JP2012213911A - Multilayer film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer film which is excellent in external appearance, strength, durability and light resistance and is layered on a base material with excellent adhesion strength without using an adhesive, and to provide another multilayer film obtained by layering a metal on the previously described multilayer film.SOLUTION: The multilayer film is obtained by layering: a first layer formed of a methacrylate-based resin film (I) composed of a methacrylate-based resin composition in which a block copolymer (B) including a polymer block (a) of (meth)acrylic acid alkyl ester and a polymer block (b) of conjugated diene compound exists as a disperse phase in a continuous phase (A) composed of a specific methacrylate-based resin; and a second layer formed of an acrylate-based block copolymer film (II) composed of a composition including an acrylate-based block copolymer (C) having ≥2 polymer blocks (c) each including a (meth)acrylic acid alkyl ester unit and each having ≥50°C Tg, and ≥1 polymer blocks (d) each including a (meth)acrylic acid alkyl ester unit and each having ≤20°C Tg.

Description

  The present invention relates to a multilayer film. Specifically, the present invention relates to a multilayer film formed by laminating a methacrylic resin film and an acrylic block copolymer film. The multilayer film obtained by this invention is useful as an intensity | strength improvement film and a decoration film, for example.

A methacrylic resin film is excellent in appearance and light resistance, and further has improved surface hardness, transparency, and surface smoothness. As a methacrylic resin film, a polymer block composed of a structural unit derived from (meth) acrylate and a conjugated diene A methacrylic resin film made of a resin composition in which a block copolymer having a polymer block composed of a structural unit derived from a compound is dispersed in a methacrylic resin at a specific mass ratio is known. Such a methacrylic resin film is useful for applications requiring high appearance, strength, durability and the like such as building materials and vehicle materials (see Patent Document 1).
In such applications, a multilayer film laminated with a metal is required. However, when a methacrylic resin film is heat-melt bonded to a metal, the adhesive strength is not sufficient, and for example, the methacrylic resin film and the metal may be peeled off due to a difference in expansion coefficient accompanying a temperature change. In addition, when a methacrylic resin film and a metal are bonded together with an adhesive, etc., there are concerns about effects on transparency, appearance, light resistance, etc. in addition to adhesive strength, and an adhesive application process is required. Problems such as a decrease in workability and an increase in defective products become a problem.
In addition, when a metal vapor deposition layer is formed on one side of a methacrylic resin film (for example, by dry or wet film formation (vapor deposition, sputtering, etc.)), the methacrylic resin film has poor adhesion to the metal vapor deposition layer, and it takes. In order to improve the adhesion, an anchor layer made of a thermosetting resin such as polyurethane, melamine, or epoxy is generally formed in advance. However, peeling between the methacrylic resin film and the anchor layer may occur due to a difference in material characteristics between the methacrylic resin film and the anchor layer. Moreover, since the manufacturing process of such a metal vapor deposition film is complicated and expensive, a methacrylic resin film that does not require an anchor layer and is excellent in metal vapor deposition at low cost is required.

JP2009-228000 JP-A-11-335432

  Accordingly, an object of the present invention is to provide a multilayer film that is excellent in appearance, strength, durability, and light resistance and can be multilayered on a substrate with good adhesive strength without using an adhesive. Another object of the present invention is to provide a multilayer film obtained by further laminating a metal on a multilayer film excellent in appearance, strength, durability and light resistance.

According to the invention, the object is
[1]
The continuous phase (A) consisting of 100 parts by mass of a methacrylic resin having a structural unit derived from methyl methacrylate of 50% by mass or more has a glass transition temperature of 23 ° C. or less composed of a structural unit derived from an alkyl (meth) acrylate. 1 to 80 parts by mass of a block copolymer (B) having a polymer block (a) and a polymer block (b) having a glass transition temperature of 0 ° C. or lower composed of structural units derived from a conjugated diene compound A first layer comprising a methacrylic resin film (I) comprising a methacrylic resin composition present as a dispersed phase;
Two or more polymer blocks (c) having a glass transition temperature of 50 ° C. or higher composed of structural units derived from (meth) acrylic acid alkyl ester, and a glass transition temperature composed of structural units derived from (meth) acrylic acid alkyl ester A second layer made of an acrylic block copolymer film (II) made of a composition containing an acrylic block copolymer (C) having at least one polymer block (d) of 20 ° C. or lower; A multilayer film comprising:
[2]
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 of formula (i):
[Number average molecular weight of star block copolymer]> 2 × [Number average molecular weight of arm polymer block] (i)
The multilayer film of [1] that satisfies the above.
[3]
The star block copolymer has the formula (ii):
(Polymer block (b) -polymer block (a)-) nX (ii)
(In the formula, X represents a coupling residue, and n represents a number exceeding 2.)
A multilayer film of the above-mentioned [2] represented by:
[4]
Any one of the above [1] to [3], wherein the mass ratio of the polymer block (c) to the polymer block (d) in the acrylic block copolymer (C) is 20/80 to 80/20 Multilayer film;
[5]
The acrylic block copolymer (C) has the formula (iii):
Polymer block (c) -polymer block (d) -polymer block (c) (iii)
A multilayer film according to any one of the above [1] to [4];
[6]
The multilayer film according to any one of [1] to [5] above, in which a third layer made of metal is further laminated on the second layer; and [7] the third layer made of metal is a metal vapor deposition layer. [6] a multilayer film;
Is achieved by providing

  According to the present invention, it is possible to provide a multilayer film that is excellent in transparency while maintaining appearance, strength, durability, and light resistance, and that can be laminated with a substrate without using an adhesive. In addition, a multilayer film having a high interface strength obtained by laminating a metal on such a multilayer film can be provided.

It is a photograph after the adhesion test when the thickness of the metal layer is 100 Å (Example 1). It is a photograph after an adhesion test when the thickness of the metal layer is 100 Å (Comparative Example 1). Optical micrograph after adhesion test when metal layer thickness is 800 Å (partially enlarged) (Example 5) Optical micrograph after adhesion test when the thickness of the metal layer is 800 Å (partially enlarged) (Comparative Example 2)

Hereinafter, the present invention will be described in more detail.
The multilayer film of the present invention comprises a first layer composed of a methacrylic resin film (I) (hereinafter sometimes simply referred to as “first layer”) and an acrylic block copolymer film (II). Two layers (hereinafter, simply referred to as “second layer”) are laminated.

  The methacrylic resin film (I) used in the present invention has a block copolymer (B) 1 in a continuous phase composed of 100 parts by mass of a methacrylic resin (A) having 50% by mass or more of a structural unit derived from methyl methacrylate. It consists of methacrylic resin composition in which -80 mass parts exists as a dispersed phase.

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

  The weight average molecular weight (Mw) in terms of polystyrene determined by gel permeation chromatography (GPC) measurement of the methacrylic resin (A) is preferably 70,000 to 200,000, more preferably 80,000 to 150,000, particularly preferably. 90,000 to 120,000. When Mw is less than 70,000, the toughness and handleability of the methacrylic resin film tend to decrease. On the other hand, if Mw exceeds 200,000, the fluidity of the methacrylic resin composition is lowered and film formation becomes difficult, and even if film formation is possible, the surface smoothness of the methacrylic resin film (I) tends to decrease. It becomes.

  The methacrylic resin (A) used in the present invention has a weight average molecular weight (Mw) / number average molecular weight (Mn) value (Mw / Mn: molecular weight distribution) determined by GPC, preferably 3.0 or less. More preferably, it is 2.5 or less, and particularly preferably 2.3 or less. If the molecular weight distribution exceeds 3.0, the toughness and film forming property of the methacrylic resin film (I) tend to be lowered. The molecular weight and molecular weight distribution of the methacrylic resin (A) 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 has a glass transition temperature (Tg _a ) composed of structural units derived from (meth) acrylic acid alkyl ester of 23 ° C. or less, preferably 0 ° C. or less, more preferably The polymer block (a) having a temperature of −10 ° C. or lower and a glass transition temperature (Tg _b ) composed of a structural unit derived from a conjugated diene compound is preferably 0 ° C. or lower, more preferably −10 ° C. or lower. (B) The lower the glass transition temperature, the more suitable for use in cold regions.

The structural 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 acryl.
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. Examples thereof include isobutyl and 2-ethylhexyl acrylate. These may be polymerized individually by 1 type, and may be copolymerized combining 2 or more types. From among these, Tg _a gives may be selected a combination of monomers or monomer, Tg _a is 0 ℃ or less of the polymer block (a) providing a 23 ° C. or less of the polymer block (a) the combination of the monomer or monomer is preferred, Tg _a more preferred combination of monomers or monomer giving a -10 ° C. or less of the polymer block (a). As such a monomer, either or both of n-butyl acrylate and 2-ethylhexyl acrylate are preferable, and n-butyl acrylate is more preferable.

The polymer block (b) composed of a structural unit derived from a conjugated diene compound is obtained by addition polymerization of a conjugated diene compound.
Examples of the conjugated diene compound include butadiene, isoprene, pentadiene, and 2,3-dimethylbutadiene. 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 that gives a polymer block (b) having a Tg _b of 0 ° C. or lower may be selected. A polymer block (b) having a Tg _b of −10 ° C. or lower is selected. Preferred monomers or combinations of monomers are given. Further, from the viewpoint of versatility, economy, and handleability, either or both of butadiene and isoprene are preferable, and butadiene is more preferable.

