JP3366154B2 - Method for producing liquid crystalline polymer film - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a liquid crystalline polymer film useful for various optical elements. The present invention also relates to a method for manufacturing an optical element having a liquid crystalline polymer film.

[0002]

2. Description of the Related Art An optical element made of a liquid crystalline polymer, in particular, a liquid crystalline polymer in which a twisted nematic structure is oriented and fixed is known as a color compensating plate for a liquid crystal display device, a viewing angle compensating plate for a liquid crystal display device, an optical rotatory optical device. As an optical element such as, it shows epoch-making performance and contributes to high performance and light weight of the display device.

As a method for producing this optical element, a method has been proposed in which a layer made of a liquid crystalline polymer formed on an alignment substrate is transferred onto a transparent substrate (Japanese Patent Laid-Open No. 4-57017).
No. Hei 4-177216). Since it has become possible to separate the roles of the alignment substrate and the translucent substrate by such a manufacturing method, it has opened the way to various optical elements made of film-type polymer liquid crystals. Usually, this film type optical element is a film with a polymer liquid crystal layer that is a thin film and does not have self-supporting properties, so it is supplied as a supporting film in the form of being transferred and fixed to a plastic film that is a translucent substrate for use Be served. For example, a liquid crystalline polymer used as a color compensating plate for a super twisted nematic (STN) liquid crystal display device is transferred to a film having optical isotropy, which functions as both a transparent substrate and a supporting film,
Manufactured and supplied in a fixed form, the liquid crystal polymer exhibits excellent optical performance.

On the other hand, the requirements for the reliability of these optical elements such as compensating plates for liquid crystal display elements are very strict, and it is required to endure a severe durability test. One of the particularly severe tests of various durability tests is a long-term high temperature and high humidity test. An optical element such as a compensator for a liquid crystal display element of a film type in which a liquid crystalline polymer film layer is transferred onto a supporting substrate film (plastic film) is
Even if the liquid crystalline polymer can withstand a long-term high-temperature and high-humidity environment that is more severe than the normal conditions, the substrate film itself may not withstand depending on the type of the supporting substrate film. As a result, the reliability may be impaired as a result. In addition to these problems, depending on the type of the supporting substrate film, there are also problems such as deterioration of optical performance due to residual birefringence of the supporting substrate film itself, and deterioration of strength characteristics due to mechanical characteristics of the supporting substrate film itself. It happened. That is, when these inconveniences occur, they are often caused by the supporting substrate film used rather than the liquid crystalline polymer itself. From such a viewpoint, it has been strongly desired to realize an optical element including a liquid crystalline polymer film layer without using a supporting substrate film. Furthermore, if these optical elements can be realized, it is expected that not only reliability, but also further weight reduction and thickness reduction will be possible as compared with conventional ones.

[0005]

DISCLOSURE OF THE INVENTION It is difficult for the present inventor to have a self-supporting property when the liquid crystalline polymer is in the form of a thin film, and therefore, the liquid crystalline polymer layer formed on the alignment substrate is required. An optical element manufactured by transferring onto a plastic film having both functions of a transparent substrate and a supporting substrate film is used as it is, that is, an optical element composed of a liquid crystalline polymer layer with a supporting plastic film is formed. We paid attention to the fact that the above-mentioned problems are caused by being mounted on various liquid crystal display elements and optical devices such as polarizing plates as they are. That is, the optical function of the optical element is possessed by the liquid crystalline polymer itself, and the translucent substrate used for transfer and the plastic film as the supporting substrate function as a supporting film for the liquid crystalline polymer layer. It is nothing more than a thing.

The inventors of the present invention do not mount an optical element composed of a liquid crystalline polymer layer with a supporting plastic film on various optical devices as they are, but use some method to remove the supporting plastic film. Based on the idea that if a polymer layer can be attached to various optical elements, the optical performance and durability of the optical element will be improved, and further, weight reduction and thinning can be achieved at the same time.
As a result of intensive studies, the present invention has finally been reached.

[0007]

[Means for Solving the Problems] That is, according to the present invention, firstly, a film-like layer made of a liquid crystalline polymer oriented and formed on an oriented substrate and a releasable substrate via a curable adhesive. After adhering, the curable adhesive is cured, then the alignment substrate is peeled off to transfer the liquid crystalline polymer film-like layer to the releasable substrate, and then the cured adhesive layer is formed. The present invention relates to a method for producing a liquid crystalline polymer film, characterized in that the removable substrate is peeled off.

Secondly, according to the present invention, a film-like layer made of a liquid crystalline polymer oriented on an alignment substrate is adhered to a removable substrate via a curable adhesive. After that, the curing type
The adhesive is cured, then the alignment substrate is peeled off, and the liquid crystalline polymer film-like layer is transferred to the releasable substrate.
The present invention relates to a method for manufacturing an optical element, which comprises peeling a removable substrate while leaving a cured adhesive layer .

Thirdly, according to the present invention, a film-like layer made of a liquid crystalline polymer oriented on an orientation substrate is adhered to a releasable substrate via a curable adhesive. After that, the curing type
The adhesive is cured, then the alignment substrate is peeled off, the liquid crystalline polymer film-like layer is transferred to the releasable substrate, and then the adhesive is applied to the side opposite to the releasable substrate side of the liquid crystalline polymer film-like layer. after it allowed adhering a light-transmitting substrate through a cured adhesive
The present invention relates to a method for producing an optical element having a liquid crystalline photo-molecular film-like layer, characterized in that the removable substrate is peeled off leaving the agent layer .

Fourthly, the present invention is characterized in that the liquid crystalline polymer is a nematic alignment or a twisted nematic alignment in a liquid crystal state, and becomes a glass state at a temperature below a liquid crystal transition point. The present invention relates to a method for manufacturing the optical element.

The present invention will be described in detail below. The alignment substrate that can be used in the present invention has the ability to align a liquid crystalline polymer into a desired structure and heat resistance and solvent resistance within a range that does not impair the object of the present invention. It is not particularly limited as long as it has a peeling property capable of peeling at the interface with the polymer. As a typical example of such an oriented substrate, first, a metal substrate of aluminum, iron, copper or the like or a sheet-shaped or plate-shaped substrate of glass or the like is rubbed with a polyimide film, a rubbed polyvinyl alcohol film or silicon oxide. Examples of the film having an oriented thin film such as the obliquely vapor-deposited film. In addition, as another example, polyimide, polyamide-imide, polyamide, polyether imide, orie ether ate ketone,
For polyether ketone, polyketone sulfide, polyether sulfone, polysulfone, polyphenylene sulfide, polyphenylene oxide, polyethylene terephthalate, polybutylene terephthalate, polyacetal, polycarbonate, acrylic resin, polyvinyl alcohol, cellulosic plastics, epoxy resin, phenol resin, etc. Examples of the plastic film or sheet include the substrates whose surfaces are directly rubbed, the polyimide films rubbed on these films or sheets, the rubbed polyvinyl alcohol films, and the substrates having oriented thin films. In addition, of these plastic films or plastic sheets, those with high crystallinity are 1
Some of them have a liquid crystal polymer alignment ability only by axially stretching, and those can be used as an alignment substrate directly by rubbing treatment or as they are. Specific examples of such plastics include polyimide, polyetherimide, polyetheretherketone, polyetherketone, polyphenylene sulfide, and polyethylene terephthalate.

As the alignment substrate, one having a property of easily peeling from the liquid crystalline polymer, preferably substantially non-adhesive, is practically preferable. From such a viewpoint and alignment ability, a glass or metal plate is particularly preferable. An oriented substrate having a rubbed polyimide film or a rubbed polyvinyl alcohol film thereon, or an oriented substrate obtained by directly rubbing a film or sheet of polyimide, polyethylene terephthalate, polyphenylene sulfide, polyether ether ketone, polyvinyl alcohol or the like is preferable.

