JP2001011274A - Production of acrylic bmc, and acrylic artificial marble - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an acrylic BMC stably at a high production efficiency and enable an acrylic artificial marble free of irregular color and excellent in external appearance to be obtained by using an acrylic monomer, an acrylic polymer, and an inorganic filler as the constituents and by feeding powder components of the constituents uniformly into a continuous twin-screw kneader. SOLUTION: An acrylic monomer (A) in an amount of 5-95 mass %, an acrylic polymer (B), preferably a powdery polymer having an average particle size of 1-500 μm, in an amount of 0.1-30 mass %, and an inorganic filler (C) in an amount of 5-95 mass % are used as the constituents. The constituents are fed into a twin-screw kneader while the feeding accuracy of the powdery constituents is being maintained in a range of ±7 mass %; based on the specified feeding amount in 5 sec, and are then kneaded for 3 min, giving an acrylic BMC. Preferably, the powdery constituents are fed into the continuous twin- screw kneader with a continuous supply machine, such as a screw feeder, a vibration feeder, or a belt feeder. The resultant BMC is thermally cured under pressure to give an artificial marble, of which the color difference measured at three points or more is 3.0 or lower.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an acrylic BMC (bulk molding compound) having high productivity, excellent handleability, moldability, and storage stability.

[0002]

2. Description of the Related Art Acrylic artificial marble in which an inorganic filler such as aluminum hydroxide is blended with an acrylic resin has various excellent functional properties such as excellent molded appearance, warm touch and weather resistance. It is widely used for counters such as kitchen counters, vanities, waterproof pans, and other architectural uses. These are generally filled in a mold with a so-called premix in which an inorganic filler is dispersed in an acrylic syrup composed of an acrylic monomer and an acrylic polymer having methyl methacrylate as a main component. It is manufactured by a casting method that cures and polymerizes at low temperatures. However, since the acrylic syrup has a low boiling point, the curing temperature has to be lowered, and as a result, a long molding time is required, resulting in low productivity. In addition, the shape of the molded product is limited due to a problem in the filling property of the premix into the mold.

[0003] In order to improve these drawbacks, studies have been made to produce an acrylic artificial marble by heating and pressurizing an acrylic BMC obtained by thickening an acrylic premix with a thickener. I have. JP-A-10-218905, JP-A-10-21891
No. 1 or JP-A-10-67906 discloses a continuous supply step of an acrylic monomer and an acrylic polymer to a continuous twin-screw kneading step, and a method for producing an acrylic BMC by the kneading step. Is disclosed. However, in the methods described in these publications, the description regarding the supply mass accuracy of the material constituent components is not specified, and in particular, depending on the properties and charging method of the powder components, the charging speed, When the supply accuracy is deteriorated and the continuous production described in these publications is continued for a long time, a portion where the component mass ratio in the obtained acrylic BMC is not constant occurs locally, and this acrylic BM
When C was cured, there was a problem that an acrylic artificial marble having color spots was obtained.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention utilizes the above-mentioned manufacturing method (Japanese Patent Laid-Open No. 10-67906) discovered by the present inventors. It has been made to further improve the conditions and the like. That is, the object of the present invention is a simple production line,
An object of the present invention is to find a method for continuously producing an acrylic BMC having excellent production efficiency. In particular, an acrylic BMC capable of obtaining an acrylic artificial marble having excellent appearance without color spots.
For stable continuous production over a long period of time, and an acrylic artificial marble having a color difference of 1.0 or less.

[0005]

Means for Solving the Problems The inventors of the present invention have studied to achieve the above object, and as a result, by improving the supply accuracy of the powder component among the constituent components of the acrylic BMC, a continuous twin-screw system has been developed. Can be performed in a kneader, and can be used to simplify the production line.
The present inventors have found that an acrylic BMC exhibiting a good appearance can be produced with high production efficiency, and completed the present invention.

That is, the present invention relates to a method for producing an acrylic BMC comprising an acrylic monomer (A), an acrylic polymer (B), and an inorganic filler (C) as constituents. Among the components, a method for producing an acrylic BMC in which a powder component is supplied to a continuous twin-screw kneader within a range of ± 7% by mass with respect to a predetermined supply amount for 5 seconds, and an acrylic system obtained by the continuous production method Colorimetric values (L) measured at three or more arbitrary positions obtained by curing BMC under heat and pressure
^* , A ^* , b ^* ), the color difference between each colorimetric point (△)
E ^*) maximum value (△ ^E * MAX) is in the provision of 3.0 or less of acrylic artificial marble.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below.

The acrylic monomer (A) used in the present invention is a component that imparts appropriate fluidity when shaping the acrylic BMC according to the present invention. The content of the component (A) is not particularly limited, but is preferably in the range of 5 to 95% by mass based on the total amount of the acrylic BMC in the present invention. When the content is 5% by mass or more, acrylic B
The fluidity during shaping of MC tends to be good,
When the content is 95% by mass or less, the obtained acrylic BMC tends to have a low shrinkage ratio during curing. The lower limit of the content is more preferably 10% by mass or more, and 15% by mass or more.
Particularly preferred is at least mass%. About the upper limit of this content, 50 mass% or less is more preferable, and 40 mass% or less is especially preferable.

The acrylic monomer used in the component (A) is a monomer having a methacryloyl and / or acryloyl group or a mixture thereof, and is not particularly limited.

As a specific example, for example, methyl (meth)
Ester group having an aromatic ring such as acrylate, alkyl (meth) acrylate having an alkyl group having 2 to 20 carbon atoms, hydroxyalkyl (meth) acrylate having a hydroxyalkyl group having 1 to 20 carbon atoms, and benzyl (meth) acrylate (Meth) acrylates having an ester group having a cyclohexane ring, such as (meth) acrylates and cyclohexyl (meth) acrylates, and (meth) acrylates having an ester group having a bicyclo ring, such as isobornyl (meth) acrylate, tricyclo [5] [2.1.0 ^2,6 ] (meth) acrylate having an ester group having a tricyclo ring, such as decanyl (meth) acrylate, 2,2,2-trifluoroethyl (meth)
(Meth) acrylate having an ester group having a cyclic ether structure such as (meth) acrylate having an ester group having a fluorine atom such as acrylate, glycidyl methacrylate, and tetrahydrofurfuryl (meth) acrylate; (meth) acrylic acid; ) Acrylic monofunctional monomers such as metal acrylates and (meth) acrylic amides; and ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, and polypropylene Glycol di (meth) acrylate, 1,
3-butylene glycol di (meth) acrylate, 1,
4-butylene glycol di (meth) acrylate, polybutylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) Acrylate, 1,10-decanediol di (meth) acrylate, dimethylolethanedi (meth) acrylate, 1,1-dimethylolpropanedi (meth) acrylate, 2,2-dimethylolpropanedi (meth) acrylate, triacrylate Methylolethanetri (meth) acrylate, trimethylolpropanetri (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolmethanedi (meth) acrylate, and (meth) acrylic acid and a polyhydric alcohol [for example, Data erythritol, multivalent esters of dipentaerythritol, etc.], an acrylic polyfunctional monomer such as allyl (meth) acrylate.

These can be used alone or in combination of two or more if necessary. In addition, in this specification, "(meth) acrylate" means "acrylate and / or methacrylate."

