JPH10217264A - Method for continuously producing acrylic resin artificial marble panel and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continuously produce an acrylic resin artifical marble panel with high productivity. SOLUTION: An acrylic resin artificial marble panel polymerizable raw material mixture is continuously injected into continuous curing apparatuses 7-10 constituted of one sets of endless steel belts 1 and accessory devices and continuously cured corresponding to the movement of the steel belts to produce a plate-shaped semi-manufactured product which is, in turn, passed through an edge trimming and surface polishing process to continuously produce an acrylic resin artificial marble panel. In this method, two or more regions are provided and curing chambers each provided with an air circulating apparatus consisting of a blower 21, a heater 23, a circulating duct 22 and nozzle units 11, 11" are provided to the respective regions so as to be symmetrically provided to the upper and rear surfaces of one set of the endless steel belts 1 having the raw material mixture applied thereto and the upper and rear surfaces of the polymerizable raw material are heated by hot air at the same time to be cooled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for continuously producing an artificial marble plate using an acrylic resin composition, and more particularly, to a mixture of an acrylic polysynthetic resin and a large amount of an inorganic filler. And a continuous method for producing an acrylic resin artificial marble plate, characterized by using a continuous curing device using a set of endless steel belts.

[0002]

2. Description of the Related Art Acrylic resin artificial marble board is made by mixing a large amount of a powdered inorganic filler, a marble chip developing particle (Marble Chip), various additives, a curing initiator, a pigment, and the like into an acrylic polymer resin. After preparing a slurry-like mixture, injecting it into a mold and curing it with an appropriate curing device to produce a sheet-like semi-finished product, the edge trimming and surface polishing processes are performed. As a result, it is manufactured into the final product. Such an acrylic resin artificial marble plate is made of a non-porous material having a uniform surface and inside, and is solid. It is easy to cut, grind, bend by heat, join with an adhesive, etc. The demand for building internal materials such as the upper plate of sinks, various counters, washing stands, and wall materials is increasing.

[0003] Usually, such acrylic resin artificial marble is commercially produced by two kinds of methods: a mold casting method (Cell Casting) and a continuous production method. The mold method is described in European Patent No. 66
951, EP 516299, EP 28
No. 5046, JP-A-52-36155 and JP-A-53-112990. The mold method is to use a resin gasket (Gask) on two metal plates or glass plates.
et), the mixture is poured into a mold crimped with a clamp (Clamp), and cured in a water bath or an air circulation oven for a first and second curing, and then the mold is dismantled to obtain a final product. However, since such a method is a batch type operation, the operation is complicated, the production cost is increased, and the productivity is very low. Therefore, there has been a demand for rationalization by continuous operation.

[0004] A continuous method of producing artificial marble, which makes the above-described mold method continuous, has not been directly disclosed in patent gazettes or the like, but a method of continuously casting an acrylic plate containing no inorganic substance. (US Patent 413386
No. 1 and Japanese Patent Publication No. 47-34815), which is a method known to be developed by Mitsubishi Rayon Co., Ltd. in Japan and applied to production. In this method, two sets of upper and lower endless steel belts (Endless St. Belt) running on the opposite surface in the same direction and at the same speed are used.
eel Belt), the polymerizable mixture is formed by the belt and gasket using a curing device consisting of a device that continuously supplies a resin gasket between both sides in the width direction of the belt and a suitable heating and cooling device. This is a method in which the product is continuously poured into a space, and is continuously polymerized according to the movement of the belt to take out a plate-like product from the outlet of the apparatus.

However, according to the above-mentioned method, since the upper belt of the opposed belts hangs down due to the weight of the belt itself, the product thickness in the width direction becomes non-uniform. In addition, proper hydraulic pressure must be maintained between the belt surfaces, which requires special equipment to be installed at the mixture injection part. In addition, the endless steel belt is bent between the lower belt supporting roll and the upper belt pressing roll of the facing belt.
g), it is difficult to prevent liquid leakage at the gasket sealing area, and the distance between the support and pressure rolls must be gradually reduced as the mixture hardens and the volume shrinks. . According to the above-described method, the manufacturing apparatus is complicated, the investment cost is increased, and it is difficult to reuse the resin gasket. As a result, operating costs increase. In addition, it is difficult to control the process, and there is a problem in that defective products having a defect in appearance such as a sink mark due to inclusion of air bubbles and shrinkage of the product upon curing are produced.

