JPH09328523A - Heat resistant film - Google Patents

Abstract

(57) Abstract: A heat-resistant film having excellent transparency, heat resistance, and affinity for inorganic and organic compounds is provided. SOLUTION: The component (I) is 40 to 60 mol%, the component (II) is 0 to 20 mol%, and the component (III) is 60 to 4 mol%.
0 mol% and number average molecular weight of 1 × 10 ³ or more and 5 × 1
A heat resistant film made of a maleimide / olefin copolymer having a molecular weight of 0 ⁶ or less. Embedded image Embedded image Embedded image (Here, R ¹ , R ² , and R ³ represent hydrogen or a methyl group)

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent, heat-resistant and inorganic
The present invention relates to a heat resistant film having excellent affinity for organic compounds.

[0002]

2. Description of the Related Art Transparent films are used in various applications such as OHP films and transparent conductive films. O
Polyethylene terephthalate (PET) is mainly used as a base material for the HP film, but a surface-treated film is generally used to improve the adhesion of the toner. Along with the sophistication of presentations, there are demands such as stacking several films and using colors to enhance aesthetics. The PET film is originally inferior in transparency, and the surface treatment further deteriorates the transparency. Therefore, there are problems that the screen becomes dark when stacked and the color definition is poor. Also, PPC
Copying is said to require a temperature of around 150 ° C. for fixing with a toner, and there is a defect that an image is blurred due to curling or waviness due to insufficient heat resistance of the PET film. For transparent conductive films, a film in which ITO is adhered to a PET film is also used, but the transparency is not sufficient and the primer treatment is often required due to insufficient adhesion with ITO, birefringence Has a drawback that it is large and non-uniform so that it becomes unclear in a delicate image, and that the refractive index is large and the light reflectance is high. from these things,
There was a very strong demand for a film having excellent heat resistance, optical properties and affinity with organic / inorganic compounds.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat resistant film which has excellent optical properties, heat resistance and affinity for inorganic and organic compounds.

[0004]

Means for Solving the Problems As a result of intensive studies in view of the above problems, the present inventors have found that a heat-resistant film made of a maleimide / olefin copolymer satisfies the above objects, and completed the present invention. Came to do.

That is, in the present invention, the constituent component (I) shown below is 40 to 60 mol% of the whole polymer, the constituent component (II) is 0 to 20 mol% of the whole polymer, and the constituent component (III) is The present invention relates to a heat-resistant film comprising 60 to 40 mol% of the whole polymer and comprising a maleimide / olefin copolymer having a polystyrene reduced number average molecular weight of 1 × 10 ³ or more and 5 × 10 ⁶ or less. .

[0006]

Embedded image

(Wherein R ¹ represents hydrogen or a methyl group)

[0008]

Embedded image

[0009]

[Chemical 6]

(Here, R ² and R ³ represent hydrogen or a methyl group) The present invention will be described in detail below.

The maleimide / olefin copolymer comprising the above-mentioned constituents (I) to (III) can be obtained, for example, by a radical copolymerization reaction of maleimides and olefins. The compound that provides the constituent component (I) is maleimide or N-methylmaleimide, and N-methylmaleimide is preferable from the viewpoint of mechanical properties and processability. Further, maleimide and N-methylmaleimide may be used in combination.

Examples of the compound providing the constituent component (II) include maleic anhydride. Component (III)
The compounds that give is ethylene, propylene and isobutene, and among these, isobutene is particularly preferable from the viewpoint of heat resistance, mechanical properties and transparency. Further, these compounds can be used in combination of two or more kinds.

The content of the constituent component (I) is 40 to 60 mol% of the whole copolymer, and 45 to 55 mol% is preferable from the viewpoint of mechanical strength and heat resistance. If the constituent component (I) exceeds 60 mol%, the obtained film becomes brittle, and if it is less than 40 mol%, the heat resistance of the obtained film decreases, which is not preferable.

The content of the constituent component (II) is 0 to 20 mol% of the whole copolymer, preferably 0.01 to 10 mol%, more preferably 0.1 to 3 mol%. The inclusion of the constituent component (II) tends to improve the adhesion to the inorganic substance and the organic substance, but the constituent component (II) is 2
If it exceeds 0 mol%, the thermal stability of the resulting polymer tends to be low, and yellowing tends to occur, which is not preferable.

The content of the constituent component (III) is 60 to 40 mol% of the whole copolymer, and 55 to 45 mol% is preferable from the viewpoint of mechanical strength and heat resistance. Constituent (I
When the content of II) exceeds 60 mol%, the heat resistance of the obtained film is lowered, which is not preferable. If it is less than 40 mol%, the resulting film becomes brittle, which is not preferable.

