JPS6251443A - Polyester film laminate and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a polyester film laminate and a method for producing the same, and more particularly to highly processed products such as audio magnetic tape, video magnetic tape, and magnetic tape for funbutters. The present invention relates to a polyester film laminate having excellent adhesiveness and solvent resistance, useful as a base material for , 70 Tubi discs, X-ray photographic films, etc., and a method for producing the same.

PRIOR ART It is known to melt extrude and form films from thermoplastic polyesters, such as polyethylene terephthalate or its copolymers, polyethylene terephthalate or its copolymers, or blends of stiffness and small proportions of other resins. be. It is also known that the resulting two-wheel stretched and heat-set polyester film has better heat resistance, gas barrier properties, electrical properties, and chemical resistance than films made of other resins. However, since its surface is highly crystal oriented, it has a high cohesive property, making it difficult to paint, paint, etc.
Poor receptivity to adhesives, inks, etc.

Therefore, when a synthetic resin layer is provided on the surface of such a polyester film (1), in order to strengthen the adhesion between the two, the surface of the polyester film is activated by subjecting it to corona discharge treatment, ultraviolet irradiation treatment, plasma treatment, or flame treatment. And synthetic resin? ! ! A means of coating the membrane has been applied. However, although these methods of activating the film surface can be expected to improve adhesion to the coating layer by increasing the secondary bonding strength of the coating layer, the activity decreases over time. Therefore, these means of activating the film surface are not necessarily satisfactory.

As another method for increasing the receptivity of the polyester film surface, etching methods have been proposed in which the surface is swollen or partially dissolved with various agents. This involves etching the film surface by contacting it with chemicals such as acid, alkali, amine aqueous solution, trifluoroacetic acid, or phenols, decomposing, melting, and relaxing the crystal orientation near the surface, and at the same time reducing cohesion. binder 11 by lowering
1. It aims to improve the adhesion between Ill and Ill,
The effect is most reliable, and the adhesion between the film and the layer provided thereon, such as a synthetic resin coating layer, becomes strong. However, some of the chemicals used in this method are harmful and may be dangerous to handle, and there is a risk that volatile substances from the chemicals may be released into the atmosphere. There are various disadvantages from a practical point of view, such as the need to be careful.

As a method similar to this method, a primer layer (undercoat JriJ) is provided on the film surface in advance, a thin surface layer different from the base film is formed, and then a desired layer, such as a synthetic resin layer, is coated. be. When forming the undercoat layer, a coating treatment is usually performed in a process separate from the polyester film forming process. However, highly processed products such as audio magnetic tape, video magnetic tape, computer magnetic tape, etc.
In applications such as floppy disks, X-ray photographic films, and diazo microfilms where precision and delicate quality must be maintained, even if an easily adhesive surface is successfully formed, the resulting film may suffer from surface defects due to dust. If so, it cannot be used as a base film for these purposes, but this drawback is likely to occur in this separate process. Therefore, it is desirable to perform the undercoating process in an atmosphere as free from dust as possible. There is a polyester film forming process that satisfies these conditions, and if the lower MB treatment is performed in this process, a product that can be used as the above-mentioned advanced film processed product can be obtained.

On the other hand, in the prior art Vc6, the method of modifying the surface of a polyester film to an easily adhesive surface by treating the surface with a primer has been achieved in many cases by applying a composition dissolved in an organic solvent to the surface layer of the film. . If such a method is carried out during film production, the use of organic solvents should be kept to a minimum as much as possible, as the fugitive organic solvents may contaminate the environment, cause unfavorable safety and hygiene conditions, and have a negative impact on the film forming process. Should. Therefore, when performing in-line subbing treatment in the film forming process, it is preferable to use a composition using water as a solvent from the viewpoint of the process, economy, and safety. Therefore, many primer compositions using water as a solvent have been proposed, and many proposals have been made for aqueous solutions or dispersions of polyurethane or polyester.

