JP4872578B2 - Artificial marble composition, artificial marble and bathtub - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition for an artificial marble having excellent antifouling properties. <P>SOLUTION: The composition for artificial marble comprises an acrylic resin composed of acrylic monomers having a hydroxyl group or a nitrogen-containing group by 10 pts.wt. or more based on 100 pts.wt. of a resin for artificial marble. Further, (i) the acrylic resin has a glass transition point temperature of &ge;-5&deg;C, (ii) the value of a contact angle to water in the surface after polymerization hardening is &le;70&deg;, and (iii) the value of a contact angle against oleic acid in the surface after polymerization hardening is &le;20&deg;. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a composition for artificial marble, artificial marble and a bathtub.

  Artificial marble is used in bathtubs, kitchen sink counters, washstand counters, etc., but in such applications there are many opportunities to come in contact with water containing dirt and foreign matter, so the surface of artificial marble is contaminated. Easy to handle and difficult to remove because the attached dirt is difficult to remove.

  For example, it is often the case that dirt easily adheres to the inner wall surface of a bathtub, particularly the water line in contact with the water surface in the bathtub. The cause of dirt common to bathtub materials has not been sufficiently elucidated due to the complexity of the composition of dirt components and the mechanism of dirt adhesion, but in general, dirt caused by fats and oils or soap scum is included. Various plastic materials, wood materials, and the like are used as the bathtub material, but there are many cases where measures against dirt are not taken, and the conventional bathtub materials are easily contaminated.

  When such dirt adheres to the bathtub, it not only impairs the beauty of the bathtub, but also has a hygienic problem. Moreover, these dirt cannot be removed easily, for example, the dirt adhering to the waterline area of the bathtub often sticks to the bathtub and cannot be easily wiped off.

  In order to solve these problems, Japanese Patent Laid-Open No. 2002-069378 (Patent Document 1) discloses a method of making a surface of a bathtub or the like water repellent using a silicon resin compound, a fluororesin compound, or the like. . In this method, the surface free energy is lowered and the antifouling property is improved by covering the surface of a bathtub or the like with these compounds.

  In another method disclosed in Japanese Patent Application Laid-Open No. 10-166495 (Patent Document 2), a layer containing photocatalyst particles is formed on the surface, the surface of the substance is hydrophilized by photocatalytic action, and dirt is hardly adhered. ing.

JP 2002-069378 A Japanese Patent Laid-Open No. 10-166495

  However, the method of making the surface of a bathtub or the like water-repellent using a silicon resin compound or a fluororesin compound as described above cannot actually provide sufficient antifouling properties, and in particular, stains in the waterline area of the bathtub. Could not be prevented.

  Further, the method of hydrophilizing the material surface by photocatalytic action has a problem that the antifouling effect tends to be insufficient due to insufficient light quantity of the light source in the bathroom or deterioration of the bathtub material itself due to the photocatalytic action.

  The present invention has been made in view of such technical problems. The object of the present invention is to provide a composition for artificial marble having excellent antifouling properties and a composition for curing the artificial marble. Another object of the present invention is to provide an artificial marble and a bathtub using the artificial marble.

That is, the composition for artificial marble according to the present invention is a composition for artificial marble containing 10 parts by weight or more of an acrylic resin composed of an acrylic monomer having a hydroxyl group or a nitrogen-containing group with respect to 100 parts by weight of acrylic syrup ,
(i) The glass transition temperature of the acrylic resin is −5 ° C. or higher, preferably 0 ° C. or higher.
(ii) The value of the contact angle with water on the surface after polymerization curing is 70 ° or less, and
(iii) The contact angle with oleic acid is 20 ° or less.

