JP5760367B2 - Polymerizable composition, acrylic film and optical member - Google Patents

Description

  The present invention relates to a polymerizable composition, an acrylic film, and an optical member.

  Acrylic resins are used in various applications such as lenses, automobile parts, lighting parts, and displays due to their excellent optical properties. However, when used as a film, ordinary acrylic resins have the disadvantage of being low in flexibility and fragile.

  As a flexible acrylic film, for example, Patent Document 1 proposes a light guide plate for a surface light source device using a film having a thickness of 100 μm to 700 μm in which rubber particles are dispersed in methacrylic resin.

JP 2008-218207 A

  However, when an attempt is made to punch the film described in Patent Document 1, whitening may occur on the end face of the film obtained by the punching process, which causes a problem in workability.

  In view of the above-mentioned problems, the present inventors have further provided a acrylic film excellent in flexibility and transparency in which cracking and whitening due to punching are suppressed, and in addition to punching workability and transparency. In order to improve heat resistance, intensive studies were conducted.

  The objective of this invention is providing the polymeric composition which can form the acrylic film excellent in workability, flexibility, transparency, and heat resistance. Another object of the present invention is to provide an acrylic film excellent in processability, flexibility, transparency and heat resistance obtained by polymerizing the polymerizable composition, and an optical member using the acrylic film.

The polymerizable composition according to one embodiment of the present invention has the following general formula (1):
^{_{CH 2 = CR 1 -COO-X}} -COCR 1 = CH 2 (1)
Wherein X is a divalent group having a number average molecular weight of 500 or more and containing at least one selected from repeating units of polyalkylene glycol, repeating units of polyester diol and repeating units of polycarbonate diol, and R ¹ is H or CH _{Shows 3} ]
Di (meth) acrylate (A) represented by:
Mono (meth) acrylate (B);
A thermoplastic polymer (C) having a glass transition temperature (Tg) of 100 ° C. or higher and soluble in a mixture of the di (meth) acrylate (A) and the mono (meth) acrylate (B);
And a polymerization initiator (α).

  The polymerizable composition according to another aspect of the present invention is the above-described polymerizable composition, wherein the di (meth) acrylate (A) is 1 to 60% by mass and the mono (meth) acrylate (B) is 40 to 99% by mass. It is a composition obtained by adding the partial polymer composition (D) obtained by superposing | polymerizing the monomer mixture containing these.

  An acrylic film according to another embodiment of the present invention is a film obtained by polymerizing the above polymerizable composition.

  The optical member by the other aspect of this invention is an optical member using said acrylic film.

  ADVANTAGE OF THE INVENTION According to this invention, the polymeric composition which can form the acrylic film excellent in workability, flexibility, transparency, and heat resistance can be provided. Moreover, according to this invention, the acrylic film excellent in workability, flexibility, transparency, and heat resistance, and the optical member using this acrylic film can be provided.

It is a schematic block diagram for demonstrating the measuring method of the side luminance of the acrylic film of the Example of this invention.

The polymerizable composition (W) according to the embodiment of the present invention has the following general formula (1):
^{_{CH 2 = CR 1 -COO-X}} -COCR 1 = CH 2 (1)
Wherein X is a divalent group having a number average molecular weight of 500 or more and containing at least one selected from repeating units of polyalkylene glycol, repeating units of polyester diol and repeating units of polycarbonate diol, and R ¹ is H or CH _{Shows 3} ]
Di (meth) acrylate (A) (hereinafter referred to as “component (A)”), mono (meth) acrylate (B) (hereinafter referred to as “component (B)”), and a glass transition temperature (Tg) of 100 It contains a thermoplastic polymer (C) (hereinafter referred to as “component (C)”) that is at least ° C. and is soluble in the mixture of component (A) and component (B), and a polymerization initiator (α).

  Polymeric composition (W) by other embodiment of this invention contains 1-60 mass% of components (A), and 40-99 mass% of components (B) to said polymeric composition (W). It is a composition obtained by adding the partial polymer composition (D) (hereinafter referred to as “component (D)”) obtained by polymerizing the monomer mixture.

  Hereinafter, these embodiments will be described in detail.

Ingredient (A)
The component (A) contained in the polymerizable composition (W) of the embodiment of the present invention is a di (meth) acrylate represented by the general formula (1). Component (A) is an acrylic film (F) made of a polymer obtained by polymerizing the polymerizable composition (W) to form a crosslinked structure including a long-chain molecular structure rich in flexibility. Used to impart flexibility.

  X in the general formula (1) is a divalent group containing at least one selected from a repeating unit of polyalkylene glycol, a repeating unit of polyester diol, and a repeating unit of polycarbonate diol. When the component (A) has such a divalent group X, the flexibility and transparency of the acrylic film (F) obtained by polymerizing the polymerizable composition (W) can be increased.

