JP2007291206A - Methacrylic resin shaped article, methacrylic resin laminate, and methods for producing them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a methacrylic resin shaped article providing a product having good impact resistance, and to provide a methacrylic resin laminate and methods for producing them. <P>SOLUTION: The methacrylic resin shaped article comprises a multi-step polymerization copolymer containing a gummy copolymer having a crosslinked structure, and a plurality of nearly spherical island parts (unstained parts) 43b present in a sea part (a stained part) 43a comprising the gummy copolymer. The methacrylic resin laminate using the shaped article and the methods for producing them are also provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a methacrylic resin molded product, a methacrylic resin laminate, and a method for producing them.

Methacrylic resin molded products are widely used in lighting fixtures, signboards, various building materials, sound insulation boards, various display bodies, etc. due to their excellent transparency and surface gloss, as well as good weather resistance and mechanical properties. .
However, there are cases where the impact resistance is insufficient, and a technique for improving the impact resistance by dispersing a substantially particulate rubber-like polymer has been proposed.
Examples of conventionally proposed ones include the following.

A production method by a casting method (casting polymerization method) is disclosed for an impact-resistant composition comprising 4-90 parts by mass of a multistage polymer (rubber-like polymer) containing an elastomer layer in a methacrylic resin (patent) Reference 1).
Further, a graft copolymer obtained by graft-polymerizing a hard resin component to a rubbery copolymer having a crosslinked structure and an average particle diameter of 0.1 to 1 μm with respect to 100 parts by mass of a methyl methacrylate resin. A cast plate in which 2 to 30 parts by mass of the coalescence is dispersed is disclosed (see Patent Document 2).
Further, 5 to 50 parts by mass of a methyl methacrylate polymer having a viscosity average molecular weight of 10,000 to 200,000 is dissolved in 100 parts by mass of a monomer having methyl methacrylate as a main component. (Polymer) A method for producing a methyl methacrylate resin plate in which syrup (viscous liquid) in which 1 to 50 parts by mass are dispersed is cast and polymerized is disclosed (see Patent Document 3).
In addition, a rubber-containing acrylic multi-stage polymer (rubber) in which a micro layer of rubber is separated into a hard core in a thermoplastic acrylic resin and the rubber layer is intermittently surrounded by a plurality of particles. An acrylic resin composition containing 4 to 80 parts by weight of a polymer is disclosed (see Patent Document 4).
Japanese Patent Publication No.55-27576 Japanese Patent No. 2648179 Japanese Patent No. 3508251 JP 11-49922 A

  However, conventional methacrylic resin molded products are not sufficiently effective in improving impact resistance, and further improvements are required.

  Accordingly, an object of the present invention is to provide a methacrylic resin molded article having improved impact resistance, a methacrylic resin laminate using the same, and a method for producing them.

In order to solve the above problems, the present invention proposes the following means.
[1] A methacrylic resin molded article containing a multistage copolymer including a rubbery copolymer having a crosslinked structure,
A methacrylic resin molded product in which a plurality of substantially spherical methacrylic resins are present in a rubbery copolymer.
[2] The methacrylic resin molded product according to [1], wherein the gel content of the entire methacrylic resin molded product is 1.3 times or more of the gel content of the multistage polymerization copolymer.
[3] A rubbery copolymer is obtained by copolymerizing a raw material monomer containing 0.01 to 3 parts by mass of a polyfunctional polymerizable compound in 100 parts by mass of the raw material monomer of the rubbery copolymer. The methacrylic resin molded product according to [1] or [2].
[4] The methacrylic resin molded product according to any one of [1] to [3], wherein the content of the multistage polymerization copolymer is 4 to 30 parts by mass in 100 parts by mass of the methacrylic resin molded product.

[5] A method for producing the methacrylic resin molded article according to any one of [1] to [4],
A step of preparing a mixed solution by mixing a multi-stage polymerization copolymer including a rubbery copolymer having a crosslinked structure and a methyl methacrylate-based raw material;
Pouring the mixture into a mold and curing by casting polymerization;
A method for producing a methacrylic resin molded article having
[6] The step of preparing the mixed solution comprises:
A step of preparing a dispersion (A) by dispersing a multi-stage polymerization copolymer in a methyl methacrylate-based raw material (B-1) containing a radically polymerizable monomer mainly composed of methyl methacrylate;
A methyl methacrylate raw material (B-) containing the dispersion (A) and a polymer of a radical polymerizable monomer mainly containing methyl methacrylate and / or a radical polymerizable monomer mainly containing methyl methacrylate. The method for producing a methacrylic resin molded article according to [5], comprising a step of mixing 2).
[7] The method for producing a methacrylic resin molded article according to [5] or [6], which uses a multistage copolymer recovered by spray drying.

[8] A methacrylic resin laminate having a hard coat film and a layer made of the methacrylic resin molded product according to any one of [1] to [4].

[9] A method for producing the methacrylic resin laminate according to [8],
Forming a hard coat film in the mold;
A step of preparing a mixed solution by mixing a multi-stage polymerization copolymer including a rubbery copolymer having a crosslinked structure and a methyl methacrylate-based raw material;
Pouring the mixed solution into a mold on which the hard coat film is formed, and curing by a casting polymerization method;
A method for producing a methacrylic resin laminate having:
[10] A method for producing the methacrylic resin laminate according to [8],
A pair of endless belts that run facing each other at a predetermined interval; and a pair of gaskets that are provided near both ends of the pair of endless belts and that run following the endless belts. Forming a hard coat film on one or both surfaces of the pair of endless belts in a molding apparatus having a space formed by a pair of gaskets;
A step of preparing a mixed solution by mixing a multi-stage polymerization copolymer including a rubbery copolymer having a crosslinked structure and a methyl methacrylate-based raw material;
Supplying the mixed liquid continuously into the space of the molding apparatus and curing the mixture;
A method for producing a methacrylic resin laminate having:
[11] The step of preparing the mixed solution comprises:
A step of preparing a dispersion (A) by dispersing a multi-stage polymerization copolymer in a methyl methacrylate-based raw material (B-1) containing a radically polymerizable monomer mainly composed of methyl methacrylate;
A methyl methacrylate raw material (B-) containing the dispersion (A) and a polymer of a radical polymerizable monomer mainly containing methyl methacrylate and / or a radical polymerizable monomer mainly containing methyl methacrylate. The method for producing a methacrylic resin laminate according to [9] or [10], comprising a step of mixing 2).
[12] The method for producing a methacrylic resin laminate according to any one of [9] to [11], wherein the multistage copolymer recovered by spray drying is used.

  In the present invention, it is possible to provide a methacrylic resin molded article with improved impact resistance, a methacrylic resin laminate using the same, and a method for producing them.

[Methacrylic resin molded products]
The methacrylic resin molded product of the present invention is a methacrylic resin molded product containing a multi-stage polymerized copolymer including a rubbery copolymer having a crosslinked structure, and a plurality of substantially A spherical methacrylic resin is present.

The presence of a plurality of substantially spherical methacrylic resins in the rubbery copolymer means that when the methacrylic resin molded product is observed with a transmission electron microscope, the sea part of the rubbery copolymer and methacrylic acid This can be confirmed by observing sea-island shades composed of islands of resin.
In this specification, “sea-island shading” refers to a methacrylic resin molded product cut into a film having a thickness of about 80 nm, dyed with a stain such as ruthenium tetroxide, and transmitted electron microscope (TEM). The rubber part in the “rubber-like copolymer” was observed as a dyed “sea part”, and unstained island parts made of methyl methacrylate resin were observed in these parts. It means that the state of being stained is observed by the sea part (rubber part) and the island part (methyl methacrylate resin).
For the methacrylic resin laminates described below, the presence or absence of “sea-island shading” was similarly observed using a sample of a film made of a methacrylic resin molded product with a thickness of about 80 nm. can do.

When a methacrylic resin molded product is cut into a film and dyed and observed with a transmission electron microscope (TEM), for example, a photograph as shown in FIG. 5 is obtained.
Reference numeral 40 denotes a methacrylic resin portion in which a plurality of substantially spherical portions 41 are dotted. In this example, the substantially spherical portion 41 includes a polymer 42 obtained by polymerization of the first stage made of a methacrylic resin, and a portion 43 derived from a rubbery copolymer obtained by subsequent polymerization of the second stage. It has. In addition, since the polymer obtained by the third stage polymerization is not dyed, it is assimilated with the methacrylic resin portion 40 and is not clearly confirmed. In the portion 43 derived from the rubbery copolymer obtained by the second-stage polymerization, the sea portion (dyed portion) 43a and a plurality of substantially spherical island portions (undyed portions) scattered therein. 43b is observed. The sea portion (dyed portion) 43a is made of a rubber-like copolymer, and the island portion (undyed portion) 43b is made of a methacrylate resin.

Such a methacrylic resin molded product can be produced, for example, as follows.
First, the polymer 42 obtained by the first stage polymerization is formed, and then the second stage polymerization is performed to form a rubbery copolymer, preferably using a copolymerizable monomer. Graft polymerization (third stage polymerization) is carried out to form a multistage polymerization copolymer.
And the multistage polymerization copolymer obtained in this way and the methylmethacrylate-type raw material mentioned later are mixed, and this casting liquid is preferably filled in a mold to perform casting polymerization. In addition, when using a polymer as a raw material of the methacrylic resin part 40, the polymer preferably has a mass average molecular weight of 300,000 or less (substantially 50,000 or more).
Then, the rubber-like copolymer of the multistage polymerization copolymer is swollen by the raw material of the methacrylic resin portion 40, and these raw materials enter the rubber-like copolymer. As the polymerization reaction proceeds, these raw materials become substantially spherical, and as shown in FIG. 5, island portions (not yet formed) of methacrylate-based resin scattered in the sea portion (dyed portion) 43a made of a rubbery copolymer. (Stained portion) 43b. As a result, sea-island shades are obtained as shown in FIG.
In order to swell the rubber-like copolymer with the raw material of the methacrylic resin portion 40 in this way and obtain sea-island shade after the polymerization reaction, the rubber-like copolymer constituting the sea portion (dyed portion) 43a is used. It is preferable that the degree of crosslinking of the coalescence is not too high.

The methacrylic resin molded product of the present invention has a multi-core structure in which island portions (undyed portions) 43b formed of methacrylic resin are scattered in sea portions (dyed portions) 43a. Thus, the multi-core part composed of these island parts (undyed parts) 43b plays a role of absorbing the impact. As a result, impact resistance is improved.
Moreover, since the impact absorbing ability of the island portion (undyed portion) 43b is very high, the blending amount of the multistage polymerization copolymer in the methacrylic resin molded product can be reduced. Therefore, the dispersion time when mixing the raw material of the methacrylic resin part 40 and the multistage polymerization copolymer is short, and the production efficiency is very good. Moreover, it is suitable also from the point of cost reduction.
Moreover, a methacrylic resin molded product having excellent transparency can be obtained. In addition, a methacrylic resin molded article having good heat resistance can be obtained.

