JPS5945124A - Aromatic polyamide film - Google Patents

Abstract

PURPOSE:To obtain a good planar shape after compounding when an aromatic polyamide film is used while being compounded with other metal materials, etc. with the former as a base, by employing such aromatic polyamide which contains coupling units with the basic structure represented by a particular formula not less than 50mol%. CONSTITUTION:The used film contains coupling units each represented by the formula (where m, n are integers of 0-4 and m+nnot equal to 0) not less than 50mol%, has density of 1,400-1,490g/cc substantially only with polymers, and exhibits the product of a coefficient of thermal contraction and a coefficient of thermal expansion at least in one direction on the film plane in a range of 1.0X10<-7>- 1.0X10<-4>[(mm./mm./ deg.C)X(%)]. The above basic structure can be formed by a low- temperature solution polymerizing method, interfacial polymeizing method, molten polymerizing method, solid phase polymerizing method, etc. using combination of, e.g., halide acid and diamine, diisocyanate and dicarbonic acid, etc. Polymerization is performed, for example, such that chloride acid and diamine are reacted by a low-temperature solution polymerizing method in an amide or uranine organic solvent. N-methyl pyrrolidine, dimethylacetoamide, etc. may be used as the organic solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aromatic polyamide film with excellent balance in dimensional change due to heat.

Conventionally, aromatic polyamide films have been considered for use at high temperatures by taking advantage of their heat resistance, or for use in combination with other materials at high temperatures.

However, when aromatic polyamide is used as a single-layer film, it is advantageous to minimize thermal dimensional changes by 1-1 to stabilize flatness and shape, but other materials such as When used in combination with materials that have different thermal dimensional changes, such as metals or different types of polymers, the soot may wrinkle or curl after being used at high temperatures or after making composite materials at high temperatures. It had the disadvantage of having a poor planar shape. Thermal dimensional changes include thermal contraction and thermal expansion, but until now, only one of these characteristics was known to obtain a single-layer film.

The present inventors took into account the balance between these two properties and conducted a thorough study to obtain a basic film for composite materials.

An object of the present invention is to provide a base film for producing a composite material with a good planar shape after composite when an aromatic polyamide film is used as a base in composite with other materials, especially metal materials. /m/'0)X(%)].

The aromatic polyamide in the present invention has a basic structure C1m
Q C], nO m, n is an integer of O to 4, and contains 50 or more moles of bonding units represented by m+n80. If this unit is less than 50 molar units, only a weak film will be obtained when formed into a film, and the coefficient of thermal expansion and coefficient of thermal contraction will tend to be large values, resulting in a film with low practical value. This basic structure is a P-bonded diamide, and it is necessary that at least one benzene ring in one bonding unit has a chlorine substituent. By having a single chlorine substituent, the solubility of the polymer in an organic solvent system is improved and the moisture absorption rate and coefficient of hygroscopic expansion when formed into a film are significantly reduced compared to unsubstituted polymers.

The entire basic structure is manufactured from diamines, dicarboxylic acids, or derivatives thereof corresponding to each of the 8 units by a conventionally known method. For example, low-temperature solution polymerization, interfacial polymerization, melt polymerization, solid phase polymerization, and the like are used depending on combinations of acid oxides and diamines, diisocyanides and dicarboxylic acids, and the like.

More specifically, terephthalic acid, IJ, and 2.

Luterephthalic acid chloride, 2,6 dichloroterephthalic acid chloride and 2chlor p-phenylenediamine.

Combinations with p-phenylene diamine, 2.5 dichlor p-phenylene diamine, 2-methyl 5-chlor p-phenylene diamine, etc., 2-chlor p-phenylene diisocyanate,
p-phenylenediisonanate.

Examples include combinations of 2,5-dichloro p-phenylene diisocyanate and terephthalic acid, 2-chloroterephthalic acid, and 2,6-dichloroterephthalic acid.

The preferred method for polymerization is to react acid chloride and diamine in an amide-based or urea-based organic solvent using a low-temperature solution polymerization method. It can be dissolved again in an organic solvent and used as a film-forming dope.

Hydrogen chloride generated during polymerization can be neutralized with an alkali or alkaline earth base, an epoxy compound, or an organic amine, and then used as a solution dope for film formation. Examples of the organic solvent include N-methylpyrrolidone, dimethylacetamide, dimethylformamide, dimethylimidazolidinone, and N-etherpyrrolidone.