  The molecular weight (number average molecular weight) of the divalent group X is 500 or more, and when the molecular weight of the divalent group X is 500 or more, the flexibility of the acrylic film (F) can be improved. From the viewpoint of flexibility of the acrylic film (F), the molecular weight (number average molecular weight) of the divalent group X is preferably 550 or more, and more preferably 600 or more. Further, the molecular weight (number average molecular weight) of the divalent group X is preferably 10,000 or less, more preferably 3,000 or less, and even more preferably 1500 or less, from the viewpoint of the transparency of the acrylic film (F). . By setting the molecular weight of the divalent group X to 550 to 3000, a film having further excellent flexibility and transparency can be obtained, and by setting the molecular weight of the divalent group X to 600 to 1500, for light guide An acrylic film (F) excellent in flexibility and transparency sufficient as a film can be obtained.

  The form of the divalent group X may be either one type of repeating unit chain or two or more types of repeating unit chain.

  When the form of the divalent group X is a chain of two or more kinds of repeating units, the arrangement composition of the repeating units may be any of a random composition, a block composition, and an alternating composition.

As the divalent group X, a polyalkylene glycol chain ((R ² O) _n , R ² is an alkylene group, n is an integer of 2 or more), a polyester diol chain ((R ³ OOCR ⁴ COO) _p , R ³ and R ⁴ is an alkylene group, p is an integer of 2 or more, and a polycarbonate diol chain ((COOR ⁵ O) q, R ⁵ is an alkylene group, q is an integer of 2 or more).

  Examples of the polyalkylene glycol chain include a chain of polyethylene glycol having 12 or more repeating units such as dodecaethylene glycol, tridecaethylene glycol, tetradecaethylene glycol, pentadecaethylene glycol, hexadecaethylene glycol; Chains of polypropylene glycol with 9 or more repeating units such as decapropylene glycol, undecapropylene glycol, dodecapropylene glycol, tridecapropylene glycol; heptabylene glycol, octabutylene glycol, nonabutylene glycol, decabutylene glycol, undecabutylene Examples include a chain of polybutylene glycol having 7 or more repeating units such as glycol.

  Examples of the polyester diol chain include low molecular weight diols such as the above polyalkylene glycol or ethylene glycol, propylene glycol, butylene glycol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, and the like. And a chain of a condensation reaction product with a dibasic acid such as adipic acid, succinic acid, phthalic acid, hexahydrophthalic acid or terephthalic acid or an anhydride thereof.

  Examples of the polycarbonate diol chain include a chain of a condensation reaction product of the above polyalkylene glycol or the above low molecular weight diol and a carbonate ester such as dimethyl carbonate.

  A component (A) may be used individually by 1 type, and may use 2 or more types together.

  As the divalent group X, a polyalkylene glycol chain is preferable in terms of flexibility of the acrylic film (F), and among the polyalkylene glycol chains, the hydrophobicity of the acrylic film (F) is repeated. A polybutylene glycol chain having 7 or more units is more preferable, and a hepttabylene glycol chain, octabutylene glycol chain, nonabutylene glycol chain, decabutylene glycol chain, or undecabutylene glycol chain is particularly preferable.

  Specific examples of component (A) include acrylate ester PBOM (polybutylene glycol dimethacrylate, molecular weight of divalent group X = 648 (median)) manufactured by Mitsubishi Rayon Co., Ltd .; Bremer PDE manufactured by NOF Corporation -600 (polyethylene glycol dimethacrylate, molecular weight of divalent group X = 616 (median value)), Blemmer PDP-700 (polypropylene glycol dimethacrylate, molecular weight of divalent group X = 696 (median value)), Blemmer PDT-650 (Polytetramethylene glycol dimethacrylate, molecular weight of divalent group X = 648 (median value)), Bremer 40PDC-1700B (polyethylene glycol-polypropylene glycol-polyethylene glycol dimethacrylate, molecular weight of divalent group X = 1704 (median value) ), Blemmer ADE 600 (Molecular weight of polyethylene glycol diacrylate, divalent group X = 616 (median value)); NK ester A-600 (polyethylene glycol diacrylate, molecular weight of divalent group X = 616 (manufactured by Shin-Nakamura Chemical Co., Ltd.)) Median)), NK ester A-1000 (polyethylene glycol diacrylate, molecular weight of (X) = 1012 (median value)), NK ester APG-700 (polypropylene glycol diacrylate, molecular weight of divalent group X = 696 (middle) Value)), NK ester 14G (polyethylene glycol dimethacrylate, molecular weight of divalent group X = 616 (median value)) and NK ester 23G (polyethylene glycol dimethacrylate, molecular weight of divalent group X = 1012 (median value)) ( All trade names are industrially available and suitable You can use.

  In the present invention, “(meth) acrylate” means at least one selected from “acrylate” and “methacrylate”.

  The content of the component (A) (including the component (A) which is a raw material of the partial polymer composition (D) described later) is preferably 10 to 90% by mass from the viewpoint of imparting flexibility. 65 mass% is more preferable, and 20-60 mass% is especially preferable.

Ingredient (B)
The component (B) contained in the polymerizable composition (W) of the embodiment of the present invention is mono (meth) acrylate. Component (B) is used as a base component of the polymerizable composition (W).