Hereinafter, the methacrylic resin molded product of the present invention will be described in detail together with an example of its production method.
For example, a methacrylic resin molded article is produced by producing a multi-stage polymerization copolymer including a rubbery copolymer having a crosslinked structure by performing a polymerization reaction,
It can be manufactured by preparing a mixed solution in which a methyl methacrylate raw material and the multistage polymerization copolymer are mixed, and then curing the mixed solution.
The “methyl methacrylate-based material” refers to a material that constitutes the methacrylic resin portion 40 and the island portion (unstained portion) 43b after the above.

<Manufacture of multistage polymerization copolymer>
First, a multistage polymerization copolymer is prepared.
The multistage polymerization copolymer may be obtained by at least two stages of polymerization, and includes a rubbery copolymer having a crosslinked structure obtained by at least one stage of polymerization.
The “gel content of the multistage polymerization copolymer” in [2] indicates the gel content of the raw multistage polymerization copolymer before the production of the methacrylic resin molded article.

Examples of the multistage polymerization copolymer include the following.
A multistage polymerization copolymer obtained by two-stage polymerization including a “methacrylate polymer” obtained by polymerizing a raw material monomer having methyl methacrylate as a main component and a “rubber-like copolymer” having a crosslinked structure.
A multi-stage polymerization copolymer obtained by three-stage polymerization in which the “rubber-like copolymer” and the “methacrylate-type polymer” are sequentially provided after obtaining the “methacrylate polymer”.
-Obtained by four or more stages of polymerization in which the "methacrylate polymer" and the "rubber-like copolymer" having a crosslinked structure are alternately arranged, and the "methacrylate polymer" is arranged by the last stage polymerization. Multistage polymerization copolymer.
The rubbery copolymer can also be formed by two or more stages of polymerization.

  Hereinafter, for convenience, a “methacrylate polymer” is provided by the first stage polymerization, and a “rubber-like copolymer” having a crosslinked structure is provided by the subsequent second stage polymerization. A manufacturing method will be described.

[1] Formation of first-stage methacrylate polymer First, a method for producing the first-stage methacrylate polymer will be described below.
The methacrylate polymer can be obtained by emulsion polymerization of the raw material monomer in the presence of a radical polymerization initiator, preferably further an emulsifier (first-stage polymerization).
The proportion of methyl methacrylate in 100 parts by mass of the raw material monomer of the methacrylate polymer is preferably 50 parts by mass or more, more preferably 50 to 80 parts by mass.
Examples of the raw material monomer that can be used other than methyl methacrylate include those exemplified as the “radical polymerizable monomer” used in the preparation of the dispersion liquid (A) described later.
Examples of the emulsifier and the radical polymerization initiator include those described later.
The reaction conditions are, for example, about 40 to 98 ° C. and about 5 minutes to 3 hours.
Through such a reaction, a latex containing a plurality of particles made of a methacrylate polymer is obtained. The “50% number average particle diameter” of the particles made of the methacrylate polymer (the measurement method is the method described in the Examples. Hereinafter, it may be simply referred to as “average particle diameter”), for example, about 10 to 500 nm. It is suitable to control to.

[2] Formation of second-stage rubber-like copolymer A “methacrylate-based polymer” is obtained by this first-stage polymerization, and then a “rubber-like copolymer” is obtained by second-stage polymerization. Form.
The glass transition temperature of the rubbery copolymer is preferably less than 25 ° C. in order to sufficiently exhibit impact resistance.
In the “multi-stage copolymer”, first, after forming particles made of the methacrylate polymer, a latex containing particles forming a “rubber-like copolymer” having a crosslinked structure is produced (second stage polymer). Preferably, a monomer copolymerizable with the “rubber-like copolymer” of the particles in the latex is further added, and the particles in the latex and the copolymerizable monomer are added. It is preferable to produce by graft polymerization (third stage polymerization). The impact resistance can be improved by graft polymerization.

The “rubber-like copolymer” can be formed from a rubber component such as a commonly used diene rubber, acrylic rubber, silicone rubber or silicone / acrylic composite rubber, and has weather resistance and transparency. From the viewpoint, acrylic rubber is preferable.
As the acrylic rubber, it is preferable to use a copolymerizable monomer containing a “polyfunctional polymerizable compound” having an acrylic ester as a main component and having two or more ethylenically unsaturated bonds in the molecule. An acrylic acid ester polymer obtained by copolymerization may be mentioned.
As the acrylate ester of the main component, an acrylate ester having 4 to 10 carbon atoms in the alkyl group constituting the ester portion such as n-butyl acrylate and 2-ethylhexyl acrylate is preferable. These may be used alone or in combination of two or more. By using two or more of these, a polyalkyl (meth) acrylate composite rubber having two or more glass transition temperatures can be obtained.
“(Meth) acrylate” indicates one or both of methacrylate and acrylate.
In the present specification, unless otherwise specified, an “alkyl group” having 3 or more carbon atoms may be either linear or branched.
The blending amount of the main component acrylic acid ester mainly constituting the rubber part is preferably 40 to 97 mass in 100 mass parts of the raw material monomer (raw material monomer constituting the “rubber-like copolymer” before graft polymerization). Part, more preferably 50 to 90 parts by weight, from the viewpoint of developing rubbery properties.

The “polyfunctional polymerizable compound” is used for obtaining a rubbery characteristic by developing a crosslinked structure. Examples of the “polyfunctional polymerizable compound” include vinyl cyanide compounds such as (meth) acrylonitrile; ethylene glycol di (meth) acrylate, allyl (meth) acrylate, divinylbenzene, 1,3-butylene (meth) acrylate, and the like. . Of these, allyl (meth) acrylate and 1,3-butylene (meth) acrylate are preferred.
“(Meth) acrylonitrile” refers to one or both of methacrylonitrile and acrylonitrile.
The “polyfunctional polymerizable compound” can be used alone or in combination.
The “polyfunctional polymerizable compound” is preferably used in the range of 0.01 to 3 parts by mass, more preferably 0.5 to 2 parts by mass in 100 parts by mass of the raw material monomer of the “rubbery copolymer”. . By setting it as 0.01 mass part or more, a favorable rubber-like characteristic can be expressed, and by setting it as 3 mass parts or less, it becomes easy to form sea island-like shade, and impact resistance improves.

Examples of copolymerizable monomers other than “polyfunctional polymerizable compounds” include styrene monomers such as styrene and α-methylstyrene; methacrylic acid esters such as methyl methacrylate and ethyl methacrylate; methyl acrylate and ethyl acrylate Acrylic acid ester having 1 to 3 carbon atoms in the alkyl group.
These can be used alone or in combination.

In the acrylic rubber, from the viewpoint of transparency of the methacrylic resin molded product, it is preferable to adjust the refractive index to ensure good transparency.
For example, as shown in FIG. 5, when the methacrylic resin constituting the methacrylic resin portion 40 and the island portion (unstained portion) 43b is composed of only methyl methacrylate, a rubbery copolymer of a multistage polymerization copolymer is used. In 100 parts by mass of the raw material monomer of “rubbery copolymer”, 0.01 to 3 parts by mass of “polyfunctional polymerizable compound”, 75 to 85 parts by mass of n-butyl acrylate, and 12 to 24.99 of styrene. When formed by copolymerization at a ratio of parts by mass, the total light transmittance in the visible light wavelength region is 90% or more and a haze value of 10 or less when the methacrylic resin molded product is formed into a plate shape of about 3 mm. Good transparency can be obtained. The total light transmittance and haze can be measured by the methods described in the examples.

In the second stage polymerization, for example, a polymerization method for polymerizing acrylic rubber is not particularly limited, and examples thereof include a normal emulsion polymerization method and a soap-free emulsion polymerization method. If necessary, a forced emulsion polymerization method can be used. The soap-free emulsion polymerization method is preferable because it is easy to design particles having a large particle size.
Examples of radical polymerization initiators used in the polymerization reaction include water-soluble persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate; -Redox initiators containing organic peracid peroxides such as butyl hydroperoxide and t-hexyl peroxypivalate as one component; or a combination of the organic peroxide and one or more reducing agents can do.
These can be used alone or in combination.

The emulsifier used in the polymerization reaction is not particularly limited. For example, alkali metal salts of higher fatty acids such as disproportionated rosin acid, oleic acid, stearic acid; dodecylbenzenesulfonic acid, sodium dialkylsulfosuccinate 1 or more types of sulfonic acid alkali metal salts, such as these, can be added.
These can be used alone or in combination.

In forming the “rubber-like copolymer” in this way, the water-soluble persulfate alone or a trace amount of emulsifier is used in combination in the latex obtained after the reaction to form the “rubber-like copolymer”. The average particle diameter of the particles can be designed in the range of 50 nm to 800 nm.
The reaction for forming the rubbery copolymer is performed under conditions of, for example, 40 to 98 ° C. and about 5 minutes to 2 hours.

Next, a copolymerizable monomer is added to the obtained latex, and graft polymerization is performed thereby (third stage polymerization) to complete a “multistage polymerization copolymer”.
The “copolymerizable monomer” used in the graft polymerization can be copolymerized with a “rubbery copolymer” and preferably does not contain an epoxy group, a glycidyl group, an isobornyl group, an allyl group, or a hydroxyl group. Those are preferred.
By using a monomer that does not contain an epoxy group, a glycidyl group, an isobornyl group, an allyl group, or a hydroxyl group, the dispersibility of the multistage polymerization copolymer is improved.
Examples of the “copolymerizable monomer” include, for example, methacrylic acid alkyl esters such as methyl methacrylate and ethyl methacrylate; acrylic acid alkyl esters such as ethyl acrylate and n-butyl acrylate; styrene, α-methyl styrene, and various halogens. An aromatic vinyl such as an alkyl-substituted styrene substituted or substituted with an alkyl group having 1 to 4 carbon atoms; an unsaturated nitrile such as acrylonitrile or methacrylonitrile;
These can be used alone or in combination.
The “copolymerizable monomer” is preferably used in an amount of 70 to 10 parts by mass in 100 parts by mass of the multistage polymerization copolymer. Impact resistance can be improved as it is 70 mass parts or less. When it is 10 parts by mass or more, the fusion between the primary particles is weak, and the dispersion time of the multistage polymerization copolymer can be shortened.
In the graft polymerization, a chain transfer agent such as n-octyl mercaptan or n-dodecyl mercaptan is preferably used. And it is preferable to add the mixture which mixed the said monomer which can be copolymerized with the chain transfer agent to latex. In the graft polymerization, in consideration of the balance of the dispersibility and impact strength of the multistage polymerization copolymer, a one-stage or two-stage or more multistage polymerization reaction can be performed as necessary.

