KR20190053690A - Acrylic resin syrup for artificial marble and artificial marble containing the same - Google Patents

Abstract

The present invention relates to an acrylic resin syrup for artificial marble and artificial marble comprising the same. More particularly, the present invention relates to the acrylic resin syrup for artificial marble and the artificial marble comprising the same, which is capable of manufacturing artificial marble having excellent water resistance, chemical resistance, and shrink resistance, and also having excellent mechanical properties.

Description

TECHNICAL FIELD [0001] The present invention relates to an acrylic resin syrup for artificial marble, and an artificial marble comprising the same. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to an acrylic resin syrup for artificial marble and artificial marble comprising the same. More particularly, the present invention relates to an acrylic resin syrup for artificial marble and an artificial marble comprising the same, which is capable of producing artificial marble having excellent water resistance, chemical resistance and shrink resistance, and excellent mechanical properties.

Recently, artificial marbles are widely used as interior materials, and artificial marbles are largely divided into acrylic type and polyester type depending on the kind of base resin used.

The double acrylic based artificial marble is usually prepared by adding an additive such as an inorganic filler to an acrylic resin syrup composed of a mixture of an acrylic polymer and an acrylic monomer and shaping it into a sheet state. When the acrylic polymer is prepared by dissolving the acrylic polymer in the acrylic monomer, the viscosity of the resin syrup is high, and the content of the inorganic filler is limited in the production of artificial marble.

Also, when the prepolymer is polymerized to prepare a prepolymer and used as a resin syrup, there is a problem in that mechanical properties are lowered when the molecular weight of the prepolymer is lowered in order to produce resin syrup having a lower viscosity in order to increase the content of the inorganic filler. There is a problem that shrinkage after curing is largely generated when the content is used in a minimized amount.

The present invention relates to an acrylic resin syrup for artificial marble which is capable of further increasing the content of an inorganic filler as compared with conventional artificial marble and producing an artificial marble excellent in water resistance, chemical resistance and shrink resistance, And to provide artificial marble comprising the same.

The present invention also provides an acrylic resin syrup for artificial marble and an artificial marble comprising the acrylic resin syrup, which can achieve all of the physical properties by polymerizing a specific combination of monomers to prepare a prepolymer and using the same as a resin syrup.

In addition, the present invention provides an acrylic resin syrup for artificial marble which can further reduce the production cost of artificial marble because the content of the inorganic filler can be further increased as compared with the conventional resin syrup while the viscosity of the resin syrup is low, And an artificial marble comprising the same.

In order to achieve the above object, the present invention relates to an acrylic resin syrup for artificial marble comprising a prepolymer having a weight average molecular weight of 5,000 to 150,000 obtained by polymerizing a monomer mixture containing tert-butyl methacrylate and methyl methacrylate and an initiator .

The present invention also relates to an artificial marble comprising the acrylic resin syrup for the artificial marble.

The artificial marble produced by using the acrylic resin syrup for artificial marble of the present invention is excellent in water resistance, chemical resistance and shrink resistance, and has excellent mechanical properties.

Further, the acrylic resin syrup for artificial marble of the present invention is low in viscosity and excellent in physical properties such as water resistance and shrinkage resistance, so that the content of the inorganic filler can be further increased when producing artificial marble.

Hereinafter, the present invention will be described in more detail by way of concrete examples or examples. It should be understood, however, that the invention is not limited thereto and that various changes and modifications may be made without departing from the spirit and scope of the invention.

Unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention is merely intended to effectively describe a specific embodiment and is not intended to limit the invention.

Also, the singular forms as used in the specification and the appended claims are intended to include the plural forms as well, unless the context clearly indicates otherwise.

One embodiment of the present invention is an acrylic resin syrup for artificial marble comprising a prepolymer having a weight average molecular weight of 5,000 to 150,000 obtained by polymerizing an initiator and a monomer mixture containing tert-butyl methacrylate and methyl methacrylate.

In one embodiment of the present invention, the acrylic resin syrup may have a viscosity of not more than 1000 cP measured at 25 캜.

In one embodiment of the present invention, the acrylic resin syrup has a conversion of 10 To 35%. ≪ / RTI >

In one embodiment of the present invention, the monomer mixture may be 20 to 80 wt% of tert-butyl methacrylate and 20 to 80 wt% of methyl methacrylate.