The type of the liquid crystalline polymer used in the present invention is not limited as long as it does not impair the object of the present invention, and examples thereof include thermotropic liquid crystalline polymers and lyotropic liquid crystalline polymers. Is preferred. In addition, the alignment structure of the liquid crystalline polymer can be preferably exemplified by nematic alignment and twisted nematic alignment. When used in an optical element, it is desirable that the liquid crystalline polymer has the following properties. That is, a liquid crystalline polymer that exhibits uniform and monodomain nematic or twisted nematic alignment and that can easily fix the alignment state is preferable. It is desirable to use a liquid crystalline polymer that can be immobilized without impairing the alignment in the liquid crystal state by heat treatment to form a uniform monodomain nematic or twisted nematic structure and then cooling. For this purpose, it is desirable to further have the following properties. In order to carry out stable immobilization of nematic or twisted nematic orientation, it is particularly preferable that the crystal phase does not have a crystal phase at a temperature lower than that of the nematic or twisted nematic phase in view of the liquid crystal phase series. When the crystalline phase is present, when it is cooled for immobilization, it necessarily passes through the crystalline phase, and as a result, the once obtained twisted nematic orientation is destroyed. Therefore, it is desirable that the liquid crystalline polymer used for the optical element not only has a good orientation due to the interfacial effect but also becomes a glass state at a temperature lower than the nematic or twisted nematic phase, that is, below the liquid crystal transition point.

A preferred liquid crystalline polymer having a twisted nematic orientation is a liquid crystalline polymer having a uniform and mono-domain nematic orientation and capable of easily fixing its orientation state in a predetermined amount of an optically active compound. And a liquid crystalline polymer which itself exhibits a uniform and monodomain twisted nematic orientation and which can easily fix the orientation state.

First, the former composition comprising a nematic liquid crystal polymer and an optically active compound will be described. A liquid crystal polymer which shows a uniform and monodomain nematic orientation as a base and can easily fix the orientation state. Is
In order to use the liquid crystalline polymer film of the present invention as an optical element, it is desirable to use a liquid crystalline polymer having a glass phase at a temperature lower than the nematic phase. By adding an optically active compound to these polymers, a twisted nematic orientation is obtained in the liquid crystal state, and a glass phase is taken below the liquid crystal transition point, so that the twisted nematic structure can be easily fixed. As the type of polymer used, any polymer that is nematically aligned in a liquid crystal state and becomes a glass state at a liquid crystal transition point or lower can be used. For example, a main chain type liquid crystal polymer such as polyester, polyamide, polycarbonate, polyesterimide, or polyacrylate. Examples thereof include side-chain liquid crystal polymers such as polymethacrylate, polymalonate, and polysiloxane. Among them, polyester is preferable in terms of easiness of synthesis, transparency, orientation, glass transition point and the like. The polyester used is most preferably a polymer containing an ortho-substituted aromatic unit as a constituent, but an aromatic having a bulky substituent in place of the ortho-substituted aromatic unit, or a fluorine or an aromatic having a fluorine-containing substituent. Polymers containing such as as a constituent can also be used. The ortho-substituted aromatic unit referred to in the present invention means a structural unit in which the bonds forming the main chain are ortho to each other. Specific examples include catechol units, salicylic acid units, phthalic acid units and those having a substituent on the benzene ring of these groups as shown below.

[0016]

[Chemical 1]

(X represents hydrogen, halogen such as Cl or Br, an alkyl group or an alkoxy group having 1 to 4 carbon atoms, or a phenyl group. K is an integer of 0 to 2.) Among these, The following can be illustrated as a preferable example.

[0018]

[Chemical 2]

Polyesters preferably used in the present invention include (a) structural units derived from diols (hereinafter referred to as diol components) and structural units derived from dicarboxylic acids (hereinafter referred to as dicarboxylic acid components) and / or Alternatively, (b) a structural unit derived from an oxycarboxylic acid containing a carboxylic acid and a hydroxyl group at the same time in one unit (hereinafter referred to as an oxycarboxylic acid component) is contained as a constituent component, and preferably the ortho-substituted aromatic unit is included. Examples of the polymer include: Among these, examples of the diol component include the following aromatic and aliphatic diols.

[0020]

[Chemical 3]

(Y represents hydrogen, an alkyl group having 1 to 4 halogen atoms such as Cl or Br, an alkoxy group or a phenyl group. 1 is an integer of 0 to 2.)

[0022]

[Chemical 4]

Above all,

[0024]

[Chemical 5]

And the like are preferably used.

The following can be exemplified as the dicarboxylic acid component.

[0027]

[Chemical 6]

(Z represents hydrogen, halogen such as Cl and Br, an alkyl group or an alkoxy group having 1 to 4 carbon atoms, or a phenyl group. M is an integer of 0 to 2),

[0029]

[Chemical 7]

Above all,

[0031]

[Chemical 8]

And the like are preferred.

Specific examples of the oxycarboxylic acid component include the following units.

[0034]

[Chemical 9]

The molar ratio of the dicarboxylic acid to the diol is approximately 1: 1 as in general polyesters (the ratio of carboxylic acid groups to hydroxyl groups when using oxycarboxylic acid), and the ortho ratio in the polyester. The ratio of the substituted aromatic unit is preferably in the range of 5 mol% to 40 mol%,
More preferably, it is in the range of 10 mol% to 35 mol%. When it is less than 5 mol%, a crystal phase tends to appear below the nematic phase, which is not preferable. 40 mol%
When the amount is larger, the polymer tends to lose liquid crystallinity, which is not preferable. The following polymers can be illustrated as a typical polyester.

[0036]

[Chemical 10]

[0037]

[Chemical 11]

[0038]

[Chemical 12]

Polymers having an aromatic unit containing a bulky substituent as shown below instead of an ortho-substituted aromatic unit, or a polymer containing an aromatic unit containing a fluorine- or fluorine-containing substituent as a constituent component are also preferably used.

[0040]

[Chemical 13]

[0041]

[Chemical 14]

The molecular weight of these polymers can be determined in various solvents such as phenol / tetrachloroethane (60/40).
(Weight ratio) The logarithmic viscosity measured at 30 ° C. in the mixed solvent is 0.
05 to 3.0 is preferable, and 0.0 is more preferable.
It is in the range of 7 to 2.0. When the logarithmic viscosity is less than 0.05, the strength of the obtained liquid crystalline polymer may be weakened, which is not preferable. On the other hand, when it is more than 3.0, the viscosity at the time of liquid crystal formation is too high, which may cause problems such as deterioration of alignment property and increase of time required for alignment. Further, the glass transition point of these polyesters is also important and affects the stability of orientation after the orientation is fixed. Although it depends on the application, it is generally desirable that the glass transition point is 0 ° C. or higher, considering that the glass transition temperature is around room temperature.
It is desirable that the temperature is ℃ or higher.

The method of synthesizing these polymers is not particularly limited, and they can be synthesized by a polymerization method known in the art, for example, a melt polymerization method or an acid chloride method using a corresponding dicarboxylic acid chloride. In the case of synthesizing by a melt polymerization method, it can be produced, for example, by polymerizing an acetylated product of a corresponding dicarboxylic acid and a corresponding diol at high temperature under high vacuum, and the molecular weight can be easily controlled by controlling the polymerization time or controlling the charging composition. .
In order to accelerate the polymerization reaction, a conventionally known metal salt such as sodium acetate can be used. When the solution polymerization method is used, a desired amount of dicarboxylic acid dichloride and diol are dissolved in a solvent and heated in the presence of an acid acceptor such as pyridine to easily obtain the target polyester.

The optically active compound which is mixed to impart twist to these nematic liquid crystalline polymers will be described. First, a representative example is an optically active low molecular weight compound. Any compound having optical activity can be used in the present invention, but an optically active liquid crystal compound is preferable from the viewpoint of compatibility with the base polymer. Specifically, the following compounds can be exemplified.

[0045]

[Chemical 15]

[0046]

[Chemical 16]

Examples of the optically active compound used in the present invention include the optically active polymer compounds. Any polymer compound having an optically active group in the molecule can be used, but a polymer compound having liquid crystallinity is preferable from the viewpoint of compatibility with the base polymer. Examples thereof include liquid crystalline polyacrylates, polymethacrylates, polymalonates, polysiloxanes, polyesters, polyamides, polyesteramides, polycarbonates having an optically active group, polypeptides, celluloses and the like. Among them, an optically active polyester mainly containing an aromatic compound is most preferable because of its compatibility with the nematic liquid crystal polymer as the base. Specifically, the following polymers can be exemplified.

