JP5186415B2 - Methacrylic resin film - Google Patents

Description

  The present invention relates to a methacrylic resin film. More specifically, the present invention relates to a methacrylic resin film having excellent transparency, toughness, and surface smoothness, high surface hardness, hot water whitening resistance, and excellent appearance (low roughness).

The methacrylic resin film is excellent in transparency and has a beautiful appearance and weather resistance. However, methacrylic resin films are fragile and have poor flexibility or toughness, so their use range is limited.
As a method for improving the toughness of a methacrylic resin, a method of blending a multilayer structure acrylic rubber particle produced by an emulsion polymerization method with a methacrylic resin is disclosed (Patent Document 1 and Patent Document 2). This method is currently the most widely implemented industrially. This multilayer structure acrylic rubber particle is composed of two or more layers, and a hard layer mainly composed of methyl methacrylate and a soft layer mainly composed of an acrylate ester such as n-butyl acrylate are substantially And have a spherical structure that overlaps alternately. However, the methacrylic resin film obtained by this method is liable to generate lumps (fish eyes) due to lumps (gel colonies) generated by aggregation of the acrylic rubber particles of the multilayer structure, and the appearance of the film is easily impaired. Further, the film is likely to be whitened by water absorption by the emulsifier used in the emulsion polymerization method and when the temperature rises after rain when immersed in warm water or outdoors. For this reason, there is a limit to use for optical films that require high transparency.

  Further, as another method for improving the toughness of methacrylic resin, a method of polymerizing a monomer mainly composed of methyl methacrylate in the presence of butadiene-n-butyl acrylate copolymer rubber (Patent Document 3). And a method of polymerizing a monomer mainly composed of methyl methacrylate in the presence of a partially hydrogenated conjugated diene polymer rubber (Patent Document 4). However, in these methods, it is difficult to control the dispersibility of the rubber component, and it may still cause poor appearance.

  Patent Document 5 proposes a composition obtained by blending a methacrylic resin with a block copolymer obtained by grafting a methyl methacrylate copolymer and a vinyl acetate copolymer. However, this composition has low transparency and is not suitable for a transparent film.

JP-A 64-66221 Japanese Patent Laid-Open No. 03-237134 Japanese Examined Patent Publication No. 45-26111 WO96 / 032440 Japanese Patent Laid-Open No. 06-345933

  An object of the present invention is to provide a methacrylic resin film having excellent transparency, toughness, surface smoothness, high surface hardness, hot water whitening resistance and excellent appearance (low roughness), and a laminate using the same. There is to do.

  As a result of intensive investigations to achieve the above object, the present inventors have found that 100 parts by mass of a continuous phase composed of a methacrylic resin (A) having a repeating unit derived from methyl methacrylate of 50% by mass or more ( 30 to 65% by mass of the polymer block (a) having a glass transition temperature of 23 ° C. or less and a repeating unit derived from a conjugated diene compound is 0 ° C. When a film is formed using a methacrylic resin composition containing 1 to 80 parts by mass of a block copolymer (B) having a polymer block (b) of 35 to 70% by mass as a dispersed phase, the transparency is as follows. A methacrylic resin film having excellent surface smoothness, high surface hardness, hot water whitening resistance, and excellent appearance (low roughness) can be obtained. Heading was. The present invention has been further studied and completed based on this finding.

That is, the present invention is a glass comprising a repeating unit derived from a (meth) acrylic acid alkyl ester in 100 parts by mass of a continuous phase consisting of a methacrylic resin (A) having a repeating unit derived from methyl methacrylate of 50% by mass or more. 30 to 65% by mass of polymer block (a) having a transition temperature of 23 ° C. or less and 35 to 70% by mass of polymer block (b) having a glass transition temperature of 0 ° C. or less consisting of repeating units derived from a conjugated diene compound. It is a methacrylic resin film which has a layer which consists of a methacrylic resin composition which 1-80 mass parts of block copolymers (B) have as a disperse phase.
Moreover, this invention is a laminated body formed by laminating | stacking the said methacrylic resin film on a base material.

  Since the methacrylic resin film of the present invention has a high total light transmittance, it is excellent in visibility even when used for protecting the printed surface. Even if it is further thinned, it has excellent toughness and high surface hardness, so that even when used for automobile interior materials and decorative products, it is difficult to cause defects such as scratches and cracks. In addition, since it has low surface roughness and excellent surface smoothness and surface glossiness, it can be applied to equipment, buildings, vehicles and the like that require design and fashionability.

Hereinafter, the present invention will be described in more detail.
The methacrylic resin film of the present invention has a layer composed of a resin composition containing a block copolymer (B) as a dispersed phase in a continuous phase composed of a methacrylic resin (A).

(Continuous phase)
The methacrylic resin (A) constituting the continuous phase is a resin having 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more of repeating units derived from methyl methacrylate.
As repeating units derived from vinyl monomers other than repeating units derived from methyl methacrylate, alkyl acrylates such as methyl acrylate, ethyl acrylate, butyl acrylate; ethyl methacrylate, butyl methacrylate, etc. Methacrylic acid alkyl esters excluding methyl methacrylate; acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, styrene, α-methylstyrene, etc .; repeating derived from a non-crosslinkable monomer having only one alkenyl group in one molecule Units are listed.
The mass ratio of methyl methacrylate / other vinyl monomer is 50/50 to 100/0, preferably 80/20 to 99/1, more preferably 90/10 to 98/2.

  The weight average molecular weight of the methacrylic resin (A) measured by GPC (gel permeation chromatography) is preferably 70,000 to 200,000, more preferably 80,000 to 150,000, and particularly preferably 90,000 to 120,000. . If the weight average molecular weight is less than 70,000, the toughness and handleability of the methacrylic resin film tend to decrease. If the weight average molecular weight exceeds 200,000, the fluidity of the methacrylic resin composition decreases and film formation becomes difficult. Even if film formation is possible, the surface smoothness of the methacrylic resin film tends to decrease.

  Further, the methacrylic resin (A) used in the present invention has a molecular weight distribution (= weight average molecular weight / number average molecular weight) measured by GPC, preferably 3.0 or less, more preferably 2.5 or less, particularly Preferably it is 2.3 or less. When the molecular weight distribution exceeds 3.0, the toughness and film forming property of the methacrylic resin film tend to be lowered. The molecular weight and molecular weight distribution of the methacrylic resin can be controlled by adjusting the types and amounts of the polymerization initiator and the chain transfer agent.

(Dispersed phase)
The block copolymer (B) contained in the dispersed phase preferably has a glass transition temperature of 23 ° C. or less, more preferably 0 ° C. or less, more preferably − The polymer block (a) having a temperature of 10 ° C. or lower and the polymer block (b) having a glass transition temperature composed of repeating units derived from the conjugated diene compound are preferably 0 ° C. or lower, more preferably −10 ° C. or lower. Is. The lower the glass transition temperature, the more suitable for use in cold regions.

The repeating unit derived from the (meth) acrylic acid alkyl ester constituting the polymer block (a) is obtained by addition polymerization of (meth) acrylic acid alkyl ester. “(Meth) acryl” means methacryl or acrylic.
Examples of the alkyl methacrylate include methyl methacrylate, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate and the like, and examples of the acrylic acid alkyl ester include methyl acrylate, ethyl acrylate, n-butyl acrylate, and acrylic acid. i-butyl, 2-ethylhexyl acrylate, and the like. These may be polymerized individually by 1 type, and may be copolymerized combining 2 or more types. Among these, a monomer or a combination of monomers giving a polymer block (a) having a glass transition temperature (Tg) of 23 ° C. or lower is preferable, and a monomer giving a polymer block (a) having a Tg of 0 ° C. or lower is preferable. A monomer or a combination of monomers is more preferable, and a monomer or a combination of monomers giving a polymer block (a) having a Tg of −10 ° C. or lower is still more preferable. As such a monomer, n-butyl acrylate and / or 2-ethylhexyl acrylate are preferable, and n-butyl acrylate is more preferable.

The repeating unit derived from the conjugated diene compound constituting the polymer block (b) is obtained by addition polymerization of the conjugated diene compound.
Examples of the conjugated diene compound include 1,3-butadiene, isoprene, pentadiene, 2,3-dimethylbutadiene and the like. These may be polymerized individually by 1 type, and may be copolymerized combining 2 or more types. Among these, a monomer or a combination of monomers giving a polymer block (b) having a glass transition temperature (Tg) of 0 ° C. or lower is preferable, and a polymer block (b) having a Tg of −10 ° C. or lower is given. A monomer or a combination of monomers is more preferred. Moreover, 1,3-butadiene and / or isoprene are preferable from the viewpoint of versatility, economy, and handleability, and 1,3-butadiene is more preferable.

  Conjugated diene compounds include those that undergo 1,4-addition polymerization and those that undergo 1,2- or 3,4-addition polymerization. When the conjugated diene compound undergoes 1,4-addition polymerization, it has a carbon-carbon double bond in the molecular main chain. When the conjugated diene compound is subjected to 1,2- or 3,4-addition polymerization, the conjugated diene compound has a vinyl group (side chain vinyl bond) bonded to the molecular main chain. The carbon-carbon double bond and / or the vinyl group bonded to the molecular main chain in the molecular main chain is a starting point for the graft reaction or the crosslinking reaction. The proportion of 1,2- or 3,4-addition polymerization of the conjugated diene compound can be increased by adding a polar compound such as ethers to the reaction system.

The amount of the side chain vinyl bonds in the polymer block (b) is selected in consideration of the graft reactivity with the methacrylic resin as the continuous phase, the crosslinking reactivity of the dispersed phase, and the toughness of the methacrylic resin film. The amount of side chain vinyl bonds in the polymer block (b) is preferably 10 mol% to 60 mol%, more preferably 10 mol% to 50 mol%, and still more preferably 10 mol% to 35 mol%. When the side chain vinyl bond content is in this range, transparency, surface smoothness, toughness, flexibility, and the like are improved. The amount of the side chain vinyl bond is represented by the ratio [mol%] of 1,2-addition polymerization or 3,4-addition polymerization conjugated diene compound in 1 mol of the conjugated diene compound. For example, in the case of a polymer block (b) composed of repeating units derived from 1,3-butadiene, it is analyzed using ¹ H-NMR, and a chemical shift of 4.7 to 5.2 ppm (hereinafter referred to as signal C ₀ ). )) And 1,2-vinyl protons (= CH ₂ ) and chemical shifts of 5.2 to 5.8 ppm (hereinafter referred to as signal D ₀ ) vinyl protons (= CH-), and the integrated intensity is obtained. The side chain vinyl bond amount V ₀ [%] can be calculated and calculated by the equation.
V ₀ = _{[(C 0/2) / {} C 0/2 + (D 0 -C 0/2) / 2} ] × 100

  The polymer block (b) may be obtained by partially hydrogenating a carbon-carbon double bond in the aforementioned molecular main chain and / or a vinyl group bonded to the molecular main chain. From the viewpoint of maintaining the effects of the present invention, the hydrogenation rate of the polymer block (b) is preferably less than 70 mol%, and more preferably less than 50 mol%. The method of hydrogenation is not particularly limited, and can be achieved by, for example, the method disclosed in Japanese Patent Publication No. 5-20442.