In one embodiment of the present invention, the monomer mixture comprises 20 to 80% by weight of tert-butyl methacrylate, 15 to 79% by weight of methyl methacrylate, and at least one of ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate 1 to 5 of any one or two or more acrylic monomers selected from the group consisting of 2-ethylhexyl methacrylate, benzyl methacrylate, methyl acrylate, isooctyl acrylate, ethyl acrylate, n-butyl acrylate, % ≪ / RTI > by weight.

Another embodiment of the present invention is an artificial marble comprising the acrylic resin syrup for the artificial marble.

In one embodiment of the present invention, the artificial marble may include an acrylic resin syrup for the artificial marble, an inorganic filler, and an initiator.

In one embodiment of the present invention, the artificial marble may contain 1.1 to 2 times the content of the inorganic filler based on the weight of the acrylic resin syrup for artificial marble.

In one embodiment of the present invention, the artificial marble has a shrinkage according to ASTM D 792-08A of 14% or less, a water resistance after 24 hours according to ASTM D 570-98 of 0.04% or less, The number of cracks of 2 mm or more after immersion in 100% ethanol for 3 hours may be 5 or less.

Hereinafter, each configuration of the present invention will be described in more detail.

The inventors of the present invention have studied to provide an acrylic resin syrup for lowering the viscosity of an acrylic resin syrup for manufacturing artificial marble and manufacturing artificial marbles having excellent shrink resistance, water resistance, chemical resistance and mechanical strength. As a result, when a specific combination of monomers is used, mechanical properties similar to those of conventional resin syrups can be exhibited. At the same time, water resistance and shrinkage resistance are further improved, and resin syrup viscosity is low. The content can be further increased and the present invention has been completed.

That is, the present invention is characterized in that tert-butyl methacrylate and methyl methacrylate are used in combination as a monomer for producing an acrylic resin syrup. In particular, when n-butyl methacrylate or isobutyl methacrylate was used, it was impossible to use it as artificial marble because the glass transition temperature was low at room temperature. However, when tert-butyl methacrylate was used, the glass transition temperature Since a prepolymer having a melting point of 100 ° C or higher is produced, it exhibits mechanical strength substantially equal to that of an acrylic polymer, and has excellent physical properties such as water resistance, shrinkage resistance and chemical resistance.

In one embodiment of the present invention, the monomer used in the acrylic resin syrup for artificial marble may be one using tert-butyl methacrylate and methyl methacrylate. More specifically, the monomer mixture may be 10 to 90% by weight of tert-butyl methacrylate and 10 to 90% by weight of methyl methacrylate, more preferably 20 to 80% by weight of tert-butyl methacrylate, And 20 to 80% by weight of methacrylate. As the content of tert-butyl methacrylate increases, a polymer having lower shrinkage and water resistance can be produced. Further, shrinkability is further improved in the range of from 20 to 80% by weight of tert-butyl methacrylate, But is not limited to, water resistance as well as mechanical properties such as impact resistance and surface hardness.

In one embodiment of the present invention, the monomer mixture may further include an acrylic monomer conventionally used in addition to tert-butyl methacrylate and methyl methacrylate. Specific examples thereof include ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, benzyl methacrylate, methyl acrylate, isooctyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, and the like, but is not limited thereto. When these monomers are further included, they may be used in an amount of 5% by weight or less, more specifically 1 to 5% by weight, based on the total monomer mixture. Also, even if the acrylic monomer is further included, the content of tert-butyl methacrylate is preferably in the range of 20 to 80% by weight of the total monomer mixture. Specifically, for example, the monomer mixture may comprise 20 to 80 wt.% Of tert-butyl methacrylate, 15 to 79 wt.% Of methyl methacrylate and 1 to 20 wt.% Of ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 1 to 5 weight percent of one or more acrylic monomers selected from 2-ethylhexyl methacrylate, benzyl methacrylate, methyl acrylate, isooctyl acrylate, ethyl acrylate, n-butyl acrylate and isobutyl acrylate %. ≪ / RTI > The resin composition of the present invention can provide resins having excellent shrinking properties, water resistance, chemical resistance, and mechanical properties within the above range, and is not limited thereto.

In one embodiment of the present invention, the acrylic resin syrup for artificial marble is prepared by polymerizing the monomer mixture and the initiator, wherein the polymerization is stopped when the conversion is 10 to 35% to prepare the prepolymer . The prepolymer having a weight average molecular weight of 5,000 to 150,000 in the above conversion range can be prepared, and inorganic fillers and pigments can be easily dispersed, but the present invention is not limited thereto. The prepolymer means a liquid polymer having a conversion of 10 to 35% and not a solid polymer. In the present invention, the prepolymer may be used as it is as a resin syrup, and a resin syrup having a low viscosity may be provided without adding a separate solvent.

