JP5031598B2 - Polycarbonate resin laminate - Google Patents

Description

The present invention relates to a polycarbonate resin laminate, more specifically, comprising a polycarbonate resin layer and a layer of a methacrylic resin composition, having high transparency, excellent surface smoothness, and surface hardness. Polycarbonate resin laminate that has an excellent balance between impact strength and impact resistance, and that does not whiten the methacrylic resin composition layer when stretched, folded, subjected to impact, and / or placed under long-term wet heat conditions About.
The present invention also includes a polycarbonate resin layer and a layer of a methacrylic resin composition containing an ultraviolet absorber, and relates to a polycarbonate resin laminate having excellent weather resistance in addition to the above features.

Polycarbonate resin has excellent transparency, impact resistance, and high heat distortion temperature, and is excellent in dimensional stability, processability and self-extinguishing properties, so it is used in many applications as window glass materials and optical materials. Yes. However, the polycarbonate resin has a problem that the surface hardness is inferior and is easily damaged, and the weather resistance is inferior, so that the impact strength is reduced and discoloration occurs in outdoor applications exposed to direct sunlight. Further, in order to increase the surface hardness of the polycarbonate resin, a hard coat treatment may be performed on the surface, but there is also a problem that the adhesion between the polycarbonate layer and the hard coat layer is not sufficient.
As a method of improving these problems, a method of coating a polycarbonate resin layer with a layer made of a (meth) acrylate polymer or copolymer is known.

For example, Patent Document 1 describes a polycarbonate sheet obtained by co-extrusion of polycarbonate and a (meth) acrylate polymer, and a polycarbonate sheet coated with a (meth) acrylate polymer layer. Patent Document 2 discloses an acrylic resin layer in which an ultraviolet absorbent having a glass transition temperature of 40 to 90 ° C. and a molecular weight of 400 or more is contained at 0.5 to 5.0 g / m ² on one or both sides of a polycarbonate resin sheet. A laminated body provided with is disclosed.
However, the polycarbonate resin laminate obtained as described above has a problem that the acrylic resin layer is easily broken when stretched, bent and / or subjected to an impact. For this reason, the polycarbonate resin laminate does not sufficiently satisfy the properties of high impact strength, bending strength and surface hardness and thinness which are required in applications such as a front plate of a mobile phone.
JP 55-59929 A JP-A-4-270652

Patent Document 3 discloses a two-phase mixing of a polymer (A) having a glass transition temperature of 10 ° C. or lower and a methyl methacrylate copolymer (B) having a glass transition temperature of 30 ° C. or higher on an aromatic polycarbonate layer. A multilayer plastic molding is described which is coated with a layer of polymer. As the polymer (A), a terpolymer composed of ethylene-propylene-diene and an acrylate elastic rubber based on butyl acrylate are disclosed. Moreover, the core-shell type particle | grains formed by coat | covering a polymer (A) centering on a copolymer (B) as a two-phase mixed polymer are disclosed.
The laminate obtained by the method of Patent Document 3 is less likely to crack in the two-phase mixed polymer layer even when stretched, bent and / or impacted, but is easily whitened and has transparency. There was a new problem of lowering. Moreover, when it laminated | stacked using a core-shell type particle | grain in a laminated body, there existed a problem that surface smoothness fell derived from particle | grains and transparency was inferior (hazing was high).
JP-A-2-175245

  It is an object of the present invention to have high transparency, excellent surface smoothness, excellent balance between surface hardness and impact resistance, and when stretched, bent, subjected to an impact, and / or for a long time. An object of the present invention is to provide a polycarbonate resin laminate in which a methacrylic resin composition layer does not whiten when placed under wet heat conditions.

  As a result of intensive investigations in order to achieve the above object, the present inventor conducted strong shearing of a specific methacrylic resin (A) and a specific polyvinyl acetal resin (B) on at least one surface of the polycarbonate resin layer. By providing a layer having a thickness of 5 to 200 μm made of a methacrylic resin composition obtained by melting and kneading, it has high transparency, excellent surface smoothness, and balance between surface hardness and impact resistance. It has been found that a polycarbonate resin laminate is obtained which is excellent and is not whitened when stretched, bent, subjected to impact and / or subjected to a long period of wet heat conditions. The present invention has been further studied and completed based on this finding.

That is, the present invention includes the following aspects.
(1) A polycarbonate resin laminate comprising a polycarbonate resin layer and a layer having a thickness of 5 to 200 μm comprising a methacrylic resin composition,
The methacrylic resin composition is
A methacrylic resin (A) having a weight average molecular weight (Mw) of 40000 or more;
A polyvinyl acetal resin (B) obtained by (co) acetalizing a polyvinyl alcohol resin having a number average polymerization degree of 200 to 4000 with an acetalization degree of 55 to 83 mol%,
With a mass ratio (A) / (B) of 99/1 to 51/49,
It is formed by melt-kneading under conditions of a shear rate of 100 sec ^-1 or more, and the methacrylic resin (A) forms a continuous phase.
Polycarbonate resin laminate.
(2) The polycarbonate resin laminate according to (1), wherein the methacrylic resin composition contains 0.1 to 2% by mass of an ultraviolet absorber.
(3) The polycarbonate resin laminate according to (1) or (2), wherein the roughness of the surface of the layer made of the methacrylic resin composition opposite to the surface in contact with the polycarbonate resin layer is 1.5 nm or less. body.
(4) The polycarbonate resin laminate according to any one of (1) to (3), wherein the haze measured according to JIS K7136 is 0.3% or less.
(5) The polycarbonate resin laminate according to any one of (1) to (4), which is a film, a sheet, or a plate.
(6) in a dynamic viscoelasticity measurement, the glass transition temperature Tg _AP due to methacrylic resin of a methacrylic resin composition (A) is a methacrylic resin (A) alone with a glass transition temperature (Tg _A) The polycarbonate resin laminate according to any one of (1) to (5), which shows a value between the glass transition temperature (Tg _B ) of the polyvinyl acetal resin (B) alone.

The polycarbonate resin laminate of the present invention has high transparency, excellent surface smoothness, excellent balance between surface hardness and impact resistance, and when stretched, folded, subjected to impact and / or Alternatively, the methacrylic resin composition layer does not whiten when placed under wet heat for a long time. Moreover, in addition to said feature, the laminated body which was excellent in the weather resistance can be obtained by containing the ultraviolet absorber in the layer of the methacrylic resin composition laminated | stacked on polycarbonate resin.
The polycarbonate resin laminate of the present invention is suitable for various glazing materials, optical members, LCD and EL display protective sheets, signboards, automobile window materials, soundproof walls, vending machine front plates, carports and the like. .

Hereinafter, the present invention will be described in detail.
The laminate of the present invention comprises a layer made of a polycarbonate resin and a layer made of a methacrylic resin composition.
The polycarbonate resin used for the polycarbonate resin layer constituting the present invention is not particularly limited. The polycarbonate resin is a polymer obtained by a reaction between a polyfunctional hydroxy compound and a carbonate ester-forming compound.

  Examples of the polyfunctional hydroxy compound include 4,4′-dihydroxybiphenyls which may have a substituent; bis (hydroxyphenyl) alkanes which may have a substituent; Good bis (4-hydroxyphenyl) ethers; optionally substituted bis (4-hydroxyphenyl) sulfides; optionally substituted bis (4-hydroxyphenyl) sulfoxides; substituted Bis (4-hydroxyphenyl) sulfones optionally having a group; bis (4-hydroxyphenyl) ketones optionally having a substituent; bis (hydroxyphenyl) optionally having a substituent ) Fluorenes; optionally substituted dihydroxy-p-terphenyls; optionally substituted dihydroxy-p-quarterpheny Bis (hydroxyphenyl) pyrazines optionally having a substituent; bis (hydroxyphenyl) menthanes optionally having a substituent; bis [2- (4-hydroxyphenyl) -2-propyl] benzenes; dihydroxynaphthalenes optionally having substituents; dihydroxybenzenes optionally having substituents; poly optionally having substituents Siloxanes; dihydroperfluoroalkanes which may have a substituent, and the like.

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

  Examples of the carbonate ester-forming compound include various dihalogenated carbonyls such as phosgene, haloformates such as chloroformate, and carbonate ester compounds such as bisaryl carbonate. The amount of the carbonate ester-forming compound may be appropriately adjusted in consideration of the stoichiometric ratio (equivalent) of the reaction.

