JPH08332706A - Layered film - Google Patents

Abstract

PURPOSE: To provide a layered film which can improve solvent resistance and blocking resistance and has excellent adhesion ability. CONSTITUTION: Water-coating liquid containing a composition whose main constituents are easy-to-adhere resin (A) (100 parts weight) of at least one type selected from a group consisting of resin and acryl denatured polyester resin and a carbodiimide series compound (B) (1-35 parts weight) is applied to at least single surface of polyester film, and easy-to-adhere coating film formed by heat treatment after drying and drawing is fitted onto it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated film, and more particularly to at least one side of a polyester film,
Magnetic cards, magnetic tapes, magnetic disks, graphic materials, electronic materials, membrane films, printer ribbons, processes that have an easily adherent coating film that has excellent adhesion to inks and paints, solvent resistance, and blocking resistance. The present invention relates to a laminated film useful as a material, a packaging material and the like.

[0002]

2. Description of the Related Art Polyester films, especially those made of polyethylene terephthalate or polyethylene naphthalate, are widely used for magnetic recording materials such as magnetic tapes and general industrial materials such as packaging materials, photographic materials and graphic materials. ing.

Since such polyester film has poor adhesion to inks and paints, a method is usually adopted in which an easily adhesive coating film is laminated on the surface and inks and paints are adhered onto this coating film. ing. However, conventional easily-adhesive coating films have poor solvent resistance, and therefore have the drawbacks that the coating films are dissolved or swelled by the solvent used in the ink or paint. Many coatings have been proposed in order to improve such drawbacks. For example, an easily-adhesive coating film applied using a coating liquid containing a crosslinking agent such as an isocyanate compound, a melamine compound, an epoxy compound, and a methylol compound is known. However, since a coating liquid containing such a cross-linking agent is difficult to use as an aqueous coating liquid, there are problems in disaster prevention and environmental protection, and the quality of the coating liquid deteriorates in a short time during storage as a coating liquid. There is a problem such as. Further, a film having a conventional easy-adhesive coating film laminated thereon has a drawback that it is difficult to wind the film into a roll because the coating film is easily blocked.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems of the prior art, improve solvent resistance and blocking resistance, and provide a laminated film having excellent adhesiveness.

[0005]

The object of the present invention is, according to the invention, to at least one side of a polyester film,
Composition containing 100 parts by weight of at least one easily adhesive resin (A) selected from the group consisting of polyester resin, acrylic resin and acrylic modified polyester resin, and 1 to 35 parts by weight of carbodiimide compound (B) as main components. This is achieved by a laminated film provided with an easily-adhesive coating film prepared by applying an aqueous coating solution containing a product, drying, stretching, and then heat treatment. Hereinafter, the present invention will be described in detail.

[Base Film] In the present invention, a polyester film is used as the base film, and the polyester constituting the base film is a linear polyester composed of a dicarboxylic acid component and a glycol component.

Examples of the dicarboxylic acid component include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, hexahydroterephthalic acid, 4,4'-diphenyldicarboxylic acid, adipic acid, sebacic acid and dodecanedicarboxylic acid. Among them, terephthalic acid and 2,6-naphthalenedicarboxylic acid are particularly preferable.

As the glycol component, for example, ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, cyclohexanedimethanol, polyethylene glycol. And the like, and ethylene glycol is particularly preferable.

Among such polyesters, a homopolymer of polyethylene terephthalate or polyethylene-2,6-naphthalate has excellent mechanical properties such as a high Young's modulus, and thermal properties such as good heat resistance and dimensional stability. It is preferable because an excellent film can be obtained.

The above-mentioned polyester may be a polyester obtained by copolymerizing the above-mentioned dicarboxylic acid component or glycol component in order to improve the adhesion between the polyester film and the easily adhesive coating. Further, a polyester obtained by copolymerizing a trifunctional or higher polyvalent compound in a small amount within a range in which the polyester is substantially linear (for example, 5 mol% or less) may be used.

The polyester can be produced by a conventional method. Also, the intrinsic viscosity of polyester is 0.45
The above is preferable because mechanical properties such as high rigidity of the film are improved.

The above polyester has a mean particle size of 0.1 as a lubricant in order to make the film slippery.
It is preferable to add organic or inorganic fine particles of about 01 to 20 μm at a blending ratio of, for example, 0.005 to 20% by weight. Specific examples of such fine particles include inorganic fine particles such as silica, alumina, calcium carbonate, titanium oxide, barium sulfate, kaolin, and carbon black, silicone resin, melamine resin, polystyrene resin, crosslinked polystyrene resin, acrylic resin, crosslinked acrylic resin, etc. The organic fine particles and the like can be preferably mentioned.

In addition to the above-mentioned fine particles, an antioxidant, an antistatic agent, a colorant, a pigment, a fluorescent whitening agent, a cross-linking agent, an ultraviolet absorber and the like can be added if necessary.

