JP3565130B2 - Manufacturing method of artificial marble - Google Patents

Description

【００２７】
ここで、ブチラール樹脂は、ポリビニルアルコールのブチラール反応にて得られるものであるが、完全にブチラール反応を進行させることは理論的にも不可能であり、従って、上記の三種の基本単位からなる構造を有しているものである。
【００２８】
ブチラール樹脂の特性は、ブチラール度、残存アセチル基の量及び原料であるポリビニルアルコールの重合度によって変化するといわれているが、本発明では、これらの形態は特に限定されない。
【００２９】
ブチラール樹脂の添加量は特に限定されるものではないが、熱硬化性樹脂及び必要に応じて配合される架橋剤からなる樹脂成分の総量１００質量部に対して、０．５〜３０質量部の範囲とすることが好ましい。この添加量が０．５質量部に満たないと、人造大理石の耐衝撃強度を充分に向上することが困難となる。一方、この添加量が３０質量部を超えると、樹脂組成物の粘度が急激に増大して、成形性が悪化したり、熱可塑性成分であるブチラール樹脂の配合量が大きくなることにより人造大理石の耐熱性が低下したりするおそれがある。
【００３０】
硬化剤としては、１，１，３，３−テトラメチルブチルパーオキシ−２−エチルヘキサエートや、ｔ−ヘキシルパーオキシ−２−エチルヘキサノエート等を用いることができる。この硬化剤の配合割合は、例えば熱硬化性樹脂としてビニルエステル樹脂を用いている場合は、熱硬化性樹脂及び必要に応じて配合される架橋剤からなる樹脂成分の総量１００質量部に対して、０．５〜５質量部とすることが好ましい。
【００３１】
また、充填材としてはシリカ、炭酸カルシウム、水酸化アルミニウム、ガラスパウダー、クレー等を用いることができ、これらを一種のみ用い、あるいは二種以上を併用することができる。
【００３２】
このような充填材の配合量は、熱硬化性樹脂及び必要に応じて配合される架橋剤からなる樹脂成分の総量１００質量部に対して、１８０〜３００質量部とすることが好ましい。配合量がこの範囲に満たないと、得られる人造大理石の耐衝撃強度は向上することができるが、充分な耐熱性が得られないおそれがあり、またこの範囲を超えると充分な耐熱性は得られるものの、耐衝撃強度を充分に向上することができなくなるおそれがある。
【００３３】
また、充填材全体の平均粒径が、５０μｍ以下のものを用いることが好ましく、この場合、人造大理石の靱性を向上して耐衝撃強度を効果的に向上することができる。一方、充填材全体の平均粒径が小さすぎると、樹脂組成物中における充填材の分散性が低下して充填材の凝集が生じるおそれがあるため、充填材の平均粒径の下限は３μｍとすることが好ましい。
【００３４】
また充填材の表面に予めシランカップリング剤処理を施しておくと、樹脂組成物中において充填材と樹脂成分との密着性を向上することができ、更に充填材の分散性も向上することができて、得られる人造大理石の耐衝撃強度を更に向上することができるものである。シランカップリング剤としては、γ−（メタクリロイルオキシプロピル）トリメトキシシラン等を用いることができる。
【００３５】
また、樹脂組成物には必要に応じて、紫外線吸収剤、減粘剤、離型剤、ガラス繊維、着色剤等を配合することもできる。
【００３６】
減粘剤としては例えばＢＫＹ製の品番「Ｗ９９６」を、離型剤としては例えば中京油脂製の商品名「セパール」を、ガラス繊維としては例えば日本板硝子製の品番「ＲＥＳ０３Ｘ−ＢＭ」を用いることができる。
【００３７】
また紫外線吸収剤としてはベンゾトリアゾール系、トリアジン系、ベンゾエート系、サリレート系、シアノアクリレート系、シュウ酸アニリド系、ベンゾフェノン系等のものを使用することができる。
【００３８】
樹脂組成物は、樹脂成分に充填材を配合し、更に硬化剤及びその他の各種の添加剤を所定の割合で配合し、攪拌機等により撹拌混合することによって調製される。
【００３９】
ここで、ブチラール樹脂は、予めブチラール樹脂を溶剤や樹脂中に溶解又は分散させた後に、樹脂組成物中に配合する。溶媒としてはスチレンを用いる。このようにして、粉状の樹脂であるブチラール樹脂を一旦溶媒や樹脂中に溶解又は分散させてから樹脂組成物中に配合することにより、樹脂組成物中におけるブチラール樹脂の分散性を向上することができ、ブチラール樹脂を添加することによる耐衝撃強度の向上の効果を、製造される人造大理石の全領域に亘って均質に得ることができるものである。
【００４０】
ここで、ブチラール樹脂をスチレンに溶解させた後に配合する場合は、予め調製されたブチラール樹脂のスチレン溶液中におけるブチラール樹脂の濃度が、１０〜１５質量％の範囲となるようにすると、スチレン中においてブチラール樹脂が良好に溶解・分散し、樹脂組成物中に配合する場合もブチラール樹脂を樹脂組成物中に良好に分散させることができるものである。スチレン溶液中のブチラール樹脂の濃度がこの範囲を超えると、ブチラール樹脂をスチレン中に完全に溶解させることが困難となり、逆にブチラール樹脂の濃度がこの範囲に満たないと、樹脂組成物中におけるスチレンの配合量が多くなりすぎる。
【００４１】
樹脂組成物から人造大理石を製造するにあたっては、まず樹脂組成物を４．０〜６６．５ｈＰａ（３〜５０Ｔｏｒｒ）の減圧下で５〜３０分間攪拌することにより脱泡する。このようにして脱泡された樹脂組成物を、減圧状態から開圧し、所定の金型内へ注入して、この金型を５０〜１１０℃の温度で３０〜１２０分間加熱することにより、樹脂組成物中の熱硬化性樹脂の重合反応を進行させて、硬化成形を行う。
【００４２】
このようにして製造される人造大理石は、優れた耐衝撃強度を有することとなり、人造大理石の裏面に木製の補強板やＦＲＰ補強層等を形成して強度を補うような必要がなく、高い耐衝撃性（靱性）を発揮することができる。更にこの人造大理石にて形成される製品の軽量化を図ると共に、外観、特に透明性に優れた人造大理石を得ることができるものである。