In one embodiment of the present invention, the acrylic resin syrup may have a weight average molecular weight of 5,000 to 150,000, more specifically 8,000 to 120,000. When the viscosity measured at 25 캜 in the above range is 1000 cP Or less and has a viscosity suitable for use as a resin syrup and can increase the content of the inorganic additive in the artificial marble production in the future, but is not limited thereto.

In one embodiment of the present invention, the acrylic resin syrup may have a viscosity measured at 25 캜 of 1000 cP or less, specifically 10 to 1000 cP, more specifically 50 to 500 cP. Since the acrylic resin syrup of the present invention does not contain an acrylic polymer, the viscosity of the acrylic resin syrup is low and thus the content of the inorganic filler can be further increased in the production of artificial marble. When the content of the inorganic filler is increased, the cost is reduced but the water resistance is low and the shrinkage may occur. The present invention can solve this problem by using specific monomers in combination.

In one embodiment of the present invention, the initiator used in the polymerization of the acrylic resin syrup may be used without limitation as long as it is an initiator usually used in acrylic resin polymerization. Specifically, for example, a peroxide initiator, an azo initiator, and the like can be used. More specifically, for example, peroxides such as benzoyl peroxide, lauroyl peroxide, butyl hydroperoxide and cumyl hydroperoxide, and azo compounds such as azobisisobutylonitrile (AIBN) can be used. It is not. The initiator may be used in an amount of 0.01 to 1 part by weight based on 100 parts by weight of the monomer mixture. The amount of the initiator can be controlled within the above range and the syrup having a low viscosity can be easily prepared, .

In one embodiment of the present invention, the prepolymer may further include a crosslinking agent as needed in the polymerization. The type of the cross-linking agent is not limited as long as it is a cross-linking agent such as a conventionally used polyfunctional monomer, a polyfunctional oligomer, or a mixture thereof. Specifically, there may be mentioned, for example, divinylbenzene, ethylene glycol dimethacrylate, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, ethylene glycol diacrylate, petaerythritol triacrylate, trimethylene propyl tri Acrylate, propoxylated glycerol triacrylate, trimethylopropaneethoxy triacrylate, propoxylated glycerol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hydroxy pentaacrylate, and dipentaerythritol hexa And the like can be used. The content of the crosslinking agent may be 0.1 to 1 part by weight, more specifically 0.2 to 0.5 part by weight, based on 100 parts by weight of the monomer mixture. The molecular weight and the viscosity can be appropriately prepared within the above range, and thus the present invention is not limited thereto.

In the production of the acrylic resin syrup in one aspect of the present invention, Deg.] C to 100 < 0 > C, more specifically 70 to 90 [deg.] C, and the polymerization can be stably carried out in the above range. It may also be quenched after polymerization and is preferably, but not limited to, quenched to prevent further polymerization. The quenching temperature may be 10 to 30 ° C, but is not limited thereto.

The present invention also includes an artificial marble comprising the acrylic resin syrup. More specifically, the artificial marble is prepared by putting a mixture containing acrylic resin syrup, inorganic filler and initiator for artificial marble into a mold and curing .

In one embodiment of the present invention, the inorganic filler contained in the artificial marble may be used without limitation as long as it is commonly used in artificial marble. Specifically, it is possible to use, for example, any one or a mixture of two or more selected from calcium carbonate, aluminum hydroxide, silica, alumina, barium sulfate, magnesium hydroxide and the like, but is not limited thereto.

In one embodiment of the present invention, the artificial marble maintains dispersion and flowability even when the content of the inorganic filler is 1.1 to 2 times, more specifically 1.5 to 2 times, based on the weight of the acrylic resin syrup for artificial marble , It is possible to provide an artificial marble excellent in water resistance and chemical resistance. In addition, even when used in the above-mentioned range, the viscosity of the mixture for producing artificial marble can be less than 5000 cP, specifically 1000 to 5000 cP, more specifically 1500 to 3000 cP. have.

In one embodiment of the present invention, the initiator contained in the artificial marble is not limited as long as it is an initiator usually used in artificial marble. More specifically, the above-described peroxide initiator, azo initiator, and the like can be used. More specifically, for example, peroxides such as benzoyl peroxide, lauroyl peroxide, butyl hydroperoxide and cumyl hydroperoxide, and azo compounds such as azobisisobutylonitrile (AIBN) can be used. It is not.

