouling property is high and the beauty is maintained. On the other hand, when there is no fluororesin coating film as in Comparative Example 11, the wear resistance and antifouling property are remarkably inferior.

  As shown in Reference Examples 1 to 4, when the fluorine base resin 1 or the fluorine base resin 2 is used as the fluorine base resin, it has high resistance to hot water; the fluorine base resin 1 has particularly high antifouling properties. Recognize. Thus, the fluorine-based resin is “a fluorine copolymer containing vinylidene fluoride, tetrafluoroethylene, a reactive silicone oil represented by the following general formula (1), a hydroxyl group-containing vinyl ether, and an unsaturated carboxylic acid as monomer components. It can be seen that both adhesion and antifouling properties can be achieved.

  In Comparative Examples 1 to 10, all of the fluororesin coatings had sufficient hot water adhesion, but since glass flakes (flaky inorganic additives) were not included, the abrasion resistance was sufficient. There wasn't. In particular, the wear resistance decreased when the PTFE particles were fired particles (Comparative Examples 2 to 5), but when the PTFE particles were unfired particles, a certain level of wear resistance was exhibited.

  According to the present invention, a fluororesin-coated artificial marble having scratch resistance and antifouling performance is provided. The fluororesin-coated artificial marble of the present invention is particularly suitably applied to a sink.

1 artificial marble 2 transparent fluororesin coating film 3 scale-like inorganic additive 4 fluororesin lubricant 5 matting agent 10 kitchen counter 11 sink 12 top plate 20 inner surface 21 upper surface

Claims (4)

An artificial marble, and a transparent fluororesin coating film formed on the surface of the artificial marble,
The transparent fluororesin coating film is
100 parts by mass of fluorine-based resin solids,
Dispersed in the fluorine-based resin, 3-9 parts by weight of a scaly inorganic additive having an average particle size of 10-15 μm and an average thickness of 0.4-7 μm;
4.5 to 13.5 parts by mass of an additive for lubricating fluororesin having an average particle size of 2.5 to 4.5 μm dispersed in the fluorine base resin;
Only including,
The scaly inorganic additive is glass flakes,
The fluororesin lubricating additive is an aggregated particle of unsintered particles of polytetrafluoroethylene having a molecular weight of 50,000 to 100,000.
Fluoropolymer coated artificial marble. The fluorine-based resin includes, as monomer components, vinylidene fluoride, tetrafluoroethylene, a reactive silicone oil represented by the following general formula (1), a hydroxyl group-containing vinyl ether, and an unsaturated carboxylic acid. Is a cured product of
The fluororesin-coated artificial marble according to claim 1.

[In Formula (1),
R ¹ and R ² are each independently an alkyl group having 1 to 6 carbon atoms, — (CH ₂ ) _m —OOC (CH ₃ ) C═CH ₂ , — (CH ₂ ) _m —OOCCH═CH ₂ or -CH = CH ₂ and m represents 1-6,
Either one or both of R ¹ and R ² is — (CH ₂ ) _m —OOC (CH ₃ ) C═CH ₂ , — (CH ₂ ) _m —OOCCH═CH ₂ or —CH═CH ₂ ;
n represents 1-420] The fluororesin-coated artificial marble according to claim 1 or 2 , wherein the transparent fluororesin coating film has a thickness of 5 to 20 µm. An artificial marble kitchen sink comprising the fluororesin-coated artificial marble according to any one of claims 1 to 3 , wherein the transparent fluororesin coating film is formed on an inner surface of the sink. sink.

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