[0048]

[Chemical 17]

[0049]

[Chemical 18]

[0050]

[Chemical 19]

[0051]

[Chemical 20]

[0052]

[Chemical 21]

The proportion of the optically active group in these polymers is usually 0.5 mol% to 80 mol%, preferably 5 mol% to 60 mol%. The molecular weight of these polymers is preferably in the range of 0.05 to 5.0 in logarithmic viscosity measured at 30 ° C. in phenol / tetrachloroethane. When the logarithmic viscosity is more than 5.0, the viscosity is too high, which may result in deterioration of orientation, which is not preferable, and when it is less than 0.05, the composition is difficult to control, which is not preferable.

These compositions can be prepared by a method such as solid mixing, solution mixing or melt mixing of the nematic liquid crystalline polyester and the optically active compound in a predetermined ratio. The ratio of the optically active compound in the composition varies depending on the ratio of the optically active group in the optically active compound or the twisting force when the nematic liquid crystal of the optically active compound is twisted, but it is generally 0. 1 to 60
The range of wt% is preferable, and the range of 0.5 to 40 wt% is particularly preferable. If it is less than 0.1 wt%, the nematic liquid crystal may not be sufficiently twisted, and if it is more than 60 wt%, the orientation may be adversely affected.

The liquid crystalline polymer film of the present invention, in particular, the optical element can also have a uniform and monodomain twisted nematic orientation by itself and easily fix the orientation state without using other optically active compounds. It can also be produced by using a liquid crystalline polymer. It is essential that these polymers have an optically active group in the main chain and are themselves optically active. Specifically, the main chain type liquid crystal polymer such as optically active polyester, polyamide, polycarbonate, polyesterimide, or Examples thereof include side chain type liquid crystal polymers such as polyacrylate, polymethacrylate, and polysiloxane. Among them, polyester is preferable from the viewpoint of easiness of synthesis, orientation, glass transition point and the like. The polyester used is most preferably a polymer containing an ortho-substituted aromatic unit as a constituent, but an aromatic having a bulky substituent in place of the ortho-substituted aromatic unit, or an aromatic having a fluorine- or fluorine-containing substituent, etc. Polymers containing as a constituent can also be used. These optically active polyesters can be obtained by introducing the following optically active groups into the nematic liquid crystalline polyesters described so far using an optically active diol, dicarboxylic acid or oxycarboxylic acid. (In the formula, * indicates optically active carbon)

[0056]

[Chemical formula 22]

[0057]

[Chemical formula 23]

The proportion of these optically active groups in the polymer is preferably from 0.1 to 50 mol%, particularly preferably from 0.5 to 30 mol%. If the proportion of the optically active group is less than 0.1%, the twisted structure required for the compensator may not be obtained, and if it exceeds 50 mol%, the orientation may be deteriorated, which is not preferable. The molecular weight of these polymers is such that the logarithmic viscosity measured at 30 ° C. in various solvents such as a mixed solvent of phenol / tetrachloroethane (60/40) is 0.05 to 3.0.
Is preferable, and more preferably in the range of 0.07 to 2.0. When the logarithmic viscosity is less than 0.05, the strength of the obtained polymer liquid crystal may be weak, which is not preferable. On the other hand, when it is more than 3.0, the viscosity at the time of forming the liquid crystal is too high, which may cause problems such as deterioration of alignment property and increase of time required for alignment. Further, the glass transition point of these polyesters is also important and affects the stability of orientation after the orientation is fixed. Although it depends on the application, it is generally desirable that the glass transition point be 0 ° C. or higher, particularly 20 ° C. or higher, considering that the glass transition point is to be used near room temperature.

Polymerization of these polymers can be carried out by using the above-mentioned melt polycondensation method or the acid Croyde method. As typical examples of the liquid crystalline polymer of the present invention described above, specifically,

[0060]

[Chemical formula 24]

Polymer represented by Ch: cholesteryl group (m / n = normally 99.9 / 0.1 to 70/30, preferably 99.5 / 0.5 to 80/20, more preferably 99/1 ~ 90/10)

[0062]

[Chemical 25]

Polymer represented by (m / n = usually 99.
9 / 0.1-70 / 30, preferably 99.5 / 0.5
~ 80/20, more preferably 99/1 to 90/1
0)

[0064]

[Chemical formula 26]

The polymer represented by (m / n = usually 99.
9 / 0.1-70 / 30, preferably 99.5 / 0.5
~ 90/10, more preferably 99/1 to 95/5,
p, q; integer of 2 to 20)

[0066]

[Chemical 27]

The polymer represented by (m / n = normally 99.
9 / 0.1-70 / 30, preferably 99.5 / 0.5
~ 90/10, more preferably 99/1 to 95/5,
p, q; integer of 2 to 20)

[0068]

[Chemical 28]

Polymer represented by (m / n = usually 99.
9 / 0.1-60 / 40, preferably 99.5 / 0.5
~ 80/20, more preferably 99/1 to 90/1
0)

[0070]

[Chemical 29]

Polymer (m / n = 0.5 / 9)
9.5-30 / 70, preferably 1 / 99-10 / 9
0)

[0072]

[Chemical 30]

The polymer represented by (k = 1 + m + n, k
/N=99.5/0.5 to 60/40, preferably 9
9 / 1-70 / 30, 1 / m = 5 / 95-80 / 20)

[0074]

[Chemical 31]

The polymer represented by (k = 1 + m + n, k
/N=99.5/0.5 to 60/40, preferably 9
9 / 1-70 / 30, 1 / m = 5 / 95-80 / 20)

[0076]

[Chemical 32]

Polymer mixture represented by ((A) /
(B) = usually 99.9 / 0.1 to 50/50 (weight ratio), preferably 99.5 / 0.5 to 70/30, more preferably 99/1 to 80/20, k = 1 + m, 1 /
m = 75/25 to 25/75, p = q + r, p / q = 8
0/20 to 20/80)

[0078]

[Chemical 33]

(B) Polymer mixture represented by cholesteryl benzoate ((A) / (B) = normally 9
9.9 / 0.1-50 / 50 weight ratio, preferably 99.
5 / 0.5 to 70/30, more preferably 99/1 to
80/20, m = k + 1, k / 1 = 80/20 to 20 /
80)

[0080]

[Chemical 34]

Polymer mixture represented by ((A) /
(B) = usually 99.9 / 0.1-60 / 40 (weight ratio)
Preferably 99.5 / 0.5 to 70/30, preferably 99/1 to 80/20, k = 1 + m, 1 / m = 25/7
5 to 75/25, p = q + r, q / r = 20/80 to 8
0/20)

Next, the adhesive used in the present invention will be described. In the present invention, as an adhesive that can be used in adhering the film-like layer of the liquid crystalline polymer and the releasable substrate, it is possible to adhere to both the liquid crystalline polymer film layer and the releasable substrate. There is no particular limitation as long as it has the property of peeling from the peelable substrate, and it is appropriately selected depending on the liquid crystalline polymer and the releasable substrate to be used. Further, when a liquid crystalline polymer film is used as an optical element in the present invention, it is desirable that the adhesive used has optical isotropy. As such an adhesive, for example, a photo-curing type, an electron beam-curing type, or a thermosetting type adhesive is preferable, and among them, a photo-curing type or electron beam-curing type containing an acrylic oligomer as a main component or an epoxy A resin-based photocurable type or electron beam curable type is desirable. When a liquid crystalline polymer film is used for an optical element, it is preferable to use a liquid crystalline polymer that becomes a glass state at a temperature below the liquid crystal transition point as described above, but an acrylic oligomer as a main component as an adhesive. By using a photo-curable or electron beam-curable type, or an epoxy resin-based photo-curable type or electron beam-curable type, the liquid crystal polymer has a liquid crystal transition temperature below the necessary for maintaining its optical function. It is possible to obtain the effect that the curing and adhesion treatment in step 1 can be performed, and the high-speed treatment required in continuous treatment can be performed.