In one embodiment of the present invention, the artificial marble is not limited as long as it is an additive conventionally used in the field. Specifically, it may further include, for example, marble chips, coloring agents, crosslinking agents, and the like, and the kind and content thereof are not limited as long as they do not impair the intended physical properties.

The artificial marble according to one embodiment of the present invention has a shrinkage according to ASTM D 792-08A of 14% or less, more specifically 5 to 14%, based on a 10 mm thick specimen, after 24 hours according to ASTM D 570-98 The water resistance is 0.04% or less, more specifically 0.01 to 0.04%, and the number of cracks of 2 mm or more after immersion in 100% ethanol for 5 hours or less, more specifically, 0 to 5 can be satisfied.

Hereinafter, the present invention will be described in more detail based on examples and comparative examples. However, the following examples and comparative examples are merely examples for explaining the present invention in more detail, and the present invention is not limited by the following examples and comparative examples.

The following physical properties were measured as follows.

1) Shrinkage resistance

The physical properties were measured according to ASTM D 792-08A.

With respect to the volume of the mold, the volume of the molded article was measured and calculated as follows.

Shrinkage resistance (%) = volume of molded article / volume of mold × 100

2) Water resistance

The physical properties after 24 hours according to ASTM D 570-98 were measured as the water absorption rate.

3) Chemical resistance

It was measured according to ASTM 638.

After the Type A tensile specimen was prepared, it was bonded to a 1.5% strain JIG and immersed in 100% ethanol for 3 hours. The degree of cracking on the specimen was visually observed and the number of cracks exceeding 2 mm was measured.

4) Impact resistance

The Izod impact strength was measured according to ASTM D 526-06 ae1 (Method A).

5) Surface hardness measurement

Barcol hardness was measured according to ASTM D 2583-07.

6) Weight average molecular weight

The syrup was dissolved in tetrahydrofuran and measured by gel chromatography.

The weight average molecular weight was measured using a gel permeation chromatography (GPC) instrument manufactured by Waters. The instrument consisted of a mobile phase pump (M515 Pump), a column heater (ALLCOLHTRB), a detector (2414 RI Detector) and an injector (2695 EB automatic injector). The analytical column used was Styragel HR from WATERS. (PMMA) American polymer standard corporation STD. As the mobile phase solvent, HPLC grade tetrahydrofuran (THF) is used and the column heater temperature is 40 ° C and the mobile phase solvent flow rate is 1.0 mL / min. The copolymer prepared for the sample analysis was dissolved in tetrahydrofuran (THF), which is a mobile phase solvent, and then injected into a GPC machine to measure the weight average molecular weight.

7) Viscosity

The syrup itself was measured at 25 캜 using a Brookfield viscometer. The spindle number was 3.

[Examples 1 to 5]

1) Preparation of acrylic resin syrup

Methyl methacrylate and tert-butyl methacrylate were mixed in the amounts shown in Table 1 below to prepare a monomer mixture. 10 parts by weight of azobisisobutyronitrile as an initiator and 0.2 parts by weight of ethylene glycol dimethacrylate as a crosslinking agent were added to the monomer mixture, and the mixture was stirred at 80 DEG C for 4 hours and then cooled rapidly to 20 DEG C to prepare an acrylic resin syrup. The physical properties of the prepared acrylic resin syrup were measured and are shown in Table 1 below.

2) Manufacture of artificial marble

100 parts by weight of aluminum hydroxide having an average particle diameter of 60 占 퐉 as an inorganic filler and 100 parts by weight of azobisisobutyronitrile as an initiator were mixed and stirred with respect to 100 parts by weight of the acrylic resin syrup prepared above.

The mixture was injected between glass molds having a thickness of 10 mm and then cured in a water bath at 80 DEG C for 3 hours.

After the curing, the mold was put into an oven at 90 ° C to be secondary-cured.

The physical properties of the manufactured artificial marble were measured and are shown in Table 1 below.

[Example 6]

Except that 200 parts by weight of aluminum hydroxide having an average particle size of 60 占 퐉 was used as an inorganic filler as shown in Table 1 below.

[Comparative Example 1]

The procedure of Example 1 was repeated except that methyl methacrylate alone was used in the preparation of the acrylic resin syrup.

The properties are shown in Table 1 below.

