KR20100017591A - Coated particle with shimmering appearance and engineered stone containing coated particles - Google Patents

Abstract

A coated particle having a shimmering appearance to an observer contains a refractive particle, a transparent coating on the refractive particle, reflective particles and refractive particles embedded in the coating, with one of the reflective particles or the reflective particles primarily at a surface of the coating. Also an engineered stone has a shimmering appearance due to incorporation of coated particles.

Description

COATED PARTICLE WITH SHIMMERING APPEARANCE AND ENGINEERED STONE CONTAINING COATED PARTICLES}

The present invention relates to coated particles having a shimmering appearance and engineered stones which also have a shiny appearance due to the incorporation of the coated particles.

Engineered stone products can be manufactured by well known procedures commercialized by Breton S.p.A. of Castello di Godego, Italy (so-called "Breton Stone"). In this technique, resin precursors are blended with crushed stone aggregates at low weight percentages to provide a relatively dry mass of material, uniformly distributed on a support carrier, vibrated-compacted under vacuum. -compacted) and then cured to produce a rigid product. The process used to implement this technique is disclosed in US Pat. No. 4,698,010 to Tocelli. Breton stone materials are disclosed for use as flooring tiles. Subsequent improvements to this technique, such as US Pat. No. 6,387,985 to Wilkinson and Burchfield, have increased the use of the material for general surface finishes, in particular the kitchen countertops. countertop). Zodiak® Quartz Surfacing from DuPont is an example of a commercially available engineered stone. Whether the product is a floor tile or a kitchen countertop, slabs made by the Breton Stone process require calibration to make the slab flat and to make the thickness uniform, and to reveal the aesthetic characteristics of the product. This is followed by polishing to make the surface glossy.

As described in US Pat. No. 6,387,985, materials for decorative effects may be added. Decorative additives are distinguished from stone fillers primarily by the amount present in the composition. The ground natural stone filler acts as aggregate and is typically present in the range of 85% to 95% by weight. In attempts to increase the visual appeal and aesthetic quality of engineered stones, gemstone gemstones, metal flakes or filings, mica, shells, pearls, colored or transparent polymer particles, specular ( Decorative additives such as mirrored particles and pigments were added. However, their amounts typically did not exceed about 5% by weight, and preferably do not exceed 2% by weight. The decorative additives are thoroughly mixed with the other components during blending or are disposed on the surface after being distributed on the support carrier and prior to vibration- compaction.

However, due to contact with heavy aggregates during the manufacture of the final article, there are factors that limit the incorporation of decorative additives. Such aggregate can act to minimize or impair the desired decorative effect of the additive.

There is a need for additives that impart a decorative appearance that will remain intact during blending and compaction with heavy aggregates. There is also a need for additives that impart new visual appearances.

Summary of the Invention

The present invention relates to coated particles having a shiny appearance to the viewer, wherein the coated particles

(a) refractive particles;

(b) a coating on the refractive particles of (a);

(c) reflective particles embedded in the transparent coating of (b);

(d) refractive index particles embedded in the transparent coating of (b),

The reflective particles of (c) or the refractive particles of (d) are mainly present on the surface of the transparent coating.

The invention also relates to engineered stones containing coated particles.

An important requirement of the present invention is in fact visual, and more particularly this requirement relates to the shiny appearance present in the coated particles. In addition, the shiny appearance is imparted by incorporating the coated particles into the engineered stone.

As used herein, the word "shiny" is used in its usual sense, ie to mean that the light shines in a tremulous or fitful state. "Shaking" is similarly used in its usual sense, i.e. characterized by trembling or tremours.

Transparent particles

The first essential component of the present invention is transparent particles having the ability to refract light. The transparency of the particles can vary, for example translucent particles can be employed, but in contrast opaque particles are not suitable. Glass and transparent quartz are the preferred materials for such particles.

