Field of the Invention

The present invention relates to a composition for composite solid surface article which contains ocher or loess. More particularly, the present invention relates to an eco-friendly composition for composite solid surface article having unique ocher texture by employing specific size in specific amount of loess powder to an acrylic resin.

Background of the Invention

An artificial marble has been widely used as a building material. The artificial marble is classified into two groups according to a base resin material: one is acrylic artificial marble, and the other is unsaturated polyester artificial marble. Recently, the acrylic artificial marble is widely used for its excellent appearance, high-class texture and good weatherability compared with the unsaturated polyester artificial marble. For examples, the acrylic artificial marble is used as a material for kitchen top boards, wash bowls, dressing tables, bathtubs, various count tables, wall materials, interior articles, etc.

However, conventional artificial marbles have been focused on realizing natural-stone-like texture, so conventional marbles do not go beyond stone-like patterns and are not eco-friendly material.

In general, ocher or loess has excellent detoxificant and antibacterial effects. So it has been widely used in food, cosmetic materials, cloth, etc. Because it is a trend to use loess, any product containing loess is popular.

Further, ocher or loess has a capability of controlling temperature and humidity. So, it acts as an insulator and provides coolness in the summer and

warmth in the winter. It has also been used as traditional building materials in Korea.

Therefore, the artificial marble which employs loess would be especially suitable for use in interior building materials or various interior articles. However, such materials or articles having both good mechanical strength and elegant ocher texture have not been developed due to the low compatibility between loess or ocher and acrylic matrix resin and their poor process stability.

Korean Patent No. 272421 discloses a method of preparing artificial marble comprising preparing a loess molding layer consisting of a mixture of loess and unsaturated polyester resin, laminating a zeolite surface layer consisting of a mixture of zeolite and unsaturated polyester resin onto the molding layer, and curing the laminated layers. However, this method shows poor process stability and the resulting artificial marbles prepared therefrom have poor mechanical strength due to the high content of loess.

Accordingly, the present inventors have developed an eco-friendly composite solid surface article having good mechanical strength and unique ocher texture by adding specific size in specific amount of loess to an acrylic artificial composition.

Objects of the Invention

An object of the present invention is to provide a composition for composite solid surface article having peculiar ocher texture.

Another object of the present invention is to provide an eco-friendly composition for composite solid surface article. A further object of the present invention is to provide a composition for composite solid surface article having good mechanical strength.

Other objects and advantages of this invention will be apparent from the ensuing disclosure and appended claims.

Summary of the Invention

One aspect of the invention provides a composite solid surface article, comprising (a) about 100 parts by weight of an acrylic resin; (b) about 1 to 30 parts by weight of ocher or loess powder having a particle size of about 1 to 50 μm; (c) about 100 to 200 parts by weight of an inorganic filler; (d) about 0.1 to 10 parts by weight of a cross-linking agent; and (e) about 0.1 to 10 parts by weight of a polymerization initiator. In some embodiments the composite solid surface article may also comprise about 0.1 to 150 parts by weight of marble chips.

Brief Description of the Drawings

FIG. 1 is a photograph showing a surface pattern of composite solid surface article obtained in Example 1.

Detailed Description of the Invention

The composite solid surface article comprises (a) about 100 parts by weight of an acrylic resin; (b) about 1 to 30 parts by weight of ocher or loess powder having a particle size of about 1 to 50 μm; (c) about 100 to 200 parts by weight of an inorganic filler; (d) about 0.1 to 10 parts by weight of a cross-linking agent; and (e) about 0.1 to 10 parts by weight of a polymerization initiator.

(a) Acrylic Resin

The acrylic resin used in the present invention is resin syrup comprising a mixture of acrylic monomer and its polymer, polyacrylate.

Typical examples of the acrylic monomer include methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, and so forth.

In one embodiment, the acrylic monomer is equal to or more than 65 % by weight and the polyacrylate is equal to or less than 35 % by weight based on total acrylic resin syrup.

(b) Ocher or loess Powder

In embodiments, the loess powder has an average particle size of about 1 to 50 μm. It is preferable that the loess powder has an average particle size of about 5 to 4OiMn, considering even higher mechanical properties. If the loess powder having a particle size of less than 1 /m is used, it is difficult to control the process. If the loess powder having a particle size of more than 50 μm is used, the mechanical strength of the composite solid surface article tends to be lowered.

According to embodiments, the composite solid surface article is eco- friendly and may have peculiar ocher texture by using the loess powder.

The content of the loess powder is in the range from about 1 to about 30 parts by weight, preferably about 5 to about 25 parts by weight, per 100 parts by weight of acrylic resin.

If the content is more than 30 parts by weight, there may be a problem that the mechanical strength of the composite solid surface article can be deteriorated. On the other hand, if the content is less than 1 part by weight, the composite solid surface article prepared therefrom may not obtain a unique loessial pattern.