【００４３】
この人造大理石は例えば板状に成形してキッチンカウンターの天板等に使用することができる。
【００４４】
【実施例】
以下、本発明を実施例によって詳述する。
【００４５】
（実施例１）
樹脂成分としては、ビニルエステル樹脂（武田薬品工業株式会社製；商品名「プロミネートＰ−３１１」）を用いた。
【００４６】
ブチラール樹脂（電気化学工業株式会社製；商品名「デンカブチラール＃３０００Ｋ」）は、上記樹脂成分１００質量部に対して３．０質量部用い、樹脂組成物中に配合する前に予めスチレン中に１０質量％の濃度で溶解させた。
【００４７】
充填材としては、水酸化アルミニウム（住友化学工業株式会社製；品番「ＣＷ−３０８Ｂ」）を、樹脂成分１００質量部に対し、２００質量部用いた。
【００４８】
硬化剤としては、１，１，３，３−テトラメチルブチルパーオキシ−２−エチルヘキサノエート（日本油脂株式会社製；商品名「パーキュアＷＯ」）を適量用いた。
【００４９】
これらの各成分を配合し、攪拌機により撹拌混合して樹脂組成物を調製した。
【００５０】
この樹脂組成物を、２６．７ｈＰａ（２０Ｔｏｒｒ）の減圧下で、３０分間真空脱泡処理した。更にこの樹脂組成物を、厚み１１ｍｍの平板が成形できるキャビティを備える金型内に注入し、金型温度９０℃で７０分間加熱して、平板状の人造大理石を成形した。
【００５１】
（実施例２）
樹脂成分として、アクリルシロップ樹脂（日本フェロー株式会社製；商品名「ＡＣ−０２」）を用いた。
【００５２】
ブチラール樹脂（電気化学工業株式会社製；商品名「デンカブチラール＃４０００−１」）は、上記樹脂成分１００質量部に対して６．０質量部用い、樹脂組成物中に配合する前に予めスチレン中に１５質量％の濃度で溶解させた。
【００５３】
充填材としては、シリカ（龍森株式会社製；品番「ＣＲＹＳＴＡＬＩＴＥ ２１０５−３０」）を、樹脂成分１００質量部に対して１９０質量部用いた。
【００５４】
硬化剤としては、化薬アクゾ株式会社製の商品名「パーカドックス１６」を適量用いた。
【００５５】
これらの各成分を配合し、攪拌機により撹拌混合して樹脂組成物を調製した。
【００５６】
この樹脂組成物を、２６．７ｈＰａの減圧下で、３０分間真空脱泡処理した。更にこの樹脂組成物を、厚み１１ｍｍの平板が成形できるキャビティを備える金型内に注入し、金型温度９０℃で５０分間加熱して、平板状の人造大理石を成形した。
【００５７】
（実施例３）
樹脂成分として、ポリエステル樹脂（武田薬品工業株式会社製；商品名「ポリマール５４５０」）を用いた。
【００５８】
ブチラール樹脂（電気化学工業株式会社製；商品名「デンカブチラール＃３０００−１」）は、上記樹脂成分１００質量部に対して６．０質量部用い、樹脂組成物中に配合する前に予めスチレン中に１５質量％の濃度で溶解させた。
【００５９】
充填材としては、水酸化アルミニウム（昭和電工株式会社製；品番「Ｈ−３１０」）を、樹脂成分１００質量部に対して２１０質量部用いた。
【００６０】
硬化剤としては、ｔ−ヘキシルパーオキシ２−エチルヘキサノエート（日本油脂株式会社製；商品名「パーキュアＨＯ」）を、適量用いた。
【００６１】
これらの各成分を配合し、攪拌機により撹拌混合して樹脂組成物を調製した。
【００６２】
この樹脂組成物を、２６．７ｈＰａの減圧下で、３０分間真空脱泡処理した。更にこの樹脂組成物を、厚み１１ｍｍの平板が成形できるキャビティを備える金型内に注入し、金型温度９０℃で８０分間加熱して、平板状の人造大理石を成形した。
【００６３】
（実施例４）
樹脂成分として、ビニルエステル樹脂（昭和高分子株式会社製；商品名「リポキシＲ−８０４」）５０質量部と、ポリエステル樹脂（武田薬品工業株式会社製；商品名「ポリマール５２５０」）５０質量部とを混合したものを用いた。
【００６４】
ブチラール樹脂（電気化学工業株式会社製；商品名「デンカブチラール＃６０００−Ｃ」）は、上記樹脂成分１００質量部に対して４．０質量部用い、樹脂組成物中に配合する前に予めスチレン中に１５質量％の濃度で溶解させた。
【００６５】
充填材としては、水酸化アルミニウム（昭和電工株式会社製；品番「Ｈ−３２０」）を、樹脂成分１００質量部に対して２１０質量部用いた。
【００６６】
硬化剤としては、ｔ−ヘキシルパーオキシ２−エチルヘキサノエート（日本油脂株式会社製；商品名「パーキュアＨＯ」）を適量用いた。
【００６７】
これらの各成分を配合し、攪拌機により撹拌混合して樹脂組成物を調製した。
【００６８】
この樹脂組成物を、２６．７ｈＰａの減圧下で、３０分間真空脱泡処理した。更にこの樹脂組成物を、厚み１１ｍｍの平板が成形できるキャビティを備える金型内に注入し、金型温度９０℃で８０分間加熱して、平板状の人造大理石を成形した。
【００６９】
（実施例５）
樹脂成分として、ビニルエステル樹脂（昭和高分子株式会社製；商品名「リポキシＲ−８０６」）６５質量部と、アクリルシロップ樹脂（三井化学株式会社製；商品名「ＸＥ９２４−１」）３５質量部とを混合したものを用いた。
【００７０】
ブチラール樹脂（電気化学工業株式会社製；商品名「デンカブチラール＃３０００−Ｋ」）は、上記樹脂成分１００質量部に対して８．０質量部用い、樹脂組成物中に配合する前に予めスチレン中に１５質量％の濃度で溶解させた。
【００７１】
充填材としては、水酸化アルミニウム（昭和電工株式会社製；品番「Ｈ−３２０」）を、樹脂成分１００質量部に対して２００質量部用いた。
【００７２】
硬化剤としては、１，１，３，３−テトラメチルブチルパーオキシ−２−エチルヘキサノエート（日本油脂株式会社製；商品名「パーキュアＷＯ」）を適量用いた。
【００７３】
これらの各成分を配合し、攪拌機により撹拌混合して樹脂組成物を調製した。
【００７４】
この樹脂組成物を、２６．７ｈＰａの減圧下で、３０分間真空脱泡処理した。更にこの樹脂組成物を、厚み１１ｍｍの平板が成形できるキャビティを備える金型内に注入し、金型温度９０℃で８０分間加熱して、平板状の人造大理石を成形した。
【００７５】
