JPH06297558A - High strength and heat-resistant film or sheet - Google Patents

Abstract

PURPOSE:To improve beam permeability, resistance to heat and the like and further improve tensile elongation, tensile strength and the like by orienting a polygurtarimide resin film or a sheet composed of the pecified structure unit of specified ratio in the monoaxial or biaxial direction in the range of specified orientation temperature and ratio. CONSTITUTION:A film or a sheet is composed of polygurtarimide containing the structural unit of the formula I of 20wt.%. The film or the sheet composed of the formula ((R1 and R2 are hydrogen atoms and/or 1-4C hydrogen carbon, and R3 is composed of one or two kinds selected from hydrogen, 1-12C hydrogen carbon, cycloalkyl, an aromatic radical such as benzyl, phenyl or naphthyl and a heterocyclic compound.) is placed in the temperature range higher by 2-50 deg.C than the glass transition temperature and oriented in the range of 1.2-5.0 times in size.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyglutarimide film or sheet having high tensile elongation, high strength and excellent heat resistance.

[0002]

2. Description of the Related Art Polyglutarimide resin is known as a resin excellent in transparency, heat resistance and the like, and it is desired to manufacture a film or sheet utilizing the characteristics of this resin. However, as is well known, polyglutarimide resin is extremely inferior in properties based on the flexibility of the resin such as tensile elongation and impact strength, and a film or sheet molded by extrusion molding or the like cannot be handled roughly. It breaks and is not practical.

As a method for improving the flexibility of the above polyglutarimide resin, JP-A-55-80459,
JP-A-58-83055 and JP-A-60-2021
Japanese Patent Publication No. 39 and the like disclose a method of blending a polyglutarimide resin with a rubber component or an impact resistant resin. Although the tensile elongation and the impact strength are improved to some extent by these methods, they are not sufficient, but rather, there is a problem that the transparency, rigidity or heat resistance which is a characteristic of the polyglutarimide resin is deteriorated. It is difficult to manufacture a film or sheet that makes full use of the original characteristics of the resin.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a highly practical film having excellent tensile elongation, tensile strength and the like without deteriorating the properties such as transparency and heat resistance of the polyglutarimide resin. The challenge is to get a seat.

[0005]

The present invention relates to a polyglutarimide film or sheet having improved physical properties by stretching. That is, the present invention provides a film or sheet comprising a polyglutarimide resin containing 20% by weight or more of the structural unit of the formula (I) in a temperature range of 2 to 50 ° C. higher than the glass transition temperature of the resin. ~
The present invention relates to a film or sheet obtained by stretching in a range of 5.0 times.

It is generally well known that the properties of crystalline resins are improved by the stretching method, but it is difficult to improve the properties such as tensile elongation by stretching of the amorphous resins. Polyglutarimide resin is amorphous,
Heretofore, little research has been conducted on the improvement of film properties by the stretching method, and the properties of the stretched film have not been known. However, the stretching conditions of the polyglutarimide resin film or sheet having the structure specified in the present application and its characteristics were examined in detail, and by stretching in a specific temperature range to a specific stretch ratio range, polyglutar was obtained. The present inventors have found that the flexibility such as tensile elongation and the mechanical strength such as tensile strength can be improved without lowering the transparency and heat resistance of the imide resin.

The film or sheet of the present invention is a polyglutarimide resin synthesized by reacting an acrylic resin containing methyl methacrylate as a main raw material with ammonia and / or a primary amine, and is a glutar of the formula (I). The resin having an imide structure of 20 mol% or more, preferably 30 to 95 mol% is formed into a film or sheet by a molding method such as extrusion molding, cast molding or press molding, and the film or sheet is stretched at a specific ratio in a specific temperature range. It is manufactured by The content ratio of the glutarimide structure of the formula (I) can be adjusted by appropriately changing the amounts of ammonia and / or primary amine, reaction temperature, reaction pressure, reaction time and the like. The structure of formula (I) may be arranged in blocks in the molecular chain of the polyglutarimide resin, or may be arranged randomly. The proportion of structural units of formula (I) can be quantified by ¹ H-NMR.

When the structural unit of the formula (I) is less than 20 mol%, not only the glass transition temperature inherent to the resin is low, but also the tensile elongation is hardly improved even when stretched, which is not preferable. In producing the film or sheet of the present invention, a polyglutarimide resin having a number average molecular weight of 10,000 or more, preferably 20,000 or more is used. Number average molecular weight is 10
A polyglutarimide resin having a weight average molecular weight of less than 000 is unfavorable because it has low strength such as tensile strength and is difficult to stretch.