Polymerization of these monomers is carried out by a known polymerization method,
For example, any of bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization can be employed. From the viewpoint of transparency and color tone of the resulting composition, the precipitation polymerization method is particularly preferable.

Examples of the polymerization initiator include benzoyl peroxide, lauryl peroxide, octanoyl peroxide, acetyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide and t-butyl peroxide. Organic peroxides such as oxyacetate and t-butylperoxybenzoate, or 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-butyronitrile), 2,2 ′ -Azobisisobutyronitrile, dimethyl-2,2'-azobisisobutyrate, 1,1'-
An azo initiator such as azobis (cyclohexane-1-carbonitrile) is exemplified.

Examples of the solvent usable in the solution polymerization method include benzene, cyclohexane, dioxane, tetrahydrofuran, acetone, methyl ethyl ketone, dimethylformamide, isopropyl alcohol and butyl alcohol. In particular, as a solvent used for precipitation polymerization, a mixed solvent of an aromatic solvent and an alcohol is preferable.

The polymerization temperature can be appropriately set according to the decomposition temperature of the initiator, but is generally 40 to 150 ° C.
It is preferable to carry out in the range of.

The above maleimide / olefin copolymer can also be obtained by post-imidizing a resin obtained by copolymerization of maleic anhydride and olefins with ammonia, methylamine or the like. In this case, by changing the addition amount of the amine, the component (I)
The ratio of (II) and can be changed.

Such post-imidization reaction is carried out, for example, by dissolving the maleic anhydride / isobutene copolymer in a molten state or by dissolving it in an alcohol solvent such as methanol, ethanol or propanol or an aromatic solvent such as benzene or toluene. It can be produced by dispersing and performing a dehydration ring-closing reaction with a primary amine such as methylamine at a temperature of 100 to 350 ° C.

Here, the number average molecular weight (Mn) of the produced copolymer can be determined by gel permeation chromatography (GPC). The molecular weight of maleimide / olefin copolymer is 1 × 10 ³ or more and 5 × 1
It is preferably 0 ⁶ or less, particularly preferably 1 × 10 ⁴ or more and 1 × 10 ⁶ or less. If the molecular weight exceeds 5 × 10 ⁶ , the formability of the obtained film tends to be poor, and if it is less than 1 × 10 ³ , the obtained film tends to be brittle.

It is also possible to copolymerize other vinyl monomers within a range not exceeding the gist of the present invention. It can also be modified with a compound capable of reacting with the structural unit (II), such as hydroxyethylamine or aminoethanesulfonic acid. Further, other polymers, stabilizers, ultraviolet absorbers, processing aids, flame retardants, antistatic agents, etc. may be added within the scope of the present invention.

The heat-resistant film of the present invention can be formed by known molding methods such as cast molding and extrusion molding. As the solvent used for cast molding, a chlorine-based solvent such as chloroform or 1,2-dichloroethane, dimethylformamide, dimethylsulfoxide, dioxane or the like can be used. The film thickness is 10
The thickness is 500 microns, preferably 50 to 200 microns. When the film thickness is less than 10 microns, the mechanical strength is weak, and when it exceeds 500 microns, the flexibility is reduced. Film feed becomes defective. The obtained film can also be uniaxially stretched or biaxially stretched. Further, the obtained film may be coated with hard coating, antireflection coating or the like. The obtained film has excellent heat resistance, excellent optical properties such as transparency and low birefringence, and has excellent affinity with inorganic and organic compounds. Therefore, it is a film for OHP and a diffusion film for LCD backlight. , Capacitor film, film liquid crystal substrate, ITO-sputtered transparent conductive film, animation cell image film, etc.

[0025]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the examples.

The molecular weight of the produced polymer was determined by gel permeation chromatography (GPC, Tosoh Corp.).
HLC-802A) manufactured by K.K. The composition of the produced polymer is mainly elemental analysis,
^It was determined by ¹ H-NMR measurement. The glass transition temperature of the obtained polymer was measured at a heating rate of 10 ° C./minute using DSC (DSC200 manufactured by Seiko Instruments Inc.). Density was measured according to ASTM D792. The pencil hardness was measured according to JIS K5401. Rockwell hardness was measured according to ASTM D785. The light transmittance is measured by a color difference meter (Model 101D manufactured by Nippon Denshoku Industries Co., Ltd.).
It was measured using P). The birefringence (photoelastic constant) was measured using an opto-rheometer (HRS-100 manufactured by Oak Manufacturing Co., Ltd.). The adhesion test was carried out by printing on a film with a laser printer (Canon laser shot), and a peeling test was performed on the obtained printed matter with cellophane tape. ◎: No peeling, ○: Almost no peeling, △: Partial peeling, ×: All were evaluated in four stages of peeling.