(c) Inorganic Filler

As the inorganic filler, any inorganic filler well known in the art can be used. Typical examples of the inorganic filler include calcium carbonate, aluminium hydroxide, silica, alumina, barium sulfate, magnesium hydroxide, etc. Preferably, the inorganic filler of the present invention may have a particle size of about 1 to 100 μm.

Among them, aluminium hydroxide is most preferable in view of the transparent and elegant appearance of artificial marble to be obtained.

The content of the inorganic filler may be in the range from about 100 to about 200 parts by weight, preferably from about 120 to about 160 parts by weight, per 100 parts by weight of acrylic resin.

(d) Cross-Linking Agent

As the cross-linking agent, polyfunctional (meth)acrylate can be used. Examples of the polyfunctional (meth)acrylate include ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, glycerol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, bisphenol A di(meth)acrylate, etc.

The content of the cross-linking agent may be in the range from about 0.1 to 10 parts by weight, preferably from about 0.3 to 10 parts by weight, per 100 parts by weight of acrylic resin.

(e) Polymerization Initiator

Examples of the polymerization initiator may include peroxides such as benzoyl peroxide, lauroyl peroxide, butyl hydroperoxide, cumene hydroperoxide, etc, and azo compound such as azobisisobutylonitrile and the like.

The content of the polymerization initiator may be in the range from about 0.1 to 10 parts by weight, per 100 parts by weight of acrylic resin.

(f) Marble Chips

In some embodiments, conventional artificial marble chips with various colors may be optionally added. Typically, such marble chips may have particle sizes from about 0.1 mm to about 5 mm. The marble chips can be prepared by a conventional method. For example, the marble chips is prepared by mixing 100 parts

by weight of acrylic resin, 120 to 200 parts by weight of an inorganic filler, 0.1 to 10 parts by weight of a cross linking agent and 0.1 to 10 parts by weight of an initiator, curing the mixture and pulverizing the cured material.

In another embodiment, such marble chips may have sizes from about 0.1 mm to about 1.0 mm.

The marble chips may be added in an amount of about 0 to 200 parts by weight, preferably about 0.1 to 150 parts by weight, more preferably about 0.1 to 70 parts by weight, per 100 parts by weight of acrylic resin to provide an artificial marble with various patterns.

The artificial marble of the present invention can be prepared by a conventional method. For example, all the components and additives are mixed together to obtain a slurry of artificial marble. Then the slurry is poured into a molding cell, followed by curing to form artificial marble product.

The invention may be better understood by reference to the following examples which are intended for the purpose of illustration and are not to be construed as in any way limiting the scope of the present invention, which is defined in the claims appended hereto. In the following examples, all parts and percentage are by weight unless otherwise indicated.

Examples

Example 1

100 parts by weight of methyl methacrylate resin syrup consisting of a mixture of 30 % of poly methyl methacrylate and 70 % of methyl methacrylate, 20 parts by weight of loess powder having an average particle size of 30 μm, 155 parts by weight of a mixture consisting of marble chips having particle sizes of 0.1 to 5 mm and aluminium hydroxide, 2 parts by weight of trimethylolpropane

tri(meth)acrylate and 2 parts by weight of lauroyl peroxide were mixed, and stirred by a mixer to obtain a mixed slurry. The mixed slurry was poured into a glass molding cell having a size of 300 im x 600 mm x l5 mm, and cured in an oven at 45 ^° C , then the mixed slurry was gradually heated up to 100 ^° C . The cured mixed slurry was cooled to room temperature to obtain a solid surface article in the form of a flat plate. The resulting solid surface article had unique and refined ocher texture. The photograph of the solid surface article is shown in Figure 1.

Example 2

Example 2 was prepared in the same manner as in Example 1 except that 10 parts by weight of loess powder having an average particle size of 10 μm was used.

Comparative Example 1

Comparative Example 1 was prepared in the same manner as in Example 1 except that 50 parts by weight of loess powder was used.

Comparative Example 2

Comparative Example 2 was prepared in the same manner as in Example 2 except that loess powder having an average particle size of 80 μm was used.

The flexural strength and impact strength of the solid surface articles of Examples 1-2 and Comparative Examples 1-2 were determined by ASTM 790 and ASTM 256 respectively and are as follow:

Table 1

As shown in Table 1 , Comparative Example 1 using an excessive amount of loess shows that the flexural and the impact strengths were degraded. Comparative Example 2 employing excessively large particles having a diameter of greater than 50 μm shows that the flexural and the impact strengths were also deteriorated.

The present invention can be easily carried out by an ordinary skilled person in the art. Many modifications and changes may be deemed to be with the scope of the present invention as defined in the following claims.