The structural units of the polymer of the present invention are not particularly limited as long as they are less than 50 molar proportions of repeating units, but units forming amide bonds are preferred. Examples of forming these amide bonds include (where X is H or halogen, C, <,

m0 as shown in (indicating alkyl, phenyl)
Examples include sulfone bond-containing units such as 0 N- and C3 to C2o coordinating bond units. Furthermore, as units other than amide, it is acceptable even if the bond contains all bonding units such as -NHCNH- urea bond.

As this copolymer unit, the following structure is more preferable in order to fully exhibit the characteristics of the film.

OO 00 In order to obtain advantages in productivity, stretchability, thick film production, etc. during film formation, it may be preferable to introduce a copolymer unit even if the mechanical properties of the film are slightly sacrificed. The composition of the copolymer may be a random type or a regular copolymer such as a block type. However, it is also possible to use a mixture of two or more types of polymers.

The dope used for film formation is an amide solvent 1 such as N-methylpyrrolidone or dimethylacetamide.

Dimethylformamide, dimethylimidazolidinone, N
It is appropriate to use ethylpyrrolidone etc. as a solvent, and those containing the polymer at a concentration of 1 to 50% by weight are preferably used. It is preferable to improve the solubility and stability of film formation. Preferred halides exhibiting these effects include lithium chloride, lithium bromide, calcium chloride, and calcium bromide.

In order to completely complete the neutralization, ammonia, ethanolamine, amines such as pyridine, various stabilizers, etc. can be completely contained.

The appropriate viscosity of the film-forming dope is 100 to 20,000 voise in the temperature range when casting using a metal such as two nozzles, and the logarithmic viscosity of the polymer η (sulfuric acid 100 m/hnh.

The value measured at 30°C by dissolving 0.5g of polymer in
．． It is desirable that it be in the range of 5 to 6.5.

In the production of the film of the present invention, since the dope generally contains inorganic salts, it is necessary to perform the first wet extraction process. A preferred method is to cast onto a support such as a film or foil and shape it into a smooth surface, and then, depending on the case, partially dry the solvent and transfer to a wet process. In order to dry on the support, the desolvation rate should be at least 0.1 g to prevent foaming due to rapid evaporation of the solvent and to prevent the formation of a skin layer on the surface layer of the cast film and a highly uneven surface. It is preferable to set it to less than /min.cm2. Further, the dope may be discharged in a single layer or in multiple layers during casting.

The cast dope is subjected to a wet process either together with the support or after being dried and peeled off from the support.

It is convenient to use a water-based medium for the wet method, which is a mixture of water and a solvent contained in alcohol or dope.

Extraction from the film in an aqueous solution containing an inorganic salt, water alone, or a bath containing at least 60% water, or spraying of an aqueous solution can be carried out.

In the first stage of the wet process, disadvantageous problems such as uniform extraction from the film and uniform coagulation of the polymer and polymer, such as deterioration of the optical surface shape of the isoilm, deterioration of physical properties, and devitrification phenomenon, occur. It is preferable to carry out a wet process using an aqueous medium at a temperature in the range of 15 to 95 degrees. Self-supporting films containing solvents and aqueous extractants exhibit plasticizing effects;
Stretching can be performed at a relatively low temperature of 200'O or less. Films in a wet bath or outside the bath or immediately after peeling can be stretched using rolls, etc., and the stretching ratio, stretching speed, and temperature can be adjusted to adjust the physical properties of the final film. It is preferable to carry out the adjustment in a range of 0.8 to 3.0 times. The stress during stretching is less than the breaking stress of the film, and is usually suitably less than 18 kg/mm''.

After the first wet process, the film is heated at 200 to 500'C to remove the volatiles contained and improve the film properties.
Drying is carried out at a temperature of This drying is carried out by contact with heated rolls or drying by tenter method, in air or in an inert atmosphere (in nitrogen, straight stretching, heat setting and relaxing, but the stretching ratio, relaxation rate and heat setting conditions are It is an important factor in determining the properties of the film.

The film of the present invention has thermal dimensional change characteristics such that the product of thermal contraction rate and thermal expansion coefficient is 1. Ox 10 ~1. Ox
It needs to be within the range of 10mm/mm/'Ox%. Here, the thermal shrinkage rate is the shrinkage rate under no load at 250°C and is expressed in units of x with respect to the original dimensions, and the thermal expansion coefficient is the shrinkage rate of the film in the temperature range of 80 to 150°0. Thermal expansion of 〇- is expressed in units of total plate/plate/゛0 Films whose dimensional change characteristics are outside the scope of the present invention may have poor dimensional stability at high temperatures or may be composited with various materials. In some cases, problems such as deterioration of flatness such as curling or wrinkles and deterioration of the functionality of these materials occur.