For example, Japanese Patent Publication No. 46-10193 discloses the use of polyurethane having solvent resistance to acetone and water dispersibility.

However, these primer compositions swell or dissolve in solvents used in magnetic paints, such as methyl ethyl ketone, cyclohexanone, tetrahydrofuran, etc., and are insufficient in terms of solvent resistance. When a highly polar paint such as a magnetic paint is applied on a single layer of such Goofima, mixing of the primer layer and the magnetic layer occurs, which not only reduces the adhesion effect of the primer layer but also causes the coating to become difficult.
1. Flow streaks occur on the surface, making it impossible to obtain a good coating surface. Particularly in recent years, recording densities have been increasing in coated magnetic recording media, and magnetic layers are becoming thinner.

In particular, floppy disks have rapidly become thinner, and the thickness has decreased to about 1 pWL.

When the magnetic layer becomes thin like this, - the above-mentioned flow lines generated on the surface of the magnetic layer make it difficult to obtain a good magnetic surface <L, il! This is not preferable because it causes deterioration of magnetic conversion characteristics.

Object of the invention The object of the invention is to apply various coatings applied to polyester films, such as cellophane paints, gelatin compositions, offset inks, electrophotographic toners, chemical matte paints, azo paints, and heat-sealable coatings. A stable solvent-resistant agent that has excellent adhesion to coating compositions, inorganic film-forming substances, etc., does not cause wave removal streaks when coating these coatings, and is not affected by drying conditions of the coating solution. It is an object of the present invention to provide a polyester film laminate coated with a 75-ff-Mk coating having a property of 75%. Another object of the present invention is to provide a preferred method of manufacturing such polyester film laminates.

Structure of the Invention Such an object of the present invention is that, according to the present invention, at least the h side of the polyester film contains (1) a carboxylic acid group, a sulfonic acid group and at least 1 W of an ester base in an acid.
(1) carboxylic acid on at least one side of the polyester film before crystal orientation is completed; base.

Applying an aqueous climber coating solution containing an aqueous polyurethane having at least one of a sulfonic acid base and a sulfuric acid half ester base and (2) a polyvalent metal compound, and then drying, stretching, and heat treatment to complete crystal orientation. A method for producing a polyester film laminate characterized by:

In the present invention, polyester is a linear saturated polyester synthesized from an aromatic dibasic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof.

Specific examples of such polyesters include polyethylene terephthalate, polyethylene phthalate, polybutylene terephthalate, polywhite, 4-cyclohexylene dimethylene terephthalate), polyethylene-2,6-naphthalene dicarboxylate, and copolymers of these polyesters. Also included are blends of straw and a small proportion of other resins.

The polyester film of the present invention is obtained by melt-extruding such a linear saturated polyester resin, forming it into a film by a conventional method, and subjecting it to oriented crystallization and heat treatment crystallization. This polyester film is preferably one whose crystals are oriented to such an extent that the heat of crystal fusion measured by a scanning calorimeter in a nitrogen stream [at a heating rate of 10° C./min] usually exhibits a value of 4 cal/I or more. .

In the present invention, a polyester film before completion of crystal orientation refers to an unstretched film obtained by thermally melting the polymer and forming it into a film as it is; an unstretched film oriented in either the vertical direction or the horizontal direction. uniaxially stretched film; further K is a film that has been stretched and oriented at low magnification in both the vertical and horizontal directions (biaxially stretched film before being finally re-stretched in the vertical or horizontal direction to complete oriented crystallization) ) etc.

The aqueous primer coating liquid used in the present invention is (1)
(2) an aqueous polyurethane having at least 1 m of carboxylic acid groups, sulfonic acid groups and ester groups in sulfuric acid;
It contains a polyvalent metal compound.

This water-based polyurethane is a carboxylic acid base.

The affinity for water is increased by a sulfonic acid group or a sulfuric acid half ester base, and such an affinity-imparting group is usually introduced during or after polyurethane synthesis.