The form of adhesion between the liquid crystalline polymer film layer and the removable substrate is not particularly limited, but a layered adhesive layer is provided between the liquid crystalline polymer film layer and the removable substrate. Is common. The thickness of the adhesive layer is not particularly limited, but is usually 0.1 μ to 100 μ, preferably about 1 μ to 30 μ. Further, if necessary, various additives such as an antioxidant and an ultraviolet absorber may be added to the adhesive as long as the object of the present invention is not impaired.

The releasable substrate used in the present invention is not particularly limited as long as it is a substrate having removability and self-supporting property, and a plastic film having releasability is usually used as the substrate. desirable. The removability as referred to in the present invention means that in the state where the liquid crystalline polymer film layer and the releasable substrate are bonded via an adhesive, it can be peeled at the interface between the adhesive and the removable substrate, preferably , After the air side surface of the liquid crystalline polymer film-like layer transferred onto the removable substrate via the adhesive and the translucent substrate prepared separately are opposed to each other and bonded to each other via the adhesive or the adhesive, It is desirable that the releasable substrate can be peeled at the interface with the adhesive that is in direct contact. As the plastic film having removability used in the present invention, the value of the peel strength (180 ° peel test, peel speed 30 cm / min) at the interface with the adhesive (after curing) is usually 0.5 to 80 gf. /
The peel strength is 25 mm, preferably 2 to 50 gf / 25 mm. Specific examples of the plastic film suitable as the removable substrate include olefin resins such as polyethylene, polypropylene and 4-methylpentene-1 resin, polyamide, polyimide, polyamideimide, polyetherimide, polyetherketone,
Polyether ether ketone, polyether sulfone,
Examples thereof include polyketone sulfide, polysulfone, polystyrene, polyphenylene sulfide, polyphenylene oxide, polyethylene terephthalate, polybutylene terephthalate, polyarylate, polyacetal, polycarbonate, polyvinyl alcohol, and cellulosic plastics. These plastic films themselves may be used, or in order to have appropriate removability, the surface of these plastic films,
Those coated with silicone, those formed with an organic thin film or inorganic thin film, those subjected to chemical treatment, and those subjected to physical treatment such as corona discharge treatment can be used. In the present invention, polypropylene, polyether ether ketone, polyethylene terephthalate, polycarbonate and a plastic film obtained by subjecting the surface of these films to a silicone treatment or a corona discharge treatment,
It is desirable because it has both an adhesive property and appropriate adhesiveness and peelability.

In the method for producing a liquid crystalline polymer film of the present invention, a liquid crystalline polymer film-like layer is oriented and formed on an alignment substrate, and then the oriented liquid crystalline polymer film is formed on the alignment substrate. After adhering the layer to the releasable substrate via an adhesive, the alignment substrate is peeled off to transfer the liquid crystalline polymer film-like layer to the releasable substrate, and then the releasable substrate is peeled off. . In a further preferred embodiment, after applying the liquid crystalline polymer on the alignment substrate, heat treatment or the like is performed to form a uniform and monodomain alignment structure, and then cooling is performed without impairing the alignment in the liquid crystal state. After forming a liquid crystalline polymer film-like layer by immobilization, and then adhering the liquid crystalline polymer film-like layer oriented and formed on the alignment substrate to the releasable substrate via an adhesive layer The alignment substrate is peeled off, the liquid crystalline polymer film-like layer is transferred to the peelable substrate, and then the removable substrate is peeled off.

First, the step of aligning and forming a liquid crystalline polymer on an alignment substrate will be described. Examples of the method for forming the liquid crystalline polymer film layer on the alignment substrate include a method using a liquid crystalline polymer solution and a method using a molten liquid crystalline polymer. In the former method, the solvent for dissolving the liquid crystalline polymer and preparing the coating solution varies depending on the type of the liquid crystalline polymer used, but usually chloroform, dichloroethane, tetrachloroethane, trichloroethylene, tetrachloroethylene, orthodichlorobenzene. And the like, a mixed solvent of these with phenols, ketones, ethers, dimethylformamide, dimethylacetamide, dimethylsulfoxide, N-methylpyrrolidone, sulfolane, cyclohexane and the like polar solvents can be used. The concentration of the solvent is appropriately selected depending on the liquid crystalline polymer used, but is usually in the range of 5 to 50% by weight, preferably 10 to
A range of 30% by weight is desirable.

Next, the liquid crystal polymer solution is applied onto the alignment substrate. Examples of the coating method include a spin coating method, a roll coating method, a gravure coating method, a curtain coating method, a slot coating method and a dipping and pulling method.

After coating, the solvent is removed by drying, and heat treatment is performed at a predetermined temperature for a predetermined time to form a uniform monodomain orientation (nematic orientation, twisted nematic orientation, etc.).
Regarding the formation of the orientation, when the liquid crystalline polymer film of the present invention is used as an optical element, it is desirable to form a nematic orientation or a twisted nematic orientation. The viscosity of the liquid crystalline polymer is preferably low in order to assist the alignment due to the interfacial effect. Therefore, it is desirable that the temperature at the time of alignment is high, but if the temperature is too high, cost increases and workability deteriorates, which is not preferable. . Further, depending on the type of liquid crystalline polymer, an isotropic phase is present at a temperature higher than that of the liquid crystal phase (nematic phase, twisted nematic phase, etc.), so that orientation cannot be obtained even by heat treatment in this temperature range. As described above, according to the characteristics of the polymer, a liquid crystal having a liquid crystal transition point or more (liquid crystal transition point in the case of a liquid crystalline polymer that is in a glass state below the liquid crystal transition point = glass transition point) and below the transition point to the isotropic phase It is desirable to heat treat at a temperature that exhibits a phase, and generally,
It is arbitrarily selected from the range of 50 ° C to 300 ° C, particularly 10
The range of 0 ° C to 250 ° C is preferable.

The time required to obtain sufficient alignment in the liquid crystal state on the alignment film varies depending on the polymer composition and molecular weight and cannot be generally stated, but is usually in the range of 10 seconds to 100 minutes, and particularly 30 seconds to A range of 60 minutes is preferred. If it is shorter than 10 seconds, the orientation may be insufficient, and if it is longer than 100 minutes, the transparency of the obtained liquid crystalline polymer film may be lowered. Also, the same alignment state can be obtained by applying the liquid crystalline polymer in a molten state onto the alignment substrate and then performing heat treatment. In this way, first, a film-like layer having a uniform alignment (nematic alignment, twisted nematic alignment) over the entire surface of the alignment substrate in a liquid crystal state can be obtained.

The orientation state thus obtained is cooled,
The liquid crystalline polymer film-like layer is formed by fixing the liquid crystal state without impairing the orientation. By using a liquid crystalline polymer that is in a glass state below the liquid crystal transition point, by cooling to a temperature below the liquid crystal transition point (that is, below the glass transition point), the alignment can be achieved without impairing the alignment. In general, when a liquid crystalline polymer having a crystal phase at a temperature lower than the liquid crystal phase is used, the orientation of the liquid crystal state may be broken by cooling,
By using a liquid crystalline polymer that is in a glass state below the liquid crystal transition point, such a phenomenon can be avoided, and liquid crystal alignment such as nematic alignment or twisted nematic alignment can be completely fixed. it can.

The cooling rate is not particularly limited, and it is fixed only by exposing it from the heating atmosphere to the atmosphere below the glass transition point. In addition, forced cooling such as air cooling or water cooling may be performed in order to increase production efficiency. The thickness of the liquid crystalline polymer film-like layer after immobilization is not particularly limited, but is usually 0.
1 μm to 100 μm, preferably 0.5 μm to 50 μm
A range up to m is preferred. If the film thickness is less than 0.1 μm, the desired effect may not be obtained when used as an optical element, and if it exceeds 100 μm, it may be difficult to obtain uniform orientation.