  The reaction is usually performed in a solvent in the presence of an acid binder. Examples of acid binders include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, lithium hydroxide, and cesium hydroxide, alkali metal carbonates such as sodium carbonate and potassium carbonate, trimethylamine, triethylamine, tributylamine, Tertiary amines such as N, N-dimethylcyclohexylamine, pyridine, dimethylaniline, trimethylbenzylammonium chloride, triethylbenzylammonium chloride, tributylbenzylammonium chloride, trioctylmethylammonium chloride, tetrabutylammonium chloride, tetrabutylammonium bromide Quaternary ammonium salts, quaternary phosphonium salts such as tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, etc. And the like. Furthermore, if desired, a small amount of an antioxidant such as sodium sulfite or hydrosulfide may be added to this reaction system. The amount of the acid binder may be appropriately adjusted in consideration of the stoichiometric ratio (equivalent) of the reaction. Specifically, 1 equivalent or an excess amount, preferably 1 to 5 equivalents of acid binder may be used per 1 mol of hydroxyl group of the starting polyfunctional hydroxy compound.

  Moreover, a well-known terminal stopper and a branching agent can be used for reaction. As the terminator, p-tert-butyl-phenol, p-phenylphenol, p-cumylphenol, p-perfluorononylphenol, p- (perfluorononylphenyl) phenol, p- (perfluoroxylphenyl) phenol , P-tert-perfluorobutylphenol, 1- (P-hydroxybenzyl) perfluorodecane, p- [2- (1H, 1H-perfluorotridodecyloxy) -1,1,1,3,3,3- Hexafluoropropyl] phenol, 3,5-bis (perfluorohexyloxycarbonyl) phenol, perfluorododecyl p-hydroxybenzoate, p- (1H, 1H-perfluorooctyloxy) phenol, 2H, 2H, 9H-par Fluorononanoic acid, 1,1,1,3,3,3 Such Tetorafuroro 2-propanol.

  Examples of branching agents include phloroglysin, pyrogallol, 4,6-dimethyl-2,4,6-tris (4-hydroxyphenyl) -2-heptene, 2,6-dimethyl-2,4,6-tris (4- Hydroxyphenyl) -3-heptene, 2,4-dimethyl-2,4,6-tris (4-hydroxyphenyl) heptane, 1,3,5-tris (2-hydroxyphenyl) benzene, 1,3,5- Tris (4-hydroxyphenyl) benzene, 1,1,1-tris (4-hydroxyphenyl) ethane, tris (4-hydroxyphenyl) phenylmethane, 2,2-bis [4,4-bis (4-hydroxyphenyl) ) Cyclohexyl] propane, 2,4-bis [2-bis (4-hydroxyphenyl) -2-propyl] phenol, 2,6-bis (2-hydroxy-) -Methylbenzyl) -4-methylphenol, 2- (4-hydroxyphenyl) -2- (2,4-dihydroxyphenyl) propane, tetrakis (4-hydroxyphenyl) methane, tetrakis [4- (4-hydroxyphenylisopropyl) ) Phenoxy] methane, 2,4-dihydroxybenzoic acid, trimesic acid, cyanuric acid, 3,3-bis (3-methyl-4-hydroxyphenyl) -2-oxo-2,3-dihydroindole, 3,3- Bis (4-hydroxyaryl) oxindole, 5-chloroisatin, 5,7-dichloroisatin, 5-bromoisatin and the like can be mentioned.

The polycarbonate resin may contain a unit having a polyester, polyurethane, polyether or polysiloxane structure in addition to the polycarbonate unit.
The polycarbonate resin suitably used in the present invention is not particularly limited by its molecular weight, but has a viscosity average molecular weight of about 13,000 to 30,000 or a melt at 250 ° C. and 100 sec ⁻¹ from the viewpoint of ease of production by extrusion molding. A thing with a viscosity of about 13,000-60000 poise is preferable. The molecular weight can be adjusted by adjusting the amount of the terminal terminator or branching agent.
The polycarbonate resin used in the present invention has various additives as necessary, for example, an antioxidant, a stabilizer, an ultraviolet absorber, a lubricant, a processing aid, an antistatic agent, a colorant, an impact resistance aid, A foaming agent, a filler, a matting agent, etc. may be blended.
In addition, it is preferable that a softener and a plasticizer are not included in a large amount from the viewpoints of mechanical properties and surface hardness of the polycarbonate resin laminate of the present invention.

The shape of the polycarbonate resin layer is not particularly limited, but is preferably a thin, wide area such as a film, sheet or plate.
Although there is no restriction | limiting in particular in the thickness of a polycarbonate resin layer, Usually, 0.05-20 mm, Preferably it is 0.1-10 mm, More preferably, it is 0.2-10 mm.
The surface of the polycarbonate resin layer on the side in contact with the layer made of the methacrylic resin composition may be subjected to a surface treatment in order to improve adhesion. Examples of the surface treatment include corona discharge treatment and plasma treatment.

  The methacrylic resin composition used in the layer comprising the methacrylic resin composition constituting the present invention is obtained by melt-kneading a methacrylic resin (A) and a polyvinyl acetal resin (B).

  The methacrylic resin (A) used in the present invention is obtained by polymerizing a monomer mixture containing an alkyl methacrylate.

  As alkyl methacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, pentyl methacrylate, hexyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, myristyl Examples thereof include methacrylate, palmityl methacrylate, stearyl methacrylate, behenyl methacrylate, cyclohexyl methacrylate, and phenyl methacrylate. These alkyl methacrylates may be used alone or in combination of two or more. Of these, alkyl methacrylates having 1 to 4 carbon atoms in the alkyl group are preferred, and methyl methacrylate is particularly preferred.

Examples of monomers other than alkyl methacrylate include alkyl acrylate.
As alkyl acrylates, methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, n-butyl acrylate, sec-butyl acrylate, tert-butyl acrylate, pentyl acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, myristyl Examples include acrylate, palmityl acrylate, stearyl acrylate, behenyl acrylate, cyclohexyl acrylate, and phenyl acrylate. Of these, alkyl acrylates having 1 to 8 carbon atoms in the alkyl group are preferred. These alkyl acrylates may be used alone or in combination of two or more.

The methacrylic resin (A) may be one obtained by copolymerizing another ethylenically unsaturated monomer copolymerizable with alkyl methacrylate and alkyl acrylate.
Examples of the ethylenically unsaturated monomer copolymerizable with alkyl methacrylate and alkyl acrylate include diene compounds such as 1,3-butadiene and isoprene; styrene, α-methylstyrene, vinyltoluene, 2,4-dimethylstyrene, Styrene substituted with halogen, 1-vinylnaphthalene, 4-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, 4- (phenylbutyl) styrene, etc. Vinyl aromatic compounds; ethylenically unsaturated nitriles such as acrylonitrile and methacrylonitrile; acrylic acid, methacrylic acid, acrylamide, methacrylamide, maleic anhydride, maleic imide, monomethyl maleate, dimethyl maleate, etc. It is possible.
These ethylenically unsaturated monomers may be used alone or in combination of two or more.

In the methacrylic resin (A) used in the present invention, the proportion of the alkyl methacrylate unit is preferably 50 to 100% by mass, more preferably 80 to 99.9% by mass from the viewpoint of weather resistance. .
Moreover, it is preferable to contain an alkylacrylate unit in 0.1-20 mass% from a heat resistant viewpoint of methacrylic resin (A).

  The methacrylic resin (A) used in the present invention has a weight average molecular weight (denoted as Mw, the same shall apply hereinafter) of 40,000 or more, preferably 40,000 to 10,000, from the viewpoint of strength characteristics and meltability. 000, more preferably 80,000 to 1,000,000. The methacrylic resin (A) used in the present invention may be one in which monomers are linearly bonded, may have a branch, or may have a cyclic structure. good.

  The methacrylic resin (A) used in the present invention is not particularly limited as long as it is a method capable of polymerizing an α, β-unsaturated compound, but is preferably produced by radical polymerization. Examples of the polymerization method include bulk polymerization, suspension polymerization, solution polymerization, and emulsion polymerization.

  Examples of radical polymerization initiators used during polymerization include azo compounds such as azobisisobutyronitrile and azobisγ-dimethylvaleronitrile; benzoyl peroxide, cumyl peroxide, oxyneodecanoate, diisopropyl peroxydicarbonate, t Examples thereof include peroxides such as -butyl cumyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, cyclohexanone peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, and lauroyl peroxide. The polymerization initiator is usually used in an amount of 0.05 to 0.5 parts by mass with respect to 100 parts by mass of all monomers. The polymerization is usually performed at a temperature of 50 to 140 ° C. for 2 to 20 hours.

  In order to control the molecular weight of the methacrylic resin (A), a chain transfer agent can be used. Examples of chain transfer agents include methyl mercaptan, ethyl mercaptan, isopropyl mercaptan, n-butyl mercaptan, t-butyl mercaptan, n-hexyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, ethylthioglycoate, mercaptoethanol, thio- β-naphthol, thiophenol and the like can be mentioned. The chain transfer agent is usually used in the range of 0.005 to 0.5 mass% with respect to the total monomers.

