JPH01235904A - Polarizing film and its production - Google Patents

Abstract

PURPOSE:To provide the polarizing film having a sufficiently high degree of polarization and has excellent durability at and under a high temp. and high humidity by using a uniaxially oriented film formed by stretching and orienting a film consisting of a substd. acetylene polymer or a resin contg. this polymer. CONSTITUTION:The polymer obtd. by metathesis polymn. using a catalyst such as tungsten hexachloride catalyst or molybdenum petachloride catalyst is imparted with high thermal stability, org. solvent solubility, thermoplasticity, stable ray absorption characteristics, etc., by the presence of highly bulky side chains. The polymer is, therefore, a material which allows fabrication such as film formation and stretching/orienting. The film consisting of such polymer or the resin contg. the polymer is thereupon, stretched and oriented by wet stretching or dry hot stretching. While the resultant polarizing film is usable as it is some applications, said film can also be made into the polarizing film provided with protective films having excellent optical transparency and physical strength on one or both faces. The polarizing film having the excellent durability performance and polarization performance is thereby obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an 8-axis oriented film having excellent polarizing properties and made of a substituted acetylene polymer or a resin containing the polymer.

``Prior Art'' Liquid crystal displays are used in watches, calculators, electronic devices, etc., and the amount of polarizing film that is essential for liquid crystal displays is rapidly increasing. Furthermore, the field of use thereof has expanded to office automation equipment, automobile equipment, television broadcasting, etc., but when used in severe environmental conditions, such as in automobile equipment, even better polarization performance and durability are required. Furthermore, polarizing films for ultraviolet light and near-infrared light are also commercially available.

There are many types of polarizing films, but currently the majority are produced industrially, with dichroic substances adsorbed and oriented on polyvinyl alcohol films. Furthermore, depending on the type of dichroic substance, there are two types: (1) iodine-based polarizing film and (2) dichroic dye-based polarizing film. In addition, polyene-based polarizing films obtained by inducing a dehydration reaction from a polyvinyl alcohol film or by forming a polyene through a dehydrochloric acid reaction from a polyvinyl chloride film have also been proposed. ” [Problem to be solved by the invention] However, although the iodine-based polarizing film has a high degree of polarization,
If left in high temperature and high humidity conditions, the iodine sublimes and loses its polarizing properties.

Polarizing films with dichroic dyes adsorbed and oriented have excellent durability under high temperature and high humidity conditions, and there are also films that mix several types of dichroic dyes and exhibit the same neutral dapple color as iodine.
Although it has a wide variety of color tones, such as the ability to produce color displays used in automobile equipment and televisions, it has drawbacks such as uneven dyeing and a low degree of polarization.

Furthermore, polyene-based polarizing films have the disadvantage that the polyene undergoes a morphological reaction due to heat or light, resulting in changes in polarization performance over time, and has not been put to practical use.

On the other hand, substituted acetylene polymers have a polyene structure and can be used as polarizing elements (Japanese Unexamined Patent Publication No. 57-1999).
No. 31911, JP-A No. 58-34807).

However, the stretching method for this polymer film is unknown, and since this polymer has a large molecular extinction coefficient, the light transmittance of a single film is extremely low.

[Complete Means for Solving the Problems] 'In view of the above circumstances, the present inventors have made extensive studies and have developed a film made of a substituted acetylene polymer or a resin containing the polymer, which is stretched and oriented using an appropriate method. They discovered that a uniaxially oriented film has a sufficiently high degree of polarization and is excellent in durability under high temperature and high humidity conditions, leading to the completion of an uninvented invention.

[More Detailed Description of the Present Invention] The substituted acetylene polymer used in the present invention may be any polymer containing substituted acetylene, and refers to a homopolymer or copolymer of substituted acetylene. The structure of this polymer is partially similar to that of conventional polyene-based polymers in that it has a polyene in its main chain, but the latter is difficult to be a fully conjugated system due to the difference in its synthesis method, and there is no residual catalyst. , have completely different chemical properties due to structural differences such as low heat resistance due to side chain residues.

The polymer was synthesized by methods described in the literature (e.g. macro
7.728 (1974), etc.)
That is, it is carried out by metacenos polymerization using a catalyst such as a tungsten hexachloride catalyst or a molybdenum pentachloride catalyst.

Due to the presence of bulky side chains, the polymer has high thermal stability,
It has completely different chemical properties from conventional polyene polymers such as polyacetylene, such as organic solvent solubility, thermoplasticity, and stable light absorption properties. therefore,
The polymer is a material that can be processed such as film formation and stretching orientation.