Incidentally, in the case of orientation-fixed, for example, twisted nematic orientation, the twist angle is not particularly limited as long as it exceeds 0 degree, and it may be appropriately selected according to the purpose, but it is usually an absolute value. It is 30 degrees or more, preferably 40 degrees or more, and the upper limit is usually about 5000 degrees.

Next, the step of transferring the liquid crystalline polymer film layer oriented and formed on the oriented substrate to the removable substrate will be described. An adhesive is applied to at least one or both of the liquid crystalline polymer film-like layer surface formed as described above on the removable substrate surface and the orientation substrate, and they are bonded together.
The bonding method is not particularly limited, and any method can be used. When a curable adhesive is used, the adhesive is cured after the bonding. As the means for curing the adhesive, light curing, electron beam curing, or heat curing is adopted depending on the type of adhesive used.

After the adhesive is cured, the liquid crystalline polymer film-like layer can be transferred to the removable substrate by peeling the alignment substrate at the interface with the liquid crystalline polymer film-like layer. The method of peeling is not particularly limited, and a suitable method is selected depending on the adhesiveness between the liquid crystalline polymer film layer and the alignment substrate. For example, when the alignment substrate is a film, the alignment substrate film is usually The edge of the liquid crystalline film-like layer is grasped by hand or attached with an adhesive tape such as vinyl tape and peeled off, and the oriented substrate film is usually 90-
A method of peeling in the direction of 180 degrees, preferably approximately 180 degrees is adopted. A method of mechanically using a roll is also effective.

In this way, the liquid crystal polymer film layer in which the orientation is formed can be transferred to the removable substrate. In the present invention, a liquid crystal polymer film is thus obtained by obtaining a laminate comprising a liquid crystalline polymer film-like layer adhered to the releasable substrate via an adhesive and then peeling the releasable substrate. Is what you get. The peeling of the removable substrate can be performed by peeling the removable substrate at the interface between the removable substrate and the adhesive, usually the adhesive layer. The peeling method is not particularly limited, and a suitable method is selected according to the adhesiveness between the removable substrate and the adhesive layer. For example, when the releasable substrate is a film, the releasable substrate film is usually gripped by hand or attached with an adhesive tape such as a vinyl tape to release the releasable substrate film.
A method of peeling in the direction of 180 degrees, preferably about 180 degrees is adopted. Further, a method of mechanically using a roll is also effective. When both the liquid crystalline polymer film layer oriented on the orientation film and the releasable substrate are long films, application of adhesive, bonding, curing of adhesive, peeling of oriented substrate It is also possible to continuously perform a series of steps including the above.

Thus, the liquid crystalline polymer film is manufactured. Further, in order to protect the surface of the liquid crystalline polymer layer of the liquid crystalline polymer film, a protective layer such as a curable acrylic resin or a curable epoxy resin is provided on the liquid crystalline polymer layer, or a surface protective film is attached. You may combine.

The liquid crystalline polymer film thus produced may be used as it is for various uses such as an optical element, but it may be combined with another substrate (second substrate). In this case, the releasable substrate may be peeled off to obtain a liquid crystalline polymer film and then combined with the second substrate (usually bonding), but at the stage where the releasable substrate is not peeled off, that is, on the releasable substrate. It is desirable that the laminate including the liquid crystalline polymer film-like layer adhered to the substrate with an adhesive is directly used for the next step of adhering to the second substrate. When the liquid crystal polymer film is used as an optical element, it is desirable that the second substrate has a light transmitting property.

Examples of the translucent substrate include a plastic film or a plastic sheet having transparency and optical isotropy. Examples of the plastic include polymethylmethacrylate, polystyrene, polycarbonate, polyethersulfone, polyarylate,
Amorphous polyolefin, triacetyl cellulose, epoxy resin and the like can be mentioned, and among them, polymethyl methacrylate, polycarbonate, polyether sulfone, polyarylate, amorphous polyolefin and the like are preferable. Examples of other types of translucent substrates include glass, a polarizing plate, and upper and lower glass substrates forming a liquid crystal driving cell. The type of glass is not particularly limited, depending on the use of the optical element made of a thin liquid crystal polymer film, window glass, decorative glass,
Examples include glass for automobiles and glass for instruments. The polarizing plate is an essential optical element for a liquid crystal display,
If a polarizing plate is used as the translucent substrate, it becomes possible to make an optical element integrated with an optical element made of a thin liquid crystalline polymer film, which is extremely convenient. Further, by using a glass substrate above or below the glass substrate above or below the liquid crystal display drive cell or on both surfaces as a transparent substrate, an optical element made of a thin film liquid crystalline polymer film can be integrated, It is convenient.

In the step of bonding the second substrate, the bonding is usually performed by using a pressure sensitive adhesive or an adhesive. The pressure-sensitive adhesive used is not particularly limited as long as it has optical isotropy, but acrylic, rubber-based, silicone-based, polyvinyl acetate-based, ethylene-vinyl acetate-based, etc. can be exemplified, and are preferable. Is an acrylic adhesive. As the adhesive, any adhesive can be used as long as it has optical isotropy.
Examples thereof include photo-curing type and electron beam-curing type adhesives. Among them, a photocurable or electron beam curable adhesive containing an acrylic oligomer as a main component, or an epoxy resin photocurable or electron beam curable adhesive is preferable.

Next, the step of adhering the laminate composed of the liquid crystalline polymer film-like layer adhered to the releasable substrate with an adhesive as it is to the second substrate will be described. At least one or both of the liquid crystal polymer film layer surface and the second substrate surface on the removable substrate is coated with a pressure-sensitive adhesive or an adhesive and bonded. In a form in which a protective layer is provided to protect the surface of the liquid crystalline polymer layer, a pressure-sensitive adhesive or an adhesive is applied to at least one of the protective layer surface and the second substrate surface and then bonded. The bonding method is not particularly limited, and any method can be used, and a method suitable for the type, size, and form of the second substrate is adopted. Further, after that, the releasable substrate is peeled off by the same method as described above to obtain an element having a liquid crystalline polymer film-like layer on the second substrate. Of course, the element can also be obtained by peeling the releasable substrate to obtain a liquid crystalline polymer film and then laminating it in the same manner as the second substrate.

FIG. 1 shows an outline of typical steps in the method of manufacturing an optical element of the present invention. In FIG. 1, a releasable substrate (14) is attached via an adhesive (13) onto a liquid crystalline polymer film layer (12) oriented and formed in the orientation substrate (11). Next, the alignment substrate is peeled off at the interface between the alignment substrate and the liquid crystalline polymer film layer, and the liquid crystalline polymer layer is transferred onto the removable substrate. Next, the liquid crystal polymer film-like layer surface on the air side of the liquid crystal polymer layer transferred to the removable substrate and the second substrate (transparent substrate) (16) are opposed to each other, and the adhesive (15) Alternatively, they are bonded together via an adhesive (15). After the bonding, the releasable substrate is peeled off at the interface between the releasable substrate and the adhesive to obtain an optical element having a thin film liquid crystalline polymer film layer. Of course, the present invention is not limited to the process shown in FIG. 1 as described in detail above.

[0102]

INDUSTRIAL APPLICABILITY By the method of the present invention, a thin film liquid crystalline polymer film can be produced, the alignment structure of liquid crystal is fixed in the film, and the film is highly reliable. It can be used for a display element represented by a color compensating plate for a liquid crystal display element, a viewing angle compensating plate for a liquid crystal display element, a retardation plate, an optical rotatory optical element, etc., and an optical element used in the optical and optoelectronic fields. . Furthermore, since it has become possible to manufacture optical elements made of a liquid crystalline polymer film in the form without a supporting substrate, by combining it with various other optical elements, the optical performance such as the light transmittance of the optical element can be improved. It has high industrial value such as improved durability, lighter weight and thinner film, and excellent effects such as cost reduction.

[0103]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. The analytical methods used in the examples are as follows. (1) Determination of polymer composition The polymer was dissolved in deuterated chloroform or deuterated trifluoroacetic acid, and measured and determined by ¹ H-NMR (400 nm) of JHN-GX400 manufactured by JEOL. (2) Measurement of logarithmic viscosity Using an Ubbelohde viscometer, it was measured at 30 ° C. in a phenol / tetotachloroethane (60/40 weight ratio) mixed solvent. (3) Measurement of film thickness Digital Micrometer μ-M manufactured by Sony Corporation
It was measured by ATE (M-30).

