JPH0610266B2 - Polydiacetylene film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to a uniaxially oriented polydiacetylene film. More specifically, the present invention has excellent heat resistance, oxidation resistance and moisture resistance suitable as a polarizing film used for a liquid crystal display element and the like, and has good durability and The present invention relates to a polydiacetylene film which has good film properties and is inexpensive.

[Conventional technology]

In recent years, a polarizing film has been used as an element of a liquid crystal display element in many fields such as a computer, a home electric appliance, an industrial equipment, and a vehicle, and the requirement is to popularize the liquid crystal display element. Along with that, it is growing rapidly.

Conventionally, as the polarizing film, a polymer dichroic polarizing film in which iodine molecules or dye molecules are adsorbed on a polyvinyl alcohol film is mainly used. However, with the expansion of applications of the polarizing film, there is an increasing demand for those having excellent durability, such as heat resistance and moisture resistance, and in the polyvinyl alcohol film,
Since it is not possible to meet such demands, the development of new base materials is desired.

Therefore, it has been attempted to use a hydrophobic resin excellent in heat resistance and moisture resistance as a base material instead of polyvinyl alcohol, and to combine this with a light dichroic dye, but the resin has an affinity with the light dichroic dye. In addition to having insufficient properties, the orientation treatment by stretching treatment is not sufficient, and a polarizing film having practical utility has not been obtained.

Further, recently, a polarizing film composed of a liquid crystalline polymer compound and a photodichroic dye has been proposed (JP-A-60-2).
18602). However, even in this polarizing film, it cannot be said that the affinity between the polymer compound and the dichroic dye is sufficient, and the liquid crystal polymer compound has a problem that it is relatively expensive. ing.

Further, a polyvinylene polarizing film is known as a polymer compound itself having a polarizing property. This product undergoes intramolecular dehydration or intramolecular dehydrochlorination of vinyl-based polymers such as polyvinyl alcohol and polyvinyl chloride,
A polyene structure is formed to impart polarization properties. However, this polarizing film has a drawback that it is inferior in polarizing performance and heat resistance.

Incidentally, polydiacetylene is known to have special electrical characteristics and optical characteristics, and it has been attempted to utilize these characteristics as a base material for various devices. For example, a semiconductive organic thin film (JP-A-60-23906) using this material, a recording element (JP-A-56-147807) utilizing its thermochromic property, and the like have been proposed.

It is also suggested that the polydiacetylene can be used as a base material for polarizing films (US Pat. No. 4,
220,747). However, this polydiacetylene has problems such as being relatively expensive in addition to being inferior in oxidation resistance and film-forming property, and at present, a polarizing film made of polydiacetylene has not yet been put into practical use. is there.

[Problems to be solved by the invention]

Under these circumstances, the object of the present invention is to utilize the optical characteristics of polydiacetylene, and to have excellent heat resistance,
It is an object of the present invention to provide a polydiacetylene-based film which has oxidation resistance and moisture resistance, has good durability, has good film-forming properties, and is inexpensive, and which is suitable for use as a polarizing film.

[Means for solving problems]

As a result of intensive studies by the present inventors, a film was prepared using a resin mixture of polydiacetylene and another resin as a base material, and the film was uniaxially oriented,
It has been found that the above object can be achieved, and the present invention has been completed based on this finding.

That is, the present invention comprises polydiacetylene and a transparent thermoplastic resin, and the content of polydiacetylene is 0.1 to 0.1%.
The present invention provides a polydiacetylene-based film, which comprises a resin mixture of 70% by weight as a base material and is uniaxially oriented.

The diacetylene compound used as the raw material monomer of polydiacetylene in the present invention has a general formula R ₁ -C≡CC≡CR ₂ (I) (in the formula, R ₁ and R ₂ may be the same or different. Well, each, And R ₃ is an alkyl group, m is 0 or an integer of 1 to 15, and n is an integer of 1 to 15. ) The compound shown by these can be mentioned.

The polydiacetylene used in the present invention has the general formula (I)
It can be obtained by heat-polymerizing the diacetylene compound represented by or by irradiating electromagnetic waves such as ultraviolet rays, gamma rays, electron rays, and alpha rays to polymerize. This polymerization reaction is usually performed under atmospheric pressure in an inert gas atmosphere such as argon gas.

Examples of the transparent thermoplastic resin used in the resin mixture as the base material of the film of the present invention include polystyrene, acrylic resin, polycarbonate, polyamide, polyolefin, polyester, modified liquid crystal polyester and the like.

The content of the polydiacetylene in the resin mixture composed of these resins and polydiacetylene is preferably in the range of 0.1 to 70% by weight. This amount is 0.1% by weight
If it is less than the above range, the characteristics of the polydiacetylene of the obtained film cannot be obtained, and if it exceeds 70% by weight, the film-forming property is deteriorated and the oxidation resistance of the obtained film is deteriorated to deteriorate the durability. In particular, when aiming at polarization characteristics, 0.5
-20% by weight, and in this case 0.5
If it is less than 20% by weight, the polarization performance will be poor, and if it exceeds 20% by weight, the transparency will be deteriorated.

The method of mixing the transparent thermoplastic resin and polydiacetylene is not particularly limited, and a method conventionally used for mixing resins can be used. In addition, a resin mixture can be obtained by dissolving polydiacetylene and a monomer of the resin in a desired solvent and bringing them into the polymerization conditions of the monomer.

In the present invention, the resin mixture thus obtained is used to prepare a film, but if desired, a photodichroic organic dye may be added to the resin mixture to prepare a film.