For example, the introduction of a carboxylic acid group can be carried out by using a carboxylic acid group-containing poly(e)'a-oxy compound as one of the raw material polyester doxy compounds during polyurethane synthesis, or by using a polyurethane containing unreacted incyanate groups. This can be carried out by reacting a hydroxyl group-containing carboxylic acid or an amino group-containing carboxylic acid with a carboxylic acid, and then adding the reaction product to an alkaline aqueous solution under high-speed stirring to neutralize it. In addition, the introduction of a sulfonic acid group or a sulfuric acid half-ester group is usually carried out by forming a polymer from a polyhydroxy compound, a polyisocyanate, and a chain lengthening agent, and then adding an amino group or a hydroxyl group that can react with the terminal incyanate group and a sulfonic acid group or a sulfonic acid group. A compound having a sulfuric acid half ester base in the molecule is added and reacted, and finally an aqueous compound having an rc sulfonic acid group or a sulfuric acid half ester base in the molecule is added.
This can be done by obtaining polyurethane. That l
It is preferable that the @formation reaction is carried out in an organic solvent, then water is added and then the solvent is removed. Another method is to synthesize a polyurethane having a sulfonic acid group using a compound having a sulfonic acid group as one of the raw materials, and then add the polyurethane to an alkaline aqueous solution under high speed stirring to neutralize it. , a method in which the following sultone compound is added to the primary or secondary 7-mino group of the main chain or side chain of polyurethane in the presence of an alkali to introduce an alkali sulfonic acid salt (e.g. -8O, Na, etc.). can give. As the aqueous alkali solution, it is preferable to use an aqueous solution of sodium hydroxide, potassium hydroxide, ammonia, furkylamine, etc., but the alkali does not remain in the coating (undercoating film) and the amine that evaporates under drying conditions is preferable. Particularly preferred. Carboxylic acid base.

The amount of bases such as sulfonic acid bases and sulfuric acid half ester bases is 0.
．． 5 to 15% by weight is preferred. If the proportion of the base is too small, the water affinity of the polyurethane will be insufficient, making it difficult to prepare a coating solution, and if it is too large, the inherent properties of the polyurethane will be impaired, which is not preferable. Such aqueous polyurethanes are those that form stable aqueous dispersions or solutions using polydispersion aids if desired.

Polyhydroxy compounds used in the synthesis of polyurethane include, for example, polyethylene glycol, polypropylene glycol, polyethylene/propylene glycol, polytetramethylene glycol, and hexamethylene glycol.
lunatetramethylene glycol, l,5-bentanediol, diethylene glycol, triethylene glycol, polycaprolactone.

Polyhexamethylene 7 diphate, polyhexamethylene sepacate, polytetramethylene 7 dihate, polytetramethylene sebacate.

Trimethylolpropane, trimethylolethane, pentaerythritol, glycerin, etc. can be mentioned. Examples of polyisocyanate compounds include hexamethylene diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, inhorn diisocyanate, and adducts of tolylene diisocyanate and trimethylolpropane.

Examples include adducts of hexamethylene diisocyanate and trimethyl ethane. Examples of carboxylic acid-containing polyols include dimethylol bupionic acid,
Examples include dimethylolbutyric acid-dimethylp-valeric acid, trimellitic acid bis(ethylene glycol) ester, and the like. As the amino group-containing carboxylic acid, 1, for example, β
-Amitubu p-pionic acid-r-7minobutyric acid, P-ami, nobenzoic acid, etc. can be mentioned. As the hydroxyl group-containing carboxylic acid, for example, 3-droxypropionic acid.