Transparent particles that refract light can vary in size. Particles with a size in the range of 10 mesh to 3 mesh are preferred to be large enough to exhibit a shiny effect while not being too large to allow particles to pass through the manufacturing process without breaking. Larger particles can be used by modifying the process parameters. The surfaces of the transparent particles may be planar, but curved or polyhedral surfaces are more aesthetically interested in that they exhibit a more shiny effect as the viewing angle changes. It should be understood that both larger and smaller particles may be used. In general, however, at least 50%, more preferably 80% of the transparent refractive particles will be present in the range described above in the final product of the engineered stone.

coating

The coating is applied to the transparent refractive particles, which coating is necessary to provide wear resistance. In addition, the coating serves as a binder to retain additional particles, as described more fully below. Preferred coatings typically comprise a polyester containing a coupling agent and a catalyst prior to polymerization. Examples of suitable polyester coatings are described in US Pat. No. 3,278,662 and US Pat. No. 5,321,055. In addition, an acrylic coating may be used as disclosed in US Pat. No. 6,387,985. To effectively coat the transparent refractive particles, the coating prior to polymerization typically has a viscosity in the range of 1000 to 10,000 centipoise, preferably in the range of 4000 to 6000 centipoise.

Polymerization or "curing" of the coating may occur by chemical initiation, heat or UV / visible light, depending on the nature of the polymer from which the coating is formulated, as known to those skilled in the art.

Additives in coatings

In order to obtain a shiny effect on the coated particles, it is necessary to introduce appropriate additives into the coating. At a minimum, the first additive reflects light while the second additive refracts light.

An example of a first additive that reflects light is a metal (eg copper or brass) that also includes an alloy. Further examples include reflective polymers including mica, holographic particles, metallized polyesters, and pearlescent and fluorescent pigments. Examples of the second additive that refracts light are glass and transparent quartz.

The two additives that reflect or refract light will be in the form of particles and will be embedded in the coating. However, the refractive particles will be concentrated near the outer surface of the coating (ie, the surface that is not in contact with the innermost transparent refractive particles to which the coating is applied). The concentration and size of the particles are not critical, provided that both the concentration and size of the particles affect the desired shiny appearance and that the particles need to be embedded in a transparent coating. In general, one of the particles will be evenly distributed in the coating. Examples of such particles are in the range of 1 micrometer to 3 millimeters. Generally, the refractive particles need to be concentrated near the outer surface of the coating and will have a smaller size. Examples of such particle sizes range from 325 mesh to 34 mesh. In a preferred mode, the refractive particles will concentrate on the surface of the coating.

A further beneficial effect is present by the additives concentrated on the surface of the coated particles. Such an advantage is to minimize or eliminate the agglomeration of the coated particles since many are formed simultaneously.

In the above description, it should be understood that individual particles may cause color shifts that are believed to be caused by a combination of refraction and reflection. Such color variations are within the scope of the present invention.

Engineered stone

The aforementioned coating particles are incorporated into the engineered stone to provide a shiny appearance on the stone. Such engineered stones are well known in the art and are characterized as naturally occurring minerals in combination with binders and other additives. Typically, engineered stones contain 85 to 95% by weight of minerals and the remaining binders (based on minerals and binders). Preferred engineered stones contain the foregoing amounts of quartz and a binder such as polyester or acrylic. The binder may be the same binder employed for the coating of the particles. The amount of coated particles to give the glitter effect is not critical, but will be present in an amount of at least 5% by weight of the final composition, for example.

Engineered stones are typically manufactured in slab form. An advantage of the coated particle additive is its ability to withstand the weight and wear present in the manufacture of engineered stones. Such advantages include the ability to be uniformly distributed within the engineered stone, thereby providing a shiny appearance on various surfaces. For example, when engineered stones are used as kitchen countertops, they may exhibit similar appearance on the top surface (ie, the surface that does not face the bottom) and the side surface.