  Examples of the component (B) include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, and n-propyl (meth) acrylate. Alkyl (meth) acrylates such as isopropyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and lauryl (meth) acrylate; aromatic methacrylates such as phenyl (meth) acrylate and benzyl (meth) acrylate; isobornyl (meth) acrylate , Methylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, 1-adamantyl (meth) acrylate, 2-methyl-2-adamantyl (meth) acrylate, 2-ethyl-2-adamanti Include alicyclic methacrylate (meth) acrylate. These may be used alone or in combination of two or more. Among these, alkyl (meth) acrylate is preferable from the viewpoint of transparency of the acrylic film (F), alkyl (meth) acrylate having 1 to 8 carbon atoms in the alkyl group is more preferable, and methyl methacrylate is particularly preferable.

  The content of the component (B) (including the constituent unit derived from the component (B) in the thermoplastic polymer (C) described later and the component (B) which is a raw material of the partial polymer composition (D)) is flexible. From the point which provides property, 10-90 mass% is preferable in polymeric resin composition (W), 35-85 mass% is more preferable, and 40-80 mass% is further more preferable.

Ingredient (C)
The component (C) contained in the polymerizable composition (W) of the embodiment of the present invention has a glass transition temperature (Tg) of 100 ° C. or higher and is soluble in a mixture of the component (A) and the component (B). A thermoplastic polymer. When the polymerizable composition (W) further contains the component (D), it is a thermoplastic polymer that is soluble in the mixture of the component (A), the component (B), and the component (D). A component (C) is used in order to improve the heat resistance of the acrylic film (F) obtained by superposing | polymerizing polymeric composition (W).

  The glass transition temperature (Tg) in the present invention was obtained by measuring using a dynamic viscoelasticity measuring device under measurement conditions of a frequency of 1 Hz, a temperature range of 30 to 150 ° C., and a heating rate of 2 ° C./min. , The temperature at which the maximum value of the temperature-tan δ curve is shown.

  Examples of the component (C) include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) And poly (meth) acrylates obtained by polymerizing (meth) acrylates such as acrylate and t-butylcyclohexyl (meth) acrylate in combination of one or more. From the viewpoints of transparency and solubility, an alkyl (meth) acrylate polymer is preferable, an alkyl (meth) acrylate polymer having 1 to 8 carbon atoms in the alkyl group is more preferable, and polymethyl methacrylate is particularly preferable.

  As the other thermoplastic polymer, a necessary amount can be added as long as it can be dissolved in the mixture of the component (A) and the component (B). When the polymerizable composition (W) further contains the component (D), the necessary amount of the usual thermoplastic polymer is added as long as it can be dissolved in the mixture of the component (A), the component (B), and the component (D). it can.

  When a thermoplastic polymer that does not dissolve in the mixture of component (A) and component (B) (or a mixture containing component (D)) is used, in the film obtained by polymerizing the polymerizable composition (W) A macroscopic phase separation structure is formed, and the transparency tends to decrease and the flexibility tends to decrease.

  The glass transition temperature (Tg) of the component (C) needs to be 100 ° C. or higher from the viewpoint of improving heat resistance, and is preferably 300 ° C. or lower from the viewpoint of workability, solubility, etc., and 250 ° C. The following is more preferable.

  The mass average molecular weight (Mw) of the component (C) is preferably 5000 or more, more preferably 10,000 or more from the viewpoint of obtaining appropriate flexibility. Further, from the viewpoint of obtaining good workability without increasing the viscosity and solubility, the mass average molecular weight (Mw) of the component (C) is preferably 500,000 or less, more preferably 400,000 or less.

  The content of the component (C) is preferably 1% by mass or more, more preferably 3% by mass or more, and further preferably 5% by mass or more in the polymerizable resin composition (W) from the viewpoint of improving heat resistance. In view of optimization of viscosity and suppression of phase separation, the content of component (C) is preferably 50% by mass or less, more preferably 45% by mass or less, and more preferably 40% by mass in the polymerizable resin composition (W). The following is more preferable.

Polymerization initiator (α)
In the polymerizable composition (W) of the embodiment of the present invention, a polymerization initiator (α) is contained in order to polymerize the polymerizable component in the polymerizable composition (W).

  Examples of the polymerization initiator (α) include a thermal polymerization initiator or a photopolymerization initiator used in thermal polymerization or active energy ray polymerization.

  Examples of the thermal polymerization initiator include benzoyl peroxide, lauroyl peroxide, t-butylperoxyisobutyrate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyneodecanoate, t -Organic peroxide polymerization initiators such as hexyl peroxypivalate, diisopropyl peroxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate; 2,2'-azobisisobutyronitrile, 2 Azo polymerization initiators such as 2,2′-azobis (2,4-dimethylvaleronitrile) and 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile). These may be used alone or in combination of two or more.

  Examples of the photopolymerization initiator include 1-hydroxy-cyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, methylphenylglyoxylate, acetophenone, benzophenone, diethoxyacetophenone, 2, 2-dimethoxy-2-phenylacetophenone, 1-phenyl-1,2-propane-dione-2- (o-ethoxycarbonyl) oxime, 2-methyl [4- (methylthio) phenyl] -2-morpholino-1-propanone , Benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-chlorothioxanthone, isopropylthioxanthone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide , Diphenylphosphine oxide, 2-methyl-benzoyl diphenyl phosphine oxide, benzoyl dimethoxy phosphine oxide. These may be used alone or in combination of two or more.

