WO2018021449A1

WO2018021449A1 - Methacrylate resin composition, method for producing same, molded body, film, laminated film, and laminated molded body

Info

Publication number: WO2018021449A1
Application number: PCT/JP2017/027148
Authority: WO
Inventors: 直人福原; 展史川北; 淳裕中原; 達阿部
Original assignee: 株式会社クラレ
Priority date: 2016-07-29
Filing date: 2017-07-27
Publication date: 2018-02-01
Also published as: JP7045994B2; KR20190035779A; TWI767924B; TW201815945A; CN109563328A; JPWO2018021449A1; KR102346225B1

Abstract

The present invention provides a methacrylate resin composition from which a molded body having excellent high-temperature formability and high dimensional stability against heat can be obtained. This methacrylate resin composition is made of a methacrylate resin (M1) having an α relaxation temperature T_α1 of at least 137^oC at the time of dynamic viscoelastic measurement in a tensile mode at 1 Hz, and a methacrylate resin (M2) having an α relaxation temperature T_α2 of 132^oC or lower at the time of dynamic viscoelastic measurement in a tensile mode at 1 Hz. When the melt viscosities of the methacrylate resin (M1) and the methacrylate resin (M2) at a temperature of 260^oC and a shear rate of 122 sec^-1 are η₁ and η₂, respectively, η₁ is greater than η₂, and the mass ratio of the methacrylate resin (M1)/the methacrylate (M2) ranges from 2/98 to 30/70.

Description

Methacrylic resin composition and production method thereof, molded product, film, laminated film, laminated molded product

The present invention relates to a methacrylic resin composition and a production method thereof, a molded body, a film, a laminated film, and a laminated molded body.

Methacrylic resin has high transparency and is suitable as a material for optical members, lighting members, signboard members, decorative members, and the like. However, a general-purpose methacrylic resin has a low glass transition temperature (Tg) of about 110 ° C. and is not very good in heat resistance, so that the dimensional stability of the molded product against heat is not good. As a methacrylic resin having a high Tg, a methacrylic resin having a high syndiotacticity (rr) is known. An anionic polymerization method is mentioned as a manufacturing method of a methacryl resin with high syndiotacticity (rr) (refer patent documents 1 and 2). However, a methacrylic resin having a high syndiotacticity (rr) obtained by this method has poor moldability, and the resulting molded product tends to have poor surface smoothness. Although the moldability can be improved by lowering the molecular weight, the mechanical strength of the resulting molded product tends to decrease. Therefore, the present condition is that the molded object which consists of a methacryl resin with high syndiotacticity (rr) is not put into practical use.

In Patent Document 3, a methacrylic resin [1] having a triplet display syndiotacticity (rr) of 65% or more, and a triplet display syndiotacticity (rr) of 45 to 58%. A methacrylic resin composition containing methacrylic resin [2] in a mass ratio of 40/60 to 70/30 of methacrylic resin [1] / methacrylic resin [2] is disclosed (claim 1). By blending the methacrylic resin [1] having a high syndiotacticity (rr) and the atactic methacrylic resin [2] in the above mass ratio, it is possible to achieve both improved heat resistance and good moldability.

Japanese Patent Laid-Open No. 3-26312 Japanese Patent Laid-Open No. 2002-327012 International Publication No. 2014/185509

As described above, generally in methacrylic resins, heat resistance (dimensional stability against heat) and moldability are contradictory properties, and it is difficult to achieve both. In recent years, there has been an increasing demand for molded articles such as complicated shapes and high dimensional stability against heat. Therefore, it has been demanded that a molded article having good moldability at high temperature and having high dimensional stability against heat can be molded.

The present invention has been made in view of the above problems, and provides a methacrylic resin composition capable of obtaining a molded article having good high-temperature moldability and high dimensional stability against heat, and a method for producing the same. The purpose is to provide.

The present invention provides the following methacrylic resin composition and method for producing the same, molded body, film, laminated film, and laminated molded body.
[1] A methacrylic resin (M1) having an α relaxation temperature T _α1 of 137 ° C. or higher when measured in a dynamic mode at 1 Hz in a tensile mode,
A tensile mode, a methacrylic resin composition with a methacrylic resin (M2) having an α relaxation temperature _Tα2 of 132 ° C. or lower when dynamic viscoelasticity is measured at 1 Hz,
When the melt viscosity of the methacrylic resin (M1) and the methacrylic resin (M2) at 260 ° C. and a shear rate of 122 sec ⁻¹ is η ₁ and η ₂ , respectively, η ₁ > η ₂
A methacrylic resin composition having a methacrylic resin (M1) / methacrylic resin (M2) mass ratio of 2/98 to 29/71.

[2] The methacrylic resin composition according to [1], wherein the molecular weight distribution (Mw / Mn) of the methacrylic resin (M1) is 1.0 to 1.4.
[3] The methacrylic resin composition according to [1] or [2], wherein the methacrylic resin (M1) has a weight average molecular weight (Mw) of 40,000 to 200,000.
[4] The methacrylic resin composition according to any one of [1] to [3], wherein the content of the methyl methacrylate monomer unit in the methacrylic resin (M2) is 99% by mass or more.
[5] The methacrylic resin composition according to any one of [1] to [4], further comprising a polycarbonate resin (PC) and / or a phenoxy resin (PR).
[6] The methacrylic resin composition according to any one of [1] to [5], further comprising a crosslinked rubber (CR) and / or a block copolymer (BP).
[7] The methacrylic resin composition according to any one of [1] to [6], further comprising an ultraviolet absorber (LA).

[8] When the melt viscosity of the methacrylic resin (M1) and the methacrylic resin (M2) at 260 ° C. and a shear rate of 122 sec ⁻¹ is η ₁ and η ₂ , η ₁ > η ₂
A methacrylic resin (M1) having an α relaxation temperature T _α1 of 137 ° C. or higher when measured in a tensile mode and dynamic viscoelasticity at 1 Hz;
A methacrylic resin (M2) having an α relaxation temperature T _α2 of 132 ° C. or lower when a dynamic viscoelasticity measurement is performed at a tensile mode of 1 Hz.
A method for producing a methacrylic resin composition, comprising melt-kneading a methacrylic resin (M1) / methacrylic resin (M2) in a mass ratio of 2/98 to 29/71.

[9] A molded article comprising the methacrylic resin composition according to any one of [1] to [7].
[10] A film comprising the methacrylic resin composition according to any one of [1] to [7].
[11] The film according to [10], which is a stretched film.
[12] A laminated film having a layer comprising the film of [10] or [11].
[13] The laminated film according to [12], further comprising a layer made of a metal and / or a metal oxide.
[14] The laminated film of [12] or [13] further having an adhesive layer.
[15] A laminated molded body in which the laminated film of any one of [12] to [14] is laminated on a substrate.

In the present specification, “α relaxation temperature (T _α )”, “melt viscosity (η)”, “weight average molecular weight (Mw)”, and “molecular weight distribution (Mw / Mn)” are the items in [Example]. It shall be measured by the method described in 1.

According to the present invention, it is possible to provide a methacrylic resin composition capable of obtaining a molded article having good high temperature moldability and high dimensional stability against heat, and a method for producing the same.

"Methacrylic resin composition"
The methacrylic resin composition of the present invention is composed of a methacrylic resin (M1) having an α relaxation temperature T _α1 of 137 ° C. or higher when measured in a dynamic mode at a tensile mode and 1 Hz, and a dynamic viscoelasticity measurement at a tensile mode and 1 Hz. And a methacrylic resin (M2) having an α relaxation temperature T _α2 of 132 ° C. or lower.

In the present specification, the “α relaxation temperature (T _α )” is the peak top temperature of relaxation (α relaxation) due to segment motion of the polymer main chain. The α relaxation temperature (T _α ) can be measured by the method described in the [Example] section.
In general, there is a correlation between the glass transition temperature (Tg) obtained from the DSC curve and the α relaxation temperature (T _α ), but in the present invention, instead of the α relaxation temperature (T _α ). Tg is not used as an index.

(Methacrylic resin (M1))
The methacrylic resin (M1) is not particularly limited as long as the α relaxation temperature T _α1 is 137 ° C. or higher when dynamic viscoelasticity measurement is performed in a tensile mode and a sine wave of 1 Hz. One or more methacrylic resins (M1) can be used. The methacrylic resin (M1) includes one or more methacrylic acid ester monomer units such as a methyl methacrylate (MMA) monomer unit. Examples of methacrylic acid esters include MMA, ethyl methacrylate and butyl methacrylate alkyl esters; phenyl methacrylate and other methacrylic acid aryl esters; methacrylic acid cyclohexyl and methacrylic acid cycloalkyl esters such as norbornenyl Is mentioned. Among these, methacrylic acid alkyl ester is preferable, and MMA is most preferable.

The content of the methacrylic acid ester monomer unit in the methacrylic resin (M1) is preferably 20% by mass or more, more preferably 50% by mass or more. As the methacrylic resin (M1), a methacrylic copolymer (A1) containing a MMA monomer unit and a monomer unit that increases the α relaxation temperature (T _α ), a MMA monomer unit and a ring structure as a main chain And a methacrylic resin (A3) having a high syndiotacticity (rr) in triplet display, and the like.

<Methacrylic copolymer (A1)>
Monomer units that increase the α relaxation temperature (T _α ) in the methacrylic copolymer (A1) include 2-isobornyl methacrylate and 8-tricyclo [5.2.1.0 ^2,6 ] decanyl methacrylate. Methacrylic acid cycloalkyl esters such as 2-norbornyl methacrylate and 2-adamantyl methacrylate; (meth) acrylic acids such as acrylic acid and methacrylic acid; acrylamide, methacrylamide, N-methylmethacrylamide, and N, N- Examples include structural units derived from monomers such as (meth) acrylamides such as dimethylmethacrylamide.

<Methacrylic copolymer (A2)>
As the structural unit having a ring structure in the main chain in the methacrylic copolymer (A2), as the ring structure, a lactone ring unit, a maleic anhydride unit, a glutaric anhydride unit, a glutarimide unit, an N-substituted maleimide unit, Or the structural unit containing a tetrahydropyran ring unit is preferable. As a method for producing the methacrylic copolymer (A2), a method of copolymerizing a cyclic monomer having a polymerizable unsaturated carbon-carbon double bond such as maleic anhydride and N-substituted maleimide with MMA or the like; And a method of intramolecular cyclization of a part of the molecular chain of the methacrylic resin obtained by the above.

The content of the MMA monomer unit in the methacrylic copolymer (A2) is preferably 20 to 99% by mass, more preferably 30 to 95% by mass, and particularly preferably 40 to 90% by mass. The content of structural units in the chain is preferably 1 to 80% by mass, more preferably 5 to 70% by mass, and particularly preferably 10 to 60% by mass. The content of the MMA monomer unit in the methacrylic copolymer (A2) is the MMA monomer unit converted into a structural unit having a ring structure in the main chain by intramolecular cyclization. Not included.

As structural units having a ring structure in the main chain, structural units containing> CH—O—C (═O) — group in the ring structure, and —C (═O) —O—C (═O) — groups are cyclic A structural unit containing a structure, a structural unit containing a —C (═O) —N—C (═O) — group in the ring structure, or a structural unit containing a> CH—O—CH <group in the ring structure is preferable.

> Structural units containing a CH—O—C (═O) — group in the ring structure include β-propiolactone diyl (also known as oxooxetanediyl) structural unit, γ-butyrolactone diyl (also known as 2-oxodihydrofurandi) Yl) structural unit, and lactone diyl structural unit such as δ-valerolactone diyl (also known as 2-oxodihydropyrandiyl) structural unit. In the formula, “> C” means that the carbon atom C has two bonds.

Examples of the δ-valerolactone diyl structural unit include structural units represented by the following formula (I).

In the formula (I), R ¹⁴ and R ¹⁵ are each independently a hydrogen atom or an organic residue having 1 to 20 carbon atoms, preferably R ¹⁴ is a hydrogen atom and R ¹⁵ is a methyl group. R ¹⁶ is —COOR, R is a hydrogen atom or an organic residue having 1 to 20 carbon atoms, preferably a methyl group. “*” Means a bond.
Examples of the organic residue include linear or branched alkyl groups, linear or branched alkylene groups, aryl groups, —OAc groups, and —CN groups. The organic residue may contain an oxygen atom. “Ac” represents an acetyl group. The carbon number of the organic residue is preferably 1 to 10, more preferably 1 to 5.
The δ-valerolactone diyl structural unit can be contained in a methacrylic resin by intramolecular cyclization of two adjacent MMA monomer units.

The structural unit containing a —C (═O) —O—C (═O) — group in the ring structure includes 2,5-dioxodihydrofurandiyl structural unit, 2,6-dioxodihydropyrandiyl structural unit, And 2,7-dioxooxepanediyl structural unit.

Examples of the 2,5-dioxodihydrofurandiyl structural unit include structural units represented by the following formula (II).

In formula (II), R ²¹ and R ²² are each independently a hydrogen atom or an organic residue having 1 to 20 carbon atoms. “*” Means a bond.
Examples of the organic residue include linear or branched alkyl groups, linear or branched alkylene groups, aryl groups, —OAc groups, and —CN groups. The organic residue may contain an oxygen atom. “Ac” represents an acetyl group. The carbon number of the organic residue is preferably 1 to 10, more preferably 1 to 5.
R ²¹ and R ²² are preferably both hydrogen atoms. In that case, styrene or the like is preferably copolymerized from the viewpoints of ease of production and adjustment of intrinsic birefringence. Specifically, a copolymer having a styrene monomer unit, a MMA monomer unit, and a maleic anhydride monomer unit described in International Publication No. 2014/021264 is exemplified.
The 2,5-dioxodihydrofurandiyl structural unit can be contained in the methacrylic resin by copolymerization using maleic anhydride or the like.

Examples of the 2,6-dioxodihydropyrandiyl structural unit include structural units represented by the following formula (III).