The substituted acetylene forming the polymer may be either mono-substituted acetylene or di-substituted acetylene. -Substituted acetylene is represented by the following general formula (I).

H-C: C-R (1) In this formula, R is an alkyl group, an aryl group, a halogenated alkyl group, an alkylsilyl group, etc., and these alkyl and aryl groups are such that some of their hydrogens are , and may be further substituted with an alkyl group, an aryl group, an alkoxyl group, an aryloquine group, a halogen, or the like.

Specific examples of the -substituted acetylene polymer include the following. Propyne, ■-butyne, ■-bendine, 3-methyl-1-butyne, ■-hexyne, 3-methyl-1-pentyne, 4-methyl-1-pentyne, 3.3-
Dimethyl-1-butyne, l-heptyne, 3,3-dimethyl-1-pentyne, cyclohexyl acetylene, l-octyne, 3,3-dimethyl-1-nonine, ■-adamantylacetylene, phenylacetylene, p-methylphenyl Acetylene, β-naphthylacetylene, trimethylsilylacetylene, ethoxydimethylsilylacetylene, n-propoxydimethylsilylacetylene, n-hequinyldimethylfurylacetylene, phenyldimethylsilylacetylene, benzyldimethylsilylacetylene, 3
-trimethylsilyl-1-octyne, 3-trimethylsilyl-1-dendi, anoacetylene, 5-cyano-1
- pentyne, propargyl alcohol, methylpropargyl ether, propiolic acid, methyl propiolate, 0-trifluoromethylpenylacetylene, m-trifluoromethyltophenylacetylene, p-tifluoromethylphenylacetylene, p-fluorophenylacetylene, 3~chloro-1-phlobin, 5-chloro-1-pentyne, p-
Chlorophenylacetylene, 3-bromo-1-propyne, 6-bromo-1-hexyne, 0-trimethylnrylphenylacetylene, 0-n hexylphenylacetylene, 0-methylphenylacetylene, 0-n butylphenylacetylene, O-n octyl Phenylacetylene, Q
-Phenylphenylacetylene, 0.0'-dimethyl-
Polymers such as pt-butylphenylacetylene.

Disubstituted acetylene is represented by the following general formula (II).

R'-C30-R2 (■) In this formula, Rl and RM are an alkyl group, an aryl group, a halogen, a halogenated alkyl, etc., and some of the hydrogens of these alkyl and aryl groups are Furthermore, it may be substituted with an alkyl group, an aryl group, an alkoxynyl group, an aryluogyne group, or a halokene group.

Specific examples of the disubstituted acetylene polymer include the following. 2-butyne, 2-pentyne, 2-hexyne, 4-methyl-2-pentyne, 3-hequinone, cyclooctyne, 2-octyne, 3-octyne, 4-octyne, 2-decyne, 5-decyne, ■ = phenyl 1-propyne, 1-p-methylphenyl-1-propyne, 1-phenyl-1-butyne, 1-phenyl-1-hexyne, ■
-Phenyl-1-nonine, diphenylacetylene, phenylpropionic acid, acetylene dicarboxylic acid, l-chloro-1-octyne, 1-chloro-2-phenylacetylene, 1-p-alphenyl-1-propyne, 1.6-
Polymers such as dipromo-1-hexyne, 1-bromo-2-phenylacetylene, and 1-ferrocenyl-1-propyne.

Further, the copolymer mainly means a random copolymer containing substituted acetylene, but does not exclude copolymers such as block copolymers and kraft copolymers containing substituted acetylene. Examples of random copolymers containing substituted acetylene include the following. Phenylacetylene/
p-Methoki.

Phenylacetylene copolymer, phenylacetylene/p
-Methylphenylacetylene copolymer, phenylacetylene/p-chlorophenylacetylene copolymer, phenylacetylene/1-hexyne copolymer, phenylacetylene/3,3-methyl-1-butyne copolymer, phenylacetylene/3 -Methyl-1-heptine copolymer, phenylacetylene/1-octyne copolymer, phenylacetylene/2-octyne copolymer, phenylacetylene/3-octyne copolymer, phenylacetylene/4-octyne copolymer, Phenylacetylene/1-phenyl-
Copolymers such as 1 to propyne copolymers, phenylacetylene/diphenylacetylene copolymers, phenylacetylene/1-chloro-2-phenylacetylene copolymers, and phenylacetylene/styrene copolymers.

