JPH09302100A - Crosslinked alkyl methacrylate polymer molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a methacrylate polymer molding which has excellent bendability, can be bent under heating without forming any internal strain at the bent, can give bent articles freed from cracks and breaks and having excellent impact resistance, is so excellent in mold release that it can be produced in good productivity, and has transparent appearance, clear hue and the appearance of a quality article. SOLUTION: This molding contains an inorganic filler and has an α-dispersion peak temperature of the loss elastic modulus (E") in dynamic viscoelastic properties of 100 deg.C or above, a peak value of the tan δ in dynamic viscoelastic properties of 0.8 or above, and the storage modulus at 160 deg.C on the plateau in a rubbery state of 30MPa or below.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a crosslinked methacrylic polymer molded article. More specifically, the present invention is excellent in mold releasability from a molding die, does not cause internal strain in a bent portion when bent under heating and has excellent impact resistance, and does not cause cracking or damage. Moreover, the present invention relates to a crosslinked alkylmethacrylate-based polymer molded product containing an inorganic filler, which is transparent and has a high-grade feeling excellent in color tone. Therefore, the molded product of the present invention is manufactured with good workability and high productivity. In addition, it can be easily processed into a product of the desired shape and structure at low cost by secondary processing under heating.By utilizing such characteristics, the top plate of the system kitchen, the door, It can be effectively used for a wide range of purposes, including interior materials and equipment for homes such as walls, vanity tops, unit bath waist walls, aprons, bay window counters, etc.

[0002]

BACKGROUND OF THE INVENTION Acrylic resins have been used in a wide range of fields as lighting covers, automobile parts, optical parts such as lenses and prisms, etc. due to their excellent weather resistance and outstanding transparency. Further, in recent years, with the expansion of the use of acrylic resin, application development has also been carried out as an interior member of a building material, and for example, acrylic artificial marble has been developed. Acrylic artificial marble is usually a cell cast method or continuous cast method in which a polymerizable highly viscous liquid whose main component is methyl methacrylate is mixed with an inorganic filler such as aluminum hydroxide, a decorating agent and a polymerization initiator. After being polymerized and solidified into a plate shape with, the product is cut into a desired size and is commercially available. Specific applications include the top panel of system kitchens, doors and walls, top panels of vanities, waist walls and aprons of unit baths, and bay window counters.

However, when the plate-like body made of an acrylic resin is used for the above-mentioned applications, it is necessary to perform processing such as cutting and cutting in accordance with the size of the place of use, especially when forming a curved surface. A complicated process such as shaving the end surface to a desired curvature R and further polishing is required, resulting in an increase in cost in terms of material and processing. In addition, the processing method is limited even for a material that can be heat-bended by a thin plate-shaped molded product of acrylic resin of 2 to 3 mm, and cooling distortion remains on the curved surface part formed by secondary processing, etc. There is a problem that cracks and breakages occur with a slight impact from. Furthermore, in the case of a conventional artificial marble-like molded product made of an alkyl methacrylate resin, the mold releasability from the mold is poor, and it is difficult to obtain a molded product with good workability and high productivity.

[0004]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is that it is excellent in bending workability and can easily and smoothly heat a molded product such as a plate-like body without cutting or polishing. An object of the present invention is to provide an alkylmethacrylate-based polymer molded article that can be bent downward, has no internal strain in a bent article, has excellent impact resistance, and does not cause cracking or damage. . And the object of the present invention is
It is an object of the present invention to provide a high-quality alkyl methacrylate polymer molded article having a transparent feeling, a clear color tone, and a high-grade feeling. Furthermore, an object of the present invention is to provide an alkylmethacrylate-based polymer having excellent mold releasability from a molding die and capable of obtaining a molded product having a target shape and size with high dimensional accuracy and good workability and productivity. Concerning united molded articles.

[0005]

[Means for Solving the Problem] The present inventors have made various studies in order to achieve the above object. As a result, each physical property value of the dynamic viscoelastic property, that is, the α dispersion peak temperature of loss elastic modulus (E ″) in the dynamic viscoelastic property, tan δ
The crosslinked alkylmethacrylate-based polymer molded product containing an inorganic filler, which has a specific value of the peak value of and a storage elastic modulus at 160 ° C. in a rubbery flat region, has good bending workability under heating and is bent after cooling. It does not cause internal strain in the processed part and has excellent impact resistance, no cracks or damage,
Moreover, it was found that such a molded article has excellent mold releasability from the molding die, which makes the workability and productivity at the time of molding extremely excellent, and has a transparent feeling, a clear color tone and a high-class feeling. As a result, the present invention has been completed.

That is, the present invention is a crosslinked alkylmethacrylate polymer molded product containing an inorganic filler, wherein (i) the loss dispersion modulus (E ″) in the dynamic viscoelastic property has an α dispersion peak temperature of 100. (Ii) the peak value of tan δ in the dynamic viscoelastic property is 0.8 or more; and (iii) the storage elastic modulus at the rubbery flat region of 160 ° C. is 30 MPa or less. i) to (iii)
And a crosslinked alkylmethacrylate polymer molded article.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. The crosslinked alkyl methacrylate polymer molded article of the present invention is an alkyl methacrylate homopolymer, or a large proportion of alkyl methacrylate units and a small proportion of other α,
A molded article made of a crosslinked alkylmethacrylate-based polymer in which an alkylmethacrylate copolymer having a copolymerized unit of β-ethylenically unsaturated monomer is crosslinked by a crosslinking agent, wherein the molded article is an inorganic filler. Contains.

Crosslinked alkylmethacrylate polymer molded article of the present invention (hereinafter sometimes simply referred to as "molded article")
Has a characteristic that the α-dispersion peak temperature of loss elastic modulus (E ″) in its dynamic viscoelastic characteristics (hereinafter sometimes simply referred to as “α” α-dispersion peak temperature ”) is 100 ° C. or higher. Must be present [characteristic (i) above]. Loss modulus (E ") in dynamic viscoelastic properties
When the α-dispersion peak temperature is less than 100 ° C., the mold releasability from the molding die becomes poor during the production of the crosslinked alkyl methacrylate polymer molded article, resulting in a decrease in workability during molding and a decrease in productivity. . From the standpoint of improving the mold releasability of molded products, E ”of crosslinked alkyl methacrylate polymer molded products
The α-dispersion peak temperature of is more preferably 108 ° C. or higher. The upper limit of the E ″ α dispersion peak temperature of the crosslinked alkyl methacrylate-based polymer molded article is not particularly limited, but in reality, due to the rise of the E ″ α dispersion peak temperature,
The peak of tan δ decreases and the storage elastic modulus in the rubbery flat region at 160 ° C. increases, so that it is preferably 115 ° C. or less.

The E "α-dispersion peak temperature of the crosslinked alkyl methacrylate polymer molded article is generally low as the proportion of the linear polymer portion in the molded article increases and as the crosslink density in the molded article decreases. Therefore, by adjusting the use ratio of the linear alkyl methacrylate-based polymer and / or the cross-linking agent used in the production of the cross-linked alkyl methacrylate-based polymer molded article, the α of E ″ of the cross-linked alkyl methacrylate-based polymer molded article can be adjusted. The dispersion peak temperature can be 100 ° C. or higher. In addition, E ″ of cross-linked alkyl methacrylate-based polymer moldings
The α-dispersion peak temperature of is a temperature related to the glass transition point of the molded product, and generally, the higher the glass transition point, the higher the α-dispersion peak temperature. The α-dispersion peak temperature of E ″ of the crosslinked alkylmethacrylate polymer molded article in the present invention is generally measured as follows, and the details thereof are as described in the section of Examples below.