Production Examples 1 to 3 of Polymer Liquid Crystal Layer Aligned on Alignment Substrate

[0105]

[Chemical 35]

Phenol / tetrachloroethane (60/40 weight ratio) in which the concentration of the mixed polymer represented by the formula (1) (total aromatic polymer has a logarithmic viscosity of 0.20, optically active polymer has a logarithmic viscosity of 0.14) is 18 wt%. ) A solution was prepared.
Using this solution, a long film of polyetheretherketone rubbed as an alignment substrate (thickness 100 μm
m, width 30 cm) using a roll coater, followed by drying, heat treatment at 200 ° C. for 45 minutes, and then cooling to obtain a long (1) fixed orientation of the liquid crystalline polymer layer. A 100 m long film was obtained. The twist angle of this liquid crystalline polymer film layer was −240 °, and Δn · d was 0.82 μ.
It was m.

Production Example 2

[0108]

[Chemical 36]

A tetrachloroethane solution having a concentration of 20 WT% of the mixed polymer represented by the formula (2) (total aromatic polymer logarithmic viscosity 0.15, Tg = 110 ° C., optically active polymer logarithmic viscosity 0.14) was prepared. did. Using this solution, a long polyimide film rubbed as an alignment substrate (thickness 100 μm, width 30 cm) was coated using a roll coater, dried, and heat treated at 200 ° C. for 30 minutes, and then cooled. Thus, a long film 250m in which the orientation of the liquid crystalline polymer layer of (2) was fixed was manufactured. The twist angle of this liquid crystalline polymer film layer is -89.
°, Δn · d was 2.2 μm.

Production Example 3

[0111]

[Chemical 37]

An N-methylpyrrolidone solution having a concentration of 25 WT% of the optically active polymer of the formula (3) (logarithmic viscosity 0.16, Tg = 83 ° C.) was prepared. Using this solution, a long rubbed polyethylene phthalate (thickness: 75 μm, width: 30 cm) used as an alignment substrate was coated using a gravure roll coater and then dried, and 160 ° C. × 20.
Heat treatment was performed for a minute, and then cooling was performed to obtain 100 m of a long film in which the orientation of the liquid crystalline polymer layer of (3) was fixed. The twist angle of this liquid crystalline polymer film layer is -230.
°, Δn · d was 0.84 μm.

Example 1 A film composed of the polymer liquid crystal layer of (1) oriented and formed on the polyether ether ketone film obtained in Production Example 1 was cut into a size of 20 × 30 cm, and on this polymer liquid crystal layer, Using a bar coater, a commercially available ultraviolet curable acrylic oligomer adhesive was applied to a thickness of 5 μm.
Next, the peel strength at the interface with the cured acrylic resin adhesive layer (180 ° peel test) was 2 gf / 25 mm on the coated surface.
The thickness after corona discharge treatment is 38 μm, size 25 ×
After a corona discharge treated surface side of a 35 cm polypropylene film was opposed to each other and bonded by a table laminator, ultraviolet rays were irradiated to cure the adhesive. After pasting, hold the edge of the polyetheretherketone film 180 °
By peeling in the direction, the liquid crystal polymer layer was peeled at the interface, and the liquid crystal polymer layer was transferred to a polypropylene film. Then, an acrylic adhesive was applied to the air side of the transferred liquid crystalline polymer layer to a thickness of 20 μm, and then a thickness of 2 μm was applied.
A 35 mm × 45 cm acrylic plate having a size of 35 mm was attached using a desktop laminator. After attaching to the acrylic plate, hold the end of the polypropylene film by hand and rotate it 180 °
The polypropylene film was peeled off in the direction and peeled at the interface between the polypropylene film and the cured acrylic adhesive. The thickness of the element composed of the liquid crystalline polymer layer produced on the acrylic plate in this manner was 9 μm including the cured acrylic resin adhesive layer.

Example 2 A film consisting of the liquid crystalline polymer layer (2) oriented and formed on the polyimide obtained in Production Example 2 was cut into 20 cm × 30 cm, and a spin coater was used on this polymer liquid crystal layer. Then, a commercially available epoxy UV curable resin was applied to a thickness of 2 μm. Next, the peel strength at the interface with the cured epoxy resin (180 ° peel test) is 10 gf / 25 mm on the coated surface.
After a polyethylene terephthalate film having a thickness of 50 μm and a size of 25 × 35 cm is attached using a table laminator, a predetermined amount of ultraviolet rays is irradiated to cure the film.
Pasted Next, the interface between the polyimide film and the liquid crystalline polymer layer was gently peeled off using a roll, and the liquid crystalline polymer layer was transferred to the polyethylene terephthalate film. Next, the air side of the transferred liquid crystalline polymer layer and the pressure sensitive adhesive side of a polarizing plate (size 25 × 35 cm) with a pressure sensitive adhesive were made to face each other, and they were bonded together using a laminator. The bonding angle between the two is 0 between the molecular orientation axis (rubbing axis) of the liquid crystal polymer layer on the air surface side and the transmission axis of the polarizing plate.
Pasted together at °. After sticking to the polarizing plate, stick an adhesive cellophane tape to the corner end of the polyethylene terephthalate film, pull the adhesive cellophane tape in the direction of 180 ° and peel the polyethylene terephthalate film at the interface between the polyethylene terephthalate film and the cured epoxy resin layer. Let In this way, the film thickness of the device composed of the liquid crystalline polymer layer is about 1 including the epoxy resin layer.
A very thin element having a thickness of 0 μm could be formed on the polarizing plate. Next, the liquid crystal polymer layer / polarizing plate element and the polarizing plate are arranged so that the liquid crystal polymer layer is centered, and the angle formed by the transmission axes of the upper and lower polarizing plates is 90 °. After setting, white light was made incident from the lower polarizing plate side. The transmittance obtained by arranging two polarizing plates so that their transmission axes are parallel to each other when white light is incident and using the amount of transmitted light as a reference is almost 100%, and the optical rotator obtained in this example is shown. Is the entire wavelength range (400 to 800 n
It was found that it was rotated by 90 ° in m).

Example 3 A film comprising the liquid crystalline polymer layer of (3) oriented and formed on the polyethylene terephthalate film obtained in Production Example 3 was cut into a size of 20 × 30 cm, and on this liquid crystalline polymer layer, Using a bar coater, a commercially available ultraviolet curable acrylic oligomer adhesive was applied to a thickness of 5 μm. Next, the peel strength at the interface with the cured acrylic resin adhesive layer (180 ° peel test) was 20 gf / 2 on the coated surface.
A 5 mm corona discharge-treated polyethylene terephthalate film having a thickness of 50 μm and a size of 25 × 35 cm was made to face the corona discharge-treated surface side and bonded by a laminator, and then ultraviolet rays were irradiated to cure the adhesive.
After sticking, the end portion of the polyethylene terephthalate film was held by hand and peeled in the direction of 180 ° to be peeled at the interface with the liquid crystalline polymer layer, and the liquid crystalline polymer layer was transferred to a polyethylene terephthalate film subjected to corona discharge treatment. . Next, an acrylic pressure-sensitive adhesive was applied to the air surface side of the transferred liquid crystalline polymer layer to a thickness of 25 μm, and then gently adhered to the glass substrate above the STN liquid crystal cell for testing using a rubber roll. At that time, the bonding angles of the both were set to the arrangement shown in FIG. After attaching the liquid crystal cell to the glass substrate, attach the adhesive scotch tape to the corner edge of the topmost corona discharge treated polyethylene terephthalate film, pull the adhesive scotch tape in the direction of 180 ° and corona discharge at the interface with the cured acrylic resin layer. The treated polyethylene terephthalate film was peeled off. Thus, a thin film optical element having a thickness of about 9 μm including the liquid crystal polymer layer, including the acrylic resin layer, could be formed on the liquid crystal cell. Next, on the liquid crystal polymer layer of the device consisting of this STN liquid crystal cell / liquid crystal polymer layer,
A polarizing plate was attached in the arrangement shown in FIGS. 2 and 3. The display color of this liquid crystal cell is completely black and white, and the contrast ratio is
The brightness was 65 and the brightness was 110 cd / m ² .

