JP4802820B2 - Polymer laminate, retardation film, and method for producing polymer laminate - Google Patents

Description

  The present invention relates to a polymer laminate suitably used for a liquid crystal display device and the like, and more particularly to a polymer laminate using a transparent substrate made of a cycloolefin resin.

  The liquid crystal display device has features such as power saving, light weight, thinness, and the like, and has rapidly spread in recent years in place of the conventional CRT display. As a general liquid crystal display device, as shown in FIG. 4, a liquid crystal display device having an incident side polarizing plate 102 </ b> A, an outgoing side polarizing plate 102 </ b> B, and a liquid crystal cell 104 can be exemplified. The polarizing plates 102A and 102B are configured to selectively transmit only linearly polarized light (schematically illustrated by arrows in the figure) having a vibration surface in a predetermined vibration direction. They are arranged to face each other in a crossed Nicol state so as to have a right angle relationship with each other. The liquid crystal cell 104 includes a large number of cells corresponding to the pixels, and is disposed between the polarizing plates 102A and 102B.

In addition, the liquid crystal display device has a viewing angle problem that the contrast, color, and the like change when viewed from the front and when viewed from an oblique direction. A retardation film having a predetermined birefringence is used between the plates.
More recently, AG films (anti-glare films), AR films (anti-reflection films), etc. have been used on the forefront of liquid crystal display devices in order to prevent the visibility of images from being deteriorated by external light. Yes.

  As described above, a plurality of optical function films such as a polarizing plate, a retardation film, and an AG / AR film are used in the liquid crystal display device. Conventionally, as a transparent substrate constituting such an optical function film, cellulose triacetate is used. The resulting film has been widely used. Cellulose triacetate is a material with low birefringence and excellent optical isotropy, so it is easy to design optical properties, and because it uses cellulose, which is a natural material, as a raw material, it is industrially inexpensive. Since it is highly useful in that it can be obtained in the above, it has been suitably used for the optical functional film.

  However, the optical functional film used for the liquid crystal display device as described above is required to have a desired birefringence according to the display method of various liquid crystal display devices, and the cellulose triacetate has heat resistance. There is a problem that it is low and has high water absorption, so that it is easily deformed by heat and moisture.

For such problems, Patent Documents 1 and 2 disclose an optical functional film using a cycloolefin resin instead of the cellulose triacetate. The cycloolefin resin is an advantage that the cycloolefin resin can control the glass transition point and the moisture absorption rate within a preferable range by molecular design, and can realize good heat resistance and appropriate water absorption. Have For this reason, by using a cycloolefin-based resin, for example, by designing the molecule so that the saturated water absorption at 23 ° C. is 1% by weight or less, an optical functional film with little optical property change and dimensional change due to water absorption is obtained. It is possible.
However, the optical functional film used in the liquid crystal display device or the like usually has a structure in which an optical functional layer that expresses a desired optical function is laminated on a transparent substrate. In general, the material used for the optical functional layer has a problem of poor adhesion. For this reason, the cycloolefin-based resin has the advantage of being excellent in water resistance as described above, but has a problem that it lacks practicality.

Japanese Patent Laying-Open No. 2005-8698 Japanese Patent Application Laid-Open No. 2004-309979

  The present invention has been made in view of such problems, and a main object of the present invention is to provide a polymer laminate that uses a transparent substrate made of a cycloolefin-based resin and has excellent adhesion. It is.

  In order to solve the above-described problems, the present invention provides a polymer laminate having a transparent substrate made of a cycloolefin resin and an adhesion functional layer formed on and in contact with the transparent substrate and containing a polymer of a polymerizable monomer. The polymerizable monomer has at least one polymerizable functional group selected from the group consisting of the following formulas (I), (II), (III), (IV) and (V). And the value (N / M) obtained by dividing the number N of carbon atoms constituting the polymerizable monomer by the number M of elements other than carbon and hydrogen constituting the polymerizable monomer is 3 or more. A polymer laminate is provided.

According to the present invention, the adhesion between the transparent substrate made of the cycloolefin resin and the adhesion functional layer is improved by containing a polymer of the polymerizable monomer having the structure in the adhesion functional layer. be able to.
Therefore, according to the present invention, it is possible to provide a polymer laminate that uses a transparent substrate made of a cycloolefin-based resin and has excellent adhesion.
In the above formulas (I), (II), (III), (IV) and (V), R ¹ , R ² and R ³ represent a methyl group or hydrogen. R ⁴ represents hydrogen, a methyl group or an ethyl group.

  The present invention also provides a retardation film, wherein a retardation layer containing a liquid crystal material is formed on the adhesion functional layer of the polymer laminate of the present invention.

  According to the present invention, by using the polymer laminate of the present invention in which a transparent substrate made of a cycloolefin resin is used, excellent adhesion between the adhesion functional layer and the transparent substrate is achieved. And the retardation film excellent in the temporal stability of the optical property can be obtained.

  Furthermore, the present invention uses a transparent substrate made of a cycloolefin-based resin, and after forming the adhesion functional layer forming layer by applying a coating liquid for forming an adhesion functional layer containing a polymerizable monomer on the transparent substrate. , A method for producing a polymer laminate having an adhesion functional layer forming step of polymerizing the polymerizable monomer to form an adhesion functional layer, wherein the polymerizable monomer is represented by the following formulas (I), (II), It has at least one polymerizable functional group selected from the group consisting of (III), (IV) and (V), and the number of carbon atoms N constituting the polymerizable monomer is changed to the polymerizable monomer. The value (N / M) divided by the number M of elements other than carbon and hydrogen constituting the polymer is 3 or more.

According to the present invention, the adhesion functional layer is formed on the transparent substrate made of the cycloolefin resin by using the adhesion functional layer forming coating liquid containing the polymerizable monomer having the structure in the adhesion functional layer forming step. By being formed, an adhesion functional layer having excellent adhesion to the transparent substrate can be formed.
Therefore, according to the present invention, a transparent substrate made of a cycloolefin resin is used, and a polymer laminate having excellent adhesion can be produced.
In the above formulas (I), (II), (III), (IV) and (V), R ¹ , R ² and R ³ represent a methyl group or hydrogen. R ⁴ represents hydrogen, a methyl group or an ethyl group.

  The present invention produces an effect that a transparent substrate made of a cycloolefin-based resin is used and a polymer laminate having excellent adhesion can be provided.

  Hereinafter, the polymer laminate, the retardation film, and the method for producing the polymer laminate of the present invention will be described in detail.

A. Polymer laminate First, the polymer laminate of the present invention will be described. The polymer laminate of the present invention has a transparent substrate made of a cycloolefin-based resin and an adhesion functional layer formed so as to be in contact with the transparent substrate and containing a polymer of a polymerizable monomer, The polymerizable monomer has at least one polymerizable functional group selected from the group consisting of the above formulas (I), (II), (III), (IV), and (V), and A value (N / M) obtained by dividing the number N of carbon atoms constituting the polymerizable monomer by the number M of elements other than carbon and hydrogen constituting the polymerizable monomer (hereinafter sometimes simply referred to as “carbon content ratio”). ) Is 3 or more.

Such a polymer laminate of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view showing an example of the polymer laminate of the present invention. As illustrated in FIG. 1, the polymer laminate 10 of the present invention has a configuration in which an adhesion functional layer 2 is formed on a transparent substrate 1 made of a cycloolefin resin.
In such an example, the polymer laminate 10 of the present invention is selected from the group consisting of the above formulas (I), (II), (III), (IV), and (V) for the adhesion functional layer 2. And a polymer of a polymerizable monomer having a carbon content ratio of 3 or more.

According to the present invention, the adhesion between the transparent substrate made of the cycloolefin resin and the adhesion functional layer is improved by containing a polymer of the polymerizable monomer having the structure in the adhesion functional layer. be able to.
In the present invention, the adhesion between the transparent substrate and the adhesion functional layer can be improved by containing a polymer of the polymerizable monomer having the structure in the adhesion functional layer based on the following reason. it is conceivable that.
In other words, conventionally, cycloolefin resins have a problem of poor adhesion to materials generally used for optical functional layers. This is because cycloolefin resins are widely used for transparent substrates for optical functional films. It is thought that the main cause was that the polarity of the molecule was lower than that of cellulose triacetate.
In this regard, in the present invention, the polymerizable monomer constituting the polymerized polymerizable monomer contained in the adhesion functional layer is represented by the above formulas (I), (II), (III), (IV) and (V ) Having at least one polymerizable functional group selected from the group consisting of, and having the carbon content ratio of the polymerizable monomer of 3 or more, the polarity of the polymerizable monomer is changed to the cycloolefin. It is considered that the adhesion between the adhesion functional layer and the transparent substrate can be improved because the polarity can be approximated to the polarity of the resin.
Therefore, according to the present invention, it is possible to provide a polymer laminate that uses a transparent substrate made of a cycloolefin-based resin and has excellent adhesion.

  The polymer laminate of the present invention has the transparent substrate and the adhesion functional layer, and may have other layers depending on the use of the polymer laminate of the present invention. is there. Hereinafter, each configuration of the polymer laminate of the present invention will be described in detail.