The total number average molecular weight (Mn) of the block copolymer (B) used in the present invention is preferably 5,000 to 1,000,000, more preferably from the viewpoint of toughness and handleability of the methacrylic resin film. It is 10,000 to 800,000, particularly preferably 50,000 to 500,000.
The number average molecular weight is a value in terms of polystyrene calculated by gel permeation chromatography (GPC).

  The mass ratio of the polymer block (a) to the polymer block (b) is such that when the total of the polymer block (a) and the polymer block (b) is 100% by mass, the polymer block (a) Is 30 to 65% by mass, preferably 40 to 60% by mass. A polymer block (b) is 35-70 mass%, Preferably it is 40-60 mass%.

The block copolymer (B) may have one each of the polymer block (a) and the polymer block (b), or the polymer block (a) and / or the polymer block (b). ) May be included.
Examples of the bonding mode of the block copolymer include an ab type diblock copolymer, an aba type triblock copolymer, a bb type triblock copolymer, and an aba type. -B-type tetrablock copolymers and linear multi-block copolymers represented by bb-ba type tetrablock copolymers, (ba-) _n , (ab-) _n, etc. And a star-shaped (radial star) block copolymer represented by the formula, a graft copolymer represented by a-g-b, and the like. Note that n is a value larger than 2. g is a bond symbol representing a graft bond. The block copolymer (B) may have an inclined connecting part between the polymer block (a) and the polymer block (b). The inclined connecting portion is a portion having a repeating unit composition that gradually changes from the composition of the repeating unit of the polymer block (a) to the composition of the repeating unit of the polymer block (b). These block copolymers may be used individually by 1 type, and may be used in combination of 2 or more type.

The block copolymer (B) has a refractive index of preferably 1.48 to 1.50, more preferably 1.485 to 1.495. When the refractive index is within this range, the transparency of the methacrylic resin is maintained.
The refractive index of the block copolymer (B) can be adjusted by selecting the kind of repeating unit constituting the polymer, the composition ratio, the amount of side chain vinyl bonds in the polymer block (b), and the like. For example, a diblock copolymer comprising a polymer block (a) composed of repeating units derived from n-butyl acrylate and an unhydrogenated polymer block (b) composed of repeating units derived from 1,3-butadiene. Then, when the content of n-butyl acrylate is 30 to 65% by mass and the content of 1,3-butadiene is 35 to 70% by mass with respect to the total mass of the diblock copolymer, the refractive index of polymethyl methacrylate And a transparent methacrylic resin film can be obtained.

  The block copolymer (B) is a diblock composed of a polymer block composed of repeating units derived from n-butyl acrylate monomers and a polymer block composed of repeating units derived from 1,3-butadiene monomers. Block copolymer, radial star block copolymer, polymer block composed of repeating units derived from 2-ethylhexyl acrylate monomer, and polymer block composed of repeating units derived from 1,3-butadiene monomer A diblock copolymer, a radial star block copolymer, a polymer block composed of repeating units derived from a methyl methacrylate monomer, and a polymer composed of repeating units derived from an n-butyl acrylate monomer A triblock composed of a block and a polymer block composed of repeating units derived from 1,3-butadiene monomer. Lock copolymer or radial star block copolymer.

As the block copolymer (B), a star block copolymer is particularly preferable from the viewpoint of the mechanical strength of the dispersed phase.
The star block copolymer includes a copolymer in which a plurality of arm polymer blocks are linked by a group (coupling agent residue) derived from a polyfunctional monomer, a polyfunctional coupling agent, or the like.

  The arm polymer block constituting the star block copolymer is not limited by the bonding mode as long as it has the polymer block (a) and / or the polymer block (b). As the arm polymer block, an ab type diblock copolymer, an aba type triblock copolymer, a bb type triblock copolymer, an abaa- Examples thereof include a b-type tetrablock copolymer, a multiblock copolymer in which four or more polymer blocks (a) and polymer blocks (b) are bonded. The plurality of arm polymer blocks constituting the star block copolymer may be the same type of block copolymer or may be different types of block copolymers.

In the present invention, the chemical structural formula:
(Polymer block (b) -polymer block (a)-) _n X
A star block copolymer represented by the formula (wherein X represents a coupling agent residue and n represents a number exceeding 2) is particularly preferred.

The star block copolymer has a polystyrene-equivalent number average molecular weight calculated by GPC.
[Number average molecular weight of star block copolymer]> 2 × [Number average molecular weight of arm polymer block]
It is preferable to satisfy.
The ratio of [number average molecular weight of star block copolymer] / [number average molecular weight of arm polymer block] is sometimes referred to as the number of arms.

  A machine for shearing the dispersed phase of the star block copolymer dispersed in the continuous phase by setting the number average molecular weight of the star block copolymer to a range exceeding twice the number average molecular weight of the arm polymer block. The mechanical strength is increased and desired toughness can be obtained. Since the number average molecular weight of the star block copolymer is more than 100 times the number average molecular weight of the arm polymer block is difficult to synthesize, the number average molecular weight of the industrially preferable star block copolymer is: The number average molecular weight of the arm polymer block is more than 2 times and 100 times or less, more preferably 2.5 to 50 times, and further preferably 3 to 10 times.

  The block copolymer (B) preferably used in the present invention is mainly composed of a star-shaped block copolymer, but other than this, an arm polymer not linked by a coupling agent residue. Blocks may be included. The mass ratio of the star block copolymer / arm polymer block not linked by the coupling agent residue is preferably 20/80 or more, and more preferably 30/70 or more.

A block copolymer (B) is not specifically limited by the manufacturing method, It can employ | adopt from what was obtained by the method according to a well-known method. In general, as a method for obtaining a block copolymer having a narrow molecular weight distribution, a method of living polymerizing monomers as constituent units is employed.
Living polymerization methods include, for example, a method of polymerizing using an organic rare earth metal complex as a polymerization initiator, an organic alkali metal compound as a polymerization initiator, and in the presence of an alkali metal or alkaline earth metal mineral salt. And an anion polymerization method using an organic alkali metal compound as a polymerization initiator in the presence of an organoaluminum compound, an atom transfer radical polymerization (ATRP) method, and the like.

  Among the above production methods, the method of anionic polymerization using an organoalkali metal compound as a polymerization initiator in the presence of an organoaluminum compound is a narrower molecular weight distribution and a residual monomer under relatively mild temperature conditions. Is preferable in that it can produce a block copolymer with a small amount and has a low environmental load (mainly power consumption of a refrigerator necessary for controlling the polymerization temperature) in industrial production.

As the organic alkali metal compound used for the anionic polymerization, an organic lithium compound is preferable.
Specific examples of the organic lithium compound include methyl lithium, ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, isobutyl lithium, tert-butyl lithium, n-pentyl lithium, and n-hexyl lithium. Alkyllithium and alkyldilithium such as tetramethylenedilithium, pentamethylenedilithium and hexamethylenedilithium; aryllithium and aryldilithium such as phenyllithium, m-tolyllithium, p-tolyllithium, xylyllithium and lithium naphthalene Lithium; benzyl lithium, diphenylmethyl lithium, trityl lithium, 1,1-diphenyl-3-methylpentyl lithium, α-methylstyryl lithium, diisopropenyl benzene Aralkyllithium and aralkyldilithium such as dilithium produced by the reaction of butyllithium with lithium; lithium amides such as lithium dimethylamide, lithium diethylamide and lithium diisopropylamide; methoxylithium, ethoxylithium, n-propoxylithium, isopropoxylithium, n -Butoxylithium, sec-butoxylithium, tert-butoxylithium, pentyloxylithium, hexyloxylithium, heptyloxylithium, octyloxylithium, phenoxylithium, 4-methylphenoxylithium, benzyloxylithium, 4-methylbenzyloxylithium, etc. Lithium alkoxide of the following. These may be used alone or in combination of two or more.

Examples of the organoaluminum compound used in the above anionic polymerization include the following general formula:
AlR ¹ R ² R ³
(In the formula, R ¹ , R ² and R ³ may each independently have an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, or a substituent. A good aryl group, an aralkyl group which may have a substituent, an alkoxyl group which may have a substituent, an aryloxy group which may have a substituent or an N, N-disubstituted amino group; Or R ¹ represents any of the groups described above, and R ² and R ³ together represent an aryleneoxy group which may have a substituent.) Is mentioned.
Among these organoaluminum compounds, isobutylbis (2,6-di-tert-butyl-4-methylphenoxy) aluminum, isobutylbis (2,6-di-tert-butylphenoxy) aluminum, isobutyl [2,2′- Methylenebis (4-methyl-6-tert-butylphenoxy)] aluminum is particularly easy in handling and allows the anionic polymerization reaction to proceed without deactivation under relatively mild temperature conditions. preferable.

  In the above anionic polymerization, if necessary, an ether such as dimethyl ether, dimethoxyethane, diethoxyethane, 12-crown-4-ether; triethylamine, N, N, N ′, N′— Including tetramethylethylenediamine, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine, 1,1,4,7,10,10-hexamethyltriethylenetetramine, pyridine, 2,2′-dipyridyl, etc. Nitrogen compounds can further coexist for stabilization of the polymerization reaction.

The star block copolymer can be obtained by adding a polyfunctional monomer to the block copolymer reaction solution obtained by the above-mentioned anionic polymerization or the like and copolymerizing it, or by adding the block copolymer reaction solution to the block copolymer reaction solution. It can be obtained by adding a polyfunctional coupling agent to cause a coupling reaction.
The polyfunctional monomer is a compound having two or more ethylenically unsaturated groups, and specifically includes allyl methacrylate, ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, divinylbenzene, 1 , 6-hexanediol diacrylate and the like.
The polyfunctional coupling agent is a compound having 3 or more reactive groups, specifically, trichloromethylsilane, tetrachlorosilane, butyltrichlorosilane, bis (trichlorosilyl) ethane, tetrachlorotin, butyltrichlorotin, Examples include tetrachlorogermanium.