[Measurement method of α dispersion peak temperature of E "of molded article] It is measured by a dynamic mechanical thermal analysis method (DMTA method), that is, modes such as bending, shearing, and tensioning (in the present invention, bending) Mode), a sinusoidal stress is applied to the sample and the loss modulus E ″ of the sample is measured as a function of temperature to determine its peak temperature, where the loss modulus E ″ is the energy lost by internal motion. The corresponding viscous response.

Further, the crosslinked alkyl methacrylate polymer molded article of the present invention has a t in its dynamic viscoelastic property.
It is necessary to have a characteristic that the peak value of an δ (hereinafter sometimes simply referred to as “peak value of tan δ”) is 0.8 or more [the above characteristic (ii)]. When the peak value of tan δ of the molded product is less than 0.8, when the molded product such as a plate is bent by heating and cooled, the cooling distortion of the bent product becomes large and the impact resistance becomes high. The cracks and damages are likely to occur in the bent portion and its vicinity, and it is not possible to obtain a bent product having excellent durability.
It is more preferable that the peak value of tan δ of the molded product is 0.9 or more from the viewpoint of improving bendability. The upper limit of the peak value of tan δ is not particularly limited, but generally tan δ
It is practical that ta has a peak value of 1.3 or less.
Increasing the peak value of nδ lowers the α-dispersion peak temperature of E ″, which is preferable.

The peak value of tan δ of the crosslinked alkyl methacrylate polymer molded article generally increases as the proportion of the linear polymer portion in the molded article increases and as the crosslink density in the molded article decreases. The peak value of tan δ of the crosslinked alkylmethacrylate-based polymer molded article is adjusted to 0 by adjusting the use ratio of the linear alkylmethacrylate-based polymer and / or the crosslinking agent used for producing the crosslinked alkylmethacrylate-based polymer molded article. It can be 8 or more. The peak value of tan δ of the crosslinked alkylmethacrylate polymer molded article in the present invention is measured as follows, and the details thereof are as described in the section of Examples below.

[Measurement method of peak value of tan δ of molded product]
It is measured by a dynamic mechanical thermal analysis method (DMTA method).
That is, a sinusoidal stress is applied to a sample in a mode such as bending, shearing, and tensioning (bending mode in the present invention), the tangent of the loss angle of the sample, that is, tan δ is measured as a function of temperature, and the peak value is obtained. Where t
an δ is a dimensionless number and is equal to the ratio of the loss elastic modulus to the storage elastic modulus per cycle.

The crosslinked alkylmethacrylate polymer molded article of the present invention must have the characteristic that the storage elastic modulus at the rubbery flat region of 160 ° C. is 30 MPa or less [the above-mentioned characteristics. (Iii)]. Storage elastic modulus of the crosslinked alkylmethacrylate-based polymer molded article at a rubber-like flat area of 160 ° C (hereinafter simply referred to as "160 ° C").
Storage elastic modulus "at 30)) exceeds 30 MPa, the releasability of the molded product from the mold becomes poor,
The workability and productivity at the time of manufacturing the molded product deteriorate, and when the molded product having a plate shape is bent under heating and cooled, the cooling distortion becomes large and the impact resistance deteriorates, causing bending. Cracks and breakage easily occur at the part and its vicinity, and it becomes impossible to obtain a bent product having excellent durability. The storage modulus of the molded product at 160 ° C. is preferably 25 MPa or less from the viewpoints of the above-described molded product releasability, bending workability and the like. The lower limit of the storage elastic modulus of the molded product at 160 ° C. is not particularly limited, but in practice, the rubber-like flat region 160
Since the α-dispersion peak temperature of E ″ decreases due to the decrease in the storage elastic modulus at ° C, it is preferably 10 MPa or more. In the present invention, the storage elastic modulus at 160 ° C of the crosslinked alkylmethacrylate polymer molded article is measured as follows, and details thereof are as described in the section of Examples.

[Measurement Method of Storage Elastic Modulus at 160 ° C. in Rubbery Flat Region of Molded Article] Dynamic mechanical thermal analysis method (DMTA
Method). That is, a sinusoidal stress is applied to a sample in modes such as bending, shearing, and tensioning (bending mode in the present invention), the storage elastic modulus of the sample is measured as a function of temperature, and the storage elastic modulus in the rubber-like flat region of 160 ° C. is measured. Find the rate. Here, the storage elastic modulus is an elastic response and corresponds to a completely recoverable energy.

The crosslinked alkylmethacrylate polymer molded article of the present invention is required to simultaneously have the above-mentioned three characteristics (i) to (iii). Even if any one of them is missing, bending work is required. It is not possible to obtain a molded product that is excellent in the properties, resistance to cooling distortion (impact resistance) in a bent product, and releasability from the mold.

The crosslinked alkylmethacrylate polymer molded product of the present invention preferably has a cooling strain of 80 kg / cm ² or less when heated by 10% at 130 ° C., and the cooling strain of the molded product is 80 kg. / Cm ² or less, when a plate-shaped molded product is bent under heating, cooling distortion in the bent product after cooling is reduced, impact resistance is improved, and the bent part and its It is even more difficult for cracks and damage to occur in the vicinity. Here,
"Cooling strain at 10% heat deformation at 130 ° C"
Is measured as follows.

[Measurement Method of Cooling Strain at 10% Heat Deformation of Molded Product at 130 ° C.] One side of the molded product is fixed with a fixed clamp, and the other side is fixed with a pullable clamp connected to a load cell and heated. Sample temperature is 130 in the furnace
Heat to constant temperature. Then, it is deformed by pulling with a movable clamp until it becomes 110% of the initial sample length. Then, the stress applied to the load cell at the time when the sample temperature is 50 ° C. by allowing to cool naturally is defined as the cooling strain.

The crosslinked alkylmethacrylate polymer molded article of the present invention is a crosslinked alkylmethacrylate polymer molded article containing an inorganic filler, and at the same time has the above-mentioned characteristics (i) to (iii). Any product may be used, the composition of the polymer raw material for producing a molded product, the type of crosslinking agent, the content of the type of inorganic filler, the content of each component and the mixing method, the polymerization method, the crosslinking method, The molding method and molding conditions are not particularly limited, but among them,
The crosslinked alkylmethacrylate polymer molded article of the present invention can be smoothly produced by the method described below.

That is, the crosslinked alkylmethacrylate polymer molded article of the present invention is a partially crosslinked alkylmethacrylate gel polymer (A); and an alkylmethacrylate syrup (B) containing an alkylmethacrylate polymer and a crosslinking agent. It can be manufactured by using a molding material in which at least one of them is mixed with an inorganic filler (C), and molding and curing under heating.

In this case, the partially crosslinked alkylmethacrylate gel polymer (A) may be alkylmethacrylate alone; an α, β-ethylenically unsaturated monomer mixture containing alkylmethacrylate as a main component; and alkyl. Polymer raw material selected from alkyl methacrylate-based syrup obtained by dissolving methacrylate homopolymer or alkyl methacrylate-based copolymer in alkyl methacrylate or in α, β-ethylenically unsaturated monomer mixture containing alkyl methacrylate as a main component (A ₁ )
A mixture obtained by partially polymerizing and / or crosslinking a mixture containing a crosslinking agent (A ₂ ) is preferably used.

