JP2017203148A - (meth)acrylic resin molding material, (meth)acrylic polymer and method for producing them, and method for producing molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a (meth)acrylic polymer acrylic molding material which is obtained from a monomer mixture containing a macromonomer and an acrylic ester monomer, and is excellent in transparency and heat resistance.SOLUTION: A (meth)acrylic resin molding material formed from a polymer containing an acrylic macromonomer (a) as a monomer unit is produced by a suspension polymerization method controlled on a polymerization temperature condition so that a polymerization start temperature and a 10 hr half-time temperature of a polymerization initiator satisfy a specific relational expression, and satisfies expression (1): 115+K×(1000/3)≤Tc. Tc represents a variation point temperature [°C]K of the (meth)acrylic resin molding material. K represents inclination of a straight line at 50-80°C in formula (2):ln(E')=KT+Cobtained by logarithmically plotting a storage elastic modulus E' [Pa] of the (meth)acrylic resin molding material to a temperature T[°C].SELECTED DRAWING: None

Description

  The present invention relates to a (meth) acrylic resin-based molding material, a (meth) acrylic polymer, a method for producing them, and a method for producing a molded body.

  Synthetic studies on monomers and polymers for various molding materials have been conducted, and various polymers are widely used as materials. Various properties such as mechanical properties, optical properties, and chemical properties of the polymer differ depending on the type of polymer. When these polymers are used industrially, homopolymers using one type of monomer cannot meet the various requirements of materials. Is used. However, when a random copolymer is used, the characteristics of each copolymerized monomer unit tend to be averaged.

Further, when two or more kinds of polymers are simply mixed, the polymers are separated without being mixed (called macrophase separation), and often inferior to the characteristics of each monomer unit.
In order to solve the above problems, block copolymers in which two or more polymer segments are chemically bonded are known. Since the polymers are difficult to mix with each other, phase separation occurs. However, since the polymers are connected to each other by a chemical bond, the phase separation structure becomes a nanometer size (called microphase separation). Therefore, the characteristics of each polymer segment can be exhibited without impairing the characteristics of each polymer segment.

On the other hand, among block copolymers, (meth) acrylic block copolymers have been tried to be applied in various applications that require transparency and light resistance.
As a method of obtaining a polymer having good transparency and light resistance and a molded article having good transparency and light resistance obtained from the polymer, a monomer mixture containing a macromonomer and a monomer having a polarity different from that of the macromonomer is used. A suspension polymerization method is known (Patent Document 1).
However, it has been found that the polymer obtained by the method of Patent Document 1 and the molded product obtained from the polymer have insufficient performance in optical applications requiring high transparency and heat resistance, and there is room for improvement. did.

International Publication No. 2014/098141 Pamphlet

  An object of the present invention is to provide a (meth) acrylic having excellent transparency and heat resistance obtained by a suspension polymerization method using a monomer mixture containing a macromonomer and an acrylate monomer and controlling the polymerization temperature conditions. An object of the present invention is to provide a polymer, a (meth) acrylic resin-based molding material containing the (meth) acrylic polymer, a method for producing them, and a method for producing a molded body obtained from the molding material.

The aforementioned problems are solved by the following present inventions [1] to [18].
[1] A (meth) acrylic resin-based molding material comprising a polymer containing a macromonomer (a) represented by the following general formula (A) as a monomer unit, which satisfies the following formula (1) (meta ) Acrylic resin molding material.
115 + K × (1000/3) ≦ Tc (1)
Tc: Mutation point temperature of (meth) acrylic resin molding material [° C.]
K: The natural logarithm of the storage elastic modulus E ′ [Pa] obtained by the following measurement method 1 is the vertical axis,
With the temperature T [° C.] as the horizontal axis, the slope of a straight line representing the following formula (2) obtained by the least square approximation method using the following formula (2) ln (E ′) = KT + C ₀ (2)
(C ₀ : constant)

Method for Measuring Mutation Point Temperature (Tc) and Storage Elastic Modulus E ′ Using a dynamic viscoelasticity measuring device (trade name: EXSTAR DMS 6100, manufactured by SII Nano Technology Co., Ltd.) for a polymer (molding material) test piece Using the measurement, the dynamic viscoelasticity of the test piece was measured under a nitrogen atmosphere at a frequency of 1 Hz, a temperature range of −100 to 200 ° C., and a temperature increase rate of 2 ° C./min. 'Get.
A straight line obtained by approximating a value from 50 ° C. to 80 ° C. with an exponential function when the storage elastic modulus E ′ measured by the above method is logarithmically plotted against the temperature, and a value of the storage elastic modulus E ′ in the glass transition region Let the temperature which shows the intersection of the straight line approximated by the exponential function be a mutation point temperature (Tc).
(R and R _{1 to} R _n are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group, and X _{1 to} X _n are each independently a hydrogen atom or (It is a methyl group. Z is a terminal group.)

[2] The (meth) acrylic resin according to [1], wherein the polymer is a copolymer of the macromonomer (a) represented by the general formula (A) and the acrylate monomer (b). Molding material.
[3] The polymer is a copolymer of the macromonomer (a) represented by the general formula (A), the acrylate monomer (b), and the methacrylic acid ester monomer (c). The (meth) acrylic resin-based molding material according to [1].
[4] The (meth) acrylic resin-based molding material according to any one of [1] to [3], wherein the weight average molecular weight (Mw) is 100,000 or more.
[5] The (meth) acrylic resin-based molding material according to any one of [1] to [4], wherein R and R _{1 to} R _{n in the} general formula (A) are all methyl groups.
[6] After starting the polymerization reaction of the mixture containing (a), (b) and (c) at a temperature T ₁ (° C.) satisfying the following formulas (3) and (4) under an inert atmosphere. the method of the polymer of performing heated to polymerization reaction temperature T ₂ satisfying the following formula ₍₅₎ (℃).
T _H -17 ≦ T ₁ ≦ T _H +13 (3)
T _H ≦ 82 (4)
( _TH : 10-hour half-life temperature of the polymerization initiator (° C))
T ₁ + 5 ≦ T ₂ ≦ 100 (5)
[7] The temperature is raised from the temperature T ₁ (° C.) to the temperature T ₂ (° C.) when the consumption rate of the macromonomer (a) is 20 to 75 wt% with respect to the charged amount. [6] The manufacturing method of the polymer as described in any one of.
[8] The method for producing a polymer according to [6] or [7], wherein the polymerization method is a suspension polymerization method.
[9] A mixture of (a), (b), (c) and the polymerization initiator is added to the aqueous suspension containing the particulates of the macromonomer (a) with (b), (c) and the polymerization initiator. The method for producing a polymer according to any one of [6] to [8], which is a mixture obtained by addition.
[10] A method for producing a molding material, wherein the polymer obtained by the production method according to any one of [6] to [9] is thermoformed.
[11] A method for producing a molded body, wherein a molded body is obtained from the molding material obtained by the manufacturing method according to [10].
[12] A polymer containing the macromonomer (a) represented by the general formula (A) as a monomer unit,
When the absolute molecular weight and intrinsic viscosity were measured in a good solvent using a gel permeation chromatograph, a light scattering detector, a differential refractive index detector, and a viscosity detector, the minimum value of X _i calculated from the following formula (6) A polymer in which X is 26 or less.
X _i = (log ₁₀ V _i -log ₁₀ V _{i + 1} ) /0.2×100 (6)
Here, each V _i (i = 1, 2, 3...) Is a value obtained by the following method.
Create a log-log graph with log ₁₀ M as the horizontal axis and log ₁₀ V as the vertical axis from the measurement results. The obtained graph is divided in steps of 0.2, and the left end of each division is M _i and the right end is M _{i + 1} . (That is, log ₁₀ Mi−log ₁₀ M _{i + 1} = 0.2). At this time, the intrinsic viscosity corresponding to Mi is Vi and the intrinsic viscosity corresponding to M _{i + 1} is Vi _{+ 1} .
[13] The (meth) acrylic polymer according to claim 12, wherein the polymer is a copolymer of the macromonomer (a) represented by the general formula (A) and the acrylate monomer (b). Polymer.
[14] The polymer is a copolymer of the macromonomer (a) represented by the general formula (A), the acrylate monomer (b), and the methacrylic acid ester monomer (c). The (meth) acrylic polymer according to claim 12.
[15] The polymer according to any one of claims 12 to 14, which has a weight average molecular weight (Mw) of 100,000 or more.
[16] The polymer according to any one of claims 12 to 14, wherein R and R _{1 to} R _{n in the} general formula (A) are all methyl groups.
[17] A method for producing a molding material, which comprises thermoforming the polymer according to any one of [12] to [16].
[18] A method for producing a molded body, wherein a molded body is obtained from the molding material obtained by the manufacturing method according to [17].