In the formula (III), R ³³ and R ³⁴ are each independently a hydrogen atom or an organic residue having 1 to 20 carbon atoms. “*” Means a bond.
Examples of the organic residue include linear or branched alkyl groups, linear or branched alkylene groups, aryl groups, —OAc groups, and —CN groups. The organic residue may contain an oxygen atom. “Ac” represents an acetyl group. The organic residue preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group.
The 2,6-dioxodihydropyrandiyl structural unit can be contained in the methacrylic resin by intramolecular cyclization of two adjacent MMA monomers.

2,5-dioxopyrrolidine is a structural unit containing a —C (═O) —N—C (═O) — group in a ring structure (note that another bond of N is omitted). Examples thereof include a diyl structural unit, a 2,6-dioxopiperidinediyl structural unit, and a 2,7-dioxoazepandiyl structural unit.

Examples of the 2,6-dioxopiperidinediyl structural unit include structural units represented by the following formula (IV).

In the formula (IV), R ⁴¹ and R ⁴² are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and R ⁴³ is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or an alkyl group having 3 to 12 carbon atoms. A cycloalkyl group or an aryl group having 6 to 10 carbon atoms. “*” Means a bond.
From the viewpoints of easy availability of raw materials, cost, heat resistance, etc., R ⁴¹ and R ⁴² are preferably each independently a hydrogen atom or a methyl group, and R ⁴¹ is a methyl group and R ⁴² is a hydrogen atom. Is more preferable. R ⁴³ is preferably a hydrogen atom, a methyl group, an n-butyl group, a cyclohexyl group, or a benzyl group, and more preferably a methyl group.

Examples of the 2,5-dioxopyrrolidinediyl structural unit include structural units represented by the following formula (V).

In the formula (V), R ⁵² and R ⁵³ are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alkyl group having 6 to 14 carbon atoms. R ⁵¹ is an arylalkyl group having 7 to 14 carbon atoms or an unsubstituted or substituted aryl group having 6 to 14 carbon atoms. The substituent mentioned here is a halogeno group, a hydroxyl group, a nitro group, an alkoxy group having 1 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms, or an arylalkyl group having 7 to 14 carbon atoms. “*” Means a bond. R ⁵¹ is preferably a phenyl group or a cyclohexyl group, and both R ⁵² and R ⁵³ are preferably hydrogen atoms.
The 2,5-dioxopyrrolidinediyl structural unit can be contained in the methacrylic resin by copolymerization using N-substituted maleimide or the like.

Examples of the structural unit containing a> CH—O—CH <group in the ring structure include an oxetanediyl structural unit, a tetrahydrofurandiyl structural unit, a tetrahydropyrandiyl structural unit, and an oxepandiyl structural unit. In the formula, “> C” means that the carbon atom C has two bonds.

Examples of the tetrahydropyrandiyl structural unit include a structural unit represented by the following formula (VI).

In the formula (VI), R ⁶¹ and R ⁶² are each independently a hydrogen atom, a linear or branched hydrocarbon group having 1 to 20 carbon atoms, or a hydrocarbon group having 3 to 20 carbon atoms having a ring structure. It is. “*” Means a bond. R ⁶¹ and R ⁶² are each independently a tricyclo [5.2.1.0 ^2,6 ] decanyl group, a 1,7,7-trimethylbicyclo [2.2.1] heptan-3-yl group, t A -butyl group and a 4-t-butylcyclohexanyl group are preferred.

Among the structural units having the above ring structure in the main chain, from the viewpoint of raw materials and ease of production, δ-valerolactone diyl structural unit and 2,5-dioxodihydrofurandiyl structural unit are preferable.

The molecular weight distribution (the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn), Mw / Mn) of the methacrylic copolymers (A1) and (A2) is preferably 1.2 to 5.0, more preferably Is 1.3 to 3.5. The lower the Mw / Mn, the better the impact resistance and toughness of the resulting molded article. As Mw / Mn increases, the melt fluidity of the methacrylic resin composition increases, and the surface smoothness of the resulting molded product tends to improve.
In this specification, Mw and Mn are values obtained by converting a chromatogram measured by gel permeation chromatography (GPC) into a molecular weight of standard polystyrene. Mw and Mw / Mn can be measured by the method described in the [Example] section.

The glass transition temperature (Tg) of the methacrylic copolymer (A2) is preferably 120 ° C. or higher, more preferably 123 ° C. or higher, and particularly preferably 124 ° C. or higher. The upper limit of Tg of the methacrylic copolymer (A2) is preferably 160 ° C.
In this specification, the glass transition temperature (Tg) shall be measured in accordance with JIS K7121 at a temperature of room temperature or higher. The first temperature increase (1st run) was performed at a temperature increase rate of 10 ° C./min to 230 ° C., and after cooling to room temperature, the second temperature increase from room temperature to 230 ° C. at a temperature increase rate of 10 ° C./min ( 2nd run). The midpoint glass transition temperature of 2nd run is determined as Tg.

<Methacrylic resin (A3)>
The methacrylic resin (A3) has a syndiotacticity (rr) expressed in triplets of 65% or more, preferably 70 to 90%, more preferably 72 to 85%. When the syndiotacticity (rr) is 65% or more, the α relaxation temperature (T _α ) is significantly increased, and the surface hardness of the obtained molded body is significantly increased.
The molecular weight distribution (Mw / Mn) of the methacrylic resin (A3) is preferably 1.0 to 1.8, more preferably 1.0 to 1.4, and particularly preferably 1.03 to 1.3. When a methacrylic resin (A3) having a molecular weight distribution (Mw / Mn) within such a range is used, the resulting methacrylic resin composition has excellent mechanical strength. Mw and Mw / Mn can be controlled by adjusting the type and / or amount of the polymerization initiator used during production.

The methacrylic resin (M1) may contain one or more other monomer units other than those mentioned above for the methacrylic copolymers (A1), (A2) and the methacrylic resin (A3). Good. Other monomer units include: alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate; aryl acrylates such as phenyl acrylate; Acrylic cycloalkyl esters such as cyclohexyl acrylate and norbornenyl acrylate; aromatic vinyl compounds such as styrene and α-methyl styrene; nitriles such as acrylonitrile and methacrylonitrile; -Structural units derived from vinyl monomers having only one carbon double bond.

The Mw of the methacrylic resin (M1) is preferably 40,000 to 200,000, more preferably 40,000 to 150,000, and particularly preferably 50,000 to 120,000. When Mw is 40000 or more, the mechanical strength (impact resistance, toughness, etc.) of the obtained molded product tends to be improved, and when it is 200000 or less, the fluidity of the methacrylic resin composition is improved and the moldability is improved. There is a tendency to improve.
The melt flow rate (MFR) of the methacrylic resin (M1) measured 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, particularly Preferably it is 0.5 to 20 g / 10 min, and most preferably 1.0 to 15 g / 10 min.

The methacrylic resin (M1) can be produced by a known polymerization method such as a radical polymerization method or an anionic polymerization method. In addition, a polymerization method such as a bulk polymerization method, a solution polymerization method, a suspension polymerization method, and an emulsion polymerization method is selected as the radical polymerization method, and a polymerization method such as a bulk polymerization method and a solution polymerization method is selected as the anionic polymerization method. Can do.
The radical polymerization method can be carried out without a solvent or in a solvent, and is preferably carried out without a solvent since a methacrylic resin (M1) having a low impurity concentration can be obtained. From the viewpoint of suppressing the silvering or coloring of the molded article, the polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen gas with a low dissolved oxygen content.

Examples of the polymerization initiator used in the radical polymerization method include t-hexyl peroxyisopropyl monocarbonate, t-hexyl peroxy 2-ethylhexanoate, 1,1,3,3-tetramethylbutyl peroxy 2-ethylhexa Noate, t-butyl peroxypivalate, t-hexyl peroxypivalate, t-butyl peroxyneodecanoate, t-hexyl peroxyneodecanoate, 1,1,3,3-tetra Methylbutylperoxyneodecanoate, 1,1-bis (t-hexylperoxy) cyclohexane, benzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, lauroyl peroxide, 2,2′-azobis ( 2-methylpropionitrile), 2,2'-azobis (2-methylbutyroni) Lil), and dimethyl 2,2'-azobis (2-methylpropionate), and the like. Of these, t-hexylperoxy 2-ethylhexanoate, 1,1-bis (t-hexylperoxy) cyclohexane, and dimethyl 2,2'-azobis (2-methylpropionate) are preferable. One or more polymerization initiators can be used.

The 1-hour half-life temperature of the polymerization initiator is preferably 60 to 140 ° C, more preferably 80 to 120 ° C. The polymerization initiator preferably has a hydrogen abstraction capacity of 20% or less, more preferably 10% or less, and particularly preferably 5% or less. The amount of the polymerization initiator used is preferably 0.0001 to 0.02 parts by mass, more preferably 0.001 to 0.01 based on 100 parts by mass of one or more monomers to be subjected to the polymerization reaction. Part by mass, particularly preferably 0.005 to 0.007 part by mass.

The hydrogen abstraction ability is known from the technical data of the polymerization initiator manufacturer (for example, the technical data of Nippon Oil & Fats Co., Ltd. “Hydrogen abstraction capacity and initiator efficiency of organic peroxide” (created in April 2003)). Can do. Further, it can be measured by a radical trapping method (α-methylstyrene dimer trapping method) using α-methylstyrene dimer. This measurement is generally performed as follows. First, the polymerization initiator is cleaved in the presence of α-methylstyrene dimer as a radical trapping agent to generate radical fragments. Of the generated radical fragments, radical fragments having a low hydrogen abstraction ability are added to and trapped by the double bond of α-methylstyrene dimer. On the other hand, a radical fragment having a high hydrogen abstraction capacity abstracts hydrogen from cyclohexane to generate a cyclohexyl radical, which is added to and trapped by the double bond of α-methylstyrene dimer to generate a cyclohexane capture product. Therefore, the ratio (molar fraction) of the radical fragment having a high hydrogen abstraction capacity with respect to the theoretical radical fragment generation amount, which is determined by quantifying cyclohexane or the cyclohexane-trapped product, is determined as the hydrogen abstraction capacity.

Chain transfer agents used in the radical polymerization method include n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, 1,4-butanedithiol, 1,6-hexanedithiol, ethylene glycol bisthiopropionate, butane. Diol bisthioglycolate, butanediol bisthiopropionate, hexanediol bisthioglycolate, hexanediol bisthiopropionate, trimethylolpropane tris- (β-thiopropionate), and pentaerythritol tetrakisthiopropioate Examples include alkyl mercaptans such as nates. Of these, monofunctional alkyl mercaptans such as n-octyl mercaptan and n-dodecyl mercaptan are preferable. One or more chain transfer agents can be used.

From the viewpoint of the moldability of the resin and the mechanical strength of the molded body, the amount of the chain transfer agent used is preferably 0.01 to 1 mass with respect to 100 mass parts of one or more monomers used for the polymerization reaction. Parts, more preferably 0.05 to 0.8 parts by mass, particularly preferably 0.1 to 0.6 parts by mass, and most preferably 0.10 to 0.5 parts by mass. The amount of the chain transfer agent used is preferably 2500 to 10,000 parts by mass, more preferably 3000 to 9000 parts by mass, and particularly preferably 3500 to 6000 parts by mass with respect to 100 parts by mass of the polymerization initiator.

As the solvent used in the radical polymerization method, aromatic hydrocarbons such as benzene, toluene, and ethylbenzene are preferable. One or more solvents can be used. The amount of the solvent used is preferably 100 parts by mass or less, more preferably 90 parts by mass or less, with respect to 100 parts by mass of the polymerization reaction raw material from the viewpoint of the viscosity of the reaction solution and productivity.

The polymerization reaction temperature is preferably 100 to 200 ° C, more preferably 110 to 180 ° C. When the polymerization temperature is 100 ° C. or higher, productivity tends to be improved by improving the polymerization rate and lowering the viscosity of the polymerization solution. When the polymerization temperature is 200 ° C. or less, the control of the polymerization rate is facilitated, the generation of by-products is further suppressed, and the coloring of the resin can be suppressed. From the viewpoint of production efficiency, the polymerization reaction time is preferably 0.5 to 4 hours, more preferably 1.5 to 3.5 hours, and particularly preferably 1.5 to 3 hours. The polymerization reaction time in the case of a continuous flow reactor is an average residence time in the reactor.

The polymerization conversion rate in the radical polymerization method is preferably 20 to 80% by mass, more preferably 30 to 70% by mass, and particularly preferably 35 to 65% by mass. When the polymerization conversion rate is 20% by mass or more, the remaining unreacted monomer can be easily removed, and the appearance of the obtained molded product tends to be good. When the polymerization conversion rate is 70% by mass or less, the viscosity of the polymerization solution tends to be low and the productivity tends to be improved.

The reaction apparatus may be either a batch reaction apparatus or a continuous flow reaction apparatus, and a continuous flow reaction apparatus is preferable from the viewpoint of productivity. In a continuous flow reaction, a polymerization reaction raw material (mixed solution containing one or more monomers, a polymerization initiator, a chain transfer agent, etc.) is prepared in an inert atmosphere such as nitrogen, and this is fixed in a reactor. Supply at a flow rate, and extract the liquid in the reactor at a flow rate corresponding to the supply rate. Examples of the reactor include a tubular reactor that can be in a state close to plug flow or a tank reactor that can be in a state close to complete mixing. The number of reactors may be one or two or more, and at least one reactor preferably employs a continuous flow tank reactor. The amount of liquid in the tank reactor during the polymerization reaction is preferably 1/4 to 3/4, more preferably 1/3 to 2/3 with respect to the volume of the tank reactor. The reactor is usually equipped with a stirring device. Examples of the stirring device include a static stirring device and a dynamic stirring device. Examples of the dynamic stirrer include a Max blend stirrer, a stirrer having a grid-like blade rotating around a vertical rotation shaft arranged in the center, a propeller stirrer, and a screw stirrer. Among these, a max blend type stirring device is preferable from the viewpoint of uniform mixing.