Example 4

[0117]

[Chemical 38]

Mixed polymer of formula (4) (logarithmic viscosity 0.1
5, Tg = 118 ° C., logarithmic viscosity of optically active polymer of 0.
A parachlorophenol / tetrachloroethane mixed solvent (weight ratio 70/30) solution having a concentration of 18) of 15 WT% was prepared. Rubbed polyphenylene sulfide film as an alignment substrate (thickness 50 μm, size 30 × 3
0 cm) and the coating solution was applied thereon by spin coating. After drying, heat treatment at 180 ℃ for 30 minutes,
It was cooled and fixed. The twist angle of the liquid crystalline polymer layer is -90.
°, Δn · d was 2.2 μm. Then, a commercially available ultraviolet-curable acrylic oligomer adhesive was applied to the liquid crystal polymer layer on the polyphenylene sulfide film to a thickness of 10 μm by spin coating. Next, on the coated surface, a polyethylene terephthalate film of high release type in which the surface of a polyethylene terephthalate film was coated with silicone as a releasable substrate (strength of 180 ° peeling at the interface with the cured acrylic resin adhesive layer was 8 gf / 25 mm) This silicone-coated surface side was made to face each other by using, and was bonded by a laminator, and then ultraviolet rays were irradiated to cure the adhesive. After sticking, the polyphenylene sulfide film was peeled off at the interface with the liquid crystalline polymer layer, and the liquid crystalline polymer layer was transferred to a high peeling type polyethylene terephthalate film treated with silicone. Next, on the air side of the transferred liquid crystalline polymer layer, a liquid containing the same UV-curable acrylic oligomer used as an adhesive was applied by a spin coating method to a thickness of 10 μm, and then low peeling was performed. The silicone-treated polypropylene film was laminated and cured by irradiating ultraviolet rays from the polypropylene film side. After curing, the silicone-treated polypropylene film was peeled off to form a 10 μm cured acrylic resin layer as a protective layer for the liquid crystalline polymer layer. Next, the thickness is 1 mm,
A cured acrylic resin applied as a protective layer for a liquid crystalline polymer layer, which is obtained by applying an acrylic adhesive to a thickness of 15 μm on a flat blue glass plate having a size of 35 × 35 cm and transferred to a high release type polyethylene terephthalate film. The layer surfaces were made to face each other and laminated using a laminator. After pasting, attach adhesive cellophane tape to the corner edge of the high peeling type polyethylene terephthalate film and pull in 180 ° direction to peel off the high peeling type polyethylene terephthalate film and peel at the interface with the cured acrylic resin protective layer. It was In this way, a thin film device having a film thickness of 28 μm including the liquid crystal polymer layer, including the acrylic resin layer as the protective layer, could be produced on the glass plate. Next, the element composed of this liquid crystalline polymer layer / glass plate was placed at an angle of 0 ° between the transmission axis of the lower polarizing plate and the molecular orientation axis direction of the liquid crystalline polymer layer on the surface in contact with the lower polarizing plate. It was set between two polarizing plates so that the angle formed by the side polarizing plate and the upper polarizing plate was 90 °, and white light was made incident from the lower polarizing plate side. Transmittance obtained by arranging two polarizing plates so that their transmission axes are parallel to each other, setting a glass plate with a thickness of 1 mm between them, and using the amount of transmitted light when white light is incident on the polarizing plate surface as a reference. Was almost 100%. It was found that the thin film optical rotatory element obtained in this example was rotated by 90 ° in the entire wavelength range (400 to 800 nm) in which the direction of the incident linearly polarized light was examined.

Example 5 Using the polymer solution of the formula (3) prepared in Preparation Example 3,
A glass plate having a rubbing-treated polyvinyl alcohol layer as an alignment substrate (thickness 1.1 mm, size 20 × 2)
0 cm) was applied by spin coating and then dried.
Next, heat treatment was performed at 180 ° C. for 30 minutes, and further cooling was performed to fix the orientation. The twist angle of this liquid crystalline polymer layer is −
228 °, Δn · d was 0.84 μm. Next, a commercially available epoxy-based UV-curable resin having a thickness of 1 μm was coated on the liquid crystal polymer layer by spin coating to a thickness of 1 μm.
After bonding a polyether ether ketone film of 00 μm and size of 25 × 25 cm (strength of 180 ° peeling at the interface with the cured epoxy resin layer was 6 gf / 25 mm), it was cured by UV irradiation and then bonded. . Next, this was immersed in water for 1 hour, then the interface between the alignment substrate and the liquid crystalline polymer layer was gently peeled off in water, and the liquid crystalline polymer layer was transferred to a polyether ether ketone film. After the water was dried, the air side of the liquid crystalline polymer layer and the pressure sensitive adhesive side of the polarizing plate (size 20 × 20 cm) with an adhesive were opposed to each other, and they were attached using a laminator. The bonding angle between the two was the same as in FIG. After sticking to the polarizing plate, stick the adhesive vinyl tape to the corner end of the polyetheretherketone film and pull the sticky vinyl tape in the direction of 180 ° to peel off the polyetheretherketone film at the interface with the cured epoxy resin layer. It was In this way, a thin optical element for STN color compensation was formed on the polarizing plate, with the thickness of the liquid crystal polymer layer including the epoxy resin layer being about 9 μm. When the color compensating effect of the STN liquid crystal cell of the thin film element / polarizing plate made of this liquid crystalline polymer layer was evaluated according to Example 3, the display color was completely black and white.

Example 6 A film comprising the liquid crystalline polymer layer of (2) oriented and formed on the polyimide film obtained in Production Example 2 was 20 × 30.
Then, a commercially available ultraviolet-curable acrylic oligomer adhesive was applied to a thickness of 3 μm on the liquid crystal polymer layer by a spin coater method. Next, a commercially available easy-adhesion grade polyethylene having a peel strength (180 ° peel test) at the interface with the cured acrylic resin adhesive layer of 35 gf / 25 mm on the coated surface, the surface of which is coated with an organic thin film Terephthalate film (thickness 50μ
m, size 25 × 30 cm), the coated surfaces were made to face each other and bonded by a laminator, and then the adhesive was cured by irradiating ultraviolet rays and bonded. Next, an adhesive rubber roll was attached to the end of the polyimide film and rolled in the direction of 180 ° to peel off the polyimide film at the interface with the liquid crystalline polymer layer. Next, the side surface of the liquid crystal polymer layer transferred to the polyethylene terephthalate film of easy-adhesion type and the adhesive composed of an ultraviolet-curing acrylic oligomer were applied to a thickness of 5 μm using a bar coater to give a thickness of 100 μm. Face the adhesive coated surface of the polyethersulfone film (size 20 × 30 cm),
After sticking using a laminator, ultraviolet rays were irradiated from the polyether sulfone film side to cure the adhesive and stick. After sticking, an adhesive cellophane tape was stuck to the corner end of the easily adhesive polyethylene terephthalate film, and the adhesive cellophane tape was pulled in the direction of 180 ° to peel off the easily adhesive polyethylene terephthalate film at the interface with the cured acrylic resin layer. . The film thickness of the optical rotatory optical element composed of the liquid crystal polymer layer formed on the polyether sulfone film in this way is
It was a thin film of about 16 μm including the cured acrylic resin layer.