  According to the present invention, molding is highly transparent and excellent in heat resistance by using an acrylic copolymer obtained by using a monomer mixture containing a macromonomer (a) and an acrylate monomer (b). Material can be provided.

<Macromonomer (a)>
The macromonomer (a) is represented by the general formula (A). That is, the macromonomer (a) is obtained by adding a radically polymerizable group having an unsaturated double bond to one end of the poly (meth) acrylate segment. Here, the macromonomer is a polymer having a polymerizable functional group, and is also called a macromer. In the present invention, “(meth) acrylic acid” means “acrylic acid” or “methacrylic acid”.

In General Formula (A), R and R _{1 to} R _n can each independently have a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group.
Examples of the alkyl group for R or R _{1 to} R _n include a branched or straight chain alkyl group having 1 to 20 carbon atoms. Specific examples of the alkyl group for R or R _{1 to} R _n include a methyl group, an ethyl group, an n-propyl group, and an i-propyl group.

The cycloalkyl group of R or _R 1 to R _n, for example, a cycloalkyl group having 3 to 20 carbon atoms. Specific examples of the cycloalkyl group represented by R or R _{1 to} R _n include a cyclopropyl group, a cyclobutyl group, and an adamantyl group.

The aryl group of R or _R 1 to R _n, for example, an aryl group having 6 to 18 carbon atoms. Specific examples of the aryl group of R or R _{1 to} R _n include a phenyl group and a naphthyl group.
The substituents for R or R _{1 to} R _n are each independently an alkyl group, aryl group, carboxyl group, alkoxycarbonyl group (—COOR ′), carbamoyl group (—CONR′R ″), cyano group, hydroxyl group A group or atom selected from the group consisting of a group, an amino group, an amide group (—NR′R ″), a halogen, an allyl group, an epoxy group, an alkoxy group (—OR ′) or a group exhibiting hydrophilicity or ionicity Is mentioned. R ′ and R ″ are each independently the same group as R except for a heterocyclic group.

Examples of the alkoxycarbonyl group for the substituent of R or R _{1 to} R _n include a group having an alkoxy group having 1 to 12 carbon atoms, for example, a methoxycarbonyl group.

As the carbamoyl group for the substituent of R or R _{1 to} R _n , an N-mono (alkyl) carbamoyl group having 1 to 20 carbon atoms and an N, N-di (alkyl) carbamoyl group having 1 to 20 carbon atoms can be used. Examples thereof include N-methylcarbamoyl group and N, N-dimethylcarbamoyl group.
Examples of the amide group for the substituent of R or R _{1 to} R _n include an N-mono (alkyl) amide group having 1 to 20 carbon atoms and an N, N-di (alkyl) amide group having 1 to 20 carbon atoms. For example, a dimethylamide group is mentioned.
Examples of the halogen for the substituent of R or R _{1 to} R _n include fluorine, chlorine, bromine and elements.
As an alkoxy group of the substituent of R or R _{< 1 >} -Rn, a C1-C12 alkoxy group is mentioned, for example, A methoxy group is mentioned as a specific example.
Examples of the group exhibiting hydrophilicity or ionicity of the substituent of R or R _{1 to} R _n include, for example, alkali salts of carboxyl groups, poly (alkylene oxide) groups such as polyethylene oxide groups and polypropylene oxide groups, and quaternary ammonium bases. And the like, and the like.
R and R _{1 to} R _n are preferably at least one selected from an alkyl group and a cycloalkyl group, and a methyl group is more preferable from the viewpoint of availability.
X _{1 to} X _n are at least one selected from a hydrogen atom and a methyl group, and a methyl group is preferable.
X ₁ to X _n, from the viewpoint of easiness of synthesis of a macromonomer _(a), it is preferable more than half of the X 1 to X _n is a methyl group.
Z is a terminal group of the macromonomer (a). Examples of the terminal group of the macromonomer (a) include a group derived from a hydrogen atom and a radical polymerization initiator, similarly to the terminal group of a polymer obtained by known radical polymerization. Examples of the group derived from the radical polymerization initiator include a 1,1,3,3-tetramethylbutyl group, a cyanopropyl group, and a 2-methylpropionitrile group.

  Examples of the monomer for obtaining the macromonomer (a) include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and (meth) acrylate n. -Butyl, isobutyl (meth) acrylate, t-butyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, (meta ) Stearyl acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, 2-hydroxylethyl (meth) acrylate, 2-hydroxylpropyl (meth) acrylate, 2-hydroxylbutyl (meth) acrylate, ( (Meth) acrylic acid 3-hydroxylbutyl, (meth) acrylic acid 4-hydroxyl Chill, (meth) acrylic acid polyethylene glycol, (meth) acrylic acid polypropylene glycol, (meth) acrylic acid methoxyethyl, (meth) acrylic acid isobutoxyethyl, (meth) acrylic acid t-butoxyethyl, (meth) acrylic Phenoxyethyl acid, Nonylphenoxyethyl (meth) acrylate, 3-Methoxybutyl (meth) acrylate, Plaxel FM (Caprolactone addition monomer, trade name, manufactured by Daicel Chemical Industries, Ltd.), Blemmer PME-100 (NOF Corporation) Methoxypolyethylene glycol methacrylate (ethylene glycol chain is 2), trade name), Blemmer PME-200 (NOF Corporation methoxypolyethylene glycol methacrylate (ethylene glycol chain is 4)), trade name ) Nmer PME-400 (manufactured by NOF Corporation, methoxypolyethylene glycol methacrylate (ethylene glycol chain is 8), trade name), BLEMMER 50POEP-800B (manufactured by NOF Corporation, Octoxy polyethylene glycol-polypropylene glycol- Methacrylate (ethylene glycol chain is 8 and propylene glycol chain is 6), trade name) and BLEMMER 20ANEP-600 (NOF phenoxy (ethylene glycol-polypropylene glycol) monoacrylate, manufactured by NOF Corporation) Name), Blemmer AME-100 (trade name) manufactured by NOF Corporation, Blemmer AME-200 (trade name, manufactured by NOF Corporation), Blemmer 50AOEP-800B (trade name, manufactured by NOF Corporation) Is mentioned.