  The methacrylic resin composition used in the present invention is usually 1 to 80 parts by mass, preferably 2 to 30 parts by mass of the block copolymer (B) with respect to 100 parts by mass of the methacrylic resin (A). More preferably, it contains in 4-20 mass parts. When there are few block copolymers (B), the effect of the toughness improvement of a methacrylic resin film is small. When there are many block copolymers (B), it will become difficult for a block copolymer (B) to form a dispersed phase. Further, the surface hardness and rigidity of the methacrylic resin film tend to decrease. In addition, it is easy to generate lumps and the appearance may be impaired.

  The average diameter of the dispersed phase comprising the block copolymer (B) is usually 0.05 to 1 μm, preferably 0.05 to 0.5 μm, more preferably 0.08 to 0.4 μm. When the average diameter of the dispersed phase is small, the handleability tends to decrease, and when the average diameter of the dispersed phase is large, the transparency and surface smoothness tend to decrease.

  The dispersed phase preferably contains a sea-island structure composed of a sea phase composed of the block copolymer (B) and an island phase composed of the methacrylic resin (A). The sea-island structure of the dispersed phase is obtained by cutting a molded plate of a methacrylic resin composition with a diamond knife to obtain an ultrathin section, staining the section with osmium tetroxide, and observing it with a transmission electron microscope. I can confirm.

In dyeing with osmium tetroxide, the polymer block (b) in the block copolymer (B) is dyed. The dispersed phase of the sea-island structure is composed of a sea phase composed of a dyed portion (block copolymer (B)) and an island phase composed of an undyed portion (methacrylic resin (A)).
The average diameter of the island phase is usually 0.01 to 0.2 μm, preferably 0.05 to 0.1 μm.
The area ratio of the island phase / sea phase observed in the molded plate section is preferably 20/80 or more, more preferably 30/70 to 70/30.
Moreover, it is preferable that the ratio of the dispersed phase which comprised the sea-island structure is 20 mass% or more of all the dispersed phases, and it is more preferable that it is 30-100 mass%.

The methacrylic resin composition used in the present invention is not particularly limited by the production method. For example, it can be obtained by adding the block copolymer (B) constituting the dispersed phase to the methacrylic resin (A) constituting the continuous phase and melt-kneading in a uniaxial or biaxial melt extruder or the like. However, the block copolymer (B) is dissolved in a monomer mixture (A _m ) containing 50% by mass or more of methyl methacrylate, the monomer mixture (A _m ) is polymerized under shear, and polymerization is in progress. It is preferable to obtain by a method in which the solution phase of the polymer of the monomer mixture (A _m ) and the solution phase of the block copolymer (B) are reversed.

In a preferred method for producing the methacrylic resin composition, first, the block copolymer (B) is mixed with 50 to 100% by mass of methyl methacrylate and other vinyl monomers 0 to 50 copolymerizable with methyl methacrylate. A raw material liquid is prepared by dissolving in a monomer mixture (A _m ) composed of mass% and, if necessary, a solvent (C).

The methyl methacrylate and other vinyl monomers copolymerizable with methyl methacrylate used in the monomer mixture (A _m ) are the same as those described above.
The solvent (C) used in the present invention includes a monomer mixture (A _m ), a polymer of the monomer mixture (A _m ) (that is, a methacrylic resin (A)), and a block copolymer (B). As long as it has the ability to dissolve in water, it is not particularly limited. For example, aromatic hydrocarbons such as benzene, toluene, and ethylbenzene are desirable. Moreover, you may mix and use 2 or more types of solvents as needed. When using a mixed solvent, the monomer mixture (A _m), if the mixed solvent can dissolve the methacrylic resin (A) and the block copolymer (B), the monomer mixture (A _m), methacrylic A solvent that cannot dissolve the resin (A) and the block copolymer (B) may be contained in the mixed solvent. For example, the mixed solvent may contain alcohols such as methanol, ethanol and butanol; ketones such as acetone and methyl ethyl ketone; hydrocarbons such as hexane; alicyclic hydrocarbons such as cyclohexane and the like.

The amount of the block copolymer (B) in the raw material liquid is usually 1 to 80 parts by mass, preferably 2 to 30 parts by mass, and more preferably 4 parts per 100 parts by mass of the monomer mixture (A _m ). ˜20 parts by mass. When the amount of the block copolymer (B) is less than 1 part by mass, the effect of improving the toughness of the methacrylic resin film is small. When the amount of the block copolymer (B) is more than 80 parts by mass, the block copolymer (B) is difficult to form a dispersed phase. Further, the elastic modulus of the methacrylic resin film is lowered, and the excellent rigidity inherent in the methacrylic resin is lost.

  Dissolution of the block copolymer (B) is promoted by stirring, and further promoted by heating to about 30 to 60 ° C. Moreover, when preparing a raw material liquid, the said solvent (C) can be used as needed.

The quantity of the solvent (C) in a raw material liquid is 0-100 mass parts normally with respect to 100 mass parts of monomer mixtures ( _Am ), Preferably it is 0-90 mass parts. The larger the amount of the solvent, the lower the viscosity of the raw material liquid and the better the handling properties, but it may cause side reactions such as chain transfer reaction and inhibit graft reaction and cross-linking reaction, and the productivity tends to decrease. .

Next, the raw material liquid is polymerized. Simultaneously with the polymerization of the raw material liquid, the polymerization reaction of the monomer mixture (A _m ) proceeds, and at the same time, the graft reaction and / or crosslinking between the block copolymer (B) and the monomer mixture (A _m ). The reaction proceeds.
For polymerization of the raw material liquid, a radical polymerization initiator is usually used. Moreover, a chain transfer agent is used as needed.

  The polymerization initiator is not particularly limited as long as it generates a reactive radical. As polymerization initiators, azo compounds such as azobisisobutyronitrile and azobiscyclohexylcarbonitrile; benzoyl peroxide, t-butylperoxy 2-ethylhexanoate, t-butylperoxybenzoate, di-t- Butyl peroxide, dicumyl peroxide, 1,1-di (t-butylperoxy) 3,3,5-trimethylcyclohexane, t-butylperoxyisopropyl carbonate, 1,1-di (t-butylperoxy) Examples thereof include organic peroxides such as cyclohexane and t-hexylperoxyisopropyl monocarbonate. These polymerization initiators may be used alone or in combination of two or more. Further, the addition timing and addition method of the polymerization initiator are not particularly limited as long as the predetermined polymerization reaction proceeds, but the pre-stage polymerization is performed with the polymerization initiator charged at the start of the polymerization, and the polymerization is performed in the middle of the reaction. It is preferable to carry out post polymerization by adding an initiator.

  As the chain transfer agent, n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, 1,4-butanedithiol, 1,6-hexanedithiol, ethylene glycol bisthiopropionate, butanediol bisthioglycolate, Alkyl mercaptans such as butanediol bisthiopropionate, hexanediol bisthioglycolate, hexanediol bisthiopropionate, trimethylolpropane tris- (β-thiopropionate), pentaerythritol tetrakisthiopropionate; α-methylstyrene dimer; terpinolene and the like can be mentioned. These can be used alone or in combination of two or more.

In the polymerization of the raw material liquid, it is important to give a shearing force to the raw material liquid from the initial stage of polymerization until phase inversion occurs. At the initial stage of polymerization, the polymerization of the monomer mixture (A _m ) mainly proceeds to produce a methacrylic resin. As the polymerization conversion increases, the proportion of the solution phase of the methacrylic resin produced by the polymerization of the monomer mixture (A _m ) increases, and the solution phase of the methacrylic resin and the solution phase of the block copolymer (B) Phase separates.

Along with the progress of the polymerization reaction, an action for stabilizing the whole phase works. By the shearing force by stirring, the solution phase of the methacrylic resin and the solution phase of the block copolymer (B) are phase-inverted, The solution phase of the system resin becomes a continuous phase, and the solution phase of the block copolymer (B) becomes a dispersed phase. When phase inversion occurs, the viscosity decreases. The polymerization conversion rate of the monomer mixture (A _m ) when this phase inversion occurs is the volume ratio of the solution phase of the methacrylic resin to the solution phase of the block copolymer (B), the block copolymer (B) The molecular weight, the graft ratio to the block copolymer (B) before phase inversion, and when a solvent is used, it varies depending on the amount of solvent and the type of solvent.

  Examples of the apparatus for performing polymerization while applying a shearing force to the raw material liquid include a tank reactor with a stirrer, a cylindrical reactor with a stirrer, a cylindrical reactor having a static stirring ability, and the like. One or more of these apparatuses may be used, or a combination of two or more different reactors may be used. The polymerization reactor may be either a batch type or a continuous type. The polymerization of the raw material liquid is preferably performed by a bulk polymerization method or a solution polymerization method from the initial stage of polymerization until phase inversion occurs.

  The diameter of the dispersed phase depends on factors such as the number of stirring revolutions in the case of a reactor equipped with a stirrer; the linear velocity of the reaction liquid, the viscosity of the polymerization system, and the phase inversion in the case of a static stirring reactor represented by a tower reactor It can be controlled by various factors such as the graft ratio to the previous block copolymer (B).

  A bulk polymerization method or a solution polymerization method can be applied to the polymerization after the phase inversion occurs, but a suspension polymerization method and a cast polymerization method can also be applied in addition to these.

In the present invention, the polymerization conversion rate of the monomer mixture (A _m ) is preferably 70% by mass or more, and more preferably 80% by mass or more. If the polymerization conversion rate is lower than this, the crosslinking reaction and graft reaction in the dispersed phase containing the block copolymer (B) formed by phase inversion hardly proceed sufficiently. When the crosslinking reaction and graft reaction are not sufficiently advanced, the dispersed phase in the methacrylic resin composition is easily broken by mechanical shearing such as an extruder or a kneader, and the impact strength is sufficient. At the same time, the mechanical strength may change depending on the molding method. In order to further advance the crosslinking reaction and graft reaction and increase the impact strength, it is preferable to add a polymerization initiator during the reaction. On the other hand, the polymerization conversion rate is preferably 95% by mass or less. If it exceeds 95% by mass, the molecular weight distribution of the continuous phase composed of the methacrylic resin (A) becomes wide, and the toughness tends to decrease.

  The presence or absence of a dispersed phase comprising the block copolymer (B) in the middle of polymerization and the diameter of the dispersed phase were determined by extracting a part of the raw material liquid during polymerization and subjecting it to suspension polymerization. A method of observing the morphology of a resin-based resin composition with a scanning electron microscope, or removing a part of a raw material liquid in the middle of polymerization and drying and devolatilizing it to remove unreacted monomers and solvents, and its composition The morphology of the product can be confirmed by a method of observing with a scanning electron microscope.

