JP2016008225A - Methacrylic resin composition, molded article, resin film, polarizer protective film, and retardation film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a methacrylic resin composition having excellent moldability, good heat resistance, high transparency, a small haze value, and good bending strength.SOLUTION: The methacrylic resin composition comprises: a first methacrylic resin (A) containing a methyl methacrylate unit (M) and at least one ring structure unit (R) having a ring structure in the main chain, selected from the group consisting of a lactone ring unit, maleic acid anhydride unit, glutaric acid anhydride unit, a glutarimide unit, N-substituted maleimide unit, and tetrahydropyran ring structure; and a block copolymer (B) comprising a methacrylate polymer block (b1) containing a methacrylate unit and an acrylate polymer block (b2) containing an acrylate unit. With respect to total 100 parts by mass of the component (A) and the component (B), the amount of the component (A) is 10 to 99 parts by mass and the amount of the component (B) is 90 to 1 parts by mass.

Description

The present invention relates to a methacrylic resin composition.
The present invention also relates to a molded article, a resin film, a polarizer protective film, and a retardation film using the methacrylic resin composition.

Various optical films such as a retardation film, a polarizer protective film, and a light diffusion film are used in the liquid crystal display device. As a material for such an optical film, a (meth) acrylic resin such as polymethyl methacrylate (PMMA) has been studied. In general, a film using a (meth) acrylic resin such as PMMA is excellent in transparency, but has low heat resistance and tends to be deformed by heat shrinkage.
For example, in applications such as a polarizer protective film and a retardation film, a stretching process is usually performed to obtain a desired retardation. At this time, if the heat resistance is insufficient, thermal shrinkage tends to occur.

Patent Documents 1 to 6 include a film using a (meth) acrylic resin in which a lactone ring unit, a maleic anhydride unit, a glutaric anhydride unit, a glutarimide unit, or an N-substituted maleimide unit is introduced into the main chain. It is disclosed.
Heat resistance can be improved by introducing a cyclic skeleton into the main chain. However, the (meth) acrylic resin having a cyclic skeleton in the main chain has a rigid main chain. Therefore, when used alone, the resin lacks flexibility and the processability is not good, the resulting film is brittle, and mechanical properties such as bending strength are insufficient.

In Patent Documents 7 to 9, a crosslinked rubber particle may be added in order to impart moderate flexibility to a film using a (meth) acrylic resin having a cyclic skeleton in the main chain and improve brittleness. Proposed. However, with the addition of the crosslinked rubber particles, the size of the crosslinked rubber particles is large with respect to the film thickness, the transparency of the film is lowered, and haze is particularly deteriorated. The surface smoothness of the film is also deteriorated.
In particular, when the stretching process is carried out, the film is thinned, but the crosslinked rubber particles are not flattened well and remain in the original size, thereby reducing the transparency. Therefore, when adding crosslinked rubber particles, it is practically difficult to carry out the stretching treatment. Even if the stretching treatment can be carried out, it is difficult to obtain a film having good transparency, haze, and surface smoothness.

  On the other hand, Patent Document 10 discloses a methacrylic acid ester polymer block (b1) and an acrylate polymer block (b2) for a general (meth) acrylic resin having no cyclic skeleton in the main chain. A methacrylic resin composition to which a block copolymer (B) is added is disclosed. This methacrylic resin composition is inferior in heat resistance as compared with a resin composition using a (meth) acrylic resin having a cyclic skeleton in the main chain.

International Publication No. 2006-112207 JP 2007-197703 A International Publication No. 2005-108438 JP 2013-033237 A Japanese Patent No. 5142938 International Publication No. 2014-021264 International Publication No. 2014-041803 JP 2010-126550 A JP 2010-96919 A International Publication No. 2014-073216

The present invention has been made in view of the above problems, and is a methacrylic resin composition having excellent molding processability, good heat resistance, high transparency, low haze, and good mechanical properties such as bending strength. And it aims at providing the molded object using the same.

The present invention provides the following methacrylic resin compositions.
The methacrylic resin composition of the present invention is
Selected from the group consisting of a structural unit (M) derived from methyl methacrylate and a lactone ring unit, maleic anhydride unit, glutaric anhydride unit, glutarimide unit, N-substituted maleimide unit, and tetrahydropyran ring structural unit. A first methacrylic resin (A) comprising at least one ring structural unit (R) having a ring structure in the main chain;
10 to 80% by mass of a methacrylic acid ester polymer block (b1) containing a structural unit derived from a methacrylic acid ester and 90 to 20% by mass of an acrylate polymer block (b2) containing a structural unit derived from an acrylate ester A block copolymer (B) containing
For the total amount of 100 parts by mass of the first methacrylic resin (A) and the block copolymer (B),
The amount of the first methacrylic resin (A) is 10 to 99 parts by mass,
The amount of the block copolymer (B) is 90 to 1 part by mass,
It is a methacrylic resin composition.

The present invention also provides a molded article comprising the above methacrylic resin composition of the present invention.
The present invention also provides a resin film comprising the above methacrylic resin composition of the present invention.
The present invention also provides a polarizer protective film comprising the above resin film of the present invention.
The present invention also provides a retardation film comprising the above resin film of the present invention.

In this specification, “film” refers to what is generally called a film or sheet.

  According to the present invention, a methacrylic resin composition having excellent molding processability, good heat resistance, high transparency, low haze, good mechanical properties such as bending strength, and a molded body using the same. Can be provided.

It is a schematic perspective view which shows the method of 3 point | piece bending evaluation of a film.

"Methacrylic resin composition"
The methacrylic resin composition of the present invention contains a first methacrylic resin (A) having a ring structure in the main chain and a block copolymer (B) as essential components.
The methacrylic resin composition of the present invention can contain a second methacrylic resin (C) having no ring structure in the main chain as an optional component, if necessary.

(First methacrylic resin (A))
The first methacrylic resin (A)
A structural unit (M) derived from methyl methacrylate;
At least one ring having a ring structure in the main chain, selected from the group consisting of a lactone ring unit, a maleic anhydride unit, a glutaric anhydride unit, a glutarimide unit, an N-substituted maleimide unit, and a tetrahydropyran ring structural unit And a structural unit (R).
The first methacrylic resin (A) may contain one or more other structural units.
The methacrylic resin composition of the present invention can contain one or more first methacrylic resins (A).

Hereinafter, the structural unit (M) derived from methyl methacrylate may be simply referred to as “methyl methacrylate unit (M)”.
The structural units derived from other monomers may be described in the same manner.

The production method of the first methacrylic resin (A) is not particularly limited, and a known method can be applied.
A method for carrying out a polymerization reaction by a known method using methyl methacrylate, a raw material monomer of the ring structural unit (R), if necessary, other monomers, and a raw material necessary for a polymerization reaction such as a polymerization disclosure agent Is mentioned.
As a known polymerization method,
Radical polymerization methods such as suspension polymerization, (continuous) bulk polymerization, solution polymerization, and emulsion polymerization;
And an anionic polymerization method.

In addition to the above-described method of polymerizing using a plurality of types of monomers including a monomer having a ring structure in advance, a methyl methacrylate unit (M) is contained by a known method, and the ring structure unit (R) is contained in the main chain. Alternatively, a method may be used in which a cyclic structure unit (R) is formed by introducing a ring structure into the main chain after the production of a methacrylic resin having no benzene.

  The method for producing the first methacrylic resin (A) is selected according to the type of the ring structural unit (R).

(Lactone ring unit)
The lactone ring unit is not particularly limited, and one or more known lactone ring units can be used.

The lactone ring is preferably a 4- to 8-membered ring, more preferably a 5- to 6-membered ring, and particularly preferably a 6-membered ring in terms of ease of production, production yield, and structural stability.

Examples of the 6-membered lactone ring unit include a structure represented by the following formula (1) and a structure described in JP-A No. 2004-168882. Among these, a structure represented by the following formula (1) is particularly preferable.

In formula (1), R ^{11 to} R ¹³ are each independently a hydrogen atom or an organic residue having 1 to 20 carbon atoms.

The organic residue is not particularly limited as long as it has 1 to 20 carbon atoms. For example, a linear or branched alkyl group, a linear or branched alkylene group, an aryl group, an -OAc group, And -CN group and the like. The organic residue may contain an oxygen atom.
In this specification, “Ac” represents an acetyl group.
When R ^{11 to} R ¹³ are organic residues, the carbon number is preferably 1 to 10, more preferably 1 to 5.

As the lactone ring unit, those represented by the following formula (1-A) are particularly preferred. In the formula, Me is a methyl group.

The manufacturing method in particular of 1st methacrylic resin (A) containing a lactone ring unit is not restrict | limited, A well-known method can be used.
A method in which a polymer having a hydroxyl group and an ester group in the molecular chain is obtained by the polymerization step, and the resulting polymer is subjected to a heat treatment to introduce a lactone ring structure into the polymer is preferred.

(Maleic anhydride unit)
The maleic anhydride unit is not particularly limited, and one or more known maleic anhydride units can be used.

For example, structural units of the resin described in International Publication No. 2014-02126 and a maleic acid-modified MAS resin (methyl methacrylate-acrylonitrile-styrene copolymer) are preferable.

  Examples of maleic acid-modified resins include (anhydrous) maleic acid-modified MS resin, (anhydrous) maleic acid-modified MAS resin (methyl methacrylate-acrylonitrile-styrene copolymer), (anhydrous) maleic acid-modified MBS resin, (anhydrous) Maleic acid modified AS resin, (anhydrous) maleic acid modified AA resin, (anhydrous) maleic acid modified ABS resin, ethylene-maleic anhydride copolymer, ethylene- (meth) acrylic acid-maleic anhydride copolymer, and anhydrous Examples include maleic acid grafted polypropylene.

As a maleic anhydride unit, the structure represented by following formula (2) is preferable.

In formula (2), R ²¹ and R ²² are each independently a hydrogen atom or an organic residue having 1 to 20 carbon atoms.

  The organic residue is not particularly limited as long as it has 1 to 20 carbon atoms. For example, a linear or branched alkyl group, a linear or branched alkylene group, an aryl group, an -OAc group, And -CN group and the like. The organic residue may contain an oxygen atom.

When R ²¹ and R ²² are organic residues, the carbon number thereof is preferably 1 to 10, more preferably 1 to 5.

When both R ²¹ and R ²² are hydrogen atoms, a copolymer component such as styrene is usually used from the viewpoint of ease of production and adjustment of intrinsic birefringence.

As the maleic anhydride unit, those represented by the following formula (2-A) are particularly preferred.

The manufacturing method in particular of the 1st methacrylic resin (A) containing a maleic anhydride unit is not restrict | limited, A well-known method can be used.

(Glutaric anhydride unit)
The glutaric anhydride unit is not particularly limited, and one or more known glutaric anhydride units can be used.

As the glutaric anhydride unit, a structure represented by the following formula (3) is preferable.

In formula (3), R ³¹ and R ³² are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

When R ³¹ and R ³² are organic residues, the carbon number thereof is preferably 1-10, more preferably 1-5.

As the glutaric anhydride unit, those represented by the following formula (3-A) are particularly preferable.

The manufacturing method in particular of the 1st methacrylic resin (A) containing a glutaric anhydride unit is not restrict | limited, A well-known method can be used.
After making an unsaturated carboxylic acid monomer that gives a glutaric anhydride unit and an unsaturated carboxylic acid alkyl ester monomer into a copolymer, the copolymer is heated in the presence of a catalyst as necessary to remove it. A method of performing an intramolecular cyclization reaction by alcohol and / or dehydration is preferable.