Among these, methacrylic acid esters are preferable from the viewpoint of easy availability of monomers, methyl methacrylate, n-butyl methacrylate, dodecyl methacrylate, stearyl methacrylate, 2-ethylhexyl methacrylate, methacrylic acid. Glycidyl, 2-hydroxyethyl methacrylate and 4-hydroxybutyl methacrylate are more preferable, and methyl methacrylate, n-butyl methacrylate and 2-ethylhexyl methacrylate are still more preferable.
Moreover, as a monomer for obtaining a macromonomer (a), the monomer composition containing said methacrylic acid ester and acrylic acid ester is preferable from the heat resistant point of the molding material obtained. Examples of the acrylate ester include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, and t-butyl acrylate. Among these, methyl acrylate is preferable from the viewpoint of availability.

  As content of the methacrylic acid ester in the said monomer composition, 80 mass% or more and 99 mass% or less are preferable from the heat resistant point of a molding material and a molded object. The lower limit of the methacrylic acid ester content is more preferably 82% by mass or more, and still more preferably 84% by mass or more. 98 mass% or less is more preferable, and, as for the upper limit of content of methacrylic acid ester, 95 mass% or less is still more preferable.

In the present invention, as the monomer unit of the macromonomer (a), an unsaturated carboxylic acid unit such as (meth) acrylic acid can be contained depending on the purpose.
Examples of the unsaturated carboxylic acid include (meth) acrylic acid, maleic acid, and maleic anhydride. As the monomer for obtaining the macromonomer (a), the above-mentioned monomers can be used alone or in combination of two or more.

  The Mw of the macromonomer (a) is preferably from 10,000 to 1,000,000 from the viewpoint of enhancing mechanical properties such as impact strength of the molded article of the present invention. The lower limit value of Mw of the macromonomer (a) is more preferably 15,000 or more, and further preferably 20,000 or more. Moreover, the upper limit of Mw of the macromonomer (a) is more preferably 500,000 or less, and further preferably 300,000 or less.

The macromonomer (a) can be produced by a known method. As a method for producing a macromonomer, for example, a method using a cobalt chain transfer agent (US Pat. No. 4,680,352), a method using an α-substituted unsaturated compound such as α-bromomethylstyrene as a chain transfer agent (International Publication No. 88/04304), a method of chemically bonding a polymerizable group (Japanese Patent Laid-Open No. 60-133007, US Pat. No. 5,147,952) and a method by thermal decomposition (Japanese Patent Laid-Open No. 11-240854) Is mentioned.
Among these, the production method of the macromonomer (a) is preferably a method using a cobalt chain transfer agent in that the number of production steps is small and a catalyst having a high chain transfer constant is used.

Examples of the method for producing the macromonomer (a) using a cobalt chain transfer agent include a bulk polymerization method, a solution polymerization method, and an aqueous dispersion polymerization method. Examples of the aqueous dispersion polymerization method include suspension polymerization method and emulsion polymerization method.
Among these, the aqueous dispersion polymerization method is preferable from the viewpoint of simplifying the recovery step of the macromonomer (a). In the aqueous dispersion polymerization method, water alone or a mixture of water and a water-soluble solvent (for example, ethanol) may be used as a solvent.

  Examples of the solvent used when the macromonomer (a) is obtained by the solution polymerization method include hydrocarbons such as toluene; ethers such as diethyl ether and tetrahydrofuran; halogenated hydrocarbons such as dichloromethane and chloroform; ketones such as acetone. Alcohols such as methanol; nitriles such as acetonitrile; vinyl esters such as ethyl acetate; carbonates such as ethylene carbonate; and supercritical carbon dioxide. These can be used alone or in combination of two or more.

  In the production of the molding material to be described later, the macromonomer (a) suspension synthesized by suspension polymerization is used even if the macromonomer (a) is used in the form of a powder or granular material recovered and purified. It may be used as it is. The granular material of the macromonomer (a) has, for example, an average particle diameter of 20 to 400 μm, preferably about 50 to 200 μm.

<Acrylic acid ester monomer (b)>
The acrylic ester monomer (b) of the present invention includes, for example, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, isobutyl acrylate, t-butyl acrylate, pentyl acrylate, hexyl acrylate, Examples include cyclohexyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, and the like. One or more of these can be appropriately selected and used as necessary.

<Methacrylate monomer (c)>
The methacrylic acid ester monomer (c) is, for example, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, pentyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate. , 2-ethylhexyl methacrylate, stearyl methacrylate and the like. One or more of these can be appropriately selected and used as necessary.

<Monomer mixture (I)>
The monomer mixture (a) for obtaining the polymer is macromonomer (a) 1 to 99% by mass, acrylic ester monomer (b) 1 to 99% by mass, methacrylic ester monomer (c) 0 to 98 mass% and a polymerization initiator are included. When combining the macromonomer (a), the acrylate monomer (b) and the methacrylic acid ester monomer (c), the Tc which is the mutation point temperature of the (meth) acrylic resin-based molding material is 115 ° C. or higher. It is preferable to select such that

  The content of the macromonomer (a) in the monomer mixture (a) is preferably 15% by mass or more and 60% by mass or less, and the mechanical strength and transparency of the molded article of the present invention can be improved. The upper limit of the content of the macromonomer (a) in the monomer mixture is more preferably 55% by mass or less, and 20% by mass or more and 50% by mass from the viewpoint that the heat resistance of the molding material and the molded product of the present invention can be improved. % Or less is more preferable. When using the suspension polymerization method, the content of the macromonomer (a) in the monomer mixture is preferably 25% by mass or more and 45% by mass or less from the viewpoint of dispersion stability.

  The content of the acrylate monomer (b) in the monomer mixture (a) is preferably 5% by mass or more and 60% by mass or less, and the flexibility of the molded article of the present invention can be improved. The lower limit of the content of the acrylate monomer (b) in the monomer mixture (a) is preferably 7% by mass or more. The upper limit of the content of the acrylate monomer (b) in the monomer mixture (a) is preferably 50% by mass or less.

A methacrylic acid ester monomer (c) can also be included in the monomer mixture. By setting the content of the methacrylic acid ester monomer (c) in the monomer mixture to be 0% by mass or more and 99% by mass or less, the transparency of the molded article of the present invention can be improved.
By setting the content of the methacrylic ester monomer (c) in the monomer mixture (a) to 10% by mass or more and 80% by mass or less, the transparency of the molded article of the present invention can be further improved. . The lower limit of the content of the methacrylic ester monomer (c) in the monomer mixture (I) is preferably 12% by mass or more. Moreover, 78 mass% or less of the upper limit of content of the methacrylic acid ester monomer (c) in a monomer mixture (I) is preferable.
Examples of the form of the monomer mixture include syrup in which the macromonomer (a) is dissolved in the acrylate monomer (b) or the acrylate monomer (b) and the methacrylic acid monomer (c). It is done.