After the polymerization conversion rate of the monomer mixture (A _m ) reaches 70% by mass to 95% by mass, devolatilization is performed to remove the unreacted monomer and the solvent. Examples of the devolatilization method include an equilibrium flash method and an adiabatic flash method. In particular, in the adiabatic flash method, devolatilization is preferably performed at a temperature of 200 to 300 ° C, more preferably 220 to 270 ° C. Below 200 ° C., it takes time for devolatilization, and when devolatilization is insufficient, the methacrylic resin film may have a poor appearance such as silver. On the other hand, when the temperature exceeds 300 ° C., the methacrylic resin film may be colored due to oxidation or burn. Examples of the apparatus used for devolatilization include a flash drum, a biaxial devolatilizer, a thin film evaporator, and an extruder. The residual volatile content is preferably 0.5% by mass or less, more preferably 0.4% by mass or less, and still more preferably 0.3% by mass or less. When the residual volatile content exceeds 0.5% by mass, appearance defects such as silver are likely to occur in the methacrylic resin film.

  For methacrylic resin compositions, known antioxidants, UV absorbers, light stabilizers, lubricants, mold release agents, antistatic agents, flame retardants, dyes / pigments, light diffusing agents, flexibility modifiers are used as necessary. A quality agent, a fluorescent substance, etc. can be added. Moreover, a methacrylic resin composition can also be diluted with a normal methacrylic resin (D) and used. In addition, other resins such as AS resin, ABS resin, AES resin, AAS resin, MS resin, MBS resin, styrene resin, high-impact polystyrene resin, and vinyl chloride resin can be used.

Examples of the ultraviolet absorber include benzophenones, benzotriazoles, triazines, benzoates, salicylates, cyanoacrylates, oxalic anilides, malonic esters, formamidines, and the like. These can be used alone or in combination of two or more. Among these, from the viewpoint of suppressing the yellowness of the methacrylic resin film, an ultraviolet absorber having a maximum value ε _max of a molar extinction coefficient at a wavelength of 380 to 450 nm of 1200 dm ³ · mol ⁻¹ cm ⁻¹ or less is preferable, Ultraviolet absorbers having 600 dm ³ · mol ⁻¹ cm ⁻¹ or less are more preferable, and ultraviolet absorbers having 300 dm ³ · mol ⁻¹ cm ⁻¹ or less are particularly preferable.

In addition, the measurement of the maximum value ε _max of the molar extinction coefficient of the ultraviolet absorber is performed by sufficiently dissolving 10.00 mg of the ultraviolet absorber (molecular weight (Mw)) in 1 L of cyclohexane so that there is no undissolved substance by visual observation. This solution was poured into a 1 cm × 1 cm × 3 cm quartz glass cell, and the absorbance at a wavelength of 380 to 450 nm was measured using a U-3410 type spectrophotometer manufactured by Hitachi, Ltd. From the maximum value (A _max ), molar absorption was measured. The maximum coefficient ε _max was calculated by the following equation.
ε _max = [A _max / (10 × 10 ⁻³ )] × Mw
As an ultraviolet absorber having a maximum molar extinction coefficient ε _{max at a} wavelength of 380 to 450 nm of 1200 dm ³ · mol ⁻¹ cm ⁻¹ or less, 2-ethyl-2′-ethoxy-oxalanilide (Clariant Japan, Inc .; product) Name Sundeyuboa VSU).

  The amount of the ultraviolet absorber is preferably 0.001 to 5 parts by mass, more preferably 0.1 to 3 parts by mass, and further preferably 0.5 to 2 parts by mass with respect to 100 parts by mass of the methacrylic resin composition. It is. When the amount of the ultraviolet absorber is less than 0.001 part by mass, the effect of suppressing the resin deterioration due to ultraviolet rays tends not to be exhibited sufficiently. If the amount exceeds 5 parts by mass, the mold is likely to become dirty during molding, so that it is easy to cause a decrease in yield and productivity due to mold cleaning, etc., and to cause the occurrence of silver and to the eyes.

In the present invention, a light stabilizer such as a hindered amine such as a compound having a 2,2,6,6-tetraalkylpiperidine skeleton may be further contained.
Examples of hindered amines include dimethyl succinate / 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, poly ((6- (1,1,3 , 3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl) ((2,2,6,6-tetramethyl-4-pipedyl) imino) hexamethylene ((2,2, 6,6-tetramethyl-4-pipedyl) imino)), 2- (2,3-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate bis (1,2,2, 6,6-pentamethyl-4-piperidyl), 2- (3,5-di-tert-butyl-4-hydroxybenzyl) -2-n-butylmalonate bis (1,2,2,6,6-pentamethyl) -4-piperidyl), N, N′-bis (3-a Nopropyl) ethylenediamine / 2,4-bis (N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino) -6-chloro-1,3,5-triazine condensate, Examples thereof include bis (2,2,6,6-tetra-methyl-4-pipedyl) sebacate and bis (2,2,6,6-tetramethyl-4-piperidyl) succinate.
The amount of the light stabilizer is preferably 0.001 to 0.5 parts by mass with respect to 100 parts by mass of the methacrylic resin composition with respect to 100 parts by mass of the methacrylic resin composition.

  Examples of the antioxidant include phosphorus-based antioxidants, hindered phenol-based antioxidants, thioether-based antioxidants, and the like. These can be used alone or in combination of two or more. Among these, phosphorus antioxidants and hindered phenol antioxidants are preferably used from the viewpoint of preventing the deterioration of optical properties due to coloring.

  Examples of phosphorus antioxidants include 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite and bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphos. Phyto, tris (2,4-di-t-butylphenyl) phosphite, tetrakis (2,4-di-t-butylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite, bis [ 2,4-bis (1,1-dimethylethyl) -6-methylphenyl] ethyl ester phosphorous acid and the like. Among these, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite and tris (2,4-di-t-butylphenyl) phosphite are preferable.

  Examples of the hindered phenol antioxidant include triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3 , 5-di-t-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octyl) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3 , 5-triazine, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylenebis [3- (3,5-di- t-butyl-4-hydroxyphenylpropionate), octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, N, N′-hex Methylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide), 3,5-di-tert-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl -2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate, octyl Diphenylamine, 2,4-bis [(octylthio) methyl] -o-cresol, isooctyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, and the like. Among these, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (trade name “IRGANOX1010”, manufactured by Ciba Special Chemicals), octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate (trade name “IRGANOX1076”, manufactured by Ciba Special Chemicals) is preferable.

  The amount of the antioxidant is preferably 0.001 to 1 part by mass, more preferably 0.005 to 0.5 part by mass, and still more preferably 0.01 to 0 part per 100 parts by mass of the methacrylic resin composition. 3 parts by mass. If the amount of the antioxidant is less than 0.001 part by mass, the effect of preventing the heat coloring of the molded product at a high temperature tends not to be sufficiently exhibited. On the other hand, when the amount of the antioxidant exceeds 1 part by mass, it causes a decrease in yield due to mold contamination and a decrease in productivity due to mold cleaning, etc., and also causes a defect in the methacrylic resin film due to the occurrence of silver. Or the methacrylic resin film is burned and the hue is lowered, or foreign matter is generated on the methacrylic resin film.

  In order to improve roll releasability during film formation, a release agent may be contained in the resin composition. Examples of the mold release agent include higher alcohol and / or glycerin monoester. Examples of higher alcohols include cetyl alcohol and stearyl alcohol. Examples of the glycerin monoester used in the present invention include glycerides of higher fatty acids such as stearic acid monoglyceride and stearic acid diglyceride. When the higher alcohol and glycerol monoester are used in combination, the ratio is not particularly limited, but the mass ratio of higher alcohol / glycerol monoester is preferably 2.5 / 1 to 3.5 / 1, more preferably 2.8. / 1 to 3.2 / 1.

  The amount of the release agent is preferably 0.5 parts by mass or less, more preferably 0.3 parts by mass or less, and more preferably 0.1 parts by mass with respect to 100 parts by mass of the methacrylic resin composition. More preferably, it is as follows. If the amount of the release agent exceeds 0.5 parts by mass, there is a tendency to reduce the yield due to mold contamination and the productivity due to mold cleaning, and the occurrence of defects in the methacrylic resin film due to the occurrence of silver. It becomes easy to cause the eyes and the eyes at the time of extrusion molding.

  The polymer processing aid has an effect on thickness accuracy and thin film properties when molding a methacrylic resin composition. The polymer processing aid can be usually produced as polymer particles having a particle size of 0.05 to 0.5 μm by an emulsion polymerization method. The polymer particles may be so-called single layer particles having a single composition and a single intrinsic viscosity, or may be multi-layer particles having two or more layers having different compositions or intrinsic viscosities. Among these, particles having a two-layer structure having a low intrinsic viscosity layer in the inner layer and a high intrinsic viscosity layer having an intrinsic viscosity of 5 dl / g or more in the outer layer are preferable. The intrinsic viscosity of the polymer processing aid is 3 to 6 dl / g, and if it is less than 3 dl / g, a sufficient improvement effect on moldability is not recognized. If it exceeds 6 dl / g, the melt fluidity tends to be lowered.

  The compounding amount in the case of using the polymer processing aid is 0.05 to 10 parts by mass, preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the methacrylic resin composition. If the polymer processing aid is less than 0.05 parts by mass, a sufficient improvement effect on the thickness accuracy at the time of molding cannot be recognized. On the other hand, if it exceeds 10 parts by mass, the melt fluidity tends to be lowered.

Examples of the organic dye include terphenyl having a function of converting ultraviolet rays that are considered harmful to the resin into visible light.
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 fluorescent pigments, fluorescent dyes, fluorescent white dyes, fluorescent brighteners, and fluorescent bleaching agents.

  Moreover, you may use flexibility modifiers other than a block copolymer (B) for a methacrylic resin composition. Examples of other flexibility modifiers include a core-shell type modifier containing acrylic rubber or diene rubber as a core layer component, and a modifier containing a plurality of rubber particles. Other flexibility modifiers are preferably added in less than normal amounts to improve some of the properties.