In particular, a molded article obtained by using an acrylic BMC containing methyl methacrylate in the component (A) tends to have a depth unique to marble, and tends to have a good appearance. ,preferable. The content of methyl methacrylate is not particularly limited, but is preferably in the range of 1 to 40% by mass in the total amount of the acrylic BMC in the present invention. The lower limit of the content is more preferably 5% by mass or more, and the upper limit is more preferably 30% by mass or less.

The component (A) includes, in addition to the acrylic monomer, aromatic vinyl such as styrene and divinylbenzene, vinyl acetate, (meth) acrylonitrile, vinyl chloride, maleic anhydride, maleic acid, and maleic acid. It may contain monomers such as esters, fumaric acid, fumaric acid esters, and triaryl isocyanurates.

Acrylic B obtained by the production method of the present invention
In order to impart properties such as heat resistance, hot water resistance, strength, solvent resistance and dimensional stability to molded products obtained using MC,
It is preferable to include a polyfunctional monomer in the component (A). In this case, the content of the polyfunctional monomer is not particularly limited, but is preferably in the range of 1 to 30% by mass based on the total amount of the acrylic BMC in order to obtain the above effect more effectively. The lower limit of the content is more preferably 3% by mass or more, and the upper limit is more preferably 25% by mass or less.

[0015] In particular, at least one of neopentyl glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate and tripropylene glycol di (meth) acrylate as the polyfunctional monomer.
The use of seeds is preferable because a molded article having extremely excellent surface gloss and hot water resistance can be obtained. In this case, at least one of neopentyl glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, and tripropylene glycol di (meth) acrylate is used in combination with another polyfunctional monomer. Is also good.

The acrylic polymer (B) used in the present invention is a thickener component which thickens the acrylic BMC to a sticky (bulk-like) material having good tackiness without stickiness. After absorbing the monomer (A), at least a part of the acrylic polymer (B) is dissolved to increase the viscosity of the entire system, thereby acting as a thickener. As the constituent components of the acrylic polymer (B) (monomers used for the polymerization), the monofunctional monomers and / or polyfunctional monomers listed for the acrylic monomer (A) described above are used. A polymer can be used, and if necessary, a homopolymer polymerized alone may be used, or a copolymer using two or more kinds may be used.

The form of the acrylic polymer (B) is not particularly limited, but is preferably a polymer powder. When the acrylic polymer (B) is a polymer powder, its handleability tends to be good, and the dissolution rate in the acrylic monomer (A) increases, and the viscosity increasing rate decreases. It tends to be faster, thickening is possible in a short time, and the productivity of acrylic BMC tends to be improved. When the acrylic polymer (B) is a powder, the average particle size of the polymer powder is not particularly limited, but is preferably in the range of 1 to 500 μm. When the average particle size is 1 μm or more, the polymer powder is less likely to be scattered, and the handleability of the polymer powder tends to be better.
When it is less than m, the appearance of the resulting molded article, particularly gloss and surface smoothness, tend to be good. The lower limit of the average particle size is more preferably 5 μm or more, and
m or more is particularly preferred. The upper limit is 35
0 μm or less is more preferable, and 200 μm or less is particularly preferable.

The polymer powder may be a non-crosslinked polymer powder or a crosslinked polymer powder, but is preferably a non-crosslinked polymer powder. When the polymer powder is a non-crosslinked polymer powder, the thickening rate tends to increase, the thickening can be performed in a short time, and the productivity of acrylic BMC tends to improve. In addition, the non-crosslinked polymer powder here means
This shows a polymer powder in which at least the surface layer is composed of a non-crosslinked polymer. In addition, as the polymer powder, a polymer powder having a so-called core / shell structure composed of a core phase and a shell phase having different chemical compositions, structures, molecular weights, and the like of the polymers forming them is used. Can be. In this case, the core phase may be a non-crosslinked polymer or a crosslinked polymer, but the shell phase is preferably a noncrosslinked polymer.

The content of the acrylic polymer (B) is not particularly limited, but is preferably in the range of 0.1 to 30% by mass in the total amount of the acrylic BMC in the present invention. When the content is 0.1% by weight or more, a high thickening effect tends to be obtained, and when the content is 30% by weight or less, kneadability when producing an acrylic BMC tends to be good. It is in. The lower limit of the content is more preferably 1% by mass or more, and particularly preferably 3% by mass or more. About an upper limit, 25 mass% or less is more preferable, and its 20 mass% or less is especially preferable.

The weight average molecular weight of the acrylic polymer (B) is not particularly limited, but the larger the weight average molecular weight, the higher the thickening effect and the better the hot water resistance of the molded article. It is preferable that it is above.
Also, the upper limit of the weight average molecular weight is not particularly limited,
From the viewpoint of kneadability of the acrylic BMC, it is preferably 5,000,000 or less. The lower limit of the weight average molecular weight is more preferably 300,000 or more, and particularly preferably 500,000 or more. The upper limit is more preferably 4.5 million or less,
Particularly preferred is 4,000,000 or less. Here, the weight average molecular weight is a value in terms of polystyrene by the GPC method, and is measured under the following conditions according to the range of the weight average molecular weight.

When the weight average molecular weight is 100,000 or less; Apparatus: High speed GPC apparatus HLC-812 manufactured by Tosoh Corporation
0 column: TSKgelG2000HX, manufactured by Tosoh Corporation
L and TSKgelG4000HXL are connected in series. Oven temperature: 40 ° C. Eluent: tetrahydrofuran Sample concentration: 0.4% by mass Flow rate: 1 ml / min Injection volume: 0.1 ml Detector: RI (differential refractometer)

When the weight average molecular weight is more than 100,000 and less than 1,000,000; Apparatus: Tosoh Corporation, high speed GPC apparatus HLC-802
0 column: 3 pieces of TSKgelGMHXL manufactured by Tosoh Corporation
Oven temperature: 38 ° C Eluent: tetrahydrofuran Sample concentration: 0.4% by mass Flow rate: 1 ml / min Injection volume: 0.1 ml Detector: RI (differential refractometer)

When the weight average molecular weight is 1,000,000 or more; Apparatus: High-speed GPC apparatus HLC-802 manufactured by Tosoh Corporation
0 column: Tosoh Corporation, TSKgel, GMHHR-
H (30) connected in series Oven temperature: 40 ° C. Eluent: tetrahydrofuran Sample concentration: 0.4% by mass Flow rate: 1 ml / min Injection volume: 0.1 ml Detector: RI (differential refractometer)

Since the weight average molecular weight of a polystyrene standard polymer is only up to 20,000,000, when measuring a weight average molecular weight of 1,000,000 or more, a polystyrene calibration curve is determined by using a polystyrene calibration curve having a weight average molecular weight of 5 billion. Extrapolated to the point and converted. Further, as the acrylic polymer (B), two or more acrylic polymers different in at least one of the composition, molecular weight and particle size may be used in combination.

The method for producing the acrylic polymer (B) is not particularly limited, and it can be produced by a known polymerization method such as bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, and dispersion polymerization.