<(Meth) acrylic resin-based molding material>
The molding material of the present invention is a (meth) acrylic molding material made of a polymer containing the macromonomer (a) represented by the general formula (A) as a monomer unit, and satisfies the following formula (1). It is a (meth) acrylic resin-based molding material. Examples of the form of the molding material of the present invention include pellets, beads and powder.
115 + K × (1000/3) ≦ Tc (1)
Tc: Mutation point temperature of the (meth) acrylic resin-based molding material K: Logarithm of storage elastic modulus E ′ [Pa] as the vertical axis and temperature T [° C.] as the horizontal axis
The slope of a straight line representing the following equation (2) obtained by the least square approximation method using the following equation (2) ln (E ′) = KT + C ₀ (2)
(C ₀ : constant)
Here, the formula (2) corresponds to the reaction rate constant in the so-called Arrhenius formula, and the polymerization temperature for obtaining the polymer is controlled to fall within the range of the formula (1). A molding material having both mechanical properties can be obtained.
The molding material satisfying the above-mentioned formula (1) can be obtained by polymerizing the monomer mixture under the temperature conditions described later.
The Mw of the molding material is preferably 30,000 or more and 5,000,000 or less from the viewpoint of the mechanical strength and thermal stability of the molding material. The lower limit of Mw of the molding material is more preferably 100,000 or more. Further, the upper limit value of Mw of the molding material is more preferably 1,000,000 or less.
Since the molding material can be obtained by a polymerization method without using a metal catalyst, it is suitable for obtaining a molded article and a molded article excellent in transparency.

<Manufacture of (meth) acrylic polymer and (meth) acrylic resin molding material>
As a method for producing the molding material, for example, [A] the macromonomer (a) is dissolved in syrup containing the acrylate monomer (b) and the like, and after adding the radical polymerization initiator, the dispersant is dissolved. A method of suspension polymerization of a syrup dispersion obtained by dispersing in an aqueous solution and [B] an aqueous suspension containing macromonomer (a) granules or a macromonomer (a) synthesized by suspension polymerization A method of obtaining a syrup suspension in which a dispersion of a monomer mixture is formed in an aqueous suspension and then adding an acrylate monomer (b) or the like, and subjecting the syrup suspension to suspension polymerization. It is done.

  In the said method, the molding material obtained with the manufacturing method of [A] exists in the tendency for what has the outstanding optical characteristic to be obtained. Moreover, in the manufacturing method of [B], since the collection | recovery process of a macromonomer (a) can be excluded, a manufacturing process can be shortened.

In any of the above methods, it is preferable to warm the macromonomer (a) when it is dissolved in the mixture containing the acrylate monomer (b) and the like.
The heating temperature for dissolving the macromonomer (a) in the monomer mixture is preferably 30 ° C. or higher and 90 ° C. or lower. When the heating temperature is 30 ° C. or higher, the solubility of the macromonomer (a) tends to be good, and when the heating temperature is 90 ° C. or lower, volatilization of the acrylate monomer (b) and the like can be suppressed. There is a tendency. The lower limit value of the heating temperature is more preferably 35 ° C. or higher, and the upper limit value of the heating temperature is more preferably 75 ° C. or lower.
When the radical polymerization initiator is used when polymerizing the acrylate monomer (b) or the like in which the macromonomer (a) is dissolved, the macromonomer (a) is acrylic as the addition time of the radical polymerization initiator. It is preferable to add after dissolving in the acid ester monomer (b) or the like.

  The temperature at which the radical polymerization initiator is added is preferably 0 ° C. or higher (10-hour half-life temperature of radical polymerization initiator −15 ° C.) or lower. When the temperature at which the radical polymerization initiator is added is 0 ° C. or higher, the solubility of the radical polymerization initiator in the monomer tends to be good. Moreover, it exists in the tendency which can perform stable superposition | polymerization at the temperature at the time of adding a radical polymerization initiator (10-hour half-life temperature of a radical polymerization initiator -15 degreeC) or less.

Examples of the polymerization initiator include radical polymerization initiators such as organic peroxides and azo compounds.
Specific examples of the organic peroxide include 2,4-dichlorobenzoyl peroxide, t-butyl peroxypivalate, o-methylbenzoyl peroxide, bis-3,5,5-trimethylhexanoyl peroxide, octa Noyl peroxide, t-butylperoxy-2-ethylhexanoate, cyclohexanone peroxide, benzoyl peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, lauroyl peroxide, diisopropylbenzene hydroperoxide, t-butyl hydroperoxide and A di-t-butyl peroxide is mentioned.
Specific examples of the azo compound include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile). And 2,2′-azobis (2,4-dimethyl-4-methoxyvaleronitrile).

Among the above radical polymerization initiators, benzoyl peroxide, 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile) and 2,2′-azobis (2,4-dimethyl-4-methoxyvaleronitrile) are preferred. A radical polymerization initiator can be used individually or in combination of 2 or more types.
The amount of radical polymerization initiator added is 100 parts by mass with respect to the total amount of the macromonomer (a), the acrylate monomer (b) and the methacrylic acid ester monomer (c) in terms of controlling the heat generation of polymerization. 0.0001 mass part or more and 10 mass parts or less are preferable.

As the polymerization temperature, the polymerization reaction is started at a temperature T ₁ (° C.) satisfying the following formulas (3) and (4) in an inert atmosphere for the mixture containing (a), (b) and (c). After that, it is preferable to perform the polymerization reaction by raising the temperature to a temperature T ₂ (° C.) that satisfies the following formula (5).
T _H -17 ≦ T ₁ ≦ T _H +13 (3)
T _H ≦ 82 (4)
( _TH : 10-hour half-life temperature of the polymerization initiator (° C))
T ₁ + 5 ≦ T ₂ ≦ 100 (5)

Switching from T ₁ (° C.) to T ₂ (° C.) is performed when the consumption rate of the macromonomer (a) represented by the general formula (A) is 20 to 75%, from T ₁ (° C.) to T ₂ (° C.). Then, the transparency and heat resistance of the molded product of the present invention can be improved by setting the second step to maintain the temperature of T ₂ (° C.).
At this time, the consumption rate of the macromonomer (a) represented by the general formula (A) is 40 to 75%, the consumption rate of the methacrylic ester monomer is 60 to 95%, and the consumption of the acrylate monomer By raising the temperature to T ₂ (° C.) represented by the formula (5) while the rate is 35 to 85% and then maintaining the temperature of T ₂ (° C.), The transparency and heat resistance of the molded product can be further improved.

When T ₁ is T _H −17 ° C. or higher, the polymerization reaction efficiency can be sufficiently achieved, and by setting T ₁ to T _H + 13 ° C. or lower, runaway polymerization can be prevented.
Further, by setting T ₂ to T ₁ + 5 ° C. or higher, the acrylate monomer (b) remaining in the molding material can be reduced. T ₂ can be carried out by the 100 ° C. or less, a stable polymerization.