(Glutarimide unit)
It does not restrict | limit especially as a glutarimide unit, A 1 type, or 2 or more types can be used for a well-known thing.
As a glutarimide unit, the structure represented by following formula (4) is preferable.

In formula (4), R ⁴¹ and R ⁴² each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and R ⁴³ represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or 3 to 3 carbon atoms. 12 cycloalkyl groups or aryl groups having 6 to 10 carbon atoms.
As the glutarimide unit, R ⁴¹ and R ⁴² are each independently a hydrogen atom or a methyl group, and R ⁴³ is a hydrogen atom, a methyl group, or an n-butyl group from the viewpoint of raw material availability, cost, heat resistance, and the like. , A cyclohexyl group, or a benzyl group.
Particularly preferably, R ⁴¹ is a methyl group, R ⁴² is a hydrogen atom, and R ⁴³ is a methyl group, an n-butyl group, or a cyclohexyl group.

As the glutarimide unit, those represented by the following formula (4-A) are particularly preferable.

The manufacturing method in particular of the 1st methacrylic resin (A) containing a glutarimide unit is not restrict | limited, A well-known method can be used.

(N-substituted maleimide units)
The N-substituted maleimide unit is not particularly limited, and one or more known N-substituted maleimide units can be used.
As the N-substituted maleimide unit, a structure represented by the following formula (5) is preferable.

In formula (5), R ⁵¹ represents an arylalkyl group having 7 to 14 carbon atoms, an aryl group having 6 to 14 carbon atoms, or at least one substituent having at least one substituent selected from group B below. Of the aryl group.
R ⁵² and R ⁵³ are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 14 carbon atoms.
Group B is a group consisting of a halogen atom, a hydroxyl group, a nitro group, an alkoxy group having 1 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms, and an arylalkyl group having 7 to 14 carbon atoms.

As the N-substituted maleimide unit, those represented by the following formulas (5-A) and (5-B) are particularly preferable.

The production method of the first methacrylic resin (A) containing an N-substituted maleimide unit is not particularly limited, and a known method can be used.

(Tetrahydropyran ring structural unit)
The tetrahydropyran ring structural unit is not particularly limited, and one or more known ones can be used.
As the tetrahydropyran ring structural unit, a structure represented by the following formula (6) is preferable.

In formula (6), R ⁶¹ and R ⁶² each independently have a hydrogen atom, a linear hydrocarbon group having 1 to 20 carbon atoms, a branched hydrocarbon group having 1 to 20 carbon atoms, or a ring structure. It is a C3-C20 hydrocarbon group.

R ⁶¹ and R ⁶² are preferably each independently a group represented by the following formulas (6-R1) to (6-R4).
In the following formula, tBu is a tert-butyl group.

  Among the lactone ring unit, maleic anhydride unit, glutaric anhydride unit, glutarimide unit, N-substituted maleimide unit, and tetrahydropyran ring structural unit, the raw material availability and production of the first methacrylic resin (A) are easy. In view of properties and the like, a lactone ring unit or a maleic anhydride unit is preferable.

As described above, the first methacrylic resin (A) may contain one or more other structural units in addition to the methyl methacrylate unit (M) and the ring structural unit (R). .

The first methacrylic resin (A) includes a structural unit ((meth) acrylic monomer unit) derived from a (meth) acrylic monomer other than the methyl methacrylate monomer (M). Also good.
Examples of other (meth) acrylic monomers include:
Methacrylic acid such as ethyl methacrylate, cyclohexyl methacrylate, t-butyl methacrylate, isobornyl methacrylate, 8-tricyclo [5.2.1.0 ^2,6 ] decanyl methacrylate, and 4-t-butylcyclohexyl methacrylate Methacrylic acid alkyl esters other than methyl;
Alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate;
Acrylic acid aryl esters such as phenyl acrylate;
Acrylic acid cycloalkyl esters such as cyclohexyl acrylate and norbornenyl acrylate;
Examples thereof include vinyl monomers having only one polymerizable carbon-carbon double bond in one molecule such as (meth) acrylamide and (meth) acrylonitrile.
These (meth) acrylic monomers can be used alone or in combination of two or more.

The contents of the methyl methacrylate unit (M) and the ring structural unit (R) in the first methacrylic resin (A) are not particularly limited.
As the content of the ring structural unit (R) is increased, the heat resistance of the first methacrylic resin (A) is improved, but the main chain becomes rigid, the flexibility of the resin is lowered, and the phase with other resins is increased. There is a tendency for solubility and moldability to decrease.
Methyl methacrylate in the first methacrylic resin (A) from the viewpoints of heat resistance and molding processability of the methacrylic resin composition and compatibility between the first methacrylic resin (A) and other resins The content of the unit (M) is preferably 20% by mass or more, more preferably 50% by mass or more, and further preferably 70% by mass or more.
From the viewpoint of the heat resistance of the methacrylic resin composition and the compatibility between the first methacrylic resin (A) and other resins, the inclusion of the ring structural unit (R) in the first methacrylic resin (A) The amount is preferably 50% by mass or less, more preferably 40% by mass or less, and still more preferably 30% by mass or less.

  Physical properties of the first methacrylic resin (A) such as weight average molecular weight (Mw), molecular weight distribution, glass transition temperature (Tg), melt flow rate (MFR), and triplet display syndiotacticity (rr) Is not particularly limited, and is adjusted to a preferable range according to resin properties such as moldability and heat resistance.

In this specification, “weight average molecular weight (Mw) and number average molecular weight (Mn)” are values obtained by converting a chromatogram measured by gel permeation chromatography (GPC) into a molecular weight of standard polystyrene.
In the present specification, the “molecular weight distribution” is defined by the ratio between the weight average molecular weight (Mw) and the number average molecular weight (Mn), that is, Mw / Mn.

The weight average molecular weight (Mw) of the first methacrylic resin (A) is defined as “Mw (A)”. Mw (A) is preferably 40,000 to 200,000, more preferably 40,000 to 150,000, and particularly preferably 50,000 to 120,000.
When the Mw (A) is 40000 or more, the strength and toughness of the molded product obtained from the methacrylic resin composition of the present invention tend to be improved.
When Mw (A) is 200000 or less, the fluidity of the methacrylic resin composition of the present invention is improved, and the moldability tends to be improved accordingly.

The molecular weight distribution (Mw / Mn) of the first methacrylic resin (A) is preferably 1.2 to 5.0, more preferably 1.3 to 3.5.
When the molecular weight distribution (Mw / Mn) is 1.2 or more, the fluidity of the first methacrylic resin (A) is improved, and the resulting film tends to be excellent in surface smoothness and the like. When the molecular weight distribution (Mw / Mn) is 5.0 or less, the resulting film tends to be excellent in impact resistance, toughness, and the like.

  The first methacrylic resin (A) preferably has a melt flow rate (MFR) measured at 230 ° C. under a load of 3.8 kg in accordance with JIS K7210, preferably 0.1 to 20 g / 10 min. More preferably, it is 0.5-15 g / 10min, Most preferably, it is 1.0-10g / 10min.

The glass transition temperature (Tg) of the first methacrylic resin (A) is not particularly limited, and is preferably 120 ° C. or higher, more preferably 123 ° C. or higher, and particularly preferably 124 ° C. or higher.
The upper limit of the glass transition temperature (Tg) is not particularly limited, and is usually about 160 ° C.
When the glass transition temperature (Tg) is within the above range, the heat resistance of the first methacrylic resin (A) is good, and deformation such as heat shrinkage of the resulting film hardly occurs.

In this specification, “glass transition temperature (Tg)” is measured in accordance with JIS K7121. Specifically, the DSC curve is measured under the condition that the temperature is raised once to 230 ° C., then cooled to room temperature, and then raised from room temperature to 230 ° C. at 10 ° C./min. The intermediate point obtained from the DSC curve measured at the second temperature rise is obtained as “glass transition temperature (Tg)”.

  Various physical properties of the first methacrylic resin (A) can be adjusted by adjusting the copolymer composition, the weight average molecular weight (Mw), and the like.

The first methacrylic resin (A) can be used in combination of two or more as necessary in order to adjust physical properties such as weight average molecular weight (Mw), molding processability, and refractive index.
When a plurality of first methacrylic resins (A) are used, a plurality of first methacrylic resins (A) prepared individually may be blended by melt-kneading or prepared in advance. Another type of first methacrylic resin (A) may be polymerized using a monomer in the presence of one or more types of first methacrylic resin (A).

  In this invention, a 2nd methacrylic resin (C) can be used together as needed. In this case, instead of using a plurality of types of first methacrylic resins (A) having different physical properties such as weight average molecular weight (Mw), molding processability, and refractive index, weight average molecular weight (Mw), molding processability, In addition, the overall physical properties can be adjusted by using the first methacrylic resin (A) and the second methacrylic resin (C) having different physical properties such as refractive index.

(Block copolymer (B))
The block copolymer (B) includes a methacrylic acid ester polymer block (b1) and an acrylate polymer block (b2).
The number of the methacrylic ester polymer block (b1) in the block copolymer (B) is not particularly limited, and may be singular or plural.
Similarly, the number of acrylic ester polymer blocks (b2) in the block copolymer (B) is not particularly limited, and may be singular or plural.
The methacrylic resin composition of the present invention can contain one or more block copolymers (B).

The methacrylic ester polymer block (b1) is a polymer block containing a structural unit (methacrylic ester unit) derived from a methacrylic ester.
The ratio of the methacrylic acid ester unit in the methacrylic acid ester polymer block (b1) is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, and particularly preferably 98% by mass or more. is there.

The methacrylic acid ester is not particularly limited.
For example, methyl methacrylate (MMA), ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, amyl methacrylate, methacryl Isoamyl acid, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, pentadecyl methacrylate, dodecyl methacrylate, isobornyl methacrylate, phenyl methacrylate, benzyl methacrylate, phenoxyethyl methacrylate, 2-hydroxyethyl methacrylate , 2-methoxyethyl methacrylate, glycidyl methacrylate, and allyl methacrylate.
These methacrylic acid esters can form a methacrylic acid ester polymer block (b1) by polymerizing alone or in combination of two or more.
Among the above methacrylic acid esters, from the viewpoint of improving transparency and heat resistance, methyl methacrylate (MMA), ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, And alkyl methacrylates such as isobornyl methacrylate are preferred, and methyl methacrylate (MMA) is particularly preferred.

The methacrylic acid ester polymer block (b1) may contain a structural unit derived from a monomer other than the methacrylic acid ester as long as the object and effect of the present invention are not hindered.
The proportion of structural units derived from monomers other than methacrylate ester contained in the methacrylate polymer block (b1) is preferably 20% by mass or less, more preferably 10% by mass or less, and further preferably 5% by mass. Hereinafter, the range is particularly preferably 2% by mass or less.

The monomer other than methacrylic acid ester is not particularly limited.
For example, acrylic ester, unsaturated carboxylic acid, aromatic vinyl compound, olefin, conjugated diene, (meth) acrylonitrile, (meth) acrylamide, vinyl acetate, vinyl pyridine, vinyl ketone, vinyl chloride, vinylidene chloride, and vinylidene fluoride Is mentioned.
These monomers other than methacrylic acid ester can form a methacrylic acid ester polymer block (b1) by copolymerizing together with the above-mentioned methacrylic acid ester alone or in combination of two or more.

The methacrylic acid ester polymer block (b1) is preferably composed of a polymer having a refractive index (n _23D ) in the range of 1.485 to 1.495. Thereby, the transparency of the methacrylic resin composition of the present invention can be improved.