γ-Hydroxybutyric acid + P -(2e dotetraxyethyl)
Examples include benzoic acid and malic acid. Examples of compounds having an amino group or a hydroxyl group and a sulfonic group include 7-minomethanesulfonic acid, 2-7-minoethanesulfonic acid, 2-amino-5-methylbenzene-2-sulfonic acid, and β-droxyethanesulfonic acid. Examples include propane sultone and butane sultone adducts of sodium, aliphatic di-primary amine compounds, etc. Preferably, propane sultone adducts of aliphatic di-primary amine compounds are mentioned. Furthermore, examples of compounds containing a 7-mino group or a hydroxyl group and a sulfuric acid half-ester group include aminoethanol sulfuric acid,
Ethylenediamine ethanol sulfate, aminobutanol sulfate tL droxyethanol sulfate, r-hydroxypropanol 5! and α-hydroxybutanol sulfate.

Polyurethane can be synthesized using these compounds by conventionally well-known methods.

Examples of the polyvalent metal compound to be reacted with the aqueous polyurethane include divalent or higher metal hydroxides, oxides, inorganic chlorides, organic chlorides, chelate compounds, and the like. More specifically.

For example, Ba(OH)*l Ca(OH)s*An
(OH)s9ZrOmBaC1@*CaCJl*
ZnCJ* t AJCJI lFeC1* tZn
Inorganic metal compounds such as (NOs)s, organic acid polyvalent metal salts such as zinc acetate, tetra-n-butyl titanate, tetrastearyl titanate.

T i (OH) s (QCH(CHs) COOH
) organic titanium compounds such as s, tetraethyl silicate,
Organosilicon compounds such as tetrabutyl silicate; organoaluminum compounds such as aluminum isopropylate and aluminum-n-butyrate.

Zirconium compounds such as tetraethylzirconate, tetra-1-butylzirconate* (NH4)*ZrO(Cow)g, boric acid trimethyl ester, boric acid tolu-propyl ester, boric acid) +7- n-
Examples include boron compounds such as butyl ester. Among these, #tC organometallic compounds are preferred.

The aqueous primer coating liquid used in the present invention may be an aqueous solution or an aqueous dispersion. It is not limited to #. The ratio of aqueous polyurethane to polyvalent metal compound is 0.1 to 100% by weight of the latter to VC.
Parts by weight are preferred. If the proportion of the polyvalent metal compound becomes too large, the adhesion properties will be reduced and the stability of the coating solution will be reduced. -1 If the amount is too low, the solvent resistance will decrease and it will be difficult to obtain a good coated surface when the coating, which is the object of the present invention, is applied, which is not preferable.

The aqueous primer coating solution is made by dissolving or dispersing the above two components in an aqueous medium, but it can also be used by adding a necessary amount of a surfactant such as an anionic surfactant or a nonionic surfactant. . Such surfactants are preferably those that can lower the surface tension of the aqueous coating solution to 40 dyne/a or less and promote wetting to the polyester film, such as polyoxyethylene furkylphenyl ether, polyoxyethylene fatty acid ester, Sorbikun fatty acid ester, glycerin fatty acid ester.

Examples include fatty acid metal soaps, alkyl sulfates, alkyl sulfonates, alkyl sulfonates, and alkyl sulfonophosphates. Furthermore, antistatic agents, ultraviolet absorbers, gland absorbers, etc. may be used within the range that does not impair the effects of the present invention.

Pigment, organic filler, inorganic filler 9 Lubricating cutting.

Other additives such as antiblocking agents can be mixed.

The aqueous primer coating solution may be applied to the polyester film in a normal coating process, that is, in a process of coating the biaxially stretched and heat-set polyester film separately from one culm of the tablet film. However, in the process with.

Coating in a clean atmosphere is recommended for highly sophisticated products such as magnetic tape and 7A discs, as they tend to attract dust.

From this point of view, it is preferable to use a polyester film and apply it during the '4 step. In particular, it is preferable to apply an aqueous primer coating liquid to one or both sides of the polyester film before the dipping crystal orientation is completed during this step. In this case, the solid content concentration of the aqueous primer coating liquid is usually 30% by weight or less, more preferably 10% by weight or less. Is the amount of coating film lry? 0.5~20S per hit,
Furthermore, 1 to x01b'' - preferred. As the coating method, any known coating method can be applied. For example, - single coating method, gravure foot method, roll plush method, spray coating, air knife coating, impregnation method, and curtain method. It is recommended to apply a coating method alone or in combination.