  As a content of the polymerization initiator (α) in the polymerizable composition (W), the polymerizable composition (W) before adding the polymerization initiator (α) from the point of setting the polymerization time to an appropriate range. 0.005 parts by mass or more with respect to 100 parts by mass (the total amount of component (A), component (B), and component (C), and the total amount including component (D) when component (D) is included) Preferably, 0.01 parts by mass or more is more preferable, 0.05 parts by mass or more is more preferable, and from the viewpoint of suppressing coloring, 5 parts by mass or less is preferable, and 1 part by mass or less is more preferable. More preferred is less than or equal to parts by weight.

  When polymerizing the polymerizable composition (W), thermal polymerization and active energy ray polymerization can be used in combination as necessary.

Polymerizable composition (W)
The polymerizable composition (W) contains a component (A), a component (B), a component (C), and a polymerization initiator (α), and further a partial polymer composition (D) (component (D)). May be contained.

  In the polymerizable composition (W), vinyl monomers other than the component (A) and the component (B) can be included as necessary. The content of the other vinyl monomer is preferably 10% by mass or less from the viewpoint of the transparency of the polymerizable composition (W).

  Examples of other vinyl monomers include aromatic vinyl monomers such as styrene and α-methylstyrene; monovinyl monomers such as nitrile group-containing vinyl monomers such as acrylonitrile and methacrylonitrile. Moreover, polyvinyl monomers, such as ethylene glycol di (meth) acrylate other than a component (A), are mentioned. These may be used alone or in combination of two or more.

  The viscosity of the polymerizable composition (W) is preferably 100 mPa · s or more from the viewpoint of production of the acrylic film (F). In particular, after forming a continuous coating film of the polymerizable composition (W) on the continuous base film, the coating film of the polymerizable composition (W) is polymerized by continuously heating or irradiating active energy rays, When the acrylic film (F) is continuously produced, a film having excellent thickness accuracy is obtained. On the other hand, from the viewpoint of transparency of the acrylic film (F), the viscosity of the polymerizable composition (W) is preferably 100,000 mPa · s or less. If it exists in the range of such a viscosity, the compatibility of the component of polymeric composition (W) will become higher, and the film which was excellent in transparency can be manufactured. In the present specification, the viscosity is a value measured at 25 ° C.

  A release agent can be blended in the polymerizable composition (W) according to the embodiment of the present invention as necessary.

  As a compounding quantity of a mold release agent, from the point which makes peelability favorable, polymerizable composition (W) 100 mass parts (component (A) and component before adding a mold release agent and a polymerization initiator ((alpha))) 0.001 mass part or more is preferable with respect to the total amount of (B) and component (C), and when component (D) is contained, the total amount including component (D) is more preferably 0.005 mass parts or more. On the other hand, 0.5 mass part or less is preferable from the point which maintains the water absorption and surface state of an acrylic film (F) favorably. In particular, the releasability when peeling from a sheet-like material such as a polyethylene terephthalate (PET) film or a stainless steel plate as a mold can be improved.

  Examples of such a release agent include sodium dioctyl sulfosuccinate (trade name: Aerosol OT-100) manufactured by Nippon Cytec Industries, Ltd., diethyl ester phosphate monoethyl phosphate and monoethyl phosphate manufactured by Johoku Chemical Industry Co., Ltd. And a 55:45 mixture of esters (trade name: JP-502).

  The polymerizable composition (W) according to the embodiment of the present invention includes a lubricant, a plasticizer, an antibacterial agent, an antifungal agent, a light stabilizer, an ultraviolet absorber, a bluing agent, a dye, and an antistatic agent as necessary. Various additives such as a heat stabilizer can be added.

  The polymerizable composition (W) according to the embodiment of the present invention can be polymerized by at least one method selected from a thermal polymerization method and an active energy ray polymerization method to obtain an acrylic film suitable as an optical member. it can.

Partial polymer composition (D) (component (D))
The polymerizable composition (W) according to the embodiment of the present invention can contain the partial polymer composition (D) as necessary.

  This partial polymer composition (D) is a syrup obtained by polymerizing a part of the monomer mixture (AB) containing the component (A) and the component (B), and the component (A) and A copolymer of the component (A) and the component (B), which is a partial polymer of the monomer mixture (AB), is dissolved in the mixture of the component (B).

  Content of the component (A) in this monomer mixture (AB) is 1-60 mass%, and 5-30 mass% is preferable. When the content of the component (A) is 1% by mass or more, the compatibility between the partial polymer composition (D) and the component (A) becomes good, and an acrylic film (F) with good transparency is obtained. be able to. Moreover, when the content of the component (A) is 60% by mass or less, the fluidity of the partial polymer composition (D) can be prevented from being lost even when the partially crosslinked gel-like polymer is produced.