In this specification, “refractive index (n _23D )” means a value measured at a measurement wavelength of 587.6 nm (d-line) in an environment of relative humidity (RH) 50% and 23 ° C.

The weight average molecular weight Mw (b1) of the methacrylic acid ester polymer block (b1) is preferably 5000 to 150,000, more preferably 8000 to 120,000, and particularly preferably 12,000 to 100,000.
When the block copolymer (B) includes a plurality of methacrylate polymer blocks (b1), the weight average molecular weight Mw (b1) is the same for all methacrylate polymer blocks (b1). The weight average molecular weight is calculated and defined as the sum of the numerical values.

  When the block copolymer (B) contains a plurality of methacrylate polymer blocks (b1), the composition and molecular weight of the structural units constituting each methacrylate polymer block (b1) may be the same or not. Good.

The weight average molecular weight (Mw) of the first methacrylic resin (A) is defined as “Mw (A)”.
In the methacrylic resin composition of the present invention, Mw (A) / Mw (b1) is preferably 0.5 to 5.0, more preferably 1.0 to 4.0, and particularly preferably 1.2 to 3. 0.
If Mw (A) / Mw (b1) is too small, the impact resistance and the like of the molded product produced from the methacrylic resin composition tend to be lowered.
On the other hand, if Mw (A) / Mw (b1) is excessive, the surface smoothness and haze of the molded product produced from the methacrylic resin composition tend to deteriorate.
When Mw (A) / Mw (b1) is within the above range, the dispersed particle size of the block copolymer (B) in the methacrylic resin composition of the present invention is sufficiently small, and the surface smoothness and haze. Etc. become good.

  In addition, the weight average molecular weight (Mw) of each block of the methacrylic acid ester polymer block (b1) and the acrylate polymer block (b2) is an intermediate product and a final product in the production process of the block copolymer (B). It is calculated from the weight average molecular weight (Mw) of the block copolymer (B) which is a product.

From the viewpoint of transparency, flexibility, molding processability, surface smoothness and the like, the ratio of the methacrylic ester polymer block (b1) in the block copolymer (B) is 10 to 80% by mass, preferably 20 to 20%. It is 70 mass%, More preferably, it is 40-60 mass%.
When the proportion of the methacrylic acid ester polymer block (b1) in the block copolymer (B) is within the above range, the methacrylic resin composition of the present invention or a molded product made thereof has transparency, flexibility, Excellent physical properties such as flex resistance, impact resistance, and flexibility.

The acrylic ester polymer block (b2) is a polymer block containing a structural unit (acrylic ester unit) derived from an acrylic ester.
The ratio of the acrylate ester unit in the acrylate polymer block (b2) is preferably 45% by mass or more, more preferably 50% by mass or more, further preferably 60% by mass or more, and particularly preferably 90% by mass or more. .

Examples of the acrylic ester include
Methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, amyl acrylate, isoamyl acrylate, acrylic acid n-hexyl, cyclohexyl acrylate, 2-ethylhexyl acrylate, pentadecyl acrylate, dodecyl acrylate, isobornyl acrylate, phenyl acrylate, benzyl acrylate, phenoxyethyl acrylate, 2-hydroxyethyl acrylate, 2-acrylate Examples include methoxyethyl, glycidyl acrylate, and allyl acrylate.
An acrylic acid ester polymer block (b2) can be formed by polymerizing these acrylic acid esters alone or in combination of two or more.

  The acrylic ester polymer block (b2) may contain a structural unit derived from a monomer other than the acrylic ester as long as the object and effect of the present invention are not hindered. The proportion of structural units derived from monomers other than the acrylate ester contained in the acrylate polymer block (b2) is preferably 55% by mass or less, more preferably 50% by mass or less, and still more preferably 40% by mass. Hereinafter, it is particularly preferably 10% by mass or less.

As monomers other than acrylic esters, methacrylic esters, unsaturated carboxylic acids, aromatic vinyl compounds, olefins, conjugated dienes, (meth) acrylonitrile, (meth) acrylamides, vinyl acetate, vinyl pyridine, vinyl ketone, vinyl chloride , Vinylidene chloride, and vinylidene fluoride.
Monomers other than these acrylic esters can be used alone or in combination of two or more, and can be copolymerized with the above-mentioned acrylic ester to form the acrylic ester polymer block (b2).

  From the viewpoint of improving the transparency of the methacrylic resin composition, the acrylic ester polymer block (b2) is a non-aromatic structural unit derived from an acrylic ester having no aromatic ring (non-aromatic acrylic). Acid ester unit) and an aromatic structural unit derived from a (meth) acrylic acid ester having an aromatic ring (aromatic (meth) acrylic acid ester unit).

Examples of non-aromatic acrylic esters include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and dodecyl acrylate.
Of these, n-butyl acrylate, 2-ethylhexyl acrylate, and the like are preferable.

In this specification, “(meth) acrylic acid ester” means acrylic acid ester or methacrylic acid ester.
Aromatic (meth) acrylic acid esters are those in which an aromatic ring or a group containing it is ester-bonded to (meth) acrylic acid.
Examples of the aromatic (meth) acrylic acid ester include phenyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, and styryl (meth) acrylate.
Of these, phenyl methacrylate, benzyl (meth) acrylate, phenoxyethyl methacrylate, and the like are preferable.

  When the acrylic ester polymer block (b2) includes a non-aromatic acrylic ester unit and an aromatic (meth) acrylic ester unit, the acrylic ester polymer block (b2) is a non-aromatic acrylic ester unit. It preferably contains 50 to 90% by mass and 50 to 10% by mass of aromatic (meth) acrylate units, and 60 to 80% by mass of non-aromatic acrylate units and 40 units of aromatic (meth) acrylate units. More preferably, it contains ~ 20 mass%.

The acrylate polymer block (b2) is preferably composed of a polymer having a refractive index (n _23D ) in the range of 1.485 to 1.495. Thereby, the transparency of the methacrylic resin composition of the present invention can be improved.

The weight average molecular weight Mw (b2) of the acrylate polymer block (b2) is preferably 5,000 to 120,000, more preferably 15,000 to 110,000, and particularly preferably 30,000 to 100,000.
When the block copolymer (B) includes a plurality of acrylate polymer blocks (b2), the weight average molecular weight Mw (b2) is the same for all acrylate polymer blocks (b2). Each weight average molecular weight is calculated and defined as the sum of the numerical values.

  When there are a plurality of acrylate polymer blocks (b2) in the block copolymer (B), the composition and molecular weight of the structural units constituting each acrylate polymer block (b2) are the same or non-identical. Good.

When Mw (b2) is too small, the impact resistance and the like of the molded product produced from the methacrylic resin composition tend to be lowered. On the other hand, if Mw (b2) is excessive, the surface smoothness and the like of the molded product produced from the methacrylic resin composition tends to be lowered.

From the viewpoint of transparency, flexibility, moldability, surface smoothness, and the like, the ratio of the acrylate polymer block (b2) in the block copolymer (B) is preferably 20 to 90% by mass, more preferably. Is 30 to 80% by mass.
When the ratio of the acrylate polymer block (b2) in the block copolymer (B) is within the above range, the methacrylic resin composition of the present invention or a molded product made thereof has impact resistance, flexibility, etc. Excellent.

In the block copolymer (B), the bonding form of the methacrylic ester polymer block (b1) and the acrylate polymer block (b2) is not particularly limited.
Examples of the bonding form include a structure in which a methacrylic ester polymer block (b1) and an acrylate polymer block (b2) are connected in series.
As a coupling form connected in series, for example,
A methacrylic acid ester polymer block (b1) having one end connected to one end of an acrylic acid ester polymer block (b2) (a diblock copolymer having a (b1)-(b2) structure);
A triblock copolymer having a (b2)-(b1)-(b2) structure in which one end of an acrylate polymer block (b2) is connected to each of both ends of a methacrylate polymer block (b1) );
And acrylate polymer block (b2) having both ends connected to one end of methacrylic acid ester polymer block (b1) (triblock copolymer of (b1)-(b2)-(b1) structure) And the like).

As other coupling forms,
A block copolymer ([(b1)-(b2)-] nX structure) in which one end of a plurality of block copolymers having a (b1)-(b2) structure is connected to form a radial structure;
A block copolymer ([(b2)-(b1)-] nX structure) in which one end of a plurality of block copolymers having the structure (b2)-(b1) is connected to form a radial structure;
A block copolymer ([(b1)-(b2)-(b1)-] nX in which one terminal of a plurality of block copolymers having a structure (b1)-(b2)-(b1) is connected to form a radial structure) Construction);
And a block copolymer ([(b2)-(b1)-(b2)-]) in which a plurality of (b2)-(b1)-(b2) -structured block copolymers are linked to one end. nX structure) and the like.

  Other bonding forms include block copolymers having a branched structure.

  Note that X in the description of the bonding form is a coupling agent residue.

  Of the above bonding forms, diblock copolymers, triblock copolymers, and star block copolymers are preferred, and (b1)-(b2) -structured diblock copolymers, (b1)-(b2) -(B1) structure triblock copolymer, [(b1)-(b2)-] nX structure star block copolymer, and [(b1)-(b2)-(b1)-] nX structure Star block copolymers are more preferred.

The block copolymer (B) may have a polymer block (b3) other than the methacrylic acid ester polymer block (b1) and the acrylate polymer block (b2).
The main structural unit constituting the other polymer block (b3) is a structural unit derived from a monomer other than methacrylic acid ester and acrylic acid ester.
Examples of such monomers include:
Olefins such as ethylene, propylene, 1-butene, isobutylene, and 1-octene;
Conjugated dienes such as butadiene, isoprene, and myrcene;
Aromatic vinyl compounds such as styrene, α-methylstyrene, p-methylstyrene, and m-methylstyrene;
Examples include vinyl acetate, vinyl pyridine, acrylonitrile, methacrylonitrile, vinyl ketone, vinyl chloride, vinylidene chloride, vinylidene fluoride, acrylamide, methacrylamide, ε-caprolactone, and valerolactone.
These can be used alone or in combination of two or more.

In the block copolymer (B), the bonding form of the methacrylic ester polymer block (b1), the acrylate polymer block (b2), and the polymer block (b3) is not particularly limited.
As the bonding form, for example, a block copolymer having a structure (b1)-(b2)-(b1)-(b3) and a structure (b3)-(b1)-(b2)-(b1)-(b3) The block copolymer etc. are mentioned.
When there are a plurality of polymer blocks (b3) in the block copolymer (B), the composition and molecular weight of the structural units constituting each polymer block (b3) may be the same or non-identical.

  The block copolymer (B) may have a functional group such as a hydroxyl group, a carboxyl group, an acid anhydride, and an amino group in the molecular chain or at the molecular chain terminal as necessary.

Let the weight average molecular weight (Mw) of a block copolymer (B) be "Mw (B)." Mw (B) is preferably 32000 to 300000, more preferably 45000 to 230,000.
If Mw (B) is too small, sufficient melt tension cannot be maintained in melt extrusion molding, and it is difficult to obtain a good plate-like molded article, and mechanical properties such as breaking strength of the obtained plate-like molded article are lowered. Tend. On the other hand, if Mw (B) is excessive, the viscosity of the molten resin increases, and the surface of the plate-like molded body obtained by melt extrusion molding has fine wrinkle-like unevenness or unevenness due to unmelted material (high molecular weight body). Tends to occur, and it tends to be difficult to obtain a good plate-like molded body.