  This step is preferably performed by suspension polymerization. Examples of the dispersant used for the suspension polymerization include an alkali metal salt of poly (meth) acrylic acid, a copolymer of an alkali metal salt of (meth) acrylic acid and (meth) acrylic acid ester, and (meth) acrylic acid sulfone. Copolymers of alkyl alkali metal salts and (meth) acrylic acid esters, polystyrene sulfonic acid alkali metal salts, styrene sulfonic acid alkali metal salts and (meth) acrylic acid ester copolymers, or of these monomers Copolymers composed of combinations; polyvinyl alcohol having a saponification degree of 70 to 100%, methyl cellulose, starch and hydroxyapatite. These can be used alone or in combination of two or more. Among these, (meth) acrylic acid sulfoalkyl and alkali metal salt and (meth) acrylic acid ester copolymer and (meth) acrylic acid alkali metal salt, which have good dispersion stability during suspension polymerization ( A copolymer of (meth) acrylic acid ester is preferred. The content of the dispersant in the aqueous suspension is 0.005 to 0.05% by mass with respect to the amount of the monomer mixture. As a dispersing agent used for suspension polymerization, water and alcohol are mentioned, for example.

In the present invention, an electrolyte such as sodium carbonate, sodium sulfate or manganese sulfate may be added to the aqueous suspension as another additive for the purpose of improving the dispersion stability of the aqueous suspension.
In the present invention, a polymer can be obtained by polymerizing a raw material composition containing a sulfur-containing chain transfer agent described later in a monomer mixture.

  For suspension polymerization, a chain transfer agent can be used depending on the purpose. Examples of chain transfer agents include mercaptans, α-methylstyrene dimers, and terpenoids.

<Molded body>
The molded body of the present invention is obtained from the molding material of the present invention.
Examples of the shape of the molded body of the present invention include three-dimensional shapes such as sheets and films.
Examples of the molding method for obtaining the molded article of the present invention include an injection molding method, a compression molding method, a hollow molding method, an extrusion molding method, a rotational molding method, a casting method, and a solvent casting method.

  In the molded product of the present invention, the molding material of the present invention can be used alone or in combination of two or more. Other polymers other than the molding material of the present invention can be added to the molded article of the present invention as required by the present invention. Examples of other polymers include acrylic polymers such as polymethyl methacrylate, polyolefins, polyamides, unsaturated polyesters, saturated polyesters such as polyethylene terephthalate and polybutylene terephthalate, and polycarbonates.

  Examples of the method of mixing the molding material of the present invention with other polymers include a physical mixing method such as a Henschel mixer and a blender and a melt mixing method such as an extruder.

  In the molded product of the present invention, various stabilizers such as antioxidants, ultraviolet absorbers, heat stabilizers, etc., as necessary for the molding material of the present invention; colorants such as inorganic pigments, organic pigments, dyes; carbon black, It can be molded by blending conductivity imparting agents such as ferrite; and various additives such as inorganic fillers, lubricants, plasticizers, organic peroxides, neutralizing agents, and crosslinking agents.

<(Meth) acrylic polymer>
The (meth) acrylic polymer of the present invention is a (meth) acrylic polymer comprising a polymer containing the macromonomer (a) represented by the formula (A) as a monomer unit, the gel When the absolute molecular weight M and intrinsic viscosity V of the (meth) acrylic polymer in a good solvent were measured using a permeation chromatograph, a light scattering detector, a differential refractive index detector, and a viscosity detector, the following formula ( It is a polymer having a minimum value X of 26 or less among each Xi calculated from γ).
Xi = (logV _i −logV _{i + 1} ) /0.2×100 (γ)
Here, each V _i (i = 1, 2, 3...) Is a value obtained by the following method.
From the measurement results, a log-log graph is created with log M as the horizontal axis and log V as the vertical axis. The obtained graph is divided into 0.2 increments, and the left end of each division is M _i and the right end is M _{i + 1} (ie, log Mi− partitioning so that logMi + 1 = 0.2.), intrinsic viscosity the intrinsic viscosity corresponding to this time _{M i} corresponds _Vi, to _{M i + 1} is _{V i + 1.}

  X reflects the structure of the polymer, and the smaller the minimum value of X measured and calculated by the method described in the text, the higher the degree of branching of the polymer. As the degree of branching of the polymer is higher, a molding material having a better balance between molding processability and mechanical properties can be obtained. In the present invention, the minimum value of X is preferably 26 or less, and more preferably 24 or less.

  In the present invention, the absolute molecular weight and intrinsic viscosity are obtained by separating the polymer using a gel permeation chromatograph and detecting the eluted components with a light scattering detector, a differential refractive index detector and a viscosity detector. The absolute molecular weight of each elution position (elution time or elution volume) is obtained by using a light scattering detector and a differential refractive index detector together, and the intrinsic viscosity at each elution position is obtained by using a differential refractive index detector and a viscosity detector together. Is required.

  The gel permeation chromatograph, light scattering detector, differential refractive index detector and viscosity detector may all be connected in series, or each detector may be connected in parallel to the gel permeation chromatograph. The gel permeation chromatograph and each detector may be connected in pairs. From the viewpoint of obtaining the absolute molecular weight and intrinsic viscosity at once and from the viewpoint of reproducibility, it is preferable to connect them all in series.

  In the present invention, a good solvent is a solvent that dissolves a polymer to form a homogeneous system. The good solvent may be selected with reference to various documents (polymer handbook, etc.), and the absolute molecular weight and the intrinsic viscosity of the macromonomer and the homopolymer of each monomer are measured in the same manner as in the present invention. An eluent composition in which the slope of the approximate line when the logarithm is plotted on the horizontal axis and the logarithm of intrinsic viscosity is plotted on the vertical axis may be used as a good solvent.

  Hereinafter, the present invention will be described with reference to examples. In the following, “part” means “part by mass”. In addition, the consumption rate of raw material monomers and the consumption rate of macromonomer in the polymerization process, polymer weight average molecular weight (Mw), number average molecular weight (Mn), haze of molded product, total light transmittance and viscoelasticity, absolute molecular weight of polymer and The intrinsic viscosity was evaluated by the following method.

(1) Residual amount of raw material monomer and consumption rate Immediately after the start of the polymerization, 1 g of a uniform solution of the polymerization solution was extracted at 10 minute intervals with a micropipette and dissolved in 40 g of acetone to obtain a sampling solution. 500 μl of an internal standard solution (butyl acetate 2 ml / acetone 100 ml) was added to the sampling solution sampled at each time to prepare a gas chromatography measurement solution. The gas chromatographic measurement solution was measured using a gas chromatograph (Agilent (product), GC6890) under the following conditions, and the residual amount of the raw material monomer in the polymerization solution was determined from a calibration curve prepared in advance.
Column type: DB-5
Inlet temperature: 150 ° C
Oven temperature: 50-200 ° C
Detector temperature: 250 ° C
Split ratio: 10: 1
Linear velocity: 40 cm / sec
From the residual amount of the raw material monomer determined by gas chromatography, the consumption rate of the raw material monomer at each polymerization time was determined by the following formula.