  The methacrylic resin (A) used in the present invention contains various additives as necessary, for example, antioxidants, stabilizers, ultraviolet absorbers, lubricants, processing aids, antistatic agents, colorants, impact resistance. Auxiliaries, foaming agents, fillers, matting agents and the like may be blended. In addition, it is preferable that a softener and a plasticizer are not included abundantly from a viewpoint of the mechanical physical property and surface hardness of the laminated body obtained.

  The polyvinyl acetal resin (B) is usually a resin having a repeating unit represented by Chemical Formula 1.

In Chemical Formula 1, n is the number of aldehyde types used in the acetalization (natural number), R ₁ , R ₂ ,..., R _n is the alkyl residue or hydrogen atom of the aldehyde used in the acetalization reaction, _{k (1), k (2} ), ···, k (n) each of R _1, R _2, · · ·, the proportion of acetal units containing R _n (mol ratio), l is the vinyl alcohol unit The ratio (mol ratio), m is the ratio (mol ratio) of vinyl acetate units. However, k ₍₁₎ + k ₍₂₎ + ... + k _(n) + l + m = 1, and k ₍₁₎ , k ₍₂₎ , ..., k _(n) , l, and m are any May be zero. The repeating units are not particularly limited by the arrangement order shown in Chemical Formula 1, and may be arranged at random, may be arranged in a block shape, or may be arranged in a taper shape.

  The polyvinyl acetal resin (B) used in the present invention can be obtained, for example, by reacting a polyvinyl alcohol resin and an aldehyde.

  The polyvinyl alcohol resin used for the production of the polyvinyl acetal resin has a number average degree of polymerization of 200 to 4,000, preferably 300 to 3,000, more preferably 500 to 2,000. When the number average degree of polymerization of the polyvinyl alcohol resin is less than 200, the mechanical properties of the obtained polyvinyl acetal resin are insufficient, and the mechanical properties, particularly toughness, of the polycarbonate resin laminate of the present invention tends to be insufficient. On the other hand, when the number average degree of polymerization of the polyvinyl alcohol resin exceeds 4,000, the melt viscosity at the time of melt-kneading the methacrylic resin composition tends to increase.

A polyvinyl alcohol resin is not specifically limited by the manufacturing method, For example, what was manufactured by saponifying polyvinyl acetate etc. using an alkali, an acid, ammonia water, etc. can be used.
The polyvinyl alcohol resin may be completely saponified, or may be a partially saponified partially saponified polyvinyl alcohol resin. It is preferable to use a saponification degree of 80 mol% or more.

As the polyvinyl alcohol resin, a copolymer of vinyl alcohol and a monomer copolymerizable therewith, such as an ethylene-vinyl alcohol copolymer resin and a partially saponified ethylene-vinyl alcohol copolymer resin, can be used. . Furthermore, a modified polyvinyl alcohol resin into which carboxylic acid or the like is partially introduced can be used.
These polyvinyl alcohol resins may be used individually by 1 type, and may be used in combination of 2 or more types.

  The aldehyde used for production of the polyvinyl acetal resin (B) is not particularly limited. For example, formaldehyde (including paraformaldehyde), acetaldehyde (including paraacetaldehyde), propionaldehyde, butyraldehyde, n-octylaldehyde, amylaldehyde, hexylaldehyde, heptylaldehyde, 2-ethylhexylaldehyde, cyclohexylaldehyde, furfural, glyoxal, Examples include glutaraldehyde, benzaldehyde, 2-methylbenzaldehyde, 3-methylbenzaldehyde, 4-methylbenzaldehyde, p-hydroxybenzaldehyde, m-hydroxybenzaldehyde, phenylacetaldehyde, β-phenylpropionaldehyde and the like. These aldehydes may be used alone or in combination of two or more. Among these aldehydes, those mainly composed of butyraldehyde are preferable from the viewpoint of ease of production.

A polyvinyl acetal resin (B) obtained by acetalizing a polyvinyl alcohol resin with an aldehyde mainly composed of butyraldehyde is particularly referred to as polyvinyl butyral. In the present invention, polyvinyl butyral having a butyral unit ratio (see the following formula) of acetal units present in the polyvinyl acetal resin exceeding 0.9 is preferable. That is, in the structural formula of the polyvinyl acetal resin shown in Chemical Formula ₁ , when R ₁ = C ₃ H ₇ (alkyl residue of butyraldehyde), k ₍₁₎ / (k ₍₁₎ + k ₍₂₎ + -It is preferable that + k _(n) )> 0.9.

  The reaction between the polyvinyl alcohol resin and the aldehyde ((co) acetalization reaction) can be performed by a known method. For example, an aqueous solution method in which an aqueous solution of a polyvinyl alcohol resin and an aldehyde are acetalized in the presence of an acid catalyst to precipitate resin particles, the polyvinyl alcohol resin is dispersed in an organic solvent, and the aldehyde and the aldehyde are present in the presence of an acid catalyst. Examples thereof include a solvent method in which an acetalization reaction is performed and the reaction solution is precipitated with water or the like which is a poor solvent for the polyvinyl acetal resin. Of these methods, the aqueous medium method is preferable.

  The acid catalyst is not particularly limited. For example, organic acids such as acetic acid and p-toluenesulfonic acid; inorganic acids such as nitric acid, sulfuric acid and hydrochloric acid; gas which shows acidity when an aqueous solution such as carbon dioxide gas is used; cation exchange And solid acid catalysts such as metal oxides and metal oxides.

The degree of acetalization of the polyvinyl acetal resin (B) used in the present invention is 55 to 83 mol%, preferably 55 to 75 mol%. By adjusting the degree of acetalization within this range without acetalizing all the hydroxyl groups of the polyvinyl alcohol resin, the polycarbonate resin laminate of the present invention can be obtained easily and at low cost.
In addition, the acetalization degree (mol%) of polyvinyl acetal resin (B) can be defined by the following formula | equation.
Acetalization degree (mol%) =
{K ₍₁₎ + k ₍₂₎ + ... + k _(n) } × 2
/ {{K ₍₁₎ + k ₍₂₎ +... + K _(n) } × 2 + l + m} × 100

The degree of acetalization of the polyvinyl acetal resin is determined by titration of the mass proportion of vinyl alcohol units (l ₀ ) and the proportion of vinyl acetate units (m ₀ ) according to the method described in JIS K6728 (1977). The mass ratio (k ₀ ) of the unit is obtained by k ₀ = 1−l ₀ −m ₀ , and from this, the molar ratio (l) of the vinyl alcohol unit and the molar ratio (m) of the vinyl acetate unit are calculated, and k = 1− The ratio of vinyl acetal units (k = k ₍₁₎ + k ₍₂₎ +... + k _(n) ) is calculated by the formula of 1−m, and the degree of acetalization (mol%) = {k ₍₁₎ + k ₍₂₎ + ... + k _(n) } × 2 / {{k ₍₁₎ + k ₍₂₎ + ... + k _(n) } × 2 + l + m} × 100, or polyvinyl acetal resin Deuterated dimethylsulfur Was dissolved in Okisaido may be calculated by measuring the ¹ H-MMR or ¹³ C-NMR,.

The ratio of acetalization with butyraldehyde is particularly called the degree of butyralization. In the structural formula of polyvinyl acetal shown in Chemical Formula ₁ , when R ₁ = C ₃ H ₇ (an alkyl residue of butyraldehyde), the degree of butyralization is defined by the following formula.
Butyral degree (mol%) = {k ₍₁₎ } × 2
/ {{K ₍₁₎ + k ₍₂₎ +... + K _(n) } × 2 + l + m} × 100
The polyvinyl acetal resin used in the present invention preferably has a butyralization degree of 55 to 75 mol%, and more preferably 60 to 75 mol%. When a polyvinyl acetal resin having a butyralization degree in the above range is used, a polycarbonate resin laminate excellent in mechanical properties, particularly toughness, can be obtained easily and inexpensively. Further, when a polyvinyl acetal resin having a butyralization degree in the above range is used, the difference between the refractive index of the methacrylic resin (A) and the refractive index of the polyvinyl butyral is reduced, and the transparent characteristic of the methacrylic resin (A) is obtained. (High visible light transmittance, low haze) is easily maintained. Furthermore, when stretched, bent, subjected to an impact, and / or placed in a wet and heat condition for a long time, the feature of hardly whitening is likely to appear.

  Moreover, suitable polyvinyl acetal resin contains a vinyl alcohol unit normally 17-45 mol%, and contains a vinyl acetate unit normally 0 mol% or more and 5 mol% or less, Preferably it is 0 mol% or more and 3 mol% or less.