Produce

The coated particles are formed by applying a transparent coating to the reflective particles, wherein both reflective and refractive additives are provided before the coating solidifies. Coated particles are added during the formation of engineered stones (this preparation is well known as described in the background art herein). The coated particles can be mixed into the abrasive mixture and undergo vibration and compaction without losing the coating needed for the shiny effect.

To minimize abrasive contact, the coated particles can be added later in the process. Typically, the addition in this latter step will require placing the coated particles by hand on the surface of the uncured mixture to compact it into the top portion of the mixture. This requires more labor and is not efficient. In addition, the coated particles will mainly be present on the top surface, resulting in an uneven appearance along the edge portion of the engineered stone.

Typically, engineered stone materials are calibrated to remove and polish the surface material for uniformity.

It is to be understood that conventional additives may be added to the coated particles and / or engineered stone compositions.

The following examples are provided to further illustrate the present invention. Unless otherwise indicated, all parts and percentages are by weight.

Example  One

The following materials were used.

¼ × 8 mesh glass (transparent, brown and green)

30 × 50 mesh fine crushed clear glass

Valspar Promoted Quartz Casting Resin with approximately 25% styrene 5766C00012

Luperox 26M50-Peroxide

Silquest A-174-Coupling Agent

Silverline Silver Holograhic Flake GP 188SV

100 grams of resin was poured into a plastic container. Both 1 gram of Ruperox 26M50 and Silquest A-174 were added to the resin and stirred until well mixed. To this mixture, 5 grams of Silverline Silver Holographic Flake GP 188 SV was added and stirred until thoroughly mixed.

Various colors of ¼ × 8 mesh glass (clear, brown, or green) were placed into 113.4 gram (4 ounce) sample cups. These cups were filled with glass up to approximately 1/3 to ½. A small amount of resin mixture was added and stirred using a plastic stir bar, then additional resin was added and stirred until all the glass in the cup was uniformly coated with the resin mixture (approximately 12-14 weight percent of the binder resin). I was. The resin coated glass particles were then transferred to a large strainer, causing any excess resin mixture to fall from the glass. The resin coated glass particles were then transferred to a pail filled with 30 × 50 mesh fine crushed clear glass. Using protective gloves with neoprene on the outside, the resin coated glass particles were stirred in 30 × 50 mesh fine crushed clear glass. This process was repeated to obtain resin coated particles of desired quality with an additional coating of 30 × 50 mesh fine crushed clear glass. A sieve was used to remove any excess 30 × 50 mesh fine crushed clear glass.

The resin and glass coated particles were evenly spread on a baking sheet and placed in an oven to cure the resin for 45 minutes at a temperature of 120 degrees Celsius. Once cured, any remaining fallen fine transparent ground glass was separated. The coated particles were placed in a bag and labeled. The particles were then used in the engineered stone slab manufacturing process as follows;

material

1.466 kg Titanium Dioxide (TiO ₂ ) Pigment

0.070 kg peroxide catalyst

6.400 kg Balsper Resin

0.104 kg Silquest A-174 Silane Coupling Agent

04.550 kg coated particle additive

13.410 kg 10 mesh quartz aggregate

21.556 kg 34 Mesh Quartz Aggregate

7.900 kg 84 mesh quartz aggregate

18.45 kg 325 mesh quartz aggregate

The material was placed in a mixer and blended for 215 seconds. These were transferred to a lay-down frame and distributed onto a support carrier. The support carrier in which the mixture was distributed was transferred into a vibration compactor and the material was compacted. After vibration- compaction, the material was transferred into an oven and cured to form a slab of engineered stone. Engineered stone slabs were polished to the final article with the desired decorative effect.

Example 2

The following materials were used.