  There are three types of structural units derived from conjugated diene compounds: 1,4-bond units, 1,2-bond units, and 3,4-bond units. The 1,4-bond unit has a carbon-carbon double bond in the molecular main chain. On the other hand, a 1,2-bond unit and a 3,4-bond unit have a vinyl group (side chain vinyl bond) bonded to the molecular main chain. The carbon-carbon double bond and the side chain vinyl bond in the molecular main chain serve as a starting point for a graft reaction or a crosslinking reaction. The proportion of 1,2-bond units and 3,4-bond units can be increased by adding polar compounds such as ethers to the polymerization reaction system.

The amount of side chain vinyl bonds in the polymer block (b) is represented by the ratio [mol%] of 1,2-bond units or 3,4-bond units among the structural units derived from the conjugated diene compound. The amount of the side chain vinyl bond 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 (I). 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 10 mol% to 35 mol%. More preferably it is. When the side chain vinyl bond amount is in the above-described range, transparency, surface smoothness, toughness, flexibility, and the like are improved. In the case of the polymer block (b) consisting of structural units derived from butadiene, the side chain vinyl bond content is 4.7 to 5.2 ppm of chemical shift of the spectrum shown by ¹ H-NMR analysis (hereinafter referred to as signal C _0). The integrated intensity of the protons (= CH ₂ ) of 1,2-vinyl in ( ₂ ) and the vinyl protons (= CH—) of chemical shifts of 5.2 to 5.8 ppm (hereinafter referred to as signal D ₀ ), When the integrated intensity of each signal is represented by C ₀ and D ₀ , respectively, the side chain vinyl bond amount V ₀ [mol%] can be calculated by the following formula (iv).
V ₀ = _{[(C 0/2) / {} C 0/2 + (D 0 -C 0/2) / 2} ] × 100 (iv)

The polymer block (b) may be obtained by partially hydrogenating the carbon-carbon double bond and / or the side chain vinyl bond in the molecular main chain. From the viewpoint of maintaining the effect 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. For example, the method disclosed in Japanese Patent Publication No. 5-20442 , that is, a catalyst obtained by combining an organometallic compound containing titanium as a metal component alone or an organometallic compound such as lithium, magnesium, and aluminum. Is used as a hydrogenation catalyst, the hydrogen partial pressure is 10 kg / cm ² or less, and the reaction can be carried out in a suitable solvent at a reaction temperature of 0 to 100 ° C.

The 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 (I). 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 determined 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) It is preferable that it is 30-65 mass%, and it is more preferable that it is 40-60 mass%. The polymer block (b) is preferably 35 to 70% by mass, more preferably 40 to 60% by 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.
As the binding mode of the block copolymer, an ab type diblock copolymer, an aba type triblock copolymer, a bb type triblock copolymer, an abb a -B-type tetrablock copolymers and linear multi-block copolymers typified by ba-ba-type tetrablock copolymers, (ba-) nX, (ab-) nX ( In the formula, X represents a coupling agent residue, n represents a number exceeding 2) and the like, and a star-shaped (radial star-type) block copolymer, a graft copolymer represented by ag-b Examples include coalescence. Note that 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 constitutional unit composition that gradually changes from the composition of the constitutional unit of the polymer block (a) to the composition of the constitutional 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 1.480 to 1.500, more preferably 1.485 to 1.495. When the refractive index is within this range, the transparency of the methacrylic resin composition is maintained.
The refractive index of the block copolymer (B) can be adjusted by selecting the type of polymer structural unit, the composition ratio, the amount of side chain vinyl bonds in the polymer block (b), and the like. For example, in a diblock copolymer comprising a polymer block (a) composed of a structural unit derived from n-butyl acrylate and an unhydrogenated polymer block (b) composed of a structural unit derived from butadiene, When the content of n-butyl acrylate is 30 to 65% by mass and the content of butadiene is 35 to 70% by mass with respect to the total mass of the copolymer, the refractive index of polymethyl methacrylate substantially coincides with that of transparent methacrylic acid. -Based resin film (I) can be obtained.
In the present invention, the refractive index of the block copolymer (B) is determined by the following method. A solution in which the block copolymer (B) is uniformly dissolved in a toluene solvent so as to be 30% by mass is prepared. The density of the solution and toluene and the refractive index by an Abbe refractometer are measured at room temperature, and the refractive index of the block copolymer (B) is determined using the following formulas (v) to (vii). Further, polymethyl methacrylate having a known refractive index (n _d = 1.492) is measured by the same method, and a calibration coefficient for refractive index measurement by this method is obtained to calibrate the refractive index of the block copolymer (B). Is possible.
[(N _d ² −1) / (n _d ² +2)] × V = r = constant (v)
r ₃ = w ₁ r ₁ + w ₂ r ₂ (vi)
V ₂ = (1 / ρ ₁ ) − (1 / W ₂ ) × [(1 / ρ ₁ ) − (1 / ρ ₃ )] (vii)
[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,
_{Found: V 3, n d3, V} 1, nd 1]
Formula (v), Formula (vi) Source: Polymer Experimental Studies Vol. 12, “Thermodynamic, Electrical and Optical Properties”
Published in 1984 Kyoritsu Publishing Ceremony (vii) Source: Polymer Experiments Vol. 11, “Polymer Solution”, published in 1982 Kyoritsu Publishing

  As the block copolymer (B), a diblock copolymer or a star block copolymer composed of a polymer block composed of a structural unit derived from n-butyl acrylate and a polymer block composed of a structural unit derived from butadiene. Derived from a polymer block consisting of a polymer unit consisting of a unit derived from 2-ethylhexyl acrylate and a polymer block consisting of a unit derived from butadiene, a star block copolymer, derived from methyl methacrylate A triblock copolymer or a star block consisting of a polymer block composed of structural units, a polymer block composed of structural units derived from n-butyl acrylate monomer, and a polymer block composed of structural units derived from butadiene. Examples are polymers.

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.

  If the arm polymer block which comprises a star-shaped block copolymer has a polymer block (a) and a polymer block (b), it will not be restrict | limited by the coupling | bonding aspect. As the arm polymer block, an ab type diblock copolymer, an aba type triblock copolymer, an bb type triblock copolymer, an abba- 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 formula (ii):
(Polymer block (b) -polymer block (a)-) nX (ii)
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. Formula: [Number average molecular weight of star block copolymer]> 2 × [Number average molecular weight of arm polymer block] (i)
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 desired strength is increased and the desired toughness can be obtained. In addition, since the number average molecular weight of the star block copolymer as the block copolymer (B) is larger than 100 times the number average molecular weight of the arm polymer block, it is difficult to synthesize. The number average molecular weight of the copolymer is more than twice and less than 100 times the number average molecular weight of the arm polymer block, more preferably 2.5 to 50 times, still more 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.

It is not specifically limited by the manufacturing method of a block copolymer (B), The method according to a well-known method is applicable. 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 techniques include, for example, living polymerization using an organic rare earth metal complex as a polymerization initiator, presence of an alkali metal or alkaline earth metal mineral salt using an organic alkali metal compound as a polymerization initiator, and the like. Examples thereof include a method of living anion polymerization under the conditions, a method of living anion polymerization in the presence of an organoaluminum compound using an organic alkali metal compound as a polymerization initiator, and an atom transfer radical polymerization (ATRP) method.

  Among the above production methods, the method of living anion polymerization using an organic alkali metal compound as a polymerization initiator in the presence of an organoaluminum compound has a narrower molecular weight distribution and a residual unit weight under a relatively mild temperature condition. It is preferable in that a block copolymer having a small number of bodies can be produced, and environmental burden in industrial production (mainly power consumption of a refrigerator necessary for controlling the polymerization temperature) is small.

  As the organic alkali metal compound used for the living anionic polymerization, an organic lithium compound is suitable. Specific examples of the organic lithium compound include n-butyllithium, sec-butyllithium, isobutyllithium, tert-butyllithium, alkyllithium such as tetramethylenedilithium and alkyldilithium; aryllithium such as phenyllithium and xylyllithium. And aryldilithium; aralkyllithium such as dilithium and aralkyldilithium produced by the reaction of benzyllithium, diisopropenylbenzene and butyllithium; lithium amide such as lithium diisopropylamide; lithium alkoxide such as methoxylithium. These may be used alone or in combination of two or more.

Examples of the organoaluminum compound used in the living anionic polymerization include the following general formula: AlR ¹ R ² R ³ (viii)
(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; 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.)
The organoaluminum compound represented by these is mentioned.
Examples of the organoaluminum compound include isobutyl bis (2,6-di-tert-butyl-4-methylphenoxy) aluminum, isobutyl bis (2,6-di-tert-butylphenoxy) aluminum, isobutyl [2,2′-methylene bis (4-Methyl-6-tert-butylphenoxy)] aluminum is particularly easy in handling and allows the living anion polymerization reaction to proceed without deactivation under relatively mild temperature conditions. preferable.

  In the above living anionic polymerization, ethers such as dimethyl ether, dimethoxyethane, diethoxyethane, 12-crown-4-ether; triethylamine, N, N, N ′, N′-tetramethyl are included in the reaction system as necessary. Nitrogen-containing compounds such as ethylenediamine, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine, 1,1,4,7,10,10-hexamethyltriethylenetetramine, pyridine, 2,2′-dipyridyl May coexist.

The star block copolymer is obtained by adding a polyfunctional monomer to the block copolymer reaction mixture obtained by the above living anion polymerization or the like and copolymerizing it, or reacting the block copolymer. It can be obtained by adding a polyfunctional coupling agent to the mixed solution 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.

  Production of the block copolymer (B) used in the present invention includes aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as chloroform, methylene chloride and carbon tetrachloride; ethers such as tetrahydrofuran and diethyl ether. A living anionic polymerization method using an organic alkali metal compound as a polymerization initiator in an inert gas atmosphere such as nitrogen, argon, helium or the like in a solvent inert to the polymerization reaction is preferable.