Consumption rate of raw material monomer (%) =
((Feed amount of raw material monomer−remaining amount of raw material monomer) / feed amount of raw material monomer) × 100

(2) Consumption rate of macromonomer Immediately after the start of polymerization, 1 g of a uniform solution of the polymerization solution was extracted at 10 minute intervals with a micropipette and dissolved in 5 g of acetone to obtain a sampling solution. 5 g of deuterated chloroform was added to the sampling solution, stirred well, and only a deuterated chloroform solution in which organic substances were transferred was obtained using a separatory funnel to obtain a sample solution for NMR measurement. The NMR measurement sample solution was subjected to ¹ H-NMR measurement under the following conditions using a nuclear magnetic resonance apparatus (Varian, manufactured by 500 Hz) to obtain an NMR spectrum.
Integration count: 10,000 times Measurement temperature: 40 ° C
From the obtained NMR spectrum, the ratio of the area of the peak peak of the macromonomer terminal double bond (6.21 ppm, 5.46 ppm) and the area of the deuterated chloroform spectrum peak (7.24 ppm) was determined from each polymerization. The consumption rate of the macromonomer in the sampling solution over time was determined.

(3) Weight average molecular weight (Mw) and number average molecular weight (Mn)
The weight average molecular weight (Mw) and number average molecular weight (Mn) of the (meth) acrylic polymer were measured under the following conditions using a gel permeation chromatograph (GPC) (Tosoh Corp., HLC-8320). .
Column: TSK GUARD COLUMN SUPER HZ-L (4.6 × 35 mm) and two TSK-GEL SUPER HZM-N (6.0 × 150 mm) connected in series Eluent: Tetrahydrofuran Measurement temperature: 40 ° C.
Flow rate: 0.6 mL / min In addition, Mw and Mn are the standard samples (four types of peak top molecular weights 141,500, 55,600, 10,290, and 1,590) made by Polymer Laboratories. It was obtained using a calibration curve prepared using the above.

(4) Haze The haze of the molded body was measured according to JIS K7136.

(5) Total light transmittance The total light transmittance of the molded body was measured according to JIS K7136.

(6) Calculation method of storage elastic modulus E ′ and mutation point temperature (Tc) The temperature dependence of storage elastic modulus E ′ of (meth) acrylic resin-based molding material is determined by a dynamic viscoelasticity measuring device (SII Nanotechnology). (Exstar DMS6100 manufactured by Co., Ltd.) was measured under the measurement conditions of a frequency of 1 Hz, a temperature range of −100 to 200 ° C., and a heating rate of 2 ° C./min to obtain a storage elastic modulus (E ′)-temperature curve. It was. A straight line approximating the value of 50 ° C. to 80 ° C. with an exponential function when the storage elastic modulus E ′ measured by the above method is plotted logarithmically with temperature, and the value of the storage elastic modulus in the glass transition region as an exponential function The temperature indicating the intersection point of the straight lines approximated in (3) was defined as the mutation point temperature (Tc).

(7) Judgment of Formula (1) 50 to 80 degreeC of the following formula (2) obtained by plotting the storage elastic modulus E '[Pa] measured by the above method logarithmically with respect to temperature T [° C] It is determined whether the slope K of the straight line and the mutation point temperature Tc satisfy the following expression (1). If the expression (1) is satisfied, “◯” is satisfied, and if the expression (1) is not satisfied, “×” is determined. .
115 + K × 1000/3 ≦ Tc (1)
ln (E ′) = KT + C ₀ (C ₀ : intercept) (2)

(8) Measuring method of absolute molecular weight M and intrinsic viscosity V The absolute molecular weight M and intrinsic viscosity V of the (meth) acrylic polymer were measured under the following conditions using a gel permeation chromatograph (GPCmax manufactured by Viscotek).
Column: One TSKgel guardcolumn MP (XL) (6.0 × 40 mm, manufactured by Tosoh Corporation) and two TSKgel MultiporeHXL-M (5 μm, 7.8 × 300 mm, manufactured by Tosoh Corporation) connected in series Elution Liquid: Tetrahydrofuran Column and detector temperature: 40 ° C
Flow rate: 1.0 mL / min Detector: TDA302 (manufactured by Viscotek)
Sample concentration: 4 mg / mL (polymer is dissolved in tetrahydrofuran)
Injection volume: 200 μL
Standard product for instrument calibration: Polystyrene (manufactured by Viscotek, molecular weight 105,000)
The absolute molecular weight and intrinsic viscosity at each elution position were calculated using software (OmniSEC) attached to the apparatus. In the molecular weight range where the logarithm (log ₁₀ M) of the absolute molecular weight is 4 or more, a log-log graph is created with log ₁₀ M as the horizontal axis and log ₁₀ V as the vertical axis, and the obtained graph is divided in increments of 0.2. In this case, the left end of each section is M _i and the right end is M _{i + 1} (that is, log ₁₀ M _i -log ₁₀ M _{i + 1} = 0.2). At this time, the intrinsic viscosity corresponding to Mi is Vi, Mi + 1. The intrinsic viscosity corresponding to is set to Vi + 1.
Extracting a plurality of Vis having absolute molecular weights M1 and M2 at the elution position satisfying log ₁₀ M _i -log ₁₀ M _{i + 1} = 0.2, and using intrinsic viscosity V1 at M1 and intrinsic viscosity V2 at M2, The minimum value of X was calculated from equation (6).

Xi = (log ₁₀ V _i -log ₁₀ V _{i + 1} ) /0.2×100 (6)

The calculated minimum value of X is “◎” when it is 24 or less, “◯” when it exceeds 24 and 26 or less, and “x” when it exceeds 26.

[Production Example 1]
<Synthesis of Dispersant (1)>
In a 1200 L reaction vessel equipped with a stirrer, a condenser, and a thermometer, 61.6 parts of a 17% aqueous potassium hydroxide solution, methyl methacrylate (trade name: Acryester M) manufactured by Mitsubishi Rayon Co., Ltd. And 19.3 parts of deionized water were charged. Subsequently, the liquid in the reaction apparatus was stirred at room temperature, and after confirming an exothermic peak, it was further stirred for 4 hours. Thereafter, the reaction solution in the reaction apparatus was cooled to room temperature to obtain a potassium methacrylate aqueous solution.
Next, in a reaction solution having a capacity of 1050 L equipped with a stirrer, a condenser tube and a thermometer, 9000 parts of deionized water and a 42% by weight aqueous solution of 2-sulfoethyl sodium methacrylate (manufactured by Mitsubishi Rayon Co., Ltd., trade name: (Acryester SEM-Na) 60 parts, 10 parts of the above-mentioned potassium methacrylate aqueous solution and 12 parts of methyl methacrylate were stirred and heated to 50 ° C. while replacing the inside of the polymerization apparatus with nitrogen.
In addition, 0.08 part of 2,2′-azobis (2-methylpropionamidine) dihydrochloride (manufactured by Wako Pure Chemical Industries, Ltd., trade name: V-50) is added as a polymerization initiator, The temperature was raised to 60 ° C. After the temperature increase, methyl methacrylate was continuously added dropwise at a rate of 0.24 parts / minute for 75 minutes. The reaction solution was kept at 60 ° C. for 6 hours and then cooled to room temperature to obtain a 10 wt% solid dispersion (1) as a transparent aqueous solution.