3/8 × ¼ mesh clear glass

Silverbond 325 Mesh Powder

84 mesh quartz

Balsper Promoted Quartz Casting Resin with 19% Styrene 5766C00012

Luperox 26M50 Peroxide

Silquest A-174 Coupling Agent

Sparkle Silvex 755-20-C Aluminum Pigment

Afflair 600 Biotite Pigment

126 grams of resin were poured into a plastic container and both 2.5 grams of Luperox 26M50 and Silquest A-174 were added to the resin and stirred until mixed. To this mixture, 6.5 grams of Sparkle Silbex 755-20-C aluminum pigment and 3.1 grams of Affliction 600 biotite pigment were added and stirred until thoroughly mixed.

500 grams of 3/8 × ¼ mesh clear glass was charged into a stainless steel bowl. A small amount of resin mixture was added and stirred using a plastic stir bar. The resin mixture was added and stirred until all the glass in the cup was uniformly coated with the resin mixture. The coated glass particles were then transferred to a pail filled with silverbond 325 mesh powder and 84 mesh quartz. The coated glass particles were stirred in fines until coated. The process was repeated until there was a large amount of coated particles in the fines. Once sufficient coated particles were present, the fines were poured through a sieve to separate the fines from the coated glass particles. The coated glass particles were evenly spread on the baking sheet and placed in an oven. Alternatively, some particles were left in the particle fines to cure. The coated particles were cured for 45 minutes at 120 degrees Celsius. Once cured, any remaining fallen fines were separated from the coated particles. The coated particles were placed in a bag and labeled.

The particles were then used in the engineered stone slab manufacturing process as follows;

material

0.009 kg Bayer Black 318M Pigment

0.180 kg Sparkle Silbex 755-20-C Pigment

0.058 kg peroxide catalyst

2.890 kg Balsper resin

0.043 kg Silquest A-174 Silane Coupling Agent

5.680 kg coated particle additive

8.285 kg 10 mesh quartz aggregate

6.917 kg 34 mesh quartz aggregate

2.605 kg 84 mesh quartz aggregate

8.155 kg 325 mesh quartz aggregate

The material was placed in a mixer and blended for 215 seconds. They were transferred to a laydown frame and distributed onto a support carrier. The support carrier in which the mixture was distributed was transferred into a vibration compactor and the material was compacted. After vibration- compaction, the material was transferred into an oven and cured to form a slab of engineered stone. Engineered stone slabs were polished to the final article with the desired decorative effect.

Claims (12)

Coated particles with a shiny appearance to the viewer, (a) refractive particles; (b) a transparent coating on the refractive particles of (a); (c) reflective particles embedded in the coating of (b); (d) comprises refractive particles embedded in the coating of (b), Coated particles wherein the reflective particles of (c) or the refractive particles of (d) are mainly present on the surface of the coating. The coated particle of claim 1, wherein the refractive particles of (a) have a size in the range of 10 mesh to 3 mesh. The method of claim 1, The refractive particles of (d) are mainly coated particles present on the outer surface of the coating. The coated particle of claim 3, wherein the refractive particle of (d) has a size ranging from 325 mesh to 34 mesh. The coated particle of claim 1, wherein at least a portion of the reflective particle of (c) has a size ranging from 1 micrometer to 3 millimeters. The coated particle of claim 1, wherein the refractive particle of (a) is glass. The method of claim 1, The transparent coating of (b) is coated particles comprising a polyester containing polymer. The method of claim 1, The transparent coating of (b) is coated particles comprising an acrylic containing polymer. The coated particle of claim 1, wherein the reflective particle of (c) is a metal. The coated particle of claim 1, wherein the refractive particle of (d) is glass. The method of claim 1, Coated particles wherein (a) is glass, (b) comprises a polyester-containing polymer, (c) is a metal, and (d) is glass. An engineered stone sheet having a shiny appearance to an observer and containing naturally occurring minerals and binders in the form of particles, The sheet further contains a plurality of coated particles, each of the coated particles, (a) refractive particles; (b) a coating on the refractive particles of (a); (c) reflective particles embedded in the coating of (b); (d) comprises refractive particles embedded in the coating of (b), An engineered stone sheet wherein the reflective particles of (c) or the refractive particles of (d) are mainly present on the surface of the coating.