The polyglutarimide resin of the present invention has the formula
It may consist of only the structure of (I) or may contain other structural parts. Formula in polyglutarimide resin
Other than the structure of (I), the structure of formula (II) and / or

[0010]

[Chemical 2]

(Here, R ₄ is a hydrogen atom and / or a hydrocarbon group having 1 to 4 carbon atoms, R ₅ is hydrogen, a hydrocarbon group having 1 to 12 carbon atoms, a cycloalkyl group, benzyl, phenyl,
It is composed of one or more selected from aromatic groups such as naphthyl and heterocyclic compound groups. )

Methacrylic esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate and t-butyl methacrylate, acrylic esters such as methyl acrylate, ethyl acrylate, propyl acrylate and t-butyl acrylate, methacrylic acid, acrylic acid, methacrylamide, acrylamide, It is formed by reacting compounds such as acrylonitrile, methacrylonitrile, maleimide, styrene, alkylstyrene, α-methylstyrene and vinyltoluene.

When the structural unit of the formula (II) is contained in the resin, if the proportion of this structure is increased, the effect of improving the tensile elongation by stretching is hardly seen, which is not preferable.
The structural unit of (II) is 40 mol% or less, preferably 30 mol% or less. Further, a plasticizer, a colorant, an ultraviolet absorber, an antioxidant and a lubricant can be added to the polyglutarimide resin. To improve the weather resistance, it is effective to add a benzotriazole-based or benzophenone-based ultraviolet absorber in an amount of about 0.005 to 3% by weight.

The film or sheet of the present invention comprises the above-mentioned unstretched film or sheet comprising a polyglutarimide resin in a temperature range 2 to 50 ° C. higher than the glass transition temperature of the resin, preferably 5 to 40 ° C. higher. To a uniaxial, biaxial or multiaxial direction of 1.2-
It is obtained by stretching in a range of 5.0 times, preferably 1.5 to 3.0 times. The stretching method is not particularly limited, and is heated to a stretchable temperature by a tenter method, an inflation method, a pressing method, or the like,
It is carried out in the range of the optimum stretching speed under the temperature atmosphere.

If the stretching temperature is less than 2 ° C. higher than the glass transition temperature, the film or sheet is easily broken during stretching, which is not preferable. Further, at a temperature higher than the glass transition temperature by 50 ° C. or higher, it is difficult to stretch uniformly, and tensile elongation, tensile strength and the like are hardly improved, which is not preferable. Further, if the draw ratio is less than 1.2 times, the tensile elongation and tensile strength are hardly improved, and if the draw ratio exceeds 5.0 times, uniform stretching cannot be performed and the film is fibrillated, or during stretching. It is not preferable because the film or sheet frequently breaks. Further, in the case of stretching in the biaxial direction, it is practically preferable that the stretching ratios in the longitudinal and transverse directions are substantially the same.

The stretching speed varies depending on the stretching temperature, the stretching method, etc., but is usually in the range of 1 to 5000% / min, particularly preferably 10 to 1000% / min, relative to the length of the film or sheet before stretching. The range of minutes is preferred. Also,
If the film or sheet is left in a heated state after stretching, the effect of improving the tensile elongation and tensile strength of the film or sheet may decrease, so it is preferable to cool the film or sheet immediately below the glass transition temperature of the film or sheet after stretching.

In the present invention, the stretching can be applied to a film or sheet having a thickness in the range of 1 μm to 10 mm, but it is usually preferably 20 μm to 2 mm.
For a film having a thickness of less than 1 μm, the film is apt to break during stretching, and for a sheet having a thickness of more than 10 mm,
It takes a long time to reach an appropriate temperature for stretching to the inside of the sheet, and productivity is reduced, which is not preferable.

[0018]

EFFECTS OF THE INVENTION By stretching a film or sheet made of a polyglutarimide resin composed of a specific structural unit in a specific temperature range and a specific stretching ratio, excellent light transmittance originally possessed by the polyglutarimide resin, It is possible to obtain a film or sheet having greatly improved tensile elongation, tensile strength, etc. without impairing heat resistance and the like.

The present invention will be described in detail below with reference to Examples and Comparative Examples.