  Acrylic resins include acrylic acid ester polymers and methacrylic acid ester polymers, but acrylic resins composed of acrylic monomers having hydroxyl groups or nitrogen-containing groups used in the artificial marble composition of the present invention include methacrylic esters. An acrylic resin composed of an acid ester monomer is preferred. As an acrylic monomer (methacrylic acid ester monomer) having a hydroxyl group, for example, GE-610 manufactured by Mitsubishi Gas Chemical Co., Ltd. is available. Examples of the acrylic monomer having a nitrogen-containing group (methacrylic acid ester monomer) include GE-710 and GE-720 manufactured by Mitsubishi Gas Chemical Co., Ltd.

The composition for artificial marble of the present invention contains 10 parts by weight or more of an acrylic resin composed of an acrylic monomer having a hydroxyl group or a nitrogen-containing group with respect to 100 parts by weight of acrylic syrup (hereinafter sometimes referred to as the acrylic resin). Therefore, when artificial marble is produced by polymerizing and curing this artificial marble composition, the value of the contact angle with water on the surface is 70 ° or less and the value of the contact angle with oleic acid is 20 ° or less. An artificial marble molded body can be obtained. There is a strong correlation between the water contact angle and the oleic acid contact angle of artificial marble and the antifouling property, and the smaller the values of the water contact angle and the oleic acid contact angle, the better the antifouling property. Therefore, the artificial marble excellent in antifouling property can be obtained by containing 10 parts by weight or more of the acrylic resin with respect to 100 parts by weight of acrylic syrup .

Further, if 60 parts by weight or more of an acrylic resin composed of an acrylic monomer having a hydroxyl group or a nitrogen-containing group is mixed with 100 parts by weight of acrylic syrup , the value of the contact angle with water on the surface after polymerization curing is 55 ° or less. Moreover, the value of the contact angle with oleic acid is 15 ° or less, and the antifouling property of the artificial marble molded body is further improved.

  Moreover, when the glass transition point temperature of the acrylic resin which consists of an acrylic monomer which has a hydroxyl group or a nitrogen-containing group is lower than -5 degreeC, the moldability of an artificial marble molded object will be inferior and antifouling property will fall considerably. On the other hand, if the acrylic resin having a glass transition temperature of −5 ° C. or higher is used, the moldability is improved and the antifouling property is improved. Furthermore, if the said acrylic resin whose glass transition temperature is 0 degreeC or more is used, a moldability will become still better.

  Artificial marble can be obtained by polymerizing and curing the composition for artificial marble of the present invention, and a desired artificial marble molded body can be obtained by polymerizing and curing the composition for artificial marble and molding into a desired shape. . For example, at least the surface portion of the bathtub (surface protective layer, bathtub wall material, etc.), the counter of the kitchen sink, the counter of the wash basin, etc. can be formed from artificial marble.

  According to the composition for artificial marble of the present invention, it was possible to obtain a molded article of artificial marble which hardly adheres to dirt and easily removes dirt. In particular, when used in a bathtub, the effect of preventing dirt in the waterline area on the inner surface of the bathtub was very high. And according to the composition for artificial marble of this invention, the moldability of an artificial marble molded object does not deteriorate. Furthermore, since the composition for artificial marble of the present invention does not utilize photocatalytic action, there is no problem that the antifouling effect is lowered due to insufficient light amount of the light source or deterioration of the photocatalytic action.

  Hereinafter, preferred embodiments of the present invention will be described, but the present invention is not limited to the following descriptions.

  The composition for artificial marble according to the present invention is obtained by mixing an artificial marble resin with an acrylic resin made of an acrylic monomer having a hydroxyl group, or an acrylic monomer having a nitrogen-containing group (particularly an amino group) in an artificial marble resin. A mixture of acrylic resins. Here, the resin for artificial marble may be a thermosetting resin or a thermoplastic resin generally used as a resin for molding an artificial marble bathtub or counter. As the resin for artificial marble, for example, acrylic syrup obtained by dissolving an acrylic polymer in a monomer such as methyl methacrylate, an unsaturated polyester resin, an epoxy resin, or the like can be used.

  Examples of the acrylic resin comprising an acrylic monomer having a hydroxyl group or a nitrogen-containing group include a polymer of an acrylate ester monomer and a polymer of a methacrylate ester monomer. The composition for artificial marble of the present invention includes a hydroxyl group or nitrogen. An acrylic resin composed of a methacrylic acid ester monomer having a containing group is desirable.