  The methacrylic resin (D) used for dilution of the methacrylic resin composition is 80% by mass or more of repeating units derived from methyl methacrylate and 20% by mass or less of repeating units derived from a vinyl monomer copolymerizable therewith. Consists of Examples of copolymerizable vinyl monomers include methyl acrylate, ethyl acrylate, butyl acrylate, propyl acrylate, hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, Acrylic acid ester monomers such as benzyl acrylate; ethyl methacrylate, butyl methacrylate, propyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, and other methacrylic acid esters; vinyl acetate, styrene, Aromatic vinyl compounds such as p-methylstyrene, o-methylstyrene, m-methylstyrene, α-methylstyrene and vinylnaphthalene; nitriles such as acrylonitrile and methacrylonitrile; acrylic acid, methacrylic acid, α such as tons acid, beta-unsaturated carboxylic acid; N- ethylmaleimide, and the like maleimide compounds such N- cyclohexyl maleimide. Two or more of these vinyl monomers can be used in combination.

  The intrinsic viscosity of the methacrylic resin (D) used for dilution is 0.3 to 1.0 dl / g. When the intrinsic viscosity of the methacrylic resin (D) is less than 0.3, the tenacity when melt-molding the resulting methacrylic resin composition tends to decrease. On the other hand, when the intrinsic viscosity is 1.0 dl / g or more, the fluidity during melt molding tends to decrease. The compounding amount of the methacrylic resin (D) is preferably 1 to 100 parts by mass, more preferably 5 to 70 parts by mass with respect to 100 parts by mass of the methacrylic resin composition. When the compounding amount of the methacrylic resin (D) exceeds 100 parts by mass, the handleability of the resulting methacrylic resin film tends to decrease.

  The methacrylic resin (D) used for dilution is generally commercially available as a methacrylic resin as long as the above conditions are satisfied, and ISO 8257-1: 1997 (E) “Plastic—poly (methyl methacrylate) (PMMA) Includes materials specified in "Plastics-Poly (Methyl Methacrylate) (PMMA) molding and extrusion material-").

  There is no restriction | limiting in particular about the polymerization method for manufacturing the methacryl resin (D) used for dilution, Well-known polymerization methods, such as emulsion polymerization, suspension polymerization, block polymerization, and solution polymerization, are employable.

The methacrylic resin film of the present invention can be obtained by film-forming the methacrylic resin composition. As a film forming method, a known forming method such as a melt casting method, an extrusion forming method using a T die, an inflation forming method, or a blow forming method can be adopted. From the economical point of view, an extrusion forming method using a T die. Is preferred.
According to the extrusion method, it has excellent transparency, improved toughness, excellent handleability, excellent balance between toughness and surface hardness and rigidity, and when stretched, folded, subjected to impact and A methacrylic resin film that is difficult to whiten when placed under wet heat conditions for a long time can be obtained.

  Among the methods for obtaining the methacrylic resin film of the present invention, from the viewpoint that a methacrylic resin film having good surface smoothness, good specular gloss, and low haze can be obtained, the molten methacrylic resin composition is T. A method including a step of extruding in a molten state from a die and forming the extruded product by bringing both surfaces of the extruded product into contact with the mirror surface or the surface of the mirror belt is preferable. The roll or belt used at this time is preferably made of metal. Thus, when shape | molding by making both surfaces of an extrusion molding contact a mirror surface, it is preferable to press and pinch with a mirror roll or a mirror belt from both surfaces of an extrusion molding. The pinching pressure by the mirror roll or mirror belt is preferably higher, and the linear pressure is preferably 10 N / mm or more, and more preferably 30 N / mm or more.

  Further, from the viewpoint of obtaining a methacrylic resin film having good surface smoothness, good specular gloss, and low haze, the surface temperature of at least one of the specular roll or the specular belt is 60 ° C. or more and the specular roll or specular belt Both surface temperatures are preferably 130 ° C. or lower. When the surface temperature of both the mirror surface roll and the mirror surface belt is less than 60 ° C., the surface smoothness of the resulting methacrylic resin film tends to be insufficient and haze tends to increase. When at least one surface temperature exceeds 130 ° C., the methacrylic resin film and the mirror surface roll or mirror belt are in close contact with each other, so that the surface is easily roughened when the methacrylic resin film is peeled off from the mirror surface roll or mirror surface belt. The resulting methacrylic resin film tends to have a low surface smoothness or a high haze.

  The resin temperature in the extrusion molding method is preferably 160 to 260 ° C, more preferably 220 to 250 ° C. After melt molding, the methacrylic resin film is preferably cooled more rapidly than natural cooling. For example, it is preferable that the methacrylic resin film immediately after being formed is brought into contact with a cooling roll for rapid cooling. By performing such rapid cooling, a methacrylic resin film in which the block copolymer (B) is contained as a dispersed phase in the continuous phase composed of the methacrylic resin (A) can be obtained.

  The haze of the methacrylic resin film of the present invention is preferably 0.5% or less, more preferably 0.3% or less at a thickness of 100 μm. Thereby, it is excellent in the handleability at the time of a cutting | disconnection, the time of punching, etc., and is excellent in surface glossiness and transparency. Further, in optical applications such as a liquid crystal protective film and a light guide film, the use efficiency of the light source is preferably increased. Furthermore, it is preferable because it is excellent in shaping accuracy when performing surface shaping.

  The thickness of the methacrylic resin film of the present invention is usually 300 μm or less, preferably 30 to 300 μm. When it is thicker than 30 μm, good secondary workability is obtained. On the other hand, when the thickness is less than 300 μm, the rigidity and the secondary workability are improved because the rigidity is reduced.

  The methacrylic resin film of the present invention may be printed on at least one surface. Patterns such as pictures, characters, and figures, colors, and the like are given by printing. The pattern may be chromatic or achromatic. In order to prevent color fading of the printing layer, printing is preferably performed on the side in contact with the substrate described later.

  The methacrylic resin film of the present invention has a JIS pencil hardness (thickness of 100 μm), preferably HB or harder, more preferably F or harder, more preferably H or harder. It is preferable to use a methacrylic resin film having a hard surface because the surface hardness of the laminate of the present invention is also increased.

  The methacrylic resin film may be colored. As a coloring method, a method in which a pigment or dye is contained in a methacrylic resin composition to color the resin composition itself before molding; a dyeing method in which a methacrylic resin film is immersed and colored in a liquid in which the dye is dispersed. Although there is a law, it is not particularly limited.

The methacrylic resin film of the present invention may be a single layer film made of the methacrylic resin composition, or a multilayer film having a methacrylic resin composition layer and another methacrylic resin layer. Also good.
For example, the film which laminated | stacked the layer of the methacrylic-type resin composition and the layer of the methacrylic-type resin which does not contain a rubber particle is mentioned. In this case, the thickness of the layer of the methacrylic resin composition is preferably 50% or more, more preferably 60% or more with respect to the thickness of the entire multilayer film. In order to manufacture such a methacrylic resin film having a multilayer structure, for example, a known multilayer extrusion having a plurality of extruders and a mechanism such as a multi-manifold system or a feed block system for laminating resins extruded from them. A machine can be used.

The laminate of the present invention is obtained by laminating the methacrylic resin film of the present invention on a base material.
Examples of the base material include various resin molded articles; metal molded articles; wooden molded articles; and fiber products such as paper and cloth. In particular, a metal molded body such as a steel plate or a wooden molded body is preferably used for building materials or vehicle materials.

  A well-known resin is used for the resin-made molded object as a base material. Polycarbonate polymers, vinyl chloride polymers, vinylidene fluoride polymers, methacrylic resins, MS resins, ABS resins and AS resins are particularly preferred. The shape of the resin molded body is not particularly limited, but a sheet, a film or a plate is preferable. Printing may be performed on the surface of the resin molded body. Patterns such as pictures, characters, and figures, colors, and the like are given by printing. The pattern may be chromatic or achromatic. The resin molded body as the substrate can be obtained by a known molding method such as an extrusion molding method or an injection molding method.

  The laminate is prepared by separately preparing the methacrylic resin film and the base material, a method of laminating continuously between heating rolls, a method of thermocompression bonding with a press, a method of laminating simultaneously with pressure air or vacuum forming, adhesion Method of laminating layers (wet lamination); Method of casting molten base resin on methacrylic resin film; Method of coextrusion molding of base resin and methacrylic resin composition And so on.

The thermocompression bonding between the methacrylic resin film and the substrate can be performed using a known means such as a hot press machine or a hot roll machine. The temperature at the time of thermocompression bonding is usually 100 to 200 ° C.
It is also possible to place a methacrylic resin film in a mold, etc., pour the molten base resin onto the methacrylic resin film, and laminate the methacrylic resin film simultaneously with the molding of the resin base material. it can.

  In the production by the co-extrusion method, the melted base resin and the melted methacrylic resin composition are poured into a die for co-extrusion such as a feed block method or a multi-manifold method, and each is extruded simultaneously. The temperatures of the melted base resin and the melted methacrylic resin composition are adjusted as appropriate so that the disturbance of the interface between the base resin and the methacrylic resin composition is reduced. The coextruded molten resin is preferably a method comprising a step of forming both surfaces of the coextruded molten resin in contact with the mirror roll surface or the mirror belt surface in the same manner as described in the description of the production of the methacrylic resin film. The temperature and linear pressure of the mirror roll surface or the mirror belt surface can be selected as appropriate, but it should be in the condition range described in the description of the production of the methacrylic resin film for good surface smoothness, good specular gloss, low This is preferable in that a haze laminate can be obtained.

The laminate of the present invention is less likely to be whitened due to surface hardness, weather resistance, adhesion when subjected to hard coat treatment, toughness, surface smoothness, transparency (haze), warm water of a methacrylic resin film, and the like. From the standpoint of maintaining the feature, it is preferable that the methacrylic resin film is the outermost layer.
In the laminate of the present invention, another layer may be interposed between the substrate and the methacrylic resin film. Examples of the other layer include a layer made of a thermoplastic resin that may be colored and excellent in transparency, and an adhesive layer. Although the adhesive agent used for an adhesive bond layer is not restrict | limited in particular, In order to maintain transparency, it is preferable to use a transparent adhesive agent.
In addition, in order to improve adhesiveness etc. with another layer, you may perform surface treatments, such as a plasma process, an electron beam process, a corona treatment, on the surface of a methacrylic resin film and / or a base material.

The thickness of the methacrylic resin film in the laminate of the present invention is preferably 5 to 200 μm, more preferably 50 to 200 μm, and particularly preferably 50 to 125 μm.
When the thickness of the methacrylic resin film in the laminate of the present invention is less than 5 μm, the surface hardness of the laminate is insufficient. In applications that require weather resistance, a sufficient amount of UV absorber cannot be retained in the methacrylic resin film, and the mechanical properties of the laminate deteriorate over time. Moreover, when the thickness of the methacrylic resin film in the laminate of the present invention exceeds 200 μm, the methacrylic resin film tends to break when stretched, bent and / or subjected to an impact. Moreover, it tends to be disadvantageous in terms of economy.