  The molecular weight distribution (Mw / Mn) of the block copolymer (B) is preferably 1.0 to 2.0, more preferably 1.0 to 1.6. By having a molecular weight distribution (Mw / Mn) within such a range, the content of unmelted material that causes the occurrence of blisters in the molded body made of the methacrylic resin composition of the present invention can be made extremely small. it can.

The refractive index (n _23D ) of the block copolymer (B) is preferably 1.485 to 1.495, more preferably 1.487 to 1.493. When the refractive index (n _23D ) is within this range, the transparency of the methacrylic resin composition of the present invention can be improved.

The manufacturing method of a block copolymer (B) is not specifically limited, A well-known method can be used.
For example, a method of living polymerizing monomers constituting each polymer block is preferable.
Examples of living polymerization methods include:
A method of anionic polymerization using an organic alkali metal compound as a polymerization initiator in the presence of a mineral acid salt such as an alkali metal or alkaline earth metal salt;
A method of anionic polymerization using an organic alkali metal compound as a polymerization initiator in the presence of an organic aluminum compound;
A method of polymerizing using an organic rare earth metal complex as a polymerization initiator;
and,
Examples include a method of radical polymerization using an α-halogenated ester compound as a polymerization initiator in the presence of a copper compound.
In addition, a method of producing a mixture containing a block copolymer (B) by polymerizing monomers constituting each block using a polyvalent radical polymerization initiator or a polyvalent radical chain transfer agent may be mentioned. .
Among these methods, in particular, the block copolymer (B) is obtained with high purity, the molecular weight and the composition are easily controlled, and economical, so that an organic alkali metal compound is used as a polymerization initiator. A method in which anionic polymerization is used in the presence of an organoaluminum compound is preferred.

(Second methacrylic resin (C))
The methacrylic resin composition of the present invention contains 70% by mass or more of a methyl methacrylate unit (M) as necessary, and includes a lactone ring unit, a maleic anhydride unit, a glutaric anhydride unit, a glutarimide unit, N A second methacrylic resin (C) not containing at least one ring structural unit (R) having a ring structure in the main chain, selected from the group consisting of a substituted maleimide unit and a tetrahydropyran ring structural unit Can be included.

As the second methacrylic resin (C),
A homopolymer of methyl methacrylate;
Examples include copolymers of methyl methacrylate with one or more other (meth) acrylic acid esters.
The second methacrylic resin (C) can contain one or more copolymerizable unsaturated monomer units other than the (meth) acrylic resin.
The methacrylic resin composition of the present invention can contain one or more second methacrylic resins (C).

  The composition and various physical properties of the second methacrylic resin (C) are determined by a combination with the first methacrylic resin (A) according to desired properties.

  From the viewpoint of moldability and compatibility with other resins, the second methacrylic resin (C) has a methyl methacrylate unit (M) content of 70% by mass or more, preferably 85% by mass. % Or more, more preferably 90% by mass or more, particularly preferably 95% by mass or more, and most preferably 100% by mass.

The lower limit of the syndiotacticity (rr) of the second methacrylic resin (C) is preferably 50%, more preferably 55%, still more preferably 58%, and particularly preferably 59%. And most preferably 60%.
From the viewpoint of film formability, the upper limit of the syndiotacticity (rr) of the second methacrylic resin (C) is preferably 99%, more preferably 85%, and even more preferably 77%. Particularly preferred is 65%, and most preferred is 64%.

The weight average molecular weight (Mw) of the second methacrylic resin (C) is defined as “Mw (C)”. Mw (C) is preferably 80,000 to 200,000, more preferably 85,000 to 160000, and particularly preferably 90000 to 120,000.
When Mw (C) is 80000 or more and syndiotacticity (rr) is 50% or more, the impact resistance, toughness, etc. of the molded product obtained from the methacrylic resin composition of the present invention tend to be improved. It becomes. Moreover, there exists a tendency for the moldability of the methacrylic-type resin composition of this invention to increase because Mw (C) of 2nd methacrylic-type resin (C) is 200000 or less.

The molecular weight distribution (Mw / Mn) of the second methacrylic resin (C) is preferably 1.2 to 5.0, more preferably 1.3 to 3.5.
When the molecular weight distribution (Mw / Mn) is 1.2 or more, the fluidity of the second methacrylic resin (C) is improved, and the resulting film tends to be excellent in surface smoothness and the like.
When the molecular weight distribution (Mw / Mn) is 5.0 or less, the resulting film tends to be excellent in impact resistance, toughness, and the like.

  The second methacrylic resin (C) preferably has a melt flow rate (MFR) measured at 230 ° C. under a load of 3.8 kg in accordance with JIS K7210, preferably 0.1 to 20 g / 10 min. More preferably, it is 0.5-15 g / 10min, Most preferably, it is 1.0-10g / 10min.

(Compounding ratio of components (A) to (C))
In the methacrylic resin composition of the present invention, heat resistance is improved by using the first methacrylic resin (A) having a cyclic skeleton in the main chain. Thereby, a film having a small heat shrinkage rate can be obtained. A film having a small heat shrinkage rate is preferable in that it does not easily shrink even when the stretching process is performed.
The first methacrylic resin (A) having a cyclic skeleton in the main chain alone lacks the flexibility of the resin and has poor mechanical properties such as moldability and bending strength.
In the present invention, by adding the block copolymer (B), flexibility is imparted and mechanical properties such as moldability and bending strength are improved.
Unlike the crosslinked rubber particles used in Patent Documents 7 to 9 listed in the “Background Art” section, the block copolymer (B) can sufficiently reduce the dispersed particle size in the resin composition. And does not adversely affect transparency, haze, surface smoothness, stretching treatment, and the like.
However, in the methacrylic resin composition of the present invention, if the amount of the first methacrylic resin (A) is too small, the effect of improving the heat resistance may not be sufficiently obtained. Further, if the amount of the block copolymer (B) is too small, the flexibility of the resin composition becomes insufficient, and there is a possibility that the mechanical properties such as molding processability and the bending strength of the molded article to be obtained are insufficient. is there.

In the methacrylic resin composition of the present invention, a second methacrylic resin (C) having no cyclic skeleton in the main chain can be used as necessary.
By using the second methacrylic resin (C), it is possible to improve the compatibility between the resins and the molding processability. Moreover, since the usage-amount of 1st methacrylic resin (A) which has a cyclic skeleton in the expensive principal chain with respect to the total usage-amount of methacrylic resin can be reduced, the resin composition can be reduced in cost.
If the amount of the second methacrylic resin (C) is too small, the above effect cannot be obtained effectively. In addition, if the amount of the second methacrylic resin (C) is excessive, the amount of the first methacrylic resin (A) having a cyclic skeleton in the main chain with respect to the total amount of methacrylic resin used is reduced. There is a risk that the effect of improving the property will be insufficient.

In the methacrylic resin composition of the present invention, preferred blending ratios of the components (A) to (C) are as follows.

When the methacrylic resin composition of the present invention does not contain the second methacrylic resin (C), the total amount of the first methacrylic resin (A) and the block copolymer (B) is 100 parts by mass. The amount of the first methacrylic resin (A) is 10 to 99 parts by mass, and the amount of the block copolymer (B) is 90 to 1 parts by mass.
Preferably, the amount of the first methacrylic resin (A) is 15 to 95 parts by mass, and the amount of the block copolymer (B) is 85 to 5 parts by mass.
Particularly preferably, the amount of the first methacrylic resin (A) is 75 to 95 parts by mass, and the amount of the block copolymer (B) is 25 to 5 parts by mass.

When the methacrylic resin composition of the present invention contains the second methacrylic resin (C),
For a total amount of 100 parts by mass of the first methacrylic resin (A), the block copolymer (B), and the second methacrylic resin (C),
The amount of the second methacrylic resin (C) is preferably more than 0 parts by mass and 70 parts by mass or less.

For a total amount of 100 parts by mass of the first methacrylic resin (A), the block copolymer (B), and the second methacrylic resin (C),
The total amount of the first methacrylic resin (A) and the second methacrylic resin (C) is 75 to 95 parts by mass,
The amount of the block copolymer (B) is more preferably 25 to 5 parts by mass.

(Polycarbonate resin (PC))
In applications such as polarizer protective film and retardation film,
Because adjustment of the phase difference is easy,
The methacrylic resin composition of the present invention preferably contains a polycarbonate resin (PC).

Polycarbonate resin (PC) is a polymer obtained by reaction of a polyfunctional hydroxy compound and a carbonate ester-forming compound.
The polycarbonate resin (PC) is preferably an aromatic polycarbonate resin from the viewpoint of compatibility with the methacrylic resins (A) and (C) and the transparency of the resulting film.

The method for producing the aromatic polycarbonate resin is not particularly limited, and examples thereof include a phosgene method (interfacial polymerization method) and a melt polymerization method (transesterification method).
The aromatic polycarbonate resin may be produced by subjecting a polycarbonate resin raw material produced in advance by a melt polymerization method to a treatment for adjusting the amount of terminal hydroxy groups.

The polyfunctional hydroxy compound is not particularly limited,
4,4′-dihydroxybiphenyls;
Bis (hydroxyphenyl) alkanes;
Bis (4-hydroxyphenyl) ethers;
Bis (4-hydroxyphenyl) sulfides;
Bis (4-hydroxyphenyl) sulfoxides;
Bis (4-hydroxyphenyl) sulfones;
Bis (4-hydroxyphenyl) ketones;
Bis (hydroxyphenyl) fluorenes;
Dihydroxy-p-terphenyls; dihydroxy-p-quarterphenyls;
Bis (hydroxyphenyl) pyrazines;
Bis (hydroxyphenyl) menthanes;
Bis [2- (4-hydroxyphenyl) -2-propyl] benzenes;
Dihydroxynaphthalene;
Dihydroxybenzenes;
Polysiloxanes;
and,
And dihydroperfluoroalkanes.
Any of these may have a substituent.
These can be used alone or in combination of two or more.

Among these polyfunctional hydroxy compounds, 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclohexane, bis (4-hydroxyphenyl) diphenylmethane, 1,1-bis ( 4-hydroxyphenyl) -1-phenylethane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-hydroxy-3-phenylphenyl) propane, 4,4′- Dihydroxybiphenyl, bis (4-hydroxyphenyl) sulfone, 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane, 3,3-bis (4-hydroxyphenyl) pentane, 9,9-bis ( 4-hydroxy-3-methylphenyl) fluorene, bis (4-hydroxyphenyl) ether, 4,4 '-Dihydroxybenzophenone, 2,2-bis (4-hydroxy-3-methoxyphenyl) 1,1,1,3,3,3-hexafluoropropane, α, ω-bis [3- (2-hydroxyphenyl) Propyl] polydimethylsiloxane, resorcin, 2,7-dihydroxynaphthalene and the like are preferable.
In particular, 2,2-bis (4-hydroxyphenyl) propane and the like are preferable.

The carbonate ester-forming compound is not particularly limited,
Various dihalogenated carbonyls such as phosgene;
Haloformates such as chloroformate;
And carbonic acid ester compounds such as bisaryl carbonate.
These can be used alone or in combination of two or more.
The amount of the carbonic acid ester forming compound is appropriately adjusted in consideration of the stoichiometric ratio (equivalent) of the reaction.