  The conditions for the graft polymerization are, for example, 40 to 98 ° C. and about 0.5 to 8 hours.

In this way, a latex containing a multistage polymerization copolymer is obtained by providing a methacrylate polymer by the first stage polymerization and forming a rubbery copolymer by the subsequent second stage polymerization. The multistage copolymer is recovered from the latex and used in the next step.
Further, the average particle diameter can be controlled by enlarging the produced multistage polymerization copolymer with an acid or a salt.
The smaller the average particle size of the multistage polymerization copolymer, the more likely it is to obtain a methacrylic resin molded article with better transparency. There exists a tendency for the methacrylic resin molded product excellent in property to be obtained.
The average particle size of the multistage polymerization copolymer is more preferably 200 nm or more, and particularly in the range of 200 to 500 nm. Since the fusion between the primary particles is weak by being more than the lower limit value, the dispersibility of the multistage polymerization copolymer is further improved in the production process of the methacrylic resin molded product, and the multistage polymerization copolymer is dispersed. The time is further shortened and productivity is improved. Moreover, since the viscosity characteristic is also appropriate, productivity can be further improved. Furthermore, as will be described later, the operation of recovering the multistage polymerization copolymer from the latex, preferably by spray drying, becomes easy. Transparency improves further by being below an upper limit. For applications that do not require much transparency, the average particle size of the multistage copolymer may be about 800 nm.
Examples of a method for recovering the multistage polymerization copolymer in the latex include spray drying, acid coagulation, salt coagulation, and the like, and a method by spray drying in which the primary particles are less fused is preferable. Thereby, the dispersibility of a multistage polymerization copolymer can be improved.

Spray drying is a method in which latex is sprayed in the form of fine droplets, and the sprayed product is dried by applying hot air in a dryer.
As a device for spraying latex in the form of fine droplets, any type of device such as a rotating disk type, a pressure nozzle type, a two-fluid nozzle type, a pressurized two-fluid nozzle type, etc. may be used.
The capacity of the dryer can be used from a small scale used in a laboratory to a large scale used industrially. Further, in the dryer, the position of the inlet part which is the supply part of the heating gas for drying and the outlet part which is the outlet for the heating gas for drying and the dry powder are also the same as the spray drying apparatus which is usually used. Good. The temperature of hot air introduced into the apparatus (hot air inlet temperature), that is, the maximum temperature of hot air contacting the multistage polymerization copolymer is preferably 200 ° C. or less, particularly preferably in the range of 120 to 180 ° C.

In addition, when spray-drying, it is possible to dry a latex containing one type of multistage polymerization copolymer, or to mix latexes containing different types of multistage polymerization copolymers obtained by a plurality of reactions. It can also be dried at once.
During spray drying, in order to improve powder characteristics such as blocking and bulk specific gravity, inorganic fillers such as silica, talc and calcium carbonate, polyacrylate, polyvinyl alcohol, polyacrylamide, etc. may be added to the latex. Good.
In addition, it is possible to spray dry by adding an appropriate antioxidant or additive to the latex.

  In addition, when forming each layer of a multistage polymerization copolymer, it can also be made to react by adding an appropriate antioxidant and additive beforehand as needed.

<Manufacture of methacrylic resin molded products>
Next, a methacrylic resin molded product is produced using this multistage polymerization copolymer.
The amount of the multistage polymerization copolymer used is preferably 4 to 30 parts by mass, particularly 5 to 15 parts by mass in 100 parts by mass of the methacrylic resin molded product. By being 4 parts by mass or more, for example, three times or more of impact resistance is exhibited with respect to those not containing the multistage polymerization copolymer, and by setting it to 30 parts by mass or less, the viscosity becomes appropriate and will be described later. Operability at the time of pouring into the mold is improved.

In the production of a methacrylic resin molded product, a mixed solution containing a “multi-stage polymerization copolymer” and a “methyl methacrylate-based raw material” is prepared and cured.
This mixed solution can be prepared by mixing a multistage polymerization copolymer and a methyl methacrylate-based raw material at one time, but preferably a methyl methacrylate-based containing a radical polymerizable monomer mainly composed of methyl methacrylate. A step of preparing the dispersion liquid (A) by dispersing the multistage polymerization copolymer in the raw material (B-1);
A methyl methacrylate raw material (B-) containing the dispersion (A) and a polymer of a radical polymerizable monomer mainly containing methyl methacrylate and / or a radical polymerizable monomer mainly containing methyl methacrylate. It is preferable to manufacture through the process of mixing 2).
At the time of production of the methacrylic resin molded product, the methyl methacrylate raw material (B-1) and the methyl methacrylate raw material (B-2) are mixed with the methacrylic resin portion 40 and the island portion (undyed portion) as shown in FIG. 43b.
By preparing the dispersion liquid (A) in this way in advance, the methacrylic resin is likely to enter the rubber-like copolymer, sea-island shades are easily formed, and the impact resistance is improved.

The polymerization method of the mixed solution may be any of a bulk polymerization method, a suspension polymerization method, and a solution polymerization method, but a bulk polymerization method is preferable.
Examples of a method for obtaining a methacrylic resin molded product include a method obtained by extrusion by a T-die extrusion method, and a method in which the mixed solution is poured into a mold and cast polymerization is preferable. When the casting polymerization method is used, sea-island shades composed of a rubbery copolymer and a methacrylic resin are easily formed in the finished methacrylic resin molded article, and the impact resistance is improved. In particular, excellent impact resistance can be obtained even if the addition amount of the multistage polymerization copolymer is small.

Hereinafter, the above-described preferred method will be specifically described according to a procedure.
[1] Preparation of Dispersion (A) First, the multistage polymerization copolymer is dispersed in a methyl methacrylate raw material (B-1) containing a radical polymerizable monomer having methyl methacrylate as a main component. A step of preparing (A) is performed.
The “radically polymerizable monomer” is mainly composed of methyl methacrylate as described above. Here, the main component preferably means that 50 parts by mass or more of methyl methacrylate is contained in a total amount of 100 parts by mass, and may be methyl methacrylate alone or may be copolymerized with methyl methacrylate and methyl methacrylate. It may be a mixture of “monomers”.

  Examples of “other monomers” include methacrylic acid esters such as ethyl methacrylate, isopropyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, phenyl methacrylate, and benzyl methacrylate; methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate Acrylic acid esters such as; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid and itaconic acid; acid anhydrides such as maleic anhydride and itaconic anhydride; maleimide derivatives such as N-phenylmaleimide and N-cyclohexylmaleimide Hydroxy group-containing monomers such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate; vinyl acetate, vinyl benzoate Vinyl esters such as vinyl chloride, vinylidene chloride and derivatives thereof; nitrogen-containing monomers such as methacrylamide and acrylonitrile; epoxy group-containing monomers such as glycidyl acrylate and glycidyl methacrylate; styrene, α-methylstyrene, etc. An aromatic compound having an ethylenically unsaturated bond in the molecule can be used.

Depending on the purpose, together with the above monomers, ethylene glycol di (meth) acrylate, 1,2-propylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,6- Alkanediol di (meth) acrylate such as hexanediol di (meth) acrylate; diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, triethylene glycol (meth) acrylate, tetraethylene glycol dimethacrylate, polyethylene glycol di Polyfunctional alkylene compound having two or more ethylenically unsaturated bonds in the molecule, such as polyoxyalkylene glycol di (meth) acrylate such as (meth) acrylate; divinylbenzene; allyl (meth) acrylate It can also be used.
These may be used alone or in combination of two or more.

  In addition to the “radical polymerizable monomer”, a polymer of “radical polymerizable monomer” can be blended in the methyl methacrylate-based raw material (B-1). This polymer preferably has a mass average molecular weight of 300,000 or less (substantially 50,000 or more) from the viewpoint of operability. In addition, the blending amount of this polymer is preferably 10 parts by mass or less in terms of viscosity in the total of 100 parts by mass of the “radical polymerizable monomer” and the polymer in terms of viscosity.

The dispersion (A) can be prepared by mixing the multistage polymerization copolymer and the methyl methacrylate-based raw material (B-1).
In this dispersion (A), the blending amount of the multistage polymerization copolymer is preferably 5 to 60 parts by mass in 100 parts by mass of the dispersion (A) from the viewpoint of improving impact resistance.

[2] Step of mixing the dispersion (A) and the methyl methacrylate-based raw material (B-2) // Methyl methacrylate-based raw material (B-2) containing a radical polymerizable monomer containing methyl methacrylate as a main component is mixed to prepare a mixed solution.

The methyl methacrylate-based raw material (B-2) is (I) “a polymer of a radical polymerizable monomer mainly composed of methyl methacrylate”,
(II) One or both of “radical polymerizable monomers mainly composed of methyl methacrylate” are included.

As the “radical polymerizable monomer” of (II), the same one as that used in the methyl methacrylate raw material (B-1) can be used.
(I) “A polymer of a radical polymerizable monomer having methyl methacrylate as a main component” is the same as that of the “radical polymerizable monomer” similar to that used in the methyl methacrylate raw material (B-1). It is a coalescence. Here, as in the case described above, the main component means that the total amount is preferably 50 parts by mass or more in 100 parts by mass.
However, from the viewpoint of viscosity, the polymer preferably has a mass average molecular weight of 300,000 or less (substantially 50,000 or more).

The method of mixing the dispersion (A) and the methyl methacrylate-based raw material (B-2) is a method in which the methyl methacrylate-based raw material (B-2) is directly added to and mixed with the container in which the dispersion (A) is prepared. A method in which the dispersion (A) is added to and mixed with the methyl methacrylate-based raw material (B-2).
In the latter case, for example, methyl methacrylate-based raw material (B-2) is fed through a pipe, and in the middle of that, the dispersion (A) is fed from another pipe connected to the pipe, and these are sent to the pipe. For example, there is a method of mixing in a mixing device provided in the middle and pouring the obtained mixed solution into a mold to be described later. When an apparatus using such a pipe is used, the tank capacity of a mixing apparatus or the like can be designed to be small.
Further, when the methyl methacrylate-based raw material (B-2) is composed of a plurality of components, the mixture may be mixed with the dispersion (A) after mixing them, or the plurality of components may be sequentially dispersed. You may mix in (A).

  The methyl methacrylate-based material (B-2) is preferably used at a ratio of 20 to 80 parts by mass in 100 parts by mass of the mixed liquid of the dispersion (A) and the methyl methacrylate-based material (B-2).