[0006] As an alternative for solving the problems of the continuous production method using two sets of endless steel belts as described above, there is a method of using one set of endless steel belts as a continuous curing device. When a curing device using a pair of endless steel belts is used as described above, it is easy to adjust the product thickness by using an appropriate raw material mixture supply device and a thickness adjusting device, and a rubber retainer is attached to the belt to mold the mold. It is easy to prevent the mixture from leaking during curing, and by attaching an appropriate synthetic resin film to the surface of the belt and the surface of the mixture, the product release from the belt is facilitated, and the volatilization of the polymerizable monomer is reduced. Can be prevented. Therefore, thickness deviation, cracks, air bubbles, sink marks (Sink M
ark) can be manufactured at a high productivity without a defect in appearance.

[0007] However, in general, when an artificial marble mixture containing an acrylic resin as a resin component is cured, a severe shrinkage of the resin component occurs. At the time of curing, both sides of the mixture are fixed with a metal plate or a glass plate (Cell Casting). Instead of using the method of crimping using two sets of upper and lower endless steel belts, when using a set of endless steel belts to cure, flattening like wood plywood due to the bending phenomenon during curing There is a problem that it is very difficult to obtain a natural artificial marble product.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the prior art, and has as its object to manufacture an acrylic resin artificial marble plate using a set of endless steel belts as a curing device. The mixture injected on a horizontal steel belt is subjected to two sets of upper and lower parts by using an appropriate curing device so that the curing reaction proceeds at the same speed on both the upper and lower surfaces of the mixture so as not to bend. Instead of using a set of endless steel belts to provide a method and apparatus for continuously producing an acrylic resin artificial marble plate capable of continuously producing an acrylic resin artificial marble at a high productivity without bending. is there.

[0009]

That is, according to one embodiment of the present invention, an acrylic resin artificial marble plate polymerization raw material mixture is converted into a continuous curing device comprising a set of endless steel belts and an auxiliary device. After continuously injecting and continuously hardening according to the movement of the steel belt to produce a plate-shaped semi-finished product, in producing an acrylic resin artificial marble plate through edge trimming and surface polishing processes,
It is divided into two or more areas, and each area has a blower, heater,
A curing chamber provided with a circulation duct and an air circulation device including a nozzle unit is symmetrically mounted on the upper and lower surfaces of a set of endless steel belts loaded with the raw material mixture, and the upper and lower surfaces of the polymerizable raw material are heated by hot air. And a method for continuously producing an acrylic resin artificial marble plate, characterized by heating and cooling the same.

According to another embodiment of the present invention, a driving pulley and an idle pulley circulate and are driven, and a mold and a retainer for preventing leakage of the raw material mixture during curing are mounted on an upper portion, and an operation is performed on the opposite surface. A set of endless steel belts to which a V-rope is attached to prevent meandering of the belt, a belt supporting roll for supporting the endless steel belt so that the endless steel belt does not drop, and a raw material for supplying a raw material mixture onto the endless steel belt. The mixture supply device, an upper film supply device for attaching a film to the upper portion of the raw material mixture, a lower film supply device for attaching a film to the surface of a steel belt, and an upper film supply device were connected. Thickness adjustment device to uniformly adjust the thickness of the raw material mixture in the width direction and endless steel belt In a continuous production apparatus for an acrylic resin artificial marble plate having a curing chamber divided into two or more sections provided in upper and lower sections, a blower, a heater, a circulation duct, an entrance damper, and a blower are provided in each section in the curing chamber. A high-temperature air circulation device consisting of a nozzle unit equipped with an outlet damper is installed, and the air coming out of the blower is heated by a heater, the air volume is adjusted by an inlet damper, and the mixture is loaded through a slit-type air nozzle. The mixture and the air that has been heat-exchanged with the belt are injected into the upper and lower portions of the belt so as to simultaneously heat and cool the upper and lower surfaces of the belt. A continuous production apparatus for acrylic resin artificial marble boards characterized by being configured to recover and circulate That.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings. When an acrylic resin artificial marble board is manufactured according to the present invention, acrylic syrup (Syru
p) 100 parts by weight, 110 to 300 parts by weight of an inorganic filler, and a small amount of a dispersing agent, a cross-linking agent, a light stabilizer, a curing initiator and a pigment are mixed in a stirring mixer, and degassed under vacuum. Manufactures acrylic resin artificial marble board raw material mixture. Next, the obtained mixture was subjected to a static mixer (St
At the same time, the curing initiator is charged and mixed at the same time, and then charged into the continuous curing device of the present invention.