EXAMPLES The proportions of the structural units of formula (I) and formula (II) contained in the polyglutarimide resins shown in Examples and Comparative Examples were measured by ¹ H-NMR. The glass transition temperature was measured by using a differential scanning calorimeter DSC-2C type manufactured by Perkin Elmer Co., Ltd., with a sample amount of 10 mg and a temperature increase rate of 20 ° C./min in a nitrogen atmosphere. The glass transition temperature is shown by the transition start temperature determined by the tangent method based on the DSC curve. For tensile strength and elongation, use test pieces cut out from a film or sheet (sampled parallel to the extrusion direction)
It measured according to D638. For light transmittance, use a test piece cut out from a film or sheet, and use ASTM D1
It measured according to 003. In addition, the draw ratio is 25 mm long straight line or 25 mm square grid-like line is drawn on the test piece at a temperature of 23 ° C., and after drawing, the drawn straight line or the length of one side of the grid (L mm) Was read by a scale at a temperature of 23 ° C. and was calculated by the following formula. Draw ratio (times) = L / 25

Examples 1 to 6 and Comparative Examples 1 to 5 25.0 parts by weight of methacrylic resin (copolymer of 99 mol% methyl methacrylate and 1 mol% methyl acrylate, number average molecular weight is about 50,000), methylamine 17. 5
Parts by weight (40% by weight methanol solution) and toluene 2
By adding 5.0 parts by weight to an autoclave equipped with a stirrer at room temperature, heating to 230 ° C. while stirring under a nitrogen atmosphere, reacting at the same temperature, and changing the reaction time,
Polyglutarimide resins containing the proportion of structural units of formula (I) shown in Table 1 were synthesized. After this resin was purified and dried, it was extruded at a temperature of 230 ° C. using an extruder having a cylinder diameter of 15 mm to form an unstretched film having a thickness of about 50 μm. Biaxial stretching machine (Iwamoto Seisakusho, BIX-703 type)
Using the above, the unstretched film was uniaxially stretched in the extrusion direction under the conditions of the stretching temperature and the stretching ratio shown in Table 1 to obtain films having various stretching ratios. The glass transition temperature, tensile strength, tensile elongation and light transmittance of this stretched film were measured. The results are shown in Table 1.
Shown in.

[0021]

[Table 1]

As is clear from the results shown in Table 1, it is understood that the tensile elongation is greatly improved in each of the examples, while the original excellent light transmittance of the polyglutarimide resin is maintained. Moreover, although the tensile strength is originally excellent, it is also considerably improved.

Example 7 10.0 parts by weight of a methacrylic resin (a copolymer of 95% by weight of methyl methacrylate and 5% by weight of methyl acrylate, a number average molecular weight of about 50,000) and 11.9 parts by weight of cyclohexylamine were added at room temperature. The mixture was put into an autoclave equipped with a stirrer, heated to 230 ° C. with stirring under a nitrogen atmosphere, reacted at the same temperature while stirring, and the reaction time was changed to obtain the formula (I) and the formula shown in Table 2. A polyglutarimide resin having the content ratio of the structure (II) was synthesized. After purifying the resin, the resin having a cylinder diameter of 15 mm was extruded at a temperature of 270 ° C. to a thickness of about 1.5.
An unstretched sheet of mm was formed. The unstretched sheet was biaxially stretched at a stretching temperature and a stretching ratio shown in Table 2 using a biaxial stretching machine (BIX-703, manufactured by Iwamoto Seisakusho). The glass transition temperature, tensile elongation, tensile strength and light transmittance of this biaxially stretched sheet were measured. The results are shown in Table 2. Elongation was measured. The results are shown in Table 2.

[0024]

[Table 2]

As is clear from the results shown in Table 2, it is clear that in Example 7, the tensile elongation is greatly improved. Moreover, although the tensile strength is originally excellent, it is also considerably improved.

Claims (1)

[Claims] 1. A polyglutarimide resin containing 20% by weight or more of the structural unit of the formula (I). (Here, R ₁ and R ₂ are a hydrogen atom and / or a carbon number of 1 to 4
R ₃ is one or more selected from hydrogen, a hydrocarbon group having 1 to 12 carbon atoms, a cycloalkyl group, an aromatic group such as benzyl, phenyl and naphthyl, and a heterocyclic compound group. Become. A film or sheet obtained by stretching the film or sheet consisting of (1) to 1.2 to 5.0 times in the temperature range 2 to 50 ° C. higher than the glass transition temperature of the resin.