After completion of polymerization, volatile components such as unreacted monomers are removed as necessary. As a removal method, a heat devolatilization method is preferable. Examples of the devolatilization method include an equilibrium flash method and an adiabatic flash method. The devolatilization temperature by the adiabatic flash method is preferably 200 to 280 ° C, more preferably 220 to 260 ° C. The heating time of the resin in the adiabatic flash method is preferably 0.3 to 5 minutes, more preferably 0.4 to 3 minutes, and particularly preferably 0.5 to 2 minutes. When devolatilization is performed within such a temperature range and heating time, a methacrylic resin (M1) with little coloring is easily obtained. The removed unreacted monomer can be recovered and used again for the polymerization reaction. The yellow index of the recovered monomer may be high due to heat applied during the recovery operation. The recovered monomer is preferably purified by a known method to reduce the yellow index.

As a method for controlling the molecular weight distribution (Mw / Mn), a controlled polymerization method is exemplified, and a living radical polymerization method and a living anion polymerization are preferable. Living radical polymerization methods include atom transfer radical polymerization (ATRP), reversible addition fragmentation chain transfer polymerization (RAFT), nitroxide mediated polymerization (NMP), boron mediated polymerization, and catalyst transfer polymerization (CCT). Is mentioned. (Living) Anionic polymerization is a method in which an organic alkali metal compound is used as a polymerization initiator in the presence of a mineral salt such as an alkali metal or alkaline earth metal salt (see Japanese Patent Publication No. 7-25859). ), Anionic polymerization using an organic alkali metal compound as a polymerization initiator in the presence of an organic aluminum compound (see JP-A-11-335432), and anionic polymerization using an organic rare earth metal complex as a polymerization initiator (special feature). No. 6-93060) and the like.

The polymerization initiator used in the anionic polymerization method is preferably alkyllithium such as n-butyllithium, sec-butyllithium, isobutyllithium, and tert-butyllithium. From the viewpoint of productivity, it is preferable to coexist an organoaluminum compound.
As the organoaluminum compound, a compound represented by the formula: AlR ¹ R ² R ³ (wherein R ¹ to R ³ are each independently an unsubstituted or substituted alkyl group, an unsubstituted or substituted group, A good cycloalkyl group, an unsubstituted or substituted aryl group, an unsubstituted or substituted aralkyl group, an unsubstituted or substituted alkoxyl group, an unsubstituted or substituted aryloxy Or an N, N-disubstituted amino group, wherein R ² and R ³ may be an unsubstituted or substituted aryleneoxy group formed by combining them. .
Examples of the organoaluminum compound include isobutylbis (2,6-di-tert-butyl-4-methylphenoxy) aluminum, isobutylbis (2,6-di-tert-butylphenoxy) aluminum, and isobutyl [2,2′- Methylenebis (4-methyl-6-tert-butylphenoxy)] aluminum and the like.
In the anionic polymerization method, an ether and a nitrogen-containing compound can coexist in order to control the polymerization reaction.

(Methacrylic resin (M2))
The methacrylic resin (M2) is not particularly limited as long as the α relaxation temperature T _α2 is 132 ° C. or lower when the dynamic viscoelasticity measurement is performed in a tensile mode and a sine wave of 1 Hz. One or more methacrylic resins (M2) can be used. The methacrylic resin (M2) contains one or more methacrylic acid ester monomer units such as MMA monomer units. Examples of methacrylic acid esters include MMA, ethyl methacrylate, and methacrylic acid alkyl esters such as butyl methacrylate; aryl methacrylates such as phenyl methacrylate; methacrylic acid cycloalkyl esters such as cyclohexyl methacrylate and norbornenyl methacrylate. Is mentioned. Among these, methacrylic acid alkyl ester is preferable, and MMA is most preferable.

The content of the methacrylic acid ester monomer unit in the methacrylic resin (M2) is preferably 90% by mass or more, more preferably 95% by mass or more, further preferably 98% by mass or more, particularly preferably 99% by mass or more, Most preferably, it is 100 mass%.
The content of the MMA monomer unit in the methacrylic resin (M2) is preferably 90% by mass or more, more preferably 95% by mass or more, further preferably 98% by mass or more, particularly preferably 99% by mass or more, and most preferably. Is 100% by mass.

The methacrylic resin (M2) may contain one or more monomer units other than the methacrylic acid ester monomer unit. Other monomer units include: alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate; aryl acrylates such as phenyl acrylate; In one molecule such as cycloalkyl acrylate such as cyclohexyl acrylate and norbornenyl acrylate; aromatic vinyl compounds such as styrene and α-methylstyrene; acrylamide and methacrylamide; nitriles such as acrylonitrile and methacrylonitrile And structural units derived from vinyl monomers having only one polymerizable carbon-carbon double bond.

The Mw of the methacrylic resin (M2) is preferably 40,000 to 200,000, more preferably 50,000 to 150,000, and particularly preferably 50,000 to 120,000. There exists a tendency for the mechanical strength (impact resistance, toughness, etc.) of the molded object obtained by Mw to be 40,000 or more, and when it is 200,000 or less, the fluidity of the methacrylic resin composition is improved and the moldability is increased. Tend to improve.

The molecular weight distribution (Mw / Mn) of the methacrylic resin (M2) is preferably 1.6 to 5.0, more preferably 1.7 to 4.0, and particularly preferably 1.7 to 3.0. When a methacrylic resin (M2) having a molecular weight distribution (Mw / Mn) within such a range is used, the resulting molded article is excellent in mechanical strength. Mw and Mw / Mn can be controlled by adjusting the type and / or amount of the polymerization initiator used in the production of the methacrylic resin (M2).

The melt flow rate (MFR) of the methacrylic resin (M2) measured under the conditions of 230 ° C. and 3.8 kg load is preferably 0.1 g / 10 min or more, more preferably 0.2 to 30 g / 10 min, especially Preferably it is 0.5 to 20 g / 10 min, and most preferably 1.0 to 15 g / 10 min.

As a method for producing the methacrylic resin (M2), from the viewpoint of productivity, in the radical polymerization method, the polymerization temperature, the polymerization time, the type and / or amount of the chain transfer agent, the type and / or amount of the polymerization initiator are adjusted. Is preferred. The details of the radical polymerization method are as described above.

(Mass ratio)
The methacrylic resin composition of the present invention has a methacrylic resin (M1) / methacrylic resin (M2) mass ratio of 2/98 to 29/71, preferably 5/95 to 28/72, particularly preferably 10/90 to 25. / 75. The methacrylic resin (M1) having a high α relaxation temperature (T _α ) and low thermal decomposition resistance improves the heat resistance of the resin composition. However, when the amount of the methacrylic resin (M1) having a high α relaxation temperature (T _α ) is excessive, the viscosity of the resin composition at the time of molding increases and the moldability deteriorates. In addition, since the methacrylic resin (M1) having a high α relaxation temperature (T _α ) has low heat decomposability, if the amount is excessive, it may be decomposed and foamed during high temperature molding, and the appearance of the resulting molded product may be deteriorated. . If the amount of the methacrylic resin (M1) is too small, desired dimensional stability against heat cannot be obtained. The methacrylic resin (M2) having a low α relaxation temperature (T _α ) improves the moldability of the resin composition. When the mass ratio of the methacrylic resins (M1) and (M2) is within the above range, a methacrylic resin composition having both good high-temperature moldability and high dimensional stability against heat of the molded body can be obtained.

The methacrylic resin composition of the present invention has η ₁ > η ₂ when the melt viscosity of the methacrylic resin (M1) and the methacrylic resin (M2) at 260 ° C. and a shear rate of 122 sec ⁻¹ is η ₁ and η ₂ , respectively. It is. By melt viscosity eta ₁ of the methacrylic resin (M2) from α relaxation temperature is high methacrylic resin (M1) is higher than the melt viscosity eta ₂ of the methacrylic resin (M2), a methacrylic resin during molding of the methacrylic resin composition (M1) Are easy to orient and difficult to relax, the resulting molded product can exhibit good mechanical strength and high dimensional stability. In addition, this effect can be expressed even if the content ratio of the methacrylic resin (M1) is not large.

The total amount of the methacrylic resins (M1) and (M2) in the methacrylic resin composition of the present invention is preferably 80% by mass or more, more preferably 85% by mass or more, particularly preferably 90% by mass or more, and most preferably 92%. It is at least mass%.
The methacrylic resin composition comprising only the methacrylic resins (M1) and (M2) has an Mw of preferably 50,000 to 200,000, more preferably 52,000 to 150,000, particularly preferably 55,000 to 120,000, and a molecular weight distribution (Mw / Mn). Preferably it is 1.2 to 2.0, more preferably 1.3 to 1.8. When the Mw and the molecular weight distribution (Mw / Mn) are in such ranges, the moldability of the methacrylic resin composition becomes good, and it becomes easy to obtain a molded body excellent in mechanical strength (impact resistance, toughness, etc.).
The methacrylic resin composition consisting only of the methacrylic resins (M1) and (M2) has a melt flow rate (MFR) measured at 230 ° C. and a load of 3.8 kg, preferably 0.1 g / 10 min or more. It is preferably 0.2 to 30 g / 10 minutes, particularly preferably 0.5 to 20 g / 10 minutes, and most preferably 1.0 to 10 g / 10 minutes.

(Other polymers)
The methacrylic resin composition of this invention can contain 1 or more types of other polymers other than a methacrylic resin (M1) and (M2) as needed. The other polymer may be added during or after polymerization of the methacrylic resin (M1) and / or methacrylic resin (M2), or may be added during kneading of the methacrylic resins (M1) and (M2). Good.

Other polymers include polyolefin resins such as polyethylene, polypropylene, polybutene-1, poly-4-methylpentene-1, and polynorbornene; ethylene ionomers; polystyrene, styrene-maleic anhydride copolymer, high impact polystyrene Styrene resins such as AS resin, ABS resin, AES resin, AAS resin, ACS resin, and MBS resin; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polyamide resins such as nylon 6, nylon 66, and polyamide elastomer; Polycarbonate; polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, polyvinyl alcohol, polyvinyl butyral, polyvinyl acetal, polyvinyl phenol, and ethylene Polyacetal; polyurethane; modified polyphenylene ether and polyphenylene sulfide; silicone modified resin; acrylic rubber, acrylic thermoplastic elastomer, and silicone rubber; styrene thermoplastic elastomer such as SEPS, SEBS, and SIS; Examples thereof include olefinic rubbers such as IR, EPR, and EPDM. The amount of the other polymer in the methacrylic resin composition of the present invention is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 0% by mass.

(Preferred embodiment)
In a preferred embodiment, the methacrylic resin composition of the present invention can contain methacrylic resins (M1) and (M2) and a polycarbonate resin (PC) and / or a phenoxy resin (PR). One or two or more of polycarbonate resin (PC) and phenoxy resin (PR) can be used. By including the polycarbonate resin (PC) and / or the phenoxy resin (PR), it is possible to obtain a methacrylic resin composition in which the retardation can be easily adjusted. The amount of the polycarbonate resin (PC) and / or the phenoxy resin (PR) is preferably 1.0 to 10 parts by mass, more preferably 1 with respect to 100 parts by mass of the total amount of the methacrylic resins (M1) and (M2). 0.5 to 7 parts by mass, particularly preferably 2.0 to 6 parts by mass.

<Polycarbonate resin (PC)>
Examples of the polycarbonate resin (PC) include a polymer obtained by a reaction between a polyfunctional hydroxy compound and a carbonate ester-forming compound. From the viewpoint of compatibility with methacrylic resins and the transparency of the resulting molded article, aromatic polycarbonate resins are preferred.
Polycarbonate resin (PC) is melt volume flow rate (MVR) measured under conditions of 300 ° C. and 1.2 kg load from the viewpoints of compatibility with methacrylic resin and transparency and surface smoothness of the resulting molded product. but preferably 130 ~ 250cm ^3/10 min,
More preferably 150 ~ 230cm ^3/10 min, particularly preferably 180 ~ 220cm ^3/10 min.
The polycarbonate resin (PC) has a polystyrene-equivalent Mw of preferably 15000 to 28000, more preferably 18000 to 27000, particularly from the viewpoints of compatibility with the methacrylic resin and the transparency and surface smoothness of the resulting molded product. Preferably it is 20000-24000.
The MVR and Mw of the polycarbonate resin (PC) can be controlled by adjusting the amount of the terminal terminator and / or branching agent.
The 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 Tg is usually 180 ° C.

Examples of the method for producing the polycarbonate resin (PC) include a phosgene method (interfacial polymerization method) and a melt polymerization method (transesterification method). The aromatic polycarbonate resin can be produced by subjecting a polycarbonate resin raw material produced by a melt polymerization method to a treatment for adjusting the amount of terminal hydroxy groups.
The polycarbonate resin (PC) may contain other structural units such as polyester, polyurethane, polyether, or polysiloxane in addition to the polycarbonate structural unit.

<Phenoxy resin (PR)>
The phenoxy resin (PR) is a thermoplastic polyhydroxy polyether resin. A phenoxy resin (PR) can contain 50 mass% or more of 1 or more types of structural units represented by following formula (1).

In the formula (1), X is a divalent group containing at least one benzene ring, and R is a linear or branched alkylene group having 1 to 6 carbon atoms. The structural unit represented by the formula (1) may be connected in any form of random, alternating, or block.
The phenoxy resin (PR) preferably contains 10 to 1000 structural units represented by the formula (1), more preferably 15 to 500, and particularly preferably 30 to 300.

It is preferable that the phenoxy resin (PR) does not have an epoxy group at the terminal because it is easy to obtain a molded product with few gel defects.
Mn in terms of polystyrene of the phenoxy resin (PR) is preferably 3000 to 2000000, more preferably 5000 to 100,000, and particularly preferably 10,000 to 50000. When Mn is in such a range, a methacrylic resin composition having high heat resistance and high strength can be obtained.
The Tg of the phenoxy resin (PR) is preferably 80 ° C. or higher, more preferably 90 ° C. or higher, and particularly preferably 95 ° C. or higher. If the Tg of the phenoxy resin (PR) is too low, the heat resistance of the methacrylic resin composition tends to be low. The upper limit of Tg is preferably 150 ° C. When the Tg of the phenoxy resin (PR) is excessively high, the obtained molded product tends to become brittle.