[3] Casting polymerization of mixed solution Next, casting polymerization is performed by pouring the mixed solution of the dispersion (A) and the methyl methacrylate-based raw material (B-2) into a mold and advancing the polymerization reaction.
In carrying out the polymerization reaction, it is preferable to add a radical polymerization initiator such as an azo compound or an organic peroxide to the mixed solution.
Specific examples of the azo compound include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethyl-4). -Methoxyvaleronitrile) and the like.
Specific examples of the organic peroxide include t-hexyl peroxybivalate, benzoyl peroxide, lauroyl peroxide, and the like. A redox polymerization initiator, for example, a combination of an organic peroxide and an amine can also be used.

In each of the steps [1] to [3], one or two or more of the dispersion (A), the methyl methacrylate-based raw material (B-2), or a mixture thereof, as necessary, It is preferable to add a chain transfer agent such as n-dodecyl mercaptan. In addition, a mold release agent, a colorant, an ultraviolet absorber, a heat stabilizer, an antistatic agent, a filler, and the like can be added. The order of addition and the timing of addition are not particularly limited.
The viscosity of the liquid mixture to be poured into the mold (at 20 ° C., measured at a rotation speed of a B-type viscometer at 6 rpm, the same applies hereinafter) is preferably 100 to 20000 mPa · s, particularly preferably 200 to 15000 mPa · s. . By being above the lower limit value, the mixed liquid is difficult to leak from the periphery of the gasket constituting the mold described later, and by being below the upper limit value, the pouring into the mold is good. The viscosity of the mixed liquid is increased by blending the polymer of the radical polymerizable monomer in the methyl methacrylate raw material, increasing the polymerization degree (lower), increasing the blending amount (reducing), etc. ( Low).

As the mold, for example, it is preferable to use a mold in which two flat plates are opposed to each other with a gap therebetween and a peripheral portion thereof is sealed with a gasket made of plastic or the like. In this mold, a space surrounded by a flat plate and a gasket is formed. As the flat plate, a glass plate, a metal plate made of stainless steel, or the like is used.
The casting mold is provided with an inlet for injecting the mixed liquid into the space. And the said liquid mixture is inject | poured into the said space part, and casting polymerization is performed. A method using such a mold is called a “cell cast method”.
Further, the “continuous casting method” using a molding apparatus using a pair of endless belts is preferable because of high productivity.
In this molding apparatus, the pair of endless belts travels in the same direction and at the same speed. As the endless belt, a stainless steel endless belt whose surface is mirror-polished is preferable. The pair of endless belts are arranged so as to face each other with a gap therebetween, and the vicinity of the end in the width direction (near both ends) is sealed with a gasket, so that the endless belt and the gasket An enclosed space is formed. And this space part functions as a casting_mold | template.
Then, from the upstream side in the running direction of the endless belt, the mixed liquid is continuously injected into the space, heated to be cured, and the cured product is peeled off from the endless belt. Obtainable.

The polymerization temperature varies depending on the type of radical polymerization initiator used, but is generally 10 to 150 ° C.
The shape of the methacrylic resin molded product is not particularly limited, and for example, a flat plate shape is preferable. The thickness is preferably in the range of 0.2 to 150 mm, for example.

In the methacrylic resin molded product, the gel content of the entire methacrylic resin molded product is preferably 1.3 times or more, more preferably 1.5 times or more, particularly preferably with respect to the gel content of the multistage polymerization copolymer. Is 1.7 times or more. The larger the difference, the better. Therefore, there is no technical significance for defining the upper limit value, but the difference is substantially 5 times or less.
When the ratio of the gel content is 1.3 times or more, impact resistance is further improved.
Here, the ratio of the gel content of the methacrylic resin molded product to the gel content and the gel content of the multistage polymerization copolymer can be measured by the method shown in the Examples.
The ratio of the gel content of the methacrylic resin molded product to the gel content of the multistage polymerization copolymer is such that the more methyl methacrylate resin [that is, the island portion (unstained portion)] that enters the “rubber-like copolymer”. There is a tendency to grow. Therefore, impact resistance improves as the ratio of the gel component increases.
The gel content of the multistage polymerization copolymer can be adjusted by the addition amount of the polyfunctional polymerizable compound used in the rubbery copolymer and the addition amount of the chain transfer agent during graft polymerization. The gel content tends to increase (decrease) by increasing (decreasing) the addition amount, and the gel tends to decrease (enlarge) by increasing (decreasing) the amount of chain transfer agent added during graft polymerization.
As described above, the ratio of the gel content of the methacrylic resin molded product and the gel content can be reduced by reducing the degree of crosslinking of the “rubbery copolymer” or by adopting a production method in which the dispersion (A) is prepared in advance. Can be bigger.

[Methacrylic resin laminate]
The methacrylic resin laminate of the present invention is characterized by having a hard coat film and a layer comprising the methacrylic resin molded product of the present invention.
By providing a hard coat film, scratch resistance can be improved.
Hereinafter, the methacrylic resin laminate will be described in detail together with the manufacturing method.

For example, on the surface of a methacrylic resin molded article, a curable composition to be a hard coat film is applied to form a coating film, which is cured by irradiation with an activation energy ray such as ultraviolet rays or heating. And a methacrylic resin laminate provided with a hard coat film.
In addition, a coating film made of a curable composition is formed in a mold, and this is cured by irradiating an activation energy ray such as ultraviolet rays or heating to form a hard coat film. A methacrylic resin laminate provided with a hard coat film is obtained by injecting the above-mentioned mixed liquid of the raw material of the resin-based resin molded product and performing casting polymerization.

The hard coat coating can be provided on one side or both sides of a layer made of a methacrylic resin molded product. When a hard coat film is provided on one side, it is preferable to use the hard coat film on the side where impact or friction is applied during use.
The thickness of the hard coat film is preferably in the range of 10 to 30 μm. When it is 10 μm or more, the scratch resistance is improved, and when it is 30 μm or less, cracking at the time of cutting hardly occurs and the workability is good.
In addition, in the methacrylic resin laminated product, an antireflection film or an antistatic layer is formed on the hard coat film or between the hard coat film and the layer made of the methacrylic resin molded product as necessary. You can also.

The hard coat film is preferably a cross-linking obtained by adding “photopolymerization initiator (a-2)” to “polymerizable compound (a-1) having at least two (meth) acryloyloxy groups in the molecule”. It can be formed by irradiating an active energy ray such as ultraviolet rays to the curable curable composition. Or it can manufacture by heating the coating film which apply | coated the silicone type and melamine type crosslinkable hardening liquid (curable composition).
Then, ultraviolet rays are added to a curable composition obtained by adding “photopolymerization initiator (a-2)” to “polymerizable compound (a-1) having at least two (meth) acryloyloxy groups in the molecule”. It is preferable to form by a method of irradiating activation energy rays such as from the viewpoint of curing speed.
Here, “(meth) acryloyloxy group” represents one or both of a methacryloyloxy group and an acryloyloxy group.

The polymerizable compound (a-1) is preferably a compound in which two or more (meth) acryloyloxy groups are combined with a hydrocarbon or a derivative thereof.
As a hydrocarbon, a C1-C20 thing is preferable. In addition, as derivatives thereof, in the hydrocarbon molecule, ether bond (—O—), thioether bond (—S—), ester bond (—COO—), amide bond (—CONH—), urethane bond (—OCONH) -) Etc. can be mentioned.
As main examples of the polymerizable compound (a-1), esterified products obtained by esterifying 1 mol of polyhydric alcohol and 2 mol or more of (meth) acrylic acid or derivatives thereof; Examples thereof include linear esterified products obtained by esterifying a monohydric alcohol, a polyvalent carboxylic acid or an anhydride thereof, and (meth) acrylic acid or a derivative thereof.
(Meth) acrylic acid represents one or both of acrylic acid and methacrylic acid.
Examples of the aforementioned (meth) acrylic acid derivatives include (meth) acrylates having 1 to 20 carbon atoms in the alkyl group constituting the ester moiety.

As the former, di (meth) acrylate of polyethylene glycol such as diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate; 1,4-butanediol di (meth) acrylate 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, pentaglycerol tri (meth) acrylate , Pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, glycerin tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipenta Rithritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tripentaerythritol tetra (meth) acrylate, tripentaerythritol penta (meth) acrylate, tripentaerythritol hexa (meta) ) Acrylate, tripentaerythritol hepta (meth) acrylate, and the like.
Of these, 1,6-hexanediol di (meth) acrylate and pentaerythritol tri (meth) acrylate are preferable.

  In the latter, preferred combinations of polyhydric alcohol and polyhydric carboxylic acid or anhydride thereof and (meth) acrylic acid include malonic acid / trimethylolethane / (meth) acrylic acid, malonic acid / trimethylolpropane / ( (Meth) acrylic acid, malonic acid / glycerin / (meth) acrylic acid, malonic acid / pentaerythritol / (meth) acrylic acid, succinic acid / trimethylolethane / (meth) acrylic acid, succinic acid / trimethylolpropane / (meta ) Acrylic acid, succinic acid / glycerin / (meth) acrylic acid, succinic acid / pentaerythritol / (meth) acrylic acid, adipic acid / trimethylolethane / (meth) acrylic acid, adipic acid / trimethylolpropane / (meth) Acrylic acid, adipic acid / glycerin / (meth) acrylic acid, a Pinic acid / pentaerythritol / (meth) acrylic acid, glutaric acid / trimethylolethane / (meth) acrylic acid, glutaric acid / trimethylolpropane / (meth) acrylic acid, glutaric acid / glycerin / (meth) acrylic acid, glutar Acid / pentaerythritol / (meth) acrylic acid, sebacic acid / trimethylolethane / (meth) acrylic acid, sebacic acid / trimethylolpropane / (meth) acrylic acid, sebacic acid / glycerin / (meth) acrylic acid, sebacic acid / Pentaerythritol / (meth) acrylic acid, fumaric acid / trimethylolethane / (meth) acrylic acid, fumaric acid / trimethylolpropane / (meth) acrylic acid, fumaric acid / glycerin / (meth) acrylic acid, fumaric acid / Pentaerythritol / (meth) acrylic acid Itaconic acid / trimethylolethane / (meth) acrylic acid, itaconic acid / trimethylolpropane / (meth) acrylic acid, itaconic acid / glycerin / (meth) acrylic acid, itaconic acid / pentaerythritol / (meth) acrylic acid, anhydrous Maleic acid / trimethylolethane / (meth) acrylic acid, maleic anhydride / trimethylolpropane / (meth) acrylic acid, maleic anhydride / glycerin / (meth) acrylic acid, maleic anhydride / pentaerythritol / (meth) acrylic An acid etc. can be mentioned.