The inorganic filler (C) used in the present invention comprises:
It is a component that gives a marble-like deep texture and heat resistance to a molded product obtained by molding an acrylic BMC. The content of the inorganic filler (C) is not particularly limited, but is preferably in the range of 5 to 95% by mass based on the total amount of the acrylic BMC. This is because when the content of the component (C) is 5% by mass or more, the obtained molded article tends to have good texture and heat resistance,
Also, the shrinkage rate during curing tends to be low. On the other hand, when the content is 95% by mass or less, acrylic BMC
Tends to have good fluidity during molding. About the lower limit of this content, 20 mass% or more is more preferable,
Particularly preferred is 30% by mass or more. Moreover, about an upper limit, 80 mass% or less is preferable and 70 mass% or less is especially preferable.

The inorganic filler (C) is not particularly restricted but includes, for example, aluminum hydroxide, silica, fused silica, calcium carbonate, barium sulfate, titanium oxide, calcium phosphate, talc, mica, clay, glass powder and the like. No. Further, these inorganic fillers may be subjected to a surface treatment such as a silane treatment. These may be appropriately selected and used as needed, and two or more of them may be used in combination. Among them, aluminum hydroxide, calcium carbonate, silica, fused silica, and glass powder are preferred from the viewpoint of the texture of the obtained molded article.

The acrylic BMC of the present invention comprises the above components (A) to (C) as basic constituent components. A granite-like artificial marble having a pattern can be obtained.

A curing agent can be added to the acrylic BMC of the present invention, if necessary. The content of the curing agent is not particularly limited, but is preferably in the range of 0.01 to 10% by mass in the total amount of the acrylic BMC in the present invention. When the content is 0.01% by mass or more, the curability of the acrylic BMC tends to be sufficient, and when the content is 10% by mass or less, the storage stability of the acrylic BMC tends to be good. . Regarding the lower limit of this content,
0.05 mass% or more is more preferable, and 0.1 mass% or more is particularly preferable. The upper limit is more preferably 5% by mass or less, and particularly preferably 2% by mass or less.

The curing agent may be mixed after mixing the above-mentioned constituents into a rice cake-like material, or may be simultaneously mixed with the constituents. The kind of the curing agent is not particularly limited, and bis (4-t-butylcyclohexyl) peroxydicarbonate (Kakuyaku Akzo Co., Ltd.)
Trade name “Parcadox 16”, 10-hour half-life temperature = 44 ° C.), t-hexylperoxypivalate (trade name “Perhexyl PV”, manufactured by NOF Corporation, 10-hour half-life temperature = 53 ° C.) ), 3,5,5-trimethylhexanoyl peroxide (trade name “Perloyl 355”, manufactured by NOF Corporation, 10 hour half-life temperature = 59)
° C), lauroyl peroxide (manufactured by NOF Corporation,
Product name “PARLOIL L”, 10 hour half-life temperature = 62
° C), t-hexylperoxy-2-ethylhexanoate (trade name “Perhexyl O”, manufactured by NOF Corporation, 10-hour half-life temperature = 70 ° C), t-butylperoxy-2-ethylhexano Eat (manufactured by NOF Corporation,
Product name “Perbutyl O”, 10 hour half-life temperature = 72
℃), benzoyl peroxide (Kazaku Akzo Co., Ltd.)
Product name “Kadox B-CH50”, 10 hour half-life temperature = 72 ° C.), di-t-butylperoxy-2-methylcyclohexane (manufactured by NOF Corporation, product name “Perhexa MC”, 10 hours) (Half-life temperature = 83 ° C.), 1,1
-Bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane (trade name "PerhexaTMH", manufactured by NOF Corporation, 10 hour half-life temperature = 87 ° C),
1,1-bis (t-hexylperoxy) cyclohexane (trade name “Perhexa HC”, manufactured by NOF Corporation)
0 hour half-life temperature = 87 ° C.), 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane (trade name “Perhexa 3M”, manufactured by NOF CORPORATION), 1
0 hour half-life temperature = 90 ° C.), 1,1-bis (t-butylperoxy) cyclohexane (trade name “Perhexa C”, manufactured by NOF Corporation, 10-hour half-life temperature = 91)
C), 1,1-bis (t-butylperoxy) cyclododecane (trade name "Perhexa C", manufactured by NOF Corporation)
D ", 10-hour half-life temperature = 95 ° C.), t-hexylperoxyisopropyl carbonate (10-hour half-life temperature = 95 ° C.), t-amylperoxy-3,5,5-
Trimethylhexanoate (manufactured by Kayaku Akzo Co., Ltd., trade name “Kayaester AN”, 10-hour half-life temperature = 95)
C), 1,6-bis (t-butylperoxycarbonyloxy) hexane (trade name "Kayaren 6-70", manufactured by Kayaku Akzo Co., Ltd., 10-hour half-life temperature = 97C), t
-Butyl peroxy laurate (trade name "Perbutyl L", manufactured by NOF Corporation, 10-hour half-life temperature = 98
° C), t-butyl peroxyisopropyl carbonate (trade name “Perbutyl I”, manufactured by NOF Corporation, 10-hour half-life temperature = 99 ° C), t-butyl peroxy-2-
Ethylhexyl carbonate (manufactured by NOF CORPORATION, trade name “Perbutyl E”, 10-hour half-life temperature = 99 ° C.),
t-hexyl peroxybenzoate (Nippon Oil & Fats Co., Ltd.)
Product name “Perhexyl Z”, 10 hour half-life temperature =
99 ° C.), t-butylperoxy-3,5,5-trimethylhexanoate (trade name “Trigonox 42”, manufactured by Kayaku Akzo Co., Ltd., 10-hour half-life temperature = 100)
° C), t-amyl peroxybenzoate (manufactured by Kayaku Akzo Co., Ltd., trade name "KD-1", 10-hour half-life temperature =
100 ° C.), 2,2-bis (t-butylperoxy) butane (trade name “Perhexa 22”, manufactured by NOF Corporation),
10-hour half-life temperature = 103 ° C.), t-butyl peroxybenzoate (trade name “Perbutyl Z”, manufactured by NOF Corporation, 10-hour half-life temperature = 104 ° C.), n-butyl-4,4-bis (T-butylperoxy) valerate (trade name “Perhexa V”, manufactured by NOF Corporation, 10 hour half-life temperature = 105 ° C.), dicumyl peroxide (manufactured by NOF Corporation, trade name “Parkmill D”) 10-hour half-life temperature = 116 ° C.), 1,3-bis (t-butylperoxyisopropyl) benzoate (manufactured by Kayaku Akzo Co., Ltd., trade name “Parcadox 14”, 10-hour half-life temperature = 121) 2,2′-azobis-2,4-dimethylvaleronitrile (trade name “ADVN” manufactured by Otsuka Chemical Co., Ltd., 10-hour half-life temperature =).
52 ° C.), 1,1′-azobis (1-acetoxy-1-
Phenylethane) (Ottaka Chemical Co., Ltd., trade name "OTA
ZO-15 ", 10 hour half-life temperature = 61 ° C), 2,
2'-azobisisobutyronitrile (Otsuka Chemical Co., Ltd.)
Product name “AIBN”, 10 hour half-life temperature = 65
C), 2,2'-azobis-2-methylbutyronitrile (trade name "AMBN", manufactured by Otsuka Chemical Co., Ltd., 10-hour half-life temperature = 67C), dimethyl-2,2'-isobutyrate (Otsuka Chemical name “MAIB”, 10-hour half-life temperature = 67 ° C.), 1,1′-azobis-1-cyclohexanecarbonitrile (Otsuka Chemical Co., Ltd., product name “ACHN”, 10 A curing agent such as an azo compound such as (half-life temperature = 87 ° C.) can be used.