1. First, the adhesion functional layer in the present invention will be described. The adhesion functional layer used in the present invention has a polymerizable property having at least one polymerizable functional group selected from the group consisting of the above formulas (I), (II), (III), (IV) and (V). A polymer of the monomer is contained, and the carbon content ratio of the polymerizable monomer is 3 or more. This invention can provide the polymer laminated body excellent in the adhesiveness of a transparent substrate and an adhesion functional layer by containing the polymer of the polymerizable monomer which has such a structure in an adhesion functional layer. It is.
Hereinafter, such an adhesion functional layer will be described in detail.

(1) Polymerizable monomer The polymerizable monomer used in the present invention is at least one polymerizable monomer selected from the group consisting of the above formulas (I), (II), (III), (IV), and (V). It has a functional group, and the carbon content ratio is 3 or more. In the present invention, since the carbon content ratio is in the above range, the polarity of the polymerizable monomer can be approximated to the polarity of the cycloolefin-based resin constituting the transparent substrate described later. Adhesion with the transparent substrate to be improved can be improved.

The carbon content ratio of the polymerizable monomer used in the present invention is not particularly limited as long as it is within the range specified in the present invention, and is arbitrary depending on the type of cycloolefin resin constituting the transparent substrate described later. Can be determined. In particular, in the present invention, the carbon content ratio is preferably in the range of 3 to 10, particularly preferably in the range of 3 to 7, and more preferably in the range of 3 to 5. preferable. The carbon content ratio indicates that the larger the value is, the smaller the polarity of the polymerizable monomer is. Therefore, if the carbon content ratio is smaller than the above range, the polarity of the polymerizable monomer becomes too large. The adhesion between the transparent substrate and the adhesion functional layer may become insufficient, and if it is larger than the above range, the ratio of the polymerizable functional group contained in the polymerizable monomer becomes too small, This is because the solvent resistance of the adhesion functional layer may be impaired.
Here, as described above, the carbon content ratio is a value (N / M) obtained by dividing the carbon number N constituting the polymerizable monomer by the number M of elements other than carbon and hydrogen constituting the polymerizable monomer. However, the “number of carbon atoms constituting the polymerizable monomer N” means the number of carbons represented when the polymerizable monomer is represented by a molecular formula. "The number of elements other than carbon and hydrogen constituting M" means the sum of the numbers of elements other than carbon and hydrogen expressed when the polymerizable monomer is represented by a molecular formula. Therefore, for example, in the case of 1,6-hexanediol diacrylate having a molecular formula of C ₁₂ H ₁₈ O ₄ , the number of carbon atoms N constituting the polymerizable monomer is 12, other than carbon and hydrogen constituting the polymerizable monomer. Since the number of elements M is 4, the above N / M is 3. In the case of acryloylmorpholine having a molecular formula of C ₇ H ₁₁ NO ₂ , the number N of carbon atoms constituting the polymerizable monomer is 7, and the number M of elements other than carbon and hydrogen constituting the polymerizable monomer is 3 (nitrogen). + / Oxygen), the N / M is 2.3.

The polymerizable monomer used in the present invention may contain one of the polymerizable functional groups in the molecule or may contain a plurality of polymerizable functional groups. In particular, in the present invention, it is preferable to use one containing a plurality of polymerizable functional groups. This is because the solvent resistance of the adhesion functional layer in the present invention can be improved.
In addition, when the polymerizable monomer used in the present invention is formed by bonding a plurality of the above polymerizable functional groups, all the polymerizable functional groups may be the same or different from each other.

  The polymerizable monomer used in the present invention is not particularly limited as long as the carbon content ratio is within the range specified by the present invention, but has an aliphatic hydrocarbon. It is preferable that Such aliphatic hydrocarbons may be linear, branched, or cyclic. In particular, in the present invention, a linear or cyclic one is preferable. When the hydrocarbon chain is linear or cyclic, the molecular structure of the polymerizable monomer is similar to the molecular structure of the cycloolefin resin described later, so that the polarities of both are closer. This is because a polymer laminate having better adhesion can be obtained.

The polymerizable monomer used in the present invention preferably has a hydroxyl value of 150 mgKOH / g or less, more preferably 50 mgKOH / g or less, and particularly preferably 5 mgKOH / g or less.
Further, the polymerizable monomer used in the present invention preferably has an acid value of 150 mgKOH / g or less, more preferably 50 mgKOH / g or less, and particularly preferably 5 mgKOH / g or less.
When the polymerizable monomer contains a highly polar hydroxyl group or acidic group (carboxylic acid, phosphoric acid, sulfonic acid, etc.) and either the hydroxyl value or the acid value is higher than 150 mgKOH / g, the carbon content ratio is determined in the present invention. Even within the specified range, it is difficult to approximate the polarity of the polymerizable monomer to the polarity of the cycloolefin resin described later, and the adhesion between the adhesion functional layer and the transparent substrate may be reduced. Because.
Here, the hydroxyl value can be measured by a method based on JIS K0070. Moreover, the said acid value can be measured by the method based on JISK2501.

  Specific examples of the polymerizable monomer used in the present invention include, for example, polymerizable monomers represented by the following formulas (VI) and (VII).

In the above formula, X ¹ , X ² , and X ³ are each independently a polymerizable functional group of any one of the above formulas (I), (II), (III), (IV), and (V). To express. Y ¹ is a linear or branched hydrocarbon represented by —C _m H _{2m + 1} (m is an integer of 4 to 17), a cyclohexyl group, an isobornyl group, an unsubstituted group or an alkyl group. Represents a phenyl group or a biphenyl group. r ¹ , r ² , r ³ and r ⁴ are each independently 0 or 1;
Further, Y ² represents a linear or branched hydrocarbon represented by —C _n H _2n — (n is an integer of 1 to 34), a cyclohexyl group, a tricyclodecanedimethyl group, a phenyl group, Or represents a biphenyl group.

  In the present invention, among the polymerizable monomers represented by the above formulas (VI) and (VII), it is preferable to use the following polymerizable monomers (hereinafter, the numerical values in <> represent the carbon of each compound. The content ratio is indicated.).

A polymerizable monomer having a polymerizable functional group represented by the above formula (I); cyclohexyl acrylate <4.5>, isobornyl acrylate <6.5>, 1,6-hexanediol diacrylate <3>, 1 , 9-nonanediol diacrylate <3.75>, 2-methyl-1,8-octanediol diacrylate <3.75>, 2-butyl-2-ethyl-1,4-propanediol diacrylate <3. 75>, 1,10-decanediol diacrylate <3.75>, tricyclodecane dimethanol diacrylate <4.5>.
Polymerizable monomer having a polymerizable functional group represented by the above formula (II): 1,6-hexanediol divinyl ether <5>, cyclohexanediol divinyl ether <5>, cyclohexanedimethanol divinyl ether <6>, nonanediol Divinyl ether <6.5>, trimethylpropane trivinyl ether <4>.
A polymerizable monomer having a polymerizable functional group represented by the above formula (III); ethylhexyl glycidyl ether <5.5>.
A polymerizable monomer having a polymerizable functional group represented by the above formulas (III) and (IV); dipentene dioxide <5>.
A polymerizable monomer having a polymerizable functional group represented by the above formula (V); 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane <7>, di [1-ethyl (3-oxetanyl)] methyl Ether <4>.
A polymerizable monomer having a polymerizable functional group represented by the above formulas (I) and (V); 3-ethyl-3-oxetanylmethyl acrylate <3>.

  The polymer contained in the adhesion functional layer used in the present invention may be one in which only one type of the polymerizable monomer is used, or may be one in which two or more types are used. good.

  In addition, the adhesion functional layer used in the present invention contains a polymer obtained by polymerizing the polymerizable monomer, but the polymer contained in the adhesion functional layer is a polymer of the polymerizable monomer. For example, it can be clarified by NMR analysis.

(2) Adhesive Functional Layer As described above, the adhesive functional layer used in the present invention contains a polymer of the polymerizable monomer. Therefore, as an aspect of the said adhesion functional layer, the aspect which consists only of the polymer of the said polymerizable monomer, and the aspect in which another compound is contained other than the polymer of the said polymerizable monomer can be mentioned. In the present invention, any of these embodiments can be suitably used, but among them, an embodiment in which other compounds are included in addition to the polymerized polymerizable monomer is preferable. It is because it becomes possible to provide arbitrary functionality to the contact | adherence functional layer in this invention by containing another compound other than the polymer of the said polymerizable monomer.

  As said other compound used for this invention, what can provide desired functionality to the said contact | adherence functional layer can be selected arbitrarily and used. Examples of such other compounds include ultraviolet curable resins. By containing an ultraviolet curable resin in the adhesion functional layer, a stress relaxation function can be imparted to the adhesion functional layer. Here, specific examples of the ultraviolet curable resin will be described in detail in the section of “B. Retardation film” described later, and thus description thereof is omitted here.