（実施例６）
樹脂成分として、ビニルエステル樹脂（武田薬品工業株式会社製；商品名「プロミネートＰ−３１０」）６０質量部と、アクリルシロップ樹脂（三井化学株式会社製；商品名「ＸＥ９２４−１」）１０質量部と、ポリエステル樹脂（武田薬品工業株式会社製；商品名「ポリマール５２５０」）３０質量部とを混合したものを用いた。
【００７６】
ブチラール樹脂（電気化学工業株式会社製；商品名「デンカブチラール＃３０００−２」）は、上記樹脂成分１００質量部に対して７．５質量部用い、樹脂組成物中に配合する前に予めスチレン中に１５質量％の濃度で溶解させた。
【００７７】
充填材としては、水酸化アルミニウム（住友化学工業株式会社製；品番「ＣＷ−３２５ＬＶ」）８０質量部とシリカ（白石工業株式会社製；品番「ＭＩＬＬＩＳＩＬ Ｍ１０」）２０質量部とを混合したものを、樹脂成分１００質量部に対して２００質量部用いた。
【００７８】
硬化剤としては、１，１，３，３−テトラメチルブチルパーオキシ−２−エチルヘキサノエート（日本油脂株式会社製；商品名「パーキュアＷＯ」）を適量用いた。
【００７９】
これらの各成分を配合し、攪拌機により撹拌混合して樹脂組成物を調製した。
【００８０】
この樹脂組成物を、２６．７ｈＰａの減圧下で、３０分間真空脱泡処理した。更にこの樹脂組成物を、厚み１１ｍｍの平板が成形できるキャビティを備える金型内に注入し、金型温度９０℃で８０分間加熱して、平板状の人造大理石を成形した。
【００８１】
（比較例１〜６）
ブチラール樹脂を配合しなかった以外は、各実施例と同様にして、板状の人造大理石を得た。
【００８２】
（評価試験）
以上の各実施例及び各比較例にて得られた人造大理石につき、シャルピー衝撃強度を測定した。またこの各人造大理石の外観を目視にて観察して、透明性を評価した。この結果を表１に示す。
【００８３】
【表１】

【００８４】
【発明の効果】
上記のように本発明の請求項１に係る人造大理石の製造方法は、熱硬化性樹脂からなる樹脂成分と充填材とを含有する樹脂組成物を成形硬化させて得られる人造大理石の製造方法において、ブチラール樹脂を含有する樹脂組成物を用いるため、優れた耐衝撃強度を有する人造大理石を製造することができ、人造大理石の裏面に木製の補強板やＦＲＰ補強層等を形成して強度を補うような必要がなく、高い耐衝撃性を発揮することができるものであり、この人造大理石にて形成される製品の軽量化を図ると共に、外観、特に透明性を向上することができるものである。また、ブチラール樹脂をスチレンに溶解させた後に、樹脂組成物中に配合するため、粉状のブチラール樹脂を一旦スチレン中に溶解・分散させた後に更に樹脂組成物中に配合することとなって、樹脂組成物中のブチラール樹脂の分散性が向上し、製造される人造大理石の全領域に亘って均質に耐衝撃強度を向上することができるものである。
【００８５】
また請求項２に記載の発明は、請求項１の構成に加えて、ブチラール樹脂を、樹脂成分１００質量部に対して０．５〜３０質量部配合するため、更に優れた耐衝撃強度を有する人造大理石を製造することができ、人造大理石の裏面に木製の補強板やＦＲＰ補強層等を形成して強度を補うような必要がなく、高い耐衝撃性を発揮することができるものであり、この人造大理石にて形成される製品の軽量化を図ると共に、外観、特に透明性を向上することができるものである。
【００８７】
また請求項３に記載の発明は、請求項１又は２の構成に加えて、ブチラール樹脂を、１０〜１５質量％の濃度範囲でスチレンに溶解させた後に、樹脂組成物中に配合するため、スチレン中にブチラール樹脂を良好に溶解・分散させた後に樹脂組成物中に配合することとなって、樹脂組成物中のブチラール樹脂の分散性が更に向上し、製造される人造大理石の全領域に亘って更に均質に耐衝撃強度を向上することができるものである。
【００８８】
また請求項４に記載の発明は、請求項１乃至３のいずれかの構成に加えて、熱硬化性樹脂として、ビニルエステル樹脂、アクリル樹脂、ポリエステル樹脂のうちの、少なくとも一種のものを用いるため、それぞれの樹脂の有する特性に応じて配合割合を調整することにより、目的とする製品に適した物性を有する人造大理石を得ることができるものである。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing artificial marble used as a member of furniture or a building material.
[0002]
[Prior art]
Conventionally, artificial marble is prepared by injecting a resin composition in which a resin, a filler, a reinforcing material, an internal release agent, an additive such as a curing agent, and the like are blended into a casting mold having a desired shape, and curing by heating. Was known to form.
[0003]
As a resin as a raw material for producing such artificial marble, a polyester-based resin, an acrylic-based resin, a vinyl ester-based resin, or the like has been conventionally used.
[0004]
Artificial marble molded products utilizing these are used for wash counters, kitchen counters, bathtubs, wash bowls and the like.
[0005]