The slurry produced in the aqueous medium method and the solvent method is usually acidic due to an acid catalyst. As a method for removing the acid catalyst, the slurry is repeatedly washed with water, and the pH is usually adjusted to 5 to 9, preferably 6 to 9, more preferably 6 to 8; a neutralizing agent is added to the slurry, The method of adjusting pH to 5-9 normally, Preferably 6-9, More preferably, 6-8; The method of adding alkylene oxides etc. are mentioned.
Examples of the compound used for removing the acid catalyst include alkali metal compounds such as sodium hydroxide, potassium hydroxide, sodium acetate, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, ammonia, and an aqueous ammonia solution. Examples of alkylene oxides include ethylene oxide, propylene oxide; glycidyl ethers such as ethylene glycol diglycidyl ether.

Next, salts generated by neutralization, aldehyde reaction residues, and the like are removed. The removal method is not particularly limited, and methods such as repeated dehydration and water washing are usually used.
The water-containing polyvinyl acetal resin from which residues and the like have been removed is dried as necessary, processed into powder, granules, or pellets as necessary, and used as a molding material. When processing into a powder, granule, or pellet, it is preferable to reduce the aldehyde reaction residue, moisture, and the like by degassing under reduced pressure.

  The polyvinyl acetal resin used in the present invention includes various additives as necessary, for example, antioxidants, stabilizers, ultraviolet absorbers, lubricants, processing aids, antistatic agents, colorants, impact resistance aids, A foaming agent, a filler, a matting agent, etc. may be blended. In addition, it is preferable that a softener and a plasticizer are not included in a large amount from the viewpoints of mechanical properties and surface hardness of the polycarbonate resin laminate of the present invention.

  The methacrylic resin composition used in the present invention has a continuous phase formed of at least a methacrylic resin (A). When the methacrylic resin (A) forms a continuous phase, the heat resistance, surface hardness and rigidity of the laminate are improved.

In the methacrylic resin composition suitable for the present invention, at least two glass transition temperatures are observed in the dynamic viscoelasticity measurement. One is the glass transition temperature (Tg _AP ) due to the methacrylic resin (A) in the methacrylic resin composition, and the other is due to the polyvinyl acetal resin (B) in the methacrylic resin composition. Glass transition temperature (Tg _BP ).
When only one glass transition temperature of the methacrylic resin composition can be observed, that is, when Tg _AP = Tg _BP , the methacrylic resin (A) and the polyvinyl acetal resin (B) in the methacrylic resin composition Is in a completely compatible state.
When Tg _AP = Tg _A and Tg _BP = Tg _B , this indicates that the methacrylic resin (A) and the polyvinyl acetal resin (B) are in a completely incompatible state.

In contrast, the methacrylic resin composition of the preferred embodiment, the glass transition temperature Tg _AP due to methacrylic resin (A) of the methacrylic resin composition is a glass transition at methacrylic resin (A) alone It is a value between the temperature (Tg _A ) and the glass transition temperature (Tg _B ) of the polyvinyl acetal resin (B) alone. That is, the relationship of Tg _B <Tg _AP <Tg _A or Tg _A <Tg _AP <Tg _B is satisfied. Such methacrylic resin composition having a Tg _AP satisfying the relation is considered methacrylic resin (A) and the polyvinyl acetal resin (B) is partially turned compatible state.
In the present invention, when the methacrylic resin (A) is a combination of two or more methacrylic resins, the glass transition temperature of any one of the combinations is Tg _A , and the polyvinyl acetal resin (B) is In the case of a combination of two or more polyvinyl acetal resins, the glass transition temperature of any one of the combinations is defined as Tg _B , and the above relationship, that is, Tg _B <Tg _AP <Tg _A or Tg _A <Tg _AP It is preferable that the relationship <Tg _B is satisfied.

Although the detailed reason is not clear, when the methacrylic resin (A) and the polyvinyl acetal resin (B) are partially compatible, the methacrylic resin composition has heat resistance, surface hardness, and rigidity as compared with the methacrylic resin. It is almost the same, and it is difficult to whiten when stretched, bent, subjected to an impact, and / or placed under a wet and heat condition for a long time. In addition, it has excellent toughness and handleability.
On the other hand, when the methacrylic resin (A) and the polyvinyl acetal resin (B) are completely compatible, the surface hardness of the methacrylic resin composition tends to decrease. Further, when the methacrylic resin (A) and the polyvinyl acetal resin (B) are completely compatible and Tg _B <Tg _A , the heat resistance tends to decrease. When the methacrylic resin (A) and the polyvinyl acetal resin (B) are completely incompatible, the strength decreases or whitens.

In the methacrylic resin composition, the mass ratio (A) / (B) of the methacrylic resin (A) to the polyvinyl acetal resin (B) is 99/1 to 51/49, preferably 95/5 to 60. / 40, more preferably 90/10 to 60/40. With such a mass ratio, the toughness, surface hardness and rigidity of the methacrylic resin composition are improved.
When the ratio of (B) is less than 1% by mass, the effect of improving the mechanical properties such as toughness of the laminate of the present invention tends to decrease. On the other hand, when the proportion of (B) exceeds 49% by mass, the surface hardness and rigidity of the laminate of the present invention tend to be insufficient.

A methacrylic resin composition preferably used in the present invention has a strain rate of 1 mm / min. Using a test piece of length 80 mm × width 10 mm × thickness 4 mm in accordance with JIS K7171. In accordance with the flexural modulus at the time of the test and the JIS K7162, a strain rate of 1 mm / min. At least one of the tensile elastic moduli when tested in (1) is 2 GPa or more, preferably 2.5 GPa or more, more preferably 2.7 GPa or more.
In addition, a methacrylic resin composition preferably used in the present invention has a strain rate of 1 mm / min. Using a test piece of length 80 mm × width 10 mm × thickness 4 mm according to JIS K7171. It has a yield point of stress when it is subjected to a bending test. The yield point of stress is the stress limit where plastic deformation starts in a solid.

Methacrylic resin composition used in the present invention, the methacrylic resin (A) and the polyvinyl acetal resin (B), a shear rate of 100 sec ^-1 or more, preferably by melt-kneading by applying shear than 200 sec ^-1 It is obtained. By applying such high shearing and melt-kneading, the layer made of the methacrylic resin composition has the same heat resistance, surface hardness and rigidity as the methacrylic resin, and is stretched, bent, It becomes difficult to whiten when subjected to an impact and / or when it is left for a long time under humid and heat conditions.
A suitable method for preparing the methacrylic resin composition includes a step of applying shear at a shear rate of 100 sec ⁻¹ or more when melt-kneading the methacrylic resin (A) and the polyvinyl acetal resin (B), And a step of reducing the shear rate to 50 sec ⁻¹ or less at least twice. When melt kneading with the shear rate changed as described above, when the layer made of the methacrylic resin composition is stretched, folded, subjected to an impact, and / or when it has been subjected to humid heat conditions for a long time. It becomes difficult to whiten.

In the preparation of the methacrylic resin composition, the methacrylic resin (A) and the polyvinyl acetal resin (B) are mixed into a known kneader such as a single screw extruder, a twin screw extruder, a Banbury mixer, a brabender, an open roll, or a kneader. It is important to knead each component in a molten state using Among these kneaders, a large shearing force is obtained, the methacrylic resin (A) is easy to form a continuous phase, is excellent in productivity, and is applied with a shear rate of 100 sec ⁻¹ or more. A twin screw extruder is preferable because a process including at least twice each of the steps of 50 sec ⁻¹ or less can be easily produced.
The resin temperature at the time of melt kneading is preferably 140 ° C. or higher, more preferably 140 to 270 ° C., and particularly preferably 160 to 250 ° C.

  After melt-kneading, it is cooled to a temperature of 120 ° C. or lower. Cooling is preferably performed more rapidly than natural cooling by, for example, immersing the melted strand in a tank in which cold water is stored. By rapid cooling, the methacrylic resin (A) forms a continuous phase, and the methacrylic resin (A) and the polyvinyl acetal resin (B) are easily fixed in a partially compatible state. The size of is very small. The size of the dispersed phase is usually 1 μm or less, preferably 200 nm or less.

  In the methacrylic resin composition, various additives as required, such as antioxidants, stabilizers, lubricants, processing aids, antistatic agents, colorants, impact modifiers, foaming agents, fillers, A matting agent or the like may be added. In addition, it is preferable not to add a large amount of a softening agent or a plasticizer from the viewpoint of mechanical properties and surface hardness of the polycarbonate resin laminate of the present invention.

Furthermore, an ultraviolet absorber can be added to the methacrylic resin composition for the purpose of improving the weather resistance of the laminate of the present invention. Although the kind of ultraviolet absorber is not specifically limited, A benzotriazole type, a benzophenone type, or a triazine type is preferable. The addition amount of a ultraviolet absorber is 0.01-2 mass% normally with respect to a methacrylic-type resin composition, Preferably it is 0.1-2 mass%.
In addition, the said additive added to a methacrylic-type resin composition may be added when manufacturing a methacrylic-type resin composition, and may be added just before shaping | molding mentioned later.