The above-mentioned alkyl methacrylate syrup (B) is an alkyl methacrylate homopolymer or a copolymer of an alkyl methacrylate mainly composed of an alkyl methacrylate unit and another α, β-ethylenically unsaturated monomer. Α mainly consisting of or in alkyl methacrylate,
A syrup mixture of the syrup (B ₁ ) and the crosslinking agent (B ₂ ) dissolved in the β-ethylenically unsaturated monomer mixture is preferably used.

In the above, in the polymer raw material (A ₁ ) and the syrup (B ₁ ), the molar amount of all the monomers used in their preparation (that is, the polymer, the monomer mixture and / or the syrup) is used. From the viewpoint of weather resistance, it is preferable that the use ratio of the alkyl acrylate is 50 mol% or more based on the total molar amount of all monomers used for formation).
More preferably, it is at least 60 mol%. In this case, as the alkyl methacrylate preferably used,
Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate,
Examples thereof include butyl methacrylate, and these alkyl methacrylates may be used alone or in combination of two or more. Among them, methyl methacrylate is particularly preferably used.

In the above, when another α, β-ethylenically unsaturated monomer is used together with alkylmethacrylate for the preparation of the polymer raw material (A ₁ ) and / or syrup (B ₁ ), the other α , Β-ethylenically unsaturated monomers, whether in the form of monomers or in the form of copolymers with alkyl methacrylate, the other α,
The proportion of the β-ethylenically unsaturated monomer is preferably not more than 50 mol% based on the total molar amount of the alkyl methacrylate and the other α, β-ethylenically unsaturated monomer,
It is preferably at most 40 mol%.

Other α, β-ethylenically unsaturated monomers which can be used in combination with the alkyl methacrylate include, for example, alkyl methacrylates other than the alkyl methacrylate used as the main component (for example, when methyl methacrylate is used as the main component). Is ethyl methacrylate, n
-Propyl methacrylate, isopropyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, cyclohexyl methacrylate, etc.); alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, cyclohexyl acrylate; Hydroxyalkyl (meth) acrylates such as ethyl methacrylate, 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 2-hydroxy-3-chloropropyl methacrylate, and 2-hydroxy-3-chloropropyl acrylate; acrylic Acid; methacrylic acid; metal (meth) acrylate Mention may be made of vinyl toluene, maleic anhydride, vinyl chloride, vinyl acetate; Akurironitoniru; acrylamide; styrene, styrene monomers such as α- methylstyrene. Even when only one of these monomers is used in combination with alkyl methacrylate,
Alternatively, two or more kinds may be used in combination with the alkyl methacrylate.

Alkyl methacrylate containing an alkyl methacrylate homopolymer or an alkyl methacrylate copolymer as a polymer raw material (A ₁ ) for forming the above-mentioned partially crosslinked alkyl methacrylate gel polymer (A). When the syrup (B ₁ ) is used, the viscosity is 0.
It is preferable to use a syrup having a range of 1 to 50 poise and having a content of the alkyl methacrylate homopolymer and / or the alkyl methacrylate copolymer in the syrup of 3 to 70% by weight based on the total weight of the syrup. A syrup having a content of the homopolymer and / or the copolymer of 20 to 45% by weight is more preferably used.

The above-mentioned partially crosslinked alkyl methacrylate gel polymer (A) and / or alkyl methacrylate syrup (B) is necessary for the purpose of improving impact resistance of the crosslinked alkyl methacrylate polymer molded article. According to the above, an addition polymerization block copolymer may be contained. As the addition polymerization type block copolymer in this case, an elastomer having rubber properties is preferably used. For example, a polymer block mainly composed of an aromatic vinyl compound unit and a hydrogenated 1,2-bond amount of 30 are used. % Of a polybutadiene block, a hydrogenated polyisoprene block, a hydrogenated polybutadiene block having a 1,2-bond content of 30 to 80%, and a hydrogenated isoprene /
A block copolymer composed of at least one polymer block II selected from the group consisting of butadiene copolymer blocks can be used. When the addition polymerization type block copolymer as described above is used, the amount thereof is adjusted to the weight [(A) of the partially crosslinked alkyl methacrylate type gel polymer (A) and / or the alkyl methacrylate type syrup (B). When both of (B) are used, the total weight] is set to about 0.2 to 5% by weight based on the effect of improving impact resistance and the bending portion of the crosslinked alkylmethacrylate polymer molded article. It is preferable in terms of prevention of whitening.

The cross-linking agent (A ₂ ) used for the preparation of the partially cross-linked alkyl methacrylate gel polymer (A) and the cross-linking agent (B ₂ ) used for the preparation of the alkyl methacrylate syrup (B) are intramolecular. At least 2
Monomers having two (meth) acryloyl groups are preferably used. More specifically, for example, 1,3-propylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,3-butylene glycol dimethacrylate, dimethylolethane dimethacrylate,
1,1-dimethylolpropane dimethacrylate, 2,
2-dimethylolpropane dimethacrylate, trimethylolethanetri (meth) acrylate, trimethylolpropanetri (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolmethanedi (meth) acrylate, ethylene glycol di (meth) acrylate Acrylate, diethylene glycol di (meth) acrylate, neopentyl glycol dimethacrylate, tetraethylene glycol dimethacrylate,
2,2-bis [4- (methacryloxyethoxy) phenyl] propane, 2,2-bis [4- (methacryloxypentenoxy) phenyl] propane, 1,4-bis (methacryloyloxymethyl) cyclohexyldi (meth ) Acrylate and the like, and these crosslinking agents can be used alone or in combination of two or more.
Among the above, neopentyl glycol dimethacrylate, 1,4-bis (methacryloyloxymethyl)
Cyclohexyl di (meth) acrylate is preferably used because it can achieve both weather resistance and moldability.

The amount of the crosslinking agent (A ₂ ) used is 5 to 10 parts by weight based on 100 parts by weight of the polymer raw material (A ₁ ) used for preparing the partially crosslinked alkyl methacrylate gel polymer (A).
It is preferable that the amount be part by weight, and it is preferable that the amount be 6 to 9 parts by weight. The amount of the crosslinking agent (B ₂ ) to be used is preferably 5 to 10 parts by weight, and more preferably 6 to 9 parts by weight based on 100 parts by weight of the syrup (B ₁ ) used for preparing the alkyl methacrylate syrup (B). It is preferably in parts by weight. The amount of the cross-linking agent (A ₂ ) or cross-linking agent (B ₂ ) used is 5
If the amount is less than the amount by weight, the E "α dispersion peak temperature in the dynamic viscoelastic properties of the crosslinked alkylmethacrylate polymer molded article tends to be lower than 100 ° C, and therefore the moldability of the molded article from the mold is reduced. On the other hand, the amount of the cross-linking agent (A ₂ ) or the cross-linking agent (B ₂ ) used is 1 above.
If it exceeds 0 parts by weight, the peak value of tan δ in the dynamic viscoelastic properties of the crosslinked alkylmethacrylate polymer molded article will be lower than 0.8, and the rubber-like flat region 16
The storage elastic modulus at 0 ° C. tends to be higher than 30 MPa, so that the bending workability of the molded product under heating is deteriorated, and the impact resistance is likely to be deteriorated.