  The method for producing the block copolymer (B) by living anionic polymerization is further specifically exemplified. For example, after the monomer for forming the polymer block (b) is polymerized with a polymerization initiator composed of an organic alkali metal compound and it is confirmed that the polymer block (b) having a desired molecular weight is obtained, the reaction mixture Is cooled to the desired temperature and an organoaluminum compound is added. Subsequently, the monomer which forms a polymer block (a) is added, it superposes | polymerizes, and a desired polymer block (b) -polymer block (a) (the living polymer terminal is a polymer block (a)) is obtained. . In the case of producing a star block copolymer, a polyfunctional monomer such as 1,6-hexanediol diacrylate or a polyfunctional coupling agent is further added to the reaction system and reacted. By reacting the active terminal with alcohol or the like, a star block copolymer having the polymer block (b) -polymer block (a) as an arm polymer block can be produced.

  The methacrylic resin composition used in the present invention is 1 to 80 parts by mass, preferably 2 to 30 parts by mass, and more preferably 4 to 100 parts by mass of the methacrylic resin (A). It is contained at ~ 20 parts by mass. When the content of the block copolymer (B) is less than 1 part by mass, the effect of improving the toughness of the methacrylic resin film (I) is small. When there are many block copolymers (B), it will become difficult for a block copolymer (B) to form a dispersed phase. Moreover, the surface hardness and rigidity of the methacrylic resin film (I) are lowered. 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 the surface smoothness tend to decrease.

  The dispersed phase comprising the block copolymer (B) includes a sea phase composed of a sea phase composed of the block copolymer (B) and an island phase composed of the methacrylic resin (A). Is preferred. 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 with a transmission electron microscope. Can be confirmed by.

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 its 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 with a uniaxial or biaxial melt extruder or the like. However, in the present invention, the block copolymer (B) is dissolved in a monomer mixture (Am) containing 50% by mass or more of methyl methacrylate, and the monomer mixture (Am) is polymerized under shear. It is preferable to obtain by a method in which the solution phase of the polymer of the monomer mixture (Am) and the solution phase of the block copolymer (B) are reversed during the polymerization.

A preferred method for producing the methacrylic resin composition will be described in detail. First, the block copolymer (B) is a monomer mixture (A _m ) composed of 50 to 100% by mass of methyl methacrylate and 0 to 50% by mass of another vinyl monomer copolymerizable with methyl methacrylate. And it melt | dissolves in a solvent (E) as needed, and prepares a raw material liquid.

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 (E) used in the present invention comprises 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 can be mentioned. 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 1 to 80 parts by mass, preferably 2 to 30 parts by mass, more preferably 4 to 100 parts by mass with respect to 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 (I) 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 (I) is lowered, and the excellent rigidity of 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 (E) can be used as needed.

The quantity of the solvent (E) 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 greater the amount of solvent (E), the lower the viscosity of the raw material solution and the better the handleability, but on the other hand, it may cause side reactions such as chain transfer reactions, which may inhibit the graft reaction and cross-linking reaction, resulting in increased productivity. It 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.

  Examples of radical polymerization initiators include 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) ) Organic peroxides such as cyclohexane and t-hexylperoxyisopropyl monocarbonate. These radical polymerization initiators may be used alone or in combination of two or more. Further, the addition timing and addition method of the radical polymerization initiator are not particularly limited as long as the predetermined polymerization reaction proceeds, but the pre-stage polymerization is performed with the radical polymerization initiator charged at the start of the polymerization, It is preferable to add a radical polymerization initiator and perform post-stage polymerization.

  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- Examples include methylstyrene dimer; terpinolene. 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 ) proceeds mainly to produce a methacrylic resin (A). As the polymerization conversion rate increases, the proportion of the solution phase of the methacrylic resin (A) produced by the polymerization of the monomer mixture (A _m ) increases, and the solution phase of the methacrylic resin (A) and the block copolymer ( The solution phase of B) is phase-separated.

Along with the progress of the polymerization reaction, the action to stabilize the whole phase works. By the shearing force by stirring, the solution phase of the methacrylic resin (A) and the solution phase of the block copolymer (B) are phase-inverted. The solution phase of the methacrylic resin (A) 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 (A) to the solution phase of the block copolymer (B), the block copolymer ( The molecular weight of B), the graft ratio to the block copolymer (B) before phase inversion, and when a solvent is used vary 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 the 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 becomes insufficient. 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.

  In addition, the presence or absence of the disperse phase production comprising the block copolymer (B) during the polymerization and the diameter of the disperse phase were obtained by extracting a part of the reaction mixture during the polymerization and subjecting it to suspension polymerization. A method of observing the morphology of the methacrylic resin composition with a scanning electron microscope, or removing a part of the reaction mixture in the middle of polymerization, drying it, and removing the unreacted monomer and solvent by devolatilization, The morphology of the composition 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. Particularly in the adiabatic flash system, devolatilization is preferably performed at a temperature of 200 to 300 ° C, more preferably 220 to 270 ° C. Below 200 ° C., devolatilization takes time, and when devolatilization is insufficient, appearance defects such as silver may occur in the methacrylic resin film (I). On the other hand, when the temperature exceeds 300 ° C., the methacrylic resin film (I) 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 (I).

  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. The methacrylic resin composition can also be used after being diluted with an industrially available methacrylic resin (F). Moreover, it can also be used by mixing with other resins such as AS resin, ABS resin, AES resin, AAS resin, MS resin, MBS resin, styrene resin, high impact polystyrene resin, vinyl chloride resin.

  The methacrylic resin (F) used for diluting the methacrylic resin composition as necessary is composed of 80% by mass or more of structural units derived from methyl methacrylate and a vinyl monomer copolymerizable with methyl methacrylate. The unit is composed of 20% by mass or less. 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 esters such as benzyl acrylate; ethyl methacrylate, butyl methacrylate, propyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, phenyl methacrylate, benzyl methacrylate, etc .; vinyl acetate; styrene, p-methyl Aromatic vinyl compounds such as styrene, o-methylstyrene, m-methylstyrene, α-methylstyrene, vinylnaphthalene; nitriles such as acrylonitrile and methacrylonitrile; acrylic acid, methacrylic acid, crotonic acid Of alpha, beta-unsaturated carboxylic acid; N- ethylmaleimide, maleimide compounds such N- cyclohexyl maleimide. These vinyl monomers can be used alone or in combination of two or more.

  The intrinsic viscosity of the methacrylic resin (F) is preferably 0.3 to 1.0 dl / g. When the intrinsic viscosity of the methacrylic resin (F) is less than 0.3, the viscosity when the resulting methacrylic resin composition is melt-molded 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. When mix | blending a methacryl resin (F), the compounding quantity becomes like this. Preferably it is 1-100 mass parts with respect to 100 mass parts of methacrylic-type resin compositions, More preferably, it is 5-70 mass parts. When the blending amount of the methacrylic resin (F) exceeds 100 parts by mass, the handleability of the resulting methacrylic resin film (I) tends to be lowered.

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

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

The methacrylic resin film (I) used in the present invention can be obtained by film-forming the methacrylic resin composition. As the 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, but an extrusion forming method using a T die is preferable from the viewpoint of economy.
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 (I) 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 (I) used in the present invention, it is melted from the viewpoint that a methacrylic resin film (I) having good surface smoothness, good specular gloss and low haze can be obtained. A method comprising a step of extruding a methacrylic resin composition in a molten state from a T-die and forming both sides of the extruded product in contact with a mirror roll surface or a mirror belt surface is preferred. 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 the mirror belt is preferably high, and the linear pressure is preferably 10 N / mm or more, and more preferably 30 N / mm or more.

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

  The resin temperature in the extrusion molding method is preferably 160 to 260 ° C, more preferably 220 to 250 ° C. After the melt molding, the methacrylic resin film (I) is preferably cooled more rapidly than natural cooling. For example, it is preferable that the methacrylic resin film (I) immediately after being formed is brought into contact with a cooling roll and rapidly cooled. 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 (I) used in 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 (I) used in the present invention is usually 300 μm or less, preferably 30 to 300 μm, more preferably 50 to 200 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 (I) used in 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 surface of the methacrylic resin film (I) used in 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 higher. Harder than. It is preferable to use a methacrylic resin film having a hard surface because the surface hardness of the laminated film of the present invention is also increased.

  The methacrylic resin film (I) 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 methacrylic resin film (I) is immersed in a liquid in which a dye is dispersed. Although the dyeing | staining method etc. which are colored are mentioned, it is not specifically limited.

  The acrylic block copolymer film (II) used in the present invention consists of a resin composition containing the acrylic block copolymer (C).

  The acrylic block copolymer constituting the acrylic block copolymer film (II) used in the present invention is a polymer block having a glass transition temperature of 50 ° C. or higher comprising a structural unit derived from a (meth) acrylic acid alkyl ester. 2 or more of (c) and 1 or more polymer blocks (d) having a glass transition temperature of 20 ° C. or less composed of structural units derived from alkyl (meth) acrylate. The composition containing such an acrylic block copolymer (C) has excellent melt processability, and the acrylic block copolymer film (II) formed from the composition has flexibility, light resistance, and transparency. Excellent.

The structural unit derived from the (meth) acrylic acid alkyl ester constituting the polymer block (c) is obtained by addition polymerization of a (meth) acrylic acid alkyl ester.
For example, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, phenyl methacrylate, 2-hydroxyethyl methacrylate, etc. Methacrylic acid ester; acrylic acid ester such as methyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, isobornyl acrylate, phenyl acrylate, 2-hydroxyethyl acrylate, and the like.

