JP3301493B2 - Laminated film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent antistatic film having excellent water resistance and solvent resistance.

[0002]

2. Description of the Related Art Conventionally, polyolefins, polyesters,
Films made of thermoplastic resins such as polyamide, polystyrene, and polyvinyl chloride, especially films of oriented polypropylene, polyester, and polyamide have excellent mechanical properties, heat resistance, transparency, and the like. Film, a substrate of a magnetic recording medium, a general industrial film, and the like. However, these films have the disadvantage that they are susceptible to electrification by static electricity because the resin itself is an insulator. Conventionally,
Various measures have been taken to impart antistatic properties to these films. For example, a surfactant having an antistatic property, an ionic compound, a conductive substance such as a metal powder or a metal oxide, or the like is kneaded into a film composition or blended into a coating material to form a film surface. Or the method of applying to the surface. However, the method using a surfactant and an ionic compound as the antistatic agent has a problem that the antistatic property is reduced under low humidity. On the other hand, the method using a conductive substance does not have a problem that the antistatic property is reduced even in an environment of low humidity, but it is necessary to add a large amount of a conductive substance to impart antistatic property, There is a problem that transparency is reduced.
In addition, there has been a problem that such a conductive substance is expensive. Therefore, development of a thermoplastic film which is transparent and has excellent antistatic properties has been demanded.

[0003]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a thermoplastic film having excellent antistatic properties, water resistance and solvent resistance at low humidity. To provide.

The laminated film of the present invention comprises, on at least one surface of a film made of a thermoplastic resin, a water-soluble or water-dispersible polymer having an active hydrogen and a quaternary nitrogen atom in a molecule, and a water-soluble or water-dispersible polymer. compositions containing at least one multifunctional blocked isocyanate compound Tona
A laminated film provided with a coating layer, wherein the coating layer is
A laminated film provided in a film manufacturing process .

[0005] The thermoplastic film used in the present invention is not particularly limited as long as it is a thermoplastic resin having a transparent film-forming ability. However, olefinic resins such as polyethylene and polypropylene, polyethylene phthalate, polyethylene isophthalate, polyethylene 2 , 6 naphthalate, polyester resin represented by polybutylene terephthalate and their copolymers, polyether resin represented by polyoxymethylene, nylon-6, nylon-6
6. Polyamide resin represented by polymeta-xylene adipamide, polystyrene, poly (meth) acrylate, polyacrylonitrile, polyvinyl acetate represented by polyvinyl acetate and copolymers thereof, and polycarbonate resin And cellulosic resins such as cellophane and acetate, as well as polyimide, polyetherimide, polyphenylene sulfide, polyether sulfone, polysulfone, polyether ketone, polyether ketone ketone, fluorine-containing polymers, and many other resins. This is a film composed of a simple substance, a copolymer, a mixture, and a laminate before the stretching and orientation treatments are completed.

[0006] polymer having active hydrogen and a quaternary nitrogen atom in the molecule of the present invention, be water-soluble or water-dispersible
is necessary. For example, polyesters having a hydrophilic group, acrylic polymers, vinyl polymers and the like can be mentioned. Examples of the active hydrogen include a hydroxyl group, an amino group, an amine group, and an organic acid group. Particularly preferably, the acrylic resin into which active hydrogen and quaternary nitrogen are easily introduced is preferable. The active hydrogen group includes a hydroxyl group, an amino group, and a carboxyl group that can react with an isocyanate group. Examples of the acrylic monomer having a hydroxyl group include 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate. Examples of the acrylic monomer having an amino group include 2-aminoethyl acrylate and 2-aminoethyl methacrylate. Examples of the acrylic monomer having a carboxyl group include acrylic acid and methacrylic acid. The acrylic monomer having a quaternary nitrogen includes, for example, a quaternary compound of dimethylaminoethyl acrylate, a quaternary product of dimethylaminoethyl methacrylate, a quaternary product of diethylaminoethyl acrylate, a quaternary product of diethylaminoethyl methacrylate, a quaternary product of methylethylaminoethyl acrylate, Examples thereof include quaternized methylethylaminoethyl methacrylate, quaternized dimethylaminostyrene, and quaternized methylethylaminostyrene, and one or more of these can be used. Other polymerizable monomers include alkyl acrylates such as methyl acrylate and ethyl acrylate, alkyl methacrylates such as methyl methacrylate and ethyl methacrylate, and vinyl monomers such as styrene, vinyl toluene and vinyl acetate. Is mentioned. The blocked isocyanate used in the present invention blocks an isocyanate having two or more isocyanate groups in a molecule, for example, a monomer such as tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate or a modified isocyanate group ( Water-soluble or water-dispersible blocked isocyanate exhibiting cationic or nonionic properties that has been masked. Oxime in addition to phenols,
Those such as lactams and malonic esters are used. This blocked isocyanate has an active isocyanate group from which a block is released by heating, and plays a role as a curing agent. The mixing ratio of the blocked isocyanate and the polymer is preferably 0.3 to 1.4, more preferably 0.6 to 1.1, the number of active hydrogen groups / the number of isocyanate groups.