The phenoxy resin (PR) can be obtained from, for example, a condensation reaction between a dihydric phenol compound and an epihalohydrin or a polyaddition reaction between a dihydric phenol compound and a bifunctional epoxy resin. This reaction can be carried out without solvent or in a solvent.

Dihydric phenol compounds include hydroquinone, resorcin, 4,4-dihydroxybiphenyl, 4,4′-dihydroxydiphenyl ketone, 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) ) Cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2- Bis (4-hydroxyphenyl) butane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, bis (4-hydroxyphenyl) diphenylmethane, 2,2-bis (4-hydroxy-3-methylphenyl) Propane, 2,2-bis (3-phenyl-4-hydroxyphenyl) propa 2,2-bis (4-hydroxy-3-tert-butylphenyl) propane, 1,3-bis (2- (4-hydroxyphenyl) propyl) benzene, 1,4-bis (2- (4-hydroxy) Phenyl) propyl) benzene, 2,2-bis (4-hydroxyphenyl) -1,1,1-3,3,3-hexafluoropropane, 9,9′-bis (4-hydroxyphenyl) fluorene, etc. Can be mentioned. Among these, 4,4-dihydroxybiphenyl, 4,4′-dihydroxydiphenyl ketone, 2,2-bis (4-hydroxyphenyl) propane, and 9,9′-bis (4-hydroxyphenyl) are considered in view of physical properties and cost. Fluorene is preferred.

Examples of the bifunctional epoxy resins include epoxy oligomers obtained by condensation reaction of the above divalent phenol compound and epihalohydrin. Specifically, hydroquinone diglycidyl ether, resorcin diglycidyl ether, bisphenol S type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, methyl hydroquinone diglycidyl ether, chlorohydroquinone diglycidyl ether, 4,4'- Dihydroxydiphenyl oxide diglycidyl ether, 2,6-dihydroxynaphthalenediglycidyl ether, dichlorobisphenol A diglycidyl ether, and tetrabromobisphenol A type epoxy resin, 9,9′-bis (4) -hydroxyphenyl) fluorenediglycidyl ether Etc. Among these, bisphenol A type epoxy resin, bisphenol S type epoxy resin, hydroquinone diglycidyl ether, bisphenol F type epoxy resin, tetrabromobisphenol A type epoxy resin, and 9,9'-bis (4)- Hydroxyphenyl) full orange glycidyl ether is preferred.

Examples of the solvent used for the production of the phenoxy resin (PR) include aprotic organic solvents such as methyl ethyl ketone, dioxane, tetrahydrofuran, acetophenone, N-methylpyrrolidone, dimethyl sulfoxide, N, N-dimethylacetamide, and sulfolane.
Examples of the catalyst used for the production of the phenoxy resin (PR) include alkali metal hydroxides, tertiary amine compounds, quaternary ammonium compounds, tertiary phosphine compounds, and quaternary phosphonium compounds.

X in the formula (1) is preferably a divalent group derived from the compounds represented by the following formulas (2) to (4). In addition, the position of the two bonds constituting the divalent group is not particularly limited as long as it is a chemically possible position. X in the formula (1) is preferably a divalent group having two bonds formed by extracting two hydrogen atoms from the benzene ring in the compounds represented by the formulas (2) to (4). In particular, a divalent group having two bonds formed by extracting one hydrogen atom from any two benzene rings in the compounds represented by formulas (3) to (4) is preferable.

In formula (2), R ⁴ is a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a linear or branched alkenyl group having 2 to 6 carbon atoms. p is an integer of 1 to 4.

In Formula (3), R ¹ is a single bond, a linear or branched alkylene group having 1 to 6 carbon atoms, a cycloalkylene group having 3 to 20 carbon atoms, or a cycloalkylidene group having 3 to 20 carbon atoms. . In formulas (3) and (4), R ² and R ³ are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a linear or branched chain having 2 to 6 carbon atoms. Of the alkenyl group. n and m are each independently an integer of 1 to 4.

In formula (1), X may be a divalent group derived from a compound in which a plurality of benzene rings are condensed with an alicyclic ring or a heterocyclic ring. For example, a divalent group derived from a compound having a fluorene structure or a carbazole structure can be given.

The structural unit represented by the formula (1) is preferably a structural unit represented by the following formulas (5) and (6), more preferably a structural unit represented by the following formula (7). The phenoxy resin (PR) of a preferred embodiment preferably contains 10 to 1000 such structural units.

In formula (5), R ⁹ is a single bond, a linear or branched alkylene group having 1 to 6 carbon atoms, a cycloalkylene group having 3 to 20 carbon atoms, or a cycloalkylidene group having 3 to 20 carbon atoms. . In the formulas (5) and (6), R ¹⁰ is a linear or branched alkylene group having 1 to 6 carbon atoms.

Examples of commercially available phenoxy resins (PR) include YP-50 and YP-50S manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., jER series manufactured by Mitsubishi Chemical Co., Ltd., PKFE and PKHJ manufactured by InChem.

(Other preferred embodiments)
In another preferred embodiment, the methacrylic resin composition of the present invention can include methacrylic resins (M1) and (M2) and a crosslinked rubber (CR) and / or a block copolymer (BP). Either one or two or more of the crosslinked rubber (CR) and the block copolymer (BP) can be used.

<Crosslinked rubber (CR)>
Crosslinked rubber (CR) is a polymer having rubber elasticity in which a plurality of polymer chains are crosslinked by a crosslinkable monomer having a plurality of polymerizable functional groups in one monomer. As the crosslinked rubber (CR), an acrylic crosslinked rubber containing an alkyl acrylate monomer unit and a crosslinkable monomer unit, a diene containing a conjugated diene monomer unit and a crosslinkable monomer unit Examples thereof include a crosslinked rubber, a crosslinked rubber containing an alkyl acrylate monomer unit, a conjugated diene monomer unit, and a crosslinkable monomer unit. These cross-linked rubbers can contain other vinyl monomer units as required.

The crosslinked rubber (CR) is preferably in the form of particles. The cross-linked rubber particles (CRp) may be single-layer particles composed only of a cross-linked rubber polymer, or may be multi-layer particles of two or more layers composed of a cross-linked rubber polymer and another polymer. The multilayer particle is preferably a core-shell type particle composed of a core part made of a crosslinked rubber polymer and a shell part made of another polymer. In the core-shell type particle, the core part may have a center core part and, if necessary, one or more inner shell layers covering the center core part, and the shell part may have one outer shell layer covering the core part. . There are preferably no gaps between the layers. As the core-shell type particles, acrylic multilayer polymer particles (CRa) are particularly preferable.

In the core-shell type particles, at least a part of the core portion composed of the center core portion and, if necessary, one or more inner shell layers contains the crosslinked rubber polymer (i). When there is a remainder that does not contain the crosslinked rubber polymer (i) in the core part, this remainder contains another polymer (iii). When a plurality of portions of the core portion contain the crosslinked rubber polymer (i), the kind and physical properties of the crosslinked rubber polymer (i) contained therein may be the same or non-identical. Similarly, when the plurality of remaining portions of the core portion contain other polymer (iii), the types and physical properties of the other polymer (iii) contained therein may be the same or non-identical.

As the crosslinked rubber polymer (i), those containing an alkyl acrylate monomer unit and / or a conjugated diene monomer unit and a crosslinkable monomer unit are preferable. The carbon number of the alkyl group of the acrylic acid alkyl ester monomer used in the crosslinked rubber polymer (i) is preferably 1-8. Examples of the alkyl acrylate monomer include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. These can be used alone or in combination of two or more. Examples of the conjugated diene monomer include butadiene and isoprene. These can be used alone or in combination of two or more. The amount of the acrylic acid alkyl ester monomer unit and / or the conjugated diene monomer unit in the crosslinked rubber polymer (i) is preferably 60% by mass or more, more preferably 70 to 99% by mass, particularly preferably. 80 to 98% by mass.

Crosslinkable monomers include allyl acrylate, allyl methacrylate, 1-acryloxy-3-butene, 1-methacryloxy-3-butene, 1,2-diacryloxy-ethane, 1,2-dimethacryloxy-ethane, 1, 2-Diacryloxy-propane, 1,3-diacryloxy-propane, 1,4-diacryloxy-butane, 1,3-dimethacryloxy-propane, 1,2-dimethacryloxy-propane, 1,4-dimethacryloxy-butane, triethylene glycol di Examples include methacrylate, hexanediol dimethacrylate, triethylene glycol diacrylate, hexanediol diacrylate, divinylbenzene, 1,4-pentadiene, and triallyl isocyanate. These can be used alone or in combination of two or more. The amount of the crosslinkable monomer unit in the crosslinked rubber polymer (i) is preferably 0.05 to 10% by mass, more preferably 0.5 to 7% by mass, and particularly preferably 1 to 5% by mass. .

The crosslinked rubber polymer (i) can contain other vinyl monomer units as necessary. Other vinyl monomers include MMA, ethyl methacrylate, butyl methacrylate, and methacrylic acid ester monomers such as cyclohexyl methacrylate; aromatic vinyl such as styrene, p-methylstyrene, and o-methylstyrene. Monomers; maleimide monomers such as N-propylmaleimide, N-cyclohexylmaleimide, and No-chlorophenylmaleimide. These can be used alone or in combination of two or more.

The other polymer (iii) is preferably one having a methacrylic acid alkyl ester monomer unit. The other polymer (iii) can contain a crosslinkable monomer unit and / or other vinyl monomer units as required.
The methacrylic acid alkyl ester monomer used in the other polymer (iii) preferably has 1 to 8 carbon atoms. Such methacrylic acid alkyl ester monomers include MMA, ethyl methacrylate, butyl methacrylate and the like, and MMA is preferred. These can be used alone or in combination of two or more. The amount of the methacrylic acid alkyl ester monomer unit in the other polymer (iii) is preferably 80 to 100% by mass, more preferably 85 to 99% by mass, and particularly preferably 90 to 98% by mass.
As the crosslinkable monomer used in the other polymer (iii), the same crosslinkable monomers as exemplified in the crosslinked rubber polymer (i) can be used. The amount of the crosslinkable monomer unit in the other polymer (iii) is preferably 0 to 5% by mass, more preferably 0.01 to 3% by mass, and particularly preferably 0.02 to 2% by mass. .

Other vinyl monomers used in other polymers (iii) include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, cyclohexyl acrylate, phenyl acrylate, acrylic acid Acrylic ester monomers such as benzyl and 2-ethylhexyl acrylate; vinyl acetate; aromatic vinyl such as styrene, p-methylstyrene, m-methylstyrene, o-methylstyrene, α-methylstyrene, and vinylnaphthalene Monomers; Nitriles such as acrylonitrile and methacrylonitrile; α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; maleimide monomers such as N-ethylmaleimide and N-cyclohexylmaleimide Is mentioned. These can be used alone or in combination of two or more.

In the core-shell type particle, the shell portion composed of one or more outer shell layers preferably contains the thermoplastic polymer (ii). As the thermoplastic polymer (ii), those having a methacrylic acid alkyl ester monomer unit and, if necessary, other vinyl monomer units are preferred. At least a part of the thermoplastic polymer (ii) is preferably grafted to the center core layer or inner shell layer adjacent to the inside.

The carbon number of the methacrylic acid alkyl ester monomer unit in the thermoplastic polymer (ii) is preferably 1 to 8. Such methacrylic acid alkyl ester monomers include MMA and butyl methacrylate, and MMA is preferred. These can be used alone or in combination of two or more. The amount of the methacrylic acid alkyl ester monomer unit in the thermoplastic polymer (ii) is preferably 80% by mass or more, more preferably 85% by mass or more, and particularly preferably 90% by mass or more.

As other vinyl monomers used in the thermoplastic polymer (ii), the same vinyl monomers as those exemplified in the other polymer (iii) described above can be used. The amount of other vinyl monomer units in the thermoplastic polymer (ii) is preferably 20% by mass or less, more preferably 15% by mass or less, and particularly preferably 10% by mass or less.

In the core-shell type particle, the core part and the shell part are composed of two-layer polymer particles in which the center core part is made of a crosslinked rubber polymer (i) and the outer shell layer is made of a thermoplastic polymer (ii); Is composed of another polymer (iii), the inner shell layer is composed of a crosslinked rubber polymer (i), and the outer shell layer is composed of a thermoplastic polymer (ii); Three-layer polymer particles comprising a kind of crosslinked rubber polymer (i), the inner shell layer comprising another kind of crosslinked rubber polymer (i), and the outer shell layer comprising a thermoplastic polymer (ii); Three-layer polymer particles in which the center core portion is composed of a crosslinked rubber polymer (i), the inner shell layer is composed of another polymer (iii), and the outer shell layer is composed of a thermoplastic polymer (ii); Consists of a crosslinked rubber polymer (i) and has a first inner sheath. For example, four layer polymer particles in which the second layer is made of another polymer (iii), the second inner shell layer is made of a crosslinked rubber polymer (i), and the outer shell layer is made of a thermoplastic polymer (ii). It is done.

Among these, an acrylic three-layer structure in which the center core portion is made of another polymer (iii), the inner shell layer is made of a crosslinked rubber polymer (i), and the outer shell layer is made of a thermoplastic polymer (ii). Combined particles are preferred. Further, the other polymer (iii) in the center core portion is an acrylate monomer unit having an MMA monomer unit of 80 to 99.95% by mass and having an alkyl group having 1 to 8 carbon atoms. Acrylic acid having 95% by mass and a crosslinkable monomer unit of 0.05 to 2% by mass, wherein the crosslinked rubber polymer (i) of the inner shell layer has an alkyl group having 1 to 8 carbon atoms. A copolymer of 80 to 98% by mass of an alkyl ester monomer unit, 1 to 19% by mass of an aromatic vinyl monomer unit and 1 to 5% by mass of a crosslinkable monomer unit, and the thermoplastic weight of the outer shell layer Acrylic three-layer copolymer in which the compound (ii) is a copolymer of 80 to 100% by mass of MMA monomer units and 0 to 20% by mass of alkyl acrylate monomer units having an alkyl group having 1 to 8 carbon atoms Combined particles are particularly preferred.