  Among these, from the viewpoint of improving the transparency and heat resistance of the resulting acrylic block copolymer film (II), methyl methacrylate, ethyl methacrylate, tert-butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, Preferred are isobornyl methacrylate, phenyl methacrylate, 2-hydroxyethyl methacrylate, methyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, isobornyl acrylate, phenyl acrylate, 2-hydroxyethyl acrylate, and methyl methacrylate. More preferred. The polymer block (c) may be synthesized from one of these methacrylic acid esters and acrylic acid esters, or may be synthesized from two or more kinds. The acrylic block copolymer (C) contains two or more polymer blocks (c), and these polymer blocks (c) may be the same or different.

  Examples of the monomer used for the synthesis of the polymer block (d) include n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, Methacrylic acid esters such as 2-ethylhexyl methacrylate, pentadecyl methacrylate, dodecyl methacrylate, phenoxyethyl methacrylate, 2-methoxyethyl methacrylate; methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, acrylic N-butyl acid, isobutyl acrylate, sec-butyl acrylate, amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, pentadecyl acrylate, dodecyl acrylate , Benzyl acrylate, phenoxyethyl acrylate, and the like 2-methoxyethyl acrylate.

Among these, from the viewpoint of improving the flexibility of the resulting acrylic block copolymer film (II) and the followability to the methacrylic resin film (I), methyl acrylate, ethyl acrylate, isopropyl acrylate, acrylic Acrylic acid esters such as n-butyl acid, 2-ethylhexyl acrylate, dodecyl acrylate, phenoxyethyl acrylate, and 2-methoxyethyl acrylate are preferred.
The polymer block (d) may be synthesized from one of these methacrylic acid esters and acrylic acid esters, or may be synthesized from two or more kinds. When the acrylic block copolymer (C) includes two or more polymer blocks (d), the polymer blocks (d) may be the same or different.

  As long as the properties of the acrylic block copolymer (C) used in the present invention are not impaired, the monomer used for the synthesis of the polymer block (c) and the polymer block (d) further has a reactive group. (Meth) acrylic acid esters may be used. Examples of the (meth) acrylic acid ester having a reactive group include glycidyl methacrylate, allyl methacrylate, glycidyl acrylate, and allyl acrylate. These are usually used in small amounts, but are preferably used in an amount of 40% by mass or less, more preferably 20% by mass or less, based on the total mass of monomers used for the synthesis of each polymer block.

  Moreover, as a monomer used for the synthesis | combination of the said polymer block (c) and a polymer block (d) in the range which does not impair the characteristic of the acrylic type block copolymer (C) used for this invention as needed. Other monomers may be used in combination.

  Examples of such other monomers include methacrylic acid, acrylic acid, styrene, α-methylstyrene, p-methylstyrene, m-methylstyrene, acrylonitrile, methacrylonitrile, ethylene, propylene, isobutene, butadiene, isoprene, octene. Vinyl acetate, maleic anhydride, vinyl chloride, vinylidene chloride and the like. When these monomers are used, they are usually used in a small amount, but preferably 40% by mass or less, more preferably 20% by mass or less, based on the total mass of monomers used for the synthesis of each polymer block. Use in quantity.

The acrylic block copolymer (C) used in the present invention may have other polymer blocks as necessary in addition to the polymer block (c) and the polymer block (d).
Examples of other polymer blocks include methacrylic acid, acrylic acid, styrene, α-methylstyrene, p-methylstyrene, m-methylstyrene, acrylonitrile, methacrylonitrile, ethylene, propylene, isobutene, butadiene, isoprene, octene. Polymer block or copolymer block synthesized from monomers such as vinyl acetate, maleic anhydride, vinyl chloride, vinylidene chloride; polymer comprising polyethylene terephthalate, potylene terephthalate, polylactic acid, polyurethane, polydimethylsiloxane Examples include blocks. The polymer block also includes a hydrogenated polymer block synthesized from a monomer containing a conjugated diene such as butadiene or isoprene.

  The bonding form of the polymer block contained in the acrylic block copolymer (C) of the present invention is not particularly limited, but the form in which the polymer block (c) is bonded to both ends of at least one polymer block (d). It is preferable from the viewpoints of heat resistance, mechanical strength, surface sticking, and the like of the acrylic block copolymer film (II) of the present invention. Examples of the copolymer include a triblock copolymer of polymer block (c) -polymer block (d) -polymer block (c), polymer block (c) -polymer block (d)- Examples thereof include a tetrablock copolymer of polymer block (c) -polymer block (d). Among these, a triblock copolymer of polymer block (c) -polymer block (d) -polymer block (c) is more preferable from the viewpoint of easy production and less surface sticking.

The glass transition temperatures of the polymer block (c) and the polymer block (d) in the present invention are those observed in a curve obtained by analyzing the acrylic block copolymer (C) with a differential scanning calorimeter (DSC). It is the extrapolation start temperature (Tgi) of the transition region of the merged block (c) and the polymer block (d). As a specific measuring method, the method detailed in the item of the following Example is employ | adopted. Based on the curve obtained by the DSC measurement, the acrylic block copolymer (C) used in the present invention requires a plurality of glass transition temperatures derived from the polymer block (c) and the polymer block (d). . The glass transition temperature derived from the polymer block (c) and the polymer block (d) is the same as the glass transition temperature of the polymer having the same chemical structure (monomer composition, stereoregularity, etc.) as each polymer block. Therefore, it can be easily determined which polymer block these glass transition temperatures are derived from. The polymer having the same chemical structure as the polymer block (c) and the polymer block (d) is obtained by analyzing the acrylic block copolymer (C) by ¹ H-NMR, ¹³ C-NMR, etc. The chemical structure such as the monomer composition and stereoregularity of the polymer block (c) and the polymer block (d) is obtained, and the polymer structure is appropriately polymerized so that the chemical structure is reproduced.

  The molecular weight of the acrylic block copolymer (C) is not particularly limited, but from the viewpoint of moldability of the acrylic block copolymer film (II) of the present invention, the weight average molecular weight in terms of polystyrene determined by GPC measurement is It is preferable that it is 10,000-500,000, and it is more preferable that it is 20,000-300,000.

  Examples of the molding method of the acrylic block copolymer film (II) of the present invention include a melt extrusion molding method, a melt injection molding method, a solution casting method, and the like. To a weight average molecular weight within the above range is preferred.

  The molecular weight distribution of the acrylic block copolymer (C) has a weight average molecular weight / number average molecular weight value from the viewpoint of the adhesiveness and transparency of the surface of the acrylic block copolymer film (II) of the present invention. It is preferable that it is 1.01-2.20, and it is more preferable that it is 1.05-1.60. When the molecular weight distribution is larger than the above range, there may be a disadvantage that the high molecular weight is increased and the transparency is impaired, or the low molecular weight component is increased and the surface sticking becomes severe. In addition, when the molecular weight distribution is smaller than the above range, the composition ratio of the low molecular weight component that favorably affects the moldability and the high molecular weight component that favorably contributes to the mechanical properties becomes small. The mechanical properties required for the system block copolymer film (II) may be impaired.

  The acrylic block copolymer (C) has a functional group such as a hydroxyl group, a carboxyl group, an acid anhydride group, an amino group, or a trimethoxysilyl group in the molecular chain or at the molecular chain end as necessary. May be.

  Since the acrylic block copolymer film (II) of the present invention requires particularly excellent light transmittance depending on the application, the acrylic block copolymer (C) needs to be excellent in transparency. is there. Specifically, the total light transmittance of a sheet having a thickness of 3 mm obtained from the acrylic block copolymer (C) is preferably 88% or more, and more preferably 90% or more.

  The acrylic block copolymer (C) preferably has the optical characteristics described above. In order to have such optical properties, the acrylic block copolymer (C) preferably has a narrow molecular weight distribution, and a method for producing such a high-purity acrylic block copolymer (C) Is preferably a living polymerization method capable of highly controlling the molecular structure.

  As a method for producing the acrylic block copolymer (C) used in the present invention, a method of living anion polymerization using an organic alkali metal compound as a polymerization initiator in the presence of an organic aluminum compound is preferable (see Patent Document 2). .

As the organic alkali metal compound used in the living anionic polymerization, an organic lithium compound is suitable.
Specific examples of the organic lithium compound include n-butyllithium, sec-butyllithium, isobutyllithium, tert-butyllithium, alkyllithium such as tetramethylenedilithium and alkyldilithium; aryllithium such as phenyllithium and xylyllithium. And aryldilithium; aralkyllithium such as dilithium and aralkyldilithium produced by the reaction of benzyllithium, diisopropenylbenzene and butyllithium; lithium amide such as lithium diisopropylamide; lithium alkoxide such as methoxylithium. These may be used alone or in combination of two or more.

Examples of the organoaluminum compound used in the above living anionic polymerization include the following general formula:
AlR ¹ R ² R ³ (viii)
(In the formula, R ¹ , R ² and R ³ each independently has an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, or a substituent. An aryl group which may have a substituent, 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.
The organoaluminum compound represented by these is mentioned.
Examples of the organoaluminum compound include isobutyl bis (2,6-di-tert-butyl-4-methylphenoxy) aluminum, isobutyl bis (2,6-di-tert-butylphenoxy) aluminum, isobutyl [2,2′-methylene bis (4-Methyl-6-tert-butylphenoxy)] aluminum is particularly preferred in that it is easy to handle and allows the anionic polymerization reaction to proceed without deactivation under relatively mild temperature conditions. .