  Moreover, a photo-alignment material can be mentioned as said other compound. By containing the photo-alignment material in the adhesion functional layer, it becomes possible to impart alignment to the liquid crystal material in the adhesion functional layer. Therefore, by including a photo-alignment material in the adhesion functional layer, it is not necessary to form an alignment layer when a retardation film is produced using the polymer laminate of the present invention. Here, since the specific example of the said photo-alignment material is explained in full detail in the section of "B. Retardation film" mentioned later, description here is abbreviate | omitted.

  Examples of the other compound include a leveling agent, a polymerization initiator, and polymer fine particles.

  The thickness of the adhesion functional layer used in the present invention can be arbitrarily determined according to the type of the polymerizable monomer, the function to be imparted to the adhesion functional layer, etc., but is usually within the range of 0.5 μm to 10 μm. It is preferable that it is in the range of 1 micrometer-8 micrometers especially.

2. Transparent substrate Next, the transparent substrate used in the present invention will be described. The transparent substrate used in the present invention is made of a cycloolefin resin.

  Here, the cycloolefin resin in the present invention means a resin having a monomer unit composed of a cyclic olefin (cycloolefin). Moreover, as a monomer which consists of the said cyclic olefin, a norbornene, a polycyclic norbornene-type monomer, etc. can be mentioned, for example.

  In addition, the cycloolefin resin used in the present invention may be a homopolymer of a monomer composed of the above cyclic olefin, or a copolymer.

The cycloolefin-based resin used in the present invention is not particularly limited as long as a transparent substrate having desired transparency can be obtained. Among them, the cycloolefin resin used in the present invention preferably has a saturated water absorption at 23 ° C. of 1% by weight or less, and more preferably in the range of 0.1% by weight to 0.7% by weight. . This is because by using such a cycloolefin-based resin, it is possible to make the optical functional film of the present invention less susceptible to changes in optical properties and dimensions due to water absorption.
Here, the saturated water absorption is obtained by immersing in 23 ° C. water for 1 week according to ASTM D570 and measuring the increased weight.

  In addition, the cycloolefin resin used in the present invention preferably has a glass transition point in the range of 100 ° C to 200 ° C, particularly preferably in the range of 100 ° C to 180 ° C, and in particular, 100 ° C. It is preferable to be within a range of ˜150 ° C. This is because, when the glass transition point is within the above range, the optical functional film of the present invention can be more excellent in heat resistance and processability.

  Examples of such norbornene-based resins include those having a structural unit represented by the following formula (a) and those having a structural unit represented by the following formula (a) and the following formula (b). be able to.

Here, in the above formula (a), t and u each independently represent 0 or a positive integer, except when t and u are 0 at the same time. A represents an ethylene group or a vinylene group, and R ^{11 to} R ¹⁴ are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or — (CH ₂ ) n—COOR ( n represents 0 to 5, and R represents an alkyl group having 1 to 12 carbon atoms.
Here, R ¹¹ or R ¹² and R ¹³ or R ¹⁴ may be bonded to each other to form a carbocyclic or heterocyclic ring. Furthermore, the carbocycle or heterocycle may be a monocyclic structure or a polycyclic structure.

In the above formula (b), B represents an ethylene group or a vinylene group. R ^{15 to} R ¹⁸ each independently represent a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 30 carbon atoms. Further, R ¹⁵ and R ¹⁶ , or R ¹⁷ and R ¹⁸ may be integrated to form a divalent hydrocarbon group.

  Specific examples of the cycloolefin resin used in the present invention include, for example, Topas manufactured by Ticona, Arton manufactured by JSR, ZEONOR manufactured by Nippon Zeon, ZEONEX manufactured by Nippon Zeon, and Appel manufactured by Mitsui Chemicals. it can.

  In the transparent substrate used in the present invention, only one type of the above cycloolefin-based resin may be used, or two or more types may be used.

The transparency of the transparent substrate used in the present invention may be arbitrarily determined according to the use of the polymer laminate of the present invention, but usually the transmittance in the visible light region is preferably 80% or more, More preferably, it is 90% or more. When the transmittance is in the above range, for example, when the polymer laminate of the present invention is used for a viewing angle compensation film of a liquid crystal display device, it is possible to prevent the display luminance of the liquid crystal display device from being lowered. Because it can.
Here, the transmittance of the transparent substrate can be measured according to JIS K7361-1 (Testing method for total light transmittance of plastic transparent material).

  The thickness of the transparent substrate used for this invention will not be specifically limited if it is in the range which can provide desired self-supporting property. Especially in this invention, it is preferable to exist in the range of 25 micrometers-1000 micrometers, and it is especially preferable to exist in the range of 30 micrometers-100 micrometers. This is because if the thickness of the transparent substrate is thinner than the above range, the necessary self-supporting property may not be imparted to the transparent substrate of the present invention. Further, if the thickness is thicker than the above range, for example, when cutting the polymer laminate of the present invention, processing waste may increase or the cutting blade may be worn quickly. .

  The configuration of the transparent substrate in the present invention is not limited to a configuration composed of a single layer, and may have a configuration in which a plurality of layers are laminated. When it has the structure by which the several layer was laminated | stacked, the layer of the same composition may be laminated | stacked, and the several layer which has a different composition may be laminated | stacked.

The transparent substrate used in the present invention may exhibit retardation. Such retardation is not particularly limited as long as a desired refractive index anisotropy can be imparted to the polymer laminate according to the use of the polymer laminate of the present invention. In particular, in the present invention, it is preferable that the transparent substrate has a property as a λ / 4 plate or a property as a λ / 2 plate.
Here, “having properties as a λ / 4 plate” usually means that the absolute value of the in-plane retardation of the transparent substrate (hereinafter sometimes simply referred to as “Re”) is the wavelength of the incident light. In particular, the transparent substrate used in the present invention preferably has an absolute value of Re in the range of 120 nm to 150 nm.
Further, the above-mentioned “having properties as a λ / 2 plate” usually means that the absolute value of Re of the transparent substrate shows a value half of the wavelength of incident light. However, the transparent substrate used in the present invention preferably has an absolute value of Re in the range of 250 nm to 300 nm at a wavelength of 550 nm.
Here, Re refers to the refractive index Nx in the fast axis direction (the direction in which the refractive index is the smallest) and the refractive index Ny in the slow axis direction (the direction in which the refractive index is the largest) of the transparent substrate, and transparent It is a value represented by the equation Re = (Nx−Ny) × d depending on the thickness d of the substrate, and is measured by an automatic birefringence measuring device (trade name: KOBRA-21ADH, manufactured by Oji Scientific Instruments). Can do.

Further, the transparent substrate used in the present invention preferably has a thickness direction retardation (hereinafter sometimes simply referred to as “Rth”) in the range of 0 nm to 100 nm, and particularly in the range of 0 nm to 50 nm. It is preferable that
Here, Rth is the refractive index Nx in the fast axis direction (the direction in which the refractive index is the smallest) and the refractive index Ny in the slow axis direction (the direction in which the refractive index is the largest) in the plane of the transparent substrate, It is a value represented by the formula of Rth = {(Nx + Ny) / 2−Nz} × d depending on the refractive index Nz in the thickness direction and the thickness d of the transparent substrate.
The Rth of the transparent substrate used in the present invention can be measured by the same method as Re described above.

3. Applications of Polymer Laminates The applications of the polymer laminates of the present invention can be used for all applications where a transparent film with low water permeability is required, and in particular, retardation films used for liquid crystal display devices. Or it can use suitably for optical function films, such as an antireflection film. As an aspect of using the polymer laminate of the present invention as such an optical functional film, an aspect in which the above-mentioned adhesion functional layer is used with an optical function and a desired optical function are expressed in the polymer laminate of the present invention. And an embodiment in which optical function layers are stacked and used.

  As an aspect of using the polymer laminate of the present invention as an optical functional film by imparting an optical function to the adhesion functional layer, for example, a retardation increasing agent such as a liquid crystal compound is added to the adhesion functional layer. Examples include an embodiment and an embodiment in which polymer fine particles are added to the adhesion functional layer.

  On the other hand, as an aspect of using the polymer laminate of the present invention as an optical functional film by laminating an optical functional layer that expresses a desired optical function, for example, in the section of “B. Retardation film” described later. A mode in which a retardation layer that expresses retardation is laminated on the adhesion functional layer as described can be exemplified.

4). Production method of polymer laminate The production method of the polymer laminate of the present invention is not particularly limited as long as it is a method capable of producing a polymer laminate having the above-described configuration. As such a method, for example, the method described in the section of “C. Method for producing polymer laminate” described later can be exemplified.

B. Next, the retardation film of the present invention will be described. The retardation film of the present invention is characterized in that a retardation layer containing a liquid crystal material is formed on the adhesion functional layer of the polymer laminate of the present invention.

  Such a retardation film of the present invention will be described with reference to the drawings. FIG. 2 is a schematic view showing an example of the retardation film of the present invention. As illustrated in FIG. 2, the retardation film 20 of the present invention uses the polymer laminate 10 of the present invention composed of the transparent substrate 1 and the adhesion functional layer 2. The retardation layer 3 containing a liquid crystal material is formed.