These curing agents can be appropriately selected and used in accordance with the molding temperature at the time of molding the acrylic BMC. However, from the viewpoint of the storage stability of the acrylic BMC, a 10-hour half-life temperature However, it is preferable to use a curing agent of 55 ° C. or higher. The 10-hour half-life temperature of the curing agent is more preferably at least 65 ° C, particularly preferably at least 75 ° C, most preferably at least 80 ° C.

The curing agents may be used alone or in combination of two or more having different half-life temperatures of 10 hours.

The acrylic BMC of the present invention may further include, if necessary, glass fibers,
Reinforcing materials such as carbon fiber, polymerization inhibitors, coloring agents, low shrinkage agents,
Various additives such as an internal mold release agent can be added.

In the present invention, the powder component of the acrylic monomer (A), acrylic polymer (B), and inorganic filler (C), which are the constituent components of the acrylic BMC, is used for 5 seconds. It is necessary to supply to the continuous twin-screw kneader within a range of ± 7% by mass with respect to a predetermined supply amount.

This is because, among the constituent components of the acrylic BMC, particularly, the component mass ratio of the powder component is different from that of the acrylic BMC.
This is because the appearance of the acrylic artificial marble obtained by molding is influenced. When the amount of the powder component exceeds ± 7% by mass with respect to the predetermined supply amount for 5 seconds, acrylic B
When continuous production of MC is continued for a long time, a portion where the mass ratio of the constituent components in the obtained acrylic BMC is not constant is locally generated, and the appearance and design of the obtained acrylic artificial marble tend to be impaired. The supply accuracy of this powder component is particularly high when obtaining dark acrylic artificial marble.
It is preferable that the amount be within a range of ± 2% by mass with respect to the predetermined supply for 5 seconds.

The supply method of the powder component in the present invention includes:
There is no particular limitation, and an intermittent feeder or a continuous feeder may be used, but in order to obtain the above-described powder component supply accuracy, the powder component is supplied to a continuous twin-screw kneader by a continuous feeder. Is preferred. When a continuous feeder is used, the component mass ratio of the obtained acrylic BMC tends to be more uniform than when an intermittent feed method such as a bucket feeder is used.

The continuous feeder used in the present invention is preferably at least one of a screw feeder, a vibratory feeder, a belt feeder, and a circle feeder.
These continuous feeders tend to allow the powder component to be supplied in a predetermined supply amount and in the aforementioned preferable supply mass range for the supply amount. These continuous feeders are
They may be used alone or in combination of two or more.

In the screw-type feeder, particularly when the supply amount of the powder component is large, the supply amount fluctuation in the same cycle as the screw rotation tends to occur because the diameter of the screw to be used becomes large. In order to stably secure the above-mentioned supply mass range, it is preferable to install a mesh at the tip of the supply pipe attached to the screw-type supply machine, and it is possible to minimize this periodic supply fluctuation. There is a tendency. It is also very preferable to use a method in which the powder component supplied from the screw-type supply device is supplied to the continuous twin-screw kneader after obtaining the supply step by the vibration-type supply device.

When a belt-type feeder is used, a doctor blade for maintaining a predetermined distance from the belt for enabling a constant supply of the powder component, and a doctor blade for maintaining a constant supply width of the powder component. It is preferable to use a pair of weir plates. The powder component tends to be constantly supplied in an area equivalent amount defined by them. When using a set of these belt-type feeders, the material and structure of the belt and the doctor blade are preferably determined under conditions that minimize the frictional force and snagging on the powder component, while the powder component is In particular, it is preferable to use a material that does not easily cause blocking at the doctor blade.

Further, the method of supplying the powder component supplied from the belt-type supply device to the continuous twin-screw kneader after passing through the supply step by the vibratory supply device is used. It is preferable because the supply fluctuation due to minute blocking generated in the blade tends to be minimized.

When a vibrating feeder is used, a doctor blade holding a predetermined distance from a vibrating plate and a powder for enabling a constant supply of powder components are used, as in the case of a belt-type feeder. It is preferable to use a pair of dams for keeping the body component supply width constant. The powder component tends to be constantly supplied in an area equivalent amount defined by them. When using a set of these vibratory feeders, the material and structure of the diaphragm, the doctor blade, and the weir are preferably determined under conditions that minimize frictional force and snagging on the powder components, As for the powder component, it is preferable to use a powder component which hardly causes blocking particularly at the doctor blade portion.

When a circle-type feeder is used, a fixed amount of powder components tends to be supplied similarly to the case of a belt-type feeder, and a doctor blade which holds a predetermined distance from a rotating plate must be used. Is preferred. The powder component is
The area equivalents defined by these tend to be constantly supplied constantly. When using a set of these circle-type feeders, the material and structure of the rotating plate and the doctor blade are preferably determined under conditions that minimize frictional force and snagging on the powder component, while the powder component Regarding the above, it is particularly preferable to use a material that does not easily cause blocking at the doctor blade portion. In the case of a circle type feeder, it is possible to use a known technique in which the powder on the lowermost rotary plate has a stable property by providing a plurality of rotary plates.

The specific example of the continuous feeder has been described above.
These may be appropriately selected and used according to the properties of the powder used and the powder supply speed.

In the present invention, the components (A) to (C) and, if desired, a curing agent and resin particles containing an inorganic filler are charged into a continuous twin-screw kneader by simultaneously charging each component. Alternatively, after pre-mixing each component in advance,
May be thrown. Specifically, for example, after dissolving a part of the component (B) in the component (A) in advance and increasing the viscosity to some extent to obtain an acrylic syrup having good handleability, the acrylic syrup and the component The remainder of component (B) and component (C) may be charged into a continuous twin-screw kneader. Also,
In this case, instead of dissolving a part of the component (B) in the component (A), the component (A) is partially polymerized in advance to form the polymer (B) as the polymer in the component (A). Acrylic syrup may be used. Further, for example, the components (B) and (C), which are powdery components, may be preliminarily mixed, and this mixture may be charged into a continuous twin-screw kneader.

In this way, the components including the components (A) to (C) are quantitatively supplied to the continuous twin-screw kneader,
After a predetermined kneading time, an acrylic BMC is obtained. In the present invention, the kneading time (acrylic BM
Time during which the component C stays in the continuous twin-screw kneader)
Is not particularly limited, but is preferably within 3 minutes. When the kneading time is within 3 minutes, the heat history of the acrylic BMC during kneading is reduced, and the storage stability of the obtained acrylic BMC tends to be good. The upper limit of the kneading time is preferably within 2 minutes, particularly preferably within 1 minute. The lower limit is not particularly limited, but is preferably 10 seconds or more, and more preferably 20 seconds or more.

The acrylic BMC obtained in the present invention thickens to such a level that there is no stickiness even in such a short time, so that the handleability is good even immediately after discharging from a continuous twin-screw kneader. Acrylic BM obtained by the present invention
C is discharged from a continuous twin-screw kneader, and may be molded by heating and pressurizing without aging as it is, or, if necessary, discharged from a continuous twin-screw kneader and aged. After that, it may be molded by heating and pressurizing.