Further, in the partially crosslinked alkylmethacrylate gel polymer (A) and the alkylmethacrylate syrup (B), the content of the linear polymer contained therein is 20 to 40% by weight [partially crosslinked alkyl]. In the case of producing a crosslinked alkylmethacrylate-based polymer molded article using both the methacrylate-based gel polymer (A) and the alkylmethacrylate-based syrup (B), it is preferable that It is more preferably 35% by weight. When the content of the linear polymer is less than 20% by weight as described above, tan δ in the dynamic viscoelastic property of the crosslinked alkyl methacrylate polymer molded article.
Of the molded product tends to be smaller than 0.8, and the storage elastic modulus value in the rubber-like flat region of 160 ° C. of the molded product is 3
It tends to be higher than 0 PMa, whereby the bending workability under heating is deteriorated, the strain in the cooled bending work product becomes large, and the impact resistance tends to be poor. On the other hand, the content of the linear polymer is 40% by weight as described above.
If it exceeds the limit, the loss elastic modulus (E ″) in the dynamic viscoelastic properties of the crosslinked alkyl methacrylate polymer molded article
The α-dispersion peak temperature of is lower than 100 ° C., the mold releasability from the mold tends to be poor, and the molten syrup has a high viscosity, which makes it difficult to prepare the syrup itself.
Problems such as reduced fluidity and reduced handleability and moldability tend to occur.

The partially crosslinked alkylmethacrylate gel polymer (A) can be produced, for example, by the method described in JP-A-60-202128. That is, a mixture containing the above-mentioned polymer raw material (A ₁ ) and the crosslinking agent (A ₂ ) is added to, for example, a low-temperature active polymerization initiator and heated to a relatively low temperature (generally about 30 to 80 ° C.). By partially polymerizing the polymer raw material (A ₁ ). At that time, the kind of the low temperature active polymerization initiator is not particularly limited, and for example, 2,2′-
Azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), acetylcyclohexylsulfonyl peroxide, isobutyryl peroxide, cumyl peroxy neodecanoate , Diisopropyl peroxydicarbonate, di-n-propylperoxydicarbonate, dimyristyl peroxycarbonate, di- (2-
Ethoxyethyl) peroxydicarbonate, di- (methoxyisopropyl) peroxydicarbonate, di-
(2-ethylhexyl) peroxydicarbonate etc. can be mentioned.

When a mixture containing the polymer raw material (A ₁ ) and the cross-linking agent (A ₂ ) is partially polymerized in the presence of a polymerization initiator, a partially cross-linked alkyl methacrylate gel polymer is produced. As long as the polymer content does not exceed 80% by weight, the content of the polymer in the mixture of the polymer raw material (A ₁ ) and the crosslinking agent (A ₂ ) is 4 to 65% by weight, more preferably 10% by weight. Partial crosslinking is preferably carried out in an increase of 60% by weight, most preferably 20-65% by weight.

In the production of the partially crosslinked alkylmethacrylate gel polymer, a low temperature active polymerization initiator and a high temperature active polymerization initiator are added to the polymer raw material (A ₁ ) to carry out the low temperature active polymerization. The initiator is activated but the high temperature active polymerization initiator is heated to a temperature at which it is not activated to form a partially crosslinked alkylmethacrylate gel polymer, and the resulting partially crosslinked alkylmethacrylate gel polymer is obtained. It may be used to perform molding at the activation temperature of a high-temperature active polymerization initiator to produce a heat-cured molded product.

The type of the inorganic filler (C) contained in the crosslinked alkylmethacrylate polymer molded article of the present invention is not particularly limited, but aluminum hydroxide, magnesium hydroxide, calcium carbonate, silica, frit glass, etc. Is preferably used, and aluminum hydroxide and / or frit glass is more preferably used from the viewpoint that a molded product having excellent transparency and a clear color tone can be obtained.

The amount of the inorganic filler added is 100 parts by weight of the partially crosslinked alkyl methacrylate gel polymer (A) and / or the alkyl methacrylate syrup (B) [(A) and (B) in combination. Is the total weight of both 1
00 parts by weight], it is preferably 30 to 200 parts by weight, and more preferably 60 to 150 parts by weight. When the amount of the inorganic filler added is less than 30 parts by weight, the volumetric shrinkage due to polymerization becomes large and the dimensional stability of the molded product tends to be poor, while when it exceeds 200 parts by weight, the mechanical strength of the molded product decreases. It is easy to become a thing that did.

Further, the crosslinked alkylmethacrylate polymer molded article of the present invention may have other coloring agents such as dyes and pigments, resin granules, pattern materials such as natural stone granules, organic staple fibers, etc. for the purpose of enhancing designability. The above-mentioned fillers, other resins of different types, etc. can be added within a range that does not impair the object of the present invention.

The method for producing the crosslinked alkyl methacrylate polymer molded article of the present invention is not particularly limited, and any method can be adopted as long as it can produce a molded article having the above-mentioned characteristics (i) to (iii). For example, when a molded article is produced using the above-mentioned partially crosslinked alkylmethacrylate gel polymer (A), the partially crosslinked alkylmethacrylate gel polymer (A) is mixed with an inorganic filler (C),
Partially cross-linked alkyl methacrylate gel polymer (A)
If does not contain a polymerization initiator that is active at the molding temperature, add a polymerization initiator, kneading at a temperature lower than the activation temperature of the polymerization initiator to prepare a semi-cured molding material, A crosslinked alkylmethacrylate-based polymer molded article can be obtained by placing it in a molding die and curing it by heating.

When a molded article is produced using both the partially crosslinked alkyl methacrylate gel polymer (A) and the alkyl methacrylate syrup (B), the gel polymer (A) and the syrup ( B) and the inorganic filler (C) are mixed, and when the gel polymer (A) and / or the syrup (B) does not contain a polymerization initiator which is active at the molding temperature, a polymerization initiator is added. Addition, mixing or kneading at a temperature lower than the activation temperature of the polymerization initiator to prepare a liquid or semi-cured molding material, which is put in a molding die and heat-cured to form a crosslinked alkyl methacrylate polymer. A molded product can be obtained.

When a molded product is produced using only the alkyl methacrylate syrup (B) as the polymer raw material, the alkyl methacrylate syrup (B) containing the alkyl methacrylate polymer and the crosslinking agent is added to the inorganic filler. A crosslinked alkylmethacrylate-based polymer molded article can be obtained by mixing (C) and a polymerization initiator to prepare a liquid or pace-like molding material, and placing the molding material in a molding die and curing it by heating.

In addition to the above-mentioned method, alkyl methacrylate or a mixture of α, β-ethylenically unsaturated monomers mainly composed of alkyl methacrylate, alkyl methacrylate homopolymer and / or alkyl methacrylate copolymer, cross-linking Agent, an inorganic filler and a polymerization initiator are mixed as they are without undergoing the formation of syrup and kneaded at a temperature lower than the activation temperature of the polymerization initiator to directly prepare a molding material, which is then molded into a molding die. A method of producing a crosslinked alkylmethacrylate-based polymer molded product by putting it in and heating and curing may be adopted.

Further, as still another method, alkyl methacrylate or a mixture of α, β-ethylenically unsaturated monomers mainly containing alkyl methacrylate, alkyl methacrylate homopolymer and / or alkyl methacrylate copolymer, crosslinking agent And the inorganic filler is mixed and kneaded as it is without undergoing the formation of syrup, and then a polymerization initiator is added to the mixture and further kneaded at a temperature lower than the activation temperature of the polymerization initiator to prepare a molding material, which is then molded. A method of producing a crosslinked alkylmethacrylate-based polymer molded article by placing the material in a molding die and curing it by heating may be adopted.