Examples of the acrylic monomer having a hydroxyl group include a methacrylic acid ester monomer [for example, GE-610 manufactured by Mitsubishi Gas Chemical Co., Ltd.] represented by a structural formula shown by the following chemical formula 1, and is composed of an acrylic monomer having a hydroxyl group. The acrylic resin is obtained by polymerizing such a methacrylic acid ester monomer.

As an acrylic monomer having a nitrogen-containing group, for example, a methacrylic acid ester monomer represented by a structural formula shown by the following chemical formula 2 [for example, GE-710 manufactured by Mitsubishi Gas Chemical Co., Ltd.], or a chemical formula 3 shown below There is a methacrylic acid ester monomer represented by such a structural formula [for example, GE-720 manufactured by Mitsubishi Gas Chemical Co., Ltd.], and an acrylic resin composed of an acrylic monomer having a nitrogen-containing group polymerizes such a methacrylic acid ester monomer. It has been made.

  The composition of the composition for artificial marble according to the present invention is such that the acrylic resin comprising an acrylic monomer having a hydroxyl group or a nitrogen-containing group is 10 parts by weight or more with respect to 100 parts by weight of the resin for artificial marble, and more preferably 60 parts by weight. More than a part. As the upper limit of the amount of acrylic resin comprising an acrylic monomer having a hydroxyl group or a nitrogen-containing group, the antifouling effect has been confirmed up to 80 parts by weight with respect to 100 parts by weight of the resin for artificial marble. It is believed that the value can be greater than 80 parts by experiment.

  Therefore, in the composition for artificial marble of the present invention, the resin for artificial marble may be the main resin, and the acrylic resin may be the main resin. However, when the acrylic resin is used as the main resin of the composition for artificial marble, if the strength after polymerization and curing is insufficient, a curing agent or a crosslinking agent is used, and further, a three-dimensional network structure is formed. By doing so, the strength can be improved. Further, when there is a concern about heat resistance or water resistance from the viewpoint of long-term use, it is desirable that the artificial marble is similarly made into a high-density three-dimensional network structure using a curing agent or a crosslinking agent.

  Moreover, the glass transition point temperature of the acrylic resin which consists of the acrylic monomer which has a hydroxyl group or nitrogen-containing group used for the composition for artificial marble of this invention is -5 degreeC or more, More preferably, it is 0 degreeC or more. If the glass transition temperature of the acrylic resin is lower than −5 ° C., the strength of the molded article of the artificial marble is remarkably lowered and the moldability is considerably deteriorated. Further, when the glass transition temperature is lower than −5 ° C., the hydrophilic functional group is difficult to effectively orient on the surface of the artificial marble, so that the surface of the artificial marble is likely to be contaminated, and the antifouling is prevented. Sexuality gets worse. In addition, the upper limit value of the glass transition temperature could not be found within the range of acrylic resins made of commonly used acrylic monomers.

  In the composition for artificial marble of the present invention, an appropriate amount of a coarsely pulverized product, inorganic filler particles, a curing agent and the like for producing a texture of a stone-like artificial marble is appropriately added according to the intended use. The coarsely pulverized product for producing the texture of the stone-like artificial marble includes coarsely pulverized products such as natural product silica, cryogenic stone, meteorite, and resin cured product. Moreover, as an inorganic filling particle added to the composition for artificial marble, glass frit, silica, aluminum powder, aluminum hydroxide and the like can be used. The surface of the inorganic filler particles is preferably subjected to a coupling treatment by an appropriate surface treatment method so as to be well compatible with an artificial marble resin or the like. The coupling treatment may be performed by a commonly used method such as a dry method or a wet method using a commonly used silane or titanate coupling treatment agent.