The completely mixed acrylic resin artificial marble board raw material mixture passes through a raw material mixture supply device 5 and is continuously fed onto an endless steel belt 1 moving with a synthetic resin film for lower part attached to the surface. . A circular nozzle is attached to the raw material mixture supply device 5 to disperse the raw material mixture 14 so that the thickness becomes uniform in the width direction. While the supplied mixture moves with the endless steel belt 1, a synthetic resin film is attached to the surface,
After the thickness is made constant in the width direction by the thickness adjusting device 6 as shown in FIG. 2, it is transferred into the curing chambers 7, 8, 9, and 10. Here, the purpose of sticking a film on the surface of the endless steel belt 1 and the raw material mixture 14 is as follows.
This is because after the curing is completed, the product is easily separated from the belt surface at the outlet of the device, and the volatilization of the monomer component in the raw material mixture during the curing is prevented. In the present invention, as the material of the upper and lower films, polyethylene, nylon, polypropylene,
Vinylon or the like can be used, and vinylon is preferred in terms of mold releasability and prevention of wrinkle formation on the product surface.

[0013] The continuous curing device of the present invention comprises a set of endless steel belts and ancillary devices. Endless steel belt 1 has rubber retainer 15 and V-rope (V-
Rope) 16 is mounted, and a driving pulley 2 ′ and an idle pulley 2 driven by the driving motor 12 are provided.
Circulating drive to provide the required tensile force. The curing chamber is divided into two or more sections, and in the illustrated embodiment, divided into four sections of curing chambers 7, 8, 9, and 10, each section heating and cooling the endless steel belt and the raw material mixture. High-temperature air circulation device is installed. The air circulation device is a blower 21, a heater 2
3, circulation ducts 22, 26, nozzle units 11, 1
1 (the blower 21, the heater 23, the circulation duct 22, and the circulation duct 26, which are shown on the front side of the drawing in FIG. 1, are omitted), and the nozzle units 11, 11 ' , A slit-type air nozzle, a blast air circulation inlet, and an air outlet. The upper and lower portions of the endless steel belt 1 on which the mixture is loaded are symmetrically provided at regular intervals on the belt surface for heating and cooling. And inlet and outlet dampers 24 and 24 'and outlet dampers 25 and 25' for adjusting the air volume at the outlet and the inlet, respectively.
Is attached. The raw material mixture is cooled to such an extent that the curing reaction is completed while passing through the curing chamber and does not deform in the subsequent process, and then discharged to the outlet of the apparatus. Finally, the hardened and cooled artificial marble in the hardening chambers 7 to 10 is cooled to room temperature by a separate cooling device, cut into required dimensions by a cutting device, and subjected to edge trimming and surface polishing processes. Processed into final artificial marble board product.

Next, an apparatus for continuously producing an acrylic resin artificial marble plate of the present invention will be described in detail. FIG. 1 shows an apparatus for continuously producing an acrylic resin artificial marble plate using a set of endless steel belts of the present invention. In the apparatus of the present invention, the endless steel belt 1 is generally made of steel or stainless steel and has a thickness of 0.1 to 3 mm.
mm is preferred, and more preferably 0.5 to 2 mm.

FIG. 2 is a schematic longitudinal sectional front view showing an endless steel belt portion on which a raw material mixture is loaded in the continuous production apparatus for an acrylic resin marble plate of the present invention. As shown in FIG. 2, a trapezoidal retainer 1 made of a rubber material is generally provided on the upper surface of the endless steel belt 1 in order to prevent the mixture from leaking to both sides during molding and curing.
5 is attached, and a V-Rope 16 made of a rubber material is attached to the opposite surface to prevent meandering of the belt during operation. The set of endless steel belts 1 is moved by driving a driving pulley 2 ′ at a constant speed by a driving motor 12, and a pulling force is given by an idle pulley 2 provided with a tension adjusting device, and the belt supporting rolls 13, 13 'prevents sagging and ensures the required flatness. At this time, the tensile force is preferably as high as possible on the flatness maintaining surface of the belt, but is generally 3 to 5 kg / mm ² .

FIGS. 3 to 6 are detailed views of a curing chamber and an air circulation heating and cooling apparatus in the apparatus for manufacturing an acrylic resin artificial marble plate of the present invention. FIGS. 7 and 8 are FIGS. FIG. 6 is a detailed view of a nozzle unit in the air circulation heating and cooling device of No. 6; When using two sets of endless steel belts, using a hot water injection type heating device as a heating device is advantageous in terms of heat transfer effect, but when using one set of endless steel belts as in the present invention. This method is not applicable because heating the upper surface of the mixture is not possible. Therefore, in the present invention, an air circulation heating and cooling system using hot air is used as the heat source supply device.

The curing chambers 7, 8, 9, and 10 of the present invention are divided into a heating section and a cooling section according to their roles. Each section is divided into one or more sections, and each section has a blower 21, a circulation duct 22, 2 as shown in FIGS.
6, and an air circulation device composed of nozzle units 11 and 11 '. Nozzle units 11, 11 '
Are the air inlets 17, 1 as shown in FIGS.
7 ', slit type air nozzles 18, 18', blast air circulation inlets 19, 19 ', air outlets 20, 20', inlet dampers 24, 24 'and outlet dampers 25 for air flow control,
25 ', which are symmetrically arranged above and below the belt so as to simultaneously heat and cool the upper and lower surfaces of the belt on which the mixture is loaded.