Examples 7 to 11 Rolling out of a long film, a winding device, a gravure roll coater capable of continuously applying an adhesive, a laminator,
A continuous coater laminator device equipped with a continuous UV irradiator and a peeling roll was used. A long film (150 m in length) composed of a liquid crystalline polymer layer oriented and formed on the polyimide film produced in Production Example 2 was fed to a roll 1, and as a releasable substrate, a cured acrylic resin adhesive Peel strength at the interface with the layer (180 °
Peeling test) 10gf / 25mm, thickness 100μ
A long polycarbonate film (length: 500 m) having a width of m and a width of 30 cm was set on the pay-out roll 2. Both substrate films were started to be conveyed at 2 m / min. After the start of transportation, a commercially available UV-curable acrylic oligomer adhesive was continuously applied to the polycarbonate film with a gravure roll coater (80 lines / inch roll) to a thickness of 5 μm, while the applied surface and the oriented substrate film were coated. The liquid crystal polymer layer was made to face the air surface side and continuously laminated, and then a predetermined amount of ultraviolet rays was continuously irradiated from the polycarbonate film side of the laminated film. Further, after irradiation with ultraviolet rays, the polyimide film was conveyed while being held by a rubber roll for peeling in order to peel it from the laminate film, and the polyimide film was peeled at the interface with the cured acrylic resin layer. This series of steps was continuously carried out to transfer the liquid crystal polymer layer onto the polycarbonate film, and the film was wound up on a winding device. Thus, a long film in which the liquid crystal polymer layer was transferred to the polycarbonate film was produced. Next, the obtained film was cut out (20 × 30 cm), and an optical element was manufactured by adhering to various transparent substrates and peeling the polycarbonate film of the releasable substrate. At the time of adhesion to the transparent substrate, the acrylic adhesive has a thickness of 20 μm and is applied to the transparent substrate side, and the commercially available ultraviolet-curable acrylic oligomer adhesive is made thick by spin coating. The thickness of 5 μm was applied to the side of the liquid crystal polymer layer on the polycarbonate film, and the side of the polycarbonate film was irradiated with ultraviolet rays to cure and adhere. After sticking to the translucent substrate, peeling of the polycarbonate film was done by sticking adhesive scotch tape to the corner edge of the polycarbonate film and pulling in 180 ° direction, and peeling at the interface between the polycarbonate film and the cured acrylic resin adhesive layer. Let The results are shown in Table 1.

[0122]

[Table 1]

As described above, it was possible to manufacture and fix a thin film having a thickness of 20 μm or less, including the cured acrylic resin adhesive layer, on the element composed of the liquid crystalline polymer layer on various transparent substrates.

Example 12 (Durability test of thin polymer liquid crystal film) Production of samples for durability test Samples 1 and 2 of the production method of the present invention (continuous device of thin polymer liquid crystal films Examples 7 to 11) The liquid crystal polymer layer produced by the above is cut out from the film transferred to a polycarbonate film, and the air side of the liquid crystal polymer layer and the pressure sensitive adhesive side of the polarizing plate with a pressure sensitive adhesive are opposed to each other and attached using a laminator. The lamination angle was the same as in Example 4. Next, the laminated film attached was cut into a B-5 size, and then the polycarbonate film was peeled off at the interface with the cured acrylic resin layer. After that, the acrylic adhesive is applied to the cured acrylic resin layer of the laminated film of the cured acrylic resin layer / the liquid crystal polymer layer / the polarizing plate with the adhesive to a thickness of 2
2mm thickness, size 20x
A 30 cm blue plate glass was laminated using a laminator. Then, after treating with an autoclave at 60 ° C. and 5 kg / cm ² for 30 minutes, the temperature was lowered and the pressure was released.

Samples 3 and 4 as Comparative Examples (Polymer Liquid Crystal Film with Support Film) In Examples 7 to 11, the polycarbonate film of the releasable substrate was not used, but a triacetyl cellulose film having a thickness of 80 μm was used. Then, the liquid crystalline polymer layer was directly transferred to the translucent substrate and the triacetyl cellulose film of the supporting film substrate. The thickness of the obtained element with a triacetyl cellulose film was about 93 μm. Next, the obtained film was cut out, and the air side of the liquid crystalline polymer layer and the pressure-sensitive adhesive surface of the pressure-sensitive adhesive-attached polarizing plate were opposed to each other, and they were bonded using a laminator. The bonding angle of both was the same as in Example 4. After sticking, an acrylic adhesive is applied to a thickness of 20 μm on the triacetyl cellulose film of the laminated film of triacetyl cellulose film / cured acrylic resin layer / liquid crystalline polymer layer / polarizing plate with adhesive,
It was attached to a washed soda lime glass having a thickness of 2 mm and a size of 20 × 30 cm by using a laminator. The autoclave treatment was in accordance with Samples 1 and 2. Manufactured sample 1
The high temperature and high humidity test was conducted for ~ 4. The conditions are 60 ℃,
It carried out under 90% humidity for 1000 hours. The evaluation was done visually. The results are shown in Table 2.

[0126]

[Table 2]

Thus, the optical element made of the thin polymer liquid crystal film obtained by the production method of the present invention (Samples 1 and 2) is an optical element made of the polymer liquid crystal film with a supporting film (Samples 3 and 4). It showed even higher temperature and humidity test results and was found to have high reliability over a long period of time.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a method for producing a thin film polymer liquid crystal film of the present invention.

FIG. 2 is a cross-sectional view of a liquid crystal cell used in an example of the present invention.

FIG. 3 shows the mutual relationship of the optical axes of the materials forming the liquid crystal cell used in the examples of the present invention.

[Explanation of symbols]

11 Alignment Substrate 12 Compensation Layer (Liquid Crystalline Polymer Layer) 13 Adhesive Layer 14 Translucent Substrate 15 Compensation Plate 21 of the Invention Upper Polarizing Plate 22 Compensation Plate 23 of the Invention STN Liquid Crystal Cell 24 Lower Polarizing Plate 31 Lower Polarizing Plate Transmission axis 32 Upper polarization plate Transmission axis 33 Lower electrode substrate rubbing direction 34 Upper electrode substrate rubbing direction 35 Alignment direction of molecules on the surface of the compensation layer that contacts the upper electrode substrate 36 of the surface of the compensation layer that contacts the upper polarizing plate Orientation of molecule 3a Twist angle 3b of liquid crystal cell molecule Twist angle 3c of compensator layer 3c angle 3d 3d 34 and 35 angle 3e 31 and 32 angle 3f 32 and 36 angle

Continuation of front page (56) Reference JP-A-5-333313 (JP, A) JP-A-7-63916 (JP, A) JP-A-6-301018 (JP, A) JP-A-5-313151 (JP , A) JP-A-6-3525 (JP, A) JP-A-8-62558 (JP, A) JP-A-61-279802 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB) Name) G02F 1/13363 G02F 1/1335 G02F 1/1333 G02F 1/1337 G02F 1/13 101 G02F 1/13 505 B29D 11/00 G02B 5/00

Claims (4)

(57) [Claims] 1. A is cured after a film-like layer of a liquid crystalline polymer which is oriented formed on the alignment substrate was allowed adhesion and removability substrate via a curable adhesive, the cured adhesive
Then, the alignment substrate is peeled off, the liquid crystalline polymer film layer is transferred to the removable substrate, and then cured.
A method for producing a liquid crystalline polymer film, which comprises peeling a removable substrate while leaving a layer . Wherein is cured after a film-like layer of a liquid crystalline polymer which is oriented formed on the alignment substrate was allowed adhesion and removability substrate via a curable adhesive, the cured adhesive
Then, the alignment substrate is peeled off, the liquid crystalline polymer film layer is transferred to the removable substrate, and then cured.
A method of manufacturing an optical element, which comprises peeling a removable substrate while leaving a layer . 3. Is cured after a film-like layer of a liquid crystalline polymer which is oriented formed on the alignment substrate was allowed adhesion and removability substrate via a curable adhesive, the cured adhesive
Then, the alignment substrate is peeled off and the liquid crystalline polymer film-like layer is transferred to the releasable substrate. Then, the liquid crystalline polymer film-like layer is transferred to the opposite side of the releasable substrate side via an adhesive. A method for producing an optical element having a liquid crystalline photo-molecular film-like layer, which comprises peeling the removable substrate after leaving the cured adhesive layer after adhering the optical substrate. 4. The liquid crystal polymer according to claim 2, wherein the liquid crystal polymer is a nematic alignment or a twisted nematic alignment in a liquid crystal state and becomes a glass state at a temperature below a liquid crystal transition point. 3. The method for manufacturing an optical element according to item 3.