  In the above living anionic polymerization, if necessary, an ether such as dimethyl ether, dimethoxyethane, diethoxyethane, 12-crown-4-ether; triethylamine, N, N, N ′, N′-tetra, Nitrogen-containing compounds such as methylethylenediamine, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine, 1,1,4,7,10,10-hexamethyltriethylenetetramine, pyridine, 2,2′-dipyridyl, etc. A compound can further coexist.

  The living anion polymerization is usually performed in the presence of a solvent inert to the polymerization reaction. Examples of such solvents include hydrocarbon solvents such as benzene, toluene, and xylene; halogenated hydrocarbons such as chloroform, methylene chloride, and carbon tetrachloride; ethers such as tetrahydrofuran and diethyl ether. Regarding the polymerization temperature and polymerization time of the anionic polymerization, from the viewpoint of suppressing the deactivation of the polymerization reaction, −30 to 20 ° C. and 10 seconds to 20 hours are preferable, from the viewpoint of cooling efficiency and physical properties of the obtained block copolymer − More preferably, the temperature is about 20 to 10 ° C. and about 1 minute to 10 hours.

  The method for producing the acrylic block copolymer (C) by living anionic polymerization in the presence of an organoaluminum compound is further specifically exemplified. For example, a first step of polymerizing a monomer that forms a polymer block (c) with a polymerization initiator composed of an organic alkali metal compound in the presence of an organoaluminum compound, a single amount that forms a polymer block (d) The acrylic block copolymer can be produced through three or more polymerization steps including a second step of polymerizing the polymer and a third step of polymerizing the monomer forming the polymer block (c).

  In the said manufacturing method, a desired polymer block will be formed at the living polymer terminal produced | generated at each process at the next process. Therefore, for example, the polymer block (c) -polymer block is obtained by continuously reacting the active terminal of the obtained polymer with alcohol or the like through the above three-step polymerization process and stopping the polymerization reaction. A ternary block copolymer comprising (d) -polymer block (c) can be produced. Here, the quaternary or more block copolymer is obtained by further polymerizing monomers after the above-described three-stage process (polymer block (c), polymer block (d), etc.). Can be produced by adding the desired number of steps, reacting the active terminal of the polymer obtained with alcohol or the like, and stopping the polymerization reaction.

The composition ratio (polymer block (c) / polymer block (d)) of the polymer block (c) and the polymer block (d) of the acrylic block copolymer is 20/80 to 80 / as a mass ratio. 20 is preferable, and 30/70 to 70/30 is more preferable. When the composition ratio of the polymer block (c) / polymer block (d) is smaller than the above range, the adhesion may be severe and the surface property may be impaired due to scratches or dust adhesion. There are cases where the shape retention of the copolymer film (II) is deteriorated and the handleability is lowered. When the composition ratio of the polymer block (c) / polymer block (d) is larger than the above range, the flexibility of the acrylic block copolymer tends to be insufficient.
Moreover, it is preferable to exist in the range of 80 / 20-20 / 80 from a viewpoint of improving the adhesive force with the layer of the metal compound mentioned later.

  The composition used for the acrylic block copolymer film (II) used in the present invention contains the acrylic block copolymer (C) as an essential component. Moreover, 1 type of the said acrylic block copolymers (C) may be contained in this composition, and 2 or more types may be contained.

  The content of the acrylic block copolymer (C) in the composition is not particularly limited as long as the effect of the present invention is not impaired, but is 30% by mass to 100% with respect to the total mass of the composition. It is preferable that it is mass%, and it is more preferable that it is 50 mass%-100 mass%.

  In the above composition, other polymers, softeners, lubricants, plasticizers, pressure-sensitive adhesives, tackifiers, heat stabilizers, antioxidants, light stabilizers, electrifiers, etc., as long as the effects of the present invention are not impaired. Additives such as an inhibitor, a flame retardant, a foaming agent, a colorant, a dyeing agent, and a filler may be included. One or more of these other polymers and additives may be contained in the composition, or two or more of them may be contained.

  Examples of such other polymers include acrylic resins (G) such as polymethyl methacrylate and methacrylate ester copolymers; polyethylene, ethylene-vinyl acetate copolymers, polypropylene, polybutene-1, and poly-4-methylpentene. -1, Olefin resins such as polynorbornene; Ethylene ionomer; Styrene such as polystyrene, styrene-maleic anhydride copolymer, high impact polystyrene, AS resin, ABS resin, AES resin, AAS resin, ACS resin, MBS resin Resin; methyl methacrylate-styrene copolymer; polyester resin such as polyethylene terephthalate, polybutylene terephthalate, polylactic acid; polyamide such as nylon 6, nylon 66, polyamide elastomer; polycarbonate, polyvinyl chloride Polyvinylidene chloride, polyvinyl alcohol, ethylene - vinyl alcohol copolymer, polyacetal, polyvinylidene fluoride, polyurethanes, modified polyphenylene ether, polyphenylene sulfide, and the like silicone rubber-modified resins. Among these, acrylic resin (G), ethylene-vinyl acetate copolymer, AS resin, polylactic acid, and polyvinylidene fluoride are preferable from the viewpoint of compatibility with the acrylic block copolymer contained in the composition. When these other polymers are included, they may be included alone or in combination of two or more.

  From the viewpoint of improving the transparency, molding processability and the like of the acrylic block copolymer film (II) used in the present invention, it is preferable to contain the acrylic resin (G) among the other polymers. The acrylic resin (G) is composed of 80% by mass or more of structural units derived from methyl methacrylate and 20% by mass or less of structural units derived from a vinyl monomer copolymerizable with methyl methacrylate. 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 Acrylic esters such as benzyl; methacrylates such as ethyl methacrylate, butyl methacrylate, propyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate; vinyl acetate; styrene, p-methylstyrene, Aromatic vinyl compounds such as o-methylstyrene, m-methylstyrene, α-methylstyrene and vinylnaphthalene; nitriles such as acrylonitrile and methacrylonitrile; α, such as acrylic acid, methacrylic acid and crotonic acid β-unsaturated carboxylic acid; maleimide compounds such as N-ethylmaleimide and N-cyclohexylmaleimide. These vinyl monomers can be used alone or in combination of two or more. Among these, a copolymerizable vinyl monomer from the viewpoint of compatibility with the acrylic block copolymer (C), and transparency and molding processability of the acrylic block copolymer film (II). Is preferably a methacrylic ester such as ethyl methacrylate, butyl methacrylate, propyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, etc., and one or two of these methacrylate esters More than seeds can be used.

When the acrylic resin (G) is a copolymer, the form of copolymerization is not particularly limited, and random copolymerization, block copolymerization, alternating copolymerization, and the like are generally used.
Although there is no restriction | limiting in particular in the intrinsic viscosity of an acrylic resin (G), It is preferable that it is 0.3-1.0 dl / g. Moreover, although an acrylic resin (G) can be used individually by 1 type, the mixture of 2 or more types of acrylic resins (G) from which intrinsic viscosity differs can also be used.

  As long as the acrylic resin (G) used in the present invention satisfies the above conditions, it is generally commercially available as an acrylic resin, and ISO 8257-1: 1997 (E) “plastic-poly (methyl methacrylate) (PMMA) molding and Includes materials specified in "Plastics-Poly (Methyl Methacrylate) (PMMA) molding and extrusion material-"). Examples of such commercially available acrylic resins include “Parapet H1000B”, “Parapet GF”, “Parapet EH”, “Parapet HR-L” and “Parapet G” [all trade names, manufactured by Kuraray Co., Ltd.]. Can be mentioned.

  There is no restriction | limiting in particular in the manufacturing method of an acrylic resin (G), Well-known polymerization methods, such as emulsion polymerization, suspension polymerization, block polymerization, and solution polymerization, are employable.

  From the viewpoint of improving the surface smoothness and maintaining flexibility of the acrylic block copolymer film (II) used in the present invention, the mass ratio of the acrylic block copolymer (C) and the acrylic resin (G) [( C) / acrylic resin (G)] is preferably 100/0 to 20/80, and more preferably 100/0 to 40/60.

The composition containing the acrylic block copolymer (C) used in the present invention is excellent in colorability and dyeability, can give a desired color to the resulting multilayer film, and has a aesthetic feeling. Obtainable.
Examples of the coloring component include conventionally known dyes and pigments that are uniformly dispersed in a methacrylic resin and are colored. Examples of the dye include anthraquinone compounds, phthalocyanine compounds, perinone compounds, dioxazine compounds, benzofuran compounds, thiophene monoazo compounds, cyanine compounds, and diimmonium compounds. Specific examples of anthraquinone compounds include "Diaresin (registered trademark) Black B", "Diaresin (registered trademark) Blue N", "Diaresin (registered trademark) Red K" manufactured by Mitsubishi Chemical Corporation, and Sumika Chemtex Co., Ltd. "Sumiplast (registered trademark) Black H3B", "Sumiplast (registered trademark) Red HFG", "Sumiplast (registered trademark) Violet RR", "Plastread 8320" manufactured by Arimoto Chemical Industry, "Macrolex" manufactured by LANXESS (Registered Trademark) Red 5BFG "," Macrolex (Registered Trademark) Violet 3RFG "," Macrolex (Registered Trademark) Green 5BFG ", and the like. Specific examples of the phthalocyanine compounds include Dainippon Ink & Chemicals, Inc. "Fanstogen Blue RRFG", manufactured by BASF Japan Heliogen Green K-8730 "and the like. Specific examples of perinone compounds include" Diaresin (registered trademark) Orange HS "," Diaresin (registered trademark) Red HS "," Diaresin (registered trademark) "manufactured by Mitsubishi Chemical Corporation. ) Red A ”,“ Macrolex (registered trademark) Orange 3G Gran ”manufactured by LANXESS,“ Macrolex (registered trademark) Red EG Gran ”,“ Sumiplast (registered trademark) Red H3G ”manufactured by Sumika Chemtex, etc. Can be mentioned.