In any of the above-mentioned methods, the preparation of the molding material (mixing of the raw materials) may be carried out by using a conventionally known mixing device and / or kneading device, and there is no particular limitation. Low speed kneader such as kneader,
It can be carried out using a high-speed stirrer such as a disper, a screw type kneader, a kneading roll and the like.

The molding may be carried out by selecting a method suitable for the properties of the molding material from the molding methods conventionally used for molding thermosetting resins.
The molding method is not particularly limited, and for example, compression molding method, cast molding method, transfer molding method, injection molding method and the like can be adopted for molding. When a molded article is manufactured by using two or three or more polymerization initiators having different activation temperatures as the polymerization initiator to be contained in the molding material and molding under heating, the molded article has a large thickness. Also in this case, for example, a cured product is not significantly different between the end portion and the central portion of the molded product, and a molded product having excellent uniformity in terms of mechanical strength and appearance can be obtained, which is preferable.

When the crosslinked alkylmethacrylate polymer molded article is manufactured by the above method,
The content of the linear polymer, the content of the cross-linking agent, the content of the inorganic filler, etc. in the polymer raw material should be selected to be suitable for each situation from the above-mentioned preferable range. According to the above, the peak temperature of E ″ in the dynamic viscoelastic property is 100 ° C. or higher, the peak value of tan δ in the dynamic viscoelastic property is 0.8 or higher, and the storage elastic modulus in the rubbery flat region 160 ° C. is 30 MPa or lower. The crosslinked alkylmethacrylate-based polymer molded article of the present invention having the characteristics (i) to (iii) can be smoothly obtained.

The shape, structure, dimensions, etc. of the crosslinked alkyl methacrylate polymer molded article of the present invention are not particularly limited,
It can be determined according to the purpose of use or purpose. Among them, the crosslinked alkylmethacrylate polymer molded article of the present invention is excellent in bending workability under heating and can be bent to be smoothly manufactured into a desired product. It is desirable that it is a product. In that case, if the plate thickness of the molded product is 3 mm or less, the thermal conductivity becomes good, the heating is uniformly performed during the bending process, and the internal residual strain in the bending process product becomes further smaller, and the resistance is improved. The impact resistance is improved, and the occurrence of cracks and breakage in the bent portion and its vicinity is better prevented.

The crosslinked alkylmethacrylate polymer molded article of the present invention makes use of the characteristics such as good bending workability, good impact resistance, transparency and clear color tone as described above.
For example, it can be effectively used for a wide range of purposes including interior materials and equipment for homes such as system kitchen tops, doors, walls, vanity tops, unit bath waist walls, aprons, bay window counters, etc. be able to.

[0047]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. In addition,
In the following examples, the gel fraction of the partially crosslinked alkyl methacrylate gel polymer, the releasability at the time of molding, the α dispersion peak temperature of the loss elastic modulus (E ″) in the dynamic viscoelastic property of the molded product, the dynamic Peak value of tan δ in viscoelastic property,
The storage elastic modulus and cooling strain in the rubber-like flat region at 160 ° C., and the bending workability of the molded product were measured and evaluated as follows. Further, the polymers, compounds and inorganic fillers used in Example 2 and Comparative Examples 1 to 4 below are all the same products as used in Example 1.

(1) Gel Fraction of Partially Crosslinked Alkyl Methacrylate-based Gel Polymer: Partially crosslinked alkylmethacrylate-based gel polymer obtained in the following example was used as a small piece of 2 mm or less, and a predetermined amount thereof was sampled. Then, its weight (x) is measured, and this is put into acetone containing not more than 2% of hydroquinone, and the mixture is mixed with a Soxhlet extractor to obtain 5
Extract for 10 hours at 0 ° C. Then, the residue in acetone was taken out, dried at 80 ° C. for 24 hours under a reduced pressure of −750 mmHg, and its weight (y) was measured, and the gel content of the partially crosslinked alkyl methacrylate gel polymer was calculated from the following formula. Find the rate.

[0049]

## EQU1 ## Gel fraction (%) = (y / x) × 100

(2) Releasability at the time of molding: In the following examples, when the molded product was taken out smoothly from the mold without cracking or damage, the result was ◯ (good), and the molded product separated from the mold. The case where it was difficult to cause cracking or breakage when taking out from the mold was evaluated as x (poor).

(3) α-dispersion peak temperature of loss elastic modulus (E ") in dynamic viscoelastic property of molded product: molded product obtained in the following example (length 1200 mm, width 2500 mm, thickness 2 m)
m) is cut into a length of 50 mm, a width of 1.5 mm, and a thickness of 2 mm, and a dynamic viscoelasticity measuring device (“PL-DMTA” manufactured by Polymer Laboratories) is used to raise the temperature at the center of the sample under the following conditions. A bending sinusoidal stress was applied to, and the loss elastic modulus E ″ was measured as a function of temperature from the ratio of the out-of-phase stress component to the strain amplitude, and the α dispersion peak temperature of E ″ was obtained. Measurement condition Measurement frequency: 1 Hz Dynamic strain amount: 32 μm Measurement mode: Dual Canti drive clamp: Knife Edge 5 mm Width frame length: 16 mm Measurement temperature: 30 to 250 ° C. Temperature rising condition: 3 ° C./min

(4) t in the dynamic viscoelastic property of the molded product
Peak value of an δ: Molded product (longitudinal 12
00mm, width 2500mm, thickness 2mm) length 50m
m, width 1.5 mm, thickness 2 mm, and a dynamic viscoelasticity measuring device (“PL-DMT” manufactured by Polymer Laboratories)
A ”), a sinusoidal stress of bending is applied to the center of the sample in the longitudinal direction under the following conditions, and the ratio of the loss elastic modulus to the storage elastic modulus per cycle is calculated as a function of temperature ta.
nδ was measured to find the peak value of tanδ. Measurement condition Measurement frequency: 1 Hz Dynamic strain amount: 32 μm Measurement mode: Dual Canti drive clamp: Knife Edge 5 mm Width frame length: 16 mm Measurement temperature: 30 to 250 ° C. Temperature rising condition: 3 ° C./min

(5) Rubber-like flat area of molded product Storage elastic modulus at 160 ° C .: Molded product (longitudinal 12) obtained in the following example
00mm, width 2500mm, thickness 2mm) length 50m
m, width 1.5 mm, thickness 2 mm, and a dynamic viscoelasticity measuring device (“PL-DMT” manufactured by Polymer Laboratories)
A ”), a bending sinusoidal stress is applied to the longitudinal center portion of the sample under elevated temperature under the following conditions, and the storage elastic modulus E ′ is measured as a function of temperature from the ratio of stress components in phase to strain amplitude, The storage elastic modulus in a rubbery flat region at 160 ° C. was obtained. Measurement condition Measurement frequency: 1 Hz Dynamic strain amount: 32 μm Measurement mode: Dual Canti drive clamp: Knife Edge 5 mm Width frame length: 16 mm Measurement temperature: 30 to 250 ° C. Temperature rising condition: 3 ° C./min

(6) Cooling distortion of molded product: Molded product obtained in the following example (length 1200 mm, width 25)
00 mm, thickness 2 mm) is cut into the shape of No. 1 test piece of JIS K7113. After setting the distance between the load cell clamps of the cooling strain measuring device for molded products [Shimazu Seisakusho's stress testing device "Shimadzu Autograph SG-B"] to 100 mm, set the heating furnace for high temperature tensile test and test. A thermocouple is embedded in the same sample (used for temperature control and measurement of the heating furnace) as the piece, and the temperature is raised until the sample temperature reaches 130 ° C. The door of the heating furnace is opened, the test piece is set only in the upper clamp within 1 minute, the door is closed, and the temperature is kept at 130 ° C for about 10 minutes. Open the door of the heating furnace, fix the test piece and the lower clamp within 30 seconds, close the door and keep the temperature at 130 ° C for about 5 seconds.
Hold for minutes. 10 mm of test piece at a pulling speed of 100 mm / min
Pull and hold for 1 minute. The door of the heating furnace is opened and the test piece is naturally cooled. The stress of the load cell at the time when the sample temperature reached 50 ° C. was measured and divided by the cross-sectional area of the test piece to give a test piece of 1 cm ²
Calculate the cooling strain per hit.