Usually, in order to improve the impact resistance (toughness) of artificial marble, the amount of glass fiber as a reinforcing material is increased. However, when the blending amount of the glass fiber is increased, the flow of the pattern or pattern formed on the artificial marble is significantly inhibited, the mixing and dispersibility becomes uneven, the transparency of the product is reduced, and the product surface is deteriorated. In addition, a uniform product cannot be obtained, for example, due to fluffing of the glass fiber, and there is a limit in improving the product strength.
[0006]
Therefore, in order to solve such a problem, the thickness of the product is increased by providing a wooden reinforcing plate on the back surface of the artificial marble or providing a reinforcing layer of FRP (fiber reinforced plastic). I was
[0007]
[Problems to be solved by the invention]
However, in order to reinforce the back surface of the artificial marble as described above, it takes time and effort to process and leads to an increase in cost. In addition, since the thickness of the reinforcing plate or the like is added to the product, it is difficult to reduce the thickness of the product, and accordingly, the weight of the product increases, and the burden on the transportation and construction of the product increases. In addition, the provision of a reinforcing plate or the like impairs the transparency of the product and deteriorates the appearance.
[0008]
The present invention has been made in view of the above points, can improve the impact resistance of artificial marble, eliminates the need to provide a reinforcing plate or the like for a product formed from artificial marble, and reduces the thickness of the product. -It is an object of the present invention to provide a method for producing artificial marble, which can achieve weight reduction and can enhance transparency and improve appearance.
[0009]
[Means for Solving the Problems]
The method for producing artificial marble according to claim 1 of the present invention is directed to a method for producing artificial marble obtained by molding and curing a resin composition containing a resin component composed of a thermosetting resin and a filler. After being dissolved in styrene, it is blended into a resin composition, and a resin composition containing this butyral resin is used.
[0010]
The invention according to claim 2 is characterized in that, in addition to the structure of claim 1, butyral resin is blended in an amount of 0.5 to 30 parts by mass with respect to 100 parts by mass of the resin component.