Other examples of the polymerizable compound (a-1) include trimethylolpropane toluylene diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, xylene diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), isophorone diisocyanate, Polyisocyanates obtained by trimerization such as trimethylhexamethylene diisocyanate and acrylic monomers having active hydrogen, such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-methoxypropyl (Meth) acrylate, N-methylol (meth) acrylamide, N-hydroxy (meth) acrylamide, 1,2,3-propanetrio Urethane (meth) acrylate obtained by reacting at least 3 moles per mole of 1,3-di (meth) acrylate, 3-acryloyloxy-2-hydroxypropyl (meth) acrylate, etc .; Tris (2 -Poly [(meth) acryloyloxyethylene] isocyanurate such as di (meth) acrylate and tri (meth) acrylate of hydroxyethyl) isocyanuric acid; known epoxy polyacrylate; known urethane polyacrylate.
Note that “(meth) acryloyl” represents one or both of “acryloyl” and “methacryloyl”.
Among these, a urethane compound obtained by reacting 3 mol of 3-acryloyloxy-2-hydroxypropyl methacrylate with 1 mol of triisocyanate formed by trimerizing hexamethylene diisocyanate is preferable.

  The polymerizable compound (a-1) can be used alone or in combination of two or more as required.

Specific examples of the photopolymerization initiator (a-2) include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, acetoin, butyroin, toluoin, benzophenone, p-methoxybenzophenone, 2,2- Diethoxyacetophenone, α, α-dimethoxy-α-phenylacetophenone, methylphenylglyoxylate, ethylphenylglyoxylate, 4,4′-bis (dimethylamino) benzophenone, 2-hydroxy-2-methyl-1-phenyl Carbonyl compounds such as propan-1-one; sulfur compounds such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide; 2,4,6-trimethylbenzoyldiphenylphosphine oxide And benzoyldiethoxyphosphine oxide.
Of these, benzoin ethyl ether and 2-hydroxy-2-methyl-1-phenyl-propan-1-one are preferable.

  The preferable addition amount of a photoinitiator (a-2) is 0.1 mass part-10 mass parts with respect to 100 mass parts of polymeric compounds (a-1). When it is 0.1 parts by mass or more, curability is improved, and when it is 10 parts by mass or less, the hard coat film is difficult to be colored, which is preferable. A photoinitiator (a-2) can be used 1 type or in mixture of 2 or more types.

  Various additives may be added to the curable composition containing the polymerizable compound (a-1) and the photopolymerization initiator (a-2) depending on the purpose. As the additive, conventionally known additives can be appropriately used, and examples thereof include surfactants, leveling agents, dyes, pigments, antioxidants, ultraviolet absorbers, stabilizers, flame retardants, and plasticizers. The addition amount of the additive can be appropriately selected within a range in which the good physical properties of the hard coat film can be obtained. For example, with respect to a total of 100 parts by mass of the polymerizable compound (a-1) and the photopolymerization initiator (a-2). It is preferable that it is 10 mass parts or less.

  Examples of the method for applying the curable composition on the methacrylic resin molded product include an air knife coating method, a film cover method, a casting method, a roller coating method, a bar coating method, a spray coating method, and a dipping method. The air knife method and the film cover method are preferable because a uniform coating film can be easily formed.

FIG. 1 is an explanatory diagram of the air knife method. When a hard coat film is formed on a methacrylic resin molded article using the air knife method, first, as shown in FIG. 1, the flat methacrylic resin molded article 1 is run at a constant speed in the direction of the arrow. Then, a curable composition is supplied from the spray nozzle pipe 2 and air is blown onto the entire coating film made of the curable composition at a constant flow rate by the air nozzle 3 to form a coating film having a uniform film thickness. And a hard coat film is obtained by irradiating this coating film with activation energy rays such as ultraviolet rays or heating this coating film.
When using the film cover method, a resin film is first prepared. Then, a curable composition is applied to one side of a flat methacrylic resin molded article to form a coating film, and a laminated body is formed by covering the coating film with a resin film. A uniform coating film made of the curable composition is formed. Then, activation energy rays such as ultraviolet rays are irradiated through the resin film to cure the coating film to obtain a hard coat film.
The resin film is not particularly limited as long as it is insoluble in the curable composition and can be peeled off from the cured hard coat film, and a PET (polyethylene terephthalate) film is preferable from the viewpoints of cost and availability. .

In addition, when applying the casting polymerization method, for example, a step of forming a hard coat film in a mold, and a mixed liquid of a multistage polymerization copolymer and a methyl methacrylate-based material is poured into the mold on which the hard coat film is formed, It can be manufactured by a “cell cast method” which is cured by a casting polymerization method and undergoes a step of forming a layer made of a methacrylic resin molded product.
In this method, for example, a template having a structure as shown in FIG. 2 is used.
Reference numeral 5 in the figure denotes a mold. The mold 5 includes a flat plate 5a having a hard coat film 6 previously formed on one surface thereof, a flat plate 5b disposed so as to face the hard coat film 6 side, and these flat plates. It is comprised by the gasket 5c which seals the peripheral part of 5a, 5b. In this example, the flat plate 5a is disposed below and the flat plate 5b is disposed above.
The mold 5 is provided with an injection port (not shown) for injecting the mixed solution into the space 5 d on the hard coat film 6. As the flat plates 5a and 5b, glass plates, metal plates such as stainless steel, and the like are used. The gasket 5c is made of plastic or the like.
Examples of the method of providing the hard coat film 6 on the flat plate 5a include the same method as the method of providing the hard coat film on the methacrylic resin molded product described above.

Then, the mixed solution is injected into the space 5d on the hard coat film 6 of the mold 5 and cured to form a layer 7 made of a methacrylic resin molded product. Then, when the mold 5 is removed, the methacrylic resin is removed. A laminate is obtained.
In the casting polymerization method, since the hard coat film 6 is formed on the flat plate 5a having a smooth surface, the smoothness of the surface of the hard coat film 6 can be improved. Further, the adhesion between the methacrylic resin molded product 7 and the hard coat film 6 can be improved.
In this example, the method of providing the hard coat film 6 on the lower flat plate 5a has been described. However, the hard coat film 6 may be provided on the flat plate 5b, or both of these flat plates 5a and 5b. A hard coat film 6 may be provided thereon.

  Among these, casting polymerization is preferable, and one or both of the flat plates 5a and 5b of the mold 5 are used by using an air knife coating method and a film cover method, particularly from the viewpoint that a uniform coating film can be easily formed. A method in which the hard coat film 6 is first formed on the surface is preferable.

When the air knife coating method is used, in the apparatus shown in FIG. 1, the methacrylic resin molded product 1 can be replaced with the flat plate 5a, and the hard coat film 6 can be formed on the flat plate 5a.
By using the air knife method, the amount of the curable composition that is excessively applied and wasted can be reduced, which is advantageous in terms of cost reduction. Moreover, there are few restrictions on width (size), and a wide methacrylic resin laminate can be produced.
When the film cover method is applied, a hard coat film is formed on the flat plate 5a using a resin film such as a PET film in the same manner as the method for forming a hard coat film on the methacrylic resin molded product described above. 6 can be formed.

Also, a methacrylic resin laminate can be continuously produced by a casting polymerization method (continuous casting method) using the molding apparatus shown in FIGS. This method is excellent in productivity.
In this method, a pair of endless belts that run facing each other at a predetermined interval, and provided near both ends in the width direction of the pair of endless belts (near both side ends), run following this endless belt. Forming a hard coat film on one or both surfaces of the pair of endless belts in a molding apparatus having a space formed by the pair of endless belts and the pair of gaskets. And the step of continuously supplying the liquid mixture on the hard coat film located in the space of the molding apparatus and curing the mixture to form a layer made of a methacrylic resin molded product. -Based resin laminate can be obtained.

FIG. 3 is a sectional side view of the molding apparatus. FIG. 4 is a perspective view showing an endless belt disposed below.
Reference numerals 11A and 11B in the figure denote endless belts arranged to face each other with an interval in the vertical direction. Gaskets 12A and 12B are provided along the outer periphery of the endless belt 11B in the vicinity of both ends in the width direction of the lower endless belt 11B, and the gap between the endless belts 11A and 11B is sealed. The endless belts 11A and 11B and the space 13 surrounded by the gaskets 12A and 12B are formed.

In producing the methacrylic resin laminate, first, the endless belts 11A and 11B are cured at a constant speed and cured on the endless belt 11A from the curable composition supply nozzle 20 disposed above the endless belt 11A. The composition is supplied to form the coating film 21A. Then, this coating film 21A is irradiated with an activation energy ray such as ultraviolet rays using a light source 22 and cured to form a hard coat film 21B. The hard coat film 21B moves to the space 13 as the endless belt 11A travels.
Next, in the space 13, the mixed liquid is supplied between the hard coat film 21 </ b> B and the endless belt 11 </ b> B from the mixed liquid supply nozzle 30 provided on the upstream side in the traveling direction of the endless belts 11 </ b> A and 11 </ b> B, and heated. Then, the polymerization reaction is allowed to proceed, and the laminated product is peeled from the endless belts 11A and 11B on the downstream side in the running direction of the endless belts 11A and 11B, whereby a methacrylic resin laminated product 50 is obtained.
In this example, the curable composition is supplied from the endless belt 11A side, but the curable composition is provided upstream of the mixed solution supply nozzle 30 on the endless belt 11B in the same manner as the endless belt 11A. It is also possible to supply a product and form a hard coat film on the endless belt 11B. Also, a hard coat film can be formed on both the endless belts 11A and 11B.

Thus, in this invention, the methacrylic-type resin molded product which improved impact resistance, the methacrylic-type resin laminated product using the same, and these manufacturing methods can be provided.
Since the multistage polymerization copolymer used for the methacrylic resin molded product has a high impact resistance improving effect, the blending amount in the methacrylic resin molded product can be reduced. Therefore, the operation of dispersing the multistage polymerization copolymer can be performed efficiently in a short time, and productivity is improved.
Moreover, the methacrylic resin molded product of the present invention is excellent in transparency. It also has excellent heat resistance.
Moreover, in the methacrylic resin laminate of the present invention, since a hard coat film is provided on a layer made of a methacrylic resin molded article having good impact resistance, it has excellent impact resistance and scratch resistance.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto. In addition, in the said Example, unless otherwise indicated, "part" shall show a mass part and "%" shall show the mass%.

<1> Methacrylic resin molded product [Evaluation method]
The evaluation method according to the methacrylic resin molded product is as follows. The evaluation results are shown in Table 1.

(Latex particle size)
The obtained latex was diluted with distilled water, and a 50% number average particle diameter (“average particle diameter”) was measured using a laser diffraction scattering type particle size distribution analyzer [LA-910 (trade name) manufactured by Horiba, Ltd.]. (Abbreviated) was measured.