(7) Bending workability of molded product: Using the bending workability obtained by bending workability of the molded product in each example, JIA
According to K4401, a falling ball impact test in which a ball is dropped on a bent portion is performed, and the result is visually observed. When there is no crack in the bent portion, it is ○ (good), and when there is a crack. It evaluated as x (defect).

Example 1 (1) 30 parts by weight of linear polymethylmethacrylate having a viscosity average degree of polymerization of 1300 [HR beads manufactured by Kuraray Co., Ltd.], 63.5 parts by weight of methylmethacrylate monomer, addition polymerization block 1 part by weight of a copolymer [“Septon 2002” manufactured by Kuraray Co., Ltd.], 3.4 parts by weight of 1,4-bis (methacryloyloxymethyl) cyclohexyl dimethacrylate [“R604” manufactured by Nippon Kayaku Co., Ltd.], Neopentyl glycol dimethacrylate [Shin Nakamura Chemical Co., Ltd. "N
K esittel NPG-DM "] 2.1 parts by weight to 100 parts by weight of syrup obtained, 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile) 0 as a polymerization initiator .0013 parts by weight, 1,4 (8)-
p-menthadiene (polymerization regulator) 0.003 parts by weight, 2
0.1 parts by weight of-(2'-hydroxy-5'-methylphenyl) benzotriazole (ultraviolet absorber) was added and dissolved to prepare a preparation liquid. (2) The prepared solution obtained in (1) above was poured into a cell assembled with two glass plates at an interval of 20 mm and polymerized at 60 ° C. for 2 hours to give a gel fraction of 15.2%. A partially crosslinked alkyl methacrylate gel polymer was obtained. (3) 120 parts by weight of aluminum hydroxide (average particle size 8 μm), 1,1-based on 100 parts by weight of the partially crosslinked alkyl methacrylate gel polymer obtained in (2) above
0.813 parts by weight of bis (t-butylperoxy) -3,3,5-trimethylcyclohexane [“Trigonox 29-N75” manufactured by Kayaku Aguzo Co., Ltd.], t-butylperoxyisopropyl carbonate [Kayaku Aguzo ( "Kayacarnol BIC-75"] 0.599 parts by weight,
1,3-Bis (t-butylperoxyisopropyl) benzene [“PARCADOX 14” manufactured by Kayaku Aguso Co., Ltd.]
0.430 parts by weight was added to the pressure type kneader [Co., Ltd.].
Moriyama Seisakusho "D1-5"] was stirred and mixed at room temperature for 20 minutes to obtain a semi-cured molding material.

(4) The semi-cured molding material obtained in (3) above was placed on a flat mold of 1250 mm × 2500 mm which was heated to 130 ° C. in advance, and the mold was closed to 10 kg / cm ^2.
After heating for 30 seconds, the pressure was maintained at 100 kg / cm ² for 5 minutes. After cooling the mold to 100 ° C, the contents are taken out, and the length is 1250 mm, the width is 2500 mm, and the thickness is 2
A molded product of mm was obtained. (5) When the dynamic viscoelastic property of the molded product obtained in (4) above was measured, the α ″ peak temperature of E ″ was 1
The peak value of tan δ was 1.19 at 09 ° C., and the E ′ value in the rubbery flat region at 160 ° C. was 13.2 MPa.
Further, when the cooling strain was measured, it was 47.5 kg / cm ^2.
Met. (6) With respect to the molded product obtained in (4) above, a rubber adhesive is applied to the bonding surface of the molded product and the backing material (plywood of 20 mm), and the heating temperature is set to 14 by an iron bender method.
When heat bending with a radius of curvature of 10 mm was performed at 0 ° C., no cracks were found in the product that was bent and cooled. Further, when the bent product obtained here was subjected to a falling ball impact test based on JIS K4401 as described above, no crack was observed.

Example 2 (1) 25 parts by weight of linear polymethyl methacrylate having a viscosity average degree of polymerization of 1300, 67.2 parts by weight of methyl methacrylate monomer, 1 part by weight of addition polymerization block copolymer, 1,4 -Bis (methacryloyloxymethyl) cyclohexyl dimethacrylate 3.4 parts by weight and neopentyl glycol dimethacrylate 3.4 parts by weight were dissolved in 100 parts by weight of syrup, and 2,2'-as a polymerization initiator. Azobis (4-methoxy-2,4-dimethylvaleronitrile) 0.0013 parts by weight, 1,4 (8)-
0.003 parts by weight of p-menthadiene and 0.1 parts by weight of 2- (2′-hydroxy-5′-methylphenyl) benzotriazole were added and dissolved to prepare a preparation liquid. (2) The preparation obtained in (1) above was subjected to the same operations as in Example 1 to obtain a partially crosslinked alkylmethacrylate gel polymer having a gel fraction of 17.7%. (3) 120 parts by weight of aluminum hydroxide and 1,1-bis (t-butylperoxy) -3,3 based on 100 parts by weight of the partially crosslinked alkylmethacrylate gel polymer obtained in (2) above. 0.75 parts by weight of 5,5-trimethylcyclohexane, 0.541 parts by weight of t-butylperoxyisopropyl carbonate, and 0.389 parts by weight of 1,3-bis (t-butylperoxyisopropyl) benzene were added, and the operation was performed. The same pressure type kneader as used in Example 1 was stirred and mixed for 20 minutes at room temperature to obtain a semi-cured molding material.

(4) The semi-cured molding material obtained in (3) above was subjected to the same operations as in Example 1 to obtain a molded product having a length of 1250 mm, a width of 2500 mm and a thickness of 2 mm. (5) When the dynamic viscoelastic property of the molded product obtained in (4) above was measured, the α ″ peak temperature of E ″ was 1
The peak value of tan δ was 1.17 at 10 ° C., and the E ′ value in the rubbery flat region at 160 ° C. was 15.8 MPa.
Moreover, when the cooling strain of the molded product was measured, it was 62.3 kg.
/ Cm ² . (6) With respect to the molded product obtained in the above (4), a backing material was adhered and heating temperature 1 was applied in the same manner as in (6) of Example 1.
When heat bending with a radius of curvature of 10 mm was carried out at 40 ° C., no cracks were found in the bent and cooled product. Further, when the bent product obtained here was subjected to a falling ball impact test based on JIS K4401 as described above, no crack was observed.