  As the curing agent, an appropriate amount of Perkadox 16 or Trigonox 121 manufactured by Kayaku Akzo Co., Ltd. may be used, and an appropriate amount of an isocyanate curing agent (Coronate HX) manufactured by Nippon Polyurethane Industry may be used as needed.

  In order to obtain a molded article of artificial marble using the composition for artificial marble as described above, inorganic filler particles and a curing agent are added to the resin for artificial marble and the acrylic resin prepared to have the above composition. Then, the artificial marble composition is uniformly stirred to uniformly disperse the inorganic filler particles and the like.

  As a method of stirring the inorganic filler particles and uniformly dispersing them in the resin for artificial marble and the acrylic resin, a non-dispersing mixer, Henschel mixer, planetary mixer, ball mixer, bead mill, omni mixer, vibration / centrifugal force, etc. are used. A generally used dispersing / stirring device such as a media-based dispersing / stirring device may be used and stirred uniformly for an appropriate time.

  After that, the artificial marble composition is injected into a mold, polymerized and cured, and molded into a predetermined product shape. Then, an artificial marble molded body, for example, an artificial marble bathtub or bathtub wall material, a kitchen sink counter, a washbasin It is possible to produce a watering member such as a table counter, a water heater outer wall member, a residential outer wall member, and the like. Moreover, this composition for artificial marble can also be used as a surface protective layer (antifouling layer) by applying or molding to the surface of another resin molded product or core material.

  As the molding method of the artificial marble composition, a casting molding method is most suitable, but other molding methods such as general molding methods such as injection molding, compression molding, and press molding can also be used. Moreover, you may add to the surface of a resin molded product or a core material using coatings, such as a gel coat. In the case of molding by casting, by appropriately setting the mold temperature of the upper and lower molds, an acrylic resin made of an acrylic monomer having a hydroxyl group or a nitrogen-containing group can be effectively oriented on the surface of the artificial marble. .

  In the composition for artificial marble of the present invention, since the acrylic resin comprising an acrylic monomer having a hydroxyl group or a nitrogen-containing group is 10 parts by weight or more with respect to 100 parts by weight of the resin for artificial marble, the polymerization-cured artificial marble Or the value of the contact angle with water when water droplets are attached to the surface (smooth surface) of the molded article of artificial marble is 70 ° or less, and the value of the contact angle with oleic acid when oleic acid is attached to the surface is It becomes 20 degrees or less. Furthermore, if the acrylic resin comprising an acrylic monomer having a hydroxyl group or a nitrogen-containing group is added to 60 parts by weight or more with respect to 100 parts by weight of the resin for artificial marble, the surface (smooth surface) of the polymerization-cured artificial marble or artificial marble molded body ) Has a water contact angle value of 55 ° or less when a water droplet is adhered, and a oleic acid contact angle value of 15 ° or less when oleic acid is adhered to the surface.

  The contact angle refers to an angle formed between the liquid surface and the solid surface when a small droplet is placed on the solid surface and the droplet is maintained in an equilibrium state. The contact angle with water is due to the orientation of the hydroxyl group or nitrogen-containing group in the acrylic resin on the marble surface, and the contact angle with oleic acid is due to the alkyl group in the acrylic resin on the marble surface. This is due to the orientation.

  In order to effectively orient the hydroxyl group or nitrogen-containing group contained in the acrylic resin on the surface of the artificial marble after polymerization and curing, interaction between these functional groups and the resin for artificial marble, steric hindrance, etc. can be used. In addition, there are a method utilizing the difference in viscosity between the resin for artificial marble and the acrylic resin, and a method using a difference in curing speed between the resin for artificial marble and the acrylic resin.

  There is a strong correlation between the contact angle with water and the contact angle with oleic acid on the surface of the artificial marble molded body and the antifouling property, and the smaller the values of the contact angle with water and the contact angle with oleic acid, the more antifouling property is obtained. It becomes good. Thus, by containing 10 parts by weight or more of the acrylic resin with respect to 100 parts by weight of the resin for artificial marble, the contact angle with water becomes 70 ° or less and the contact angle with oleic acid becomes 20 ° or less. Dirty can be obtained. Further, by adding 60 parts by weight or more of the acrylic resin with respect to 100 parts by weight of the resin for artificial marble, the contact angle with water becomes 55 ° or less and the contact angle with oleic acid becomes 15 ° or less, which is even more excellent. Antifouling property can be obtained.