The polyester film coated with the water-based coating solution is dried and then subjected to processes such as stretching and heat setting. For example, a longitudinally stretched polyester film coated with an aqueous primer coating solution is guided through a stenter, then laterally stretched and heat-set.

During this time, the coating solution dries and further undergoes a crosslinking reaction, forming a continuous film on the film. The crosslinking reaction is usually supplied by heat during elongation or heat setting. For example, this is 2
Heating at 00°C for about 10 seconds, 150°C for about 1 minute, 100°C for about 15 minutes, 220°C for about 8 seconds, etc., or under harsher or milder conditions. You may do so. In addition, the Reifu liquid was heated at 100°C for about 5 seconds for 11
About 5 seconds at 0℃.

It may be heated at 90°C for about 20 seconds. It may also be air-dried.

Oriented crystallization conditions for polyester film.

For example, the conditions for stretching, heat setting, etc.
This can be done under Fff conditions.

Effects of the Invention The thus obtained polyester film with a primer layer can be applied to an extremely wide range of paints such as cellophane inks, magnetic memory materials, gelatin targets, toner compositions for electrophotography, and chemical matte paints. shows high adhesion,
And methylethyl? Reketone, toluene, ethyl acetate, butyl acetate, ethanol, dioxane.

Shows excellent solvent resistance to ta-containing solvents such as detrahydrofuran, cyclohexanone, and cyclohexane.

example The present invention will be further explained below with reference to Examples.

Note that "parts" in the examples mean "parts by weight."

In addition, each bamboo property of the film was measured by the following method.

1. Apply the evaluation paint to the adhesive primer-coated polyester film, dry it at 80℃ for 1 minute, and then dry it at 60℃ for 24 hours.
After aging for several hours, roll coat is applied to an average coating thickness of 21 #xK. The resulting coated film is RCAjl! Wear □Head load fi50 using tester (RCA). The adhesion is measured by the number of times it wears until a hole forms on the cloth surface.

[Adjustment of paint for evaluation]

Nido p cell ps R81/2 for lacquer thinner for m1 type
(Flakes containing 25% iso1p bar/-bar: manufactured by Daicel ■) were melted and scaled.

A 40wt% solution was prepared, and 43.9 parts of this solution was added, followed by 32.5 parts of Polynisnar Nanzukiji (Desmofene≠1700: manufactured by Bayer AG), 2.60 parts of sodium dioxide pm magnetic powder, 1 dispersion, As a wetting agent, soybean oil and fat acid preventive agent (Region P: manufactured by Riken Vitamin (Structure), cationic activator (Cation AB)
1 each of squalene (made by Nippon Oil & Fats) and squalene (shark liver oil)
part, 0.5 part and 0.8 part into a ball mill.

282 parts of a heated solution consisting of methyl ethyl ketone (hereinafter abbreviated as MEK)/cyclohexanone/toluene = 3/4/3 (weight ratio) is further mixed and sufficiently pulverized to adjust the mother liquor paint (4s vt%) ft. To 50 parts of the mother liquor, 48 parts of an addition reaction product of trimethylolpropane and tolylene diinocyanate (Coronate Nippon Polyurethane Industry A magnetic charge for evaluation of .75 wj% was obtained.

Z, M Solvent-based Brimer Layer-treated Polyester Film
e) Place gauze on it, place a yKtoog weight on it, and move the gauze at a speed of about t000 m/min.

After drying at room temperature.

The interference loss residual photographs of those not treated with detrahydride q-furan and those treated with detrahydride q-furan were compared at 400 times magnification, and the state of surface change of the primer was judged as follows.