Comparative Example 1 (1) 15 parts by weight of linear polymethyl methacrylate having a viscosity average degree of polymerization of 1300, 77.8 parts by weight of methyl methacrylate monomer, 1 part by weight of addition polymerization block copolymer, 1,4 -Bis (methacryloyloxymethyl) cyclohexyl dimethacrylate (3.88 parts by weight) and neopentyl glycol dimethacrylate (2.32 parts by weight) were dissolved in 100 parts by weight of syrup, and 2,2'-azobis (4- 0.0013 parts by weight of methoxy-2,4-dimethylvaleronitrile), 0.003 parts by weight of 1,4 (8) -p-menthadiene, 2- (2'-hydroxy-5 ')
-Methylphenyl) benzotriazole (0.1 part by weight) was added and dissolved to prepare a preparation liquid. (2) The preparation obtained in (1) above was subjected to the same operations as in Example 1 to obtain a partially crosslinked alkyl methacrylate gel polymer having a gel fraction of 19.0%. (3) Aluminum hydroxide, 1,1-bis (t-butylperoxy) -based on 100 parts by weight of the partially crosslinked alkyl methacrylate gel polymer obtained in (2) above.
0.872 parts by weight of 3,3,5-trimethylcyclohexane, 0.642 parts by weight of t-butylperoxyisopropyl carbonate and 0.462 parts by weight of 1,3-bis (t-butylperoxyisopropyl) benzene were added. Then
The same pressure kneader as used in Example 1 was stirred and mixed at room temperature for 20 minutes to obtain a semi-cured molding material.

(4) The semi-cured molding material obtained in (3) above was subjected to the same operations as in Example 1 to obtain a molded product having a length of 1250 mm, a width of 2500 mm and a thickness of 2 mm. (5) When the dynamic viscoelastic property of the molded product obtained in (4) above was measured, the α ″ peak temperature of E ″ was 1
The peak value of tan δ was 0.78 at 12 ° C., and the E ′ value in the rubbery flat region at 160 ° C. was 31.6 MPa.
In addition, the measured cooling strain of the molded product was 81.9 kg.
/ Cm ² . (6) With respect to the molded product obtained in the above (4), a backing material was adhered and heating temperature 1 was applied in the same manner as in (6) of Example 1.
When heat bending was performed at 40 ° C. with a radius of curvature of 10 mm, cracks were already observed in the bent portion of the bent and cooled product.

Comparative Example 2 (1) 30 parts by weight of linear polymethylmethacrylate having a viscosity average degree of polymerization of 1300, 59.5 parts by weight of methyl methacrylate monomer, 1 part by weight of addition polymerization block copolymer, 1,4 -Bis (methacryloyloxymethyl) cyclohexyl dimethacrylate 4.76 parts by weight, neopentyl glycol dimethacrylate 4.76 parts by weight to 100 parts by weight of the syrup obtained, 2,2'- as a polymerization initiator Azobis (4-methoxy-2,4-dimethylvaleronitrile) 0.0013 parts by weight, 1,4 (8)
0.003 parts by weight of -p-menthadiene and 0.1 parts by weight of 2- (2'-hydroxy-5'-methylphenyl) benzotriazole were added and dissolved to prepare a preparation liquid. (2) The preparation obtained in (1) above was subjected to the same operation as in Example 1 to obtain a partially crosslinked alkylmethacrylate gel polymer having a gel fraction of 18.6%. (3) 120 parts by weight of aluminum hydroxide, 1,1-bis (t-butylperoxy) -3,3,3, based on 100 parts by weight of the partially crosslinked alkylmethacrylate gel polymer obtained in (2) above. 5-trimethylcyclohexane-
N75) 0.607 parts by weight, t-butylperoxypropyl carbonate 0.447 parts by weight, 1,3-bis (t-butylperoxyisopropyl) benzene 0.3
21 parts by weight was added, and the mixture was stirred and mixed at room temperature for 20 minutes with the same pressure type kneader used in Example 1 to obtain a semi-cured molding material.

(4) The semi-cured molding material obtained in (3) above was subjected to the same operations as in Example 1 to obtain a molded product having a length of 1250 mm, a width of 2500 mm and a thickness of 2 mm. (5) When the dynamic viscoelastic property of the molded product obtained in (4) above was measured, the α ″ peak temperature of E ″ was 1
The peak value of tan δ was 0.76 at 11 ° C., and the E ′ value in the rubbery flat region at 160 ° C. was 32.4 MPa.
Moreover, when the cooling strain of the molded product was measured, it was 84.5 kg.
/ Cm ² . (6) With respect to the molded product obtained in (4) above, a backing material was adhered in the same manner as in (6) of Example 1, and the curvature radius was 10 m at a heating temperature of 140 ° C. by an iron bender method.
When heat bending of m was performed, cracks were already observed in the bent portion of the bent product that was cooled after bending.

Comparative Example 3 (1) 30 parts by weight of linear polymethylmethacrylate having a viscosity average degree of polymerization of 1300, 66.2 parts by weight of a methylmethacrylate monomer, 1 part by weight of an addition polymerization block copolymer, 1,4 -2,2'-azobis (4-) relative to 100 parts by weight of syrup obtained by dissolving 1.4 parts by weight of bis (methacryloyloxymethyl) cyclohexyldimethacrylate and 1.4 parts by weight of neopentylglycol dimethacrylate. Methoxy-2,4-dimethylvaleronitrile)
0.0013 parts by weight, 0.003 parts by weight of 1,4 (8) -p-menthadiene, 0.1 parts by weight of 2- (2'-hydroxy-5'-methylphenyl) benzotriazole were added and dissolved to prepare a preparation liquid. Was prepared. (2) The preparation obtained in (1) above was subjected to the same operations as in Example 1 to obtain a partially crosslinked alkylmethacrylate gel polymer having a gel fraction of 17.0%. (3) 120 parts by weight of aluminum hydroxide, 1,1-bis (t-butylperoxy) -3,3,3, based on 100 parts by weight of the partially crosslinked alkylmethacrylate gel polymer obtained in (2) above. Example 1 was added with 0.773 parts by weight of 5-trimethylcyclohexane, 0.568 parts by weight of t-butylperoxyisopropyl carbonate and 0.408 parts by weight of 1,3-bis (t-butylperoxyisopropyl) benzene. The mixture was stirred and mixed in the same pressure type kneader as used in 1 above for 20 minutes at room temperature to obtain a semi-cured molding material.

(4) The semi-cured molding material obtained in (3) above is placed on a flat mold of 1250 mm × 2500 mm which has been heated to 130 ° C. in advance, and the mold is closed to 10 kg / cm ^2.
After heating for 30 seconds, the pressure was maintained at 100 kg / cm ² for 5 minutes. After that, when the mold was cooled to 100 ° C. and the contents were to be taken out, the mold releasability from the mold was poor and the mold could not be taken out smoothly. When it was forcibly taken out, cracking occurred and a regular molded product could not be obtained. . (5) The dynamic viscoelastic property was measured using a part of the cracked molded product obtained in the above (4) as a sample, and the E ″ α dispersion peak temperature was 98 ° C. and tan δ was The peak value was 1.21 and the E ′ value in the rubbery flat region at 160 ° C. was 13.0 MPa.