  Moreover, content of the component (B) in this monomer mixture (AB) is 40-99 mass%, and 70-95 mass% is preferable. When the content of the component (B) is 99% by mass or less, the compatibility between the partial polymer composition (D) and the component (A) becomes good, and an acrylic film (F) with good transparency is obtained. be able to. Moreover, when the content of the component (B) is 40% by mass or more, the production of the partially crosslinked gel polymer of the partial polymer composition (D) is suppressed, and the fluidity is not lost. it can.

  The viscosity of the partial polymer composition (D) is preferably 100 to 5,000 mPa · s.

  An acrylic having excellent thickness accuracy using a polymerizable composition (W) containing such a partial polymer composition (D) by setting the viscosity of the partial polymer composition (D) to 100 mPa · s or more. It becomes easy to produce the film (F) continuously. For example, a continuous coating film of the polymerizable composition (W) is formed on a continuous sheet-like material, and the continuous coating film of the polymerizable composition (W) is polymerized by continuously heating or irradiating active energy rays. Thus, when the acrylic film (F) is produced, a film having excellent thickness accuracy is obtained. Moreover, the production | generation of the partial crosslinked gel-like polymer of a partial polymer composition (D) is suppressed by making the viscosity of a partial polymer composition (D) 5,000 mPa * s or less, and transparency is higher. A film can be produced.

  The content of the partial polymer of the monomer mixture (AB) in the partial polymer composition (D) is preferably 5 to 50% by mass, and more preferably 10 to 40% by mass. By setting the content of the partial polymer to 5% by mass or more, the viscosity of the partial polymer composition (D) can be set to an appropriate level, while the content of the partial polymer is set to 50% by mass or less. By doing, production | generation of a partially crosslinked gel-like polymer is suppressed and an acrylic film (F) with higher transparency can be manufactured.

  The content of component (D) is preferably 99% by mass or less, more preferably 97% by mass or less, and still more preferably 95% by mass or less in the polymerizable resin composition (W) from the viewpoint of improving heat resistance. In view of optimization of viscosity and suppression of phase separation, the content of component (D) is preferably 30% by mass or more, more preferably 40% by mass or more, and 45% by mass in the polymerizable resin composition (W). The above is more preferable.

  5-50 mass% is preferable in a polymer composition (W), and, as for the ratio of the sum total of a component (C) and a partial polymer, 10-30 mass% is more preferable.

  As a polymerization initiator used for the polymerization of the monomer mixture (AB) for obtaining the partial polymer composition (D), a polymerization initiator (α used also for the polymerization of the polymerizable composition (W)) ) And the like.

  As an addition amount of the polymerization initiator with respect to the monomer mixture (AB), 0.001 to 5 parts by mass is preferable with respect to 100 parts by mass of the monomer mixture (AB), and 0.005 to 0.1 parts by mass is preferable. More preferred is 0.01 to 0.03 parts by mass.

  When obtaining the partial polymer composition (D), a chain transfer agent can be added to the monomer mixture (AB) as needed for the purpose of preventing the formation of a partially crosslinked gel-like polymer.

  Examples of the chain transfer agent include alkyl mercaptans such as n-butyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan, α-methylstyrene dimer, and the like.

  The addition amount of the chain transfer agent with respect to the monomer mixture (AB) is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the monomer mixture (AB). 0.2 to 0.5 parts by mass is particularly preferable. When the addition amount of the chain transfer agent is 0.01 parts by mass or more, gelation of the partial polymer composition (D) tends to be suppressed. On the other hand, when the addition amount of the chain transfer agent is 10 parts by mass or less, the partial polymerization composition The viscosity of (D) tends to be at an appropriate level.

  A polymerization inhibitor can be added to the monomer mixture (AB) as necessary to avoid coloring or spontaneous curing of the partially polymerized composition (D).

  Examples of the polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, 2,6-di-t-butyl-4-methylphenol, and 2,4-dimethyl-6-t-butylphenol. These may be used alone or in combination of two or more.

  As a method for producing the partial polymer composition (D), for example, the monomer mixture (AB) is charged into a reactor equipped with a cooling pipe, a thermometer and a stirrer, and heating is started while stirring to a predetermined temperature. The polymerization initiator is added at the time, and the temperature in the reactor is kept constant for a predetermined time, and then rapidly cooled to near room temperature by cooling under reduced pressure or the like to stop the polymerization.

Acrylic film (F)
The acrylic film (F) according to the embodiment of the present invention can be produced, for example, as in the following (1) or (2).

  (1) Prepare a mold according to the application, inject the present polymerizable composition containing a polymerization initiator through a gasket, etc., and polymerize by irradiation with active energy rays or heat treatment from one or both sides of the mold. The composition is cured.

  (2) A continuous coating film of the polymerizable composition (W) is formed on the continuous sheet-like material, and the coating film of the polymerizable composition (W) is continuously polymerized by heating or irradiation with active energy rays, and then The acrylic film which is a polymer of the coating film of the obtained polymerizable composition (W) is peeled from the sheet-like material.

  The acrylic film (F) according to the embodiment of the present invention is excellent in processability, flexibility, transparency and heat resistance.