From the viewpoint of transparency of the core-shell type particles, the difference in refractive index between adjacent layers is preferably less than 0.005, more preferably less than 0.004, and particularly preferably less than 0.003. It is preferred to select a polymer.
The proportion of the outer shell layer in the core-shell type particle is preferably 10 to 60% by mass, more preferably 15 to 50% by mass, and particularly preferably 20 to 40% by mass. The ratio of the portion containing the crosslinked rubber polymer (i) in the core is preferably 20 to 100% by mass, more preferably 30 to 70% by mass.

The volume-based average particle diameter of the crosslinked rubber particles (CRp) is preferably 0.02 to 1 μm, more preferably 0.05 to 0.5 μm, and particularly preferably 0.1 to 0.3 μm. When cross-linked rubber particles (CRp) having such a volume-based average particle diameter are used, the appearance defect of the obtained molded product can be remarkably reduced. In the present specification, the “volume reference average particle size” is a value calculated based on particle size distribution data measured by a light scattering method.

As a method for producing the crosslinked rubber particles (CRp), an emulsion polymerization method or a seed emulsion polymerization method is preferable from the viewpoints of particle diameter control and ease of production of a multilayer structure. The emulsion polymerization method is a method for producing an emulsion containing polymer particles by emulsion polymerization of one or more raw material monomers. In the seed emulsion polymerization method, seed particles are obtained by emulsion polymerization of one or more kinds of raw material monomers, and then emulsion polymerization of other raw material monomers in the presence of the seed particles. An emulsion containing core-shell polymer particles comprising a shell layer covering the same can be produced. Emulsion comprising core-shell multilayer polymer particles comprising seed particles and a plurality of shell layers covering them by repeating the step of emulsion polymerization of one or more raw material monomers in the presence of the obtained core-shell polymer particles Can be manufactured.

Examples of the emulsifier used in the emulsion polymerization method include an anionic emulsifier, a nonionic emulsifier, and a nonionic anionic emulsifier. Examples of anionic emulsifiers include dialkyl sulfosuccinates such as sodium dioctyl sulfosuccinate and sodium dilauryl sulfosuccinate; alkyl benzene sulfonates such as sodium dodecylbenzene sulfonate; alkyl sulfates such as sodium dodecyl sulfate. Examples of nonionic emulsifiers include polyoxyethylene alkyl ether and polyoxyethylene nonylphenyl ether. Nonionic and anionic emulsifiers include polyoxyethylene nonylphenyl ether sulfate such as sodium polyoxyethylene nonylphenyl ether sulfate; polyoxyethylene alkyl ether sulfate such as sodium polyoxyethylene alkyl ether sulfate: polyoxyethylene tridecyl ether Examples thereof include alkyl ether carboxylates such as sodium acetate. These can be used alone or in combination of two or more. The average number of repeating units of ethylene oxide (EO) units in the exemplified compounds of the nonionic emulsifier and the nonionic anionic emulsifier is preferably 30 or less, more preferably in order to prevent the foaming property of the emulsifier from becoming extremely large. 20 or less, particularly preferably 10 or less.
Examples of the polymerization initiator used in emulsion polymerization include persulfate initiators such as potassium persulfate and ammonium persulfate; redox initiators such as persulfoxylate / organic peroxide and persulfate / sulfite. It is done.

Examples of the method for separating the crosslinked rubber particles (CRp) from the emulsion obtained by emulsion polymerization include a salting out coagulation method, a freeze coagulation method, and a spray drying method. Among these, the salting-out coagulation method and the freeze coagulation method are preferable, and the freeze coagulation method is more preferable because impurities contained in the crosslinked rubber particles (CRp) can be easily removed by washing with water. According to the freeze coagulation method without using a flocculant, a resin composition excellent in water resistance can be easily obtained. In addition, it is preferable to filter the emulsion with a wire mesh or the like having an opening of 50 μm or less before the coagulation step because foreign matters mixed in the emulsion can be removed.

From the viewpoint of particle dispersibility in the melt kneading of the methacrylic resins (M1) and (M2) and the crosslinked rubber particles (CRp), the crosslinked rubber particles (CRp) are preferably aggregates having a diameter of 1000 μm or less, more preferably 500 μm or less. It is preferable to take it out in the form of a collection. In addition, as an aggregation form, the form which shell parts mutually fused is mentioned. Examples of the shape of the crosslinked rubber particle aggregate include pellets, powders, and granules.

The amount of the crosslinked rubber (CR) in the methacrylic resin composition of the present invention is preferably 5 to 30 parts by mass, more preferably 10 to 10 parts by mass with respect to 100 parts by mass of the total amount of the methacrylic resins (M1) and (M2). The amount is 25 parts by mass, particularly preferably 15 to 20 parts by mass.

In the methacrylic resin composition of the present invention, dispersion auxiliary particles (DA) such as methacrylic resin particles can be added in order to improve the uniform dispersibility of the crosslinked rubber particles (CRp). The volume-based average particle diameter of the dispersion assisting particles (DA) is preferably smaller than the crosslinked rubber particles (CRp), preferably 0.04 to 0.12 μm, more preferably 0.05 to 0.1 μm. From the viewpoint of improving dispersibility and the like, the mass ratio of dispersion aid particles (DA) / crosslinked rubber particles (CRp) is preferably 0/100 to 60/40, more preferably 10/90 to 50/50, and particularly preferably. Is 20/80 to 40/60.

<Block copolymer (BP)>
The block copolymer (BP) is a copolymer in which a plurality of types of polymer molecular chains (polymer blocks) are connected in a chain or radial form as a whole. From the viewpoint of compatibility with the methacrylic resins (M1) and (M2), at least one of the polymer blocks constituting the block copolymer (BP) has a weight containing 90% by mass or more of a methacrylic acid ester monomer unit. Polymers containing styrene monomer units and acrylonitrile monomer units, polymers containing styrene monomer units and maleic anhydride monomer units, styrene monomer units and maleic anhydride monomers It is preferable to include a polymer containing units and MMA monomer units, or polyvinyl butyral.

From the viewpoint of improving the strength of the molded product, the block copolymer (BP) may be one or more polymer blocks (b1) (methacrylic ester polymer) comprising a polymethacrylic ester such as polymethyl methacrylate (PMMA). A block copolymer (BPa) containing a block) and one or more polymer blocks (b2) (acrylic acid ester polymer block) made of polyacrylic acid ester is preferable.
As a method for producing a block copolymer (BPa), a polymerization initiation point is created at the end of one polymer block using living polymerization, and a monomer is polymerized from this initiation point to connect the other polymer block. A method of producing: a method of preparing a plurality of types of polymer blocks and subjecting them to addition reaction or condensation reaction, and the like.

The amount of the block copolymer (BP) is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 25 parts by mass with respect to 100 parts by mass of the total amount of the methacrylic resins (M1) and (M2). Particularly preferred is 1 to 20 parts by mass.

(Other optional ingredients)
The methacrylic resin composition of the present invention can contain other optional components as required. Other optional components include fillers, antioxidants, thermal degradation inhibitors, UV absorbers, light stabilizers, lubricants, mold release agents, polymer processing aids, antistatic agents, flame retardants, dyes and pigments, and light diffusion. And various additives such as agents, organic dyes, matting agents, impact modifiers, and phosphors. The total amount of these various additives is preferably 7% by mass or less, more preferably 5% by mass or less, and particularly preferably 4% by mass or less.

<Ultraviolet absorber (LA)>
If the molecular weight of the ultraviolet absorber (LA) is too small, foaming may occur during molding of the methacrylic resin composition. Therefore, the molecular weight of the ultraviolet absorber (LA) is preferably more than 200, more preferably 300 or more, particularly preferably 500 or more, and most preferably 600 or more.
An ultraviolet absorber (LA) is a compound said to have a function of converting light energy into heat energy. Examples of the ultraviolet absorber (LA) include benzophenones, benzotriazoles, triazines, benzoates, salicylates, cyanoacrylates, succinic anilides, malonic esters, and formamidines. These can be used alone or in combination of two or more. Benzotriazoles (compounds having a benzotriazole skeleton) and triazines (compounds having a triazine skeleton) are preferable because they have a high effect of suppressing deterioration (such as yellowing) of the resin due to ultraviolet rays.

Examples of benzotriazoles include 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), 2,2′-methylenebis [6- (2H-benzotriazole-2 -Yl) -4-tert-octylphenol] (manufactured by ADEKA; LA-31), 2- (5-octylthio-2H-benzotriazol-2-yl) -6-tert-butyl-4-methylphenol and the like Can be mentioned.

Examples of triazines include 2,4,6-tris (2-hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine (manufactured by ADEKA; LA-F70) and its analogs. Certain hydroxyphenyltriazine-based ultraviolet absorbers (manufactured by BASF; CGL777, TINUVIN460, TINUVIN479, etc.), 2,4-diphnyl-6- (2-hydroxy-4-hexyloxyphenyl) -1,3,5-triazine, etc. Is mentioned.

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

In addition, WO 2011/089794, WO 2012/124395, JP 2012-012476, JP 2013-023461, JP 2013-112790, JP 2013-194037, Examples thereof include metal complexes having a heterocyclic ligand as described in JP-A No. 2014-62228, JP-A No. 2014-88542, JP-A No. 2014-88543, and the like. Examples of such metal complexes include compounds represented by the following formula (A).

In formula (A), M is a metal atom. Y ¹ to Y ⁴ are each independently a divalent group other than a carbon atom (oxygen atom, sulfur atom, NH, NR ^5, etc.). R ⁵ is a substituent such as an alkyl group, an aryl group, a heteroaryl group, a heteroaralkyl group, and an araryl group. The substituent may further have a substituent. Z ¹ and Z ² are each independently a trivalent group (such as a nitrogen atom, CH, and CR ⁶ ). R ⁶ is a substituent such as an alkyl group, an aryl group, a heteroaryl group, a heteroaralkyl group, and an araryl group. The substituent may further have a substituent. R ¹ to R ⁴ are each independently a hydrogen atom, alkyl group, hydroxyl group, carboxyl group, alkoxyl group, halogeno group, alkylsulfonyl group, monomorpholinosulfonyl group, piperidinosulfonyl group, thiomorpholinosulfonyl group, and A substituent such as a piperazinosulfonyl group. The substituent may further have a substituent. a to d each represent the number of R ¹ to R ⁴ and are each independently an integer of 1 to 4.

As the ligand of the heterocyclic structure in the above metal complex, 2,2′-iminobisbenzothiazole, 2- (2-benzothiazolylamino) benzoxazole, 2- (2-benzothiazolylamino) benzo Imidazole, (2-benzothiazolyl) (2-benzimidazolyl) methane, bis (2-benzoxazolyl) methane, bis (2-benzothiazolyl) methane, bis [2- (N-substituted) benzimidazolyl] methane, and derivatives thereof Etc. As the central metal of the metal complex, copper, nickel, cobalt, zinc and the like are preferable. The metal complex is preferably used by being dispersed in a medium such as a low molecular compound or a polymer. The amount of the metal complex added is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 2 parts by mass with respect to 100 parts by mass of the methacrylic resin composition of the present invention. Since the metal complex has a large molar extinction coefficient at a wavelength of 380 to 400 nm, the amount to be added is small in order to obtain a desired ultraviolet absorption effect. Therefore, it is possible to suppress deterioration of the appearance of the molded body due to bleeding out or the like. Further, since the metal complex has high heat resistance, there is little deterioration and decomposition during molding. Furthermore, since the metal complex has high light resistance, it can maintain ultraviolet absorption performance for a long time.

The maximum value ε _max of the molar extinction coefficient of the ultraviolet absorber can be measured as follows. 10.00 mg of an ultraviolet absorber is added to 1 L of cyclohexane and dissolved so that there is no undissolved substance 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 measured maximum absorbance value (A _max ) according to the following equation.
ε _max = [A _max / (10 × 10 ⁻³ )] × M _UV

<Polymer processing aid (PA)>
As the polymer processing aid (PA), polymer particles (non-crosslinked rubber particles) having a particle diameter of 0.05 to 0.5 μm, which can be produced by an emulsion polymerization method, can be used. The polymer particle may be a single-layer particle composed of a polymer having a single composition and a single intrinsic viscosity, or may be a multilayer particle composed of two or more layers composed of two or more polymers having different compositions or intrinsic viscosities. May be. Among these, particles having a two-layer structure having a polymer layer having a low intrinsic viscosity in the inner layer and a polymer layer having a high intrinsic viscosity of 5 dl / g or more in the outer layer are preferable. The polymer processing aid (PA) preferably has an intrinsic viscosity of 3 to 6 dl / g. If the intrinsic viscosity is too small, the moldability improving effect may be insufficient, and if it is too large, the moldability of the methacrylic resin composition may be lowered. Specific examples include the Metablene-P series manufactured by Mitsubishi Rayon Co., and the Paraloid series manufactured by Dow. The amount of the polymer processing aid (PA) is preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the total amount of the methacrylic resins (M1) and (M2). If the amount is too small, good processing characteristics cannot be obtained, and if the amount is too large, the appearance of the molded article may be deteriorated.

<Other additives>
Examples of the filler include calcium carbonate, talc, carbon black, titanium oxide, silica, clay, barium sulfate, and magnesium carbonate. The amount of the filler in the methacrylic resin composition of the present invention is preferably 3% by mass or less, more preferably 1.5% by mass or less.

Examples of the antioxidant include phosphorus antioxidants, hindered phenol antioxidants, and thioether antioxidants. One type or two or more types of antioxidants can be used. 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 combination of a phosphorus-based antioxidant and a hindered phenol-based antioxidant is more preferable. When a phosphorus antioxidant and a hindered phenol antioxidant are used in combination, the mass ratio of phosphorus antioxidant: hindered phenol antioxidant is preferably 1: 5 to 2: 1, and 1: 2. ˜1: 1 is more preferred.
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.
As the hindered phenol-based antioxidant, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (manufactured by BASF; trade name IRGANOX 1010), and octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate (manufactured by BASF; trade name IRGANOX1076).