(For gel)
About 0.5 g of a sample and 50 cc of acetone were charged into a 200 ml eggplant type flask, set in a condenser of a reflux apparatus, and refluxed at 65 ° C. for 4 hours. The sample liquid after cooling was added to a centrifuge tube (cell) and separated by a centrifuge to collect only the precipitate.
The conditions of the centrifuge were as follows.
・ Rotation speed: 14000 rpm.
・ Time: 30 minutes.
-Atmospheric temperature: 4 ° C.
Warm the cell containing the precipitate in a water bath, dry acetone, and dry overnight in a vacuum dryer, then measure the mass of the cell where the residue remains inside, and based on the following formula: The “gel content” in the sample was determined.

a ₁ : Cell after centrifugal drying + mass of residue (g)
b ₁ : mass of the cell before centrifugation (g)
c ₁ : mass (g) of the sample before dissolution
d ₁ : mass (g) of an acetone-insoluble additive other than the multistage copolymer
The “mass of the acetone-insoluble additive other than the multistage copolymer” is a total of, for example, a diffusion agent such as an acetone-insoluble pigment, an inorganic filler, and a crosslinked polymer bead.

(Ratio of the gel content of the entire methacrylic resin molded product to the gel content of the multistage polymerization copolymer)
The gel content of the multistage polymer and the methacrylic resin molded product was calculated by the above method, and the increase in the gel content was calculated based on the following formula.

a _2: mass of the multistage polymerization copolymer methacrylic resin molded article 100 mass%%
b ₂ : Gel content (%) in 100% by mass of the multistage copolymer
c ₂ : Gel content (%) in 100% by mass of methacrylic resin molded product

(Surface impact strength: impact resistance)
In accordance with JIS K 7211, 50% fracture energy (J) was calculated by the Dupont falling weight test.

(Total light transmittance, haze value)
The total light transmittance (%) and haze (haze) (%) were measured with a Color Research Laboratory HR-100 haze meter (trade name) in an atmosphere of 23 ° C., respectively.

(viscosity)
At 20 ° C., the viscosity (mPa · s) of a B-type viscometer at 6 rpm was measured.

(Observation of sea-like shade)
A sample was cut out with a microtome so that the thickness of the methacrylic resin molded product was 80 nm, stained with ruthenium tetroxide, observed with a transmission electron microscope (TEM), and a photograph was taken at 140000 times.

[Production Example (Production of Multi-stage Polymerization Copolymer)]
(Production Example 1)
In a 5 L flask equipped with a stirrer and a condenser, 100 parts of pure water, sodium dialkylsulfosuccinate [manufactured by Kao Corporation, Perex OT-P (trade name)] 0.008 parts, 2.788 parts of methyl methacrylate, n- Nitrogen substitution was performed by adding 2 parts of butyl acrylate, 0.212 parts of styrene, 0.0188 parts of allyl methacrylate, and 0.15 parts of 1,3-butylene dimethacrylate. Warmed to. A solution obtained by dissolving 0.05 part of potassium persulfate in 5 parts of pure water was added all at once and held for 60 minutes to carry out the first stage polymerization.

Subsequently, a solution obtained by dissolving 0.1 part of potassium persulfate in 5 parts of pure water was added all at once to the obtained latex, and 40 parts of pure water, 47.44 parts of n-butyl acrylate, 10.06 parts of styrene, 1,44 parts of 1,3-butylene dimethacrylate, 0.575 part of allyl methacrylate, 0.36 part of sodium dialkylsulfosuccinate were mixed, and the nitrogen-substituted mixture was added dropwise over 280 minutes, and then held for 120 minutes. Second stage polymerization was performed.
Next, a nitrogen-substituted mixture of 35.625 parts of methyl methacrylate, 1.875 parts of methyl acrylate, and 0.113 parts of n-octyl mercaptan was added dropwise to the obtained latex over 120 minutes, and then held for 120 minutes. The third stage polymerization was performed to obtain a latex containing a multistage polymerization copolymer. When the average particle diameter of the “multistage copolymer” was measured using latex, it was 417 nm.

  Then, using a spray drier, fine particles of the obtained latex are sprayed by an atomizer with a rotational speed of 25000 rpm, and this is dried in a drier at a hot air inlet temperature of 150 ° C. A polymerization copolymer "was obtained. The gel content of the “multistage polymerization copolymer” was 76.2%.

(Production Example 2)
In the first-stage polymerization, the powdery "" A multistage copolymer was obtained.
The average particle diameter of the “multistage polymerization copolymer” was 230 nm, and the gel content of the obtained “multistage polymerization copolymer” was 76.5%.

(Production Example 3)
In the first stage polymerization, a powdery multi-stage polymerization copolymer was prepared in the same manner as in Production Example 1 except that the amount of sodium dialkylsulfosuccinate [manufactured by Kao, Perex OT-P (trade name)] was changed to 0 part. A polymer was obtained.
The average particle size of the “multistage polymerization copolymer” was 727 nm, and the gel content of the “multistage polymerization copolymer” was “74.7%.

(Production Example 4)
In the second stage polymerization, a powdery multistage polymerization copolymer was obtained in the same manner as in Production Example 1, except that the amount of allyl methacrylate was changed to 0.46 parts.
The average particle diameter of the “multistage polymerization copolymer” was 408 nm, and the gel content of the “multistage polymerization copolymer” was 73.2%.

(Production Example 5)
A powdery multistage copolymer was obtained in the same manner as in Production Example 1 except that the amount of allyl methacrylate was changed to 1.006 parts in the second stage polymerization.
The average particle diameter of the “multistage polymerization copolymer” was 414 nm, and the gel content of the “multistage polymerization copolymer” was 87.9%.

(Production Example 6)
In the second stage polymerization, production was carried out in the same manner as in Production Example 1 except that the amount of allyl methacrylate was changed to 2.875 parts to obtain a powdery multistage polymerization copolymer.
The average particle size of the “multistage polymerization copolymer” was 421 nm, and the gel content of the “multistage polymerization copolymer” was 92.8%.

[Examples and Comparative Examples]
(Example 1-1)
To a flask equipped with a stir bar, 43 parts of methyl methacrylate and 0.06 part of n-dodecyl mercaptan were added, and while stirring at 500 rpm, 7 parts of the multistage polymerization copolymer obtained in Production Example 1 was added and stirred for 30 minutes. A dispersion (A) was prepared.
Then, 0.32 part of t-hexylperoxypivalate and 50 parts of a partially polymerized methyl methacrylate were added and stirred for 5 minutes to obtain a mixed liquid having a viscosity of 600 mPa · s. The partially polymerized product of methyl methacrylate is a mixture of methyl methacrylate and methacrylate polymer, and 20% of the methacrylate is polymerized. The viscosity was 1000 mPa · s, the polymerization rate was 20%, and the “polymer” had a mass average molecular weight of 200,000.
Under reduced pressure, the dissolved air in the mixed solution was removed, and the mixture was poured into a mold having a space formed by a gasket and two tempered glasses having a thickness of 3 mm. This was heated in a warm water atmosphere at 78 ° C. for 45 minutes and then in an air atmosphere at 130 ° C. for 45 minutes to obtain a methacrylic resin molded product.

FIG. 5 is a photograph of the methacrylic resin molded product of Example 1-1 taken with a TEM.
As is clear from FIG. 5, sea-island shades having a sea part (stained part) 43a and an island part (unstained part) 43b could be confirmed.

(Example 1-2)
75.8 parts of methyl methacrylate and 0.06 part of n-dodecyl mercaptan are added to a flask equipped with a stir bar, and 14.2 parts of the multistage polymerization copolymer obtained in Production Example 1 is added while stirring at 500 rpm. The mixture was stirred for a minute to prepare a dispersion (A).
Next, 0.32 parts of t-hexylperoxypivalate and 10 parts of a methyl methacrylate partial polymer similar to those used in Example 1-1 were added and stirred for 5 minutes, and a mixed solution having a viscosity of 4100 mPa · s was added. Obtained.
Under reduced pressure, the dissolved air in the mixed solution was removed, and the mixture was poured into the same mold as that used in Example 1-1. This was heated in a warm water atmosphere at 76 ° C. for 50 minutes and then in an air atmosphere at 130 ° C. for 50 minutes to obtain a methacrylic resin molded product.

  Further, when the methacrylic resin molded product of Example 1-2 was photographed with a TEM, a photograph similar to FIG. 5 was obtained, and the unstained island portion (unstained) in the stained sea portion (stained portion) 43a. The presence of (stained portion) 43b could be clearly confirmed.

(Example 1-3)
In Example 1-1, a methacrylic resin molded product was obtained in the same manner as in Example 1-1, except that the amount of methyl methacrylate added was changed to 46 parts and the amount of the multistage polymerization copolymer added was changed to 4 parts. .
Further, when the methacrylic resin molded product of Example 1-3 was photographed with a TEM, a photograph similar to FIG. 5 was obtained, and an unstained island part (unstained) in the dyed sea part (stained part) 43a. The presence of (stained portion) 43b could be clearly confirmed.

(Example 1-4)
In Example 1-1, a methacrylic resin molded article was obtained in the same manner as in Example 1-1, except that the amount of methyl methacrylate added was changed to 48 parts and the amount of the multistage polymerization copolymer added was changed to 2 parts. .
Further, when the methacrylic resin molded product of Example 1-3 was photographed with a TEM, a photograph similar to FIG. 5 was obtained, and an unstained island part (unstained) in the dyed sea part (stained part) 43a. The presence of (stained portion) 43b could be clearly confirmed.

(Example 1-5)
In Example 1-1, a methacrylic resin molded article was obtained in the same manner as in Example 1-1 except that the multistage polymerization copolymer was changed to that produced in Production Example 2.
Further, when the methacrylic resin molded product of Example 1-5 was photographed with TEM, a photograph similar to FIG. 5 was obtained, and the unstained island part (unstained) in the dyed sea part (stained part) 43a. The presence of (stained portion) 43b could be clearly confirmed.

(Example 1-6)
In Example 1-1, a methacrylic resin molded article was obtained in the same manner as in Example 1-1 except that the multistage polymerization copolymer was changed to that produced in Production Example 3.
Further, when the methacrylic resin molded product of Example 1-6 was photographed with a TEM, a photograph similar to FIG. 5 was obtained, and the unstained island portion (unstained) in the stained sea portion (stained portion) 43a. The presence of (stained portion) 43b could be clearly confirmed.

(Example 1-7)
In Example 1-1, a methacrylic resin molded article was obtained in the same manner as in Example 1-1 except that the multistage polymerization copolymer was changed to that produced in Production Example 4.
Further, when the methacrylic resin molded product of Example 1-7 was photographed with a TEM, a photograph similar to FIG. 5 was obtained, and the unstained island portion (unstained) in the stained sea portion (stained portion) 43a. The presence of (stained portion) 43b could be clearly confirmed.