Those with almost no primer; x primer〇 Those with almost no change 20 Those with one minute change in surface shape in the middle: O ~ Δ Those with a considerable change in surface morphology: × ~ with an intermediate change in surface morphology Example 1 Polyurethane aqueous dispersion with carboxylic amine base [
Manufactured by Toyo Polymer ■: Product name Merci-585) 87 parts (
As a non-I component: 1. Polyoxyethylene sononylphenyl ether (manufactured by NOF ■: product name NS-240) 10
and (NH4)tZro(COs)z 3M were diluted with ion-exchanged water to prepare an aqueous primer coating solution with a solid content concentration of 4% by weight.

This coating solution was applied to a biaxially stretched polyethylene terephthalate film by gravure coating, and then 140'
A heat treatment was carried out for 45 seconds in the drying zone of C to obtain a polyester film laminate coated with one limer and one coated with an average coating weight of 50,119/- (dry).

The film laminate had sufficient adhesion to the magnetic paint for evaluation, and was able to form a good painted surface without running streaks.

Example 2 Informally determined lN viscous i in 0-liog roughenol at 25°C
o, 65 polyethylene terephthalate (containing lubricant) was melt-extruded onto a rotating cooling drum with a temperature of 1 m at 20°C to obtain an unstretched film with a thickness of 950 μm, and then subjected to a machine fJIi.
After stretching 3.5 times in the axial direction, the same coating solution as the coating solution prepared in Example 1 was applied to both sides of the -J11 stretched film using the kiss boat method.The average coating amount at this time was 50 η/d in terms of solid content.Subsequently, it was stretched 3.9 times in the transverse direction at 105°C and further heat treated at 210°C to obtain a 75 μm thick biaxially oriented polyester film laminate coated with primer on both sides. .

Examples 3 and 4 Ba(O) instead of the zirconium compound in Example 2
(Example 3) or Ti(OH)*COCH(C
A polyester film ff1i was obtained in exactly the same manner as in Example 2 except that 11m) coou: + 2 (Example 4) was used.

Example 5 The same machine as in Example 2 was used except that a polyurethane aaC containing carbo/acid amine base was used instead of the coating solution in Example 2. A polyester film laminate was obtained.

Comparative Example 1 For comparison purposes, various evaluations were conducted using a polyethylene terephthalate film with a thickness of 75 μm that was not subjected to primer treatment.

Comparative Example 2 A polyester laminate was obtained in exactly the same manner as in Example 2, except that the zirconium compound in the coating solution of Example 2 was not used.

Adhesion and solvent resistance of the polyester film laminates obtained in Examples 1 to 5 and Comparative Examples 1 to 2.

Table 1 also shows the results of evaluating the stability of the coating solution when stored at 40°C for one month.

Table 1 It is clear from Table 1 that the single layer of limer in the film laminate of the present invention has excellent performance in solvent resistance and adhesion, and enables uniform and stable coating.

Claims (1)

[Scope of Claims] 1. On at least one side of the polyester film, (1) an aqueous polyurethane having at least one of a carboxylic acid group, a sulfonic acid group, and a sulfuric acid half-ester base, and (2) a polyvalent metal compound. A polyester film laminate with a reacted primer layer. 2. The laminate according to claim 1, wherein the polyvalent metal compound is an organometallic compound. 3. The laminate according to claim 1, wherein the base of the aqueous polyurethane is an amine base. 4. The laminate according to claim 3, wherein the amine base is a carboxylic acid amine base. 5. On at least one side of the polyester film before crystal orientation is completed, (1) an aqueous polyurethane having at least one of a carboxylic acid group, a sulfonic acid group, and a sulfuric acid half-ester base and (2) a polyvalent metal compound are applied. 1. A method for producing a polyester film laminate, which comprises applying an aqueous primer coating solution containing a polyester film, followed by drying, stretching, and heat treatment to complete crystal orientation. 6. The manufacturing method according to claim 5, wherein the polyvalent metal compound is an organometallic compound. 7. The manufacturing method according to claim 5, wherein the base of the aqueous polyurethane is an amine base. 8. The manufacturing method according to claim 7, wherein the amine base is a carboxylic acid amine base.