Here, the continuous twin-screw kneader referred to in the present invention is a twin-screw kneader having a kneading function and an extruding function inside, and continuously feeds raw materials to the inside of the apparatus. This is a device that performs kneading and continuously extrudes the kneaded material. For example, a device that carries a screw inside the device may be mentioned, but the device is not limited to this. The screw preferably has a structure through which a heat medium for temperature control can pass, and a structure in which the barrel can also control the temperature. The heat medium for temperature control (heating or cooling) used for kneading is not particularly limited, and examples thereof include water, ethylene glycol, and silicone oil. The temperature of the acrylic BMC discharged from the continuous twin-screw kneader varies depending on conditions such as the composition, the raw material temperature, the kneading time, the viscosity of the BMC, and the shear heat generation. In some cases. The screw diameter, length, groove depth, and number of rotations may be appropriately selected according to the required throughput and viscosity of the mixture. As the continuous twin-screw kneader, a known device can be used, and for example, a KRC kneader manufactured by Kurimoto Iron Works, Ltd. can be used.

In the present invention, the acrylic BMC obtained by kneading and thickening each of the above-mentioned components may be extruded as it is from the tip of the continuous twin-screw kneader into a columnar shape.
A die is attached to the tip of a continuous twin-screw kneader, and the die is continuously shaped into a predetermined shape.
It can also be performed in a process.

Next, the acrylic artificial marble of the present invention will be described. The acrylic artificial marble of the present invention has colorimetric values (L ^* ,
a ^* , b ^* ), the color difference between each colorimetric point (△
This is an acrylic molded product having a maximum value of E ^* ) (ΔE ^* MAX) of 3.0 or less, and has excellent appearance without color spots. Usually, when the color difference exceeds 1.0, there is a tendency that color spots can be visually judged. The color difference (△ E ^* ) here is
Color difference meter (HANDY made by NIPPON DENSHOKU)
CORROMETER NR-3000), colorimetric values (L ^* ,
a ^* , b ^* ), the color difference between each colorimetric point (ΔE
^* ) Means the maximum value (ΔE ^* MAX).
The color spot tends to be more likely to appear as the molded product is darker, that is, as the L ^* is smaller. Usually, when the color difference (ΔE ^* ) is large, the color spot tends to be visually determined. The acrylic artificial marble of the present invention has a maximum color difference (ΔE ^* ) (ΔE ^* MAX) of 3.0 particularly when the colorimetric value is L ^* ≦ 70.
It has the following excellent appearance, and is preferably 1.0 or less, more preferably 0.7 or less, and particularly preferably 0.5 or less. Specific examples of the heating and pressurizing curing include a press molding method, an injection molding method, and an extrusion molding method, but are not particularly limited. In this case, the heating temperature is not particularly limited, but may be 80 to 15
It is preferably in the range of 0 ° C. When the heating temperature is 80 ° C. or higher, the curing time can be shortened, and the productivity tends to increase. When the heating temperature is 150 ° C. or lower, the appearance of the obtained molded article tends to be good. The lower limit of the heating temperature is more preferably 85 ° C or higher, and the upper limit is more preferably 140 ° C or lower. Further, the upper mold and the lower mold may be heated with a temperature difference within this temperature range. The pressurizing pressure is not particularly limited, but is 1 to 20
It is preferably within the range of MPa. When the pressure is 1 MPa or more, the filling property of the acrylic BMC into the mold tends to be good, and when the pressure is 20 MPa or less, a good molded appearance tends to be obtained. The lower limit of the applied pressure is more preferably 2 MPa or more, and the upper limit is more preferably 15 MPa or less. The molding time may be appropriately selected depending on the thickness of the molded product.

[0050]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples. All parts and percentages in the examples are based on mass. In the examples, the color measurement of the acrylic artificial marble is based on JIS.
L ^* , a ^* , b ^* based on Z 8720-1980
Was measured, and a color difference (ΔE ^* ) was determined from these values.

(1) Production Example of Polymer Powder (P) In a reaction vessel equipped with a cooling pipe, a thermometer, a stirrer, a dropping device, and a nitrogen introduction pipe, 750 parts of pure water and sodium alkyldiphenyl ether sulfonate as a surfactant were added. (Kao Corporation, trade name “Perex SS-H”) (4 parts) and potassium persulfate (1 part) as a polymerization initiator were charged and heated to 70 ° C. while stirring under a nitrogen atmosphere. to this,
A mixture consisting of 500 parts of methyl methacrylate and 5 parts of a surfactant sodium dialkyl sulfosuccinate (trade name “Perex OT-P” manufactured by Kao Corporation) was added dropwise over 3 hours, and then kept for 1 hour, and further kept at 80 ° C. After maintaining the temperature for 1 hour and cooling to room temperature, the emulsion polymerization was terminated to obtain an emulsion. The average particle size of the primary particles of the polymer of the obtained emulsion was 0.10 μm. Next, this emulsion was spray-dried using a spray-drying apparatus (L-8 type manufactured by Okawara Kakoki Co., Ltd.) at an inlet temperature / outlet temperature = 150 ° C./90° C. to obtain a polymer powder (P). Was. The average particle size of the obtained polymer powder (P) was 30 μm.

Example 1 6.5 parts of methyl methacrylate (trade name "Acryester M" manufactured by Mitsubishi Rayon Co., Ltd.) and isobornyl methacrylate (Mitsubishi Rayon Co., Ltd.) were used as the acrylic monomer (A). 6.5 parts, Neopentyl glycol dimethacrylate (manufactured by Shin-Nakamura Kagaku Co., Ltd., trade name "NK")
10.4 parts of ester NPG), 0.01 part of 2,6-di-t-butyl-4-methylphenol (manufactured by Sumitomo Chemical Co., Ltd., trade name "Sumilyzer BHT"), and pigment (COLORTEX manufactured by Sanyo Pigment Co., Ltd.) GREEN # 402) 5.
Charge the mixture consisting of 5 parts into a tank and add it to the soldier equipment.
With a snake pump, continuous twin-screw kneader S-2 KRC kneader manufactured by Kurimoto Iron Works, screw diameter = 50m
m, L / D = 13.7). The charging speed was accurate to within (42.2 ± 0.80) g / 5 seconds. As the acrylic polymer (B), the polymer powder (P-1) was charged into a SUS container attached to a screw feeder made by Kuma Engineering, and was continuously charged into a hopper attached to a continuous twin-screw kneader. The charging rate was accurate to within (22.8 ± 1.5) g / 5 seconds. Aluminum hydroxide (manufactured by Sumitomo Chemical Co., Ltd., trade name “CWL-325J”) as an inorganic filler (C) is attached to a screw feeder manufactured by Kuma Engineering.
The mixture was charged in a container and continuously charged into a hopper attached to a continuous twin-screw kneader. The injection speed was accurate to within (89 ± 6) g / 5 seconds. As a curing agent, 1,1-bis (t
-Butylperoxy) 3,3,5-trimethylcyclohexane (trade name "Perhexa 3" manufactured by NOF Corporation)
M, 10-hour half-life temperature = 90 ° C.) was charged into a tank, and was continuously charged into a hopper attached to a continuous twin-screw kneader by a snake pump manufactured by Hyojin Equipment Co., Ltd. The charging speed was accurate to within (0.88 ± 0.06) g / 5 seconds. In addition, a heating medium whose temperature was controlled at 45 ° C. was passed through the barrel jacket of the continuous twin-screw kneader.