(Example 1-8)
In Example 1-1, a methacrylic resin molded article was obtained in the same manner as in Example 1-1 except that the multistage polymerization copolymer was changed to that produced in Production Example 5.
Further, when the methacrylic resin molded product of Example 1-8 was photographed with a TEM, a photograph similar to FIG. 5 was obtained, and the unstained island portion (unstained) in the stained sea portion (stained portion) 43a. The presence of (stained portion) 43b could be clearly confirmed.

(Example 1-9)
A flask with a stir bar was charged with 50 parts of a partially polymerized methyl methacrylate similar to that used in Example 1-1, 46 parts of methyl methacrylate, and 0.06 part of n-dodecyl mercaptan, and stirred at a rotational speed of 500 rpm. Then, 4 parts (3.05 parts of gel content) of the multistage polymerization copolymer obtained in Production Example 1 was added and stirred for 90 minutes to prepare a dispersion (A).
Next, 0.32 part of t-hexylperoxypivalate was added and stirred for 5 minutes to obtain a mixed solution having a viscosity of 550 mPa · s.
Under reduced pressure, the dissolved air in the mixed solution was removed, and then this was injected into the same mold as that used in Example 1-1. This was heated in a warm water atmosphere at 78 ° C. for 45 minutes and then in an air atmosphere at 130 ° C. for 45 minutes to obtain a methacrylic resin molded product.

  Moreover, when the methacrylic resin molded product of Example 1-9 was photographed with TEM, the photograph shown in FIG. 6 was obtained, and the unstained island part (unstained) in the dyed sea part (stained part) 43a. The presence of (part) 43b could be clearly confirmed.

(Example 1-10)
In Example 1-9, a methacrylic resin molded article was obtained in the same manner as in Example 1-9, except that the multistage polymerization copolymer was changed to that produced in Production Example 5.
When the methacrylic resin molded product of Example 1-9 was photographed with a TEM, a photograph similar to FIG. 6 was obtained, and the unstained island portion (unstained portion) in the stained sea portion (stained portion) 43a ) 43b could be clearly confirmed.

(Comparative Example 1-1)
In Example 1-1, a methacrylic resin molded article was obtained in the same manner as in Example 1-1 except that the multistage polymerization copolymer was changed to that produced in Production Example 6.
Moreover, when the methacrylic resin molded product of Comparative Example 1-1 was photographed with a TEM, the photograph shown in FIG. 7 was obtained, and in the second stage of the multi-stage copolymer, the dyed rubber-like copolymer was obtained. Unstained islands could not be confirmed in the sea.

(Comparative Example 1-2)
In Example 1-1, a methacrylic resin molded article was obtained in the same manner as in Example 1-1 except that the amount of methyl methacrylate added was 50 parts, and the multistage polymerization copolymer was not added.
In addition, since the multistage polymerization copolymer was not added, TEM observation was not performed.

  As is clear from the results shown in Table 1, good evaluation was obtained in Example 1-1 to Example 1-10 according to the present invention, and in particular, evaluation of 50% fracture energy was Comparative Example 1-1. It was confirmed that it was very good as compared with Comparative Example 1-2, and excellent impact resistance was obtained. The transparency was also good.

<2> Methacrylic resin laminate [Evaluation method]
The evaluation was carried out in the same manner as in the above method <1> for evaluating a methacrylic resin molded product, except for the evaluation of scratch resistance shown below. Regarding the gel content of the methacrylic resin molded product (impact resistant layer), only a methacrylic resin molded product (impact resistant layer) is produced without forming a hard coat film. Evaluation was performed in the same manner as the evaluation method. In “observation of sea-island-like shade”, a sample was cut out so that the thickness of the methacrylic resin molded product was 80 nm.
The evaluation results are shown in Table 2.

(Abrasion resistance)
Evaluation was made by the change in haze (scratch haze) before and after the scratch test shown below.
[Nihon Steel Wool Co., Ltd., Bonstar (trade name)] A circular pad with a diameter of 25.4 mm equipped with steel wool of # 000 was placed on the surface of the hard coat film of the sample, and this pad was loaded with a load of 9.8 N Below, a 20 mm distance was reciprocally scratched 100 times, and the difference in haze (scratch haze) before and after the scratch was determined based on the following formula and evaluated according to the following evaluation criteria. In addition, about the experiment example which did not provide a hard-coat film, the same test was done about the layer which consists of a methacrylic resin molded product.
The haze value was measured with a Color Research Laboratory HR-100 haze meter in an atmosphere at 23 ° C. in the same manner as in the above <1> methacrylic resin molded product.

Evaluation criteria ○: The value of the scratch haze is less than 0.2%.
X: The value of the scratch haze is 0.2% or more.

[Production example]
The production example is the same as <1> methacrylic resin molded product.

[Examples, experimental examples, comparative examples]
(Example 2-1)
(1) Preparation of liquid mixture To a flask with a stir bar, 43 parts of methyl methacrylate and 0.06 part of n-dodecyl mercaptan were added, and 7 parts of the multistage polymerization copolymer obtained in Production Example 1 was stirred while stirring at 500 rpm. In addition, the mixture was stirred for 30 minutes to prepare a dispersion (A).
Next, 0.32 parts of t-hexylperoxypivalate and 50 parts of a partially polymerized methyl methacrylate similar to that used in Example 1-1 were added, and the mixture was stirred for 5 minutes and mixed with a viscosity of 600 mPa · s. A liquid was obtained.

(2) Production of methacrylic resin laminate 3 As a polymerizable compound (a-1), 3 mol of 3-acryloyloxy-2-hydroxypropyl methacrylate is reacted with 1 mol of triisocyanate formed by trimerizing hexamethylene diisocyanate. 30 parts of urethane compound (trade name: NK ester U-6HA, manufactured by Shin-Nakamura Chemical Co., Ltd., hereinafter referred to as “U-6HA”), 1,6-hexanediol diacrylate (Osaka Organic) 60 parts by Chemical Industry Co., Ltd., hereinafter referred to as “C6DA”), 10 parts by pentaerythritol triacrylate (manufactured by Toagosei Co., Ltd., hereinafter referred to as “M305”), and a photopolymerization initiator ( As a-2), 1.5 parts of benzoin ethyl ether (BEE) was mixed and dissolved to prepare a curable composition.

Next, this curable composition was applied onto a mirror surface of a SUS304 plate having a mirror surface as a mold, and a PET (polyethylene terephthalate) film having a thickness of 12 μm was covered. A rubber roll having a JIS hardness of 40 ° was formed on the film. While squeezing out the excessive curable composition, it was pressure-bonded so as not to contain bubbles, so that the thickness of the coating film of the curable composition was 22 μm.
Next, with this PET film surface facing upward, a curable UV ray lamp having a power output of 40 W [FL40BL (trade name) manufactured by Toshiba Corporation] is passed 20 cm below at a speed of 0.3 m / min. The coating film of the composition was cured.

Then, the PET film was peeled off.
Next, the SUSU 304 plate is passed through the high-pressure mercury lamp with an output of 30 W / cm ² at a speed of 0.3 m / min with the coating film surface facing upward, and the coating film is irradiated with ultraviolet rays. After curing, a hard coat film having a film thickness of 20 μm was finally obtained.
The SUS304 plate on which the hard coat film is thus formed and the SUS304 plate on which the hard coat film is not formed are opposed to each other so that the hard coat film is on the inner side. A mold was prepared by sealing with a soft polyvinyl chloride gasket.

After the dissolved air was removed under reduced pressure from the mixed solution produced in (1) above, this mixed solution was poured into the mold, 45 minutes in a 78 ° C. water bath, and then 45% in a 130 ° C. air furnace. The polymerization reaction was carried out for minutes.
After cooling, the SUS304 plate was peeled from the mold to obtain a methacrylic resin laminate having a thickness of 3 mm having a hard coat film on one surface.

  Moreover, when the layer which consists of a methacrylic-resin molded product of the methacrylic-resin laminated product of Example 2-1 was image | photographed with TEM, the same photograph as FIG. 5 was obtained and the dye | stained sea part (dyed part) 43a The presence of an unstained island part (unstained part) 43b could be clearly confirmed.

(Example 2-2)
As the polymerizable compound (a-1), the same composition as in Example 2-1 was used. As the photopolymerization initiator (a-2), the following component (a-2-1) and (a- 2-2) A curable composition was prepared using two kinds of components.
Component (a-2-1): 2-hydroxy-2-methyl-1-phenyl-propan-1-one (trade name DAROCUR 1173, manufactured by Ciba Specialty Chemicals, Inc., hereinafter referred to as “DAROCUR 1173” 4 parts.
(A-2-2) Component: 2 parts of benzoin ethyl ether (BEE).

In the apparatus shown in FIG. 1, a SUS304 plate was used instead of the methacrylic resin molded product 1. In the following description of this embodiment, reference numeral 1 is indicated as “SUS board 1”. As the spray nozzle pipe 2, four circular spray nozzle pipes adjusted so as to have an average droplet diameter of 1 mm were arranged 150 mm away from the surface of the SUS plate 1 so as to form a line at 115 mm intervals in the width direction.
The air nozzle 3 is a slit type air nozzle of 600 mm in the width direction and has a slit clearance of 0.15 mm and an air flow rate of 1 m ³ / min. The mounting position of the air nozzle is 10 mm away from the surface of the sheet-like object 1. The air nozzle angle is arranged so as to be inclined 5 ° upstream from the downward direction with respect to the traveling direction of the SUS plate 1.
Then, the said curable composition was dripped on the upper surface of the SUS board 1 from the spray nozzle pipe 2, and the coating film with a thickness of 15 micrometers which consists of a curable composition was formed by spraying air from the air nozzle 3. FIG. The coating temperature was 25 ° C.
Next, the SUS plate 1 is placed at a speed of 2.5 m / min with a position 17 cm below the high pressure mercury lamp with an output of 120 W / cm ^{2 so} that the coating film side of the curable composition is disposed on the mercury lamp side. The coating film was cured to form a hard coat film. The cured state was good, and the entire surface was solidified and there was no liquid product.

Two SUS304 plates having such a hard coat film were prepared, and were opposed to each other so that the hard coat film side was inside. And the peripheral part was sealed with the gasket made from a soft polyvinyl chloride, and the casting_mold | template was produced.
Using this mold, a methacrylic resin laminate was obtained in the same manner as in Example 2-1.

  Moreover, when the layer which consists of a methacrylic-resin molded product of the methacrylic-resin laminated product of Example 2-2 was image | photographed with TEM, the same photograph as FIG. 5 was obtained, and the dye | stained sea part (dyed part) 43a The presence of an unstained island part (unstained part) 43b could be clearly confirmed.