  Examples of the pigment include ultramarine, mica, carbon black, iron oxide, titanium oxide, barium sulfate, calcium carbonate, aluminum hydroxide, titanium yellow, crosslinked polystyrene particles, and silicon particles. Specific examples include “Ultramarine # 1500” manufactured by Daiichi Kasei Co., “Iriodin (registered trademark) 7219 Ultra Lilac” manufactured by Merck Japan, “Iriodin (registered trademark) 153 Flash Pearl”, manufactured by Mitsubishi Chemical Corporation. “Carbon Black MCF88”, “Fine Coal Carbon Black N-29” manufactured by Sanyo Dye Co., Ltd., “Fine Coal Brown TG834”, “Baiferox (registered trademark) 110M” manufactured by LANXESS, “ AD barium sulfate ”,“ Lumipearl DSN-30 ”manufactured by Nemoto Special Chemical Co., Ltd., and the like.

  These other polymers and additives may be added when the composition is molded to produce the acrylic block copolymer film (II).

  Since the composition is used as the acrylic block copolymer film (II), it requires particularly excellent light transmittance depending on the application. Specifically, the total light transmittance of a sheet having a thickness of 3 mm obtained from the composition is preferably 88% or more, and more preferably 90% or more.

  The composition containing the acrylic block copolymer (C) used for the acrylic block copolymer film (II) requires an elastic modulus and flexibility that can maintain its form when used as a film. Become. Therefore, the acrylic block copolymer (C) preferably has a tensile elastic modulus at 25 ° C. of 100 MPa to 2500 MPa, and more preferably 200 MPa to 2000 MPa.

  The thickness of acrylic block copolymer film (II) used by this invention is 300 micrometers or less normally, Preferably it is 10-300 micrometers, More preferably, it is 25-200 micrometers. When the thickness is less than 300 μm, the flexibility is excellent, and the laminating property and secondary workability are good.

  The manufacturing method of acrylic block copolymer film (II) used for this invention can be shape | molded by the method similar to the said methacrylic resin film (I).

(Multilayer film)
The multilayer film of the present invention is obtained by laminating a first layer made of a methacrylic resin film (I) obtained by the above-described manufacturing method and a second layer made of an acrylic block copolymer film (II). can get.
The multilayer film of the present invention is usually used by disposing the first layer as the outermost layer on the surface of various articles described later.
The thickness of the multilayer film of the present invention is preferably 40 to 600 μm, and more preferably 75 to 400 μm. The thickness ratio [(I) / (II)] of the methacrylic resin film (I) and the acrylic block copolymer film (II) is preferably 30/1 to 1/10, and 8/1. More preferably, it is -1/2. Within the above range, it is easy to obtain a multilayer film excellent in processability, and it is easy to suppress peeling between the film and various base materials generated due to the difference in expansion coefficient accompanying temperature change.

  The multilayer film of the present invention is prepared by separately preparing the methacrylic resin film (I) and the acrylic block copolymer film (II), and laminating them continuously between heating rolls. A method of pressure bonding, a method of laminating at the same time as pressure forming or vacuum forming; a method of casting a melted composition containing an acrylic block copolymer (C) on a methacrylic resin film (I); a methacrylic resin composition And a method comprising coextruding an acrylic block copolymer (C) and a composition containing the acrylic block copolymer (C).

The thermocompression bonding between the methacrylic resin film (I) and the acrylic block copolymer film (II) 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.
Further, the methacrylic resin film (I) is placed in a mold or the like, and a composition containing the melted acrylic block copolymer (C) is poured onto the methacrylic resin film (I) to obtain an acrylic resin. A multilayer film can be obtained simultaneously with the formation of the block copolymer film (II).

  In the production by the coextrusion method, a melted methacrylic resin composition and a melted composition containing an acrylic block copolymer (C) are used for coextrusion such as a feed block system or a multi-manifold system. Pour into dies and extrude each at the same time. Each temperature of the melted methacrylic resin composition and the melted composition containing the acrylic block copolymer (C) includes the methacrylic resin composition and the acrylic block copolymer (C). It adjusts suitably so that disorder of the interface with a composition may decrease. The composition containing the coextruded acrylic block copolymer (C) is in contact with the mirror roll surface or the mirror belt surface on both surfaces, as described in the description of the production of the methacrylic resin film (I). Preferably, the method includes a step of forming by molding. The temperature and linear pressure of the mirror roll surface or the mirror belt surface can be selected as appropriate, but it is preferable that the condition range described in the description of the production of the methacrylic resin film (I) is good surface smoothness, good mirror surface It is preferable at the point which can obtain the multilayer film of glossiness and a low haze.

The multilayer film of the present invention includes a laminate obtained by laminating a third layer composed of various base materials (hereinafter sometimes simply referred to as “third layer”) on the second layer. That is, in such a multilayer film, the first layer, the second layer, and the third layer are laminated in this order. Examples of the third layer include resin molded products; metals; wood boards; fiber porous bodies such as woven fabrics and nonwoven fabrics; and ceramics such as glass. When laminated, the acrylic block copolymer film (II) and the acrylic block copolymer film (II) have excellent thermal adhesiveness and excellent compatibility with various substrates. Therefore, it is possible to perform lamination by heat-melt adhesion without using an adhesive.
Examples of the method of laminating the third layer on the second layer include a method of laminating continuously with a heating roll, a method of thermocompression bonding with a press, a method of laminating simultaneously with compressed air or vacuum forming, and the like.

  The multilayer film of the present invention in which various substrates are laminated on the second layer has excellent appearance, strength, and durability. Since the multilayer film of the present invention can be bonded to the base material without using an adhesive by heat-melting and bonding the second layer to the base material, the appearance of the multilayer film due to the adhesive is deteriorated and the light resistance is reduced. In addition, since an adhesive application step is unnecessary, productivity is high. Further, due to the flexibility of the second layer, it is possible to suppress the occurrence of peeling between the laminated film and the substrate based on the difference in the expansion coefficient accompanying the temperature change.

Of the base materials forming the third layer, metal is preferable because of its high adhesive strength with the second layer. Since such a multilayer film can give a metallic luster to the surfaces of various articles described later, it is excellent in aesthetics and can be improved in strength. Moreover, this multilayer film can provide electroconductive performance, visible light reflective performance, infrared reflective performance, and gas barrier performance depending on the kind of metal layer. As a method of laminating the third layer made of metal on the second layer, a method of depositing a metal such as a vacuum deposition method or a sputtering method; an ion plating method; a plating method; And a method of heat-bonding them in layers.
When the third layer made of metal is laminated on the second layer, the acrylic block copolymer film (II) is excellent in adhesiveness with various metals, so an adhesive is used, polyurethane, melamine, epoxy, A multi-layer film having high interface strength can be obtained without forming an anchor layer made of a thermosetting resin. By not using an adhesive or an anchor layer, the work process is simplified, and generation of defective products due to contamination by the adhesive or the anchor layer can be suppressed.

  The above metals include metals such as aluminum, chromium, nickel, gold, silver, copper, germanium, zinc oxide, silicon oxide, magnesium fluoride, tin oxide, ITO, and alloys thereof, depending on the desired metallic luster color. Alternatively, a metal-containing compound can be used.

  The thickness of the metal film depends on the performance expected of the metal used, but is preferably 1000 angstroms or less, more preferably 10 to 800 angstroms or less. When the thickness exceeds 1000 angstroms, the film thickness increases and the adhesion tends to decrease.

  The multilayer film of the present invention may contain a colorant. In this case, the colorant is preferably contained in the second layer in order to improve the appearance of the multilayer film. When the multilayer film includes the third layer, it is possible to realize an appearance that is colored with a desired color even if it is difficult to color the base material constituting the third layer. For example, when the third layer is made of a metal, it is possible to achieve both a desired color and a glossy feeling without changing the metal species and blending or performing special processing. As a method for containing the colorant in the second layer, it is preferable to laminate the acrylic block copolymer film (II) containing the colorant in advance to form the second layer.

  The multilayer film of the present invention is characterized by the excellent transparency, surface smoothness, surface hardness, resistance to warm water whitening and good appearance (low blister) of the methacrylic resin film (I), and the acrylic block copolymer. Utilizing the excellent transparency, flexibility and compatibility with various substrates of polymer film (II), for roofing materials such as corrugated plates, carports, arcades, balconies, wall materials, highway fences, and windows Building materials and housing equipment such as heat shield films; industrial and industrial uses such as sound insulation walls, nameplates, liquid crystal display covers, touch panels, display dummy cans, vehicle windows, pachinko machines, insulators, etc .; Fresnel lens for projection TV, lenticular lens, LCD (mobile phone, notebook computer, monitor, TV, etc.), PDP, front panel for projection TV, Transparent conductive film used in such touch panel, optical applications such as a lens sheet, the decorative plate can be used in a wide variety of articles display applications such as such as a mirror.

  The multilayer film of the present invention is suitably used as a decorative film with improved strength by taking advantage of excellent transparency and surface smoothness, high surface hardness and resistance to warm water whitening, good appearance (low blisters) and colorability. It is possible to impart strength and metallic luster to various substrates. For example, it is suitable for building materials such as vehicle interiors, furniture, door materials, and baseboards, and is particularly suitable for exterior and semi-exterior applications that require water resistance among the building materials. Specifically, it can be suitably used for window frames, entrance doors, shutters, and outer walls.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited at all by this Example.