The distance between the endless steel belt 1 and the slit type air nozzles 18, 18 'is 30 to 100 mm.
Is set in the range. FIG. 7 is a longitudinal sectional view of a nozzle unit portion in the apparatus according to the present invention (however, illustration of the endless steel belt 1 is omitted for convenience of explanation), and FIG. 8 is a transverse sectional view of the nozzle unit portion. The width W of the slit-type air nozzles 18 and 18 ′ in the direction perpendicular to the belt traveling direction is 90% or more of the width of the molded mixture, and the interval width t of the slits in the belt traveling direction is 1 to 1.
The distance L in the belt traveling direction between one slit and an adjacent slit is 100 to 300 mm.
Is preferred. The capacity of the blower 21 is selected so that the maximum jetting speed is 5 m / sec at the slit type air nozzles 18 and 18 '.

The air discharged from the blower 21 is heated to a set temperature by a heater 23, and the heated hot air is supplied to an entrance damper 2a.
The air volume is adjusted by 4, 24 'and the slit air nozzle 1
The air which has been injected into the upper and lower portions of the belt loaded with the mixture through 8, 18 'and exchanges heat with the mixture and the belt is supplied to the air circulation inlets 19, 19' and the air outlets 20, 2.
0 ′, and is collected and circulated to the blower 21 through the outlet dampers 25 and 25 ′. Although the number of sections in the heating section can be one, it is preferable that the number of sections is about two in terms of temperature control and bending prevention, and the lengths of the sections are preferably substantially the same. The temperature of the circulating air may be the same in the entire section, or may be gradually increased in each section. In this section, heat is supplied to the mixture to accelerate and progress the polymerization reaction, and about 90-95% of the whole reaction is performed.

In the apparatus of the present invention, the temperature of the heating section varies depending on the curing agent used, but is preferably in the range of 60 to 80 ° C.
If the temperature of the heating section is less than 60 ° C., it is not preferable in terms of accelerating the curing. Conversely, if it exceeds 80 ° C., the temperature of the mixture is reduced to the boiling point of methyl methacrylate (MMA) before the curing is sufficiently performed. When the temperature exceeds 100 ° C., pores are generated inside the product or the surface becomes defective. The essential items required to prevent the product from bending during the heating section are that the polymerization reaction must be performed on the upper and lower surfaces of the mixture at the same polymerization rate, and that the polymerization reaction also occurs in the width direction at the same polymerization rate. That is what must be done. That is,
If the polymerization reaction on the upper surface is fast, the central portion rises up as compared to the edge in the width direction, and if the polymerization reaction on the lower surface is fast, the central portion is deflected downward so that the polymerization speed is reduced. Deflection occurs even if the directions are not the same.

Therefore, according to the present invention, by controlling the heat transfer efficiency by adjusting the jet velocity of the air circulating at the same temperature in each zone, the degree of polymerization progress on the upper and lower surfaces of the raw material mixture is adjusted to be the same, and the nozzle unit is used. By producing and installing the slit so that the width of the slit is 90% or more of the width of the product, the polymerization reaction proceeds to the same extent in the width direction, thereby preventing the occurrence of bending. In the acrylic resin artificial marble plate continuous manufacturing apparatus of the present invention, the upper portion of the raw material mixture directly contacts the mixture through the upper film and the lower portion conducts heat through the endless steel belt. Different, for example, 1.0 mm thick
In the case of the stainless steel belt, the lower flow rate (flow rate) is 0.5 m / s, and the upper flow rate (flow rate) is adjusted to 20 to 50% of the lower flow rate. The flow velocity at the bottom is 0.
If it is less than 5 m / s, the performance as a heating and cooling device cannot be exhibited. In addition, unlike the method described above, using two blowers and heaters for each area, a method in which the temperature of the air circulating up and down the belt is different, for example, raising the lower temperature by about 5 to 20 ° C. A method of adjusting the jet wind speed is also possible, but such a method requires only a complicated device,
There are disadvantages that are not practical.