When a coating film is formed by using the coating film forming composition of the present invention, an organic or inorganic metal salt such as a metal salt catalyst such as tin or titanium is used to promote a crosslinking reaction of the isocyanate compound. It is desirable to use a small amount of an organic or inorganic alkaline compound such as an amine, a polyamine, an amidoamine, a polyamidoamine, an imidazole, an alkali metal carbonate, or a cross-linking hardener composed of a derivative thereof. The solution for forming a coating film in the present invention is preferably used in an aqueous solution because the polymer is water-soluble, but may be used in combination with an organic solvent such as alcohol for the purpose of improving the wettability with polyester. good. Also, if necessary, further crosslinking agents, catalysts,
A paint or the like can be added. In addition, an ultraviolet absorber, a pigment, an organic filler, an inorganic filler, a lubricant, an anti-blocking agent and the like may be used in combination as long as the object of the present invention is not impaired. In addition, other binder resins may be used in combination to improve properties such as adhesion and blocking properties. The means for mixing when mixing and laminating multiple components is not limited, and a known method such as a high-speed stirring method, a high-pressure dispersion method, or an ultrasonic dispersion method can be arbitrarily used. A method combining these methods is also suitable.

As a method for laminating a solution of the composition thus obtained to the substrate film surface, a coating method of applying a solution or dispersion to a substrate film surface
Used in the film manufacturing process, ie, cast raw material or
Apply after uniaxial stretching, then dry, stretch and heat treat
Method. In particular, it is preferable to perform the stretching treatment in a state where the moisture content of the coating film after application is 20% or more after the cast raw material or the uniaxial stretching. A known method can be applied as a method of applying the coating layer on the base film. For example, a spray coat method, an air knife method, a river coat method, a kiss coat method, a gravure coat method, a Meyer bar method, a roll brush method, and the like can be applied. The coating amount of the aqueous solution of the coating film forming composition applied to the base film is 0.01 to 5 g / m ² as a solid content. If the coating amount is less than 0.01 g / m ² , sufficient antistatic properties cannot be obtained. Blocking is a problem when applied at 5 g / m ² or more.

By applying a corona discharge treatment to the base film before applying the solution of the above composition, the coatability of the solution is improved or the adhesion between the base film and the coating film is improved. Means can be adopted. The wettability and adhesiveness of the film surface can be improved by performing a corona discharge treatment, a corona discharge treatment in a nitrogen atmosphere, an ultraviolet irradiation treatment, or the like on the coated film layer after lamination.

[0010] The laminated film produced by the above method is particularly useful as a base material for magnetic recording media, for example, video tapes, audio tapes, computer tapes, floppy disks and the like. It is also useful as a substrate for general industrial films, such as membranes, telephone cards, labels, microfilms, diazo films, OHP films, and the like.

[0011]

Next, examples of the present invention and comparative examples will be described. The evaluation method used in the present invention is shown below. 1) Surface resistance Takeda Riken Co., Ltd. specific resistance measuring instrument applied voltage 500V, 2
The measurement was performed at 3 ° C. and 20% RH. 2) Evaluation of water resistance and solvent resistance The film was immersed in each solvent, and the surface resistance was measured after standing at room temperature (26 ° C) for 16 hours.