The reaction between the polyfunctional hydroxy compound and the carbonate ester-forming compound is usually performed in a solvent in the presence of an acid binder.
As an acid binder,
Alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, lithium hydroxide, and cesium hydroxide;
Alkali metal carbonates such as sodium carbonate and potassium carbonate;
Tertiary amines such as trimethylamine, triethylamine, tributylamine, N, N-dimethylcyclohexylamine, pyridine, and dimethylaniline;
Quaternary ammonium salts such as trimethylbenzylammonium chloride, triethylbenzylammonium chloride, tributylbenzylammonium chloride, trioctylmethylammonium chloride, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylphosphonium chloride, and tetrabutylphosphonium bromide Grade phosphonium salts and the like.
These can be used alone or in combination of two or more.
The amount of the acid binder may be appropriately adjusted in consideration of the stoichiometric ratio (equivalent) of the reaction.
Specifically, 1 equivalent or an excess amount, preferably 1 to 5 equivalents of acid binder can be used per 1 mol of hydroxyl group of the starting polyfunctional hydroxy compound.

If necessary, a small amount of an antioxidant such as sodium sulfite and hydrosulfide may be added to the reaction system.

In the reaction of the polyfunctional hydroxy compound and the carbonate ester-forming compound, a known end terminator can be used as necessary.

As the terminator, p-tert-butyl-phenol, p-phenylphenol, p-cumylphenol, p-perfluorononylphenol, p- (perfluorononylphenyl) phenol, p- (perfluoroxylphenyl) phenol , P-tert-perfluorobutylphenol, 1- (P-hydroxybenzyl) perfluorodecane, p- [2- (1H, 1H-perfluorotridodecyloxy) -1,1,1,3,3,3- Hexafluoropropyl] phenol, 3,5-bis (perfluorohexyloxycarbonyl) phenol, perfluorododecyl p-hydroxybenzoate, p- (1H, 1H-perfluorooctyloxy) phenol, 2H, 2H, 9H-par Fluorononanoic acid and 1,1,1,3 , 3 Tetorafuroro-2-propanol.
These can be used alone or in combination of two or more.

A known branching agent can be used in the reaction of the polyfunctional hydroxy compound and the carbonate ester-forming compound, if necessary.
Examples of branching agents include phloroglysin, pyrogallol, 4,6-dimethyl-2,4,6-tris (4-hydroxyphenyl) -2-heptene, 2,6-dimethyl-2,4,6-tris (4- Hydroxyphenyl) -3-heptene, 2,4-dimethyl-2,4,6-tris (4-hydroxyphenyl) heptane, 1,3,5-tris (2-hydroxyphenyl) benzene, 1,3,5- Tris (4-hydroxyphenyl) benzene, 1,1,1-tris (4-hydroxyphenyl) ethane, tris (4-hydroxyphenyl) phenylmethane, 2,2-bis [4,4-bis (4-hydroxyphenyl) ) Cyclohexyl] propane, 2,4-bis [2-bis (4-hydroxyphenyl) -2-propyl] phenol, 2,6-bis (2-hydroxy-) -Methylbenzyl) -4-methylphenol, 2- (4-hydroxyphenyl) -2- (2,4-dihydroxyphenyl) propane, tetrakis (4-hydroxyphenyl) methane, tetrakis [4- (4-hydroxyphenylisopropyl) ) Phenoxy] methane, 2,4-dihydroxybenzoic acid, trimesic acid, cyanuric acid, 3,3-bis (3-methyl-4-hydroxyphenyl) -2-oxo-2,3-dihydroindole, 3,3- Bis (4-hydroxyaryl) oxindole, 5-chloroisatin, 5,7-dichloroisatin, 5-bromoisatin and the like can be mentioned.
These can be used alone or in combination of two or more.

  The polycarbonate resin (PC) may contain one or more other polymer units such as a polyester unit, a polyurethane unit, a polyether unit, or a polysiloxane unit in addition to the polycarbonate unit.

The polycarbonate resin (PC) is compatible with the first methacrylic resin (A) and the second methacrylic resin (C), the transparency and in-plane uniformity of the obtained film, and the polycarbonate resin (PC). from the viewpoint of bleed-out suppressed, 300 ° C., 1.2 kg load, melt volume flow rate to be measured in 10 min conditions (MVR) is preferably 1.0~2 × 10 ⁷ cm ^3/10 min, more preferably the 10~1 × 10 ⁵ cm ^3/10 min, more preferably 25~10000cm ^3/10 min, particularly preferably 33~390cm ^3/10 min.

  The weight average molecular weight (Mw) of the polycarbonate resin (PC) is preferably 1300 to 75000, more preferably 4700 to 48300, still more preferably 8500 to 38200, and particularly preferably 19200 to 35700.

  The MVR and the weight average molecular weight (Mw) of the polycarbonate resin (PC) can be controlled by adjusting the amounts of the terminal stopper and the branching agent in the production of the polycarbonate resin (PC).

  The glass transition temperature (Tg) of the polycarbonate resin (PC) is preferably 130 ° C. or higher, more preferably 135 ° C. or higher, and particularly preferably 140 ° C. or higher. The upper limit of the glass transition temperature (Tg) of the polycarbonate resin (PC) is usually 180 ° C.

When the methacrylic resin composition of the present invention does not contain the second methacrylic resin (C),
The amount of the polycarbonate resin (PC) is preferably 1 to 10 parts by mass, more preferably 2 to 100 parts by mass of the total amount of the first methacrylic resin (A) and the block copolymer (B). 7 parts by mass, particularly preferably 3 to 6 parts by mass.

When the methacrylic resin composition of the present invention contains the second methacrylic resin (C),
The amount of the polycarbonate resin (PC) is preferably 1 with respect to 100 parts by mass of the total amount of the first methacrylic resin (A), the block copolymer (B) and the second methacrylic resin (C). -10 parts by mass, more preferably 2-7 parts by mass, particularly preferably 3-6 parts by mass.

In applications such as a polarizer protective film and a retardation film, a film having a small retardation in the thickness direction can be obtained. Therefore, the amount of the polycarbonate resin (PC) in the methacrylic resin composition of the present invention is preferably 1. -9% by mass, more preferably 2-7% by mass, particularly preferably 3-6% by mass.

(Other ingredients)
The methacrylic resin composition of the present invention can contain optional components other than those described above, if necessary. The methacrylic resin composition of the present invention can contain one or more other resins. The methacrylic resin composition of the present invention can contain one or more kinds of various additives.

Other polymers include:
Polyolefin resins such as polyethylene, polypropylene, polybutene-1, poly-4-methylpentene-1, and polynorbornene;
Ethylene ionomers;
Styrene resins such as polystyrene, styrene-maleic anhydride copolymer, high impact polystyrene, AS resin, ABS resin, AES resin, AAS resin, ACS resin, and MBS resin;
Polyester resins such as polyethylene terephthalate and polybutylene terephthalate;
Polyamides such as nylon 6, nylon 66, and polyamide elastomers;
Polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and polyvinylidene fluoride;
Polyacetal;
Polyurethane;
Modified polyphenylene ether and polyphenylene sulfide;
Silicone modified resin;
Acrylic rubber and silicone rubber;
Styrenic thermoplastic elastomers such as SEPS, SEBS, and SIS;
And olefinic rubbers such as IR, EPR, and EPDM.

The amount of the other polymer that can be contained in the methacrylic resin composition of the present invention is preferably 10% by mass or less, more preferably 5% by mass or less, and most preferably 0% by mass.

Additives include fillers, antioxidants, thermal degradation inhibitors, UV absorbers, light stabilizers, lubricants, mold release agents, polymer processing aids, antistatic agents, flame retardants, dyes and pigments, light diffusing agents, Organic dyes, matting agents, phosphors and the like can be mentioned.

The antioxidant alone has an effect of preventing oxidative deterioration of the resin in the presence of oxygen.
Examples thereof include phosphorus antioxidants, hindered phenol antioxidants, and thioether antioxidants. These antioxidants can be used alone or in combination of two or more.
Among these, from the viewpoint of the effect of preventing deterioration of optical properties due to coloring, a phosphorus-based antioxidant and a hindered phenol-based antioxidant are preferable, and a combined use of a phosphorus-based antioxidant and a hindered phenol-based antioxidant is more preferable. .
When using together phosphorus antioxidant and hindered phenolic antioxidant, the usage-amount of phosphorus antioxidant: The usage-amount of hindered phenolic antioxidant is 1: 5-2 by mass ratio. 1 is preferable, and 1: 2 to 1: 1 is more preferable.

  Examples of phosphorus antioxidants include 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite (manufactured by ADEKA; trade name: ADK STAB HP-10), tris (2,4-di-t- Butylphenyl) phosphite (manufactured by BASF; trade name: IRGAFOS168) and 3,9-bis (2,6-di-tert-butyl-4-methylphenoxy) -2,4,8,10-tetraoxa3 9-diphosphaspiro [5.5] undecane (manufactured by ADEKA; trade name: ADK STAB PEP-36) and the like are preferable.

  As the hindered phenol-based antioxidant, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (manufactured by BASF; trade name IRGANO01010), and octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate (manufactured by BASF; trade name IRGANO01076) is preferred.

The thermal degradation inhibitor can prevent thermal degradation of the resin by scavenging polymer radicals generated when exposed to high heat in a substantially oxygen-free state.
As the thermal degradation inhibitor, 2-t-butyl-6- (3′-t-butyl-5′-methyl-hydroxybenzyl) -4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd .; trade name Sumilyzer GM), and 2,4-di-t-amyl-6- (3 ′, 5′-di-t-amyl-2′-hydroxy-α-methylbenzyl) phenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd .; trade name Sumitizer GS) and the like are preferable.

The ultraviolet absorber is a compound having an ability to absorb ultraviolet rays. The ultraviolet absorber is a compound that is said to have a function of mainly converting light energy into heat energy.
Examples of the ultraviolet absorber include benzophenones, benzotriazoles, triazines, benzoates, salicylates, cyanoacrylates, succinic anilides, malonic esters, and formamidines.
These can use 1 type (s) or 2 or more types.
Among these, benzotriazoles, triazines, or ultraviolet absorbers having a maximum molar extinction coefficient ε _{max at a} wavelength of 380 to 450 nm of 1200 dm ³ · mol ⁻¹ cm ⁻¹ or less are preferable.

Benzotriazoles are highly effective in suppressing deterioration of optical properties such as coloring due to ultraviolet irradiation.
As benzotriazoles,
2- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol (manufactured by BASF; trade name TINUVIN329),
2- (2H-benzotriazol-2-yl) -4,6-bis (1-methyl-1-phenylethyl) phenol (manufactured by BASF; trade name TINUVIN234),
and,
2,2′-methylenebis [6- (2H-benzotriazol-2-yl) -4-tert-octylphenol] (manufactured by ADEKA; LA-31) is preferred.

An ultraviolet absorber having a maximum molar extinction coefficient ε _{max at a} wavelength of 380 to 450 nm of 1200 dm ³ · mol ⁻¹ cm ⁻¹ or less can suppress yellowness of the resulting molded article. Examples of such an ultraviolet absorber include 2-ethyl-2′-ethoxy-oxalanilide (manufactured by Clariant Japan, trade name: Sundebore VSU).

Among the above-described ultraviolet absorbers, benzotriazoles and the like are preferably used from the viewpoint that resin degradation due to ultraviolet irradiation can be suppressed.

Further, when it is desired to efficiently absorb a wavelength around 380 nm, a triazine ultraviolet absorber is preferably used.
As such an ultraviolet absorber,
2,4,6-tris (2-hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine (manufactured by ADEKA; LA-F70),
And hydroxyphenyltriazine-based ultraviolet absorbers (manufactured by BASF; TINUVIN477-D and TINUVIN460) which are analogs thereof.