Next is a heat treatment section (normal cooling section).
In this section, the polymerization reaction is completed and cooled. Such a heat treatment section is also possible from one section, but two sections are preferable in terms of temperature control and deflection prevention, and the length of each section is preferably the same. Preferably, they are the same. In addition, a circulating heating device as in the heating section is installed. 90-95 in heating section
% Of the raw material mixture reached the maximum exothermic temperature in this section (about 110 to 130 ° C.), and gradually cooled to around the glass transition temperature (105 to 110 ° C.) while reaching the outlet.
The reaction is completed and cooled while being aged, and no deformation occurs even in the subsequent cooling process to room temperature by a separate device. The circulating air temperature in the heat treatment section is preferably 90 to 105 ° C,
In the whole section, it is reduced uniformly or step by step.
If the temperature of the heat treatment section is lower than 90 ° C., the cured product may be rapidly cooled after reaching the maximum heat generation temperature and may be bent, or the curing reaction may not be completed.
If the temperature exceeds 5 ° C., the cured product is not sufficiently cooled and does not completely solidify at the outlet of the device, and the possibility of bending during the subsequent cooling process to room temperature by a separate device increases.

In the heat treatment section, if the temperature of the upper and lower surfaces of the cured product is not properly adjusted, bending occurs. In other words, the effect is not only large by the curing shrinkage, but if the upper surface of the cured product is cooled quickly by the effect of cooling shrinkage, the center of the width is recessed downward,
If the lower surface is cooled quickly, a bend occurs such that the central portion rises upward. Therefore, the cooling rates of the upper and lower surfaces of the cured product must be adjusted in the same manner. In the present invention, the cooling rate is adjusted in the same manner as in the heating section. Up·
The lower flow rate (flow rate) is adjusted the same as in the heating section. That is,
The wind speed of air circulated and injected at the same temperature is set higher at the lower surface of the belt than at the upper surface of the mixture to increase the heat transfer efficiency of the lower surface, and the upper and lower surfaces of the cured product are cooled equally, preventing bending Is done. On the other hand, by adjusting the cooling rate of the upper and lower surfaces of the cured product to be the same, the temperature of the air circulating above and below the belt by using two blowers and heaters for each area in a manner to prevent bending is different, For example, a method of lowering the temperature of the lower portion of the belt by about 5 to 10 ° C. and adjusting the jet air velocity can be used, but according to such a method, only the apparatus becomes complicated and is not practical.

The acrylic resin artificial marble mixture applied in the practice of the method according to the present invention has the following composition. Acrylic resin is methyl methacrylate (MM
A) Alkyl acrylate (C ₁ -C ₈ ) ester which can be used alone or copolymerizable therewith, alkyl methacrylate (C
₂ -C ₈₎ esters, styrene, and a halogen or alkyl (C ₁ ~C ₂₎ derivatives of styrene is obtained by mixing up to 30 wt%. Such an acrylic resin component is partially polymerized in a continuous or batch reactor for process compatibility, or polymethyl methacrylate (PMM).
A) is dissolved in methyl methacrylate (MMA) to prepare and use an acrylic syrup having a polymer content in the range of 10 to 35% by weight.

Examples of the filler of the raw material mixture include inorganic fillers such as calcium carbonate, alumina, glass fiber, aluminum hydroxide, silica, talc, magnesium hydroxide, calcium hydroxide, and the like, and particles formed by crushing artificial stone. It contains a marble chip and the like, and is used in an amount of 110 to 300 parts by weight based on 100 parts by weight of the acrylic resin component. If the amount of such an inorganic filler is less than 110 parts by weight with respect to 100 parts by weight of the acrylic resin component, sink marks, bubbles and the like are generated, and the occurrence of bending becomes large. If the amount exceeds the above range, the transparency and mechanical properties of the artificial marble will decrease, and the artificial marble will be unsuitable.

The acrylic resin artificial marble mixture used in the practice of the method according to the present invention may be used as a process preparation and an additive for improving physical properties, if necessary, within a range that does not significantly impair the curing rate, as long as it does not significantly inhibit the curing rate. Light stabilizers, crosslinking agents and the like can be added in small amounts. As the curing agent of the present invention, any redox type initiator using a heat decomposition type radical initiator or an accelerator may be used. Preferably, a compound having a 10-hour half-life temperature of 70 ° C. or less is used alone. Or a 10 hour half-life temperature of 70 ° C
Combine the following with the above and use a plurality of them. Hereinafter, the present invention will be described more specifically with reference to examples. However, the following examples are for the purpose of explanation only, and the present invention is not limited to the following examples. Compositions are by weight unless otherwise specified.

First Example 25 parts by weight of a polymethyl methacrylate (PMMA: LG Chemical) resin having a weight average molecular weight of 100,000 was added to methyl methacrylate (MMA: Mitsubishi Rayo).
n Co.) 100 parts by weight of acrylic syrup prepared by dissolving in 75 parts by weight, 200 parts by weight of aluminum hydroxide having an average particle diameter of 30 μm (Showa Denko KK H-210), dispersant (B
YK-Chemie GmbH W960) 1 part by weight, crosslinking agent (ethylene glycol dimethacrylic resin: Sartomer Co. SR)
-231) 1 part by weight, light stabilizer (Cyansorb U, Cyanamid)
V-2098) 0.5 part by weight, a curing initiator (lauroyl peroxide: Nippon Yushi peroyl L) 0.5 part by weight, and a pigment (Cl
ba Gelgy) was mixed in a stirrer mixer, degassed under vacuum, and a mixture having a viscosity of about 5,000 Cps was continuously fed to a static mixer at 6.0 kg / min by a metering pump. The mixture was charged, and at the same time, a curing initiator (t-butylperoxy neodecanoate: Seiki Chemical Co., Ltd.) was charged at a rate of 10 g / min, mixed, and then charged into the continuous curing apparatus shown in FIG.