(1) Number average molecular weight (Mn), weight average molecular weight (Mw), molecular weight distribution (Mw / Mn) by gel permeation chromatography (GPC), and measuring apparatus for the production rate of block copolymer (B): Tosoh Corporation Gel permeation 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) Apparatus for measuring polymerization conversion rate of charged monomer by gas chromatography (GC): 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) Side chain vinyl bond content The block copolymer (B) is dissolved in deuterated chloroform to obtain a test solution, and the test solution is prepared using ¹ H-NMR (JEOL Nuclear Magnetic Resonance Device (JNM-LA400)). The chemical shift of 4.7 to 5.2 ppm (hereinafter referred to as signal C ₀ ) 1,2-vinyl protons (= CH ₂ ) and chemical shift of 5.2 to 5.8 ppm (hereinafter referred to as signal). D ₀ that.) determine the integrated intensity of the vinyl protons (= CH-), and the following equation was determined by calculating the side chain vinyl bond content V ₀ [mol%].
V ₀ = _{[(C 0/2) / {} C 0/2 + (D 0 -C 0/2) / 2} ] × 100 (iv)

(4) Structure of block copolymer (B), composition ratio of each polymer block in acrylic block copolymer (C) Structure of block copolymer (B) and each polymer in acrylic polymer block The composition ratio of the block was determined by ¹ H-NMR ( ¹ H-nuclear magnetic resonance) measurement.
・ Device: JEOL Nuclear Magnetic Resonance Device “JNM-LA400”
・ Deuterated solvent: Deuterated chloroform

(5) Refractive index (n _d )
The block copolymer (B) was uniformly dissolved in toluene so as to be 30% by mass. The density of the solution and toluene and the refractive index with an Abbe refractometer were measured at room temperature, and the refractive index of the block copolymer (B) was determined using the following formulas (v) to (vii). Further, polymethyl methacrylate having a known refractive index (n _d = 1.492) is measured by the same method, a calibration coefficient for refractive index measurement by this method is obtained, and the refractive index of the block copolymer (B) is calibrated. did.
[(N _d ² −1) / (n _d ² +2)] × V = r = constant (v)
r ₃ = w ₁ r ₁ + w ₂ r ₂ (vi)
V ₂ = (1 / ρ ₁ ) − (1 / W ₂ ) × [(1 / ρ ₁ ) − (1 / ρ ₃ )] (vii)
[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,
_{Found: V 3, n d3, V} 1, nd 1]
Formula (v), Formula (vi) Source: Polymer Experimental Studies Vol. 12, “Thermodynamic, Electrical and Optical Properties”
Published in 1984 Kyoritsu Publishing Ceremony (vii) Source: Polymer Experiments Vol. 11, “Polymer Solution”, published in 1982 Kyoritsu Publishing

(5) Glass transition temperature (Tg)
The glass transition temperature of polyacrylic acid n- butyl used as the polymer block (a) (Tg _a), the "POLYMER HANDBOOK FOURTH Edition, VI / 199 pages, Wiley Interscience, New York, 1998" value according to (- 49 ° C.).
The glass transition temperature (Tg _b ) of the polybutadiene used as the polymer block (b) is the relationship between the amount of 1,2-vinyl bond and Tg described in “ANIONIC POLYMERIZATION, page 434, MARCEL DEKKER, Inc. 1996”. A more derived value was used.
The polymethyl methacrylate used as the polymer block (c) and the poly (n-butyl acrylate) used as the polymer block (d) were measured using a DSC measuring device (DSC-822) manufactured by METTLER. In the curve obtained by DSC measurement at a temperature increase rate of 10 ° C./min, the extrapolation start temperature (Tgi) was defined as the glass transition temperature (Tg).

(6) Evaluation of transparency of multilayer film The haze of a laminated film having a thickness of 1 mm was measured in accordance with ISO14782.

(7) Laminate formability The multilayer film obtained in the examples or comparative examples was visually observed to check for whitening at the interface between the flow mark and the first layer and the second layer. The case where none of the whitening occurred was evaluated as good (◯), and the case where the flow mark and / or the layer interface was whitened was evaluated as defective (×).

(8) Adhesion A methacrylic resin film (I), an acrylic block copolymer film (II), and a multilayer film obtained by laminating them are vacuum-deposited (SRC-10D, manufactured by Nippon Sink Technology Co., Ltd.). The aluminum film was deposited under a vacuum of 5 × 10 ⁻⁵ torr so that the deposited film had a thickness of 100 angstroms to obtain a multilayer film having a metal layer. The sample was subjected to a grid cut tape peeling test in accordance with JIS K5400. That is, with a cutter knife, a grid-like cut surface was attached to the deposited film at an interval of 1 mm to make 100 grids, and an adhesive tape (Cero tape (registered trademark), manufactured by Nichiban) was pasted and peeled off. The later results are shown in Table 2. The remaining number of 100 squares was counted, and 100/100 was the case without any separation, and 0/100 was the case where all the squares were peeled off together with the adhesive tape. For some samples, the adhesion state after the adhesion test when the metal layer was 800 angstroms was observed with an optical microscope.

  In the synthesis examples shown below, the compound was dried and purified by a conventional method and degassed with nitrogen. Moreover, the transfer and supply of the compounds were performed in a nitrogen atmosphere.

<< Synthesis Example 1 >> Production of Block Copolymer (B-1) (1) To a 1.5 liter autoclave equipped with a stirrer, 801 ml of toluene and 0.007 ml of 1,2-dimethoxyethane were charged and purged with nitrogen for 20 minutes. went. Thereto was added 1.9 ml of a cyclohexane solution containing 1.3 mol / l of sec-butyllithium, and then 97 ml of butadiene was added and reacted at 30 ° C. for 3 hours to obtain a reaction mixture containing a polybutadiene polymer. As a result of sampling analysis of a part of the obtained reaction mixture, the butadiene polymer in the reaction mixture has a number average molecular weight (Mn) of 48,700, a molecular weight distribution (Mw / Mn) of 1.06, and a side chain vinyl. The bonding amount was 30 mol%, and the glass transition temperature of polybutadiene (polymer block (b)) was −77 ° C.
(2) The reaction mixture obtained in the above (1) is cooled to −30 ° C. and contains 0.45 mol / l isobutylbis (2,6-di-t-butyl-4-methylphenoxy) aluminum. 18.1 ml of toluene solution and 8.1 ml of 1,2-dimethoxyethane were added and stirred for 10 minutes.
(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. As a result of sampling a part of the obtained reaction mixture and analyzing the molecular weight by GPC (polystyrene conversion), the polybutadiene-polyacrylate n-butyl diblock copolymer (arm polymer block) in the reaction mixture was number average. It was found that the molecular weight was 80,000 and the weight average molecular weight / number average molecular weight ratio (Mw / Mn) was 1.02. Moreover, the glass transition temperature of the polyacrylic acid n-butyl polymer block (a) was -49 degreeC.
(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 (a) composed of 49% by mass of a structural unit derived from butadiene and a polymer block (a) of 51% by mass composed of a structural unit derived from n-butyl acrylate. % Diblock copolymer as an arm polymer block. The refractive index of the block copolymer (B-1) was 1.492.

<< Synthesis Example 2 >> Production of Block Copolymer (B-2) Except that 1,2-dimethoxyethane was not used, the amount of butadiene was changed to 105 ml, and the amount of n-butyl acrylate was changed to 65 ml, In the same manner as in Synthesis Example 1, a block copolymer (B-2) was obtained. The obtained block copolymer (B-2) is mainly composed of a star block copolymer composed of 44% by mass of a structural unit derived from butadiene and 56% by mass of a structural unit derived from n-butyl acrylate. The polymer block (b) made of butadiene has a vinyl bond content of 10 mol%, a glass transition temperature of −95 ° C., and the polymer block (a) made of n-butyl acrylate is made of glass. The transition temperature was -49 ° C. The polybutadiene-polyacrylate n-butyl diblock copolymer (arm polymer block) has a number average molecular weight of 79,000, and the weight average molecular weight / number average molecular weight ratio (Mw / Mn) is 1.02. there were. The number average molecular weight (Mn) of the star block copolymer is 308,000 (number of arms = 3.88), 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 93% by mass. The refractive index of the block copolymer (B-2) was 1.492.

<< Synthesis Example 3 >> Synthesis of Acrylic Block Copolymer (C-1) After degassing the interior of a 2-liter three-necked flask and replacing with nitrogen, 1040 g of toluene and 100 g of 1,2-dimethoxyethane were added at room temperature, 48 g of a toluene solution containing 32 mmol of isobutylbis (2,6-di-t-butyl-4-methylphenoxy) aluminum was added, and 8.1 mmol of sec-butyllithium was further added. After 72 g of methyl methacrylate was added to this mixed solution and reacted at room temperature for 1 hour, 0.1 g of the reaction solution was collected (sampling sample 1). Subsequently, the internal temperature of the polymerization solution was cooled to −25 ° C., and 307 g of n-butyl acrylate was added dropwise over 2 hours. After completion of dropping, 0.1 g of the reaction solution was collected (sampling sample 2). Subsequently, 72 g of methyl methacrylate was added, and the reaction solution was returned to room temperature and stirred for 8 hours. The polymerization was stopped by adding 4 g of methanol to the reaction solution. The reaction solution after termination of the polymerization was poured into a large amount of methanol to obtain a deposited precipitate (sampling sample 3). ¹ H-NMR measurement and GPC measurement were performed using sampling samples 1 to 3, and based on the results, Mw (weight average molecular weight), Mw / Mn (molecular weight distribution), polymethyl methacrylate (PMMA) block and poly When the mass ratio of the n-butyl acrylate (PnBA) block was determined, the finally obtained precipitate was a PMMA-PnBA-PMMA triblock copolymer (PMMA-PnBA-PMMA), The MMMA of the PMMA block part is 9,900, Mw / Mn is 1.08, and the Mw of the entire triblock copolymer is 62,000, and Mw / Mn is 1.19. The ratio was PMMA (16 mass%)-PnBA (68 mass%)-PMMA (16 mass%). According to DSC measurement, the Tg of the PMMA block was 110 ° C., and the Tg of the PnBA block was −47 ° C.