In addition, the maximum value ε _max of the molar extinction coefficient of the ultraviolet absorber is measured as follows.
Add 10.00 mg of UV absorber to 1 L of cyclohexane and dissolve it so that there is no undissolved material by visual observation. This solution is poured into a 1 cm × 1 cm × 3 cm quartz glass cell, and the absorbance at a wavelength of 380 to 450 nm is measured using a U-3410 spectrophotometer manufactured by Hitachi, Ltd. The maximum value ε _max of the molar extinction coefficient is calculated from the molecular weight (M _UV ) of the ultraviolet absorber and the maximum value (A _max ) of the measured absorbance according to the following formula.

ε _max = [A _max / (10 × 10 ⁻³ )] × M _UV

As the polymer processing aid, polymer particles having a particle diameter of 0.05 to 0.5 μm, usually produced by an emulsion polymerization method, are used. Such polymer particles may be single layer particles composed of a single composition and single intrinsic viscosity polymer, or may be multilayer particles composed of two or more polymers having different compositions or intrinsic viscosities. .
In particular, particles having a two-layer structure having a polymer layer having a relatively low intrinsic viscosity in the inner layer and a polymer layer having a relatively high intrinsic viscosity of 5 dl / g or more in the outer layer are preferable.
Specifically, the Metablene-P series manufactured by Mitsubishi Rayon Co., Ltd., the Paraloid series manufactured by Rohm and Haas Co., etc. are preferable.
The polymer processing aid preferably has an intrinsic viscosity of 3 to 6 dl / g. If the intrinsic viscosity is too small, the effect of improving the molding processability of the methacrylic resin composition of the present invention tends to be low. If the intrinsic viscosity is excessive, the molding processability of the methacrylic resin composition of the present invention tends to be lowered.

  The total amount of additives that can be contained in the methacrylic resin composition of the present invention is preferably 7% by mass or less, more preferably 5% by mass or less, and particularly preferably 4% by mass or less.

(Production method and physical properties of methacrylic resin composition)
The method for producing the methacrylic resin composition of the present invention is not particularly limited.
For example, the methacrylic resin composition of the present invention is prepared by preparing plural kinds of constituent resins including the first methacrylic resin (A) and the block copolymer (B), and melt-kneading these plural kinds of constituent resins. Can be manufactured.
The melt-kneading can be performed using, for example, a melt-kneader such as a kneader ruder, an extruder, a mixing roll, and a Banbury mixer.
The kneading temperature is appropriately adjusted according to the softening temperature of the resin component, and is usually preferably in the range of 150 ° C to 300 ° C.

Instead of the above method, one or more types of constituent resins of the plurality of types of constituent resins including the first methacrylic resin (A) and the block copolymer (B) are prepared. A method of polymerizing other types of constituent resins in the presence may also be used.
For example, the first methacrylic resin (A) can be polymerized in the presence of the block copolymer (B). This method eliminates the need for a melt-kneading step, so that the thermal history applied to the first methacrylic resin (A) is shorter than that in the above method. Therefore, thermal decomposition of the first methacrylic resin (A) is suppressed, and a molded body with less coloring and foreign matter is easily obtained.

The weight average molecular weight (Mw) of the methacrylic resin composition of the present invention is preferably 32000 to 300000, more preferably 45000 to 230,000, and particularly preferably 60000 to 200000.
The molecular weight distribution (Mw / Mn) of the methacrylic resin composition of the present invention is preferably 1.2 to 2.5, more preferably 1.3 to 2.0.
When the weight average molecular weight (Mw) and the molecular weight distribution (Mw / Mn) are within the above ranges, the molding processability of the methacrylic resin composition of the present invention is improved, and a molded article excellent in impact resistance and toughness is obtained. It becomes easy to obtain.

  The melt flow rate (MFR) determined by measuring the methacrylic resin composition of the present invention at 230 ° C. and a load of 3.8 kg is preferably 0.1 g / 10 min or more, more preferably 0.2 to 30 g / 10 min, more preferably 0.5 to 20 g / 10 min, and particularly preferably 1.0 to 10 g / 10 min.

  The glass transition temperature (Tg) of the methacrylic resin composition of the present invention is preferably 120 ° C. or higher, more preferably 123 ° C. or higher, and still more preferably 124 ° C. or higher. The upper limit of the glass transition temperature (Tg) of the methacrylic resin composition is not particularly limited, and is preferably 140 ° C.

  The methacrylic resin composition of the present invention can be in the form of pellets or the like in order to enhance convenience during storage, transportation or molding.

According to the present invention, it is possible to provide a methacrylic resin composition having excellent molding processability, good heat resistance, high transparency, low haze, and good mechanical properties such as bending strength.

(Molded body)
The molded body of the present invention is formed by molding the above methacrylic resin composition of the present invention.
The manufacturing method of the molded object of this invention is not specifically limited.
For example, T-die method (lamination method, co-extrusion method, etc.), inflation method (co-extrusion method, etc.), compression molding method, blow molding method, calendar molding method, vacuum molding method, and injection molding method (insert method, second method) Melt molding methods such as color method, press method, core back method and sandwich method;
And a solution casting method.
Among the above methods, the T die method, the inflation method, the injection molding method, and the like are preferable from the viewpoint of high productivity and cost.

The form of the molded body of the present invention is not particularly limited.
One form of the molded body of the present invention is a resin film.

The resin film of the present invention can be produced by a solution casting method, a melt casting method, an extrusion molding method, an inflation molding method, a blow molding method, or the like.
Of these methods, an extrusion method or the like is preferable from the viewpoints of transparency, toughness, and handleability. The temperature of the methacrylic resin composition discharged from the extruder is preferably 160 to 270 ° C, more preferably 220 to 260 ° C.

Among the extrusion molding methods, a film having good surface smoothness, good specular gloss, and low haze can be obtained. Therefore, the methacrylic resin composition is extruded from a T die in a molten state, and then it is paired with a pair of specular rolls or A method including a step of forming by sandwiching with a mirror belt is preferable.
The thickness of the resin film (unstretched film) obtained by extrusion molding is preferably 10 to 300 μm. The haze of the resin film (unstretched film) obtained by extrusion molding is preferably 0.5% or less, more preferably 0.3% or less at a thickness of 100 μm.

You may perform an extending | stretching process with respect to the resin film (unstretched film) obtained by extrusion molding. By the stretching treatment, a film that has high mechanical strength and is difficult to crack can be obtained.
In applications such as a retardation film, desired retardation characteristics can be expressed by stretching.
Since the methacrylic resin composition of the present invention has good heat resistance and a small thermal shrinkage rate, the thermal shrinkage in the stretching process is small, and a high-quality stretched film can be obtained.

The stretching method is not particularly limited, and examples thereof include uniaxial stretching, simultaneous biaxial stretching, sequential biaxial stretching, and tuber stretching.
Since the film can be uniformly stretched and a high-strength film can be obtained, the stretching temperature is preferably 100 to 200 ° C, more preferably 120 to 160 ° C. Usually, the stretching speed is 100 to 5000% / min on a length basis. A film with little heat shrinkage can be obtained by performing heat setting after the stretching treatment.
In applications such as a polarizer protective film and a retardation film, a stretched film that is stretched in at least one direction by an area ratio of 1.5 to 8 times is preferable.

  The thickness of the resin film of the present invention is not particularly limited, and is preferably 1 to 300 μm, more preferably 10 to 50 μm, and particularly preferably 15 to 40 μm in applications such as an optical film.

  The haze at a thickness of 50 μm of the resin film of the present invention is not particularly limited, and is preferably 0.2% or less, more preferably 0.1% or less. A resin film having such characteristics is excellent in transparency and surface gloss.

The resin film of the present invention can be used for applications such as a polarizer protective film and a retardation film.
In the above application, the resin film of the present invention preferably has an in-plane retardation Re with respect to light having a wavelength of 590 nm, when the film thickness is 40 μm, preferably 0 to 5 nm, more preferably 0 to 4 nm, and still more preferably 0 to 0 nm. 3 nm, particularly preferably 0 to 2 nm, particularly preferably 0 to 1 nm.
In the above applications, the resin film of the present invention preferably has a thickness direction retardation Rth of 590 nm for light having a wavelength of 40 μm, preferably −5 to 5 nm, more preferably −4 to 4 nm, and even more preferably. It is −3 to 3 nm, particularly preferably −2 to 2 nm, and particularly preferably −1 to 1 nm.
If the in-plane phase difference Re and the thickness direction phase difference Rth are within the above ranges, the influence on the display characteristics of the image display apparatus due to the phase difference can be remarkably suppressed. Specifically, interference unevenness or distortion of a 3D image when used for a liquid crystal display element for 3D display can be significantly suppressed.

The in-plane direction phase difference Re and the thickness direction phase difference Rth are defined by the following equations, respectively.
Re = (nx−ny) × d,
Rth = ((nx + ny) / 2−nz) × d
Here, nx is the refractive index in the slow axis direction of the film, ny is the refractive index in the fast axis direction of the film, nz is the refractive index in the thickness direction of the film, and d (nm) is the film. Is the thickness. The slow axis refers to the direction in which the in-plane refractive index is maximized, and the fast axis refers to the direction perpendicular to the slow axis in the plane.

The molded product and the resin film of the present invention can be used for any application.
The molded article and resin film of the present invention have high transparency, low haze, good heat resistance, and good mechanical properties such as bending strength.
The molded article and resin film of the present invention having the above characteristics are:
It is preferably used for an optical element such as a liquid crystal display, an electroluminescence (EL) display, a plasma display, a touch panel, and electronic paper, and a component of an electronic apparatus including such an optical element.
In the optical element or the electronic apparatus including the same, the molded body and the resin film of the present invention are, for example, a substrate, a front plate, a surface material, a surface protective film, a light guide film, a polarizing film, a polarizer protective film, a retardation film (Also called optical compensation film), wave plate, viewing angle widening film, light diffusion film, prism film, reflection film, antireflection film (antiglare film), brightness enhancement film, silver nanowire or carbon nanotube were coated on the surface It can be used for a transparent conductive film, a spacer between various modules, and the like.

Others of the molded body and the resin film of the present invention,
Finders such as cameras, VTRs, and projection TVs;
Various optical disk substrates and protective films thereof;
Optical switches and optical connectors;
Various optical filters;
It is preferably used in various optical applications such as various optical lenses such as Fresnel lenses.

  The resin film of the present invention preferably containing a polycarbonate resin (PC) can have good retardation characteristics in accordance with the above characteristics. The resin film of the present invention having good retardation characteristics can be preferably used for a polarizer protective film, a retardation film and the like.

Since the resin film of the present invention has good transparency, heat resistance, mechanical properties, etc., in addition to optical applications, infrared cut film, crime prevention film, scattering prevention film, decorative film, solar cell backsheet It can be suitably used for a flexible solar cell front sheet, a shrink film, an in-mold label film, and the like.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited to the following Example. The physical property values and the like were measured by the following method.

(Polymerization conversion)
The gas chromatograph GC-14A manufactured by Shimadzu Corporation was used as a column for GL Sciences Inc. Inert CAP 1 (df = 0.4 μm, ID = 0.25 mm, length = 60 m) was connected. The injection temperature was 180 ° C. and the detector temperature was 180 ° C. The column temperature was kept at 60 ° C. for 5 minutes, and then the temperature profile was raised from 60 ° C. to 200 ° C. at a rate of temperature increase of 10 ° C./min, and held at 200 ° C. for 10 minutes. Measurement was performed under these conditions, and the polymerization conversion was calculated based on the obtained results.