[0012]
The invention according to claim 3 is characterized in that, in addition to the constitution of claim 1 or 2 , the butyral resin is dissolved in styrene in a concentration range of 10 to 15% by mass and then added to the resin composition. It is a feature.
[0013]
According to a fourth aspect of the present invention, in addition to any one of the first to third aspects, at least one of a vinyl ester resin, an acrylic resin, and a polyester resin is used as the thermosetting resin. It is characterized by the following.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0015]
The resin composition used for the production of artificial marble contains a resin component, a filler, a reinforcing material, an internal release agent, a curing agent, and the like.
[0016]
The resin component is obtained by blending a crosslinking agent with the thermosetting resin as needed. As the thermosetting resin, any one of a vinyl ester resin, an acrylic resin, and a polyester resin is used. More than one species can be used in combination.
[0017]
As the vinyl ester resin, one or both of a bisphenol type vinyl ester resin and a novolak type vinyl ester resin can be used.
[0018]
Here, the bisphenol-type vinyl ester resin is an addition reaction product of a bisphenol-type epoxy resin and an acid, and the novolak-type epoxy resin is an addition reaction product of a novolak-type epoxy resin and an acid. Only have reactive addition reactants.
[0019]
As the bisphenol-type epoxy resin for obtaining the bisphenol-type vinyl ester resin, various types such as bisphenol A-type, bisphenol AD-type, bisphenol S-type and bisphenol F-type can be used.
[0020]
As the acid to be added to the epoxy resin, usually, an unsaturated monobasic acid is used, and acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, sorbic acid, hydroxyethyl methacrylate malate, hydroxyethyl acrylate malate, Hydroxypropyl methacrylate malate, hydroxypropyl acrylate malate, dicyclopentadiene malate and the like can be used.
[0021]
Usually, a styrene monomer, an acrylic monomer, or the like is blended in the vinyl ester resin as a cross-linking agent, but is not particularly limited to such a form.
[0022]
As the acrylic resin, a methyl methacrylate monomer, a polyfunctional acrylic monomer, or a prepolymer thereof, or a thermosetting type usually referred to as an acrylic syrup resin containing two or more of these polymers is usually used. Can be used, but it is not particularly limited to such a form.
[0023]
The polyester resin is synthesized by a condensation reaction of an unsaturated dibasic acid such as maleic anhydride and a saturated dibasic acid such as phthalic anhydride with glycols, and has an unsaturated bond and an ester bond in the molecule. Can be used. Usually, as the polyester resin, an unsaturated polyester resin containing a styrene monomer, an acrylic monomer or the like as a cross-linking agent is used, but it is not particularly limited to such a form.
[0024]
When the thermosetting resin is a mixed type of two or more of a vinyl ester resin, an acrylic resin, and a polyester resin, the properties of each resin, the interaction with the filler, and the butyral resin described later. It is blended at an appropriate ratio suitable for the physical properties of the target product due to interaction or the like, and the blending ratio is not particularly limited.
[0025]
The resin composition contains a butyral resin. This butyral resin is also called polyvinyl butyral or polyvinyl acetal, and has a polyvinyl acetal unit represented by the following structural formula (1), a polyvinyl alcohol unit represented by the following structural formula (2), and a poly (vinyl alcohol) unit represented by the following structural formula (3). It is a resin composed of vinyl acetate units. R in the structural formula (1) represents an arbitrary alkyl group.
[0026]
Embedded image

[0027]
Here, the butyral resin is obtained by the butyral reaction of polyvinyl alcohol, but it is theoretically impossible to allow the butyral reaction to proceed completely.Therefore, the structure comprising the above three kinds of basic units is used. It has.
[0028]
It is said that the properties of the butyral resin vary depending on the degree of butyral, the amount of residual acetyl groups, and the degree of polymerization of the raw material polyvinyl alcohol. However, in the present invention, these forms are not particularly limited.
[0029]
The amount of the butyral resin is not particularly limited, but is preferably 0.5 to 30 parts by mass with respect to 100 parts by mass of the total amount of the thermosetting resin and the resin component composed of the crosslinking agent blended as necessary. It is preferable to set the range. If the amount is less than 0.5 parts by mass, it is difficult to sufficiently improve the impact resistance of artificial marble. On the other hand, when the addition amount exceeds 30 parts by mass, the viscosity of the resin composition sharply increases, moldability deteriorates, or the blending amount of butyral resin as a thermoplastic component increases, so Heat resistance may be reduced.
[0030]
As a curing agent, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, or the like can be used. The mixing ratio of this curing agent is, for example, when a vinyl ester resin is used as the thermosetting resin, based on 100 parts by mass of the total amount of the thermosetting resin and the resin component composed of the cross-linking agent to be mixed as necessary , 0.5 to 5 parts by mass.
[0031]
Further, as the filler, silica, calcium carbonate, aluminum hydroxide, glass powder, clay and the like can be used, and these can be used alone or in combination of two or more.