The thermal degradation inhibitor can prevent thermal degradation of the resin by scavenging polymer radicals that are generated when exposed to high heat under substantially oxygen-free conditions. Examples of the thermal deterioration preventive agent include 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 Sumilyzer GS) .

The light stabilizer is a compound that is said to have a function of capturing radicals generated by oxidation by light. And hindered amines such as compounds having a 2,2,6,6-tetraalkylpiperidine skeleton.
Examples of the lubricant include stearic acid, behenic acid, stearamic acid, methylene bisstearamide, hydroxystearic acid triglyceride, paraffin wax, ketone wax, octyl alcohol, and hardened oil.
Examples of the release agent include higher alcohols such as cetyl alcohol and stearyl alcohol; glycerin higher fatty acid esters such as stearic acid monoglyceride and stearic acid diglyceride. The combined use of higher alcohols and glycerin fatty acid monoester is preferred. The mass ratio of higher alcohols / glycerin fatty acid monoester is preferably 2.5 / 1 to 3.5 / 1, more preferably 2.8 / 1 to 3.2 / 1.

As the organic dye, a compound that converts ultraviolet light into visible light is preferably used.
Examples of the light diffusing agent and matting agent include glass fine particles, polysiloxane-based crosslinked fine particles, crosslinked polymer fine particles, talc, calcium carbonate, and barium sulfate.
Examples of the phosphor include a fluorescent pigment, a fluorescent dye, a fluorescent white dye, a fluorescent whitening agent, and a fluorescent bleaching agent.

(Physical properties of methacrylic resin composition)
The methacrylic resin composition of the present invention preferably has an Mw of 50,000 to 200,000, more preferably 55,000 to 160000, particularly preferably 60000 to 120,000, most preferably 70000 to 100,000, and preferably has a molecular weight distribution (Mw / Mn). It is 1.0 to 5.0, more preferably 1.2 to 3.0, particularly preferably 1.3 to 2.0, and most preferably 1.3 to 1.7. When the Mw and the molecular weight distribution (Mw / Mn) are in such ranges, the moldability of the methacrylic resin composition becomes good, and it becomes easy to obtain a molded body excellent in mechanical strength (impact resistance, toughness, etc.).

The melt flow rate (MFR) measured under the conditions of 230 ° C. and 3.8 kg load of the methacrylic resin composition of the present invention is preferably 0.1 to 30 g / 10 minutes, more preferably 0.5 to 20 g / 10. Min, particularly preferably 1.0 to 15 g / 10 min.
In the methacrylic resin composition of the present invention, the haze when processed into a film having a thickness of 3.2 mm is preferably 3.0% or less, more preferably 2.0% or less, and particularly preferably 1.5% or less. is there.

(Method for producing methacrylic resin composition)
As a manufacturing method of the methacrylic resin composition of this invention, the method of melt-kneading a methacryl resin (M1) and (M2) and another polymer as needed is mentioned. The melt kneading can be performed using a melt kneading apparatus such as a kneader ruder, an extruder, a mixing roll, and a Banbury mixer. The kneading temperature can be appropriately adjusted according to the softening temperature of the methacrylic resins (M1) and (M2) and other polymers used as necessary, and is usually within the range of 150 ° C to 300 ° C. The shear rate during kneading can be adjusted within a range of 10 to 5000 sec ⁻¹ .
As another production method of the methacrylic resin composition of the present invention, the other methacrylic resin (M1) and (M2) in the presence of one methacrylic resin and the other polymer used as necessary. There is a method of polymerizing a resin. Since this manufacturing method has a shorter thermal history applied to the methacrylic resin than the above manufacturing method, thermal decomposition of the methacrylic resin is suppressed, and a methacrylic resin composition with less coloring and foreign matter is easily obtained.
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.

"Molded body"
The molded product of the present invention is obtained by molding the above methacrylic resin composition of the present invention. Molding methods include T-die method (lamination method and coextrusion method, etc.), inflation method (coextrusion method, etc.), compression molding method, blow molding method, calender molding method, vacuum molding method, injection molding method (insert method, A melt molding method such as a two-color method, a press method, a core back method, and a sandwich method; and a solution casting method. Of these, the T-die method, the inflation method, the injection molding method, and the like are preferable from the viewpoints of productivity and cost.

"the film"
The form of the molded body is arbitrary, and examples thereof include a film. The film of this invention is a film which consists of said methacryl resin composition of this invention. In general, a planar molded body having a thickness of 5 to 250 μm is mainly classified as “film”, and a planar molded body thicker than 250 μm is mainly classified as “sheet”. It is called “film”.

Examples of the film forming method include a melt film forming method and a solution film forming method, and the melt film forming method is preferable from the viewpoint of productivity. Examples of the melt film forming method include an inflation method, a T-die method, a calendar method, and a cutting method. Of these, the T-die method is preferable. Examples of the melt film forming apparatus include an extruder type melt extrusion apparatus having a single screw or a twin screw. The melt extrusion temperature is preferably 150 to 350 ° C, more preferably 200 to 300 ° C. When melt-kneading using a melt-extrusion apparatus, it is preferable to perform melt-kneading under reduced pressure or inert atmosphere, such as nitrogen, from a viewpoint of coloring suppression. It is preferable to install a polymer filter for removing foreign substances and a gear pump for increasing the thickness accuracy in the melt extrusion apparatus.

In the extrusion method, 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 this is one or more mirror surfaces for cooling. A method of cooling by contacting or pinching with a roll or a mirror belt is preferable. The mirror roll or mirror belt preferably has at least a mirror surface made of chrome-plated metal.

The thickness of the methacrylic resin film (unstretched film) formed by the above method is preferably 10 to 500 μm, more preferably 20 to 200 μm from the viewpoints of mechanical strength, film uniformity, and winding property. . The thickness distribution is preferably within ± 10%, more preferably within ± 5%, and particularly preferably within ± 3% with respect to the average value. If the thickness distribution exceeds ± 10%, stretching unevenness may occur when stretching is performed.

The methacrylic resin film (unstretched film) formed by the above method may be stretched. Stretching increases the mechanical strength (impact resistance and toughness, etc.) and thermophysical properties, and a film that is difficult to crack is obtained. The stretching process includes a stretching process, a heat setting process, and a relaxation process. Examples of the stretching method include a sequential biaxial stretching method, a simultaneous biaxial stretching method, and a tuber stretching method.

In the case of the sequential biaxial stretching method, the stretching speed is preferably 1 to 8,000% / min, more preferably 100 to 6,000% / min in any stretching direction. The stretching speed may be the same or non-identical in the two directions. In the case of the simultaneous biaxial stretching method, the stretching speed is preferably 1 to 8,000% / min, more preferably 50 to 6,000% / min. In either method, productivity is not good if the stretching speed is too low, and film breakage may occur if the stretching speed is too high.

The stretching temperature is preferably Tg to (Tg + 30 ° C.), more preferably (Tg + 5 ° C.) to (Tg + 25 ° C.) in any of the sequential / simultaneous biaxial stretching methods based on the Tg of the methacrylic resin composition of the present invention. It is. In such a range, thickness unevenness is suppressed. If the stretching temperature is too low, the film may be broken, and if it is too high, the effect of improving the mechanical strength and thermophysical properties by the stretching process may be insufficient.

The area ratio of the stretched film to the unstretched film is preferably 1.01 to 12.25 times, more preferably 1.10 to 9 times. If the draw ratio is less than 1.01, the effect of improving the mechanical strength of the film is insufficient, and if it exceeds 12.25, the mechanical strength may be lowered. In the case of biaxial stretching, the stretching ratio in each axial direction is preferably 1.01 to 3.5 times.

The film of the present invention is coated with a polarizer protective film, a retardation film, a liquid crystal protective film, a surface material for a portable information terminal, a display window protective film for a portable information terminal, a light guide film, silver nanowires or carbon nanotubes on the surface. It is suitable for a transparent conductive film and a front film for various displays, and is particularly suitable for a polarizer protective film and the like.
In addition, the film of the present invention includes an IR (infrared) cut film, a crime prevention film, a scattering prevention film, a decorative film, a metal decorative film, a solar battery back sheet, a flexible solar battery front sheet, a shrink film, and an in-mold. It is suitable for a label film and a gas barrier film.
The film of the present invention is also suitable for an optical film for an organic electroluminescence (EL) lighting device.

"Laminated film"
The film (unstretched film or stretched film) of the present invention may be in the form of a laminated film in which another layer is laminated on at least one surface. The laminated film of the present invention has a layer comprising the above-described film of the present invention (unstretched film or stretched film).
Examples of other layers include various functional layers. Examples of the functional layer include a hard coat layer, an antiglare layer, an antireflection layer, an antisticking layer, a diffusion layer, an antiglare layer, an antistatic layer, an antifouling layer, and a slippery layer containing fine particles.

The other layer may be a polarizer made of a polyvinyl alcohol film doped with iodine. The polarizing plate which is one aspect | mode of the laminated | multilayer film of this invention has the said polarizer and the polarizer protective film which consists of said film of this invention laminated | stacked on the at least one surface. In the aspect in which the film of the present invention is laminated on one surface of the polarizer, an optional optical film other than the film of the present invention can be laminated on the other surface of the polarizer as necessary. Examples of the optional optical film include a polarizer protective film other than the film of the present invention, a viewing angle adjustment film, a retardation film, and a brightness enhancement film. Lamination can be performed via an adhesive layer as required.

The polarizing plate of the above aspect can be used for an image display device. Examples of the image display device include self-luminous display devices such as (organic) electroluminescence display (ELD), plasma display (PD), and field emission display (FED); liquid crystal display (LCD) and the like. It is done. The LCD has a liquid crystal cell and a polarizing plate disposed on at least one side thereof.

The other layer may be a layer made of metal and / or metal oxide. Examples of the metal include aluminum, silicon, magnesium, palladium, zinc, tin, nickel, silver, copper, gold, indium, stainless steel, chromium, and titanium. Examples of the metal oxide include aluminum oxide, zinc oxide, antimony oxide, indium oxide, calcium oxide, cadmium oxide, silver oxide, gold oxide, chromium oxide, silicon oxide, cobalt oxide, zirconium oxide, tin oxide, titanium oxide, Examples thereof include iron oxide, copper oxide, nickel oxide, platinum oxide, palladium oxide, bismuth oxide, magnesium oxide, manganese oxide, molybdenum oxide, vanadium oxide, and barium oxide. These metals and metal oxides can be used alone or in combination. Among them, indium is excellent because it has excellent luster, and thus has excellent design properties, and it is preferable because the gloss is not easily lost when a laminated film obtained by laminating a metal layer on the film of the present invention by vapor deposition or the like is deeply drawn. Aluminum is excellent in luster, has excellent design properties, and can be obtained industrially at a low price, and therefore is preferable for applications that do not require deep drawing. As a method of forming a layer made of a metal and / or metal oxide, a vacuum deposition method is usually used, but a method such as ion plating, sputtering, and CVD (Chemical Vapor Deposition) may be used. Good. Before forming a layer made of metal and / or metal oxide, the film of the present invention may be subjected to surface treatment such as corona treatment. The thickness of the layer made of metal and / or metal oxide is generally about 5 to 100 nm, and preferably 5 to 250 nm when deep drawing is performed after the layer is formed.

The other layer may be a layer made of another thermoplastic resin. Other thermoplastic resins suitable for lamination include polycarbonate resin, polyethylene terephthalate resin, polyamide resin, polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, other (meth) acrylic resins, ABS (acrylonitrile-butadiene- Styrene copolymer) resin, ethylene vinyl alcohol resin, polyvinyl butyral resin, polyvinyl acetal resin, styrene thermoplastic elastomer, olefin thermoplastic elastomer, acrylic thermoplastic elastomer, and the like. The thickness of the layer made of these thermoplastic resins is appropriately designed depending on the application and is not particularly limited, and is preferably 500 μm or less from the viewpoint of secondary workability.
The method for producing a laminated film having a layer made of another thermoplastic resin is not particularly limited. For example, (1) A method of laminating separately prepared films of the present invention and other thermoplastic resin films between a pair of heating rolls; (2) Separately prepared films of the present invention and others (3) A film of the present invention and another thermoplastic resin film are prepared separately, and one film is formed by pressure forming or vacuum forming at the same time as the other. (4) Method of laminating separately prepared film of the present invention and another thermoplastic resin film through an adhesive layer (wet lamination method); (5) Book prepared in advance A method of laminating another thermoplastic resin melt-extruded from a T-die on the film of the invention; (6) co-combining the methacrylic resin composition of the present invention with another thermoplastic resin; And the like methods of out molding.

"Laminated molded body"
The laminated molded body of the present invention is obtained by laminating the above-described film of the present invention or the above-described laminated film of the present invention on a substrate. It does not restrict | limit especially as a base material, Other thermoplastic resin base materials, a thermosetting resin base material, a wooden base material, a non-woody fiber base material, etc. are mentioned. The illustration of the other thermoplastic resin used for a base material is the same as that of what was mentioned above as a material of the other layer which comprises a laminated | multilayer film. Examples of other thermosetting resins used for the substrate include epoxy resins, phenol resins, and melamine resins.
The method for producing the laminated molded body is not particularly limited. For example, a laminated molded body can be obtained by subjecting the (laminate) film of the present invention to vacuum heating, pressure molding, compression molding or the like under heating through an adhesive layer as necessary on the substrate. it can.
As another manufacturing method, the (laminated) film of the present invention is inserted between male and female molds for injection molding, and a molten thermoplastic resin is injected into one side of the (laminated) film in this mold. Also preferred is an injection molding simultaneous laminating method in which the formation of an injection molded body and the injection molded body and (laminate) film are simultaneously bonded. The (laminated) film of the present invention used in this method may be a flat film, or may be preformed by vacuum forming, pressure forming, etc. and shaped into an arbitrary uneven shape. Good. In addition, the preforming of the (laminated) film of the present invention may be performed in a mold of an injection molding machine used in the simultaneous injection molding method, or may be performed using another molding machine. A method of injecting a molten resin on one side after preforming a (laminate) film is called an insert molding method.
In the laminated molded body of the present invention, it is preferable that the layer made of the film of the present invention be the outermost layer. The laminated molded body of the present invention is excellent in surface smoothness, surface hardness, surface gloss, and the like. When the laminated film of the present invention has a printed layer, a pattern or the like is clearly displayed. Moreover, when the laminated film which has a layer which consists of a metal or a metal oxide is used, mirror surface glossiness equivalent to a metal is obtained.