  That is, in such an artificial marble or an artificial marble molded body, hydrophilic functional groups (hydroxyl groups, nitrogen-containing groups) and lipophilic functional groups (alkyl groups) are sufficiently oriented on the surface of the artificial marble. Due to the effect of each functional group oriented on the surface of the artificial marble, the surface is hardly contaminated, and even if it adheres, it can be easily cleaned. In particular, in the case of a bathtub, dirt hardly adheres to the water line area. Further, even if the acrylic resin is mixed with the composition for artificial marble, the heat and water resistance inherent in the resin for artificial marble (especially acrylic) is not impaired, and the resin for artificial marble is further lost. Therefore, a suitable artificial marble can be obtained.

  On the other hand, when the amount of the acrylic resin added to 100 parts by weight of the resin for artificial marble is less than 10 parts by weight, the value of the contact angle with water is greater than 70 °, and the value of the contact angle with oleic acid is Since it becomes larger than 20 ° and hydrophilic functional groups (hydroxyl groups and nitrogen-containing groups) are not sufficiently oriented on the surface of the artificial marble, the antifouling effect is lowered and sufficient antifouling performance cannot be obtained. In particular, in the case of a bathtub made of artificial marble, dirt easily adheres to the waterline area. In addition, the strength of the molded body of artificial marble is likely to decrease, making it difficult to manufacture the molded body.

  By using an acrylic resin composed of an acrylic monomer having a hydroxyl group or a nitrogen-containing group, the mechanism for preventing the adhesion of dirt and facilitating the removal of the dirt is not clear. Presumably, the functional group of the acrylic resin is effectively oriented on the surface of the artificial marble, thereby imparting relatively strong lipophilicity (water repellency) and hydrophilicity at the molecular level to the artificial marble surface. For this reason, it is considered that dirt-containing water hardly adheres to the surface of the artificial marble and the dirt is difficult to adhere. In addition, even when dirt is attached to the surface of the artificial marble, there are many voids between the surface of the marble and the dirt due to the hydrophilicity, and fluid flows in the gap between the dirt and the surface of the artificial marble. Enters and peels off the dirt, which is considered to be easily removed by this cleaning effect. In particular, in the case of a bathtub made of artificial marble, it seems that contamination can be prevented by a self-cleaning effect due to the influence of the bathtub water flowing in the bathtub and the water surface moving up and down in the waterline area.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

  First, as described below, the samples of Examples 1 to 5 and the samples of Comparative Examples 1 and 2 of the present invention were produced. In any of the samples of Examples 1 to 5 and Comparative Examples 1 and 2, 8900 acrylic syrup solution manufactured by Nippon Iupika Co., Ltd. was used as the resin for artificial marble. In Example 1, acrylic resin (glass transition temperature 55 ° C.) composed of methacrylic acid ester monomer series GE-610 manufactured by Mitsubishi Gas Chemical Co., Ltd. is used as the acrylic resin with respect to 100 parts by weight of the resin for artificial marble. 10 parts by weight was added to obtain a sample of an artificial marble composition. This acrylic monomer has the structural formula shown in Chemical Formula 1 above.

  In Example 2, an acrylic resin (glass transition temperature 55 ° C.) composed of methacrylic acid ester monomer series GE-610 manufactured by Mitsubishi Gas Chemical Co., Ltd. is used as the acrylic resin with respect to 100 parts by weight of the artificial marble resin. 60 parts by weight was added to obtain a sample of a composition for artificial marble.

  In Example 3, an acrylic resin (glass transition temperature 55 ° C.) composed of methacrylic acid ester monomer series GE-610 manufactured by Mitsubishi Gas Chemical Co., Ltd. is used as the acrylic resin with respect to 100 parts by weight of the resin for artificial marble. 80 parts by weight were added to obtain a sample of an artificial marble composition.

