JPS59219335A - Production of heat-resistant laminated film or sheet - Google Patents

Abstract

PURPOSE:To produce a laminated film or sheet of excellent heat resistance, by coating at least one surface of a polyester film or sheet with a polymer containing an imide group in the molecule. CONSTITUTION:At least one surface of a polyester film or sheet is coated with an aqueous solution, emulsion or dispersion containing 0.1-25wt% polymer containing an imide group in the molecule, e.g., aromatic polyimide, and the film is dried. EFFECT:The imido group-containing polymer has high heat resistance, and does not become sticky even at temperature of as high as 100 deg.C, so that the polymer can form a laminated film or sheet which undergoes no blocking and is stable at the time of application of a magnetic layer. USE:Video tape, audio tape, and floppy disk.

Description

[Detailed description of the invention] Concerning the manufacturing method.

[Prior art]

The production of magnetic tapes and magnetic sheets by applying magnetic paint to polyester films or sheets has been carried out on an industrial scale. The impact on performance is extremely large. For example, important surface properties of a base film used in a magnetic tape include easy adhesion to magnetic paint, sliding properties on a non-magnetic surface, and heat resistance during processing. Therefore, in order to impart these characteristics to the surface of the base fill 45, a primer is applied. As this primer, polymeric substances such as polyester, polyurethane, acrylic resin, vinyl resin, etc. are known.

However, primers made of these polymeric substances have the following drawbacks.

(1) Rocking occurs during transportation and storage of the coated base film or sheet.

(2) One layer of the primer is destroyed during the calendering and aging processing during the magnetic mPrmPrm short process.

(In the step of attaching alloy etc. by 31 vapor deposition, the quality of the primer layer is altered or destroyed.

(4) When applying the brimer during the base film forming process, the brimer is transferred to the heating rolls.

(5) It is difficult to treat exhaust gas with organic solvent type brimers.

[Purpose of the invention]

An object of the present invention is to eliminate these drawbacks and provide a method for producing a laminated film or sheet with excellent heat resistance.

[Structure and effect of the invention]

The object of the invention is achieved by the following method.

A method for producing a heat-resistant laminated film or sheet, characterized by:

The method of the present invention has the following features.

That is, the +1+ imide group-containing polymer has high heat resistance and 100
Since it does not exhibit adhesive action even at high temperatures of .degree. C. or higher, the obtained laminated film or sheet does not cause blocking and the gradient during formation of the magnetic layer is stable.

+21! Even when the R-layer film is produced in-line, the polymer layer will not be transferred to a heated metal roll or the like.

(3) Since it is applied as an aqueous footender liquid, there is no need to treat exhaust gas even if it is applied in-line during the formation of the base film.

It has the following features.

In the present invention, polyester refers to terephthalic acid, inphthalic acid, 2,6-naphthalene dicarboxylic acid, 4.4'
- Dibasic acids such as diphenyldicarboxylic acid or ester-forming derivatives thereof, and ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-
Butanediol, neopen + le glycol.

1.5-bentanediol, 1.6-hexanediol, 1.4-cyclohexane dimetatool.

diols such as p-xylylene glycol, hydrogenated bisphenol A, etc. or their ester-forming derivatives,
If necessary, add hydroxycarboxylic acid, monocarboxylic acid,
It is a high melting point, highly crystalline linear polyester synthesized using monoalcohol etc. Examples of such polyliptylene tere7talate, polyethylene-2,6-su7talate, poly(],]4-cyclohexyldimethyl terephthalate, etc. may also be used. Copolymers of these or small proportions of other resins may also be used. Blends with can also be used.

The film or sheet used in the present invention is manufactured by a conventional method using the above-mentioned polyester. For example, it is manufactured by melt-casting polyester into a film.