According to the above method, the components (A) to (C) and the curing agent are simultaneously charged into a continuous twin-screw kneader, and kneading and thickening are performed in a continuous twin-screw kneader in one step. Acrylic BMC was continuously produced from a continuous twin-screw kneader at a rate of 112 kg / h for about 4 hours. The time the material stayed in the continuous twin-screw kneader was about 2 minutes. The obtained sheet-shaped acrylic BMC was a BMC having good tackiness without stickiness even immediately after being discharged from the tip of the continuous twin-screw kneader.

Next, from the sheet-like acrylic BMC, 700 g each was randomly sampled at five points. The sampled acrylic BMC (700 g) was filled into a 200 mm square flat plate forming die, and the upper die temperature was set to 1.
Heat-press curing for 10 minutes at 30 ° C., lower mold temperature 115 ° C., pressure 10 MPa, press-mold, thickness 10m
Thus, five acrylic artificial marble flat plates of m were obtained.

For each of the obtained flat plates (five sheets), five points (nearly four corners and the center) were measured with a colorimeter (NI).
HANDY COLOR made by PPON DENSHOKU
(IMETER NR-3000), and the color difference (ΔE ^* ) was determined from these values. Here, L ^{* of} each plate
Was 32. Table 1 shows the maximum value (hereinafter referred to as ΔE ^* MAX) of the color difference (ΔE ^* ) for each flat plate calculated based on this. As a result, ΔE of five obtained flat plates was obtained.
^* The maximum value of MAX was 0.46. Further, no color difference between these plates could be confirmed visually.

[0056]

[Table 1]

[Example 2] The acrylic monomer (A) used in Example 1 was produced by a continuous twin-screw kneader (Kurimoto Iron Works) using a snake pump (Hyojin Equipment Co., Ltd.). S-2 type KR
C kneader, screw diameter = 50 mm, L / D = 13.
It was continuously charged into the hopper attached to 7). The charging speed was accurate to within (42.2 ± 0.79) g / 5 seconds.
The acrylic polymer (B) used in Example 1 was continuously charged into a hopper attached to a continuous twin-screw kneader using a screw feeder manufactured by Kuma Engineering. The tip of the supply pipe attached to the screw feeder has a wire diameter of 0.8 mm.
Stainless steel 4-mesh wire mesh was installed. At this time, the charging speed was accurate within (22.8 ± 1.1) g / 5 seconds. The inorganic filler (C) used in Example 1 was continuously charged into a hopper attached to a continuous twin-screw kneader using a screw feeder manufactured by Kuma Engineering. In addition, a stainless steel 4-mesh wire net having a wire diameter of 0.8 mm was installed at the tip of the supply pipe attached to the screw feeder. At this time, the charging speed is (89 ± 5.
1) The accuracy was within g / 5 seconds. The curing agent used in Example 1 was continuously charged into a hopper attached to a continuous twin-screw kneader by a snake pump manufactured by Hyojin Equipment Co., Ltd. The charging speed was accurate to within (0.88 ± 0.05) g / 5 seconds. In addition, a heating medium whose temperature was controlled at 45 ° C. was passed through the barrel jacket of the continuous twin-screw kneader.

According to the above method, the components (A) to (C) and the curing agent are simultaneously charged into a continuous twin-screw kneader, and kneading and thickening are performed in a continuous twin-screw kneader in one step. Acrylic BMC was continuously produced from a continuous twin-screw kneader at a rate of 112 kg / h for about 4 hours. The time the material stayed in the continuous twin-screw kneader was about 2 minutes. The obtained sheet-shaped acrylic BMC was a BMC having good tackiness without stickiness even immediately after being discharged from the tip of the continuous twin-screw kneader.

Next, five acrylic artificial marble flat plates were obtained from the sheet-like acrylic BMC in the same manner as in Example 1. Table 2 shows ΔE ^* MAX of each of the obtained flat plates (5 sheets) calculated in the same manner as in Example 1.
Shown in Here, the average value of L ^* of each plate was 32. As a result, the maximum value of ΔE ^* MAX of the five obtained flat plates was 0.38. Further, no color difference between these plates could be confirmed visually.

[0060]

[Table 2]

Example 3 The acrylic monomer (A) used in Example 1 was manufactured by a continuous twin-screw kneader (manufactured by Kurimoto Ironworks Co., Ltd.) using a snake pump manufactured by Hyojin Equipment Co., Ltd. S-2 type KR
C kneader, screw diameter = 50 mm, L / D = 13.
It was continuously charged into the hopper attached to 7). The charging speed was accurate to within (42.2 ± 0.80) g / 5 seconds.
The acrylic polymer (B) used in Example 1 was converted to a Shinko Electric Co., Ltd. using a screw feeder manufactured by Kuma Engineering.
It was supplied onto a diaphragm of a vibratory feeder (model: DRVF-300-1.5), and then continuously fed from the diaphragm into a hopper attached to a continuous twin-screw kneader. The tip of the supply pipe attached to the screw feeder has a wire diameter of 0.8 mm.
Stainless steel 4-mesh wire mesh was installed. At this time, the charging speed was accurate within (22.8 ± 0.6) g / 5 seconds. The inorganic filler (C) used in Example 1 was supplied to a vibration feeder manufactured by Shinko Electric Co., Ltd. (model: DRVF-) using a screw feeder manufactured by Kuma Engineering.
300-1.5), and then continuously fed from the diaphragm to a hopper attached to a continuous twin-screw kneader. In addition, a stainless steel 4-mesh wire net having a wire diameter of 0.8 mm was installed at the tip of the supply pipe attached to the screw feeder. At this time, the charging speed is (89 ± 2.
5) The accuracy was within g / 5 seconds. The curing agent used in Example 1 was continuously charged into a hopper attached to a continuous twin-screw kneader by a snake pump manufactured by Hyojin Equipment Co., Ltd. The charging speed was accurate to within (0.88 ± 0.06) g / 5 seconds. In addition, a heating medium whose temperature was controlled at 45 ° C. was passed through the barrel jacket of the continuous twin-screw kneader.

According to the above method, the components (A) to (C) and the curing agent are simultaneously charged into a continuous twin-screw kneader, and kneading and thickening are performed in a continuous twin-screw kneader in one step. Acrylic BMC was continuously produced from a continuous twin-screw kneader at a rate of 112 kg / h for about 4 hours. The time the material stayed in the continuous twin-screw kneader was about 2 minutes. The obtained sheet-shaped acrylic BMC was a BMC having good tackiness without stickiness even immediately after being discharged from the tip of the continuous twin-screw kneader. Next, five acrylic artificial marble plates were obtained from the sheet-like acrylic BMC in the same manner as in Example 1. About this obtained flat plate (5 sheets), ΔE ^{* for} each flat plate calculated in the same manner as in Example 1 ^.
MAX is shown in Table 3. Here, the average value of L ^* of each plate was 32. As a result, ΔE of five obtained flat plates was obtained.
^* The maximum value of MAX was 0.22. Further, no color difference between these plates could be confirmed visually.