  The laminate of the present invention is prepared by separately preparing a thin film composed of a methacrylic resin composition and a polycarbonate resin layer, a method of laminating continuously between heating rolls, a method of thermocompression bonding with a press, A method of laminating simultaneously with pressure air or vacuum forming, a method of laminating with an adhesive layer (wet lamination); a method of casting a melted polycarbonate resin using a thin film composed of a methacrylic resin composition as a base material A method of coextruding a polycarbonate resin and a methacrylic resin composition;

  Production of a thin film composed of a methacrylic resin composition can be performed by a known film forming method. For example, melt extrusion molding methods with high shearing force such as T-die method, calendar method, inflation method, melt casting method and the like can be mentioned. According to the melt extrusion method with high shearing force, it has excellent transparency, improved toughness, excellent handleability, excellent balance between toughness, surface hardness and rigidity, and when stretched, folded, It is possible to obtain a laminate that is less likely to be whitened when subjected to an impact and / or when placed under a wet and heat condition for a long time. Among the methods for obtaining a thin film composed of a methacrylic resin composition, from the viewpoint of obtaining a thin film with good surface smoothness, good specular gloss, and low haze, the molten kneaded material is melted from a T die. Preferably, the method includes a step of forming by extruding and bringing both surfaces into contact with a mirror roll surface or a mirror belt surface. The roll or belt used at this time is preferably made of metal. In the case where the both sides of the melt-kneaded product thus extruded are brought into contact with the mirror surface and molded, it is preferable to press and sandwich the both sides of the molded body with a mirror roll or a mirror belt. The pinching pressure by the mirror roll or mirror belt is preferably higher, and the linear pressure is preferably 10 N / mm or more, and more preferably 30 N / mm or more.

  From the viewpoint of obtaining a thin film (or layer) made of an acrylic resin composition having good surface smoothness, good mirror gloss, and low haze, at least one of a mirror roll and a mirror belt sandwiching the methacrylic resin composition is used. It is preferable that the surface temperature of both the mirror surface roll and the mirror surface belt sandwiching the molded body is 130 ° C. or less. When the surface temperature of both the mirror surface roll and the mirror surface belt is less than 60 ° C., the surface smoothness of the resulting thin film made of the acrylic resin composition tends to be insufficient and the haze tends to increase. Since the thin film and the mirror roll or mirror belt are in close contact with each other when the temperature exceeds ℃, the surface is easily roughened when the thin film made of the acrylic resin composition is peeled off from the mirror roll or mirror belt, and the resulting acrylic resin composition There is a tendency that the surface smoothness of the thin film consisting of becomes lower or the haze becomes higher.

  The resin temperature in the melt extrusion method is preferably 140 to 270 ° C, more preferably 160 to 250 ° C. After melt molding, it is preferable to cool the thin film more rapidly than natural cooling. For example, it is preferable that the thin film immediately after being formed is brought into contact with a cooling roll for rapid cooling. By performing such rapid cooling, a thin film in which the methacrylic resin (A) forms a continuous phase and the methacrylic resin (A) and the polyvinyl acetal resin (B) are partially compatible can be obtained. .

  The roughness of at least one surface of the thin film comprising the methacrylic resin composition used in the present invention, preferably the surface opposite the surface in contact with the polycarbonate resin layer, is preferably 1.5 nm or less, more preferably 0. .1 to 1.0 nm. 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. Moreover, in optical use, it is excellent in optical characteristics such as light transmittance and in shaping accuracy when performing surface shaping. In addition, the roughness of a film is the value calculated | required by the method as described in an Example.

  The haze of a thin film made of a methacrylic resin composition is preferably 0.3% or less, more preferably 0.2% 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 thin film which consists of a methacrylic-type resin composition is 5-200 micrometers, Preferably it is 50-200 micrometers, More preferably, it is 50-125 micrometers. When it is thicker than 200 μm, the laminate property, handling property, cutting property, etc. are deteriorated, it becomes difficult to use as a film, and the unit price per unit area increases, which is not preferable because it is economically disadvantageous.
The thin film made of the methacrylic resin composition 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. Printing is preferably performed on the side in contact with the polycarbonate resin layer in order to prevent discoloration of the printing layer.

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

  The thin film made of the methacrylic resin composition may be a single layer film made of the methacrylic resin composition, or may be a laminated film of the methacrylic resin composition and another resin.

  The thin film made of the methacrylic resin composition may be colored. As a coloring method, a method in which a pigment or dye is contained in a methacrylic resin composition of a methacrylic resin (A) and a polyvinyl acetal resin (B), and the resin composition itself before molding is colored; a methacrylic resin composition Although the dyeing | staining method etc. which immerse and dye the thin film which consists of a thing in the liquid which disperse | distributed dye are mentioned, It does not specifically limit.

The polycarbonate resin layer can be obtained by a known molding method such as an extrusion molding method or an injection molding method.
The thin film made of the methacrylic resin composition obtained as described above and the thermocompression bonding of the polycarbonate resin layer can be performed using a known means such as a hot press machine or a hot roll machine. The temperature during thermocompression bonding is usually 50 to 250 ° C.
In addition, a thin film made of a methacrylic resin composition is placed in a mold, and a molten polycarbonate resin is poured onto the thin film so that the thin film made of the methacrylic resin composition is laminated simultaneously with the molding of the polycarbonate resin layer. You can also

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

  In the laminate of the present invention, the number of layers composed of a methacrylic resin composition and the number of polycarbonate resin layers are not particularly limited, but the surface hardness, weather resistance, adhesion during hard coat treatment, and impact resistance of the laminate are not limited. Excellent surface smoothness and transparency (haze), and a layer made of a methacrylic resin composition is difficult to whiten when the laminate is stretched, bent and / or subjected to an impact. From the viewpoint of holding, a layer made of a methacrylic resin composition is preferably the outermost layer.

In the laminate of the present invention, another layer may be interposed between the layer made of the methacrylic resin composition and the polycarbonate resin layer, or outside the layer made of the methacrylic resin composition, that is, Another layer may be laminated on the opposite side of the surface in contact with the polycarbonate resin layer.
As another layer interposed between the layer which consists of a methacrylic-type resin composition, and a polycarbonate resin layer, the layer which consists of the thermoplastic resin which is excellent in the transparency which may be colored is mentioned, for example.

Moreover, as another layer provided in the outer side of the layer which consists of a methacrylic-type resin composition, the layer which consists of transparent resin from a viewpoint of improving the designability of a laminated body is preferable. The resin material used for the outermost layer is preferably one having high surface hardness and weather resistance from the viewpoint that the surface of the laminate is not easily scratched and the design property lasts long. For example, even if it contains an ultraviolet absorber A good methacrylic resin is preferable.
Moreover, you may provide hard coat layers, such as an ultraviolet-ray cured film, as another layer provided in the outer side of the layer which consists of a methacrylic resin composition.
In addition, in order to improve adhesiveness etc. with another layer, you may perform surface treatments, such as a plasma process, an electron beam process, a corona treatment, on the surface of the layer which consists of a methacrylic resin composition.

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

  The laminate of the present invention is excellent in surface hardness, weather resistance, impact resistance, surface smoothness, and transparency (haze), and receives an impact when the layer made of a methacrylic resin composition is stretched or folded. Building materials and houses such as corrugated sheets, carports, arcades, balconies, roofing materials, wall materials, highway fences, etc. Equipment use, sound insulation wall, nameplate, liquid crystal display cover, touch panel, display dummy can, vehicle window, pachinko machine, mobile phone full board, insulator and other industrial and industrial applications, LCD TV diffuser, Fresnel lens such as PTV, lenticular It can be used in a wide range of optical applications such as lenses, LCDs, PTVs, projection TV front plates, and lens sheets.

  Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In the examples, “part” represents “part by mass” unless otherwise specified, and “%” represents “% by mass” unless otherwise specified.

The physical properties of the laminate of the present invention and its raw materials were evaluated according to the following methods.
(1) Weight average molecular weight Using tetrahydrofuran as a solvent, Shodex (trademark) GPC SYSTEM11 manufactured by Showa Denko KK was connected to Shodex (trademark) KF-806L as a column for gel permeation chromatography, and Shodex (trademark) as a detector. It measured using the differential refractive index detector RI-101. The sample solution was prepared by accurately weighing 3 mg of the polymer, dissolving the polymer in 3 ml of tetrahydrofuran, and filtering with a membrane filter having an opening of 0.45 μm. The flow rate during measurement was 1.0 ml / min. The weight average molecular weight (Mw) was calculated as the molecular weight in terms of polymethyl methacrylate based on a calibration curve prepared with standard polymethyl methacrylate manufactured by Polymer Laboratories.