[0032]
The compounding amount of such a filler is preferably 180 to 300 parts by mass with respect to 100 parts by mass of the total amount of the resin component composed of the thermosetting resin and the crosslinking agent that is optionally compounded. If the compounding amount is less than this range, the impact resistance of the artificial marble obtained can be improved, but sufficient heat resistance may not be obtained, and if it exceeds this range, sufficient heat resistance will be obtained. However, the impact strength may not be sufficiently improved.
[0033]
In addition, it is preferable to use a filler having an average particle diameter of 50 μm or less. In this case, the toughness of the artificial marble can be improved, and the impact resistance can be effectively improved. On the other hand, if the average particle size of the entire filler is too small, the dispersibility of the filler in the resin composition may be reduced and aggregation of the filler may occur. Therefore, the lower limit of the average particle size of the filler is 3 μm. Is preferred.
[0034]
When the surface of the filler is previously treated with a silane coupling agent, the adhesion between the filler and the resin component in the resin composition can be improved, and the dispersibility of the filler can be improved. The impact resistance of the resulting artificial marble can be further improved. As the silane coupling agent, γ- (methacryloyloxypropyl) trimethoxysilane or the like can be used.
[0035]
Further, an ultraviolet absorber, a viscosity reducing agent, a release agent, a glass fiber, a colorant, and the like can be added to the resin composition as needed.
[0036]
For example, BKY product number “W996” is used as a viscosity reducing agent, Chukyo Yushi product name “Separ” is used as a release agent, and Nippon Sheet Glass product number “RES03X-BM” is used as glass fiber. Can be.
[0037]
As the ultraviolet absorber, benzotriazole-based, triazine-based, benzoate-based, salylate-based, cyanoacrylate-based, oxalic anilide-based, and benzophenone-based ones can be used.
[0038]
The resin composition is prepared by blending a filler with a resin component, further blending a curing agent and other various additives at a predetermined ratio, and stirring and mixing with a stirrer or the like.
[0039]
Here, butyral resin, a pre-Me butyral resin was dissolved or dispersed in a solvent or resin, it compounded in the resin composition. The solvent Ru with styrene. In this manner, by dissolving or dispersing the butyral resin which is a powdery resin in a solvent or a resin once and then blending it in the resin composition, the dispersibility of the butyral resin in the resin composition is improved. Thus, the effect of improving the impact resistance by adding the butyral resin can be obtained uniformly over the entire region of the manufactured artificial marble.
[0040]
Here, when the butyral resin is blended after dissolving it in styrene, if the concentration of the butyral resin in the styrene solution of the butyral resin prepared in advance is in the range of 10 to 15% by mass, The butyral resin can be satisfactorily dispersed and dispersed in the resin composition even when the butyral resin is well dissolved and dispersed in the resin composition. If the butyral resin concentration in the styrene solution exceeds this range, it is difficult to completely dissolve the butyral resin in styrene.On the contrary, if the butyral resin concentration is below this range, the styrene in the resin composition Is too large.
[0041]
In producing artificial marble from the resin composition, the resin composition is first defoamed by stirring under reduced pressure of 4.0 to 66.5 hPa (3 to 50 Torr) for 5 to 30 minutes. The resin composition thus defoamed is opened from a reduced pressure state, injected into a predetermined mold, and heated at a temperature of 50 to 110 ° C. for 30 to 120 minutes, whereby the resin Curing molding is performed by advancing the polymerization reaction of the thermosetting resin in the composition.
[0042]
The artificial marble manufactured in this way has an excellent impact resistance, and it is not necessary to form a wooden reinforcing plate or an FRP reinforcing layer on the back surface of the artificial marble to supplement the strength, and has a high resistance to impact. It can exhibit impact properties (toughness). Further, it is possible to reduce the weight of a product formed of the artificial marble and obtain an artificial marble excellent in appearance, particularly transparency.
[0043]
This artificial marble can be formed into, for example, a plate shape and used as a top plate of a kitchen counter or the like.
[0044]
【Example】
Hereinafter, the present invention will be described in detail with reference to examples.
[0045]
(Example 1)
As the resin component, a vinyl ester resin (manufactured by Takeda Pharmaceutical Co., Ltd .; trade name “Prominate P-311”) was used.
[0046]
Butyral resin (manufactured by Denki Kagaku Kogyo Co., Ltd .; trade name “Denka Butyral # 3000K”) was used in an amount of 3.0 parts by mass with respect to 100 parts by mass of the above resin component. It was dissolved at a concentration of 10% by mass.
[0047]
As a filler, 200 parts by mass of aluminum hydroxide (manufactured by Sumitomo Chemical Co., Ltd .; product number “CW-308B”) was used based on 100 parts by mass of the resin component.
[0048]
As a curing agent, an appropriate amount of 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (manufactured by NOF Corporation; trade name “Percure WO”) was used.
[0049]
These components were blended and stirred and mixed by a stirrer to prepare a resin composition.
[0050]
This resin composition was subjected to a vacuum defoaming treatment under a reduced pressure of 26.7 hPa (20 Torr) for 30 minutes. Further, this resin composition was poured into a mold having a cavity capable of molding a flat plate having a thickness of 11 mm, and heated at a mold temperature of 90 ° C. for 70 minutes to form a flat artificial marble.