Thermal dimensional changes can vary depending on the composition of the polymer and the conditions during film formation. Among the polymer components, the larger the number of basic structural units represented by the general formula above, the smaller the dimensional change, and the larger the copolymer composition, the larger the dimensional change, but if the composition of the present invention is used, the dimensional change can be adjusted within the range of the present invention. It is possible.

In particular, it is desirable from the above point that the basic structural unit is in the range of 60 to 90 mol.

The two properties of thermal expansion coefficient and thermal contraction coefficient are not independent but can change while having a correlation with each other.In practical terms, it is sufficient that a certain relational expression has a value within a certain range. . Looking at the relationship with film forming conditions, the higher the stretching ratio and the lower the heat setting temperature, the higher the heat shrinkage rate, but the smaller the essential coefficient of thermal expansion. Stretching and heat setting during film forming conditions, which make important contributions to dimensional changes, have a stretching ratio of [1,85 to 4] compared to the area ratio immediately after casting.
Although the stress during stretching is in the range of 8 times, it is preferable to carry out the stretching under a tension of at least 0.1 kg/mm'' at that temperature.The dimensional change of the slender film depends on the degree of tension and relaxation of the polymer chains and the crystallization. Drying and heat setting after the first wet process, which is controlled by the degree of oxidation, but is particularly relevant to relaxation and crystallization, should be between 200 and 50
Mouth°0. Preferably, it is carried out within the range of 260 to 450°0.

The density of the present invention is 1,4 with substantially no additives.
It must be within the range of 00 to 1.490 g/cc. The degree of crystallinity and density within a film is represented by the density, but if this density value is outside the range of the present invention, a brittle film or a film with too large a thermal dimensional change will be produced, making it impractical for practical use. This resulted in a film with many problems.

The importance of thermal dimensional change in the present invention will be explained in more detail. Thermal expansion coefficient 1. Ox 10-mm/mm
/°0 film and 22 × 10 nIII]/m
When a thin adhesive layer of copper foil of m/'O is laminated on the entire culm at 200°A and 8°C and then cooled to room temperature, it curls with the copper inside due to the bimetallic effect. If it has a heat shrinkage rate, it is possible to shrink the film by reheating it to a higher temperature than the lamination temperature and produce a laminate with good flatness at near room temperature. When used in such applications, if one or both of the coefficient of thermal contraction and coefficient of thermal expansion becomes too large, it is not preferable because it falls outside the control range for achieving good flatness.

Although the present invention has all the characteristics of composition, density, and dimensional change characteristics as described above, an even more excellent film can be obtained by reducing the surface roughness of this film. Average roughness of center line (indicated by Ra) is 00
1 μ or less and maximum roughness (denoted by Rt) is 0.1
It is preferable that the value is less than μ, but in order to form such a smooth surface, it is of course necessary to pay attention to filtration of raw materials, dust prevention, and fine dispersion of additives, but also to 16- Surface roughening due to excessive heat treatment must be prevented. In particular, the drying and heat setting conditions for the film are 250 to 420.
Within 10 minutes in the range of °0
) A method in which the film is formed within a value range of 300 to 3.500 is preferable.

Furthermore, the film of the present invention can be given even more excellent properties by having a Young's modulus of 600 to 4000 kg/ml'' in at least one direction and a hygroscopic expansion coefficient of 5 x 10 mm/no/RH (relative humidity) or less. I can do it.

Further, the film of the present invention can be subjected to physical treatment or chemical treatment on the surface of the film in order to improve adhesion and adhesion to other materials, if necessary. As chemical treatments, corona treatment in various atmospheres, low-temperature plasma treatment, flame treatment, etc. are useful.

The gases used for these treatments include oxygen and nitrogen.

Argon, hydrogen, neon, ammonia, water vapor.

Helium, carbon dioxide, nitrogen dioxide, -carbon oxide.

- Various gases such as nitrogen oxide, ozone, sulfur dioxide, and hydrogen sulfide are effective, and a mixture of these gases is often particularly effective. Furthermore, the film of the present invention has isotropic properties, has excellent transparency when the mixing ratio of other materials is small, and has a dense structure, so it has excellent electrical insulation properties and is highly durable. It has excellent chemical properties and is extremely stable except for strong acids such as sulfuric acid and amide solvents.

The film of the invention has a specific polymer structure.