(2) Observation of elastic modulus, yield point elongation, elongation at break, toughness and whitening state in bending test The elastic modulus, yield point elongation and elongation at break in the bending test are in accordance with JIS K7171, manufactured by Shimadzu Corporation Using graph AG-5000B, a strain rate of 1 mm / min. Using a test piece of length 80 mm × width 10 mm × thickness 4 mm obtained by the injection molding method. Measured with
Toughness was evaluated by the energy required for the test piece to break.
The whitening state is carried out by visually observing the whitening state of the test piece at a bending strain of 20%. When the length of the whitened portion in the length direction of the test piece is 2 mm or more, x, 0.3 mm The above and less than 2 mm were evaluated as Δ, the less than 0.3 mm as ◯, and the one in which no whitening was observed was evaluated as ◎.

(3) Observation of elastic modulus, elongation at break, toughness and whitening state in tensile test The elastic modulus in the tensile test was obtained by injection molding using Autograph AG-5000B manufactured by Shimadzu Corporation according to JIS K7162. In addition, a strain rate of 1 mm / min. Measured with Observation of breaking elongation, toughness, and whitening state was performed according to JIS K7162, using an autograph AG-5000B manufactured by Shimadzu Corporation and using a 1A-type dumbbell-shaped test piece obtained by an injection molding method. min. It evaluated by measuring by. Toughness was evaluated by the energy required for the test piece to break.
The whitening state is performed by visually observing the whitening state of the test piece at a tensile strain of 10%, and the length of the whitened portion in the length direction of the test piece is 10 mm or more x 1 mm or more The case of less than 10 mm was evaluated as Δ, the case of less than 1 mm was evaluated as ◯, and the case where no whitening was observed was evaluated as ◎.

(4) Glass transition temperature (Tg)
The main dispersion peak temperature (Tg) of loss tangent (tan δ) is 60 mm long × width obtained by cutting a test piece obtained by injection molding using EXSTAR6000 DMS manufactured by SII Nano Technology Co., Ltd. In a bending mode (both-end beam measurement), a rectangular parallelepiped test piece having a thickness of 10 mm and a thickness of 4 mm is subjected to a sinusoidal vibration of 10 Hz, a heating rate of 3 ° C./min. It was measured by.

(5) Morphological observation with a transmission electron microscope After making an ultra-thin section from a test piece obtained by injection molding using an ultramicrotome (Richert ULTRACUT-S manufactured by RICA), four polyvinyl acetal parts of a methacrylic resin composition were obtained. Samples were prepared by electron staining with ruthenium oxide vapor. The morphology of the sample thus prepared was observed using a transmission electron microscope H-800NA manufactured by Hitachi, Ltd. In the observed morphology, the unstained portion (methacrylic resin (A)) formed a continuous phase, and the methacrylic resin (A) was discontinuous was evaluated as x.

(6) Visible light transmittance of film Visible light calculated according to JIS R3106 by measuring the transmittance at a wavelength of 380 nm to 780 nm of a 100 μm thick film using a spectrophotometer U-4100 manufactured by Hitachi High-Technologies Corporation. The transmittance was measured.

(7) Haze of film It measured with the film of thickness 100micrometer according to JISK7136.
(8) Surface hardness of film The pencil hardness of a film having a thickness of 100 μm was measured according to JIS K5400.
(9) Elastic modulus, elongation at break, and toughness in film tensile test A plastic JIS1A type dumbbell-shaped test film is punched from a film having a thickness of 100 μm so as to be stretched in the MD direction at the time of a tensile test. Using AG-5000B, the strain rate is 5 mm / min. The test was conducted to measure the elastic modulus, elongation at break, and toughness of the test film. Toughness was evaluated by the energy required for the test film to break.

(10) Tear strength of the film Using an autograph AG-5000B manufactured by Shimadzu Corporation, an angle-less test film without cut in accordance with JIS K6252 standard was punched out, and a tensile speed of 5 mm / min. The maximum tear strength (unit: N / mm) in terms of thickness when the angle type test film without incision was torn was evaluated. The measurement was performed with a film having a thickness of 100 μm.

(11) Observation of the whitening state of the film When a film having a thickness of 100 μm is folded 180 ° so as to be creased in the TD direction, according to a visual evaluation, the folded portion is not whitened at all, and one of the folded portions Evaluation was made with Δ for the part whitened, and × for the whole bent part whitened.

(12) Morphological observation of methacrylic resin composition layer in film or laminate by transmission electron microscope After producing ultra-thin section from film or laminate using ultramicrotome (RICA ULTRACUT-S), methacrylic resin The polyvinyl acetal portion of the composition layer was electronically stained with ruthenium tetroxide vapor to prepare a sample. The morphology of the sample thus prepared was observed using a transmission electron microscope H-800NA manufactured by Hitachi, Ltd. In the observed morphology, the unstained portion (methacrylic resin (A)) of the methacrylic resin composition layer formed a continuous phase, and the methacrylic resin (A) was discontinuous. As evaluated.

(13) Measurement of surface roughness of film and laminate The shape of the surface was measured in DFM mode using an atomic force microscope (SPI4000 probe station E-sweep environment control unit manufactured by SII Nanotechnology). SI-DF20 (back Al) manufactured by SII Nano Technology was used as the probe. (Before sample measurement, a reference sample with a pitch of 10 μm and a step of 100 nm is measured, and the measurement error of the X-axis and Y-axis of the apparatus is 5% or less for 10 μm, and the error of the Z-axis is 5% or less for 100 nm I confirmed it.)
The observation area of the sample was 2 μm × 2 μm, and the measurement frequency was 1.0 Hz. The number of scan lines was 512 on the X axis and 512 on the Y axis. The measurement was performed in an atmospheric environment at 25 ° C. ± 2 ° C. and humidity 30 ± 5%. The obtained measurement data was analyzed by data processing software attached to the apparatus, and the average surface roughness Ra was obtained. In other words, after selecting the [Third-order tilt correction] command in the [Tool] menu of the measurement software of the apparatus and correcting the entire tilt of the film and large waviness, the [Surface roughness analysis] command in the [Analysis] menu is selected. The average surface roughness Ra was selected. The average surface roughness Ra is defined as follows.
* Average surface roughness Ra: A value obtained by averaging the absolute values of deviations from the reference surface to the specified surface.

ここでＦ（Ｘ，Ｙ）は（Ｘ，Ｙ）座標での高さの値を表す。Ｚ₀は以下で定義されるＺデータの平均値を表す。

Here, F (X, Y) represents a height value in the (X, Y) coordinates. Z ₀ represents the average value of Z data defined below.

また、Ｓ₀は、測定領域の面積を表す。
この平均面粗さＲａをフィルムの両面（便宜上、Ａ面およびＢ面とする）において異なる１０箇所の領域でそれぞれ測定し、１０箇所の平均面粗さＲａの平均値を成形体表面の粗度とした。また、積層体のアクリル系樹脂層において異なる１０箇所の領域で測定し、１０箇所の平均面粗さＲａの平均値を積層体表面の粗度とした。
３次傾き補正は、測定した試料表面を３次の曲面で最小２乗近似によってフィッティングすることによって行い、試料の傾きおよびうねりの影響を排除するために行った。

S ₀ represents the area of the measurement region.
The average surface roughness Ra was measured at 10 different regions on both surfaces of the film (for convenience, the A surface and the B surface), and the average value of the 10 average surface roughness Ra was determined as the roughness of the surface of the molded body. It was. Moreover, it measured in 10 area | regions different in the acrylic resin layer of a laminated body, and made the average value of 10 average surface roughness Ra the roughness of the laminated body surface.
The cubic inclination correction was performed by fitting the measured sample surface with a cubic surface by least square approximation to eliminate the influence of the inclination and waviness of the sample.

(14) Haze of laminate The haze of the laminate was measured according to JIS K7136.
(15) Elastic modulus, breaking elongation, and toughness in tensile test of laminate The plastic JIS1A type dumbbell shape test film was punched from the laminate so as to be stretched in the MD direction during the tensile test, and Autograph AG- manufactured by Shimadzu Corporation. Using 5000B, the strain rate is 5 mm / min. The test was conducted to measure the elastic modulus, elongation at break, and toughness of the test film. Toughness was evaluated by the energy required for the test film to break.

(16) Impact resistance of the laminate The laminate is horizontally fixed with a stainless steel jig having a circular hole with a diameter of 6.8 cm so that the laminate does not sag. The methacrylic resin of the laminate is obtained by changing the height from the laminate in increments of 10 cm with a 1 inch diameter stainless steel sphere (mass 67 g) under the condition that no other than this stainless steel jig is in contact. It was dropped from the composition surface side, and the impact resistance of the laminate was evaluated at the maximum height (cm) at which the layer made of the methacrylic resin composition was not broken.