[Comparative Example 2]

The procedure of Example 1 was repeated except that methyl methacrylate and n-butyl acrylate were used in an 80:20 weight ratio in the preparation of acrylic resin syrup.

The properties are shown in Table 1 below.

[Comparative Example 3]

The procedure of Example 1 was repeated, except that polymethylmethacrylate and methylmethacrylate were mixed at a weight ratio of 30:70 in preparing an acrylic resin syrup.

The properties are shown in Table 1 below.

Example 1
Example 2
Example 3
Example 4
Example 5
Example 6
Comparative Example 1
Comparative Example 2
Comparative Example 3
Monomers (weight ratio)
MMA /
t-BMA
90/10
MMA /
t-BMA
80/20
MMA /
t-BMA
50/50
MMA /
t-BMA
20/80
MMA /
t-BMA
10/90
MMA /
t-BMA
50/50
MMA 100
MMA /
n-BMA
80/20
PMMA /
MMA
30/70
Inorganic filler content
(Weight ratio)
1x
1x
1x
1x
1x
Twice
1x
1x
1x
Resin syrup
Viscosity
(cP)
450
400
250
200
200
250
1100
830
1200
Molecular Weight
100,000
100,100
100,200
100,100
100,000
100,000
100,000
100,000
100,000
Conversion Rate
(%)
25
25
25
25
25
25
25
25
-
Artificial marble
Shrinkage rate
(%)
7.5
7.4
6.1
5.4
5.8
4.7
10.5
11
7.8
Water resistance
(%)
0.04
0.01
0.01
0.01
0.02
0.01
0.04
0.04
0.40
Chemical resistance
(dog)
5
3
3
2
2
One
20
26
23
Izod impact strength
(J / m)
17
17
17
15
11
12
17
12
17
Barcol hardness
60
63
61
57
40
60
60
30
57

As shown in Table 1, it was confirmed that artificial marble having excellent shrinkage, water resistance, chemical resistance and mechanical strength can be provided when producing artificial marble using resin syrup using the prepolymer according to the present invention.

When methyl methacrylate alone was used as in Comparative Example 1, it was found that the shrinkage ratio was high, the water resistance was high, and the chemical resistance was poor. In the case of using normal butyl acrylate as in Comparative Example 2, it was found that the viscosity of the resin syrup was high, the shrinkage ratio was high, and the chemical resistance was poor. Also, it was confirmed that it is difficult to use as an artificial marble because its hardness is low due to its low glass transition temperature. When the polymethylmethacrylate resin is used in the form of the methyl methacrylate monomer as in Comparative Example 3, the viscosity is higher than 400 cP, which limits the increase of the content of the inorganic filler. It was confirmed that the water resistance and the chemical resistance were poor.

Claims (9)

acrylic acid resin syrup for artificial marble comprising a prepolymer having a weight average molecular weight of 5,000 to 150,000 obtained by polymerizing an initiator and a monomer mixture comprising tert-butyl methacrylate and methyl methacrylate. The method according to claim 1,
Wherein the acrylic resin syrup has a viscosity of not more than 1000 cP measured at 25 캜. The method according to claim 1,
The acrylic resin syrup had a conversion of 10 To 35% by weight of the acrylic resin syrup for artificial marble. The method according to claim 1,
Wherein the monomer mixture is 20 to 80 wt% of tert-butyl methacrylate and 20 to 80 wt% of methyl methacrylate. 5. The method of claim 4,
Wherein the monomer mixture comprises 20 to 80% by weight of tert-butyl methacrylate, 15 to 79% by weight of methyl methacrylate and at least one of ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 1 to 5% by weight of any one or two or more acrylic monomers selected from the group consisting of methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, methyl acrylate, isooctyl acrylate, Acrylic resin syrup for artificial marble. An artificial marble comprising an acrylic resin syrup for artificial marble of any one of claims 1 to 5. The method according to claim 6,
Wherein said artificial marble is made of acrylic resin syrup, inorganic filler and initiator for said artificial marble. 8. The method of claim 7,
Wherein the content of the inorganic filler is 1.1 to 2 times the weight of the acrylic resin syrup for artificial marble. 8. The method of claim 7,
The artificial marble has a shrinkage ratio of 14% or less according to ASTM D 792-08A, a water resistance of 0.04% or less after 24 hours according to ASTM D 570-98, and immersing in 100% ethanol for 3 hours Artificial marble with a crack size of 5mm or less after 2mm.