As described above, according to the present invention, it is possible to provide a methacrylic resin composition capable of obtaining a molded article having good high temperature moldability and high dimensional stability against heat. Even if the methacrylic resin composition of the present invention is exposed to a higher temperature than before or has a heat history of, for example, about 280 ° C. when passing through a polymer filter, for example, it has good moldability. It can cope with complications. Moreover, the obtained molded object can have high dimensional stability also with respect to a heat | fever about 130 degreeC.
According to the present invention, a methacrylic resin composition capable of obtaining a molded article having good high-temperature moldability and excellent in transparency, dimensional stability against heat, and mechanical strength (impact resistance, toughness, etc.) Things can be provided.

Examples of the present invention and comparative examples will be described below.
[Evaluation items and methods]
Evaluation items and evaluation methods are as follows.
(Polymerization conversion)
A gas chromatograph GC-14A manufactured by Shimadzu Corporation was used as a column and 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))
A sample solution was prepared by dissolving 4 mg of the resin to be measured in 5 ml of tetrahydrofuran (THF) and filtering it with a filter having a pore size of 0.1 μm. As the GPC apparatus, “HLC-8320” manufactured by Tosoh Corporation equipped with a differential refractive index detector (RI detector) was used. As the column, a column in which two “TSKgel Super Multipore HZM-M” manufactured by Tosoh Corporation and “Super HZ4000” were connected in series was used. Tetrahydrofuran (THF) was used as the eluent. The column oven temperature was set at 40 ° C., 20 μl of sample solution was injected into the apparatus at an eluent flow rate of 0.35 ml / min, and the chromatogram was measured. The chromatogram is a chart in which the electric signal value (intensity Y) derived from the difference in refractive index between the sample solution and the reference solution is plotted against the retention time X.
GPC measurement was performed using 10 standard polystyrenes having a molecular weight in the range of 400 to 5000000, and a calibration curve showing the relationship between retention time and molecular weight was created. Based on this calibration curve, Mw and Mw / Mn of the measurement target resin were determined. The baseline of the chromatogram is 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 has the earlier retention time. From the point of view, the point that changes from minus to zero is taken as a connecting line. If the chromatogram shows multiple peaks, connect the line connecting the point where the slope of the highest molecular weight peak changes from zero to positive and the point where the slope of the lowest molecular weight peak changes from negative to zero. Baseline.

(Syndiotacticity (rr) in triplet display)
¹ H-NMR measurement was performed on the resin to be measured. As a measuring apparatus, a nuclear magnetic resonance apparatus (“ULTRA SHIELD 400 PLUS” manufactured by Bruker) was used. 1 mL of deuterated chloroform was used as a deuterated solvent for 10 mg of the sample. The measurement temperature was room temperature (20 to 25 ° C.), and the number of integration was 64 times. 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 0 ppm are measured, and the formula: (X / The value calculated by Y) × 100 was defined as syndiotacticity (rr) (%) in triplet display.

(Dynamic viscoelasticity measurement)
A strip-shaped test piece having a width of 5 mm was cut out from a hot-press molded film having a thickness of 1 mm, and dynamic viscoelasticity measurement was performed. As a measuring device, a forced vibration type dynamic viscoelasticity measuring device (“Rheogel-E4000” manufactured by UBM Co., Ltd.) was used. The test piece was set in the apparatus with a distance between chucks of 20 mm. Fundamental frequency: 1 Hz, measurement mode: tensile mode, strain control: 5 μm, strain waveform: sine wave, static load control: automatic temperature increase from 50 ° C. to 230 ° C. at a rate of 3 ° C./min The temperature dependence was measured. The storage elastic modulus (E ′), loss elastic modulus (E ″), and tan δ were plotted, and the peak of tan δ appearing from 100 ° C. to 180 ° C. was defined as an α relaxation peak. This α relaxation peak top temperature was defined as an α relaxation temperature.

(Melt flow rate (MFR))
Based on JIS K7210, MFR of measurement object resin was measured on condition of 230 degreeC, 3.8kg load, and 10 minutes.
(Melt viscosity η)
After the measurement target resin was dried at 80 ° C. for 12 hours, melt viscosity η was measured using “Capillograph 1D” manufactured by Toyo Seiki Co., Ltd. under the conditions of 260 ° C. and shear rate of 122 sec ⁻¹ .

(High temperature formability (thermal weight retention))
As a measuring device, a thermogravimetric measuring device (“TGA-50” manufactured by Shimadzu Corporation) was used. Under an air atmosphere, the temperature was increased from 50 ° C. to 290 ° C. at a rate of temperature increase of 20 ° C./min, and then the thermal weight reduction of the measurement target resin was measured with a temperature profile held at 290 ° C. for 20 minutes. Using the weight at the time of 50 ° C. as a reference (retention rate 100%), the weight retention after holding at 290 ° C. for 20 minutes was determined, and the high temperature moldability (heat decomposition resistance) was evaluated according to the following criteria. It can be said that the higher the thermal weight retention, the higher the thermal decomposition resistance and the better the high temperature moldability.
<Criteria>
A (good): thermal weight retention is 80% or more,
B (defect): Thermal weight retention is less than 80%.

(Haze)
Based on JIS K7136, the haze of the biaxially stretched film was measured using a haze meter (manufactured by Murakami Color Research Laboratory, HM-150).
(Total light transmittance)
The total light transmittance of the biaxially stretched film was measured using a haze meter (manufactured by Murakami Color Research Laboratory, HM-150) in accordance with JIS K7361-1.

(Dimensional stability (linear thermal expansion coefficient))
A test piece having a width of 4 mm, a length of 20 mm, and a thickness of 40 μm was cut out from the biaxially stretched film. As a measuring device, thermomechanical analysis TMA (“Q400EM” manufactured by TA Instruments) was used. Under conditions of a distance between chucks of 8 mm and a load of 0.01 N, the temperature was raised from 25 ° C. to 130 ° C. at a heating rate of 10 ° C./min, and the dimensional change of the test piece was measured. The linear thermal expansion coefficient was calculated from the slope of the dimensional change in the temperature range of 50 to 90 ° C.

(Shock resistance (shock resistance value))
A test piece of 80 mm × 80 mm × thickness 40 μm was cut out from the biaxially stretched film. Using a film impact tester (manufactured by Yasuda Seiki Co., Ltd.), the impact resistance value when the test piece was broken with a sphere having a diameter of 12.7 ± 0.2 mmφ was measured.

(Thickness direction retardation (Rth))
A test piece of 40 mm × 30 mm was cut out from the obtained biaxially stretched film. This test piece was set in an automatic birefringence meter (“KOBRA-WR” manufactured by Oji Scientific Co., Ltd.). The phase difference in the 40 ° tilt direction was measured under conditions of a temperature of 23 ± 2 ° C., a humidity of 50 ± 5%, and a measurement light wavelength of 590 nm. Refractive indices n _x the value from the average refractive index n, to calculate the n _y, n _z, was calculated thickness direction retardation _{Rth (= ((n x +} n y) / 2-n z) × d) . Incidentally, n _x is the in-plane slow axis direction of the refractive index, n _y in-plane slow axis orthogonal direction refractive index, n _z is the thickness direction of the refractive index, the thickness of d is the test piece [nm] is there. The thickness d [nm] of the test piece was measured using a digimatic indicator (manufactured by Mitutoyo Corporation). The average refractive index n was measured using a digital precision refractometer (“KPR-20” manufactured by Kalnew Optical Industry Co., Ltd.).

(Production Example 1) (Production of methacrylic resin (M1-1))
The inside of the autoclave equipped with a stirring blade and a three-way cock was replaced with nitrogen. To this, 1600 kg of toluene, 80 kg of 1,2-dimethoxyethane, and 73.3 kg of a toluene solution of isobutylbis (2,6-di-t-butyl-4-methylphenoxy) aluminum having a concentration of 0.45 M at room temperature ( 42.3 mol), and a solution of 1.3-M sec-butyllithium (solvent: cyclohexane 95 mass% / n-hexane 5 mass%) 8.44 kg (14.1 mmol) were charged. While stirring, 550 kg of distilled MMA was added dropwise at 15 ° C. over 30 minutes. After completion of dropping, the mixture was stirred at 15 ° C. for 90 minutes. The color of the solution changed from yellow to colorless. At this time, the polymerization conversion of MMA was 100%. The resulting solution was diluted by adding 1500 kg of toluene. Next, the diluted solution was poured into a large amount of methanol to obtain a precipitate. The resulting precipitate was dried at 80 ° C. and 140 Pa for 24 hours to obtain a methacrylic resin (M1-1).
The methacrylic resin (M1-1) has an Mw of 70000, a melt viscosity η of 1200 Pa · s, an Mw / Mn of 1.06, a syndiotacticity (rr) of 75%, and an α relaxation temperature of 142 ° C. The content of the MMA monomer unit was 100% by mass (polymethyl methacrylate (PMMA)). Table 1 shows the physical properties of the methacrylic resin (M1-1).

(Production Example 2) (Production of methacrylic resin (M1-2))
The inside of the autoclave equipped with a stirring blade and a three-way cock was replaced with nitrogen. At room temperature, 13.3 kg of toluene, 60 kg of 1,2-dimethoxyethane, 73.3 kg of a toluene solution of isobutylbis (2,6-di-t-butyl-4-methylphenoxy) aluminum having a concentration of 0.45 M ( 42.3 mol) and a solution of 1.3 M sec-butyllithium (solvent: cyclohexane 95 mass% / n-hexane 5 mass%) 4.22 kg (7.1 mmol) was charged. While stirring, 550 kg of distilled MMA was added dropwise at 15 ° C. over 30 minutes. After completion of dropping, the mixture was stirred at 15 ° C. for 90 minutes. The color of the solution changed from yellow to colorless. At this time, the polymerization conversion of MMA was 100%. The resulting solution was diluted by adding 1500 kg of toluene. Next, the diluted solution was poured into a large amount of methanol to obtain a precipitate. The obtained precipitate was dried at 80 ° C. and 140 Pa for 24 hours to obtain a methacrylic resin (M1-2).
The methacrylic resin (M1-2) has an Mw of 36000, a melt viscosity η of 400 Pa · s, an Mw / Mn of 1.07, a syndiotacticity (rr) of 75%, and an α relaxation temperature of 138 ° C. The content of the MMA monomer unit was 100% by mass (polymethyl methacrylate (PMMA)). Table 1 shows the physical properties of the methacrylic resin (M1-2).

(Production Example 3) (Production of methacrylic resin (M2-1))
The inside of the autoclave equipped with the stirrer and the sampling tube was replaced with nitrogen. To this, 100 parts by mass of purified MMA, 0.0054 parts by mass of 2,2′-azobis (2-methylpropionitrile (hydrogen abstraction capacity: 1%, 1 hour half-life temperature: 83 ° C.), and n-octyl Mercaptan (0.200 parts by mass) was added and stirred to obtain a raw material liquid, and nitrogen was fed into the raw material liquid to remove dissolved oxygen.
The raw material liquid was put in a tank reactor connected to the autoclave by piping up to 2/3 of the capacity. While maintaining the temperature at 140 ° C., the polymerization reaction was first started by a batch method. When the polymerization conversion rate reached 55% by mass, the raw material liquid was supplied from the autoclave to the tank reactor at a flow rate of an average residence time of 150 minutes while maintaining the temperature at 140 ° C., and at the same time, equivalent to the supply flow rate of the raw material liquid The reaction solution was withdrawn from the tank reactor at a flow rate to switch to a continuous flow polymerization reaction. After switching, the polymerization conversion in the steady state was 48% by mass.
The reaction liquid withdrawn from the tank reactor in a steady state was heated by supplying it to a multi-tubular 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 were removed was supplied to a twin-screw extruder having an internal temperature of 260 ° C., discharged in a strand shape, and cut with a pelletizer to obtain a pellet-shaped methacrylic resin (M2-1).
The methacrylic resin (M2-1) has an Mw of 112,000, a melt viscosity η of 1000 Pa · s, an Mw / Mn of 1.86, a syndiotacticity (rr) of 52%, and an α relaxation temperature of 129 ° C. The content of the MMA monomer unit was 100% by mass (polymethyl methacrylate (PMMA)). Table 1 shows the physical properties of the methacrylic resin (M2-1).

(Production Example 4) (Production of methacrylic resin (M2-2))
The inside of the autoclave equipped with the stirrer and the sampling tube was replaced with nitrogen. To this, 100 parts by mass of purified MMA, 0.0065 parts by mass of 2,2′-azobis (2-methylpropionitrile (hydrogen abstraction ability: 1%, 1 hour half-life temperature: 83 ° C.), and n-octyl Mercaptan (0.290 parts by mass) was added and stirred to obtain a raw material liquid, and nitrogen was fed into the raw material liquid to remove dissolved oxygen.
The raw material liquid was put to 2/3 of the capacity in a tank reactor connected to the autoclave by piping. While maintaining the temperature at 120 ° C., the polymerization reaction was first started in a batch mode. When the polymerization conversion rate reached 55% by mass, the raw material liquid was supplied from the autoclave to the tank reactor at a flow rate of 120 minutes while maintaining the temperature at 120 ° C., and at the same time, equivalent to the supply flow rate of the raw material liquid The reaction solution was withdrawn from the tank reactor at a flow rate to switch to a continuous flow polymerization reaction. After switching, the polymerization conversion in the steady state was 45% by mass.
The reaction liquid withdrawn from the tank reactor in a steady state was heated by supplying it to a multi-tubular 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 were removed was supplied to a twin-screw extruder having an internal temperature of 230 ° C., discharged into a strand, and cut with a pelletizer to obtain a pellet-like methacrylic resin (M2-2).
The methacrylic resin (M2-2) has an Mw of 83,000, a melt viscosity η of 700 Pa · s, an Mw / Mn of 1.87, a syndiotacticity (rr) of 55%, and an α relaxation temperature of 130 ° C. The content of the MMA monomer unit was 100% by mass (polymethyl methacrylate (PMMA)). Table 1 shows the physical properties of the methacrylic resin (M2-2).