Reference Example 1 Synthesis of Maleimide / Olefin Copolymer 30 equipped with stirrer, nitrogen inlet tube, thermometer and degassing tube
l In an autoclave, N-methylmaleimide 1.2 k
g, t-butyl peroxy neodecanoate 8 g and a mixed solvent of toluene and methanol (1: 1 weight ratio) 15
After charging and purging with nitrogen several times, isobutene was added.
5 l were charged and reacted at 60 ° C. for 6 hours. The obtained particles were dried after centrifugation. The yield was 1.7 kg.

Elemental analysis results of the obtained polymer (C; 6
4.7% by weight, H: 7.8% by weight, N: 8.4% by weight)
Thus, the maleimide units and the isobutene units in the resulting polymer were 50 mol% each. The obtained polymer had a number average molecular weight (Mn) of 95,000.

Reference Example 2 Synthesis of Maleimide / Olefin Copolymer 3 l equipped with stirrer, nitrogen inlet tube, thermometer and degassing tube
In an autoclave, N-methylmaleimide 120g,
11.8 g of maleic anhydride, 0.8 g of t-butyl peroxyneodecanoate and 1.5 l of dioxane were charged, and after purging with nitrogen several times, 0.85 l of isobutene was added.
Was charged and reacted at 60 ° C. for 6 hours.

The obtained solution was poured into hexane to precipitate a polymer. The obtained polymer was filtered and dried. The yield was 150 g. From the results of elemental analysis of the obtained polymer, the maleimide unit, the maleic anhydride unit and the isobutene unit in the produced polymer were 49.5 mol%, 0.5 mol% and 50 mol%, respectively. The obtained polymer had a number average molecular weight (Mn) of 75,000.

Reference Example 3 Synthesis of Maleimide / Olefin Copolymer 3 l equipped with stirrer, nitrogen inlet tube, thermometer and degassing tube
In the autoclave, N-butylmaleimide 0.12k
After g, t-butylperoxyneodecanoate 0.8 and toluene 1.5 l were charged and purged with nitrogen several times, isobutene 0.85 l was charged and reacted at 60 ° C. for 5 hours.

The obtained solution was poured into methanol to precipitate a polymer. The polymer was filtered and dried. The yield was 0.15 kg. From the result of elemental analysis of the obtained polymer, the maleimide unit and the isobutene unit in the produced polymer were each 50 mol%. The obtained polymer had a number average molecular weight (Mn) of 86000.

The copolymers synthesized in Examples 1 and 2 and Comparative Examples 1 and 2 were dissolved in chloroform and cast into 100 μm thick films. Table 1 shows the results of the characteristic evaluation of the obtained film. As Comparative Example 1, the n-butylmaleimide / isobutene copolymer synthesized in Reference Example 3 was similarly cast with chloroform to form a 100-micron film, and the same evaluation was performed. As Comparative Example 2, the same evaluation was performed using a commercially available OHP film made by PET (made by Xerox Co., Ltd.). The results obtained are also shown in Table 1.
Shown in

The heat-resistant temperature (glass transition temperature) of Examples 1 and 2 was close to 160 ° C. and was the most excellent. The density of the sample of the example is relatively low, and the weight can be reduced as compared with the PET film. Further, since the surface hardness is high, the OHP film is also excellent in scratch resistance as compared with the film of the comparative example. The light transmittance is also superior to the PET film. It was also found that the birefringence was small and the film of the present invention had excellent optical characteristics. The film had excellent adhesion to the toner, almost no peeling was observed in the cellophane tape test, and the tendency was further improved by the copolymerization of a small amount of maleic anhydride. On the other hand, in Comparative Example 1, since the heat resistance was not sufficient, heat shrinkage occurred during printing, and a good film could not be obtained. In addition, the adhesion itself was insufficient. The film of Comparative Example 2 was also inadequate in adhesion such as peeling off in the cellophane tape test.

[0035]

[Table 1]

[0036]

As is clear from the examples, the film of the present invention has excellent heat resistance, good transparency and small birefringence, excellent adhesion to inorganic and organic compounds, and OHP.
In addition to sheets, it can be used in many applications such as diffusion film for LCD backlight, capacitor film, electrode for liquid crystal display as transparent conductive film sputtered with ITO, electrode for pen input of touch panel or liquid crystal display, electromagnetic wave shield plate, etc. it can.

Claims (1)

[Claims] 1. The following constituent component (I) is 40 to 60 mol% of the whole polymer, constituent component (II) is 0 to 20 mol% of the whole polymer, and constituent component (III) is 60 to 40 mol of the whole polymer. Mol% and number average molecular weight is 1 × 10 ^3.
A heat-resistant film comprising a maleimide / olefin copolymer having a size of 5 × 10 ⁶ or less. Embedded image (Here, R ¹ represents hydrogen or a methyl group) Embedded image (Here, R ² and R ³ represent hydrogen or a methyl group)