  The laminate of the present invention takes advantage of the excellent transparency and surface smoothness of methacrylic resin films, high surface hardness, hot water whitening resistance, and good appearance (low roughness), and corrugated sheets, carports. , Roofing materials such as arcades and balconies, wall materials, construction materials and housing equipment such as highway fences, sound insulation walls, nameplates, liquid crystal display covers, touch panels, display dummy cans, vehicle windows, pachinko machines, mobile phone front plates, Can be used in a wide range of industrial and industrial applications such as insulators, LCD TV diffusers, Fresnel lenses such as projection TVs, lenticular lenses, LCDs, PTVs, projection TV front plates, lens sheets, and other optical applications; .

  In particular, the methacrylic resin film and laminate of the present invention are excellent in hot water whitening resistance, surface hardness, and weather resistance, and are therefore suitable for building materials such as vehicle interiors, furniture, door materials, and baseboards. Particularly suitable for exterior and semi-exterior applications where water resistance is required. Specifically, it can be suitably used for window frames, entrance doors, shutters, and outer walls.

  The methacrylic resin film of the present invention is more suitable for the production of optical members than conventional acrylic resin films, and the resulting film has few fish eyes and excellent surface properties and surface hardness. Specific examples of use are suitable for liquid crystal protective plates, surface materials for portable information terminals, display window protective films for portable information terminals, light guide films, and front plates for various displays.

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to the following examples. In the synthesis of the block copolymer, chemicals dried and purified by a conventional method were used. At that time, measurement of the polymerization conversion rate and analysis of the synthesized block copolymer were carried out by the following methods. Moreover, the analysis, dynamics, and optical measurement of the methacrylic resin composition were performed by the following methods.

(1) Measurement of number average molecular weight (Mn), weight average molecular weight (Mw), molecular weight distribution (Mw / Mn) and block copolymer production rate by gel permeation chromatography (GPC) Apparatus: Gel Perm manufactured by Tosoh Corporation Eation chromatograph (HLC-8020)
Column: Tosoh TSKgel G2000H _HR (1) and GMH _HR- M (2) connected in series Eluent: Tetrahydrofuran Eluent flow rate: 1.0 ml / min Column temperature: 40 ° C
Detection method: differential refractive index (RI) meter Calibration curve: created using standard polystyrene

(2) Measurement of polymerization conversion rate of charged monomer by gas chromatography (GC) Apparatus: Gas chromatograph GC-14A manufactured by Shimadzu Corporation
Column: GL Sciences Inc. INERT CAP 1 (df = 0.4 μm, 0.25 mm ID × 60 m)
Analysis conditions: injection temperature 180 ° C., detector temperature 180 ° C., 60 ° C. (hold for 5 minutes) → temperature increase rate 10 ° C./min→200° C. (hold for 10 minutes)

(3) Amount of side chain vinyl bonds The block copolymer was dissolved in deuterated chloroform to obtain a test solution, and the test solution was analyzed using ¹ H-NMR (JEOL nuclear magnetic resonance apparatus (JNM-LA400)). , A chemical shift of 4.7 to 5.2 ppm (hereinafter referred to as signal C ₀ ), 1,2-vinyl proton (= CH ₂ ), and a chemical shift of 5.2 to 5.8 ppm (hereinafter referred to as signal D ₀ ). )) Was determined by calculating the integral intensity of vinyl protons (= CH-) and calculating the side chain vinyl bond amount V ₀ [mol%] by the following equation.
V ₀ = _{[(C 0/2) / {} C 0/2 + (D 0 -C 0/2) / 2} ] × 100

(4) Analysis of molecular structure of block copolymer by nuclear magnetic resonance spectrum ( ¹ H-NMR spectrum) Instrument: JEOL nuclear magnetic resonance apparatus (JNM-LA400)
Solvent: deuterated chloroform

(5) Glass transition temperature (Tg)
The glass transition temperature (Tg) of poly (n-butyl acrylate) used as the polymer block (a) is the value described in “POLYMER HANDBOOK FOURTH Edition, page VI / 199, Wiley Interscience, New York, 1998” (−49 ° C) was used.
The glass transition temperature (Tg) of poly1,3-butadiene used as the polymer block (b) is 1,2-vinyl bond amount described in “ANIONIC POLYMERIZATION, page 434, MARCEL DEKKER, Inc. 1996”. A value derived from the relationship between Tg and Tg was used.

(6) Refractive index (nd)
The block copolymer (B) was uniformly dissolved in toluene so as to be 30% by mass. The density and refractive index of the solution and toluene were measured at room temperature, and the refractive index of the block copolymer (B) was determined using the following formulas (Formula 1) to (Formula 3). Furthermore, polymethyl methacrylate having a known refractive index (nd = 1.492) was measured by the same method, and a refractive index measurement calibration coefficient was obtained by this method to calibrate the refractive index of the block copolymer (B). .
(Nd ² −1) / (nd ² +2) × V = r = constant (Expression 1)
r ₃ = w ₁ r ₁ + w ₂ r ₂ (Formula 2)
V ₂ = 1 / ρ ₁ −1 / w ₂ (1 / ρ ₁ −1 / ρ ₃ ) (Equation 3)
nd: refractive index, V: specific volume, r: molecular refraction, w: mass fraction ρ: density subscript 1: toluene subscript 2: block copolymer (B) subscript 3: solution Actual measurement: V ₃ , nd ₃ , V ₁ , nd ₁
Formula (1) and Formula (2) Source: Polymer Experimental Studies Vol. 12 Thermodynamic, Electrical and Optical Properties 1984 Kyoritsu Publishing Formula (3) Source: Polymer Experimental Studies Vol. 11 Polymer Solution Showa 57 years Kyoritsu Publishing

(7) Morphology The molded product was cut out using a diamond knife to obtain an ultrathin section, this section was stained with osmium tetroxide, and an observation image was photographed using a transmission electron microscope. A dispersed phase comprising 30 block copolymers (B) was selected at random, the diameters of the dispersed phases were measured, and the average value thereof was expressed.
In addition, the polymer block (b) in the block copolymer (B) is dyed by the above dyeing, and the morphology of the methacrylic resin composition can be observed. The methacrylic resin composition of the present invention contains a continuous phase composed of an undyed methacrylic resin (A) and a dispersed phase comprising a dyed block copolymer (B). The thing of the sea island structure of the dye | stained part (the sea phase which consists of block copolymers (B)) and the part which is not dyed (the island phase which consists of methacrylic resin (A)) is contained.

(8) Evaluation of transparency Haze of a molded product having a thickness of 1 mm was measured in accordance with ISO14782.

(9) Evaluation of surface hardness Based on JIS K5600-5-4, pencil hardness was measured with an injection molded product having a thickness of 3 mm under a load of 0.75 kg.

(10) Warm water whitening resistance The light transmittance (visible light: 600 nm) of a 3 mm thick flat plate prepared by injection molding was measured. The flat plate was immersed in warm water at 80 ° C. for 12 hours. Then, it was immersed in distilled water at room temperature, and the flat plate was cooled to room temperature. It was taken out from water and the surface moisture was wiped off with gauze, and the light transmittance (visible light: 600 nm) was measured. The difference in light transmittance before and after immersion was determined.

<< Synthesis Example 1 >> Production of Block Copolymer (B-1) (1) 801 ml of toluene and 0.007 ml of 1,2-dimethoxyethane were put into a 1.5 liter autoclave vessel equipped with a stirrer and purged with nitrogen for 20 minutes. Went. Thereto was added 1.9 ml of a cyclohexane solution of sec-butyllithium having a concentration of 1.3 mol / l, then 97 ml of 1,3-butadiene was added and reacted at 30 ° C. for 3 hours to obtain a 1,3-butadiene polymer. A reaction mixture containing was obtained.
As a result of sampling analysis of a part of the obtained reaction mixture, the 1,3-butadiene polymer in the reaction mixture has a number average molecular weight (Mn) of 48,700 and a molecular weight distribution (Mw / Mn) of 1.06. The side chain vinyl bond content was 30 mol%, and the glass transition temperature of the 1,3-butadiene polymer (polymer block (b)) was -77 ° C.

(2) The reaction mixture obtained in (1) above is cooled to −30 ° C., and toluene containing 0.45 mol / l isobutylbis (2,6-di-t-butyl-4-methylphenoxy) aluminum 18.1 ml of the solution and 8.1 ml of 1,2-dimethoxyethane were added and stirred for 10 minutes to obtain a homogeneous solution.

(3) Next, 71 ml of n-butyl acrylate was added while vigorously stirring the solution obtained in the above (2), and polymerized at −15 ° C. for 3 hours. A part of the obtained reaction mixture was sampled, and the molecular weight was analyzed by GPC (polystyrene conversion). As a result, the butadiene-n-butyl acrylate diblock copolymer (arm polymer block) in the reaction mixture was a number average molecular weight. The weight average molecular weight / number average molecular weight ratio (Mw / Mn) was 1.02. The glass transition temperature of the polymer block (a) obtained by polymerization of n-butyl acrylate was −49 ° C.

(4) The reaction mixture obtained in the above (3) was kept at −15 ° C., and with vigorous stirring, 2.1 ml of 1,6-hexanediol diacrylate was added and polymerized for 30 minutes. Then about 1 ml of methanol was added to stop the polymerization.

(5) The block copolymer (B-1) was obtained by putting the reaction mixture obtained by said (4) in 8000 ml of methanol, and making it precipitate. The yield of the obtained block copolymer (B-1) was almost 100%.

The obtained block copolymer (B-1) was a mixture of a star block copolymer and an arm polymer block. In the block copolymer (B-1), the ratio of the star block copolymer calculated from the area ratio of GPC was 92% by mass.
The star block copolymer had a number average molecular weight (Mn) of 310,000 (number of arms = 3.88) and an Mw / Mn of 1.16. The block copolymer (B-1) is a polymer block (b) consisting of 49% by mass of a repeating unit derived from 1,3-butadiene and a polymer block consisting of a repeating unit derived from n-butyl acrylate ( a) A diblock copolymer comprising 51% by mass was contained as an arm polymer block.
The refractive index of the block copolymer (B-1) was 1.492. Table 1 shows the characteristics of the block copolymer (B-1). In the table, BA means n-butyl acrylate, and Bd means 1,3-butadiene.