The films or sheets used in the present invention include unlowly stretched films (sheets), films (sheets) stretched only in a uniaxial direction [uniaxially stretched films (sheets)], and films stretched in two axial directions (vertical and horizontal directions). Film (sheet)
[Biaxially stretched film (sheet)] etc. may be used,
Further, the film (sheet) may be used before or after oriented crystallization is completed, or after oriented crystallization and heat treatment are completed.

1 polymer, which can have the formula 1 in fractional form. Specific examples of this "polymer containing an imide group in the molecule" include aromatic polyimide and aromatic polyamide-imide.

Examples include aromatic polyesterimide and alicyclic polyamideimide. The raw materials for producing this "polymer containing imide groups in the molecule" include trimellitic acid and trimellitic anhydride.

Pyromellitic acid, pyromellitic anhydride, trimesic acid,
Cyclobutanetetracarboxylic acid.

Cyclobutane tetracarboxylic dianhydride, prephthalic acid, terephthalic acid dimethyl ester.

Inphthalic acid, isophthalic acid dimethyl ester, 2,6
-Naphthalene dicarboxylic acid dimethyl 2.6-naphthalene dicarboxylic acid ester.

1.4-cyclohexanedicarboxylic acid, 1.4-cyclohexanedicarboxylic acid dimethyl ester, adipic acid,
7 Polyfunctional carboxylic acids such as divic acid dimethyl ester, phthalic acid, phthalic anhydride, phthalic acid dimethyl ester, etc., or derivatives thereof, p, p'-diaminodiphenylmethane, p, p'-diaminodiphenylsulfone, p , p'-diaminodiphenyl ether, p-phenylenediamine, m-phenylenediamine, 0-phenylenediamine, 1,6-hexamethylenediamine, ethylenediamine, and, if necessary, polyfunctional amines such as glycol. A functional human 1-oxy compound, a carboxylic acid having a hydroxy group or an amine group, an amine having a hydroxy group, etc. can be used. The imide group and its precursor group in the polymer are formed, for example, by reacting a polyfunctional carboxylic acid with a polyfunctional amine or a mixture of the polyfunctional amine and a polyfunctional hydroxy compound. "Polymer containing intramolecular lc7 mido group"
can be manufactured by a conventionally known method. At that time, an organic solvent and/or water can be used as the reaction medium. When an organic solvent is used, the organic solvent is replaced with water after the reaction is completed and before coating.

The final product is an aqueous solution, emulsion, or dispersion.
In the above reaction, it is possible to introduce into the polymer molecule a group that has an affinity for trapped water (for example, a carboxyl group, an amine 7 group, etc.) or adjust the number thereof, and furthermore, it is possible to convert the above group into a hydrophilic salt using an alkali or ammonia. It can also be done. Aqueous solution.

The emulsion or aqueous dispersion is mainly composed of water, but may contain a small amount of an organic solvent. In addition, when preparing these liquids, dispersants, emulsifiers, stabilizers, surfactants,
A lubricant, an ultraviolet absorber, a coloring agent, a filler, a pigment, etc. can be added. The polymer concentration in the aqueous solution, emulsion, or aqueous dispersion is arbitrary, but preferably 0.1 to 25% by weight.

The aqueous solution, emulsion, or aqueous dispersion of the "polymer containing an imide group in the molecule" can be applied using known coating methods such as reverse coating, Kismayer coating, gravure coating, slot die coating, curtain coating, etc. Can be used. The coating thickness is such that the surface layer of the polyester film or sheet is completely covered by the coating film or more.

The heat-resistant laminated film or sheet obtained by the method of the present invention is useful as a base film or sheet for magnetic tapes such as video tapes and audio tapes, and magnetic disks such as floppy disks.

〔Example〕

In order to more accurately explain the embodiments of the present invention, detailed explanations will be given below with reference to examples, but the examples presented here are only a few examples and are not intended to be limiting. .

Note that the measurement items in the examples were measured by the following methods.