  In Example 4, an acrylic resin (glass transition temperature 18 ° C.) composed of a methacrylic acid ester monomer series GE-720 manufactured by Mitsubishi Gas Chemical Co., Ltd. is used as the acrylic resin with respect to 100 parts by weight of the artificial marble resin. 60 parts by weight was added to obtain a sample of a composition for artificial marble. This acrylic monomer has the structural formula shown in Chemical Formula 3 above.

  In Example 5, 60 parts by weight of methacrylic acid ester monomer series GE-710 (glass transition temperature -5 ° C.) manufactured by Mitsubishi Gas Chemical Co., Ltd. as the acrylic resin with respect to 100 parts by weight of the resin for artificial marble. This was added to obtain a sample of a composition for artificial marble. This acrylic monomer has the structural formula shown in Chemical Formula 2.

In Comparative Example 1, a sample of the artificial marble composition was obtained using only the artificial marble resin. In Comparative Example 2, 10 parts by weight of methacrylic acid ester monomer series GE-410 (glass transition temperature -65 ° C.) manufactured by Mitsubishi Gas Chemical Co., Ltd. is used as the acrylic resin with respect to 100 parts by weight of the resin for artificial marble. This was added to obtain a sample of a composition for artificial marble. In addition, the methacrylic acid ester monomer series GE-410 made by Mitsubishi Gas Chemical Co., Ltd. has a structural formula as shown in the following chemical formula 4. That is, it is an acrylic monomer having neither a hydroxyl group nor a nitrogen-containing group.

  Furthermore, in each sample of Examples 1 to 5 and Comparative Examples 1 and 2, AS105S (coupled glass frit) manufactured by Tokan Materials Co., Ltd. or an appropriate amount as an appropriate amount of inorganic filler particles after coupling. The curing agent was added. By dispersing and stirring this, a composition for artificial marble in which inorganic filler particles were uniformly dispersed was obtained.

  Next, the resin solution of the artificial marble composition of each sample is put into a casting mold, and the mold temperature and the curing time are adjusted to appropriate values under appropriate pressure. An artificial marble molded body (sample for test) having a thickness of 10 cm and a thickness of about 5 mm was obtained.

Then, using the obtained artificial marble molded bodies of Examples 1 to 5 and Comparative Examples 1 and 2, the value of the contact angle with water, the value of the contact angle with oleic acid, the antifouling performance and the moldability were evaluated. The evaluation results are shown in Table 1 below.

  The contact angle with water was measured by using a contact angle meter CA-MM manufactured by Tatec with water droplets attached on each sample. The water contact angle is divided into three levels (water contact angle). When the water contact angle is 55 ° or less, it is displayed as “◯” (high hydrophilicity) in Table 1, 55 ° When the excess is 70 ° or less, it is indicated by “◯ △” in Table 1, and when it exceeds 70 °, it is indicated by “Δ” in Table 1.

  The contact angle with oleic acid was measured by attaching oleic acid on each sample and using a contact angle meter CA-MM manufactured by Tatec. The contact angle for oleic acid is also divided into three levels (contact angle for oleic acid). If the contact angle for oleic acid is 15 ° or less, it is displayed as “◯” (high lipophilicity) in Table 1. In the case of exceeding 15 ° and not more than 20 °, “◯ △” is shown in Table 1, and in the case of exceeding 20 °, “△” is shown in Table 1.

  Regarding the antifouling performance of the artificial marble molded body, after bathing in a bath at 40 ° C for 10 minutes for a total of 4 people using a whirlpool (jacuzzi) strength, each artificial marble molded body of each sample was placed in the tub waterline. It was immersed in the vicinity and bathed in a hot water bath for 5 minutes. And the glossiness of the surface of the artificial marble molded body taken out from the bathtub was measured with a gloss meter, and the glossiness values before and after the immersion and visual evaluation of dirt were taken into account. In particular, regarding the gloss value, the gloss before immersion is 100%, and when the gloss after immersion is 90% or more, the antifouling performance is evaluated to be excellent. It was. Moreover, when the glossiness after immersion was 80% or more and less than 90%, it was evaluated that the antifouling performance was good. When the glossiness after immersion was 60% or more and less than 80%, it was evaluated that the antifouling performance was poor, and it was represented by “Δ” in Table 1.