<< Synthesis Example 2 >> Production of Block Copolymer (B-2) (1) 801 ml of toluene was put into a 1.5 liter autoclave vessel equipped with a stirrer and purged with nitrogen for 20 minutes. Then, 1.9 ml of a cyclohexane solution of sec-butyllithium having a concentration of 1.3 mol / l was added, and then 105 ml of 1,3-butadiene was added and reacted at 30 ° C. for 3 hours to obtain a 1,3-butadiene polymer. A reaction mixture containing was obtained.
As a result of sampling analysis of a part of the obtained reaction mixture, the 1,3-butadiene polymer in the reaction mixture has a number average molecular weight (Mn) of 46,700 and a molecular weight distribution (Mw / Mn) of 1.06. The side chain vinyl bond content was 10 mol%, and the glass transition temperature of the 1,3-butadiene polymer (polymer block (b)) was -95 ° C.

(2) The reaction mixture obtained in (1) above is cooled to −30 ° C., and toluene containing 0.45 mol / l isobutylbis (2,6-di-t-butyl-4-methylphenoxy) aluminum 18.1 ml of the solution and 8.1 ml of 1,2-dimethoxyethane were added and stirred for 10 minutes to obtain a homogeneous solution.

(3) Next, while vigorously stirring the solution obtained in the above (2), 65 ml of n-butyl acrylate was added and polymerized at −15 ° C. for 3 hours. A part of the obtained reaction mixture was sampled, and the molecular weight was analyzed by GPC (polystyrene conversion). The weight average molecular weight / number average molecular weight ratio (Mw / Mn) was found to be 1.02. The glass transition temperature of the polymer block (a) obtained by polymerization of n-butyl acrylate was −49 ° C.

(4) The reaction mixture obtained in the above (3) was kept at −15 ° C., and with vigorous stirring, 2.1 ml of 1,6-hexanediol diacrylate was added and polymerized for 30 minutes. Then about 1 ml of methanol was added to stop the polymerization.

(5) A block copolymer (B-2) was obtained by putting the reaction mixture obtained in the above (4) into 8000 ml of methanol and precipitating it. The yield of the obtained block copolymer (B-2) was almost 100%.

The obtained block copolymer (B-2) was a mixture of a star block copolymer and an arm polymer block. In the block copolymer (B-2), the ratio of the star block copolymer calculated from the area ratio of GPC was 93% by mass.
The star block copolymer had a number average molecular weight (Mn) of 308,000 (number of arms = 3.88) and an Mw / Mn of 1.16. The block copolymer (B-2) is a polymer block (b) consisting of 53% by mass of a repeating unit derived from 1,3-butadiene and a polymer block consisting of a repeating unit derived from n-butyl acrylate ( a) It contained a diblock copolymer consisting of 47% by mass as an arm polymer block.
The refractive index of the block copolymer (B-2) was 1.492. Table 1 shows the characteristics of the block copolymer (B-2).

<< Synthesis Example 3 >> Production of Diblock Copolymer (B-3) (1) To a 1.5 liter autoclave vessel equipped with a stirrer, 801 ml of toluene and 0.007 ml of 1,2-dimethoxyethane were charged and nitrogen was added for 20 minutes. Purging was performed. Then, 1.9 ml of a cyclohexane solution of sec-butyllithium having a concentration of 1.3 mol / l was added, and then 95 ml of 1,3-butadiene was added and reacted at 30 ° C. for 3 hours to obtain a 1,3-butadiene polymer. A reaction mixture containing was obtained.
As a result of sampling analysis of a part of the obtained reaction mixture, the 1,3-butadiene polymer in the reaction mixture has a number average molecular weight (Mn) of 48,700 and a molecular weight distribution (Mw / Mn) of 1.06. The side chain vinyl bond content was 30 mol%, and the glass transition temperature of the 1,3-butadiene polymer (polymer block (b)) was -77 ° C.

(2) The reaction mixture obtained in (1) above is cooled to −30 ° C., and toluene containing 0.45 mol / l isobutylbis (2,6-di-t-butyl-4-methylphenoxy) aluminum 18.1 ml of the solution and 8.1 ml of 1,2-dimethoxyethane were added and stirred for 10 minutes to obtain a homogeneous solution.

(3) Next, while vigorously stirring the solution obtained in the above (2), 72 ml of n-butyl acrylate was added and polymerized at −15 ° C. for 3 hours. A part of the obtained reaction mixture was sampled, and the molecular weight was analyzed by GPC (polystyrene conversion). As a result, the butadiene-n-butyl acrylate diblock copolymer (arm polymer block) in the reaction mixture was a number average molecular weight. The weight average molecular weight / number average molecular weight ratio (Mw / Mn) was 1.02. The glass transition temperature of the polymer block (a) obtained by polymerization of n-butyl acrylate was −49 ° C.

(4) The block copolymer (B-3) was obtained by putting the reaction mixture obtained by said (3) in 8000 ml of methanol, and precipitating. The yield of the obtained block copolymer (B-3) was almost 100%.

<< Synthesis Example 4 >> Production of Block Copolymer (B-4) The amount of 1,2-dimethoxyethane was changed to 0.014 ml, the amount of 1,3-butadiene was changed to 87 ml, and the amount of n-butyl acrylate Was changed to 78 ml, and the block copolymer (B-4) was obtained by the same method as in Synthesis Example 1 except that the amount of 1,6-hexanediol diacrylate was changed to 2.6 ml. The block copolymer (B-4) is mainly composed of a star block copolymer composed of 44% by mass of repeating units derived from 1,3-butadiene and 56% by mass of repeating units derived from n-butyl acrylate. The polymer block (b) made of 1,3-butadiene has a vinyl bond content of 49 mol%, a glass transition temperature of −60 ° C., and a polymer block made of n-butyl acrylate (a ) Had a glass transition temperature of -49 ° C. The butadiene-n-butyl acrylate diblock copolymer (arm polymer block) had a number average molecular weight of 78,000 and a weight average molecular weight / number average molecular weight ratio (Mw / Mn) of 1.02. It was. The number average molecular weight (Mn) of the star block copolymer is 400,000 (number of arms = 5.13), and its Mw / Mn is 1.14. The star block copolymer calculated from the area ratio of GPC is used. The proportion of the polymer was 90% by mass. The refractive index of the block copolymer (B-4) is 1.492. Table 1 shows the characteristics of the block copolymer (B-4).

Synthesis Example 5 Production of Block Copolymer (B-5) The same method as Synthesis Example 1 except that the amount of 1,3-butadiene was changed to 158 ml and the amount of n-butyl acrylate was changed to 28 ml. As a result, a block copolymer (B-5) was obtained. The block copolymer (B-5) is mainly composed of a star block copolymer comprising 80% by mass of repeating units derived from 1,3-butadiene and 20% by mass of repeating units derived from n-butyl acrylate. The polymer block (b) made of 1,3-butadiene has a vinyl bond content of 30 mol%, a glass transition temperature of −46 ° C., and a polymer block made of n-butyl acrylate (a ) Had a glass transition temperature of -49 ° C. The butadiene-n-butyl acrylate diblock copolymer (arm polymer block) has a number average molecular weight of 69,000 and a weight average molecular weight / number average molecular weight ratio (Mw / Mn) of 1.02. It was. The number average molecular weight (Mn) of the star block copolymer is 270,000 (number of arms = 3.91), and its Mw / Mn is 1.16, and the star block copolymer calculated from the area ratio of GPC is used. The proportion of the polymer was 90% by mass. The refractive index of the block copolymer (B-5) is 1.507. Table 1 shows the properties of the block copolymer (B-5).

<< Synthesis Example 6 >> Production of Block Copolymer (B-6) The same method as Synthesis Example 1 except that the amount of 1,3-butadiene was changed to 40 ml and the amount of n-butyl acrylate was changed to 111 ml. As a result, a block copolymer (B-6) was obtained. The block copolymer (B-6) is mainly composed of a star block copolymer comprising 20% by mass of repeating units derived from 1,3-butadiene and 80% by mass of repeating units derived from n-butyl acrylate. The polymer block (b) made of 1,3-butadiene has a vinyl bond content of 30 mol%, a glass transition temperature of −77 ° C., and a polymer block made of n-butyl acrylate (a ) Had a glass transition temperature of -49 ° C. The butadiene-acrylic acid n-butyl diblock copolymer (arm polymer block) has a number average molecular weight of 69,000 and a weight average molecular weight / number average molecular weight ratio (Mw / Mn) of 1.02. It was. The number average molecular weight (Mn) of the star block copolymer is 272,000 (number of arms = 3.94), and its Mw / Mn is 1.15, and the star block copolymer calculated from the area ratio of GPC is used. The proportion of the polymer was 90% by mass. The refractive index of the block copolymer (B-6) is 1.473. Table 1 shows the characteristics of the block copolymer (B-6).

Example 1
An autoclave equipped with a stirrer and a sampling tube was charged with 57.8 parts by weight of purified methyl methacrylate, 3.0 parts by weight of methyl acrylate and 35 parts by weight of toluene, and 4.2 parts by weight of the block copolymer (B-1). Part was added and stirred at 30 ° C. for 8 hours to uniformly dissolve the block copolymer (B-1). Next, 0.0375 parts by mass of 1,1-di (t-butylperoxy) cyclohexane (“Perhexa C” manufactured by NOF Corporation, hydrogen abstraction capacity: 35%, 1 hour half-life temperature: 111.1 ° C.) and n -The raw material liquid was obtained by adding 0.1 mass part of octyl mercaptan and making it melt | dissolve uniformly. Oxygen in the reaction system was removed with nitrogen.
The raw material liquid was discharged from the autoclave in a constant amount, and supplied to the 3 L tank reactor A (theoretical complete mixing type reactor) controlled at a temperature of 125 ° C. in a constant amount. Polymerization was carried out in a tank reactor A with an average residence time of 45 minutes. The reaction solution was collected from the collection tube of the reactor A. The polymerization conversion measured by gas chromatography was 44% by mass.

  In a pipe part equipped with a static mixer manufactured by Noritake Engineering Co., Ltd., 1,1-di (t-butylperoxy) cyclohexane (“Perhexa C” manufactured by Nippon Oil & Fats Co., Ltd., hydrogen drawing capacity: 35%, 1 hour half-life temperature: 111 .1 ° C) is added to the liquid discharged at a constant flow rate from the reactor A so that the amount is 0.003 parts by mass with respect to the whole raw material liquid, and the liquid is a 5 L tank reactor controlled at 135 ° C. B (theoretical complete mixing reactor) was fed at a constant flow rate. Polymerization was carried out in reactor B with an average residence time of 90 minutes. The reaction solution was collected from the collection tube of the reactor B. The polymerization conversion measured by gas chromatography was 70% by mass.