According to the present invention, by using the polymer laminate of the present invention in which a transparent substrate made of a cycloolefin resin is used, excellent adhesion between the adhesion functional layer and the transparent substrate is achieved. And the retardation film excellent in the temporal stability of the optical property can be obtained.
Hereinafter, the retardation film of the present invention will be described in detail.

  The retardation film of the present invention has at least the polymer laminate and a retardation layer, and may have other layers as necessary. Hereinafter, each structure used for the retardation film of the present invention will be described in detail.

1. Next, the retardation layer used in the present invention will be described. The retardation layer of the present invention contains a liquid crystal material and has a function of imparting desired retardation (birefringence) to the retardation film of the present invention.

  The liquid crystal material used for this invention will not be specifically limited if it is a material which can express desired retardation in the retardation film used for this invention. Among these, in the present invention, a liquid crystal material exhibiting a nematic phase is preferably used. This is because nematic liquid crystals are easily arranged regularly as compared with liquid crystal materials exhibiting other liquid crystal phases.

  Further, as the liquid crystal material used in the present invention, it is preferable to use a polymerizable liquid crystal material having a polymerizable functional group. This is because the polymerizable liquid crystal materials can be polymerized with each other via a polymerizable functional group, so that the mechanical strength of the retardation layer in the present invention can be improved. In addition, the stability of the alignment of the liquid crystal material can be improved.

  As the polymerizable functional group, various polymerizable functional groups that are polymerized by the action of ionizing radiation such as ultraviolet rays and electron beams, or heat are used. Representative examples of these polymerizable functional groups include radically polymerizable functional groups or cationic polymerizable functional groups. Further, representative examples of radically polymerizable functional groups include functional groups having at least one addition-polymerizable ethylenically unsaturated double bond, and specific examples include vinyl groups having or not having substituents, An acrylate group (generic name including an acryloyl group, a methacryloyl group, an acryloyloxy group, and a methacryloyloxy group) and the like can be given. Specific examples of the cationic polymerizable functional group include an epoxy group. In addition, examples of the polymerizable functional group include an isocyanate group and an unsaturated triple bond. In the present invention, among these polymerizable functional groups, a functional group having an ethylenically unsaturated double bond is preferably used from the viewpoint of the process.

  The polymerizable liquid crystal material used in the present invention may have a plurality of the above-mentioned polymerizable functional groups, or may have only one. In the present invention, a polymerizable liquid crystal material having a plurality of polymerizable functional groups and a polymerizable liquid crystal material having only one polymerizable functional group may be mixed and used.

  Specific examples of the polymerizable liquid crystal material used in the present invention include compounds described in, for example, JP-A-7-258638, JP-A-10-508882, and JP-A-2003-623623. Can be mentioned. In particular, in the present invention, it is preferable to use compounds represented by the following chemical formulas (1) to (10) as the polymerizable liquid crystal material.

  The liquid crystal material used in the present invention may be one kind or a mixture of two or more kinds. In the present invention, when two or more kinds of liquid crystal materials are mixed and used, a polymerizable liquid crystal material and a liquid crystal material having no polymerizable functional group may be mixed and used.

  The retardation layer in the present invention may contain a compound other than the liquid crystal material. Such other compounds are not particularly limited as long as they do not impair the alignment state of the liquid crystal material in the retardation layer and the optical properties of the retardation layer, and are not particularly limited. It can be appropriately selected and used according to the application of the retardation film. Examples of such other compounds include chiral agents, polymerization initiators, polymerization inhibitors, plasticizers, surfactants, and silane coupling agents. In particular, in the present invention, when the polymerizable liquid crystal material is used as the liquid crystal material, it is preferable to use a polymerization initiator or a polymerization inhibitor as the other compound.

  Examples of the polymerization initiator include benzophenone, methyl o-benzoylbenzoate, 4,4-bis (dimethylamine) benzophenone, 4,4-bis (diethylamine) benzophenone, α-amino acetophenone, 4,4-dichloro. Benzophenone, 4-benzoyl-4-methyldiphenyl ketone, dibenzyl ketone, fluorenone, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2-hydroxy-2-methylpropiophenone, p- tert-Butyldichloroacetophenone, thioxanthone, 2-methylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, diethylthioxanthone, benzyldimethyl ketal, benzylmethoxyethyl acetal, benzo Methyl ether, benzoin butyl ether, anthraquinone, 2-tert-butylanthraquinone, 2-amylanthraquinone, β-chloroanthraquinone, anthrone, benzanthrone, dibenzsuberone, methyleneanthrone, 4-azidobenzylacetophenone, 2,6-bis (p- Azidobenzylidene) cyclohexane, 2,6-bis (p-azidobenzylidene) -4-methylcyclohexanone, 2-phenyl-1,2-butadion-2- (o-methoxycarbonyl) oxime, 1-phenyl-propanedione-2 -(O-ethoxycarbonyl) oxime, 1,3-diphenyl-propanetrione-2- (o-ethoxycarbonyl) oxime, 1-phenyl-3-ethoxy-propanetrione-2- (o-benzoyl) oxy , Michler's ketone, 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone, naphthalene Sulfonyl chloride, quinoline sulfonyl chloride, n-phenylthioacridone, 4,4-azobisisobutyronitrile, diphenyl disulfide, benzthiazole disulfide, triphenylphosphine, camphorquinone, Adeka N1717, carbon tetrabromide, tri Examples include combinations of photoreducing dyes such as bromophenyl sulfone, benzoin peroxide, eosin, and methylene blue with reducing agents such as ascorbic acid and triethanolamine. In this invention, these photoinitiators can be used 1 type or in combination of 2 or more types.

  Furthermore, when using the said photoinitiator, a photoinitiator adjuvant can be used together. Examples of such photopolymerization initiation assistants include tertiary amines such as triethanolamine and methyldiethanolamine, and benzoic acid derivatives such as ethyl 2-dimethylaminoethylbenzoate and ethyl 4-dimethylamidebenzoate. Yes, but not limited to these.

  Examples of the polymerization inhibitor include diphenylpicrylhydrazide, tri-p-nitrophenylmethyl, p-benzoquinone, p-tert-butylcatechol, picric acid, copper chloride, methylhydroquinone, methoquinone, tert-butylhydroquinone and the like. Although a polymerization inhibitor for the reaction can be used, a hydroquinone polymerization inhibitor is preferred from the viewpoint of storage stability, and methyl hydroquinone is particularly preferred.

  Moreover, the compounds as shown below can be added to the retardation layer in the present invention within a range not impairing the object of the present invention. Examples of compounds that can be added include polyester (meth) acrylate obtained by reacting (meth) acrylic acid with a polyester prepolymer obtained by condensing polyhydric alcohol and monobasic acid or polybasic acid; A polyurethane (meth) acrylate obtained by reacting a compound having two isocyanate groups with each other and then reacting the reaction product with (meth) acrylic acid; bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolak Type epoxy resins, polycarboxylic acid polyglycidyl esters, polyol polyglycidyl ethers, aliphatic or cycloaliphatic epoxy resins, amino group epoxy resins, triphenolmethane type epoxy resins, dihydroxybenzene type epoxy resins and the like (meta Acu Photopolymerizable compounds such as epoxy (meth) acrylate obtained by reacting Le acid; photopolymerizable liquid crystal compound having an acryl group or methacryl group and the like.

  The alignment state of the liquid crystal material in the retardation layer in the present invention is not particularly limited as long as it is an alignment state capable of expressing desired optical characteristics in the retardation film used in the present invention. Examples of such an alignment state include a state in which the liquid crystal material is aligned in parallel to the transparent substrate and a state in which the liquid crystal material is aligned perpendicular to the transparent substrate. The former liquid crystal structure is called a homogeneous structure (parallel alignment structure). By having such a structure, the retardation film used in the present invention can be optically imparted with properties as an A plate. The latter liquid crystal structure is called a homeotropic structure (vertical alignment structure), and by having such a structure, the retardation film of the present invention can be imparted with the property as an optically positive C plate. it can.

  Further, the alignment state of the liquid crystal material may be a cholesteric alignment state in which the liquid crystal material exhibits a regular spiral structure. By having such an arrangement state, the retardation film used in the present invention can be imparted with properties as an optically negative C plate.

  When the alignment state of the liquid crystal material is changed to a cholesteric alignment state, a chiral agent that induces a helical structure in the retardation layer is usually added. As such a chiral agent, a low molecular compound having axial asymmetry in the molecule is preferably used. As a chiral agent used for this invention, the compound represented by following formula (11), (12) or (13) can be mentioned, for example.

In the general formula (11) or (12), R ⁵ represents hydrogen or a methyl group. Y is any one of formulas (i) to (xxiv) shown above, and among them, any one of formulas (i), (ii), (iii), (v), and (vii) It is preferable that Moreover, although c and d which show the chain length of an alkylene group can each take arbitrary integers in the range of 2-12, it is preferable that it is the range of 4-10, and is the range of 6-9. Is more preferable.