(17) Surface hardness of laminate The pencil hardness was measured according to JIS K5400.
(18) Observation of the whitened state of the laminate When a strip of 6 cm in the MD direction and 1 cm in the TD direction is cut out from the laminate and folded at 90 ° so that a crease is formed in the TD direction, the bent portion is visually evaluated. Evaluation was made with ◯ indicating that the material was not whitened at all, Δ when the part of the folded portion was whitened, and Δ when the material was broken when folded. At that time, when the layer made of the methacrylic resin composition of the laminate is laminated only on one side, it is folded in a mountain fold with respect to the surface of the laminate made of the layer made of the methacrylic resin composition. And evaluated.

(19) Weather resistance of laminated body Accelerated exposure test was conducted using Atlas Xenon Weatherometer (Ci4000) in accordance with JIS B7754 (black panel temperature 63 ° C, humidity 50%, 120 minutes cycle 18 minutes spray). The test piece after 2000 hours exposure was visually observed to evaluate the weather resistance. In addition, the accelerated exposure test was performed so that only the methacrylic resin composition layer side of the laminate was irradiated with ultraviolet rays. By visual evaluation, the laminated body after the test was evaluated as “◯” when the crack was not present, and “X” when the crack was present.

[Methacrylic resin (A)]
A methacrylic resin composed of methyl methacrylate units and methyl acrylate units in the ratios shown in Table 1 was prepared by bulk polymerization. Table 1 shows the weight average molecular weight (Mw) and glass transition temperature (Tg) of the prepared methacrylic resin.

[Polyvinyl acetal resin (B)]
An aldehyde compound and an acid catalyst (hydrochloric acid) were added to an aqueous solution in which the polyvinyl alcohol resin was dissolved, and the mixture was stirred to acetalize to precipitate the resin. Wash until pH = 6 according to known methods, then suspend in alkaline aqueous medium and stir, wash again until pH = 7 and dry until volatile content is 1.0% Thus, polyvinyl acetal resins having the characteristics shown in Table 2 were obtained.

The degree of acetalization of the polyvinyl acetal resin was determined by the following procedure.
First, in accordance with the method described in JIS K6728 (1977), the mass ratio (l ₀ ) of the vinyl alcohol unit and the mass ratio (m ₀ ) of the vinyl acetate unit were determined by the methods described below. The mass ratio (k ₀ ) was determined by k ₀ = 1−l ₀ −m ₀ .
_{Then, l = (l 0 /44.1)/(l 0} /44.1+m 0 /86.1+2k 0 / Mw (acetal) and _{m = (m 0 /86.1)/(l 0/} 44. 1 + m ₀ /86.1+2k ₀ / Mw (acetal) is obtained by calculation, and the ratio of vinyl acetal units (k = k ₍₁₎ + k ₍₂₎ +... + K _{( n)} ), and finally, the degree of acetalization (mol%) = {k ₍₁₎ + k ₍₂₎ +... + k _(n) } × 2 / {{k ₍₁₎ + k ₍₂₎ + ... + k _(n) } × 2 + l + m} × 100.
Here, Mw (acetal) is the molecular weight per acetalization unit. For example, in the case of polyvinyl butyral, Mw (acetal) = Mw (butyral) = 142.2.
In the case of coacetalization with butyraldehyde and other aldehydes, ¹ H-NMR or ¹³ C-NMR can be measured, and the degree of acetalization (mol%) can be calculated.

[How to find l ₀ and m ₀ ]
About 0.4 g of polyvinyl acetal resin is accurately weighed into a conical Erlenmeyer flask, dissolved by adding 10 ml of a mixed solution of pyridine / acetic anhydride (volume ratio 92/8) with a pipette, and attached with a cooler at a temperature of 50 ° C. On a water bath for 120 minutes. After cooling, 20 ml of dichloroethane was added and shaken well. Further, 50 ml of water was added, stoppered and shaken vigorously, and allowed to stand for 30 minutes. The acetic acid produced is titrated with N / 2 sodium hydroxide solution with phenolphthalein as an indicator until it turns pale red, and the titration is defined as a (ml). Separately, a blank test was performed, and the titration amount of the N / 2 sodium hydroxide solution required for this was defined as b (ml), and obtained by the following formula.
l ₀ = 2.2 × (ba) × F _l / (s _l × P _l )
In the formula, s _{1 is} the mass of the polyvinyl acetal resin, P ₁ is the pure content (%), and F ₁ is the titer of the N / 2 sodium hydroxide solution.
Also, weigh accurately about 0.4 g of polyvinyl acetal resin in a conical flask with a stirrup, add 25 ml of ethanol and dissolve at 85 ° C., add 5 ml of N / 10 sodium hydroxide solution while shaking well with a pipette, and cool. The vessel was attached and refluxed in a water bath at a temperature of 85 ° C. for 60 minutes. After cooling, 5 ml of N / 10 hydrochloric acid was added with a pipette, shaken well, and allowed to stand for 30 minutes. Excess hydrochloric acid was titrated with a N / 10 sodium hydroxide solution using phenolphthalein as an indicator until a slight red color was obtained, and the titer was c (ml). Separately, a blank test was carried out, and the titration amount of the N / 10 sodium hydroxide solution required for this was determined as d (ml), and obtained by the following formula.
m ₀ = 0.86 × (cd) × F _m / (s _m × P _m )
In the formula, s _{m is} the mass of the polyvinyl acetal resin, P _m is the pure content (%), and F _m is the titer of the N / 10 sodium hydroxide solution.

Example 1
A cylinder temperature of 220 ° C. using 75 parts of methacrylic resin (A-1) and 25 parts of polyvinyl acetal resin (B-1) using a twin screw kneading extruder TEX-44α (L / D = 40) manufactured by Nippon Steel. The mixture was kneaded at a screw speed of 200 rpm to obtain a methacrylic resin composition pellet. The resin temperature measured immediately before the die of the extruder at that time was 230 ° C. Maximum shear rate of the extruder is 300 sec ^-1, shear rates in the clearance large portion of the barrel and the screw elements were 45 sec ^-1. Screw, the rotational speed of the used was a structure in which the shear shear and 45 sec ^-1 of 300 sec ^-1 is applied twice alternately.

The pellets of the obtained methacrylic resin composition were injection-molded at a cylinder temperature of 240 ° C. using J50E2 manufactured by Nippon Steel, and a plastic JIS 1A type dumbbell-shaped test piece having a length of 80 mm × width of 10 mm × thickness of 4 mm. A rectangular parallelepiped specimen was obtained. Furthermore, the rectangular parallelepiped test piece of length 60mm * width 10mm * thickness 4mm was obtained by cut | disconnecting the rectangular parallelepiped test piece of length 80mm * width 10mm * thickness 4mm.
Using these specimens, elastic modulus, yield elongation, elongation at break, toughness and whitening state in bending test; elastic modulus, elongation at break, toughness and whitening state in tensile test; methacrylic resin composition The glass transition temperature (Tg _AP ) attributed to the resin (A) was measured. In addition, the morphology was observed. Table 3 shows the results.
Moreover, the pellet of the obtained methacrylic-type resin composition was extrusion-molded on conditions with a cylinder temperature and T-die temperature of 220 degreeC from T-die of width 500mm using GT-40 by Plastics Engineering Laboratory, and just under T-die. A film having a thickness of 100 μm was obtained by sandwiching with two metal mirror rolls whose temperature was adjusted to 90 ° C. at a pressing pressure of 50 N / mm. Table 4 shows the visible light transmittance, haze, surface hardness, whitening state, surface roughness (denoted as A surface and B surface for the sake of convenience. The same applies hereinafter) of this film.
A film made of the methacrylic resin composition having a thickness of 100 μm and a polycarbonate film having a thickness of 500 μm (Iupilon film FE-2000, manufactured by Mitsubishi Engineering Plastics Co., Ltd.) are superposed one by one, and two surface temperatures of 170 ° C. The laminate was obtained by thermocompression bonding from both sides of the film by passing between the metal mirror rolls, and a methacrylic resin composition was laminated on one side of the polycarbonate film.
Table 5 shows the haze, morphology, elastic modulus, elongation at break and toughness of the obtained laminate, impact resistance, surface hardness, whitening state, surface roughness, and weather resistance.

Examples 2-4
A laminate was produced in the same manner as in Example 1 except that the types and / or blending amounts of the methacrylic resin (A) and the polyvinyl acetal resin (B) were changed to the formulations shown in Table 3. Their characteristics are shown in Tables 3 to 5.
The maximum shear rate of the extruder in Example 2 was 300 sec ⁻¹ , and the resin temperature measured immediately before the die of the methacrylic resin composition extruder was 225 ° C.
The maximum shear rate of the extruder in Example 3 was 300 sec ⁻¹ , and the resin temperature measured immediately before the die of the extruder for the methacrylic resin composition was 240 ° C.
The maximum shear rate of the extruder in Example 4 was 300 sec ⁻¹ , and the resin temperature measured immediately before the die of the methacrylic resin composition extruder was 231 ° C.