In the continuous hardening apparatus composed of a set of endless steel belt and ancillary equipment used in the present embodiment, the endless steel belt 1 is made of stainless steel to have a width of 1.0 m and a thickness of 0.8 mm. It was constructed so that the rubber retainer 15 and the V-rope 16 were attached and driven by the driving pulley 2 ′ and the idle pulley 2 to provide a necessary tensile force. At this time, the distance between the centers of the pulleys is 15 m, the total length of the curing chamber is 12 m, and each of the two sections of the heating section and the four sections of the two cooling sections divided into the 3 m length by the heat insulating structural material.
It consisted of two areas. Each area has a blower 21 (80m
³ / min), electric heater 23 (15Kw), circulation duct 2
2 and 26, a high-temperature air circulation device of the same standard composed of the nozzle units 11 and 11 'was installed. The nozzle units 11 and 11 'are 800 mm wide, 600 mm high, and 2.
8 m, a hexahedron shape, the distance L between the slit type nozzles is 200 mm, the interval t between the slits is 2 mm,
An outlet damper 25, 25 'for adjusting the air volume and an inlet damper 24, 24' are provided at the outlet and the entrance,
In order to heat and cool the upper and lower portions of the endless steel belt 1 on which the mixture was loaded, the endless steel belt 1 was symmetrically installed at intervals of 60 mm on the belt surface.

As the operating conditions of the continuous manufacturing apparatus, the linear velocity of the belt is 0.3 m / min, the air temperature at the heater outlet in each section is 70 ° C., 85 ° C., 100 ° C., 95 ° C.
In each zone, the temperature supplied to the nozzle units provided on the upper and lower portions of the belt was the same. The jet wind speed at the slit nozzle in each section was set differently as shown in Table 1 below for each example.

The mixture supplied to the continuous curing device is supplied to the raw material mixture supply device 5 by a lower film supply device 3 on which a vinylon film is adhered on the surface and moves.
Is cast to a uniform thickness in the width direction, then a vinylon film is also attached to the upper surface of the raw material mixture by the upper film supply device 4, and the thickness is uniformly adjusted in the width direction by the thickness adjustment device 6. After the curing chamber 7-10
And cured and cooled. In this process, the highest heat generation temperature is 123 to 127 near the middle of the first section of the cooling section.
° C and at the exit of the curing chamber the temperature of the cured product is 103
１０７107 ° C. Next, after the continuous curing device, the mixture was cooled to room temperature by a separate cooling device to obtain an acrylic resin artificial marble cured product having a width of 800 mm and a thickness of 15 mm. The surface hardness (Rockwell M Scale) of the hardened artificial marble obtained was 9
3. The flexural hardness was 650 kg / cm ² (ASTM790), and even if it was immersed in boiling water for 1 hour, there was no whitening phenomenon and the required properties of artificial marble were satisfied. Further, there were no appearance defects such as cracks, bubbles, and sink marks, and no bending occurred, so that it was suitable for subsequent edge trimming and surface polishing.

Second Example A syrup produced by dissolving 25 parts by weight of a polymethyl methacrylate (PMMA: LG Chemical) resin having a medium average molecular weight of 100,000 in 75 parts by weight of methyl methacrylate (MMA: Mitsubishi Rayon Co.) 90 parts by weight of ethyl acrylate (Mitsubishi Rayon Co.) mixed with 10 parts by weight of 100 parts by weight of acrylic syrup, 150 parts by weight of aluminum hydroxide (Showa Denko KK H-210) having an average particle size of 30 μm, dispersant (BYK -W960 manufactured by Chemie GmbH) 1.0 part by weight,
Crosslinking agent (Ethylene glycol dimethacrylate: Sartom)
er Co. SR-231) 1.0 part by weight, light stabilizer (Cyanami
d company Cyasorb UV-2098) 0.5 parts by weight and pigment (C
lba-Gelgy) was mixed in a stirring mixer, and the mixture having a viscosity of about 4,500 Cps produced by degassing under vacuum was continuously fed to a stationary hardener mixer at 8.0 kg / min by a metering pump. And at the same time, a curing initiator (bis (4-tbutylcyclohexyl) peroxydecarboxylate (chemical AKZO)
(25% toluene solution) was added at 10 g / min and mixed, and then charged into the continuous curing apparatus of the first example.