(Example 2-3)
A methacrylic resin laminate was obtained in the same manner as in Example 2-1, except that the addition amount of methyl methacrylate was 18 parts and the addition amount of the multistage polymerization copolymer was 32 parts.
In addition, the obtained liquid mixture became a bowl-like substance whose viscosity was so increased that it could not be measured in the B-type viscosity system. Therefore, a methacrylic resin laminate was manufactured by sandwiching a bowl-shaped mixed solution (mixture) with a SUS304 plate on which a hard coat film was formed.

  Moreover, when the layer which consists of a methacrylic-type resin molded product of the methacrylic-type resin laminated product of Example 2-3 was image | photographed with TEM, the same photograph as FIG. 5 was obtained, and the dye | stained sea part (dyed part) 43a The presence of an unstained island part (unstained part) 43b could be clearly confirmed.

(Example 2-4)
A methacrylic resin laminate was obtained in the same manner as in Example 2-1, except that the multistage polymerization copolymer was changed to that produced in Production Example 3.
Moreover, when the layer which consists of a methacrylic-resin molded product of the methacrylic-resin laminated product of Example 2-4 was image | photographed with TEM, the same photograph as FIG. 5 was obtained, and the dye | stained sea part (dyed part) 43a The presence of an unstained island part (unstained part) 43b could be clearly confirmed.

(Example 2-5)
A methacrylic resin laminate was obtained in the same manner as in Example 2-1, except that the multistage polymerization copolymer was changed to that produced in Production Example 4.
Moreover, when the layer which consists of a methacrylic resin molded product of the methacrylic resin laminated product of Example 2-5 was image | photographed with TEM, the same photograph as FIG. 5 was obtained, and the dye | stained sea part (dyed part) 43a The presence of an unstained island part (unstained part) 43b could be clearly confirmed.

(Example 2-6)
A methacrylic resin laminate was obtained in the same manner as in Example 2-1, except that the multistage polymerization copolymer was changed to that produced in Production Example 5.
Moreover, when the layer which consists of a methacrylic resin molded product of the methacrylic resin laminated product of Example 2-6 was image | photographed with TEM, the same photograph as FIG. 5 was obtained, and the dye | stained sea part (dyed part) 43a The presence of an unstained island part (unstained part) 43b could be clearly confirmed.

(Example 2-7)
(1) Preparation of mixed liquid In a flask equipped with a stirring bar, 43.0 parts of methyl methacrylate, 50 parts of a partially polymerized methyl methacrylate similar to that used in Example 1-1, and 0.1 part of n-dodecyl mercaptan were added. While stirring at 500 rpm, 7.0 parts of the multistage polymerization copolymer obtained in Production Example 1 was added and stirred for 4 hours, 0.32 parts of t-hexylperoxypivalate was added and stirred for 5 minutes. Then, a mixed liquid having a viscosity of 3200 mPa · s was obtained.

(2) Manufacture of methacrylic resin laminate product After removing dissolved air under reduced pressure conditions for the obtained mixed solution, a thickness having a hard coat film on one surface in the same manner as in Example 2-1. A 3 mm methacrylic resin laminate was obtained.
Moreover, when the layer which consists of a methacrylic-resin molded product of the methacrylic-resin laminated product of Example 2-7 was image | photographed with TEM, the same photograph as FIG. 5 was obtained and the dye | stained sea part (dyed part) 43a The presence of an unstained island part (unstained part) 43b could be clearly confirmed.

(Example 2-8)
A methacrylic resin laminate was manufactured using the apparatus shown in FIGS. However, in this example, a hard coat film was formed on the lower endless belt.
The upper and lower endless belts were both made of SUS304 having a width of 2800 mm and a thickness of 1 mm and having a mirror finish. Moreover, these were arrange | positioned at intervals of 3.8 mm.
A 20 W / cm ² high pressure mercury lamp was used as a light source for irradiating and curing the coating film before curing formed on the endless belt.
A gasket made of soft polyvinyl chloride was used.
Then, using a metering pump, the liquid mixture was set so that the liquid mixture could be injected at a constant flow rate into the space surrounded by the endless belt and the gasket from the liquid mixture supply nozzle.
The coating film of the uncured mixed liquid to be injected on the hard coat film is cured by heating with a hot water shower, then heat-treated with a far-infrared heater, and further cooled by air blowing. The cooling means was set.

In this apparatus, the running of the endless belt was stopped, and the curable composition was applied onto the lower belt in the same manner as in Example 2-2 to form a coating film.
Thereafter, the endless belt was operated so that the coating film passed through a position 17 cm below the high-pressure mercury lamp at a speed of 2.5 m / min, and the coating film was cured to obtain a hard coat film. The cured state of the hard coat film was good, the entire surface was solidified, and there was no liquid material.
Next, the mixed solution prepared in the same manner as in Example 2-1 was supplied onto the hard coat film in the space formed by the endless belt and the gasket with a metering pump, and polymerized and cured for 45 minutes in a hot water shower at 78 ° C. Then, a heat treatment at 135 ° C. was performed for 30 minutes with a far-infrared heater and cooled to 85 ° C. over 10 minutes by air blowing. Then, the laminate was peeled from the endless belt.

  Moreover, when the layer which consists of a methacrylic resin molded product of the methacrylic resin laminated product of Example 2-8 was image | photographed with TEM, the same photograph as FIG. 5 was obtained, and the dye | stained sea part (dyed part) 43a The presence of an unstained island part (unstained part) 43b could be clearly confirmed.

(Experimental example 2-1)
The results of evaluating the scratch resistance of the same methacrylic resin molded product as in Example 1-1 are shown in Table 2.
The properties such as impact resistance were good, but the scratch resistance was lowered.

(Comparative Example 2-1)
In Example 2-1, a methacrylic resin laminate was obtained in the same manner as in Example 2-1, except that the amount of methyl methacrylate added was 50 parts, and the multistage polymerization copolymer was not added.

(Comparative Example 2-2)
A methacrylic resin molded article was obtained in the same manner as in Example 2-1, except that the multistage polymerization copolymer of Example 2-1 was changed to that produced in Production Example 6.
Moreover, when the layer which consists of a methacrylic resin molded product of the comparative example 2-2 was image | photographed with TEM, the same photograph as what is shown in FIG. 7 was obtained, and 2 steps | paragraphs of a multistage polymerization copolymer were obtained. In the stage, undyed island portions could not be confirmed in the sea portion of the dyed rubber-like copolymer.

  As is apparent from the results shown in Table 2, good evaluation was obtained in Example 2-1 to Example 2-8 according to the present invention, and in particular, evaluation of scratch resistance was compared with Experimental Example 2-1. In comparison with Example 2-1 to Comparative Example 2-4, it was very good, and it was confirmed that excellent scratch resistance was obtained.

It is explanatory drawing of the air knife method. It is explanatory drawing of the casting polymerization method. It is sectional drawing of the apparatus for performing a casting polymerization method continuously. It is a perspective view which shows the principal part of the apparatus shown in FIG. It is the photograph which image | photographed the methacrylic-type resin molded product or methacrylic-type resin laminated product of an Example with TEM. It is the photograph which image | photographed the methacrylic resin molded product of the Example with TEM. It is the photograph which image | photographed the methacrylic resin molded product or the methacrylic resin laminated product of the comparative example with TEM.

Explanation of symbols

40 Methacrylic resin part 42 Polymer obtained by first stage polymerization 43a Sea part (dyeing part)
43b Island part (unstained part)

Claims (12)

A methacrylic resin molded article containing a multistage polymerization copolymer including a rubbery copolymer having a crosslinked structure,
A methacrylic resin molded product in which a plurality of substantially spherical methacrylic resins are present in a rubbery copolymer.   The methacrylic resin molded product according to claim 1, wherein the gel content of the entire methacrylic resin molded product is 1.3 times or more of the gel content of the multistage polymerization copolymer.   The rubber-like copolymer is obtained by copolymerizing a raw material monomer containing 0.01 to 3 parts by mass of a polyfunctional polymerizable compound in 100 parts by mass of the raw material monomer of the rubber-like copolymer. The methacrylic resin molded product according to claim 1 or 2.   The methacrylic resin molded product according to any one of claims 1 to 3, wherein the content of the multistage polymerization copolymer is 4 to 30 parts by mass in 100 parts by mass of the methacrylic resin molded product. A method for producing a methacrylic resin molded product according to any one of claims 1 to 4,
A step of preparing a mixed solution by mixing a multi-stage polymerization copolymer including a rubbery copolymer having a crosslinked structure and a methyl methacrylate-based raw material;
Pouring the mixture into a mold and curing by casting polymerization;
A method for producing a methacrylic resin molded article having Preparing the mixed solution,
A step of preparing a dispersion (A) by dispersing a multi-stage polymerization copolymer in a methyl methacrylate-based raw material (B-1) containing a radically polymerizable monomer mainly composed of methyl methacrylate;
A methyl methacrylate raw material (B-) containing the dispersion (A) and a polymer of a radical polymerizable monomer mainly composed of methyl methacrylate and / or a radical polymerizable monomer mainly composed of methyl methacrylate. The method for producing a methacrylic resin molded article according to claim 5, further comprising a step of mixing 2).   The method for producing a methacrylic resin molded article according to claim 5 or 6, wherein the multistage polymerization copolymer recovered by spray drying is used.   A methacrylic resin laminate having a hard coat film and a layer comprising the methacrylic resin molded product according to claim 1. A method for producing a methacrylic resin laminate according to claim 8,
Forming a hard coat film in the mold;
A step of preparing a mixed solution by mixing a multi-stage polymerization copolymer including a rubbery copolymer having a crosslinked structure and a methyl methacrylate-based raw material;
Pouring the mixed solution into a mold on which the hard coat film is formed, and curing by a casting polymerization method;
A method for producing a methacrylic resin laminate having: A method for producing a methacrylic resin laminate according to claim 8,
A pair of endless belts that run facing each other at a predetermined interval; and a pair of gaskets that are provided near both ends of the pair of endless belts and that run following the endless belts. And forming a hard coat film on one or both surfaces of the pair of endless belts and a multi-stage comprising a rubbery copolymer having a cross-linked structure A step of mixing a polymerization copolymer and a methyl methacrylate raw material to prepare a mixed solution;
Supplying the mixed liquid continuously into the space of the molding apparatus and curing the mixture;
A method for producing a methacrylic resin laminate having: Preparing the mixed solution,
A step of preparing a dispersion (A) by dispersing a multi-stage polymerization copolymer in a methyl methacrylate-based raw material (B-1) containing a radically polymerizable monomer mainly composed of methyl methacrylate;
A methyl methacrylate-based raw material (B- The method for producing a methacrylic resin laminate according to claim 9 or 10, comprising a step of mixing 2). The method for producing a methacrylic resin laminate according to any one of claims 9 to 11, wherein a multistage copolymer recovered by spray drying is used.

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