  As this acrylic film (F), when a tensile test was conducted at 23 ° C. and 500 mm / min using a dumbbell-shaped No. 1 test piece in accordance with JIS K6251, the elongation at the time of cutting the film was 7%. The above is preferable.

  As this acrylic film (F) has the outstanding characteristic as above-mentioned, it can be used conveniently as an optical member.

  The evaluation of the luminance of the acrylic film (F) can be performed, for example, in a state as shown in FIG. The light emitted from the light source 3 is incident from the end surface (A) (reference numeral 4 in the drawing) of the acrylic film (F) 1 whose both surfaces are covered with the reflection sheet 2, passes through the film, and passes through the end surface ( B) It is emitted from (5 in the figure). When measuring the brightness of the acrylic film (F), the distance from the end face (b) to the end face (b) is 5 cm when the length of the light guide plate used in a small display such as a mobile phone is assumed. The above is preferable. Further, when it is assumed to be used for a display such as a medium-sized portable game machine, 10 cm or more is more preferable. When the distance from the end face (b) to the end face (b) is 10 cm or more, a slight difference in transmission loss due to light absorption, scattering, reflection, etc. tends to be observed as a large luminance difference. A film capable of obtaining high brightness even when the distance from the end face (b) to the end face (b) is long is suitable as an optical member because of its high transparency, and particularly suitable for light guide plate applications that require transparency in a long optical path. is there.

  As thickness of this acrylic film (F), 5 micrometers-500 micrometers are preferable, 10-500 micrometers is more preferable, 25-400 micrometers is more preferable. By setting the thickness of this film to 5 μm to 500 μm, it can be suitably used for optical members, particularly for thin light guide plate applications.

  The active energy rays used when the polymerizable composition (W) is polymerized by irradiation with active energy rays include visible light, ultraviolet rays, infrared rays, X rays, α rays, β rays, electron rays, γ rays and the like. Among them, visible light and ultraviolet light are particularly preferable.

  When manufacturing this acrylic film (F) continuously, this acrylic film (F) can be collect | recovered in the state wound around rolls, such as a paper tube and a plastic core.

Optical member Examples of the optical member according to the embodiment of the present invention include an optical lens such as a Fresnel lens; a polarizing film, a polarizer protective film, a retardation film, a light diffusion film, a viewing angle widening film, a reflective film, an antireflection film, Optical films such as anti-glare films and brightness enhancement films; prism sheets; microlens arrays; conductive films such as conductive films for touch panels; reflective materials used for road signs and the like; films for solar cells; Contrast-enhancement film; thin liquid crystal display, flat panel display, plasma display, mobile phone display, mobile phone keypad illumination, personal computer keyboard illumination, side light type light guide plate used for billboards and the like.

  Hereinafter, the present invention will be specifically described with reference to examples. In the following description, “part” means “part by mass”.

  Evaluation of the acrylic film of a present Example was implemented with the following method.

(1) Glass transition temperature (Tg)
A test piece of dumbbell-shaped No. 1 acrylic film was prepared using a super dumbbell cutter (trade name: SDK-100D, manufactured by Dumbbell Co., Ltd.), and both ends were cut. About the obtained test piece, using a dynamic viscoelasticity measuring device (trade name: EXSTAR DMS6100, manufactured by SII Nano Technology Co., Ltd.), a frequency of 1 Hz, a temperature range of 30 to 150 ° C, and a heating rate of 2 ° C. The glass transition temperature (Tg) was defined as the temperature at which the maximum value of the obtained temperature-tan δ curve was measured.

(2) Transfer shape stability An A4 size acrylic film is sandwiched between a PET film and a transfer mold member to which a prism shape having a pitch of 30 μm and a height of 30 μm is continuously formed. Name: Pressed at a temperature of 120 ° C. and a press pressure of 1 MPa using a hydraulic molding machine (manufactured by Shoji Tekko Co., Ltd.) to give a fine prism shape on one side of the acrylic film. Next, this acrylic film was stored in a high temperature tester at a temperature of 80 ° C. for 24 hours. Then, the height difference of the prism shape before and after storage is measured using a laser microscope (trade name: VK-8510, manufactured by Keyence Corporation), and the ratio of the height difference after heating and storage is defined with the initial height difference as 100. The stability of the transferred prism shape was evaluated.

(3) Elastic modulus Based on JIS K6251, five test pieces of dumbbell-shaped No. 1 acrylic film were prepared using a super dumbbell cutter (trade name: SDK-100D, manufactured by Dumbbell Co., Ltd.). The obtained test piece was subjected to five tensile tests using a tensile tester (trade name: Strograph T, manufactured by Toyo Seiki Seisakusho Co., Ltd.) at a room temperature of 23 ° C. and a tensile speed of 500 mm / min. The average value of the tangent lines of the stress strain curve was obtained and used as the elastic modulus.

(4) Elongation at the time of cutting In accordance with JIS K6251, five test pieces of dumbbell-shaped type 1 acrylic film were prepared using a super dumbbell cutter (trade name: SDK-100D, manufactured by Dumbbell Co., Ltd.). . Using the tensile tester (trade name: Strograph T, manufactured by Toyo Seiki Seisakusho Co., Ltd.), the obtained test piece was subjected to a tensile test 5 times at a room temperature of 23 ° C. and a tensile speed of 500 mm / min. Time elongation was determined as an average value.