The operating conditions of the continuous curing device were as follows: the linear velocity of the belt was 0.4 m / min, the air temperature at the heater outlet in each section was 60 ° C., 75 ° C., 100 ° C., and 97 ° C. An artificial marble having a width of 800 mm and a thickness of 15 mm was manufactured under the same conditions and method as in the first embodiment, except that the jet air velocity was changed by the nozzle as shown in Table 1 below. It was measured. During the hardening and cooling processes, the highest exothermic temperature appears near the middle of the first section of the cooling section (118).
~ 122 ° C), and the temperature of the cured product at the outlet of the device is 103
１０７107 ° C. The surface hardness of the obtained cured product (Ro
ckwell M Scale) is 92, flexural hardness (ASTM790) is 64
It was 0 kg / cm ² , and even if it was immersed in boiling water for 1 hour, the whitening phenomenon did not appear and the required physical properties of artificial marble were satisfied. In addition, there were no appearance defects such as cracks, bubbles, and sink marks, and there was no bending, which was suitable for subsequent edge trimming and surface polishing.

First and Second Comparative Examples The same aluminum hydroxide (Showa Denko H-210) was used in 100 parts by weight of the acrylic syrup of the first example.
Parts by weight, dispersant (W960, manufactured by BYK-Chemie GmbH) 0.7
Parts by weight, 1.2 parts by weight of a crosslinking agent (ethylene glycol dimethacrylate: Sartomer Co. SR-231), 0.5 parts by weight of a light stabilizer (Cyasorb UV-2098 from Cyanamid),
High temperature initiator (Lauroyl peroxide: Nippon Yushi peroyl L)
0.5 parts by weight and a pigment (manufactured by Clba-Gelgy) were mixed with a stirrer mixer and degassed under vacuum.
6. Mix the 00 Cps mixture into a static mixer with a metering pump.
0 kg / min was continuously charged, and at the same time, a low-temperature initiator (t-butylperoxyneodecanoate: Seiki Chemical Co., Ltd.) was charged at a rate of 10 g / min, mixed, and then continuously cured in the first example. The artificial marble hardened material was manufactured by the same method as in the first embodiment except that the injection wind speed in each area was changed as shown in Table 1 below by introducing the device into the apparatus, and the physical properties thereof were measured. It was measured. Compared to the first and second embodiments, a sync mark was generated and severe bending occurred, which made it difficult to commercialize the product.
The results of the above Examples and Comparative Examples are shown together in Table 1 below.

[0034]

[Table 1]

[0035]

As described above, the method and the apparatus for continuously producing an acrylic resin artificial marble plate of the present invention described above use air by circulating them. The width of the slit nozzle is the same or similar to that of the product, so that the polymerization reaction and cooling proceed in the same direction in the width direction. This has the advantage of preventing occurrence. Also, by adjusting the amount of air (air velocity) supplied to the nozzle unit, the curing reaction proceeds at the same speed on the upper and lower surfaces of the mixture loaded on the endless steel belt, and gradually decreases after reaching the maximum heat generation temperature. There is an advantage that even if a set of endless steel belts are used, the artificial marble can be continuously produced without bending even if the upper and lower surfaces of the cured product are cooled so that the temperatures of the upper and lower surfaces of the cured product become the same in the cooling process. Therefore, the method and apparatus of the present invention have a simpler apparatus configuration than the method using two sets of endless steel belt hardening apparatuses in the continuous production of an acrylic resin artificial marble plate, and consumables such as a synthetic resin gasket. It is possible to manufacture a high quality acrylic resin artificial marble plate which is free from bending, cracks, bubbles, sink marks and other appearance defects.

[Brief description of the drawings]

FIG. 1 is a schematic vertical sectional side view of an apparatus for continuously manufacturing an acrylic resin artificial marble plate using a set of endless steel belts according to the present invention.

FIG. 2 shows an apparatus for continuously producing an artificial marble plate according to the present invention.
FIG. 3 is an enlarged vertical sectional front view showing an endless steel belt portion on which a raw material mixture is loaded.

FIG. 3 shows an apparatus for continuously producing an artificial marble plate according to the present invention.
FIG. 2 is an enlarged longitudinal sectional side view of a curing chamber and an air circulation heating and cooling device.

FIG. 4 shows an apparatus for continuously producing an artificial marble plate according to the present invention.
FIG. 3 is an enlarged cross-sectional plan view of the curing chamber and the air circulation heating and cooling device.