L PV value; film standard length 2 under the conditions of diameter 2 μ and load 0.1 g4
For 611111, magnify the reference length direction by 50 times and the surface roughness direction by 20,000 times, remove the chart, and find the reference length from the cross-sectional curve (from the higher one of the straight lines parallel to the average linear pressure of the cut out part) Select the one that passes through the bottom of the valley, and these two
The value obtained by dividing the distance between straight lines by the vertical magnification is expressed in microns, and the average value of 10 Pv values is expressed.

Determine the film roughness curve using the same device as Z CLA value l, extract a part of measurement length L (reference length 2,) in the direction of its center line,
The value given by the slightly quadratic equation where the center line of the cut-out portion is the X axis and the vertical magnification direction is the Y axis is expressed as Y=f(x), and the value is expressed in μ units.

In this measurement, the reference length was set to (1,2511 m+), and the measurement was performed using an 8-scale system, and 3 pieces were excluded from the direction with the largest value, and the average value of the 5 pieces was expressed.

λ Coefficient of dynamic friction (running properties) Figure 1 shows the coefficient of kinetic friction μ used to evaluate film running properties.
(Device 9 used: Japan Automatic Control, KNJ 5101 type). In the drawing, 1 is a feeding reel, 2 is a tension control, 3.5, 6. R, 9゜] is a free roll, 4 is a tension detector (inlet),
Reference numeral 7 indicates a chrome-plated fixed bottle (5 baskets ψ), 10 a tension detector (outlet), 12 a guide a-ra, and 13 a take-up reel.

As shown in Part 1, in an atmosphere of 25°C and 60% RH, the film was passed through the film so that the coated surface was in contact with a fixed bottle K (152/180)π radian with an outer diameter of five directions, and at a speed of 33 cln/see. 9 Move and rub. Then, the exit tension T is obtained when the tension controller 2 is adjusted so that the input rotary tension y is equal to soP and 7'c.

(10) is obtained, and the dynamic friction coefficient μ is calculated using the following formula.

, az=o, 8681□Red 0 Note that the tape length to be detected was 89.1 to.

4. Film Friction Coefficient The friction coefficient between the coated surface and the polyester (untreated) film surface was measured using a slipper measuring device manufactured by Toyo Tester Co., Ltd.

5. Heat resistance (blocking test) diameter 1oom/
Using a small laminator consisting of two rubber rolls of 300 mm, the degree of blocking is determined after passing the films overlappingly at various temperatures.

& Magnetic paint was coated on the coated side of the adhesive laminate under specified conditions, and Scotch Tape Ro 600 (manufactured by Three M Company) was applied to a width of 19.4'! Adhesive with a + length of 80 m111, smoothed the top with a manual load roll as described in JIS-C2701 (1975), and applied head speed aoo+w between the laminated parts scR using Tensilon UM-III manufactured by Toyo Baldwin Co., Ltd. The sample was peeled off at a rate of 1/min, the peel strength at this time was determined, and this was divided by the tape width to determine 11/α.

[Adjustment of magnetic paint for evaluation]

Nitrocellulose R8I/2 for paint lacquer thinner
(Flakes containing 25% isopropanol, Daicel ■
A 40% by weight solution was prepared. The solution 43
．． 9 Heavy background part 1 Polyester resin (Desmophene #: 17
001 Bayer M) 325 parts by weight, 260 parts by weight of chromium dioxide magnetic powder, soybean oil fatty acid (Region P; manufactured by Buken Vitamin ■) as a button dispersant and wetting agent, cationic activator (Cation AB, NOF ■) ) and squalene (shark liver oil) respectively.
．． It was put into a ball mill with 8 radio waves. Furthermore, 282 parts by weight of a mixed solution consisting of methyl ethyl ketone (hereinafter abbreviated as MEK)/cyclohexanone/toluene = 3/4/s (weight ratio) was further mixed and optically pulverized to prepare a mother liquor paint (45% by weight). . Subsequently, 50 parts by weight of the mother liquor (K) 48 parts by weight of an addition reaction product of IJ methylolpropane and toluylene diisocyphate (Coronate L: manufactured by Nippon Polyurethane Industries) and 6.25 parts by weight of acetic acid slurry were added. They were added and mixed to finally obtain a magnetic paint for evaluation with a weight of 42.75%.