The resin containing the polymer may be any resin containing the polymer, and refers to a resin containing the polymer by blending or other methods. The molecular weight of the polymer is not particularly limited, but from the viewpoint of film-forming properties, a number average molecular weight of 10,000 or more is preferred.

Since this polymer has a large molecular extinction coefficient, the thickness of a polarizing film made of a resin containing this polymer is usually 1.
0 μm or less, preferably 5 μm or less, particularly preferably 1
It is less than μm. The formation and stretching of such thin films is preferably carried out by a co-stretching method on a suitable support film.

Molding of a film made of the polymer or a resin containing the polymer may be performed using a method more suitable than conventional film forming techniques such as calendar processing, casting by a solution method or melting method, extrusion molding with a T-die or an inflation guide, slicing, etc. You can choose to do so. Solvents used in the solution method include toluene, benzene, chloroform,
It can be selected from commonly used organic solvents such as carbon tetrachloride and tetrahydrofuran. The support film used when forming the laminated film by the solution method is preferably made of a material that is not dissolved in the casting solvent and can be co-stretched with the polymer.

Furthermore, it is preferable that the support film has high heat resistance and high moist heat resistance. Specifically, the supporting film materials include polyvinyl alcohol, ethylene-vinyl acetate copolymer, polyethylene terephthalate, nylon 6
．． 6, nylon 6, polyacrylic acid, etc.

Stretching and orientation of a film made of the polymer or a resin containing the polymer can be carried out by selecting an appropriate method from among wet stretching, dry heat stretching, and the like. In addition, considering the possibility of thermal decomposition of the polymer, wet stretching, which allows for low-temperature stretching, is a more preferable method.

Here, wet stretching means adding a substance (plasticizer) that exhibits a plasticizing effect to the film and stretching the film. The plasticizer may be arbitrarily selected from those having good compatibility with the resin constituting the film.

The plasticizer can be added at any time, and is added as necessary before and after the fill molding. If the plasticizer is volatile, it can be added by allowing the film and the plasticizer to coexist.

It is preferable to immerse the obtained film in a plasticizer to bring it into a swollen state.

Examples of suitable plasticizers in the present invention include the following. General-purpose products such as phthalic acid esters such as di(2-ethylhexyl phthalate), dibasic acid esters such as anobic acid (2-ethylhexyl), epoxy plasticizers such as butyl epoxyoleate, and fatty acid esters such as butyl stearate. In addition to plasticizers, toluene, xylene,
Aromatic hydrocarbons such as dodecylbenzene, chain or cyclic hydrocarbons such as hexane, octane, and cyclohexane, and organic carboxylic acid esters such as ethyl acetate. The amount of these plasticizers added affects the stretching orientation of the polymer or the resin containing the polymer, but there is no particular restriction as long as the stretching orientation of the polymer or the resin containing the polymer is achieved. Moreover, wet stretching may be performed under heating if necessary. Dry stretching is not particularly limited as long as the conditions are such that the polymer can be thermoplasticized and molded, but it is preferably carried out at as low a temperature as possible. Preferably above the glass transition point Tg of the polymer, cough Tg + 50
°・Within the following range. There is no particular regulation on the stretching ratio necessary to impart polarizing ability, but it may range from 2 to 1 depending on the properties of the polymer.
You can choose within the range of 0x. The polarizing film of the present invention obtained in this way can be used as is depending on the purpose, but it may be made into a polarizing film with a protective film having excellent optical transparency and physical strength on both sides instead of one side. You can also do it.

Further, the polarizing film of the present invention may contain dyes and other color-forming low molecules or color-forming polymers, if necessary. The dye preferably has high dichroism, and examples of other color-forming low molecules include ferric chloride and cupric chloride.

[Examples] Hereinafter, the present invention will be described in more detail based on Examples. Unless otherwise stated in the examples, parts relate to weight.

The degree of orientation was calculated by calculating the half width (ψ°) from the interference on the Debye-Scherrer ring using the following formula using the X-ray diffraction method.

Light transmittance was measured using a spectrophotometer. The degree of polarization was calculated using the following formula.

However, T indicates the transmittance when two polarizing films are stacked in parallel, and T indicates the transmittance when they are stacked at right angles.

Example 1 10 parts of an 0-trimethylsilylphenylacetylene polymer having a number average molecular fi of 670,000 was dissolved in 90 parts of toluene, cast on a glass plate, and dried to obtain a film having a thickness of about 50 μm. The film was swollen with ethyl acetate at room temperature, axially stretched 10 times, and then dried to obtain a uniaxially oriented film. The degree of orientation of the resulting uniaxially oriented film measured by X-ray diffraction was 45.6% for the peak at 2θ-77°.