(Weight average molecular weight (Mw), molecular weight distribution (Mw / Mn))
The weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) were calculated by measuring the chromatogram under the following conditions by gel permeation chromatography (GPC) and converting to the molecular weight of standard polystyrene.
As the GPC apparatus, “HLC-8320” manufactured by Tosoh Corporation was used. A differential refractive index detector was used as the detector. As the column, a column in which two “TSKgel SuperMultipore HZM-M” manufactured by Tosoh Corporation and “SuperHZ4000” were connected in series was used. Tetrahydrofuran (THF) was used as the eluent. The eluent flow rate was 0.35 ml / min. The column temperature was 40 ° C. A calibration curve was prepared using data of 10 standard polystyrene points.
The baseline of the chromatogram shows that the slope of the peak on the high molecular weight side of the GPC chart changes from zero to positive when viewed from the earlier retention time, and the slope of the peak on the lower molecular weight side is viewed from the earlier retention time. This is a line connecting points that change from minus to zero.

(Glass transition temperature (Tg))
The glass transition temperature (Tg) was measured according to JIS K7121.
Using a differential scanning calorimeter (“DSC-50” manufactured by Shimadzu Corporation), the temperature of the sample was once raised to 230 ° C. and cooled to room temperature, and then increased again from room temperature to 230 ° C. at a rate of 10 ° C./min. The DSC curve was measured under the condition of raising the temperature at. The intermediate point obtained from the obtained DSC curve was defined as the glass transition temperature (Tg).

(Viscosity average molecular weight (Mv))
The viscosity average molecular weight (Mv) of the polycarbonate resin was measured using an Ubbelohde viscometer.
The specific viscosity η _sp of a solution obtained by dissolving 0.5 g of polycarbonate resin in 100 ml of methylene chloride was measured at 20 ° C., and the intrinsic viscosity [η] and viscosity of the methylene chloride solution at 20 ° C. were measured as values satisfying the following Schnell equation: Average molecular weight (Mv) was calculated.
η _sp /c=[η]+0.45×[η] ² c,
^{[Η] = 1.23 × 10 -} 4 Mv 0.83
(In the above formula, [η] is the intrinsic viscosity. C is a constant, and c = 0.5 under the above conditions.)

⁽¹ H-NMR and ¹³ C-NMR analysis)
The composition of the resin was analyzed by ¹ H-NMR or ¹³ C-NMR.
As the apparatus, a nuclear magnetic resonance apparatus (ULTRA SHIELD 400 PLUS manufactured by Bruker) was used.
The measurement was carried out using 10 mL of a sample to be analyzed using 1 mL of deuterated chloroform as a deuterated solvent at room temperature with the following number of integrations.
Number of integrations in the case of ¹ H-NMR: 64 times.
Number of integrations in the case of ¹³ C-NMR: 5000 times.
Moreover, the area (X) of the region of 0.6 to 0.95 ppm and the area (Y) of the region of 0.6 to 1.35 ppm when the reference substance (TMS) is set to 0 ppm from the ¹ H-NMR spectrum. Then, the syndiotacticity (rr) in triplet display was calculated by the formula: (X / Y) × 100.

(Melt Mass Flow Rate (MFR))
The melt mass flow rate (MFR) was measured under the conditions of 230 ° C., 3.8 kg load, and 10 minutes in accordance with JIS K7210.

(Refractive index (n _23D ))
A test film having a size of 3 cm × 3 cm and a thickness of 3 mm was produced by press molding. With respect to this test film, the refractive index (n _23D ) is measured at a measurement wavelength of 587.6 nm (d-line) in an environment of 50% relative humidity (RH) and 23 ° C. using “KPR-20” manufactured by Kalnew Optical Co., Ltd. It was measured.

(Production Example 1) Production of first methacrylic resin (A-1) Same as copolymer (A-1) described in [Example] of Patent Document 6 listed in "Background Art" Thus, a first methacrylic resin (A-1) was obtained.
^{As a result of 13} C-NMR analysis, the composition of the obtained resin was as follows: the structural unit derived from methyl methacrylate was 26% by mass, the structural unit derived from maleic anhydride having a cyclic structure was 18% by mass, and The derived structural unit was 56% by mass.
The obtained resin was Mw: 169000, Mw / Mn: 2.47, Tg: 137 degreeC.

(Production Example 2) Production of second methacrylic resin (C-1) The inside of an autoclave equipped with a stirrer and a sampling tube was replaced with nitrogen. To this, 99 parts by mass of purified methyl methacrylate, 1 part by mass of methyl acrylate, 2,2′-azobis (2-methylpropionitrile (hydrogen abstraction ability: 1%, 1 hour half-life temperature: 83 ° C.) 0.0052 parts by mass and 0.25 parts by mass of n-octyl mercaptan were added and stirred to obtain a raw material liquid, and nitrogen was fed into the raw material liquid to remove dissolved oxygen in the raw material liquid.
The raw material liquid was put to 2/3 of the capacity in a tank reactor connected to the autoclave by piping. The temperature was maintained at 140 ° C., and the polymerization reaction was first started in a batch mode.

When the polymerization conversion reached 55% by mass, the polymerization reaction was switched to a continuous flow type polymerization reaction. The raw material liquid was supplied from the autoclave to the tank reactor at a flow rate at which the average residence time was 150 minutes, and the reaction liquid was withdrawn from the tank reactor at a flow rate corresponding to the supply flow rate of the raw material liquid. During the continuous flow polymerization reaction, the temperature of the reaction solution in the reactor was maintained at 140 ° C. After switching to the continuous flow polymerization reaction, the polymerization conversion in a steady state was 55% by mass.

The reaction liquid withdrawn from the tank reactor in a steady state was heated by supplying it to a multi-tube heat exchanger having an internal temperature of 230 ° C. at a flow rate with an average residence time of 2 minutes. Next, the heated reaction liquid was introduced into a flash evaporator, and volatile components mainly composed of unreacted monomers were removed to obtain a molten resin.

The molten resin from which volatile components have been removed is supplied to a twin-screw extruder having an internal temperature of 260 ° C., discharged into a strand, and cut with a pelletizer to obtain a pellet-like second methacrylic resin (C-1). It was. The obtained resin had a content of structural units derived from methyl methacrylate of 99.2% by mass. The resulting resin, Mw: 89000, Mw / Mn : 1.87, syndiotacticity (rr): 52%, Tg : 119 ℃, MFR: 2.3g / 10 _min, n 23D: In 1.491 there were.

Production Example 3 Production of Block Copolymer (B-1) In this production example, the raw material compound was dried and purified by a conventional method and degassed with nitrogen. Moreover, the transfer and supply of the compounds were performed under a nitrogen atmosphere.

  In a three-necked flask purged with nitrogen and purged with nitrogen, 735 g of dry toluene, 0.4 g of hexamethyltriethylenetetramine, and isobutylbis (2,6-di-t-butyl-4-methylphenoxy) were added at room temperature. 39.4 g of a toluene solution consisting of 20 mmol of aluminum was added. To this was added 1.17 mmol sec-butyllithium. Further, 39.0 g of methyl methacrylate was added thereto and reacted at room temperature for 1 hour to obtain a methyl methacrylate polymer (b1-1). Mw of the methyl methacrylate polymer (b1-1) contained in the reaction solution was 45800.

Next, the reaction solution was brought to −25 ° C., and a mixed solution of 29.0 g of n-butyl acrylate and 10.0 g of benzyl acrylate was added dropwise over 0.5 hour to prepare a methyl methacrylate polymer (b1-1). The polymerization reaction was continued from the end.
As a result, a block copolymer (diblock consisting of a methyl methacrylate polymer block (b1-1) and an acrylate polymer block (b2-1) composed of n-butyl acrylate and benzyl acrylate ( B-1) was obtained.

The block copolymer (B-1) in the reaction solution was Mw: 92000 and Mw / Mn: 1.06. Since Mw of the methyl methacrylate polymer (b1-1) was 45800, the Mw of the acrylate polymer (b2-1) was determined to be 46200.
The proportion of benzyl acrylate units in the acrylate polymer (b2-1) is 25.6% by mass, and the proportion of benzyl acrylate units in the block copolymer (B-1) is 12.8% by mass. Met.

  Subsequently, 4 g of methanol was added to the reaction solution to stop the polymerization. Thereafter, the reaction solution was poured into a large amount of methanol to precipitate the diblock copolymer (B-1). The resulting precipitate was filtered off and dried at 80 ° C. and 1 torr (about 133 Pa) for 12 hours.

_{N 23D} of the obtained diblock copolymer (B-1) was 1.490. Moreover, mass ratio of the methacrylic acid ester polymer block (b1-1) and the acrylate polymer block (b2-1) was 50:50.

Table 1 shows the composition and physical properties of the block copolymer (B) obtained in Production Example 3.
Each abbreviation in the table indicates the following components.
MMA: methyl methacrylate,
BA: n-butyl acrylate,
BzA: benzyl acrylate.

(Production Example 4) Production of crosslinked rubber particles (G-1) A reaction vessel (100 L) equipped with a condenser, a thermometer and a stirrer and subjected to glass lining was charged with 48 kg of ion-exchanged water, and then sodium stearate 416 g, 128 g of sodium lauryl sarcosinate and 16 g of sodium carbonate were added and dissolved. Next, 11.2 kg of methyl methacrylate and 110 g of allyl methacrylate were added and the temperature was raised to 70 ° C. while stirring, and then 560 g of 2% aqueous potassium persulfate solution was added to initiate polymerization. An emulsion was obtained by maintaining at 70 ° C. for 30 minutes after the completion of the polymerization peak.

After further adding 720 g of 2% sodium persulfate aqueous solution to the obtained emulsion, a monomer mixture consisting of 12.4 kg of butyl acrylate, 1.76 kg of styrene and 280 g of allyl methacrylate was dropped over 60 minutes, and then Graft polymerization was carried out by continuing stirring for 60 minutes.

Add 320 g of 2% aqueous potassium persulfate solution to the emulsion after graft polymerization, and then add a monomer mixture consisting of 6.2 kg of methyl methacrylate, 0.2 kg of methyl acrylate and 200 g of n-octyl mercaptan over 30 minutes. did. Thereafter, stirring was continued for 60 minutes to complete the polymerization, followed by cooling to obtain a polymer emulsion.
The obtained emulsion (hereinafter referred to as “emulsion containing multilayer polymer particles (P)”) contains 40% by mass of multilayer polymer particles (P) (three-stage polymer) having an average particle size of 0.23 μm. It was a thing.

Separately, 48 kg of ion-exchanged water was added to the same reaction tank as described above, and then 252 g of a surfactant (“Perex SS-H” manufactured by Kao Corporation) was added and stirred to dissolve. After raising the temperature to 70 ° C., 160 g of a 2% potassium persulfate aqueous solution was added. Subsequently, polymerization was started by adding a mixture of 3.04 kg of methyl methacrylate, 0.16 kg of methyl acrylate and 15.2 g of n-octyl mercaptan all at once.

Stirring was continued for 30 minutes after the end of heat generation due to polymerization, and then 160 g of 2% aqueous potassium persulfate solution was added, and then a mixture of 27.4 kg of methyl methacrylate, 1.44 kg of methyl acrylate and 98 g of n-octyl mercaptan was added. The polymerization was carried out by continuously dropping over 2 hours. After completion of dropping, the mixture was allowed to stand for 60 minutes and then cooled to obtain a polymer emulsion containing 40% by mass of (meth) acrylate polymer particles (Q) having an average particle size of 0.12 μm.
The intrinsic viscosity of the (meth) acrylate polymer particles (Q) in the obtained emulsion (hereinafter referred to as “emulsion containing (meth) acrylate polymer particles (Q)”) is 0.44 g / dl.