  The thickness of the retardation layer in the present invention is not particularly limited as long as it is within a range in which desired optical characteristics can be imparted to the retardation film used in the present invention, depending on the type of the liquid crystal material and the like. It is preferably in the range of 10 μm, in particular, preferably in the range of 0.5 μm to 5 μm, particularly preferably in the range of 1 μm to 3 μm.

The retardation layer in the present invention exhibits retardation, but such retardation can be arbitrarily adjusted according to the use of the retardation film of the present invention. Among them, the retardation layer used in the present invention preferably has properties as a λ / 4 plate or properties as a λ / 2 plate.
Here, “having properties as a λ / 4 plate” usually means that the absolute value of Re of the retardation layer indicates a value of ¼ of the wavelength of incident light. In particular, the retardation layer in the present invention preferably has an absolute value of Re in the range of 120 nm to 150 nm at a wavelength of 550 nm.
In addition, the above-mentioned “having properties as a λ / 2 plate” usually means that the absolute value of Re of the retardation layer shows a value that is ½ of the wavelength of incident light. In particular, the retardation layer in the present invention preferably has an absolute value of Re in the range of 250 nm to 300 nm at a wavelength of 550 nm.
The definition and measurement method of Re of the retardation layer is the same as the method described in the above section “A. Polymer laminate”, and thus the description thereof is omitted here.

2. Next, the polymer laminate used in the present invention will be described. The polymer laminate used in the present invention is not particularly limited as long as it has the configuration described in the above section “A. Polymer laminate”. Especially in this invention, it is preferable to use what has the stress relaxation function in which the said contact | adherence functional layer relieves the external stress added to the retardation film of this invention as said polymer laminated body. The adhesion functional layer having such a stress relaxation function prevents the retardation layer, the alignment layer, and the like from being damaged when an external stress is applied to the retardation film of the present invention. Because it can be done. In the present invention, when a photo-alignment film is used as the alignment film, it is particularly preferable to use a film having such a stress relaxation function. Since the photo-alignment film has low mechanical strength, for example, the external force applied when the retardation film of the present invention is formed in a long roll shape and wound may be damaged in its form and orientation regulating force. This is because the above-mentioned adhesion functional layer has such a stress relaxation function, so that such a fear can be eliminated.

  As such a polymer laminate in which the adhesion functional layer has the stress relaxation function, those obtained by adding a resin material imparting a stress relaxation function to the adhesion functional layer are usually used. Such a resin material is not particularly limited as long as it can impart desired hardness, elastic modulus and the like to the adhesion functional layer, and any resin material can be used. In particular, in the present invention, it is preferable to use an active energy ray-curable resin in which three-dimensional crosslinking is caused by active energy rays as the resin material.

  Examples of the active energy ray curable resin include an ultraviolet curable resin in which three-dimensional crosslinking is caused by ultraviolet rays and an electron beam curable resin in which three-dimensional crosslinking is caused by an electron beam. In this case, it is preferable to use an ultraviolet curable resin.

  Further, as the ultraviolet curable resin, the wavelength of ultraviolet rays that cause three-dimensional crosslinking is preferably in the range of 100 to 450 nm, and more preferably in the range of 250 to 400 nm. This is because ultraviolet rays in this wavelength range can be easily obtained with a general light source.

  Specific examples of the ultraviolet curable resin used in the present invention include monofunctional monomers such as reactive ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, N-vinylpyrrolidone, polyfunctional monomers, poly Methylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, triethylene (polypropylene) glycol (meth) diacrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (Meth) acrylate, neopentyl glycol di (meth) acrylate, isocyanuric acid EO-modified diacrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meta Acrylate, bisphenol fluorene derivatives, bisphenoxyethanolfluorene acrylate, and bisphenol fluorene Epo Kiki acrylate. Among these, in the present invention, as the ultraviolet curable resin, triethylene (polypropylene) glycol diacrylate, 1,6-hexanediol di (meth) acrylate, isocyanuric acid EO-modified diacrylate, bisphenolfluorene derivative, caprolactone-modified urethane acrylate It is preferable to use caprolactone-modified acrylate.

  In the present invention, these ultraviolet curable resins may be used alone or in combination of two or more.

  When the ultraviolet curable resin is used as the resin material used in the present invention, it is preferable that the adhesion functional layer contains a photopolymerization initiator and a photosensitizer. Examples of the photopolymerization initiator include acetophenones, benzophenones, Michler benzoylbenzoate, α-amyloxime ester, tetramethylchuram monosulfide, and thioxanthones.

  As the photopolymerization initiator, when the polymerizable monomer has a polymerizable functional group represented by the formula (I), it is preferable to use a photoradical polymerization initiator, while the polymerizable monomer is the above When it has a polymerizable functional group represented by the formulas (II), (III), (IV), and (V), it is preferable to use a photocationic polymerization initiator. A polymerizable monomer having a polymerizable functional group represented by the formula (I) and a polymerizable functional group represented by the above formulas (II), (III), (IV), and (V) in the coating liquid for forming an adhesion functional layer In the case of containing both of the polymerizable monomers having, it is preferable to use a compound that can be used as a radical photopolymerization initiator and a cationic photopolymerization initiator.

  Examples of the photo radical polymerization initiator include benzyl, benzoin isobutyl ether, benzoin isopropyl ether, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-benzoyl-4′-methyldiphenyl sulfide, benzylmethyl ketal, dimethylaminomethyl. Benzoate, 2-n-butoxyethyl-4-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, 3,3′-dimethyl-dimethyl-4-methoxybenzophenone, methylobenzoylformate, 2-methyl-1- ( 4- (methylthio) phenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 1-hydroxycyclohexyl Erniketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 2-chlorothioxanthone, 2,4- Examples include diethylthioxanthone, 2,4-diisopropylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 1-chloro-4-proxythioxanthone, and the like.

  Examples of the cationic photopolymerization initiator include sulfonic acid esters, imide sulfonates, dialkyl-4-hydroxysulfonium salts, arylsulfonic acid-p-nitrobenzyl esters, silanol-aluminum complexes, (η6-benzene) (η5-cyclo Pentadienyl) iron (II) and the like. More specifically, benzoin tosylate, 2,5-dinitrobenzyl tosylate, N-tosicphthalimide and the like can be mentioned.

  Furthermore, examples of the compound that can be used as the photo radical polymerization initiator and the photo cation polymerization initiator include aromatic iodonium salts, aromatic sulfonium salts, aromatic diazonium salts, aromatic phosphonium salts, triazine compounds, An iron arene complex etc. can be illustrated. More specifically, chlorides present or absent in iodine such as diphenyliodonium, ditolyliodonium, bis (p-tert-butylphenyl) iodonium, bis (p-chlorophenyl) iodonium; bromide, borofluoride, hexafluorophosphate salt, Iodonium salts such as hexafluoroantimonate salts, chlorides of sulfonium such as triphenylsulfonium, 4-tert-butyltriphenylsulfonium, tris (4-methylphenyl) sulfonium, bromides, borofluorides, hexafluorophosphate salts, hexafluoro Sulfonium salts such as antimonate salts, 2,4,6-tris (trichloromethyl) -1,3,5-triazine, 2-phenyl-4,6-bis (trichloromethyl) -1,3,5-triazine, 2 − And the like Chiru 4,6-bis (trichloromethyl) -1,3,5-2,4,6-substituted-1,3,5-triazine compounds such as triazines.

  Furthermore, when using the said photoinitiator, a photoinitiator adjuvant can be used together. Examples of such photopolymerization initiation assistants include tertiary amines such as triethanolamine and methyldiethanolamine, and benzoic acid derivatives such as ethyl 2-dimethylaminoethylbenzoate and ethyl 4-dimethylamidebenzoate. Yes, but not limited to these.

  The addition amount of such a photopolymerization initiator is preferably 0.01 mass or more, more preferably 0.1 mass or more, particularly 1 mass% or more with respect to the polymerizable monomer. Preferably there is. This is because if the addition amount of the photopolymerization initiator is less than the above range, the amount of ultraviolet irradiation necessary to polymerize the polymerizable monomer may be excessively increased.

  Examples of the photosensitizer include n-butylamine, triethylamine, and poly-n-butylphosphine.

  The content when the resin material is contained in the adhesion functional layer is not particularly limited as long as it is within a range in which a desired stress relaxation function can be imparted to the adhesion functional layer according to the type of the resin material and the like. Especially in this invention, it is preferable to exist in the range of 1 weight part-50 weight part with respect to 100 weight part of polymers of the said polymerizable monomer contained in an adhesion functional layer, and especially 5 weight part-30 weight part. It is preferably within the range of parts. If the content of the resin material is less than the above range, the adhesion functional layer may not be imparted with a desired stress relaxation function, and if it exceeds the above range, the adhesion between the adhesion functional layer and the transparent substrate is impaired. Because there is a possibility.