[Production Example 2]
<Synthesis of chain transfer agent (1)>
In a synthesizer equipped with a stirrer, 2.00 g (8.03 mmol) of cobalt (II) acetate tetrahydrate (manufactured by Wako Pure Chemical Industries, Ltd., Wako Special Grade) and nitrogen bubbling in advance under a nitrogen atmosphere. 100 ml of oxygenated diethyl ether was added and stirred at room temperature for 2 hours.
Next, 20 mL of boron trifluoride diethyl ether complex (manufactured by Tokyo Chemical Industry Co., Ltd., EP grade) was added, and the mixture was further stirred for 6 hours. The obtained product was filtered, and the obtained filtrate was washed with diethyl ether, dried at 100 MPa or less at 20 ° C. for 12 hours, and 5.02 g (7.93 mmol, yield of brown solid chain transfer agent (1)). 99 mass%) was obtained.

[Production Example 3]
<Synthesis of Macromonomer (a-1)>
In a polymerization apparatus equipped with a stirrer, a condenser tube and a thermometer, 145 parts of deionized water, 0.13 part of sodium sulfate, and 0.26 part of a 10% solids dispersion (1) produced in Production Example 1 were placed. And stirred to obtain a uniform aqueous solution. Next, 100 parts of methyl methacrylate (same as above), 0.0009 part of chain transfer agent (1) produced in Production Example 2, and Perocta O (manufactured by NOF Corporation, 1,1,3,3) -Tetramethylbutylperoxy 2-ethylhexanoate (trade name) 0.1 part was added to obtain an aqueous dispersion.
Next, the inside of the polymerization apparatus was sufficiently purged with nitrogen, and the aqueous dispersion was heated to 80 ° C. and held for 4 hours, and then heated to 92 ° C. and held for 2 hours. Thereafter, the reaction solution was cooled to 40 ° C. to obtain an aqueous suspension of macromonomer. This aqueous suspension was filtered through a filter cloth, and the filtrate was washed with deionized water and dried at 40 ° C. for 16 hours to obtain a reaction product. The amount of terminal double bonds introduced into the reaction product was almost 100%, and from the NMR measurement results, it was confirmed that the reaction product was the macromonomer (a-1). The resulting macromonomer (а-1) had a bead shape. The bead shape had an average particle size of 95 μm, Mw of 32,100, and Mn of 17,000.

[Example 1]
A suspension water dispersion medium was prepared by mixing 145 parts of deionized water, 0.13 part of sodium sulfate and 0.26 part of the dispersant (1) produced in Production Example 1.
In a separable flask with a cooling tube, 40 parts of macromonomer (a-1), 36 parts of acrylic acid monomer (b) as n-butyl acrylate (Mitsubishi Chemical Corporation), methacrylic acid ester monomer As (c), 24 parts of methyl methacrylate (same as above) was charged and heated to 50 ° C. with stirring to obtain a raw material syrup. After cooling the raw syrup to 40 ° C. or less, 0.5 part of 2,2′-azobis (isobutyronitrile) (trade name: V-60, manufactured by Wako Pure Chemical Industries) is dissolved in the raw syrup as a polymerization initiator. Got syrup.
After adding the above-mentioned aqueous dispersion medium for suspension to syrup, the atmosphere in the separable flask was replaced with nitrogen by nitrogen bubbling, and the stirring rotation speed was increased to obtain a syrup dispersion. Next, the syrup dispersion was heated to 75 ° C. (hereinafter, the first step). Sampling is performed at 10-minute intervals from the start of temperature rise (heating time 0 minutes), the consumption rate of the acrylate monomer and methacrylate monomer is evaluated by gas chromatography measurement, and the macromonomer is measured by NMR measurement. The consumption rate was calculated.
When the macromonomer consumption rate is 44%, the acrylate monomer consumption rate is 38%, and the methacrylate monomer consumption rate is 63%, the temperature of the syrup dispersion is increased to 85 ° C. (Hereinafter, the second step). In 300 minutes after the syrup dispersion reached 50 ° C. in the first step, the polymerization was terminated to obtain a suspension. Sampling was performed at the end of the polymerization, and the residual amount of the acrylate monomer was evaluated by gas chromatography measurement.
After the suspension is cooled to 40 ° C. or lower, the suspension is filtered with a filter cloth, the filtrate is washed with deionized water, and dried at 40 ° C. for 16 hours to obtain a molding material (A-1). It was. Mw of the molding material (A-1) was 222,500. The molding material (A-1) is injection-molded by a small injection molding machine baby plast 6 / 10P (injection piston diameter 16φ) manufactured by Lambardi, and a molded body (1- 1 mm) having a width of 30 mm, a length of 30 mm and a thickness of 2 mm. 1) and a molded body (1-2) having a width of 5 mm, a length of 50 mm, and a thickness of 2 mm were obtained. The molded body (1-1) had a haze of 2.3% and a total light transmittance of 90.8%. The dynamic viscoelasticity measurement of the molded body (1-2) was carried out, the mutation point temperature Tc was determined from the temperature storage-elastic modulus curve, and it was determined whether the expression (1) was satisfied. It was in the range.
Further, the absolute molecular weight M and intrinsic viscosity V of the (meth) acrylic polymer were measured by the above-mentioned method, and the minimum value X was calculated using the formula (6). . The evaluation results are shown in Tables 1 and 2.

[Example 2]
Except for using 2,2′-azobis (2,4-dimethylvaleronitrile) Wako Pure Chemicals, trade name: V-65) as a polymerization initiator for the molding material (A), the same as in Example 1 A molding material (A-2) and molded bodies (2-1, 2-2) were obtained. The evaluation results are shown in Tables 1 and 2.

[Example 3]
Except that the polymerization temperature of the molding material (A) was changed to a constant 85 ° C. from the initial stage of polymerization, the molding material (A-3) and the moldings (3-1, 3-2) were obtained in the same manner as in Example 1. It was. The evaluation results are shown in Tables 1 and 2.
The haze of the obtained molded body (3-1) was higher than the haze of the molded body obtained in Examples 1 and 2.

[Comparative Example 1]
The molding material (A-1 ′) and the molded body (1-1 ′) were the same as in Example 1 except that the temperature raising timing of the molding material (A) to the second step was changed to the conditions shown in Table 1. 1-2 ′). The evaluation results are shown in Tables 1 and 2.
When obtaining the molding material (A-1 ′), the temperature rise to the second step was too late, so that the obtained molding (1-1 ′) became cloudy.

[Comparative Example 2]
The molding material (A-2 ′) and the molded body (2-1 ′) were the same as in Example 1 except that the temperature raising timing of the molding material (A) to the second step was changed to the conditions shown in Table 1. 2-2 ′). The evaluation results are shown in Tables 1 and 2.
When obtaining the molding material (A-2 ′), the temperature rise to the second step was too late, so that the obtained molding (2-1 ′) became cloudy.

[Comparative Example 3]
Except for changing the polymerization temperature of the molding material (A) to a constant value of 75 ° C. from the initial stage of polymerization, the molding material (A-3 ′) and the molded body (3-1 ′, 3-2 ′) were obtained in the same manner as in Example 1. ) The evaluation results are shown in Tables 1 and 2.
When the molding material (A-3 ′) was obtained, the polymerization temperature was low throughout the polymerization, so that the residual amount of the acrylate monomer (b) after the polymerization was increased.