The emulsion containing the multilayer structure polymer particles (P) and the emulsion containing the (meth) acrylate polymer particles (Q) are mixed so that the mass ratio of (P) :( Q) is 2: 1. did. The obtained mixed emulsion was frozen at −20 ° C. for 2 hours. The frozen mixed emulsion was poured into hot water of 80 ° C. twice that amount and dissolved to form a slurry. This was kept at 80 ° C. for 20 minutes, dehydrated, and dried at 70 ° C. to obtain powdered crosslinked rubber particles (G-1).

(Polycarbonate resin (PC))
The following polycarbonate resin (PC) was prepared.
Polycarbonate resin (PC-1): “AL071” manufactured by Mitsubishi Engineering Plastics, Mv = 5200.

(UV absorber)
The following ultraviolet absorbers were prepared.
UVA-1: 2,4,6-tris (2-hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine (manufactured by ADEKA; LA-F70)

(Example 1) Production of methacrylic resin composition (MR1-1) 80 parts by mass of methacrylic resin (A-1) and 20 parts by mass of block copolymer (B-1) were mixed. A methacrylic resin composition (MR1-1) was obtained by kneading and extruding the obtained mixed resin at 250 ° C. using a twin-screw extruder (trade name: KZW20TW-45MG-NH-600, manufactured by Technobel). Got.
Table 2 shows the composition of the methacrylic resin composition (MR1-1).

(Examples 2 and 3)
A methacrylic resin composition (MR1-2) and (MR1-3) were produced in the same manner as in Example 1 except that the compositions shown in Table 2 were used.

(Comparative Examples 1-3)
Methacrylic resin compositions (MR2-1) to (MR2-3) were produced in the same manner as in Example 1 except that the compositions shown in Table 2 were used.

(Evaluation of methacrylic resin composition)
The Mw, molecular weight distribution (Mw / Mn), and Tg of the methacrylic resin compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were as shown in Table 2.

(Evaluation of film 1)
In Examples 1-3 and Comparative Examples 1-3, a film (unstretched film) was obtained using the obtained methacrylic resin composition, and the following evaluation was performed. These evaluation results are shown together in Table 2.

<Total light transmittance of unstretched film>
The obtained methacrylic resin composition was hot-press molded to obtain a 120 mm × 50 mm × 1.0 mm film (unstretched film). The total light transmittance of an unstretched film (1.0 mm thickness) was measured using a haze meter (manufactured by Murakami Color Research Laboratory, HM-150) according to JIS K7361-1.

<Haze of unstretched film (23 ° C.)>
The obtained methacrylic resin composition was hot-press molded to obtain a 120 mm × 50 mm × 1.0 mm film (unstretched film). Based on JISK7136, the haze of the unstretched film (1.0 mm thickness) was measured at 23 ° C. using a haze meter (manufactured by Murakami Color Research Laboratory, HM-150).

<3-point bending evaluation of unstretched film>
The obtained methacrylic resin composition was dried at 80 ° C. for 12 hours. Using a 20 mmφ single screw extruder (OCS), at a resin temperature of 260 ° C., the methacrylic resin composition is extruded from a 150 mm wide T-die, taken out with a cooling roll, and a film having a width of 100 mm and a thickness of 1 mm. (Unstretched film) was obtained. The obtained film was cut out to 50 mm × 20 mm. Using this as a test film, a three-point bending test at 23 ° C. was performed using an autograph (manufactured by Shimadzu Corporation).
The state of measurement is schematically shown in FIG.
The test film was stretched over two lower fulcrums spaced apart by 30 mm, and the upper fulcrum was pushed from above at the center position of the two lower fulcrums of this film. said. The presence or absence of breakage of the test film when the upper fulcrum was pushed 10 mm from the upper surface of the test film was visually confirmed. Evaluation was performed according to the following criteria.
Good: No breakage,
Bad: There is a break.

<Evaluation results>
As shown in Table 2, Example 1 using the first methacrylic resin (A) and the block copolymer (B), and the first methacrylic resin (A) and the block copolymer (B ) And the second methacrylic resin (C) in Examples 2 and 3, a methacrylic resin composition having a high glass transition temperature (Tg) and good heat resistance and excellent moldability is obtained. It was. In these examples, an unstretched film having good total light transmittance and haze and excellent bending strength was obtained.
On the other hand, in Comparative Example 1 using only the first methacrylic resin (A) without using the block copolymer (B), the glass transition temperature (Tg) was high and the heat resistance was good. The obtained unstretched film had poor bending strength.
In Comparative Example 2 using only the second methacrylic resin (C) without using the block copolymer (B), the glass transition temperature (Tg) is low and heat resistance is poor as compared with Examples 1 to 3. It was enough. Moreover, the unstretched film obtained in Comparative Example 2 had poor bending strength.
In Comparative Example 3 using the first methacrylic resin (A) and the crosslinked rubber particles (G) without using the block copolymer (B), the glass transition temperature (Tg) was high and the heat resistance was good. However, the obtained unstretched film had poor bending strength. Moreover, the unstretched film obtained in Comparative Example 3 using the crosslinked rubber particles (G) also had poor total light transmittance and haze.

(Evaluation of film 2)
For the methacrylic resin composition (MR1-2) obtained in Example 2 and the methacrylic resin composition (MR2-1) obtained in Comparative Example 1, film evaluation 2 was performed.
The obtained methacrylic resin composition was dried at 80 ° C. for 12 hours. Next, using a 20 mmφ single screw extruder (OCS), the methacrylic resin composition was extruded from a 150 mm wide T-die at a resin temperature of 260 ° C., and was taken out by a roll having a surface temperature of 100 ° C. An unstretched film having a thickness of 160 μm was obtained.

<Surface smoothness of unstretched film>
The surface of the obtained unstretched film was visually observed, and the surface smoothness was evaluated according to the following criteria.
Good: The surface is smooth,
Defect: There are irregularities on the surface.

<Extension process>
A section having a size of 100 mm × 100 mm was cut out from the unstretched film. This section was set in a pantograph type biaxial stretching tester (manufactured by Toyo Seiki Co., Ltd.). First, the film was stretched in the machine direction under the conditions of stretching temperature: glass transition temperature (Tg) + 20 ° C., stretching speed: 1000% / min, and stretching ratio: 2 times. Next, the film was stretched in the transverse direction under the conditions of stretching temperature: glass transition temperature (Tg) + 20 ° C., stretching speed: 1000% / min, and stretching ratio: 2 times. Thus, the film biaxially stretched successively in an area ratio of 4 times was gradually cooled to obtain a biaxially stretched film having a thickness of 40 μm.

<Extensible>
When 10 pieces are sequentially biaxially stretched and 5 or more films without cracks and cracks can be obtained, “good”, when only 4 or less films without cracks and cracks can be obtained Was evaluated as “bad”.

<Total light transmittance of stretched film>
Based on JIS K7361-1, the total light transmittance of the stretched film was measured using a haze meter (manufactured by Murakami Color Research Laboratory, HM-150).

<Haze of stretched film (23 ° C.)>
Based on JISK7136, the haze of the stretched film was measured at 23 ° C. using a haze meter (manufactured by Murakami Color Research Laboratory, HM-150).

<Evaluation results>
Table 3 shows the evaluation results of Evaluation 2 of the film of Example 2. Table 3 also shows the composition.
In Example 2 using the first methacrylic resin (A), the block copolymer (B), and the second methacrylic resin (C), biaxial stretching can be carried out satisfactorily, A biaxially stretched film having good transmittance and haze was obtained.
On the other hand, in Comparative Example 1 using only the first methacrylic resin (A) without using the block copolymer (B), the obtained methacrylic resin is fragile and easily cracked. The biaxial stretching could not be carried out satisfactorily.

The methacrylic resin composition of the present invention can be used for various molded articles and resin films. The methacrylic resin composition of the present invention can be suitably used for various optical films such as a polarizer protective film and a retardation film.

Claims (13)

Selected from the group consisting of a structural unit (M) derived from methyl methacrylate and a lactone ring unit, maleic anhydride unit, glutaric anhydride unit, glutarimide unit, N-substituted maleimide unit, and tetrahydropyran ring structural unit. A first methacrylic resin (A) comprising at least one ring structural unit (R) having a ring structure in the main chain;
10 to 80% by mass of a methacrylic acid ester polymer block (b1) containing a structural unit derived from a methacrylic acid ester and 90 to 20% by mass of an acrylate polymer block (b2) containing a structural unit derived from an acrylate ester A block copolymer (B) containing
For the total amount of 100 parts by mass of the first methacrylic resin (A) and the block copolymer (B),
The amount of the first methacrylic resin (A) is 10 to 99 parts by mass,
The amount of the block copolymer (B) is 90 to 1 part by mass,
Methacrylic resin composition. 70% by mass or more of a structural unit (M) derived from methyl methacrylate, and a lactone ring unit, a maleic anhydride unit, a glutaric anhydride unit, a glutarimide unit, an N-substituted maleimide unit, and a tetrahydropyran ring structure A second methacrylic resin (C) which is selected from the group consisting of units and does not contain at least one ring structural unit (R) having a ring structure in the main chain;
For a total amount of 100 parts by mass of the first methacrylic resin (A), the block copolymer (B), and the second methacrylic resin (C),
The amount of the second methacrylic resin (C) is more than 0 parts by mass and 70 parts by mass or less.
The methacrylic resin composition according to claim 1. For the total amount of 100 parts by mass of the first methacrylic resin (A) and the block copolymer (B),
The amount of the first methacrylic resin (A) is 75 to 95 parts by mass,
The amount of the block copolymer (B) is 25 to 5 parts by mass.
The methacrylic resin composition according to claim 1. For a total amount of 100 parts by mass of the first methacrylic resin (A), the block copolymer (B), and the second methacrylic resin (C),
The total amount of the first methacrylic resin (A) and the second methacrylic resin (C) is 75 to 95 parts by mass,
The amount of the block copolymer (B) is 25 to 5 parts by mass.
The methacrylic resin composition according to claim 2. The acrylic ester polymer block (b2)
50 to 90% by mass of non-aromatic structural unit derived from an acrylate ester having no aromatic ring,
Containing 50 to 10% by mass of an aromatic structural unit derived from a (meth) acrylic acid ester having an aromatic ring,
The methacrylic resin composition according to any one of claims 1 to 4. Further comprising a UV absorber,
The methacrylic resin composition according to any one of claims 1 to 5. For the total amount of 100 parts by mass of the first methacrylic resin (A) and the block copolymer (B),
Further comprising 1 to 10 parts by weight of polycarbonate resin (PC),
The methacrylic resin composition according to claim 1. For a total amount of 100 parts by mass of the first methacrylic resin (A), the block copolymer (B), and the second methacrylic resin (C),
Further comprising 1 to 10 parts by weight of polycarbonate resin (PC),
The methacrylic resin composition according to claim 2.   The molded object which consists of a methacrylic-type resin composition in any one of Claims 1-8. A resin film comprising the methacrylic resin composition according to claim 1.   The resin film according to claim 10, which is a stretched film.   A polarizer protective film comprising the resin film according to claim 10.   A retardation film comprising the resin film according to claim 10.

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