[0063]

[Table 3]

Example 4 The acrylic monomer (A) used in Example 1 was continuously twin-screw kneader (manufactured by Kurimoto Ironworks Co., Ltd.) with a snake pump manufactured by Hyojin Equipment Co., Ltd. S-2 type KR
C kneader, screw diameter = 50 mm, L / D = 13.
It was continuously charged into the hopper attached to 7). The charging speed was accurate to within (42.2 ± 0.77) g / 5 seconds.
The acrylic polymer (B) used in Example 1 was used as a vibration feeder (model: DRVF-300-1. Manufactured by Shinko Electric Co., Ltd.).
In 5), the mixture was continuously charged into a hopper attached to a continuous twin-screw kneader. At this time, the charging speed is (22.8 ± 1.3)
The accuracy was within g / 5 seconds. The inorganic filler (C) used in Example 1 was replaced with a vibration feeder (model: Shinko Electric Co., Ltd.).
DRVF-300-1.5), and continuously charged into a hopper attached to a continuous twin-screw kneader. At this time, the charging speed was accurate within (89 ± 5.8) g / 5 seconds. The curing agent used in Example 1 was continuously charged into a hopper attached to a continuous twin-screw kneader by a snake pump manufactured by Hyojin Equipment Co., Ltd. The charging speed was accurate to within (0.88 ± 0.05) g / 5 seconds. In addition, a heating medium whose temperature was controlled at 45 ° C. was passed through the barrel jacket of the continuous twin-screw kneader.

According to the above method, the components (A) to (C) and the curing agent are simultaneously charged into a continuous twin-screw kneader, and kneading and thickening are performed in a continuous twin-screw kneader in one step. Acrylic BMC was continuously produced from a continuous twin-screw kneader at a rate of 112 kg / h for about 4 hours. The time the material stayed in the continuous twin-screw kneader was about 2 minutes. The obtained sheet-shaped acrylic BMC was a BMC having good tackiness without stickiness even immediately after being discharged from the tip of the continuous twin-screw kneader. Next, five acrylic artificial marble plates were obtained from the sheet-like acrylic BMC in the same manner as in Example 1. For the obtained flat plates (5), ΔE ^* M for each flat plate calculated in the same manner as in Example 1.
AX is shown in Table 4. Here, the average value of L ^* of each plate was 32. As a result, ΔE ^*
The maximum value of MAX was 0.44. Further, no color difference between these plates could be confirmed visually.

[0066]

[Table 4]

[Example 5] The acrylic monomer (A) used in Example 1 was mixed with a continuous twin-screw kneader (manufactured by Kurimoto Tekkosho Co., Ltd.) using a snake pump manufactured by Hyojin Equipment Co., Ltd. S-2 type KR
C kneader, screw diameter = 50 mm, L / D = 13.
It was continuously charged into the hopper attached to 7). The charging speed was accurate to within (42.2 ± 0.79) g / 5 seconds.
The acrylic polymer (B) used in Example 1 was continuously charged into a hopper attached to a continuous twin-screw kneader using a belt feeder manufactured by Kuma Engineering. At this time, the charging speed was accurate within (22.8 ± 1.4) g / 5 seconds. The inorganic filler (C) used in Example 1 was continuously charged into a hopper attached to a continuous twin-screw kneader using a belt feeder manufactured by Kuma Engineering. At this time, the charging speed was accurate within (89 ± 5.7) g / 5 seconds. The curing agent used in Example 1 was continuously charged into a hopper attached to a continuous twin-screw kneader by a snake pump manufactured by Hyojin Equipment Co., Ltd. The charging speed was accurate to within (0.88 ± 0.06) g / 5 seconds. In addition, a heating medium whose temperature was controlled at 45 ° C. was passed through the barrel jacket of the continuous twin-screw kneader.

According to the above method, the components (A) to (C) and the curing agent are simultaneously charged into a continuous twin-screw kneader, and kneading and thickening are performed in a continuous twin-screw kneader in one step. Acrylic BMC was continuously produced from a continuous twin-screw kneader at a rate of 112 kg / h for about 4 hours. The time the material stayed in the continuous twin-screw kneader was about 2 minutes. The obtained sheet-shaped acrylic BMC was a BMC having good tackiness without stickiness even immediately after being discharged from the tip of the continuous twin-screw kneader.

Next, five acrylic artificial marble plates were obtained from the sheet-like acrylic BMC in the same manner as in Example 1. Table 5 shows ΔE ^* MAX of each of the obtained flat plates (5 sheets) calculated in the same manner as in Example 1.
Shown in Here, the average value of L ^* of each plate was 32. As a result, the maximum value of ΔE ^* MAX of the five obtained flat plates was 0.43. Further, no color difference between these plates could be confirmed visually.

[0070]

[Table 5]

Example 6 The acrylic monomer (A) used in Example 1 was continuously twin-screw kneader (manufactured by Kurimoto Ironworks Co., Ltd.) using a snake pump manufactured by Hyojin Equipment Co., Ltd. S-2 type KR
C kneader, screw diameter = 50 mm, L / D = 13.
It was continuously charged into the hopper attached to 7). The charging speed was accurate to within (42.2 ± 0.81) g / 5 seconds.
The acrylic polymer (B) used in Example 1 was supplied onto a diaphragm of a vibration feeder (model: DRVF-300-1.5) manufactured by Shinko Electric Co., Ltd. using a belt feeder manufactured by Kuma Engineering, Thereafter, the mixture was continuously charged from a diaphragm into a hopper attached to a continuous twin-screw kneader. At this time, the charging speed was accurate within (22.8 ± 1.0) g / 5 seconds. The inorganic filler (C) used in Example 1 was supplied onto a diaphragm of a vibration feeder (model: DRVF-300-1.5) manufactured by Shinko Electric Co., Ltd. using a belt feeder manufactured by Kuma Engineering, and thereafter The mixture was continuously charged from a diaphragm into a hopper attached to a continuous twin-screw kneader. At this time, the charging speed was accurate within (89 ± 3.7) g / 5 seconds. The curing agent used in Example 1 was continuously charged into a hopper attached to a continuous twin-screw kneader by a snake pump manufactured by Hyojin Equipment Co., Ltd. The charging speed was accurate to within (0.88 ± 0.05) g / 5 seconds. In addition, a heating medium whose temperature was controlled at 45 ° C. was passed through the barrel jacket of the continuous twin-screw kneader.

According to the above method, the components (A) to (C) and the curing agent are simultaneously charged into a continuous twin-screw kneader, and kneading and thickening are performed in one step in the continuous twin-screw kneader. Acrylic BMC was continuously produced from a continuous twin-screw kneader at a rate of 112 kg / h for about 4 hours. The time the material stayed in the continuous twin-screw kneader was about 2 minutes. The obtained sheet-shaped acrylic BMC was a BMC having good tackiness without stickiness even immediately after being discharged from the tip of the continuous twin-screw kneader.

Next, five acrylic artificial marble plates were obtained from the sheet-like acrylic BMC in the same manner as in Example 1. Table 6 shows ΔE ^* MAX of each of the obtained flat plates (5 sheets) calculated in the same manner as in Example 1.
Shown in Here, the average value of L ^* of each plate was 32. As a result, the maximum value of ΔE ^* MAX of the five obtained flat plates was 0.31. Further, no color difference between these plates could be confirmed visually.