<< Synthesis Example 4 >> Synthesis of Acrylic Block Copolymer (C-2) The same operation as in Synthesis Example 3 was performed to synthesize triblock copolymers (A2) having different molecular weights and copolymer composition ratios. Mw of the whole triblock copolymer obtained was 62,000, Mw / Mn was 1.11, and the proportion of PMMA block in the triblock copolymer was 50% by mass. Moreover, Tg of the PMMA block was 112 ° C., and Tg of the PnBA block was −47 ° C.

<< Reference Example 1 >> Production of Methacrylic Resin Composition (1) (1) Purified methyl methacrylate in an autoclave with a stirrer and sampling tube from which oxygen in the reaction system had been removed with nitrogen, 57.8 parts by mass, acrylic acid Then, 3.0 parts by mass of methyl and 35 parts by mass of toluene were added, and then 4.2 parts by mass of block copolymer (B-1) was added and stirred at 30 ° C. for 8 hours to obtain block copolymer (B-1). Was dissolved uniformly. 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.
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.
(2) In a piping part equipped with a static mixer manufactured by Noritake Engineering Co., Ltd., 0.001 mass of 1,1-di (t-butylperoxy) cyclohexane (“Perhexa C” manufactured by Nippon Oil & Fats Co., Ltd.) To the liquid discharged from the reactor A at a constant flow rate so as to become a part, and the liquid is added to a 5 L tank reactor B (theoretical complete mixing type reactor) controlled at 135 ° C. at a constant flow rate. Supplied. 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.
(3) Reactor so that t-butyl peroxybenzoate ("Perbutyl Z" manufactured by Nippon Oil & Fats Co., Ltd.) is 0.02 parts by mass with respect to the whole raw material liquid in a piping part equipped with a static mixer manufactured by Noritake Engineering Co., Ltd. B is added to the liquid discharged at a constant flow rate, and the liquid is constant in a tubular reactor C (theoretical plug flow reactor) equipped with a static mixer manufactured by Noritake Engineering Co., Ltd. whose inner wall temperature is controlled to 135 ° C. It was supplied at a 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.
(4) 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 Co., Ltd. whose inner wall temperature was controlled at 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.
(5) The liquid discharged from the tubular reactor D at a constant flow rate was heated to 230 ° C. and supplied to the 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.

Reference Example 2 Production of Methacrylic Resin Composition (2) Reference Example 1 except that the block copolymer (B-1) used in Reference Example 1 was changed to a block copolymer (B-2). A pellet-like methacrylic resin composition was obtained by the same method.

Reference Example 3 Production of Methacrylic Resin Films (I-1) to (I-2) T-die extrusion of the pellet-like methacrylic resin composition (I-1) with a lip width of 300 mm and a vertical gap of 0.3 mm A film having a thickness of 200 μm was continuously produced by melt-extrusion through a molding machine and drawing while stretching in the machine direction.

Reference Example 4 A methacrylic resin film (I-2) 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 obtain a film having a thickness of 100 μm. Manufactured continuously.

Reference Example 4 Production of Acrylic Block Copolymer Films (II-1) to (II-2) The acrylic block copolymers (C-1) and (C-2) and an acrylic resin to be described later Are mixed at a blending ratio shown in Table 1 below at 230 ° C. by a twin-screw extruder, and then extruded and cut to obtain acrylic block copolymers (C-1) and (C-2). A pellet of the containing composition was produced. The pellets were melt-extruded through a T-die extruder having a lip width of 300 mm and a vertical gap of 0.3 mm, and were drawn while being stretched in the longitudinal direction to continuously produce a film having a thickness of 125 μm. Table 1 shows the thickness and the like of the obtained film.

<< Reference Example 5 >>
The acrylic resin and metal used are shown below.
Acrylic resin (G): Parapet GF, manufactured by Kuraray Co., Ltd. Metal: Aluminum

[Examples 1 to 4 and Comparative Example 1]
The methacrylic resin films (I-1) to (I-2) obtained in the above reference example and the acrylic block copolymer films (II-1) to (II-2) are heat laminated with a roll width of 700 mm. Using an apparatus (VAII-700 type, manufactured by Taisei Laminator), lamination was performed under the conditions of 155 ° C., rotation speed 0.2 m / min, and roll pressure 0.6 MPa. Table 2 shows the results of transparency and laminate moldability of the obtained multilayer film.
Furthermore, a metal layer (aluminum layer) is formed on the acrylic block copolymer film (II) side of the obtained multilayer film by the method described in (8) above using a vacuum deposition apparatus, and the multilayer film is formed. Got. In Comparative Example 1, a metal layer was directly laminated on the methacrylic resin film (I). Table 2 shows the results of the adhesion of the metal layer of the obtained metal multilayer film. Moreover, the photograph of the adhesion state after adhesive evaluation in the case where the metal layer is 100 Å in the multilayer film of Example 1 and Comparative Example 1 is shown in FIGS.

[Example 5 and Comparative Example 2]
As Example 5 and Comparative Example 2, the same film as Example 1 and Comparative Example 1 was used, respectively, and a multilayer film having a metal layer was produced in the same manner except that the metal layer was 800 angstroms. FIG. 3 (Example 5) and FIG. 4 (Comparative Example 2) show the results of observation of the adhesion state after the adhesion evaluation with an optical microscope.

  From the results in Table 2, the laminated films of Examples 1 to 4 have excellent transparency and laminate moldability, and are excellent in adhesion to various metal layers. On the other hand, in Comparative Example 1 having no acrylic block copolymer film (II) layer, it can be seen that the adhesion to the metal layer is poor. Also, from FIGS. 1 and 3, those having the acrylic block copolymer film (II) as in Example 1 and Example 5 are completely the same regardless of whether the metal layer is 100 angstroms or 800 angstroms. There was no peeling and adhesion was good. On the other hand, as shown in FIG. 2, in the case of not having the acrylic block copolymer film (II) as in Comparative Example 1, when the metal layer is 100 angstroms, the metal layer on the almost entire surface where the adhesive tape is attached is It peeled. Further, from FIG. 4, in the case where the acrylic block copolymer film (II) was not used as in Comparative Example 2, even when the metal layer was 800 angstroms, part of the metal layer was peeled off.

The multilayer film of the present invention is used for roofing materials such as corrugated plates, carports, arcades, balconies, wall materials, highway fences, thermal insulation films for windows, etc .; sound insulation walls, nameplates, liquid crystal display covers Industrial and industrial applications such as touch panels, display dummy cans, vehicle windows, pachinko machines, insulators, etc .; light guide plates and diffusers for liquid crystal televisions, Fresnel lenses such as projection TVs, lenticular lenses, LCDs (mobile phones, laptop computers, It can be used for a wide range of articles such as optical applications such as monitors, TVs), PDP, projection TV front plates, transparent conductive films used for touch panels and the like, lens sheets; display applications such as decorative plates and mirrors.
Moreover, the multilayer film which laminated | stacked the metal layer of this invention can be used suitably as a strength improvement and a decorating film, and can provide intensity | strength and a metallic luster feeling to various base materials. For example, it is suitable for building materials such as vehicle interiors, furniture, door materials, and baseboards, and is particularly suitable for exterior and semi-exterior applications that require water resistance among the building materials. Specifically, it can be suitably used for window frames, entrance doors, shutters, and outer walls.

Claims (7)

The continuous phase (A) consisting of 100 parts by mass of a methacrylic resin having a structural unit derived from methyl methacrylate of 50% by mass or more has a glass transition temperature of 23 ° C. or less composed of a structural unit derived from an alkyl (meth) acrylate. 1 to 80 parts by mass of a block copolymer (B) having a polymer block (a) and a polymer block (b) having a glass transition temperature of 0 ° C. or lower composed of structural units derived from a conjugated diene compound A first layer comprising a methacrylic resin film (I) comprising a methacrylic resin composition present as a dispersed phase;
Two or more polymer blocks (c) having a glass transition temperature of 50 ° C. or higher composed of structural units derived from (meth) acrylic acid alkyl ester, and a glass transition temperature composed of structural units derived from (meth) acrylic acid alkyl ester A second layer comprising an acrylic block copolymer film (II) comprising a composition containing an acrylic block copolymer (C) having at least one polymer block (d) of 20 ° C. or lower; A multilayer film. 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 of formula (i):
[Number average molecular weight of star block copolymer]> 2 × [Number average molecular weight of arm polymer block] (i)
The multilayer film according to claim 1 satisfying The star block copolymer has the formula (ii):
(Polymer block (b) -polymer block (a)-) nX (ii)
(In the formula, X represents a coupling residue, and n represents a number exceeding 2.)
The multilayer film of Claim 2 represented by these.   The mass ratio of the polymer block (c) and the polymer block (d) in the acrylic block copolymer (C) is 20/80 to 80/20. Layer film. The acrylic block copolymer (C) has the formula (iii):
Polymer block (c) -polymer block (d) -polymer block (c) (iii)
The multilayer film in any one of Claims 1-4 represented by these.   The multilayer film according to claim 1, wherein a third layer made of metal is further laminated on the second layer. The multilayer film according to claim 6, wherein the third layer made of metal is a metal vapor deposition layer.