It is a relational expression that has density within a certain range and expansion and contraction due to heat.By having values within a certain range, the flat surface may curl or wrinkle as a composite material, especially when used in combination with other materials. This has the effect of completely preventing deterioration of the shape.

Application examples of the present invention include flexible printed circuits and capacitors used in combination with other materials.

Can be used for diaphragms, bases for magnetic recording media, etc., but only 9%
It is useful when combined with metal materials by vapor deposition, sputtering, or plating, and is ideal as a base for thin-film magnetic recording media.

Next, the measurement method of the present invention will be explained.

The heat shrinkage rate of a film is expressed as a percentage of the shrinkage of an original film with a width of 10 pans and a length of 200 mm after leaving it in an oven at 250°0 for 10 minutes compared to the original size. The humidity condition was that the sample was left in an atmosphere with a relative humidity of 0% (in a P2O, Tenkater, etc.) for 48 hours or more to dehumidify it.

The coefficient of thermal expansion is the dimensional change in the region of 8D to 15D'0 when the film is heated to 15D'0 and then gradually cooled to eliminate all effects of thermal contraction and moisture absorption and desorption. It is calculated from a thermomechanical analyzer (T
MA), etc.

The density of the film was measured at 25° using a lithium bromide-water density gradient tube.

The Young's modulus of the film can be measured using a Tensilon type tensile r tester, and the surface roughness of the film can be measured by a stylus type p-plane roughness meter or by microscopic measurement using interferometry.

The moisture absorption dimensional change of the film was measured by dimensional change iTMA of the film in an adjustable cassix.

All embodiments of the present invention will be explained below.

Examples 1-5. Comparative H u1-6 08 molar ratio of 2chlor p phenylenecyaminte 0.2 molar ratio of 4°4'diaminodiphenyl ether fO79 molar ratio of terephthalic acid chloride and 01 molar ratio of inphthal 96 in dehydrated N-methylpyrrolidone After stirring at 70°C for 2 hours, neutralization was completed by adding 7 molar equivalent of ammonia water, and finally the polymer concentration was 1.
00%, ηinh””Solution viscosity 4500 poise (30°
A film-forming dope of C) was obtained. After filtering this stock solution through wool felt, a sintered metal filter is used to remove more than 90 foreign particles of 10μ or larger! I passed away. The dope was continuously cast through a die onto a drum with a stainless steel surface of 2 m in diameter and 40 ann in width at a rate of 1.2 m/min, and the atmosphere was heated to a total temperature of 170°0 to scatter a portion of the solvent.

After concentrating to a polymer concentration of 40%, the film was peeled off from the drum. This film was continuously introduced into a water bath filled with running water at room temperature to extract residual solvent and inorganic salts, and then placed in a clip-type tenter for drying and heat fixing. At this time, films were collected by various stretching operations in the MD and TD using a nip roll and a tenter placed in a water tank, and with various drying and heat setting temperatures. The basic structural unit of this film is 72φ. After coating the film with a 2μ thick epoxy-nylon vapor deposition agent and drying it, a 30μ thick electrolytic copper foil was applied to the 26”
All properties of the composite laminate pressed at C are shown in Table 1. It has been found that the films within the scope of the present invention have excellent performance both as a single unit and as a laminate.

Example 6. Z, Comparative Example 4.5 0.6 molar ratio of 2chlor p-phenylenediamine and 0.4 molar ratio of 4.41 diaminodiphenylsulfone 4 i,o molar ratio of terephthalic acid chloride in dehydrated dimethylacetamide The reaction was carried out with stirring, and neutralization was carried out in the same manner as in Example 1, resulting in a polymer concentration of 11.5%.

ηinh 2.31 Solution viscosity i31 Doboi, <(3
A film-forming dope of 0'O) was obtained.

Using the same casting, wet and dry heat setting equipment as in Example 1, films were collected under various conditions. The basic course unit for this film is 60 units.

Aluminum was deposited on this film by sputtering to form a layer of 0.2 μm on the entire film.
The temperature of the can during deposition was set at 200'O to improve the adhesion between the film and the aluminum layer. The performance of the obtained film alone and as a laminate is shown in Table 2, and it was found that the film of the present invention exhibited excellent performance.

Claims (1)

[Claims] (Here, m and n are integers from O to 4, and m+n to O
) Contains at least 150 moles of bonding units represented by ) and has a density of 1,400 to 1,490 g consisting essentially of polymer
/cc, the product of the thermal contraction rate and thermal expansion coefficient in at least one direction within the film plane is 1.0x10 to 10x10
An aromatic polyamide film within the range of [: (mm/mm/a) x (%)].