  In the pipe part equipped with a static mixer manufactured by Noritake Engineering Co., Ltd., t-butyl peroxybenzoate ("Perbutyl Z" manufactured by Nippon Oil & Fats Co., Ltd., hydrogen abstraction capacity: 56%, 1 hour half-life temperature: 124.7 ° C) is a raw material solution. A pipe type equipped with a static mixer manufactured by Noritake Engineering Co., Ltd. whose inner wall temperature is controlled to 135 ° C. is added to the liquid discharged at a constant flow rate from the reactor B so that the total amount becomes 0.02 parts by mass. Reactor C (theoretical plug flow reactor) was fed at a constant flow rate. Polymerization was carried out in tube reactor C with an average residence time of 10 minutes. The internal pressure of the tubular reactor C was 0.7 MPa. The reaction solution was collected from the outlet of the tubular reactor C. The polymerization conversion measured by gas chromatography was 80% by mass.

  The liquid discharged from the tubular reactor C at a constant flow rate was supplied at a constant flow rate to a tubular reactor D equipped with a static mixer manufactured by Noritake Engineering, whose inner wall temperature was controlled to 140 ° C. Polymerization was carried out in a tubular reactor D (theoretical plug flow reactor) with an average residence time of 50 minutes. The internal pressure of the tubular reactor D was 0.7 MPa. The reaction solution was fractionated from the outlet of the tubular reactor D. The polymerization conversion measured by gas chromatography was 90% by mass.

  The liquid discharged from the tubular reactor D at a constant flow rate was heated to 230 ° C. and supplied to a twin screw extruder controlled at 260 ° C. at a constant flow rate. In the twin-screw extruder, volatile components mainly composed of unreacted monomers were separated and removed, and the reaction product was extruded in a strand shape. The strand was cut with a pelletizer to obtain a pellet-like methacrylic resin composition. The residual volatile content was 0.1% by mass.

The pellet-like methacrylic resin composition was produced by injection molding to produce a molded plate having a thickness of 3 mm and a molded plate having a thickness of 1 mm, and used as a test piece for evaluation.
The methacrylic resin composition contains 93 mass parts of a methacrylic resin composed of 95 mass% of repeating units derived from methyl methacrylate and 5 mass% of repeating units derived from methyl acrylate. 7 parts by mass of a block copolymer (B-1) having a polymer block (a) composed of repeating units derived from butyl and a polymer block (b) composed of repeating units derived from butadiene was dispersed as a dispersed phase. It was.
The dispersed phase observed with an electron microscope has a sea-island structure composed of a dyed sea phase (block copolymer (B)) and an undyed island phase (methacrylic resin (A)). Things were included. The disperse phase of the sea-island structure in which the area of the island portion occupies 20% or more of the area of the disperse phase was 20% by mass or more of the total disperse phase.

The pellet-like methacrylic resin composition was melt-extruded through a T-die extruder having a lip width of 300 mm and an upper and lower gap of 0.3 mm, and was drawn while being stretched in the vertical direction to continuously produce a film having a thickness of 0.2 mm. .
The film produced and the surface smoothness of the film produced between the lapse of 10 minutes and the lapse of 30 minutes from the start of extrusion were evaluated.

(Film forming property)
The minimum thickness D _min [mm] and the maximum thickness D _max [mm] of the film were determined, and the thickness variation rate defined by the following equation was determined.
Film thickness variation rate (%) = {(D _max −D _min ) / D _min } × 100
The film forming property was evaluated according to the following criteria.
A: The thickness variation rate is less than 5%, and the film formability is very good.
A: The thickness variation rate is 5 to 20%, and the film moldability is almost good.
X: The thickness variation rate exceeds 20%, and the film formability is extremely poor.

(Surface smoothness)
The film surface was visually observed and the surface smoothness was evaluated according to the following criteria.
○: The surface is smooth and good.
X: The surface is uneven and becomes frosted glass.

(Film appearance evaluation)
The pellet-like methacrylic resin composition was melt-extruded through a T-die extruder having a lip width of 300 mm and a vertical gap of 0.2 mm, and was drawn while being stretched in the vertical direction to produce a film having a thickness of 0.05 mm.
Using a gel counter (model FS-5 / manufactured by Optical Control Systems), the number per unit area of the film (fish eye) was measured. The appearance was evaluated according to the following criteria.
○: The number per square meter area is less than 10,000. △: The number per square meter area is 10,000 or more and less than 50,000. ×: The number per square meter area is 50,000 or more.

(Laminate formability)
The pellet-like methacrylic resin composition and methacrylic resin (Kuraray Co., Ltd., Parapet HR-L) were coextruded at a thickness of 50 μm / 2 mm to obtain a laminated film.
The laminated film is visually observed to determine whether there is whitening at the flow mark and the layer interface. When the flow mark and the layer interface are not whitened, the result is good (◯). The case where whitening had occurred was evaluated as defective (x).

(Bending characteristics)
A polyurethane primer was applied to both sides of a 100 μm polypropylene film, and silk screen printing was applied to one side thereof. On the printing surface side of this printing film, a methacrylic resin film having a thickness of 0.2 mm obtained by the extrusion molding was laminated with an embossing roll to obtain a laminated film.
A polyurethane adhesive was applied to the polypropylene film surface of the laminated film and bonded to a steel plate having a thickness of 0.5 mm to obtain a laminate having a methacrylic resin film layer on the surface layer.
The laminate was cut into a size of 10 cm × 10 cm, bent at 90 degrees and held for 4 seconds in a 20 ° C. atmosphere so that the radius of curvature was 3 mm (90 ° C. bending test). A similar bending test was performed in an atmosphere of −10 ° C.
The bending properties were evaluated according to the following criteria.
◯: Good without film breaks and cracks Δ: Film cracks occurred ×: Film breaks occurred Table 2 shows the evaluation results.

<< Examples 2-4, Comparative Examples 1-2 >>
Pellets were obtained in the same manner as in Example 1 except that the block copolymer (B-1) used in Example 1 was changed to the block copolymers (B-2) to (B-6) shown in Table 2. A methacrylic resin composition was obtained, and using the obtained pellet-shaped methacrylic resin composition, a molded plate having a thickness of 3 mm and a molded plate having a thickness of 1 mm were prepared and used as test pieces for evaluation. Any methacrylic resin composition has a residual volatile content of 0.1% by mass, and the sea-island structure of the dispersed phase is 20% by mass of the total dispersed phase. % Or more.
A film and a laminate were obtained in the same manner as in Example 1. Evaluation similar to Example 1 was performed. The results are shown in Table 2.

<< Comparative Example 3 >>
A pellet of a polymer composition obtained by kneading 50 parts by mass of core-shell polymer particles containing 40% by mass of styrene-n-butyl acrylate random copolymer rubber having a particle size of 0.25 μm with 50 parts by mass of a methacrylic resin. Using the same method as in Example 1, a 3 mm thick molded plate and a 1 mm thick molded plate were produced by injection molding to obtain a test piece for evaluation. Moreover, the film and the laminated body were obtained by the same method as Example 1. Evaluation similar to Example 1 was performed. The results are shown in Table 2.

  As shown in Table 2, a polymer block comprising a repeating unit derived from a (meth) acrylic acid alkyl ester in a continuous phase comprising a methacrylic resin (A) having 50% by mass or more of a repeating unit derived from methyl methacrylate. A film having a layer made of a methacrylic resin composition comprising a block copolymer (B) having (a) and a polymer block (b) comprising a repeating unit derived from a conjugated diene compound as a dispersed phase; It turns out that a laminated body (Examples 1-4) is excellent in surface hardness, an external appearance (low roughness), transparency, surface smoothness, hot water whitening resistance, and a low temperature characteristic compared with Comparative Examples 1-3.

  The methacrylic resin film and laminate of the present invention have features such as a beautiful appearance, high transparency and excellent weather resistance, and also have surface hardness, toughness, surface smoothness, appearance (low roughness), transparency, Excellent hot water whitening resistance and low temperature characteristics. Signboard parts, display parts, lighting parts, interior parts, building parts, transportation equipment parts, electronic equipment parts, medical equipment parts, equipment related parts, optical related parts, transportation related. It can be applied to parts, building material members, household appliance members, and the like.

Claims (11)

100 parts by mass of a continuous phase composed of a methacrylic resin (A) having a repeating unit derived from methyl methacrylate of 50% by mass or more has a glass transition temperature of 23 ° C. or less composed of a repeating unit derived from an alkyl (meth) acrylate. A block copolymer having a polymer block (a) of 30 to 65% by mass and a polymer block (b) of 35 to 70% by mass having a glass transition temperature of 0 ° C. or less composed of repeating units derived from a conjugated diene compound A film having a layer made of a methacrylic resin composition containing 1 to 80 parts by mass of the combined body (B) as a dispersed phase ,
The block copolymer (B) is a star block copolymer, the star block copolymer is composed of arm polymer blocks, and the number average in terms of polystyrene calculated by gel permeation chromatography (GPC) The molecular weight is the formula:
A methacrylic resin film satisfying [number average molecular weight of star block copolymer]> 2 × [number average molecular weight of arm polymer block] . Star block copolymer has the chemical structural formula:
(Polymer block (b) -polymer block (a)-) _n X
(Wherein, X is a coupling residue, n represents represents. A number greater than 2) methacrylic resin film according to claim 1 is represented by. The methacrylic resin film according to any one of claims 1 and 2 , wherein the block copolymer (B) has a refractive index of 1.48 to 1.50. The methacrylic resin film according to any one of claims 1 to 3 , wherein at least one surface is printed. The laminated body formed by laminating | stacking the methacrylic-type resin film of any one of Claims 1-4 on a base material. The laminate according to claim 5 , wherein the substrate has a layer made of a thermoplastic polymer. Thermoplastic polymers, polycarbonate based polymers, vinyl chloride polymers, vinylidene fluoride-based polymer, a methacrylic resin, MS resin, to claim 6 is at least one selected from the group consisting of ABS resin and AS resin The laminated body of description. The laminate according to claim 5 , wherein the substrate is a decorative sheet formed by printing on a thermoplastic resin sheet. The laminate according to claim 5 , wherein the substrate is a steel plate. The methacrylic resin film according to any one of claims 1 to 4 , which is used for building materials or vehicle materials. The laminate according to any one of claims 5 to 9 , which is used for building materials or vehicle materials.