[0012]

Example 1 Methyl methacrylate / ethyl
Ruacrylate / 2-hydroxyethyl methacrylate
/ Dimethylaminoethyl methacrylate quat
Copolymerized in a ratio of 47/21/7/25 as a composition ratio.
Thus, a copolymer aqueous solution was obtained. Into this aqueous copolymer solution,
Elastron MF9 as a basic isocyanate compound
(Daiichi Kogyo Co., Ltd., nonionic)
15% by weight of C
at64 (Daiichi Kogyo Co., Ltd.)
The solid content is 7%
% Of the composition for forming a coating film. Intrinsic viscosity 0.65
Of polyethylene terephthalate at 280-300 ° C
Extruded, cooled with a cooling roll at 15 ° C,
Film at 85 ° C. with different peripheral speeds
After stretching 3.5 times in the longitudinal direction between a pair of rolls of
10 g of an aqueous solution of the composition for forming a coating film according to the kiss coat method.
/ M ^TwoApply and dry with hot air at 70 ° C, then tenter
Stretched 3.5 times in the transverse direction at 98 ° C.
100 μm thick biaxially stretched coating heat set at 10 ° C
A polyester film was obtained. Characteristics of the obtained film
The properties are shown in Table 2.

[0013]

Examples 2 to 5 The same procedures as in Example 1 were carried out except that the composition of the coating film forming composition was changed as shown in Table 1.

Examples 6 to 9 The same procedure as in Example 1 was carried out except that the base film and the coating film forming composition were changed as shown in Table 1 and the stretching and heat setting conditions were changed as appropriate.

[0014]

Comparative Examples 1 to 5 The same procedures as in Example 1 were carried out except that the composition of the coating film forming composition was changed as shown in Table 1.

COMPARATIVE EXAMPLE 6 A commercially available anionic antistatic agent comprising the resin (A) of Comparative Example 2 in Table 1 and sodium sulfonate was used in an amount of 8%.
Example 2 was carried out in the same manner as in Example 1 except that the mixed solution was used as a coating solution at a ratio of / 2.

[0015]

Comparative Example 7 The same procedure was performed except that the aqueous solution of the coating film forming composition of Example 1 was not applied. As shown in Table 2, the antistatic films of the examples have low surface resistance even at low humidity, have excellent antistatic properties, and have excellent water resistance and solvent resistance. On the other hand, in Comparative Example 1, the spreadability of the coating film was poor and a uniform coating film could not be formed, and the antistatic property could not be imparted. Comparative Examples 2 and 3 are inferior in antistatic properties. Comparative Example 4 is excellent in antistatic properties but inferior in water resistance and solvent resistance. In Comparative Example 5, the aqueous solution of the composition to be applied is aggregated and cannot be applied. Comparative Example 6 is inferior in antistatic properties at low humidity. Comparative Example 7 has no antistatic property at all.

[0016]

As described above, the antistatic film of the present invention has excellent antistatic properties at low humidity, and excellent water resistance and solvent resistance. It can be widely and suitably used for films and various packaging films.

[0017]

[Table 1]

[0018]

[Table 2]

──────────────────────────────────────────────────続 き Continuing on the front page (72) Mutsuyuki Kawaguchi 2-1-1 Katata, Otsu-shi, Shiga Toyo Spinning Co., Ltd. (72) Toshitake Suzuki 2-1-1 Katata, Otsu-shi, Shiga No. Examiner in the Research Laboratory of Toyobo Co., Ltd. Eiichi Yoshi ▼ (56) References JP-A-60-248745 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08J 7 / 04-7/06 B32B 27/00-27/42

Claims (1)

(57) [Claims] A water-soluble or water-dispersible polymer having active hydrogen and a quaternary nitrogen atom in a molecule on at least one surface of a film made of a thermoplastic resin, and a water-soluble or water- soluble polymer.
Laminate off having a dispersion coating layer comprising a composition comprising at least one multifunctional blocked isocyanate compound
Film, wherein the coating layer is provided during a film manufacturing process.
Laminated film characterized in that it is.