The photodichroic organic dye means a dye having a property that the linear structure has different linear absorptions in one direction and in a direction perpendicular to the one direction in its molecular structure, and is selected from ordinary organic dyes and pigments. However, among these, those that can be dissolved in the resin mixture are desirable, and those that can control the orientation together with the polymer chain are preferable.
The addition amount of this dichroic organic dye is usually 0.001 to 10% by weight, preferably 0.01, based on the resin mixture.
It is appropriately selected within the range of from 3% by weight to the desired degree of coloring of the final film.

The film of the present invention is obtained by forming a resin mixture obtained by mixing pre-mixed polydiacetyle and a resin other than polydiacetylene by a solvent casting method or a melt extrusion method, and then orienting the film in a uniaxial direction. You can Further, a monomer of a resin other than polydiacetylene is mixed with polydiacetylene, and after film formation, or after film formation and alignment treatment (or while alignment treatment is performed), the monomer is polymerized to give a predetermined resin mixture. It is also possible to obtain a base film of It is also possible to blend a diacetylene monomer in a resin other than polydiacetylene and perform the same operation as above to obtain a base film of a predetermined resin mixture.

As a method of uniaxially stretching, a method of uniaxially stretching the film in the film flow direction or in the direction perpendicular thereto by a known method such as an ordinary drawing method or roll rolling method is generally used. In this case, the draw ratio is usually selected in the range of 1.5 to 10 times. When a T-die method of extruding from a T-type die to form a film is used as the melt extrusion method, the film may be uniaxially oriented during film formation. No stretching treatment is necessary.

Further, the film of the present invention is provided on a substrate such as a glass plate by applying a solution of the resin mixture to form a thin film layer, and then rabinking the surface to orient the film in a uniaxial direction. You can also

The film which has been subjected to the orientation treatment in this way is usually subjected to a heat treatment in order to fix the orientation.

The thickness of the film of the present invention is generally 1 to 1000 μm, preferably 10 to 300 μm, and if necessary, other resin film may be laminated as a protective layer on the film. As the resin film for lamination, for example, transparent triacetate film, cellulosic film, polyester film, polycarbonate film and the like can be used. As a laminating method, a melt extrusion laminating method, a dry laminating method using an adhesive, a wet laminating method, or the like is preferably used, and the laminating may be performed on only one side or both sides of the frame of the present invention. .

〔Example〕

Next, the present invention will be described in more detail with reference to Examples.
The invention is in no way limited by these examples.

Example 1 In the general formula R ₁ -C≡CC≡CR ₂ , R ₁ and R ₂ are Soluble diacetylene is filled in an ampoule, ⁶⁰ Coγ
After irradiation with −ray of 50 Mrad for polymerization, the product was purified to obtain polydiacetylene.

This polydiacetylene was dissolved in chloroform to prepare a 1 wt% solution, and 3 ml of this solution was added to chloroform 60 ml.
A solution of 3 g of polymethylmethacrylate in ml was added and sufficiently stirred, and then a transparent purple film having a thickness of about 100 μm was prepared by a casting method. Next, this film is stretched at 90 ° C. to a draw ratio of 5
The oriented film was obtained by uniaxial stretching (double maximum stretchable ratio).

When two relative orientation films thus obtained were overlapped and the relative angle was changed, the color was dark when they were orthogonal to each other, and the color was thin when they were parallel to each other, and polarization was recognized.

Example 2 In Example 1, R ₁ and R ₂ are A transparent pink film was obtained in the same manner as in Example 1 except that the polydiacetylene was used. Then draw ratio 1
The oriented film was obtained by uniaxially stretching 0 times (the maximum stretchable ratio). This film also had a polarization property.

Example 3 An oriented film was prepared in the same manner as in Example 1 except that the amount of the polydiacetylene chloroform solution in Example 1 was changed from 3 ml to 30 ml.

This film was also recognized as having a polarization property.

Comparative Example 1 The polydiacetylene-only film of Example 1 had a maximum draw ratio of 3 times and was not transparent.

Comparative Example 2 The polydiacetylene-only film of Example 2 had a maximum draw ratio of 3 times and was not transparent.

Example 4 In the general formula R ₁ -C≡CC≡CR ₂ , R ₁ and R ₂ are Was used to obtain polydiacetylene in the same manner as in Example 1.

This polydiacetylene was dissolved in chloroform to prepare a 1 wt% solution, and 30 ml of this solution and chloroform 2
After mixing 3 ml of a solution in which 15 g of polymethylmethacrylate was dissolved in 00 ml, this solution was applied to a glass plate and the surface of a coating film having a thickness of 3 μm was rubbed to obtain an alignment film. This film was confirmed to have a polarization property.

〔The invention's effect〕

The uniaxially oriented polydiacetylene-based film of the present invention has excellent heat resistance, oxidation resistance, transparency and moisture resistance, and has good durability and good film formability, And has excellent characteristics such as being inexpensive, in particular, besides being suitably used as a polarizing film which is one element of a liquid crystal display element, it is also useful as a material for display recording materials and optical materials, and further, It can also be used as a semiconductive film or a conductive film by doping with a dopant.

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Claims (2)

[Claims] 1. A resin mixture comprising polydiacetylene and a transparent thermoplastic resin, wherein the resin mixture having a polydiacetylene content of 0.1 to 70% by weight is used as a base material and is oriented uniaxially. Polydiacetylene film. 2. The polydiacetylene film according to claim 1, which is a polarizing film.