FIG. 5 is a vertical sectional front view taken along the line BB of FIG. 4;

FIG. 6 is a vertical sectional front view taken along line AA in FIG. 4;

FIG. 7 shows an apparatus for continuously producing an artificial marble plate according to the present invention.
FIG. 4 is an enlarged vertical sectional side view of a nose unit unit of the heating and cooling device.

FIG. 8 is a transverse sectional view taken along line CC in FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Endless steel belt 2 Idle pulley 2 'Drive pulley 3 Lower film supply device 4 Upper film supply device 5 Raw material mixture supply device 6 Thickness adjustment device 7 to 10 Curing chamber 11, 11' Nozzle unit 12 Drive motor 13, 13 'Belt support roll 14 Raw material mixture 15 Retainer 16 V rope 17, 17' Air inlet 18, 18 'Slit nozzle 19, 19' Air circulation inlet 20, 20 'Air outlet 21 Blower 22 Circulation duct 23 Heater 24, 24 'inlet damper 25, 25' outlet damper 26 circulation duct t interval between slits L interval between slits w nozzle width

──────────────────────────────────────────────────の Continued on front page (51) Int.Cl. ⁶ Identification code FI C04B 111: 54

Claims (5)

[Claims] 1. An acrylic resin artificial marble board polymerization raw material mixture is continuously injected into a continuous curing device comprising a set of endless steel belts and an auxiliary device, and is continuously cured in accordance with the movement of the steel belt. After manufacturing a plate-shaped semi-finished product, it is divided into two or more sections in the manufacture of acrylic resin artificial marble board through edge trimming and surface polishing processes, and each section has a blower, heater, circulation duct, nozzle A curing chamber provided with an air circulation device consisting of units is symmetrically installed on the upper and lower surfaces of a set of endless steel belts loaded with the raw material mixture, and the upper and lower surfaces of the polymerizable raw material are heated by hot air in the same manner. And a method for continuously producing an acrylic resin artificial marble plate. 2. An acrylic resin artificial marble plate polymerization raw material mixture is a mixture of an acrylic resin and a filler, wherein the acrylic resin is a methyl methacrylate resin alone or an alkyl acrylate copolymerizable therewith. (C
₁ -C ₈₎ esters, alkyl methacrylate (C ₂ ~C ₈₎
Ester styrene, styrene halogen or alkyl (C ₁ -C ₂ ) derivatives are mixed up to 30% by weight, and the filler of the raw material mixture is calcium carbonate, alumina, glass fiber, aluminum hydroxide, silica talc, Including inorganic fillers such as magnesium hydroxide and calcium hydroxide and particle-shaped marble chips produced by crushing artificial stone, 1 to 100 parts by weight of acrylic resin component
The method for continuously producing an acrylic resin artificial marble plate according to claim 1, wherein 10 to 300 parts by weight is added. 3. A set of endless steel belts circulatingly driven by a driving pulley and an idle pulley, a belt supporting roll for supporting the endless steel belt so as not to drop, and a raw material mixture for supplying the raw material mixture onto the steel belt Feeder, Upper film feeder for sticking film on top of raw material mixture, Lower film feeder for sticking film on the surface of steel belt, Raw material connected to upper film feeder A series of acrylic resin artificial marble plates provided with a thickness adjusting device for uniformly adjusting the thickness of the mixture in the width direction and a curing chamber divided into two or more sections provided at the upper and lower portions of an endless steel belt. In the manufacturing apparatus, a blower, a heater, a circulation duct, A high-temperature air circulation device consisting of a nozzle unit equipped with a damper and an outlet damper is installed, and the air coming out of the blower is heated by a heater, the air volume is adjusted by an inlet damper, and the mixture is loaded through a slit-type air nozzle. The mixture and the air that has been heat-exchanged with the belt are heated and cooled at the same time by heating and cooling the upper and lower surfaces of the belt at the same time. A continuous apparatus for producing an acrylic resin artificial marble plate, wherein the apparatus is configured to recover and circulate, and the raw material mixture is heated and cooled by hot air. 4. A set of molds and a retainer for preventing leakage of the raw material mixture during curing are mounted on an upper portion of the pair of endless steel belts, and a V for preventing belt meandering during operation is mounted on the opposite surface. The continuous production apparatus for an acrylic resin artificial marble plate according to claim 3, wherein a rope is attached. 5. The distance between the endless steel belt and the slit type nozzle is 30 to 100 mm, the opening width (t) of the slit of the nozzle unit in the belt traveling direction is 1 to 5 mm, The width (W) in the direction perpendicular to the direction is 90% or more of the width of the molded mixture, and the distance (L) between one slit and an adjacent slit in the belt traveling direction is 100 mm or more.
4. The apparatus for continuously producing an acrylic resin artificial marble plate according to claim 3, wherein the thickness is 300 mm.