Example 5
The methacrylic resin composition pellets obtained in Example 1 were extruded from a T-die having a width of 500 mm and a cylinder temperature and a T-die temperature of 220 ° C. using GT-40 manufactured by Plastics Engineering Laboratory. A film made of a methacrylic resin composition having a thickness of 50 μm was obtained by sandwiching it with two metal mirror rolls adjusted to 90 ° C. at a pressing pressure of 50 N / mm.
A film made of a methacrylic resin composition having a thickness of 50 μm and a polycarbonate film having a thickness of 500 μm (Iupilon film FE-2000, manufactured by Mitsubishi Engineering Plastics Co., Ltd.) are converted into a film in which the polycarbonate film is made of a methacrylic resin composition. A laminate in which a methacrylic resin composition is laminated on both sides of a polycarbonate film by being superposed so as to be sandwiched from both sides and passing between two metal mirror rolls having a surface temperature of 170 ° C. Got. Properties such as mechanical properties are shown in Tables 3 to 5.

Example 6
The methacrylic resin composition pellets obtained in Example 1 were extruded from a T-die having a width of 500 mm and a cylinder temperature and a T-die temperature of 220 ° C. using GT-40 manufactured by Plastics Engineering Laboratory. A film made of a methacrylic resin composition having a thickness of 50 μm was obtained by sandwiching it with two metal mirror rolls adjusted to 90 ° C. at a pressing pressure of 50 N / mm.
A laminate was obtained in the same manner as in Example 1 except that this film was used. Tables 3 to 5 show mechanical properties.

Example 7
The methacrylic resin composition pellets obtained in Example 1 were extruded from a T-die having a width of 500 mm and a cylinder temperature and a T-die temperature of 220 ° C. using GT-40 manufactured by Plastics Engineering Laboratory. A film made of a methacrylic resin composition having a thickness of 20 μm was obtained by sandwiching it with two metal mirror rolls adjusted to 90 ° C. at a pressing pressure of 50 N / mm. A laminate was obtained in the same manner as in Example 1 except that this film was used. The results of measuring mechanical properties and the like are shown in Tables 3 to 5.

Example 8
A laminate was produced in the same manner as in Example 1 except that the type of the polyvinyl acetal resin (B) was changed to the formulation shown in Table 3. The results are shown in Tables 3-5.

Example 9
As a UV absorber, 75 parts of methacrylic resin (A-1), 25 parts of polyvinyl acetal resin (B-1), and a total of methacrylic resin (A-1) and polyvinyl acetal resin (B-1) are 0. A laminate was produced in the same manner as in Example 1 except that 8% by mass of Adekastab LA-31 was further added. The results are shown in Tables 3-5. Moreover, when the weather resistance of the laminated body was evaluated, the laminated body was not cracked and evaluated as ◯.

Example 10
A film made of the methacrylic resin composition having a thickness of 100 μm obtained in Example 1 and a polycarbonate sheet having a thickness of 2 mm (Iupilon sheet NF-2000; manufactured by Mitsubishi Engineering Plastics Co., Ltd.) are superposed one by one. A laminated body in which a methacrylic resin composition was laminated on one side of a polycarbonate film was thermocompression bonded from both sides of the film by passing between metal mirror rolls having a surface temperature of 170 ° C. The evaluation results are shown in Tables 3 to 5.

Comparative Example 1
Table 6 shows the results of measuring the mechanical properties of a polycarbonate single layer film (Iupilon film FE-2000; manufactured by Mitsubishi Engineering Plastics Co., Ltd.) having a thickness of 500 μm. Moreover, when the weather resistance of this single layer film was evaluated, the film was cracked and evaluated as x.

Comparative Example 2
A laminate was produced in the same manner as in Example 1 except that instead of the methacrylic resin composition pellets used in Example 1, pellets consisting only of the methacrylic resin (A-1) were used. The results are shown in Table 6.

Comparative Example 3
A laminate was produced in the same manner as in Example 1 except that instead of the methacrylic resin composition pellets used in Example 1, pellets consisting only of methacrylic resin (A-3) were used. The results are shown in Table 6.

Comparative Example 4
Instead of the methacrylic resin composition used in Example 1, it is a combination of a soft polymer layer containing alkyl acrylate units and a hard polymer layer containing alkyl methacrylate units, and the outermost layer is a hard polymer. The same as Example 1 except that the core-shell type particle-containing methacrylic resin composition consisting of 16 parts by mass of the multilayer structure polymer (C-1) as a layer and 84 parts by mass of the methacrylic resin (A-1) was used. Thus, a laminate was produced. The results are shown in Table 6.

Comparative Example 5
Instead of the methacrylic resin composition used in Example 1, it is a combination of a soft polymer layer containing alkyl acrylate units and a hard polymer layer containing alkyl methacrylate units, and the outermost layer is a hard polymer. Example 1 except that the core-shell type particle-containing methacrylic resin composition consisting of 28 parts by mass of the multilayer structure polymer (C-1) and 72 parts by mass of the methacrylic resin (A-1) is used. Thus, a laminate was produced. The results are shown in Table 6.

Comparative Example 6
The methacrylic resin composition pellets obtained in Example 1 were extruded from a T-die having a width of 500 mm and a cylinder temperature and a T-die temperature of 220 ° C. using GT-40 manufactured by Plastics Engineering Laboratory. A film made of a methacrylic resin composition having a thickness of 300 μm was obtained by sandwiching with two metal mirror rolls whose temperature was adjusted to 90 ° C. immediately below at a pressing pressure of 50 N / mm. A laminate was obtained in the same manner as in Example 1 except that this film was used. Table 6 shows the results of measuring the mechanical properties and the like of the obtained laminate.

As is clear from Tables 5 and 6, the laminate of the present invention has high transparency, excellent surface smoothness, excellent balance between surface hardness and impact resistance, and is bent when stretched. The methacrylic resin composition layer does not whiten when subjected to impact, and / or when subjected to wet heat for a long time.
Further, the laminate of the present invention has the same transparency, surface smoothness, and surface hardness as compared with the laminates of Comparative Example 2 and Comparative Example 3 having a layer made of only a methacrylic resin, and impact resistance. In addition, the methacrylic resin composition layer is not whitened when stretched, bent, subjected to an impact, and / or placed under a wet heat condition for a long time.
Furthermore, the laminate of the present invention has transparency and surface smoothness as compared with the laminates of Comparative Example 4 and Comparative Example 5 having a layer made of a methacrylic resin composition containing core-shell type particles. It is excellent, and the methacrylic resin composition layer does not whiten when stretched, bent, subjected to an impact, and / or placed under a wet and heat condition for a long time. On the other hand, in the laminates of Comparative Examples 4 and 5, the methacrylic resin composition layer is whitened when stretched, bent, subjected to impact, and / or placed under long-time wet heat conditions.

Claims (6)

A polycarbonate resin laminate comprising a polycarbonate resin layer and a layer having a thickness of 5 to 200 μm comprising a methacrylic resin composition,
The methacrylic resin composition is
A methacrylic resin (A) having a weight average molecular weight (Mw) of 40,000 or more containing 50 to 100% by weight of a methyl methacrylate unit ;
A polyvinyl acetal resin (B) obtained by (co) acetalizing a polyvinyl alcohol resin having a number average polymerization degree of 200 to 4000 with an acetalization degree of 55 to 83 mol%,
With a mass ratio (A) / (B) of 99/1 to 51/49,
It is formed by melt-kneading under a shear rate of 100 sec ⁻¹ or more, and the methacrylic resin (A) forms a continuous phase.
Polycarbonate resin laminate.
  The polycarbonate resin laminate according to claim 1, wherein the methacrylic resin composition contains 0.1 to 2% by mass of an ultraviolet absorber.   3. The polycarbonate resin laminate according to claim 1, wherein the surface of the layer made of the methacrylic resin composition on the side opposite to the surface in contact with the polycarbonate resin layer has a roughness of 1.5 nm or less.   The haze measured according to JIS K7136 is 0.3% or less, The polycarbonate resin laminated body of any one of Claims 1-3.   It is a film, a sheet | seat, or a board, The polycarbonate resin laminated body of any one of Claims 1-4. In the dynamic viscoelasticity measurement, the glass transition temperature Tg _AP due to methacrylic resin of a methacrylic resin composition (A) is methacrylic resin (A) alone with a glass transition temperature (Tg _A) and the polyvinyl acetal resin (B) alone indicates a value between the glass transition temperature (Tg _B) of the polycarbonate resin laminate according to any one of claims 1 to 5.