As the hardness of the adhesion functional layer in the case where the polymer laminate used in the present invention has a stress relaxation function in the adhesion functional layer, when external stress is applied to the retardation film of the present invention, If it is in the range which can prevent that a phase difference layer etc. are damaged, it will not specifically limit, What is necessary is just to determine suitably according to the use etc. of the phase difference film of this invention. In particular, in the present invention, it is preferable that the universal hardness in a thickness 4μm is in the range of ^{200N / mm 2 ~800N / mm 2} , more preferably in the range of ^{300N / mm 2 ~700N / mm 2} , and even more preferably within the range of ^{400N / mm 2 ~600N / mm 2} . Here, the universal hardness means that the Vickers pyramid indenter is pushed into the adhesion functional layer at a test load F (0.4 mN to 1 N), the indentation depth displacement amount of the Vickers pyramid indenter is measured, and the adhesion functional layer is measured. The universal hardness value (HU) is determined by the formula HU = F / (26.3 × h ² ). The universal hardness value (HU) is obtained from the test load F and the indentation surface area of the indenter, and the surface area can be obtained from the indentation depth (h).

  The elastic modulus of the adhesion functional layer when the polymer laminate used in the present invention has a stress relaxation function in the adhesion functional layer is the elasticity defined by the value of elastic deformation amount / total deformation amount. The rate is preferably in the range of 0.2 to 0.6, and more preferably in the range of 0.3 to 0.5. Here, the elastic modulus defined by the value of the elastic deformation amount / total deformation amount can be calculated from, for example, the elastic deformation amount and the plastic deformation amount obtained during the universal hardness measurement.

  Since matters other than the above regarding the polymer laminate used in the present invention are the same as those described in the above section “A. Polymer laminate”, description thereof is omitted here.

3. Other Layers In the retardation film of the present invention, other layers other than the polymer laminate and the retardation layer may be formed. As such other layers, an alignment layer formed between the adhesion functional layer of the polymer laminate and the retardation layer and having an alignment regulating force for the liquid crystal material contained in the retardation layer, A stress relaxation layer formed between the adhesion functional layer and the retardation layer and having a stress relaxation function; and an additive formed between the adhesion functional layer and the retardation layer and contained in the transparent substrate. Examples thereof include a barrier layer having a shielding function for preventing the agent and the like from moving to the retardation layer. Hereinafter, these layers will be described.

(1) Orientation layer First, the orientation layer will be described. The alignment layer used in the present invention is formed between the adhesion functional layer of the polymer laminate and the retardation layer, and has an alignment regulating force to align the liquid crystal material contained in the retardation layer. It is.

The alignment film used in the present invention is not particularly limited as long as it has an alignment regulating force for the liquid crystal material used in the above-described retardation layer. As such an alignment film, a light containing a rubbing film that expresses an alignment regulating force by rubbing the surface of a polymer film or a photo-alignment material that expresses an alignment regulating force by a photo-alignment method is usually used. An alignment film is used. In particular, in the present invention, it is preferable to use the photo-alignment film. This is because the use of the photo-alignment film makes it easy to adjust the alignment direction of the liquid crystal material, making it easy to obtain a retardation film having a slow axis in any direction.
In addition, the rubbing film may cause a bright spot defect when the retardation film of the present invention is used for a liquid crystal display device, for example, due to dust generated in the rubbing treatment for expressing the alignment regulating force. However, since the photo-alignment film can express the alignment regulating force in a non-contact manner by irradiating light, there are few such problems.
Here, the “photo-alignment method” is a method for expressing the alignment regulating force (anisotropy) of the alignment layer by irradiating the alignment layer with light having an arbitrary polarization state (polarized light).

  The photo-alignment material used in the present invention includes a photoisomerization material that reversibly changes the alignment regulation force by changing only the molecular shape by irradiating polarized light, and light that changes the molecule itself by irradiating polarized light. It can be roughly divided into reaction materials. In the present invention, any of the above-mentioned photoisomerization material and photoreaction material can be suitably used, and among these, it is more preferable to use a photoreaction material. As described above, the photoreactive material is a material that reacts with polarized light to express an orientation regulating force by irradiating with polarized light, and therefore can irreversibly express an orientation regulating force. This is because the regulatory stability over time is excellent.

  The photoreactive material can be further classified according to the type of reaction caused by polarized light irradiation. Specifically, a photodimerization type material that develops an alignment regulation force by causing a photodimerization reaction, a photodegradable material that produces an orientation regulation force by producing a photodecomposition reaction, an orientation regulation by producing a photobinding reaction It can be divided into a photocoupled material that expresses force, and a photolytic-coupled material that develops alignment regulation force by causing a photodecomposition reaction and a photocoupled reaction. In the present invention, any of such a photodimerization type material, photodecomposition type material, photocoupling type material, and photodecomposition-coupling type material can be suitably used, and among these, a photodimerization type material is used. It is more preferable.

  The photodimerization-type material used for this invention will not be specifically limited if it is a material which can express an orientation control force by producing photodimerization reaction. Especially in this invention, it is preferable that the wavelength of the light which produces a photodimerization reaction exists in the range of 200 nm-300 nm.

  Examples of such a photodimerization type material include a polymer having cinnamate, coumarin, benzylidenephthalimidine, benzylideneacetophenone, diphenylacetylene, stilbazole, uracil, quinolinone, maleinimide, or a cinnamilidene acetic acid derivative. In particular, in the present invention, a polymer having cinnamate or at least one of coumarin, a polymer having cinnamate and coumarin is preferably used. Specific examples of such a photodimerization type material include compounds described in JP-A-9-118717, JP-A-10-506420, and JP-A-2003-505561.

  As the cinnamate and coumarin in the present invention, those represented by the following formulas Ia and Ib are preferably used.

In the above formula, A represents pyrimidine-2,5-diyl, pyridine-2,5-diyl, 2,5-thiophenylene, 2,5-furylene, 1,4- or 2,6-naphthylene, Unsubstituted, fluorine, chlorine or a cyclic, linear or branched alkyl residue of 1 to 18 carbon atoms (unsubstituted or mono- or polysubstituted by fluorine, chlorine, 1 Represents phenylene which is mono- or polysubstituted by two or more non-adjacent —CH ₂ — groups which may be independently substituted by the group C.
Wherein B represents a hydrogen atom or a group capable of reacting or interacting with a second substance, such as a polymer, oligomer, monomer, photoactive polymer, photoactive oligomer and / or photoactive monomer or surface. Represents.
In the above formulae, C represents —O—, —CO—, —CO—O—, —O—CO—, —NR ¹¹ —, —NR ¹¹ —CO—, —CO—NR ¹¹ —, —NR ¹¹ — CO—O—, —O—CO—NR ¹¹ —, —NR ¹¹ —CO—NR ¹¹ —, —CH═CH—, —C≡C—, —O—CO—O— and —Si (CH ₃ ) _It represents a group selected from _2- O—Si (CH ₃ ) ₂ — (R ¹¹ represents a hydrogen atom or lower alkyl).
In the above formula, D represents —O—, —CO—, —CO—O—, —O—CO—, —NR ¹¹ —, —NR ¹¹ —CO—, —CO—NR ¹¹ —, —NR ¹¹ —. CO—O—, —O—CO—NR ¹¹ —, —NR ¹¹ —CO—NR ¹¹ —, —CH═CH—, —C≡C—, —O—CO—O— and —Si (CH ₃ ). _It represents a group selected from _2- O—Si (CH ₃ ) ₂ — (R ¹¹ represents a hydrogen atom or lower alkyl), an aromatic group or an alicyclic group.
In the above formula, S ₁ and S ₂ are independently of each other a single bond or a spacer unit, for example a linear or branched alkylene group having 1 to 40 carbon atoms (unsubstituted, fluorine or chlorine Mono- or poly-substituted, and one or more non-adjacent —CH ₂ — groups may be independently substituted by the group D, but the oxygen atoms are not directly bonded to each other).
In the above formula, Q represents an oxygen atom or —NR ¹¹ — (R ¹¹ represents a hydrogen atom or lower alkyl).
In the above formula, X and Y are independently of each other hydrogen, fluorine, chlorine, cyano, alkyl having 1 to 12 carbon atoms (optionally substituted by fluorine and optionally not one or more adjacent). The —CH ₂ — group is substituted by —O—, —CO—O—, —O—CO— and / or —CH═CH—.

  In the present invention, among the cinnamates represented by the above formula and coumarins, those described in JP-T-2004-536185 are preferably used.

  When using a photo-alignment film as the alignment layer in the present invention, the alignment layer may contain other materials in addition to the photo-alignment material. As such other materials, monomers or oligomers having one or more functional groups are usually used. Examples of such a monomer or oligomer include monofunctional monomers having an acrylate functional group (for example, reactive ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, N-vinylpyrrolidone) and many others. Functional monomers (for example, polymethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, triethylene (polypropylene) glycol diacrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri ( (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate And isocyanuric acid poly (meth) acrylate (for example, isocyanuric acid EO diacrylate)) and bisphenolfluorene derivatives (for example, bisphenoxyethanol full orange acrylate, bisphenol full orange epoxy acrylate) etc. be able to.