Comparative Example 4 (1) 20 parts by weight of linear polymethyl methacrylate having a viscosity average degree of polymerization of 1300, 72.8 parts by weight of methyl methacrylate monomer, 1 part by weight of addition polymerization block copolymer, 1,4 -Bis (methacryloyloxymethyl) cyclohexyl dimethacrylate 3.8 parts by weight and neopentyl glycol dimethacrylate 2.37 parts by weight were dissolved in 100 parts by weight of syrup, and 2,2'-azobis (4- Methoxy-2,4-dimethylvaleronitrile)
0.0013 parts by weight, 0.003 parts by weight of 1,4 (8) -p-menthadiene, 0.1 parts by weight of 2- (2'-hydroxy-5'-methylphenyl) benzotriazole were added and dissolved to prepare a preparation liquid. Was prepared. (2) The preparation obtained in (1) above was subjected to the same operation as in Example 1 to obtain a partially crosslinked alkylmethacrylate gel polymer having a gel fraction of 18.5%. (3) 120 parts by weight of aluminum hydroxide and 1,1-bis (t-butylperoxy) -3,3 based on 100 parts by weight of the partially crosslinked alkylmethacrylate gel polymer obtained in (2) above. In Example 1, 0.912 parts by weight of 5,5-trimethylcyclohexane, 0.563 parts by weight of t-butylperoxyisopropyl carbonate and 0.483 parts by weight of 1,3-bis (t-butylperoxyisopropyl) benzene were added. The same pressure type kneader as that used was stirred and mixed at room temperature for 20 minutes to obtain a semi-cured molding material.

(4) The semi-cured molding material obtained in (3) above is placed on a flat mold of 1250 mm × 2500 mm which has been heated to 130 ° C. in advance, and the mold is closed to 10 kg / cm ^2.
After heating for 30 seconds, the pressure was maintained at 100 kg / cm ² for 5 minutes. After cooling the mold to 100 ° C, the contents are taken out, and the length is 1250 mm, the width is 2500 mm, and the thickness is 2
A molded product of mm was obtained. (5) When the dynamic viscoelastic property of the molded product obtained in (4) above was measured, the α ″ peak temperature of E ″ was 1
The peak value of tan δ was 0.85 at 10 ° C., and the E ′ value in the rubbery flat region of 160 ° C. was 31.0 MPa.
Also, the cooling strain of the molded product was measured and was 80.5 kg.
/ Cm ² . (6) With respect to the molded product obtained in (4) above, a backing material is adhered in the same manner as in (6) of Example 1 and bent by an iron bender method at a heating temperature of 140 ° C. and a curvature radius of 10 mm. As a result, cracking was already observed in the bent portion of the product obtained by cooling after bending.

Examples 1 and 2 above and Comparative Example 1
The results of 4 to 4 are summarized in Table 1 below.

[0069]

[Table 1]

From the results of Examples 1 and 2 and Comparative Examples 1 to 4 summarized in Table 1 above, the α dispersion peak temperature of the loss elastic modulus (E ″) in the dynamic viscoelastic property is 100 ° C. or higher. Property (i), tan δ in dynamic viscoelastic property
(Ii) having a peak value of 0.8 or more and a storage elastic modulus at a rubbery flat region of 160 ° C. of 30 MP
In the case of the crosslinked alkylmethacrylate polymer molded articles of Example 1 and Example 2 satisfying the characteristic (iii) that it is a or less, the mold releasability from the mold is good and the molding operation is performed smoothly. In addition, it is excellent in bending workability under heating, no distortion (internal stress) is generated in the bent part after bending, it is excellent in impact resistance and cracking or damage does not occur. Recognize.

On the other hand, the crosslinked alkylmethacrylate-based polymer molded article of Comparative Example 3 in which the E ″ α-dispersion peak temperature is less than 100 ° C. and does not have the characteristic (i) is the mold release from the mold. It was found that the resin had poor properties and could not be taken out smoothly from the mold, and cracking occurred when taken out forcibly, and the peak value of tan δ was less than 0.8, which did not have the characteristic (ii), Moreover, the rubber-like flat area 16
The crosslinked alkylmethacrylate polymer molded articles of Comparative Example 1 and Comparative Example 2 having a storage elastic modulus at 0 ° C. of more than 30 MPa and not having the characteristic (iii), and a storage elastic modulus at a rubbery flat region of 160 ° C. of 30 MPa. All of the crosslinked alkyl methacrylate polymer molded articles of Comparative Example 4 exceeding the above range and having no characteristic (iii) were inferior in bending workability. It can be seen that internal strain is generated and cracks occur when cooled.

[0072]

EFFECTS OF THE INVENTION The crosslinked alkylmethacrylate polymer molded article of the present invention is excellent in mold releasability from the molding die, and therefore can be manufactured with good workability and high productivity. Further, the crosslinked alkylmethacrylate polymer molded article of the present invention is excellent in bending workability, and when bent under heating, internal bending does not occur in the bending work part, and the bending workability is excellent. Since such a bent product does not cause problems such as cracking or damage. In addition, the crosslinked alkylmethacrylate polymer molded article of the present invention has a transparent feeling, has a clear color tone, and has a high-class feeling. Therefore, the crosslinked alkylmethacrylate polymer molded article of the present invention makes use of the above-mentioned characteristics, and makes use of the above-mentioned characteristics such as the top plate of the system kitchen, the door, the wall, the top of the vanity, the waist wall of the unit bath, the apron, and the counter of the bay window. It can be effectively used for a wide range of purposes including interior materials and equipment for houses such as.

Claims (6)

[Claims] 1. A crosslinked alkylmethacrylate polymer molded article containing an inorganic filler, wherein (i) the loss dispersion modulus (E ″) α dispersion peak temperature in the dynamic viscoelastic property is 100 ° C. or higher. (Ii) the peak value of tan δ in the dynamic viscoelastic property is 0.8 or more; and (iii) the storage elastic modulus in the rubber-like flat region at 160 ° C. is 30 MPa or less; iii)
A crosslinked alkylmethacrylate-based polymer molded article, comprising: 2. The α dispersion peak temperature of loss elastic modulus (E ″) in the dynamic viscoelastic property is 108 ° C. or higher, the peak value of tan δ in the dynamic viscoelastic property is 0.9 or higher, and the rubber-like flat region is 160 ° C. The crosslinked alkylmethacrylate polymer molded article according to claim 1, having a storage elastic modulus of 25 MPa or less. 3. The crosslinked alkylmethacrylate polymer molded article according to claim 1, which has a cooling strain of 80 kg / cm ² or less at 10% heat deformation at 130 ° C. 4. A crosslinked alkylmethacrylate polymer molded article is at least one of a partially crosslinked alkylmethacrylate gel polymer (A) and an alkylmethacrylate syrup (B) containing an alkylmethacrylate polymer and a crosslinking agent. Also, the crosslinked alkyl methacrylate polymer molded article according to any one of claims 1 to 3, which is a molded article obtained by heat molding using a molding material containing an inorganic filler (C). 5. The partially crosslinked alkyl methacrylate gel polymer (A) comprises alkyl methacrylate; an α, β-ethylenically unsaturated monomer mixture containing alkyl methacrylate as a main component; and an alkyl methacrylate homopolymer or alkyl. A product obtained by partially polymerizing and / or crosslinking a mixture containing a polymer raw material (A ₁ ) and a crosslinking agent (A ₂ ) when selected from alkyl methacrylate-based syrup containing a methacrylate-based copolymer Wherein the alkyl methacrylate syrup (B) is a homopolymer of alkyl methacrylate or a copolymer of alkyl methacrylate mainly composed of an alkyl methacrylate unit and another α, β-ethylenically unsaturated monomer in the alkyl methacrylate. Or from alkyl methacrylate It becomes as alpha, beta-ethylenically unsaturated monomers by dissolving in a mixture syrup (B ₁₎ and the and the crosslinking agent is a mixed syrup of (B _2), crosslinked alkyl methacrylate polymer molding as claimed in claim 4 Goods. 6. A product obtained by bending the crosslinked alkylmethacrylate polymer molded product according to claim 1.