  The moldability of the artificial marble molded body was evaluated in three stages according to the demolding condition (ease of demolding) when the artificial marble molded body was demolded from the casting mold. That is, when the mold was easily removed from the casting mold, it was evaluated that the moldability was good, and in Table 1, it was represented by “◯”. When it took some time to remove the mold, it was evaluated that the moldability was within an allowable range, and in Table 1, “Δ” was indicated. When it was not possible to remove the mold (such as when the artificial marble molded body was stuck to the casting mold and could not be removed), the moldability was evaluated as bad (bad).

  If the evaluation result of Examples 1-5 of Table 1 and the comparative example 1 are compared, in Examples 1-5, the addition amount of the acrylic resin which consists of an acrylic monomer which has a hydroxyl group or a nitrogen-containing group with respect to 100 weight part of resin for artificial marble Is 10 parts by weight or more, and the glass transition temperature of the acrylic resin is −5 ° C. or higher. Therefore, the contact angle with water is 70 ° or less, the contact angle with oleic acid is 20 ° or less, and antifouling is achieved. The performance was good. In Examples 1 to 5, the moldability was within the allowable range, but in Examples 1 to 4 in which the glass transition temperature was 0 ° C. or higher, the moldability was also good.

  Comparing the evaluation results of Examples 2 to 5 and Table 1 in Table 1, in Examples 2 to 5, the amount of acrylic resin comprising an acrylic monomer having a hydroxyl group or a nitrogen-containing group with respect to 100 parts by weight of the resin for artificial marble Is 60 parts by weight or more, and the glass transition temperature of the acrylic resin is −5 ° C. or higher, so that the contact angle with water is 55 ° or less and the contact angle with oleic acid is 15 ° or less, which is excellent. Antifouling performance was obtained. Further, in Examples 2 to 5, the moldability was within the allowable range, but in Examples 2 to 4 in which the glass transition temperature was 0 ° C. or higher, the moldability was also good.

  According to Comparative Example 2 in Table 1, the glass transition of the acrylic resin even when the amount of the acrylic resin composed of an acrylic monomer having a hydroxyl group or a nitrogen-containing group is 10 parts by weight or more with respect to 100 parts by weight of the resin for artificial marble. When the spot temperature was lower than −5 ° C., the moldability was poor and the antifouling property was poor.

  In addition, from Table 1, it can also confirm that there exists a strong correlation between a contact angle value with respect to water and a contact angle value with respect to oleic acid, and antifouling performance.

Claims (6)

Containing 10 parts by weight or more of an acrylic resin composed of an acrylic monomer having a hydroxyl group or a nitrogen-containing group with respect to 100 parts by weight of acrylic syrup ;
The glass transition temperature of the acrylic resin is −5 ° C. or higher,
A composition for artificial marble, which has a water contact angle value of 70 ° or less on a surface after polymerization and curing and a oleic acid contact angle value of 20 ° or less.   The composition for artificial marble according to claim 1, wherein the acrylic monomer is a methacrylic acid ester monomer. Wherein the composition of the acrylic syrup and the acrylic resin, wherein the acrylic resin to the acrylic syrup 100 parts by weight of 60 parts by weight or more, artificial marble composition according to claim 1 or 2 . The composition for artificial marble according to any one of claims 1 to 3 , wherein the acrylic resin has a glass transition temperature of 0 ° C or higher. An artificial marble obtained by polymerizing and curing the composition for artificial marble according to any one of claims 1 to 4 . A bathtub in which at least a surface portion is formed by the artificial marble according to claim 5 .