[0074]

[Table 6]

[Example 7] The acrylic monomer (A) used in Example 1 was manufactured by a continuous twin-screw kneader (manufactured by Kurimoto Iron Works, Ltd.) using a snake pump manufactured by Hyojin Equipment Co., Ltd. S-2 type KR
C kneader, screw diameter = 50 mm, L / D = 13.
It was continuously charged into the hopper attached to 7). The charging speed was accurate to within (42.2 ± 0.78) g / 5 seconds.
The acrylic polymer (B) used in Example 1 was converted to a circle feeder manufactured by Akatake Engineering (model: Hi-30).
At 0), the mixture was continuously charged into a hopper attached to a continuous twin-screw kneader. At this time, the charging speed is (22.8 ± 1.1)
The accuracy was within g / 5 seconds. The inorganic filler (C) used in Example 1 was continuously charged into a hopper attached to a continuous twin-screw kneader using a circle feeder (model: Hi-300) manufactured by Akatake Engineering. At this time, the charging speed was accurate within (89 ± 5.0) g / 5 seconds. The curing agent used in Example 1 was continuously charged into a hopper attached to a continuous twin-screw kneader by a snake pump manufactured by Hyojin Equipment Co., Ltd. The charging speed was accurate to within (0.88 ± 0.06) g / 5 seconds. In addition, a heating medium whose temperature was controlled at 45 ° C. was passed through the barrel jacket of the continuous twin-screw kneader.

According to the above method, the components (A) to (C) and the curing agent are simultaneously charged into a continuous twin-screw kneader, and kneading and thickening are performed in a continuous twin-screw kneader in one step. Acrylic BMC was continuously produced from a continuous twin-screw kneader at a rate of 112 kg / h for about 4 hours. The time the material stayed in the continuous twin-screw kneader was about 2 minutes. The obtained sheet-shaped acrylic BMC was a BMC having good tackiness without stickiness even immediately after being discharged from the tip of the continuous twin-screw kneader. Next, five acrylic artificial marble plates were obtained from the sheet-like acrylic BMC in the same manner as in Example 1. About this obtained flat plate (5 sheets), ΔE ^{* for} each flat plate calculated in the same manner as in Example 1 ^.
Table 7 shows MAX. Here, the average value of L ^* of each plate was 32. As a result, ΔE of five obtained flat plates was obtained.
^* The maximum value of MAX was 0.37. Further, no color difference between these plates could be confirmed visually.

[0077]

[Table 7]

Comparative Example 1 The acrylic monomer (A) used in Example 1 was continuously twin-screw kneader (manufactured by Kurimoto Ironworks Co., Ltd.) using a snake pump manufactured by Hyojin Equipment Co., Ltd. S-2 type KR
C kneader, screw diameter = 50 mm, L / D = 13.
It was continuously charged into the hopper attached to 7). The charging speed was accurate to within (8.35 ± 0.16) g / 5 seconds.
The acrylic polymer (B) used in Example 1 was charged into a SUS container attached to a screw feeder made by Kuma Engineering, and was continuously charged into a hopper attached to a continuous twin-screw kneader. At this time, the charging speed is (4.51 ± 0.
37) The accuracy was within g / 5 seconds. The inorganic filler (C) used in Example 1 was charged into a SUS container attached to a screw feeder made by Kuma Engineering, and was continuously charged into a hopper attached to a continuous twin-screw kneader. At this time, the charging speed was accurate within (17.6 ± 1.4) g / 5 seconds. The curing agent used in Example 1 was replaced with a soldier equipment, Inc.
With a snake pump made by the company, it was continuously charged into a hopper attached to a continuous twin-screw kneader. The charging speed is (0.17 ± 0.
003) Accuracy within g / 5 seconds. In addition, a heating medium whose temperature was controlled at 45 ° C. was passed through the barrel jacket of the continuous twin-screw kneader.

According to the above method, the components (A) to (C) and the curing agent are simultaneously charged into a continuous twin-screw kneader, and kneading and thickening are performed in a continuous twin-screw kneader in one step. Acrylic BMC was continuously produced from a continuous twin-screw kneader at a rate of 22 kg / h for about 4 hours. The time the material stayed in the continuous twin-screw kneader was about 2 minutes. The obtained sheet-shaped acrylic BMC was a BMC having good tackiness without stickiness even immediately after being discharged from the tip of the continuous twin-screw kneader.

Next, five acrylic artificial marble flat plates were obtained from the sheet-like acrylic BMC in the same manner as in Example 1. Table 8 shows ΔE ^* MAX of each of the obtained flat plates (5 sheets) calculated for each flat plate in the same manner as in Example 1.
Shown in Here, the average value of L ^* of each plate was 32. As a result, the maximum value of ΔE ^* MAX of the five obtained flat plates was 4.10. Further, the color difference could be confirmed by visual inspection of each of these plates.

[0081]

[Table 8]

[0082]

As described above, the acrylic BMC of the present invention
Makes it possible to obtain high quality acrylic BMC with very high production efficiency. Further, the acrylic artificial marble of the present invention has excellent appearance without color spots, and is industrially very useful.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08F 2/44 C08F 2/44 C 20/00 20/00 265/00 265/00 C08J 3/20 CEY C08J 3/20 CEYC C08K 3/00 C08K 3/00 5/09 5/09 5/10 5/10 // B29K 33:00 503: 04 C04B 111: 54 (72) Inventor Akimasa Yanase Sunadabashi, Higashi-ku, Nagoya City, Aichi Prefecture 4-60-1 Mitsubishi Rayon Co., Ltd. Product Development Laboratory (72) Inventor Yuji Kazahaya 4-1-1 Sunadabashi Higashi-ku Nagoya-shi, Aichi Japan Mitsubishi Rayon Co., Ltd. Product Development Laboratory

Claims (6)

[Claims] 1. A method for producing an acrylic BMC comprising an acrylic monomer (A), an acrylic polymer (B) and an inorganic filler (C) as constituents, wherein: A method for producing an acrylic BMC, wherein a powder component is supplied to a continuous twin-screw kneader within a range of ± 7% by mass with respect to a predetermined supply amount for 5 seconds. 2. The method for producing an acrylic BMC according to claim 1, wherein the powder component is supplied to a continuous twin-screw kneader by a continuous feeder. 3. The method for producing an acrylic BMC according to claim 2, wherein the continuous feeder is one of a screw feeder, a vibratory feeder and a belt feeder. 4. The method for producing an acrylic BMC according to claim 2, wherein a mesh is provided at a tip of a supply pipe attached to the continuous feeder. 5. The powder component supplied from a screw type feeder or a belt type feeder is supplied to a continuous twin-screw kneader after passing through a supply step by a vibratory feeder. 5. The method for producing an acrylic BMC according to 3 or 4. 6. A colorimetric value (L ^* , a ^* , b ^* ) measured at three or more arbitrary positions obtained by heating and pressurizing an acrylic BMC obtained by a continuous production method. The maximum value (ΔE ^* MA) of the color difference (ΔE ^* ) between
Acrylic artificial marble, wherein X) is 3.0 or less.