[Comparative Example 4]
When producing the molding material (A), the molding material (A-4 ′) and the molding (4-1 ′) were the same as in Example 1 except that the macromonomer (a) was changed to the compounds shown in Table 1. 4-2 ′). The evaluation results are shown in Tables 1 and 2. When the molding material (A-4 ′) is obtained, since the macromonomer (a) is not used, the n-butyl acrylate component and the methyl methacrylate component are completely compatible, and the molded body (4-2 ′). Thus, the evaluation of the mutation point temperature Tc became impossible and the heat resistance decreased.

Claims (18)

A (meth) acrylic resin-based molding material comprising a (meth) acrylic polymer containing a macromonomer (a) represented by the following general formula (A) as a monomer unit,
A (meth) acrylic resin-based molding material that satisfies the following formula (1).
115 + K × (1000/3) ≦ Tc (1)
Tc: Mutation point temperature [° C.] obtained by the following measurement method 1
K: The natural logarithm of the storage elastic modulus E ′ [Pa] obtained by the following measurement method 1 is the vertical axis,
Approximating the temperature T [° C] by the least square method with the following equation (2) with the horizontal axis.
Inclination of a straight line representing the following formula (2) ln (E ′) = KT + C ₀ (2)
(C ₀ is a constant)
[Measurement method 1]
About a test piece of a (meth) acrylic resin-based molding material, using a dynamic viscoelasticity measuring device, under a nitrogen atmosphere, a frequency of 1 Hz, a temperature range of −100 to 200 ° C., and a temperature rising rate of 2 ° C./min. Dynamic viscoelasticity measurement is performed to obtain a storage elastic modulus E ′ [Pa].
The storage elastic modulus E ′ [Pa] measured by the above method is logarithmically plotted with respect to the temperature [° C.], and the value of the storage elastic modulus E ′ from the temperature 50 ° C. to 80 ° C. is approximated by an exponential function. And the temperature at which the intersection of the storage elastic modulus E ′ in the glass transition region and a straight line approximated by an exponential function is defined as a mutation point temperature (Tc).
(R and R _{1 to} R _n are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group, and X _{1 to} X _n are each independently a hydrogen atom or (It is a methyl group. Z is a terminal group.)   The said polymer is a copolymer containing the structural unit derived from the macromonomer (a) represented by the said general formula (A), and the repeating unit derived from an acrylate ester monomer (b). (Meth) acrylic resin-based molding material.   The polymer is a structural unit derived from the macromonomer (a) represented by the general formula (A), an acrylic ester monomer (b), and a repeating unit derived from the methacrylic ester monomer (c). The (meth) acrylic resin-based molding material according to claim 1, which is a copolymer containing.   The (meth) acrylic resin-based molding material according to any one of claims 1 to 3, wherein the weight average molecular weight (Mw) is 100,000 or more. The (meth) acrylic resin-based molding material according to any one of claims 1 to 4, wherein R and R _{1 to} R _{n in the} general formula (A) are all methyl groups. A method for producing a (meth) acrylic polymer using a macromonomer (a) represented by the following general formula (A), an acrylate monomer (b) and a methacrylic acid ester monomer (c). Then, after starting the polymerization reaction at a temperature T ₁ (° C.) satisfying the following formulas (3) and (4) in an inert atmosphere, the mixture containing (a), (b) and (c) is formula (5) a method of manufacturing a polymer performing heated to polymerization reaction temperature T _{2 (°} C.) which satisfies.
T _H -17 ≦ T ₁ ≦ T _H +13 (3)
T _H ≦ 82 (4)
( _TH : 10-hour half-life temperature of the polymerization initiator (° C))
T ₁ + 5 ≦ T ₂ ≦ 100 (5)
(R and R _{1 to} R _n are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group, and X _{1 to} X _n are each independently a hydrogen atom or (It is a methyl group. Z is a terminal group.) The temperature rise from the temperature T ₁ (° C.) to the temperature T ₂ (° C.) is performed while the consumption rate of the macromonomer (a) is 20 to 75 wt% with respect to the charged amount. Of (meth) acrylic polymer production method.   The method for producing a (meth) acrylic polymer according to claim 6 or 7, wherein the polymerization method is a suspension polymerization method.   The (meta) according to any one of claims 6 to 8, wherein the mixture is a mixture obtained by adding the (b) and (c) to an aqueous suspension containing a granular material of the macromonomer (a). ) A method for producing an acrylic polymer.   The manufacturing method of the (meth) acrylic-resin-type molding material which heat-molds the (meth) acrylic-type polymer obtained by the manufacturing method in any one of Claims 6-9.   The manufacturing method of a molded object which obtains a molded object from the (meth) acrylic-resin-type molding material obtained by the manufacturing method of Claim 10. A polymer containing a macromonomer (a) represented by the following general formula (A) as a monomer unit, and calculated from the following formula (6) using the intrinsic viscosity V _i obtained by the following measuring method 2. minimum value X is 26 or less (meth) acrylic resin-based polymer was X _i.
X _i = (logV _i −logV _{i + 1} ) /0.2×100 (6)
(I = 1, 2, 3 ...)
(R and R _{1 to} R _n are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group, and X _{1 to} X _n are each independently a hydrogen atom or A methyl group, Z is a terminal group;

[Measurement method 2]
Using a gel permeation chromatograph equipped with a light scattering detector, a differential refractive index detector, and a viscosity detector, in the good solvent of the (meth) acrylic polymer, the absolute molecular weight of the (meth) acrylic polymer M and intrinsic viscosity V are measured. The measurement results are plotted on a log-log graph with log M as the horizontal axis and log V as the vertical axis. The horizontal axis of the obtained graph is divided into 0.2 increments, and the value of M at the left end of each division is set to M _i and the right end. Let M _{i + 1} be M _{i + 1} (ie, logM _i −logM _{i + 1} = 0.2). At this time, the intrinsic viscosity corresponding to the absolute molecular weight M _i is V _i , and the intrinsic viscosity corresponding to the absolute molecular weight M _{i + 1} is V _{i + 1} .   The (meth) acrylic polymer is a copolymer containing a structural unit derived from the macromonomer (a) represented by the general formula (A) and a repeating unit derived from the acrylate monomer (b). The polymer according to claim 12.   The (meth) acrylic polymer is a structural unit derived from the macromonomer (a) represented by the general formula (A), a repeating unit derived from the acrylate monomer (b), and a single amount of methacrylic acid ester. The (meth) acrylic polymer according to claim 12, which is a copolymer containing a repeating unit derived from the body (c).   The (meth) acrylic polymer according to any one of claims 12 to 14, having a weight average molecular weight (Mw) of 100,000 or more. The (meth) acrylic polymer according to any one of claims 12 to 15, wherein R and R _{1 to} R _{n in the} general formula (A) are all methyl groups.   The manufacturing method of the (meth) acrylic-resin-type molding material which heat-molds the (meth) acrylic-type polymer in any one of Claims 12-16, and obtains a molded object.   The manufacturing method of a (meth) acrylic resin-type molded object which obtains a molded object from the (meth) acrylic resin-type molding material obtained with the manufacturing method of Claim 17.