  The monomer or oligomer used in the present invention is preferably a polymerizable liquid crystal material. When a polymerizable liquid crystal material is contained in a retardation layer described later, the polymerizable liquid crystal material preferably includes the same type of polymerizable liquid crystal material contained in the retardation layer.

  Furthermore, when the above monomer or oligomer is used as a method for producing the retardation film used in the present invention, a method in which the film is rolled when the alignment layer is laminated on the transparent substrate, the alignment layer is at room temperature (20 It is preferable to use a material that becomes solid at ˜25 ° C.). In this case, it is preferable to use a monomer or oligomer that is solid at room temperature (20 to 25 ° C.). Thereby, even when the roll is wound when the alignment layer is laminated on the transparent substrate, blocking due to the alignment layer sticking to the back surface of the transparent substrate can be prevented.

  The content of the monomer or oligomer is not particularly limited as long as it is within a range in which the alignment layer and a retardation layer described later can be adhered with desired strength. In particular, in the present invention, the range of 0.01 to 3 times the mass of the photoreactive material is preferable, and the range of 0.05 to 1.5 times is particularly preferable. This is because if the content is less than the above range, the alignment layer and the retardation layer may not be adhered with desired strength. Moreover, it is because there exists a possibility that the orientation control force of an orientation layer may fall when more than the said range.

  The thickness of the alignment layer in the present invention is preferably in the range of 0.01 μm to 0.5 μm, and more preferably in the range of 0.02 μm to 0.2 μm.

(2) Stress relaxation layer Next, the stress relaxation layer will be described. The stress relaxation layer used in the present invention is formed between the adhesion functional layer and the retardation layer and has a stress relaxation function. In the present invention, such a stress relaxation layer is preferably formed in the case where, for example, a polymer layered body in which the adhesion functional layer does not have a stress relaxation function is used. As the stress relaxation layer used in the present invention, a layer made of the above-described resin material is preferably used.

(3) Barrier layer Next, the barrier layer will be described. The barrier layer used in the present invention is formed between the adhesion functional layer and the retardation layer, and has a shielding function for preventing additives contained in the transparent substrate from moving to the retardation layer. I have it. The barrier layer used in the present invention is not particularly limited as long as it has the above shielding function. Examples of such a barrier layer include those made of a polymer of a low molecular weight monomer and those made of an inorganic transparent film formed by a vapor deposition method or the like.

4). Retardation film The retardation of the retardation film used in the present invention can be determined as appropriate according to the use of the retardation film of the present invention, among which the retardation film of the present invention is λ / It preferably has properties as a four plate or a λ / 2 plate.
Here, “having the properties as a λ / 4 plate” usually means that the absolute value of the retardation film Re of the present invention indicates a value of ¼ of the wavelength of incident light. In particular, the retardation film of the present invention preferably has an absolute value of Re in the range of 120 nm to 150 nm at a wavelength of 550 nm.
Further, the above “having properties as a λ / 2 plate” usually means that the absolute value of Re of the retardation film of the present invention shows a value half of the wavelength of incident light. In particular, the retardation film of the present invention preferably has an absolute value of Re in the range of 250 nm to 300 nm at a wavelength of 550 nm.
The definition of Re and the measurement method are the same as those described in the section “A. Polymer laminate”, and thus the description thereof is omitted here.

  The Re wavelength dispersion of the retardation film of the present invention may be a reverse dispersion type in which the Re value decreases as the wavelength becomes shorter, or a positive dispersion type in which the Re value increases as the wavelength becomes shorter. Alternatively, a flat type in which the Re value does not have wavelength dependency may be used.

  The form of the retardation film of the present invention is not particularly limited, and may be, for example, a sheet shape that matches the screen size of a liquid crystal display device using the retardation film of the present invention, or a long shape. There may be.

5. Production method of retardation film The production method of the retardation film of the present invention is not particularly limited as long as it can produce the retardation film having the above-described configuration. As such a method, a method is generally used in which the polymer laminate of the present invention is used, and an alignment layer and a retardation layer are laminated in this order on the adhesion functional layer of the polymer laminate. As a method of laminating the alignment layer and the retardation layer, generally known methods can be used.

6). Uses of Retardation Film Examples of uses of the retardation film of the present invention include an optical compensation film (for example, a viewing angle compensation film), an elliptically polarizing plate, and a brightness enhancement plate used in a liquid crystal display device. Among these, the retardation film of the present invention can be suitably used as an optical compensation film for improving the viewing angle dependency of a liquid crystal display device.

C. Next, a method for producing the polymer laminate of the present invention will be described. The method for producing a polymer laminate of the present invention uses a transparent substrate made of a cycloolefin resin, and applies an adhesive functional layer-forming coating solution containing a polymerizable monomer on the transparent substrate. After forming the forming layer, the method has an adhesion functional layer forming step of forming an adhesion functional layer by polymerizing the polymerizable monomer, and the polymerizable monomer is represented by the following formulas (I) and (II): , (III), (IV), and (V) having at least one polymerizable functional group selected from the group consisting of the polymerizable monomers, Provided is a method for producing a polymer laminate, wherein a value (N / M) obtained by dividing the monomer by the number M of elements other than carbon and hydrogen is 3 or more.

A method for producing such a polymer laminate of the present invention will be described with reference to the drawings. FIG. 3 is a schematic view showing an example of the polymer laminate of the present invention. As illustrated in FIG. 3, the method for producing a polymer laminate of the present invention uses a transparent substrate 1 made of a cycloolefin resin (FIG. 3A), and contains a polymerizable monomer on the transparent substrate 1. After the adhesion functional layer forming layer 2 ′ is formed by applying the adhesion functional layer forming coating liquid (FIG. 3B), the adhesion functional layer forming layer 2 ′ is irradiated with ultraviolet rays, and the polymerization is performed. The adhesion functional layer forming step of forming the adhesion functional layer 2 on the transparent substrate 1 by forming the adhesion functional layer forming layer 2 ′ into the adhesion functional layer 2 by polymerizing the adhesive monomer ( FIG. 3 (c)).
In such an example, the method for producing the polymer laminate of the present invention is such that the polymerizable monomer contained in the coating solution for forming an adhesion functional layer has the above formulas (I), (II), (III), Carbon having N at least one polymerizable functional group selected from the group consisting of (IV) and (V), and N constituting the polymerizable monomer is carbon constituting the polymerizable monomer. And the value (N / M) divided by the number M of elements other than hydrogen is 3 or more.
Here, in the above formulas (I), (II), (III), (IV) and (V), R ¹ , R ² and R ³ represent a methyl group or hydrogen. R ⁴ represents hydrogen, a methyl group or an ethyl group.

According to the present invention, the adhesion functional layer forming step uses a coating liquid for forming an adhesion functional layer containing a polymerizable monomer having the structure described above, on the transparent substrate made of the cycloolefin resin. By forming this, it is possible to form an adhesion functional layer having excellent adhesion to the transparent substrate.
The reason why an adhesive functional layer excellent in adhesiveness to a transparent substrate can be formed by using the adhesive monomer containing the polymerizable monomer as a coating liquid for forming an adhesive functional layer is as follows. it is conceivable that.
That is, when the carbon content ratio of the polymerizable monomer is within the above range, the polarity of the polymerizable monomer and the polarity of the cycloolefin resin constituting the transparent substrate can be approximated. For this reason, when the coating liquid for forming an adhesion function containing the polymerizable monomer is applied onto the transparent substrate, the polymerizable monomer penetrates the surface of the transparent substrate, and the polymerizable monomer is cured in this state. It is considered that the adhesive force between the adhesion functional layer and the transparent substrate can be improved.
For this reason, according to the present invention, a transparent substrate made of a cycloolefin resin is used, and a polymer laminate having excellent adhesion can be produced.

The manufacturing method of the polymer laminated body of this invention has the said contact | adherence functional layer formation process.
Hereinafter, such an adhesion functional layer forming step will be described in detail.

In the adhesion functional layer forming step in the present invention, a transparent substrate made of a cycloolefin resin is used, and an adhesion functional layer forming coating solution containing a polymerizable monomer is applied onto the transparent substrate. It can be divided into a layer forming step for forming an adhesion functional layer for forming a layer and a curing treatment step for forming an adhesion functional layer by polymerizing the polymerizable monomer.
Hereinafter, each of the adhesion functional layer forming layer forming step and the curing treatment step will be described separately.

1. First, the layer forming step for forming the adhesion functional layer will be described. This step is a step of forming an adhesion functional layer forming layer by applying a coating solution for forming an adhesion functional layer containing the polymerizable monomer on the transparent substrate using a transparent substrate made of a cycloolefin resin. is there.

  The adhesion functional layer forming coating solution used in this step contains the polymerizable monomer and the solvent, and the carbon content ratio in the polymerizable monomer is within the above range. . Here, since the polymerizable monomer used in this step is the same as that described in the above section “A. Polymer laminate”, the description thereof is omitted here.