(Polycarbonate resin (PC))
The following polycarbonate resin (PC) was prepared.
(PC-1): Linear polycarbonate resin (“SD POLYCA TR-2201” manufactured by Sumika Stylon Polycarbonate Co., Ltd.), MVR (measured in accordance with JIS K7210 at 300 ° C., load 1.2 Kg, 10 minutes) = 210 cm ^3/10 min, Mw = 22000, Mw / Mn = 2.0).

(Production Example 5) (Production of crosslinked rubber particle composition (CD-1))
<Production Example 5-1>
48 kg of ion-exchanged water is charged into a 100-liter reaction tank equipped with a condenser, thermometer, and stirrer, and then charged with 416 g of sodium stearate, 128 g of sodium lauryl sarcosinate, and 16 g of sodium carbonate. And dissolved. Next, 11.2 kg of MMA and 110 g of allyl methacrylate were added, and the temperature was raised to 70 ° C. while stirring. Thereafter, 560 g of a 2% aqueous potassium persulfate solution was added to initiate emulsion polymerization. The internal temperature increased due to heat generated by the polymerization, and then the internal temperature began to decrease. After dropping to 70 ° C., the mixture was stirred at 70 ° C. for 30 minutes for emulsion polymerization to obtain an emulsion containing seed particles.
To the emulsion containing seed particles, 720 g of a 2% aqueous sodium persulfate solution was added. Thereafter, a mixture of 12.4 kg of butyl acrylate, 1.76 kg of styrene, and 280 g of allyl methacrylate was dropped over 60 minutes. After completion of dropping, the mixture was stirred for 60 minutes for emulsion polymerization to obtain an emulsion containing core-shell bilayer particles.
To the emulsion containing the core-shell bilayer particles, 320 g of a 2% potassium persulfate aqueous solution was added, and a mixture consisting of 6.2 kg of MMA, 0.2 kg of methyl acrylate, and 200 g of n-octyl mercaptan was added over 30 minutes. After completion of the addition, the mixture was stirred for 60 minutes for emulsion polymerization, and then cooled to room temperature. As described above, an emulsion containing 40% by mass of crosslinked rubber particles (acrylic three-layer polymer particles) (CR-1) having a core-shell three-layer structure having a volume-based average particle size of 0.23 μm was obtained.

<Production Example 5-2>
48 kg of ion-exchanged water is introduced into a 100-liter reaction tank equipped with a condenser, thermometer, and stirrer, and then 252 g of a surfactant (“PEREX SS-H” manufactured by Kao Corporation) is introduced. And dissolved. After raising the temperature of the reaction vessel to 70 ° C., 160 g of 2% potassium persulfate aqueous solution was added thereto, and then a mixture of MMA 3.04 kg, methyl acrylate 0.16 kg, and n-octyl mercaptan 15.2 g was batched. Addition to initiate emulsion polymerization. Stirring was continued for 30 minutes after the exotherm due to the polymerization reaction disappeared.
To this was added 160 g of 2% aqueous potassium persulfate solution, and then a mixture consisting of 27.4 kg of MMA, 1.44 kg of methyl acrylate, and 98 g of n-octyl mercaptan was continuously added dropwise over 2 hours. After completion of dropping, the mixture was stirred for 60 minutes for emulsion polymerization. The resulting emulsion was cooled to room temperature. As described above, an emulsion containing 40% by mass of acrylic polymer particles (dispersion auxiliary particles) (DA-1) having a volume-based average particle size of 0.12 μm and an intrinsic viscosity of 0.44 g / dl was obtained.

<Production Example 5-3>
An emulsion containing the crosslinked rubber particles (acrylic three-layer polymer particles) (CR-1) obtained in Production Example 5-1, and the acrylic polymer particles (dispersion aid particles) obtained in Production Example 5-2 The emulsion containing (DA-1) was mixed so that the mass ratio of particles (CR-1): particles (DA-1) was 2: 1. This mixed emulsion was frozen at −20 ° C. for 2 hours. The frozen mixed emulsion was thrown into 80 ° C. hot water twice as much as that to cause ice melting to obtain a slurry. The slurry was kept at 80 ° C. for 20 minutes, then dehydrated and dried at 70 ° C. to be powdered. As described above, a crosslinked rubber particle composition (CD-1) containing the crosslinked rubber particles (CR-1) and the dispersion auxiliary particles (DA-1) was obtained.

(Production Example 6) (Production of block copolymer (BP-1))
In a three-necked flask purged with nitrogen, 735 kg of dry toluene, 36.75 kg of 1,2-dimethoxyethane, isobutyl bis (2,6-di-t-butyl-) at room temperature (20 to 25 ° C.) 4-methylphenoxy) aluminum 20 mol toluene solution 39.4 kg was added. To this was added 1.17 mol of sec-butyllithium. Further, 39.0 kg of MMA was added and reacted at room temperature for 1 hour to obtain an MMA polymer (methacrylic ester polymer) (b1-1). The Mw of the MMA polymer (b1-1) was 45800.
Next, the reaction solution was cooled to −25 ° C., and a mixed solution of 29.0 kg of n-butyl acrylate and 10.0 kg of benzyl acrylate was added dropwise over 0.5 hour to obtain an MMA polymer (b1-1). The polymerization reaction was continued from the end of the polymer. Thereafter, 4 kg of methanol was added to the reaction solution to stop the polymerization reaction, and the reaction solution was poured into a large amount of methanol to precipitate a block copolymer (BP-1). The resulting precipitate was filtered off and dried at 80 ° C. and 1 torr (about 133 Pa) for 12 hours.
As described above, a diblock copolymer (b1-1) comprising a MMA polymer block (b1-1) and an acrylate polymer block (b2-1) comprising an n-butyl acrylate unit and a benzyl acrylate unit ( BP-1) was obtained. The block copolymer (BP-1) had Mw of 92000 and Mw / Mn of 1.06. Since the Mw of the MMA 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) was 25.6% by mass. The mass ratio of (b1-1) / (b2-1) was 50/50.

(Ultraviolet absorber (LA))
The following ultraviolet absorber (LA) was prepared.
(LA-31): 2,2′-methylenebis [6- (2H-benzotriazol-2-yl) -4-t-octylphenol] (manufactured by ADEKA),
(LA-F70): 2,4,6-tris (2-hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine (manufactured by ADEKA).

(Polymer processing aid (PA))
The following polymer processing aid (PA) was prepared.
(PA-1): “Metabrene P550A” manufactured by Mitsubishi Rayon Co., Ltd. (average polymerization degree: 7734, MMA monomer unit content: 88 mass%, butyl acrylate monomer unit content: 12 mass%).

(Example 1)
20 parts by weight of methacrylic resin (M1-1), 80 parts by weight of methacrylic resin (M2-1), 1.0 part by weight of block copolymer (BP-1), 0.9 part by weight of UV absorber (LA-F70) And 2 parts by mass of polymer processing aid (PA-1) are mixed and melt kneaded at 250 ° C. using a twin-screw extruder (“KZW20TW-45MG-NH-600” manufactured by Technobel Co., Ltd.). The melt-kneaded product was extruded to produce a methacrylic resin composition (R11). The physical properties of the methacrylic resin composition (R11) were evaluated. Table 2 shows the composition and evaluation results of the methacrylic resin composition (R11).
The obtained methacrylic resin composition (R11) was dried at 80 ° C. for 12 hours. Using a 20 mmφ single screw extruder (OCS), the methacrylic resin composition (R11) was extruded from a 150 mm wide T-die at a resin temperature of 260 ° C., and taken up with a roll having a surface temperature of 100 ° C. An unstretched film having a thickness of 160 μm was obtained.
The obtained unstretched film was cut out to 100 mm × 100 mm. Biaxial stretching was performed on this film using a two-tank batch biaxial stretching tester. In the first tank, simultaneous biaxial stretching was performed under the conditions of a stretching temperature Tg + 20 ° C., a stretching speed of 860% / min, and a stretching ratio of 2 × 2, and then in the second tank, a heat setting temperature Tg−10 ° C. for 90 seconds. After heat setting under the conditions, the film was quenched and a biaxially stretched film (F11) having a thickness of 40 μm was obtained. Table 3 shows the stretching conditions and the evaluation results of the biaxially stretched film. Furthermore, one side of the obtained biaxially stretched film (F11) was subjected to corona discharge treatment, and then aluminum was deposited to a thickness of 30 nm by a vacuum deposition method. The laminated film thus obtained was excellent in specular gloss.

(Examples 2 to 4)
In each of Examples 2 to 4, methacrylic resin compositions (R12) to (R14) and biaxially stretched films (F12) to (F14) were obtained in the same manner as in Example 1 except that the composition and stretching conditions were changed. ) And evaluated. Tables 2 and 3 show the composition, stretching conditions and evaluation results.
(Comparative Examples 1 to 4)
In each of Comparative Examples 1 to 4, methacrylic resin compositions (R21) to (R24) and biaxially stretched films (F21) to (F24) were obtained in the same manner as in Example 1 except that the composition and stretching conditions were changed. ) And evaluated. Tables 2 and 3 show the composition, stretching conditions and evaluation results.

(result)
Examples 1 to 4 include a methacrylic resin (M1) having an α relaxation temperature of 137 ° C. or higher and a methacrylic resin (M2) having an α relaxation temperature of 132 ° C. or lower, and a melt viscosity η of the methacrylic resin (M1). Methacrylic resin compositions (R11) to (R14) in which ₁ is greater than the melt viscosity η _{2 of the} methacrylic resin (M2) and the weight ratio of methacrylic resin (M1) / methacrylic resin (M2) is 2/98 to 29/71. ) Was manufactured. All of the methacrylic resin compositions (R11) to (R14) obtained in Examples 1 to 4 had a high thermogravimetric retention and good high temperature moldability. Each of the biaxially stretched films (F11) to (F14) obtained in Examples 1 to 4 had high transparency, a small coefficient of linear thermal expansion, good dimensional stability, and good impact resistance. .

In Comparative Example 1 in which only the methacrylic resin (M2) was used as the methacrylic resin, the obtained biaxially stretched film (F21) had a large linear thermal expansion coefficient, poor dimensional stability, and poor impact resistance. It was. In Comparative Examples 2 and 3 in which a methacrylic resin (M1) and a methacrylic resin (M2) were used in combination as the methacrylic resin, the amount of the methacrylic resin (M1) was larger than those in Examples 1 to 3, the obtained methacrylic resin All of the compositions (R22) to (R23) had a low thermogravimetric retention and poor high temperature moldability. In Comparative Example 4 where the melt viscosity η ₁ of the methacrylic resin (M1) is smaller than the melt viscosity η ₂ of the methacrylic resin (M2), the linear expansion coefficient is large, so that the dimensional stability is poor and the impact resistance is also poor.

The present invention is not limited to the above-described embodiments and examples, and design changes can be made as appropriate without departing from the spirit of the present invention.

This application claims priority based on Japanese Patent Application No. 2016-150205 filed on July 29, 2016, the entire disclosure of which is incorporated herein.

Claims

A methacrylic resin (M1) having an α relaxation temperature T α1 of 137 ° C. or higher when measured in a tensile mode and dynamic viscoelasticity at 1 Hz;
A tensile mode, a methacrylic resin composition with a methacrylic resin (M2) having an α relaxation temperature Tα2 of 132 ° C. or lower when dynamic viscoelasticity is measured at 1 Hz,
When the melt viscosity of the methacrylic resin (M1) and the methacrylic resin (M2) at 260 ° C. and a shear rate of 122 sec −1 is η 1 and η 2 , respectively, η 1 > η 2
A methacrylic resin composition having a methacrylic resin (M1) / methacrylic resin (M2) mass ratio of 2/98 to 29/71.
The methacrylic resin composition according to claim 1, wherein the molecular weight distribution of the methacrylic resin (M1) is 1.0 to 1.4.
The methacrylic resin composition according to claim 1 or 2, wherein the methacrylic resin (M1) has a weight average molecular weight of 40,000 to 200,000.
The methacrylic resin composition according to any one of claims 1 to 3, wherein the content of the methyl methacrylate monomer unit in the methacrylic resin (M2) is 99% by mass or more.
The methacrylic resin composition according to any one of claims 1 to 4, further comprising a polycarbonate resin and / or a phenoxy resin.
The methacrylic resin composition according to any one of claims 1 to 5, further comprising a crosslinked rubber and / or a block copolymer.
The methacrylic resin composition according to any one of claims 1 to 6, further comprising an ultraviolet absorber.
When the melt viscosity of the methacrylic resin (M1) and the methacrylic resin (M2) at 260 ° C. and a shear rate of 122 sec −1 is η 1 and η 2 , η 1 > η 2
A methacrylic resin (M1) having an α relaxation temperature T α1 of 137 ° C. or higher when measured in a tensile mode and dynamic viscoelasticity at 1 Hz;
A methacrylic resin (M2) having an α relaxation temperature T α2 of 132 ° C. or lower when a dynamic viscoelasticity measurement is performed at a tensile mode of 1 Hz.
A method for producing a methacrylic resin composition, comprising melt-kneading a methacrylic resin (M1) / methacrylic resin (M2) in a mass ratio of 2/98 to 29/71.
A molded body comprising the methacrylic resin composition according to any one of claims 1 to 7.
A film comprising the methacrylic resin composition according to any one of claims 1 to 7.
The film according to claim 10, which is a stretched film.
A laminated film having a layer comprising the film according to claim 10 or 11.
The laminated film according to claim 12, further comprising a layer made of a metal and / or a metal oxide.
The laminated film according to claim 12 or 13, further comprising an adhesive layer.
15. A laminated molded body in which the laminated film according to any one of claims 12 to 14 is laminated on a substrate.