[0051]
(Example 2)
Acrylic syrup resin (manufactured by Nippon Fellow Co., Ltd .; trade name “AC-02”) was used as a resin component.
[0052]
Butyral resin (manufactured by Denki Kagaku Kogyo Co., Ltd .; trade name “Denka Butyral # 4000-1”) was used in an amount of 6.0 parts by mass with respect to 100 parts by mass of the resin component, and styrene was previously added to the resin composition. In a concentration of 15% by weight.
[0053]
As a filler, 190 parts by mass of silica (manufactured by Tatsumori Corporation; product number “CRYSTALITE 2105-30”) was used with respect to 100 parts by mass of the resin component.
[0054]
As a curing agent, an appropriate amount of trade name “Parcadox 16” manufactured by Kayaku Akzo Co., Ltd. was used.
[0055]
These components were blended and stirred and mixed by a stirrer to prepare a resin composition.
[0056]
This resin composition was subjected to a vacuum defoaming treatment under a reduced pressure of 26.7 hPa for 30 minutes. Further, this resin composition was poured into a mold having a cavity capable of molding a flat plate having a thickness of 11 mm, and heated at a mold temperature of 90 ° C. for 50 minutes to form a flat artificial marble.
[0057]
(Example 3)
As the resin component, a polyester resin (manufactured by Takeda Pharmaceutical Co., Ltd .; trade name “Polymer 5450”) was used.
[0058]
Butyral resin (manufactured by Denki Kagaku Kogyo Co., Ltd .; trade name “Denka Butyral # 3000-1”) was used in an amount of 6.0 parts by mass with respect to 100 parts by mass of the resin component, and styrene was previously added to the resin composition. In a concentration of 15% by weight.
[0059]
As a filler, 210 parts by mass of aluminum hydroxide (manufactured by Showa Denko KK; product number "H-310") was used for 100 parts by mass of the resin component.
[0060]
As a curing agent, an appropriate amount of t-hexyl peroxy 2-ethylhexanoate (manufactured by NOF CORPORATION; trade name "Percure HO") was used.
[0061]
These components were blended and stirred and mixed by a stirrer to prepare a resin composition.
[0062]
This resin composition was subjected to a vacuum defoaming treatment under a reduced pressure of 26.7 hPa for 30 minutes. Further, this resin composition was poured into a mold having a cavity capable of molding a flat plate having a thickness of 11 mm, and heated at a mold temperature of 90 ° C. for 80 minutes to form a flat artificial marble.
[0063]
(Example 4)
As a resin component, 50 parts by mass of a vinyl ester resin (manufactured by Showa Kogyo Co., Ltd .; trade name "Lipoxy R-804") and 50 parts by mass of a polyester resin (manufactured by Takeda Pharmaceutical Co., Ltd .; trade name: "Polymer 5250") Was used.
[0064]
Butyral resin (manufactured by Denki Kagaku Kogyo Co., Ltd .; trade name “Denka Butyral # 6000-C”) was used in an amount of 4.0 parts by mass with respect to 100 parts by mass of the resin component, and styrene was previously added to the resin composition. In a concentration of 15% by weight.
[0065]
As the filler, 210 parts by mass of aluminum hydroxide (manufactured by Showa Denko KK; product number "H-320") was used per 100 parts by mass of the resin component.
[0066]
As a curing agent, an appropriate amount of t-hexyl peroxy 2-ethylhexanoate (manufactured by NOF Corporation; trade name “Percure HO”) was used.
[0067]
These components were blended and stirred and mixed by a stirrer to prepare a resin composition.
[0068]
This resin composition was subjected to a vacuum defoaming treatment under a reduced pressure of 26.7 hPa for 30 minutes. Further, this resin composition was poured into a mold having a cavity capable of molding a flat plate having a thickness of 11 mm, and heated at a mold temperature of 90 ° C. for 80 minutes to form a flat artificial marble.
[0069]
(Example 5)
As resin components, 65 parts by mass of a vinyl ester resin (manufactured by Showa Polymer Co., Ltd .; trade name "Lipoxy R-806") and 35 parts by mass of an acrylic syrup resin (manufactured by Mitsui Chemicals, Inc .; trade name "XE924-1") Was used.
[0070]
Butyral resin (manufactured by Denki Kagaku Kogyo Co., Ltd .; trade name “Denka Butyral # 3000-K”) was used in an amount of 8.0 parts by mass with respect to 100 parts by mass of the resin component, and styrene was previously added to the resin composition. In a concentration of 15% by weight.
[0071]
As the filler, 200 parts by mass of aluminum hydroxide (manufactured by Showa Denko KK; product number "H-320") was used per 100 parts by mass of the resin component.
[0072]
As a curing agent, an appropriate amount of 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (manufactured by NOF Corporation; trade name “Percure WO”) was used.
[0073]
These components were blended and stirred and mixed by a stirrer to prepare a resin composition.
[0074]
This resin composition was subjected to a vacuum defoaming treatment under a reduced pressure of 26.7 hPa for 30 minutes. Further, this resin composition was poured into a mold having a cavity capable of molding a flat plate having a thickness of 11 mm, and heated at a mold temperature of 90 ° C. for 80 minutes to form a flat artificial marble.