((a) An aqueous dispersion with a solid content of 18% by weight obtained by neutralizing the free carboxyl groups of isophthalic acid-sebacic acid-trimeric) acid-p,p'-diaminodiphenylmethane copolymerized polyamideimide with NH. was diluted with water to prepare an aqueous dispersion with a concentration of 2% by weight. Add 1000I of this solution to the 7-ionic surfactant polyoxyethylene thenyl phenyl ether (HLBI 2.8 nonionic NS 208.
A coating liquid (hereinafter referred to as coating liquid A) was prepared by adding 2 sg of an aqueous dispersion containing 20% by weight of silica (manufactured by Nippon Oil & Fats Corporation) and 20% by weight of silica having an average particle size of 15 fiμ to prepare a coating liquid (hereinafter referred to as coating liquid A).

(B) Terephthalic acid-adipic acid-trimellitic acid-5-Na sulfoiphthalic acid-1), P as an aqueous dispersion
The above (
A coating liquid (hereinafter referred to as coating liquid B) was prepared in the same manner as in (a).

(c) Instead of an aqueous dispersion, the free carboxyl groups of the isophthalic acid-trimellitic acid-1,6-hexamethylene diamine p,p'-diaminodiphenylmethane copolymerized polyamideimide are neutralized with an emulsifier. A coating liquid (hereinafter referred to as coating liquid C) was prepared in the same manner as in (4) above, except that the emulsion having a solid content of 18% by weight was used.

) Terephthalic acid - isophthalic acid - instead of aqueous dispersion
Same as above except that an aqueous solution of adivic acid-ethylene glycol-monoethanolamine-5-Na sulfoiphthal a-p=p'-diaminodiphenyl ether copolymerized polyester amide imide with a solid content of 18% by weight is used)
A coating liquid (hereinafter referred to as coating liquid) was prepared in the same manner as above.

(b) Production of laminated film Polyethylene terephthalate containing an inorganic fine filler with an intrinsic viscosity (measured in a 0-lower z/-r at 25°C) of 0.65 is melt-extruded on a rotating drum under pressure maintained at approximately 20'CK. An unstretched film of 158μ (microns) was obtained, which was then stretched 3.5 times in the machine direction.
The coating solution prepared in step 1 was coated on one side of a uniaxially stretched film using the kiss coating method. After that, the obtained film was passed through a preheating zone at 97°C, and then 3.9 times larger in the transverse direction at 4°C. It was extended to.

Subsequently, the biaxially stretched film was heat treated at 205°C for 4.3 seconds to form a film with a thickness of 12.2μ with an average coating amount of 1osq/y.
An axially oriented polyester film was obtained.

The various properties of this film are shown in Table 1.

Comparative example 1 The same procedure as in Example 1 was carried out except that the coating liquid was not poured into the chamber.

The properties of this base polyester film are also listed in Table 1. Adhesive strength, runnability, and slippage between films were poor.

Comparative Example 2 Examples 1 to 4 (
A coating solution (hereinafter referred to as coating solution E) was prepared in the same manner as in step a).

Using this coating liquid E, the same procedure as in Example 3 was carried out to obtain a biaxially stretched laminated polyester film. The results of determining the properties of this film are also listed in Table 1. Low heat resistance, 1
Blocking occurred at 00°C.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram for measuring the coefficient of dynamic friction for evaluating film runnability.

Claims (1)

[Claims] A method for producing a heat-resistant laminated film or sheet, which comprises applying an aqueous solution, emulsion or dispersion of.