Example 2 Two parts of an o-trimethylsilylphenylacetylene polymer having a number average molecular weight of 1670.000 was dissolved in 98 parts of toluene and thinly cast onto an ethylene-vinyl alcohol copolymer film having a thickness of 15 μm to form a film having a thickness of approximately 0.0 μm. 5 μm. −
A laminated film of trimethylsilylphenylacetylene polymer was obtained. The laminated film was placed in a tensator containing toluene for several minutes, and immediately after being taken out, it was stretched 4 times in the axial direction at 80°C in the air. 5 of the obtained polarizing film
The degree of polarization at 46 nm was 92%, and the light transmittance was 39%.

Example 3 Used in Example 2. A polarizing film was obtained in exactly the same manner as in Example 2, except that the substituted acetylene polymer shown in Table 1 was used instead of the -trimethylsilylphenylacetylene polymer. Table 1 shows the degree of polarization and light transmittance of the film.
Shown below.

-15~ Example 4 The same procedure as in Example 2 was carried out except that instead of the o-trimethylsilylphenylacetylene polymer used in Example 2, a substituted acetylene copolymer having the copolymer composition shown in Table 2 was used. A polarizing film was obtained. The degree of polarization and light transmittance of the film are shown in Table 2.
Below is a blank space Example 5 In place of the 0-trimethylsilylphenylacetylene heavy metal used in Example 2, a phenylacetylene/styrene copolymer (copolymer i composition) with a number average molecular fi of 4400 was used.
A polarizing film was obtained in exactly the same manner as in Example 2 except that the molar ratio) 0.610.4) was used.

The degree of polarization and light transmittance of the film at 400 nm were 65% and 44%.

Example 6 2 parts of a phenylacetylene polymer having a number average molecular weight of 1'00,000 was dissolved in 98 parts of toluene, thinly cast on a nylon 6.6 film with a thickness of 15 μm, and dried for 15 μm.
It was stretched 4 times in the axial direction at 0°C in air. The polarization degree and light transmittance at 400 nm of the obtained polarizing film are 7
5% and 43%.

Example 7 A 100 μm thick cellulose triacetate film was attached to the polarizing film obtained in Example 2 using a urethane adhesive, and heat treated in a 100° C. dry oven for 1000 hours. The change in polarization degree due to the heating test was 1.9%. In addition, the polarizing film was heated at 90°C and 100% RH for 10
It was treated for 00 hours. The change in polarization degree due to humidification heat test is 2
．． It was 4%.

The degree of polarization of commercially available polyvinyl alcohol iodine polarizing films is approximately 99%, but considering that the degree of polarization decreases to 20% or less after treatment at 80°C, 90% RH for 200 hours, the polarizing film of the present invention It can be seen that not only is the polarizing ability excellent, but it is also highly durable.

Comparative Example 1 A film obtained in exactly the same manner as in Example 2, except that the film was not left in a desiccator containing toluene for several minutes, was made of 〇-trimethylsilylacetylene polymer and was not oriented. It showed no polarizing ability at all.

Comparative Example 2 A film obtained in exactly the same manner as in Example 6, except that instead of stretching in air at 150°C in Example 6, it was stretched in air at 80°C, the phenylacetylene polymer was oriented. It showed no polarizing ability at all.

[Effects of the Invention] According to the present invention, a uniaxial alignment of a substituted acetylene polymer is obtained, and the alignment has a high degree of polarization, and the degree of polarization does not significantly decrease even under high temperature and high humidity of about 100'C4. few. Also, films obtained without dyeing have uneven dyeing. Therefore, the film is a material with excellent durability and polarization performance that can be used under severe environmental conditions such as in automobile equipment.

Patent applicant RiRashi Co., Ltd.

Claims (1)

[Claims] 1. A uniaxially oriented body made of a substituted acetylene polymer or a resin containing the polymer. 2. A polarizing film consisting of a uniaxially oriented film having a thickness of 10 μm or less and made of a substituted acetylene polymer or a resin containing the polymer. 3. A polarizing film, characterized in that the uniaxially oriented film according to claim 2 is laminated with a support film. 4. A method for producing a polarizing film, which comprises co-stretching a film made of a substituted acetylene polymer or a resin containing the polymer and a support film. 5. The method for producing a polarizing film according to claim 4, which comprises wet stretching. 6. The method for producing a polarizing film according to claim 4, which comprises dry heat stretching.