(5) Total light transmittance The total light transmittance was measured using a haze meter (trade name: NDH2000, manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K7361-1, an acrylic film cut into a 5 cm square. did.

(6) Haze value The haze value was measured using a haze meter (trade name: NDH2000, manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K7105.

(7) YI value The YI value was measured using a spectroscopic color difference meter (trade name: SE-2000, manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K7105.

(8) Side luminance A rectangular acrylic film 1 having a length of 200 mm and a width of 100 mm, an LED pack light source 3 for a notebook personal computer liquid crystal panel (trade name: LTN141AT05, manufactured by Samsung), and a reflective sheet 2 having a film thickness of 50 μm (trade name: The side luminance of the acrylic film was measured in a state where a Ruir mirror (made by Reiko Co., Ltd.) was installed as shown in FIG.

  In this installed state, the distance from the end face (A) (reference numeral 4 in the figure) to the end face (B) (reference numeral 5 in the figure) of the acrylic film is 200 mm. Moreover, as an acrylic film, the end surface (I) and the surface of the end surface (B) are rotated using an end surface processing apparatus (trade name: PB-500, manufactured by Megaro Technica Co., Ltd.) at a feed rate of 17.5 mm / sec. What used the end surface process at the speed of 4000 rpm was used.

  When measuring the side luminance, a luminance meter (trade name: CS-100A, manufactured by Konica Minolta Sensing Co., Ltd.) is installed at a position 1 m from the end surface (b), and the light incident from the end surface (b) The side luminance when emitted from (b) was measured.

(9) Viscosity Using a B-type viscometer (manufactured by Tokyo Keiki Co., Ltd.), the viscosity of the partial polymer composition (D) at 25 ° C. was measured.

[Example 1]
60 parts of methyl methacrylate (B-1) (trade name: Acryester M, manufactured by Mitsubishi Rayon Co., Ltd.) as mono (meth) acrylate (B), and polymethyl methacrylate (C-1) as thermoplastic polymer (C) (Product name: BR-83, manufactured by Mitsubishi Rayon Co., Ltd., methyl methacrylate = 100, Mw = about 40000, Tg = 119.7 ° C.) and 10 parts.

  Then, polybutylene glycol dimethacrylate (A-1) (trade name: Acryester PBOM, manufactured by Mitsubishi Rayon Co., Ltd.) as di (meth) acrylate (A) represented by the general formula (1). 30 parts of molecular weight of valent group X = 648 (median value), 1-hydroxy-cyclohexyl-phenyl-ketone (α-1) as a polymerization initiator (α) (trade name: Irgacure 184, manufactured by Ciba Japan Co., Ltd.) ) 0.3 part and 0.05 part of sodium dioctylsulfosuccinate (trade name: Aerosol OT-100, manufactured by Nippon Cytec Industries Co., Ltd.) as a release agent, mixed, and then degassed under reduced pressure And a polymerizable composition (W-1) was obtained.

A glass plate having a length of 300 mm and a width of 300 mm was made to face each other at intervals of 0.4 mm through a polyvinyl chloride gasket, and the polymerizable composition (W-1) was injected into the formed mold. Next, the mold was irradiated with light at a peak illuminance of 2.1 mW / cm ² for 45 minutes using a chemical lamp (trade name: FL20SBL, manufactured by Toshiba Lighting & Technology Co., Ltd.), and polymerizable composition (W-1). Next, the polymerization was completed by heating in an air oven at 130 ° C. for 15 minutes. Thereafter, the mold was cooled to room temperature, the mold was removed, and an acrylic film (a) having an average thickness of about 400 μm was obtained.

  Table 1 shows the content (parts by mass) of each component of the polymerizable composition (W). In Table 1, the total amount of PBOM indicates the total amount of polybutylene glycol dimethacrylate (A-1) used until the polymerizable composition (W) is obtained. The evaluation results are shown in Table 2.

[Example 2]
In a reactor equipped with a condenser, a thermometer and a stirrer, 10 parts of polybutylene glycol dimethacrylate (A-1), 90 parts of methyl methacrylate (B-1), and n-octyl mercaptan (trade name: NOM, Elf Atchem Japan Co., Ltd. (0.4 part) was charged, and heating was started while stirring. When the temperature in the reactor reaches 70 ° C., 2,2′-azobis (2,4-dimethylvaleronitrile) (α-2) (trade name: V-65, Wako Pure) as the polymerization initiator (α) 0.026 part of Yakuhin Kogyo Co., Ltd.) was added. Next, after the temperature in the reactor reached 80 ° C., the reactor was held for 60 minutes and quenched to 40 ° C. with a large amount of water and reduced-pressure cooling to obtain a partial polymer composition (D-1). The viscosity at 25 ° C. of the partial polymer composition (D-1) was 167 mPa · s, and the content of the partial polymer in the partial polymer composition (D-1) was 15.7% by mass. .