  As content of the said polymerizable monomer contained in solid content of the said coating liquid for adhesion function layer formation, according to the use etc. of the polymer laminated body manufactured by this invention, an adhesion function layer, a transparent substrate, There is no particular limitation as long as the adhesive strength is within a desired range. Especially in this process, it is preferable to exist in the range of 1 weight%-50 weight%, and it is preferable that it exists in the range of 5 weight%-30 weight% especially.

  The solvent used in the adhesive functional layer forming coating solution is not particularly limited as long as it can dissolve the polymerizable monomer at a desired concentration. Examples of such solvents include hydrocarbon solvents such as benzene and hexane, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, ether solvents such as tetrahydrofuran and 1,2-dimethoxyethane, chloroform, dichloromethane, and the like. Alkyl halide solvents, ester solvents such as methyl acetate, ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, amide solvents such as N, N-dimethylformamide, sulfoxide solvents such as dimethyl sulfoxide, cyclohexane, etc. Examples thereof include alcohol solvents such as methanol solvents, ethanol, and propanol. In addition, the solvent used in this step may be one kind or a mixed solvent of two or more kinds of solvents.

  In addition to the polymerizable monomer, the adhesion functional layer forming coating solution used in this step may contain other compounds. Other compounds that can be used in this step are not particularly limited, and can be appropriately selected and used depending on the function imparted to the adhesion functional layer formed on the transparent substrate according to the present invention. . Such other compounds are the same as those described in the above section “A. Polymer laminate”, and thus the description thereof is omitted here.

  The coating method for coating the adhesion functional layer forming coating solution on the transparent substrate is not particularly limited as long as the desired planarity can be achieved. Examples of such coating methods include gravure coating, reverse coating, knife coating, dip coating, spray coating, air knife coating, roll coating, printing, curtain coating, die coating, and casting. Method, bar coating method, extrusion coating method, E-type coating method and the like.

  As a method for drying the coating film of the adhesion functional layer forming coating liquid, a commonly used drying method such as a heat drying method, a vacuum drying method, a gap drying method, or the like can be used. Further, the drying method in this step is not limited to a single method, and a plurality of drying methods may be employed, for example, by changing the drying method sequentially according to the amount of remaining solvent.

2. Curing process Next, the curing process will be described. In this step, the adhesive functional layer forming layer is cured by polymerizing a polymerizable monomer contained in the adhesive functional layer forming layer formed on the transparent substrate by the adhesive functional layer forming layer forming step, This is a process for forming an adhesion functional layer.

  In this step, the method for polymerizing the polymerizable monomer is not particularly limited as long as it is a method capable of inducing a polymerization reaction of the polymerizable functional group represented by the formula (1). A method of irradiating the adhesion functional layer forming layer with ultraviolet rays is used.

  The ultraviolet rays preferably have a wavelength in the range of 150 nm to 500 nm, and more preferably in the range of 250 nm to 450 nm.

3. Polymer laminate The polymer laminate produced according to the present invention has a structure in which an adhesion functional layer is formed on a transparent substrate and the transparent substrate, and a polymer of the polymerizable monomer is formed on the adhesion functional layer. It will be contained. Such a polymer laminate is the same as that described in the above-mentioned section “A. Polymer laminate”, and thus the description thereof is omitted here.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. Are included in the technical scope.

  Next, the present invention will be described more specifically by showing examples.

(1) Example 1
Use of tricyclodecane dimethanol diacrylate (carbon content ratio = 4.5) as a polymerizable monomer, dissolving the polymerizable monomer in MEK so as to have a solid content of 40%, and further adding an initiator to form an adhesive function The coating liquid is coated on a transparent substrate made of norbornene resin (trade name: Arton, manufactured by JSR), dried for 2 minutes with warm air at 80 ° C., and cured with UV of 120 mJ / cm ^2. An adhesion functional layer was formed so as to have a thickness of 6 μm.

Next, after the polymerizable liquid crystal is dissolved in the toluene solution so as to have a solid content of 20%, a coating solution for forming a retardation layer to which a polymerization initiator and a leveling agent are further added is applied on the adhesion functional layer. And dried with warm air of 60 ° C. for 2 minutes. Further, the film was cured with UV of 100 mJ / cm ² to form a retardation layer having a thickness of 1 μm on the adhesion functional layer, thereby producing a retardation film.

(2) Example 2
A retardation film was produced in the same manner as in Example 1 except that 1,6-hexanediol diacrylate (carbon content ratio = 3) was used as the polymerizable monomer.

(3) Example 3
As the polymerizable monomer, 20 parts by weight of 1,9-nonanediol diacrylate (carbon content ratio = 3.75) was mixed with 100 parts by weight of caprolactone-modified urethane acrylate (carbon content ratio <3). Except for this, an adhesion functional layer was formed by the same method as in Example 1. Here, caprolactone-modified urethane acrylate was used for the purpose of imparting a stress relaxation function to the adhesion functional layer.

  Next, an alignment layer forming coating solution in which a photo-alignment film material containing a polymer having a cinnamoyl group is dissolved in cyclohexanone so as to be 1% by weight is formed on the adhesion functional layer so as to have a thickness of 100 nm. Formed.

  Next, a retardation film was produced by forming a retardation layer on the alignment layer by the same method as in Example 1.

(4) Example 4
As the polymerizable monomer, a mixture of 30 parts by weight of tricyclodecane dimethanol diacrylate (carbon content ratio = 4.5) to 100 parts by weight of pentaerythritol triacrylate (carbon content ratio = 1.86) was used. A retardation film was produced in the same manner as in Example 1 except that.
Here, the pentaerythritol triacrylate was used for the purpose of imparting orientation to the adhesion functional layer.

(5) Comparative Example 1
A retardation film was produced in the same manner as in Example 1 except that pentaerythritol triacrylate (carbon content ratio = 1.86) was used as the polymerizable monomer.

(6) Comparative Example 2
A retardation film was produced in the same manner as in Example 1 except that neopentyl glycol diacrylate (carbon content ratio = 1.86) was used as the polymerizable monomer.

(7) Evaluation Liquid crystal orientation evaluation and adhesiveness evaluation were performed about the retardation film produced in the said Example and comparative example. In the liquid crystal orientation evaluation, a retardation film is disposed between two polarizing plates arranged in crossed Nicols, white light is irradiated from one of the polarizing plates, and light leakage is evaluated visually from the other polarizing plate side. It was carried out by doing.
In addition, the above-mentioned adhesion evaluation is performed by placing 1 mm square cuts in a grid pattern and attaching an adhesive tape (product name: cello tape (registered trademark)) manufactured by Nichiban Co., Ltd. to the surface of the phase difference layer, and thereafter adhesive tape. Was peeled off and visually observed. At this time, the evaluation was performed based on the number of cells in the portion where the adhesion was not peeled / the number of cells in the region where the tape was attached.

It is a schematic sectional drawing which shows an example of the polymer laminated body of this invention. It is the schematic which shows an example of the retardation film of this invention. It is a harm schematic showing other examples of phase contrast film of the present invention. It is the schematic which shows a part of common liquid crystal display device typically.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Transparent substrate 2 ... Adhesion functional layer 2 '... Adhesion functional layer formation layer 3 ... Retardation layer 10 ... Polymer laminated body 20 ... Retardation film

Claims (3)

A polymer laminate having a transparent substrate made of a cycloolefin-based resin and an adhesion functional layer formed so as to be in contact with the transparent substrate and containing a polymer of a polymerizable monomer and a photo-alignment material ,
The polymerizable monomer has at least one polymerizable functional group selected from the group consisting of the following formulas (I), (II), (III), (IV), and (V); and The value (N / M) obtained by dividing the number of carbon atoms constituting the polymerizable monomer by the number of elements M other than carbon and hydrogen constituting the polymerizable monomer is in the range of 3 to 5 ,
The content of the adhesion functional layer of the polymer of the polymerizable monomers, characterized in der Rukoto 17% or more, the polymer laminate.

(In the above formula, R ¹ , R ² and R ³ represent a methyl group or hydrogen. R ⁴ represents a hydrogen, methyl group or ethyl group.) A retardation film containing a liquid crystal material is formed on the adhesion functional layer of the polymer laminate according to claim 1. After forming the adhesion functional layer forming layer by applying a coating liquid for forming an adhesion functional layer containing a polymerizable monomer and a photo-alignment material on the transparent substrate using a transparent substrate made of a cycloolefin-based resin, A method for producing a polymer laminate having an adhesion functional layer forming step of forming an adhesion functional layer by polymerizing the polymerizable monomer,
The polymerizable monomer has at least one polymerizable functional group selected from the group consisting of the following formulas (I), (II), (III), (IV), and (V); and The value (N / M) obtained by dividing the number of carbon atoms constituting the polymerizable monomer by the number of elements M other than carbon and hydrogen constituting the polymerizable monomer is in the range of 3 to 5,
The process for producing a polymer laminate in which the content of solids in the polymerizable said adhesion functional layer forming coating solution of the monomer is characterized der Rukoto more than 17%.

(In the above formula, R ¹ , R ² and R ³ represent a methyl group or hydrogen. R ⁴ represents a hydrogen, methyl group or ethyl group.)

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