[0075]
(Example 6)
As a resin component, 60 parts by mass of a vinyl ester resin (manufactured by Takeda Pharmaceutical Co., Ltd .; trade name “Prominate P-310”) and 10 parts by mass of an acrylic syrup resin (manufactured by Mitsui Chemicals, Inc .; trade name “XE924-1”) And 30 parts by mass of a polyester resin (manufactured by Takeda Pharmaceutical Co., Ltd .; trade name: “Polymer 5250”) were used.
[0076]
Butyral resin (manufactured by Denki Kagaku Kogyo Co., Ltd .; trade name "Denka Butyral # 3000-2") was used in an amount of 7.5 parts by mass with respect to 100 parts by mass of the above resin component, and styrene was previously added to the resin composition. In a concentration of 15% by weight.
[0077]
As the filler, a mixture of 80 parts by mass of aluminum hydroxide (manufactured by Sumitomo Chemical Co., Ltd .; product number "CW-325LV") and 20 parts by mass of silica (manufactured by Shiraishi Industry Co., Ltd .; product number "MILLISIL M10") is used. And 200 parts by mass with respect to 100 parts by mass of the resin component.
[0078]
As a curing agent, an appropriate amount of 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (manufactured by NOF Corporation; trade name “Percure WO”) was used.
[0079]
These components were blended and stirred and mixed by a stirrer to prepare a resin composition.
[0080]
This resin composition was subjected to a vacuum defoaming treatment under a reduced pressure of 26.7 hPa for 30 minutes. Further, this resin composition was poured into a mold having a cavity capable of molding a flat plate having a thickness of 11 mm, and heated at a mold temperature of 90 ° C. for 80 minutes to form a flat artificial marble.
[0081]
(Comparative Examples 1 to 6)
A plate-like artificial marble was obtained in the same manner as in each example except that the butyral resin was not blended.
[0082]
(Evaluation test)
The Charpy impact strength of the artificial marble obtained in each of the above Examples and Comparative Examples was measured. The appearance of each artificial marble was visually observed to evaluate the transparency. Table 1 shows the results.
[0083]
[Table 1]

[0084]
【The invention's effect】
As described above, the method for producing artificial marble according to claim 1 of the present invention relates to a method for producing artificial marble obtained by molding and curing a resin composition containing a resin component composed of a thermosetting resin and a filler. Since the resin composition containing butyral resin is used, artificial marble having excellent impact strength can be manufactured, and a wooden reinforcing plate or an FRP reinforcing layer is formed on the back surface of the artificial marble to supplement the strength. It is possible to exhibit high impact resistance without such necessity, and it is possible to reduce the weight of a product formed of this artificial marble and to improve the appearance, particularly transparency. . Also, after dissolving the butyral resin in styrene, to be blended into the resin composition, the powdery butyral resin will be further dissolved and dispersed in styrene and then further blended into the resin composition, The dispersibility of the butyral resin in the resin composition is improved, and the impact resistance can be uniformly improved over the entire region of the manufactured artificial marble.
[0085]
The invention according to claim 2 has, in addition to the structure of claim 1, a butyral resin in an amount of 0.5 to 30 parts by mass with respect to 100 parts by mass of the resin component, so that the impact resistance is more excellent. Artificial marble can be manufactured, and there is no need to supplement the strength by forming a wooden reinforcing plate or FRP reinforcing layer on the back of the artificial marble, and it can exhibit high impact resistance. It is possible to reduce the weight of the product formed of the artificial marble and to improve the appearance, particularly the transparency.
[0087]
Further, in the invention according to claim 3 , in addition to the constitution of claim 1 or 2 , the butyral resin is dissolved in styrene in a concentration range of 10 to 15% by mass and then added to the resin composition. After dissolving and dispersing the butyral resin in styrene well, it is blended into the resin composition, and the dispersibility of the butyral resin in the resin composition is further improved. The impact resistance can be more uniformly improved over the entire area.
[0088]
According to a fourth aspect of the present invention, in addition to any one of the first to third aspects, at least one of a vinyl ester resin, an acrylic resin, and a polyester resin is used as the thermosetting resin. By adjusting the mixing ratio in accordance with the properties of each resin, artificial marble having physical properties suitable for a target product can be obtained.

Claims (4)

In a method for producing artificial marble obtained by molding and curing a resin composition containing a resin component composed of a thermosetting resin and a filler, a butyral resin is dissolved in styrene and then blended into the resin composition. A method for producing artificial marble, comprising using a resin composition containing a butyral resin. The method for producing artificial marble according to claim 1, wherein the butyral resin is mixed in an amount of 0.5 to 30 parts by mass with respect to 100 parts by mass of the resin component. The method for producing artificial marble according to claim 1 or 2, wherein the butyral resin is dissolved in styrene in a concentration range of 10 to 15% by mass and then added to the resin composition. The method for producing artificial marble according to any one of claims 1 to 3, wherein at least one of a vinyl ester resin, an acrylic resin, and a polyester resin is used as the thermosetting resin .