  Next, 46.1 parts of the obtained partial polymer composition (D-1) was added to a mixture obtained by mixing 18.5 parts of methyl methacrylate (B-1) and 10 parts of polymethyl methacrylate (C-1). (Inside, 7.2 parts of partial polymer) and 25.3 parts of polybutylene glycol dimethacrylate (A-1) were added and mixed to obtain a syrup composition. To 100 parts of this syrup composition, 0.3 part of 1-hydroxy-cyclohexyl-ketone (α-1) and 0.05 part of sodium dioctylsulfosuccinate (trade name: Aerosol OT-100) were added and mixed. Thereafter, deaeration treatment was performed under reduced pressure to obtain a polymerizable composition (W-2).

A glass plate having a length of 300 mm and a width of 300 mm was made to face each other at intervals of 0.4 mm through a polyvinyl chloride gasket, and the polymerizable composition (W-2) was poured into the formed mold. Next, the mold was irradiated with light at a peak illuminance of 2.1 mW / cm ² for 45 minutes using a chemical lamp (trade name: FL20SBL, manufactured by Toshiba Lighting & Technology Co., Ltd.), and polymerizable composition (W-2). Next, the polymerization was completed by heating in an air oven at 130 ° C. for 15 minutes. Thereafter, the mold was cooled to room temperature, the mold was removed, and an acrylic film (b) having an average thickness of about 400 μm was obtained.

  Table 1 shows the content (parts by mass) of each component of the polymerizable composition (W). The evaluation results are shown in Table 2.

[Comparative Example 1]
A polymerizable composition (W) was prepared in the same manner as in Example 1 except that the blending amounts of polybutylene glycol dimethacrylate (A-1) and methyl methacrylate (B-1) were as shown in Table 1. An acrylic film (c) was obtained using this polymerizable composition (W). The evaluation results are shown in Table 2.

  In Comparative Example 1, since the polymerizable composition (W) did not contain the polymethyl methacrylate (C-1) as the thermoplastic polymer (C), the transfer shape stability, which is an index of heat resistance, was poor.

[Comparative Example 2]
The polymerizable composition (W) was prepared in the same manner as in Example 2 except that the blending amounts of the polybutylene glycol dimethacrylate (A-1) and the partial polymer composition (D-1) were as shown in Table 1. The acrylic film (d) was obtained using this polymerizable composition (W). The evaluation results are shown in Table 2.

  In Comparative Example 2, since the polymerizable composition (W) did not contain the polymethyl methacrylate (C-1) as the thermoplastic polymer (C), the transfer shape stability, which is an index of heat resistance, was poor.

1: Acrylic film 2: Reflective sheet 3: Light source 4: End face (A)
5: End face (b)

Claims (10)

The following general formula (1):
_{^{CH 2 = CR 1 -COO-X}} -COCR 1 = CH 2 (1)
[Wherein X is a divalent group containing a repeating unit of polyalkylene glycol having a number average molecular weight of 500 or more, and R ¹ represents H or CH ₃ ]
Di (meth) acrylate (A) represented by:
Mono (meth) acrylate (B);
A thermoplastic polymer (C) having a glass transition temperature (Tg) of 100 ° C. or higher and soluble in a mixture of the di (meth) acrylate (A) and the mono (meth) acrylate (B);
A polymerizable composition containing a polymerization initiator (α),
It is obtained by polymerizing a monomer mixture containing 1 to 60% by mass of the di (meth) acrylate (A) and 40 to 99% by mass of the mono (meth) acrylate (B) to the polymerizable composition. Obtained by adding the partial polymer composition (D),
The polymerizable composition in which the divalent group X in the general formula (1) is a polyalkylene glycol chain.   The polymerizable composition according to claim 1, wherein the divalent group X in the general formula (1) has a number average molecular weight of 600 or more and 10,000 or less.   The polyalkylene glycol chain is a polyethylene glycol chain having 12 or more repeating units, a polypropylene glycol chain having 9 or more repeating units, or a polybutylene glycol chain having 7 or more repeating units. Polymerizable composition.   The polymerizable composition according to any one of claims 1 to 3, wherein the polyalkylene glycol chain is a polybutylene glycol chain.   The polymerizable composition according to claim 4, wherein the polyalkylene glycol chain is a polybutylene glycol chain having 7 or more repeating units.   The content of the copolymer of the di (meth) acrylate (A) and the mono (meth) acrylate (B) in the partial polymer composition (D) is 5 to 50% by mass, and the part The polymerizable composition according to any one of claims 1 to 5, wherein the viscosity of the polymer composition (D) measured at 25 ° C is in the range of 100 to 5,000 mPa · s.   The said mono (meth) acrylate (B) is an alkyl (meth) acrylate, The said thermoplastic polymer (C) is a polyalkyl (meth) acrylate, The polymeric property as described in any one of Claims 1-6. Composition.   The polymerizable composition according to claim 1, wherein the polymerization initiator (α) is a photopolymerization initiator. It is an acrylic film obtained by superposing | polymerizing the polymeric composition of Claim 7, Comprising : The said polymerization initiator ((alpha)) is an acrylic film which is a photoinitiator .   An optical member using the acrylic film according to claim 9.

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