The polyester film used in the present invention is
It can be manufactured by a conventionally known method. For example, the polyester is melted and cast on a cooling drum to obtain an unstretched film, and then the unstretched film is stretched in the machine direction by 2 to 7 times, and then in the transverse direction by 1.1 to 8 times. Can be manufactured. If necessary, the vertical direction and /
Alternatively, it can be stretched again in the transverse direction. Further, it is possible to complete the oriented crystallization by heat treatment after stretching. The stretching temperature is preferably higher than the second-order transition point (Tg) of polyester. Further, the heat treatment temperature is 150 to 2
When the temperature is 70 ° C., the carbodiimide compound and the carboxyl group or the carboxyl group in the molecule of the polyester resin, the acrylic resin and / or the acrylic modified polyester resin sufficiently react with each other, and the solvent resistance and resistance of the easily adhesive coating film are improved. It is preferable because the blocking property becomes good. The thickness of the polyester film is 2 to 300 μm after stretching,
It is particularly preferably 4 to 260 μm.

[Easily Adhesive Resin (A)] The easily adhesive resin (A) used in the present invention is at least one resin selected from the group consisting of polyester resins, acrylic resins and acrylic modified polyester resins.

The polyester resin is a linear polyester composed of a polycarboxylic acid component and a polyhydroxy component. Examples of the polycarboxylic acid component include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, hexahydroterephthalic acid, 4.4'-diphenyldicarboxylic acid, adipic acid, sebacic acid, dodecanedicarboxylic acid, and trimellitate. Acid, trimesic acid, pyromellitic acid, 5-Na sulfoisophthalic acid, etc. can be mentioned. Examples of the polyhydric hydroxy component include ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, cyclohexanedimethanol, polyethylene glycol. , Glycerin, trimethylolpropane, pentaerythritol, dimethylolpropionic acid and the like.

The polyvalent carboxylic acid component or the polyvalent hydroxy component may be a dicarboxylic acid compound having one or more functional groups in the molecule, or a glycol compound. Such a polyester resin can be prepared by a conventional method, and it is preferable that the average molecular weight is 7,000 or more because the easily-adhesive coating film has good stretchability.

The acrylic resin is an acrylic copolymer obtained by polymerizing an acrylic acid ester monomer. Examples of the acrylic acid ester-based monomer include methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, ethyl crotonic acid, glycidyl methacrylate,
2-hydroxyethyl acrylate, 2-ethylhexyl acrylate, etc. can be mentioned.

This acrylic copolymer comprises at least one of the above acrylic acid ester monomers and acrylamide, methacrylamide, acrylic acid, methacrylic acid, sodium acrylate, potassium methacrylate, ammonium acrylate, N- It may be a copolymer obtained by polymerizing an acrylic acid-based monomer such as methylol acrylamide or N-methoxymethyl acrylamide.

In addition to the above, monomers such as vinyl chloride, vinyl acetate, styrene, vinyl ether, butadiene, isoprene, and sodium vinyl sulfonate can be used as a copolymerization component in the acrylic copolymer.

The acrylic copolymer includes acrylate component, methacrylate component, acrylic acid component, acrylamide component, 2-hydroxyethyl acrylate component,
It is preferable that a hydrophilic component such as an N-methylol acrylamide component be contained as a copolymerization component because the dispersibility and solubility in the aqueous coating solution will be good. Further, it may be a copolymer having a functional group in the side chain of the molecule. The average molecular weight of the acrylic copolymer is 4,000 to 1,000,
It is preferably 000.

The acrylic modified polyester resin is a modified copolymer obtained by polymerizing the above-mentioned polyester resin with the above-mentioned acrylic acid ester-based monomer and / or acrylic acid-based monomer. For example, it can be obtained by graft-polymerizing the above-mentioned acrylic acid ester-based monomer and / or acrylic acid-based monomer onto a polyester resin in an aqueous liquid using a radical initiator. This modified copolymer may have a functional group on the side chain of the molecule. The average molecular weight of the modified copolymer is 8,000 to 200,
It is preferably 000.

As the easily adhesive resin used in the present invention, one kind of resin selected from the above-mentioned polyester resin, acrylic resin and acryl-modified polyester resin may be used alone, or two or more kinds of resins may be mixed and used. It can also be used.

The easy-adhesive resin (A) may be a resin other than the easy-adhesive resin (A), such as polyurethane resin, epoxy resin or vinyl resin, in order to adjust the adhesiveness of the easy-adhesive coating film. A small amount (10% by weight or less) of resin, polyether resin, water-soluble resin or the like may be blended.

[Carbodiimide compound (B)] The carbodiimide compound (B) in the present invention is a compound represented by the following general formula (I).

[0026]

Embedded image R ¹ N = C = NR ² (Formula (I)) In the above formula (I), R ¹ and R ² are independently or simultaneously represented by the following elements or groups.

That is, R¹And R²Is a hydrogen element (-H),
Hydrocarbon group having 1 to 40 carbon atoms (-R ³: Carbon number 1-40
Aliphatic hydrocarbon group, alicyclic hydrocarbon group or aromatic carbon
Hydrogenated group), hydroxyl group (-OH), having hydroxyl group at the end
Group (-R^FourOH: R^FourIs a divalent hydrocarbon having 1 to 20 carbon atoms
Base, hereinafter R^FourThe same shall apply to. ), An alkoxy group
(-OR^Five: R^FiveIs a hydrocarbon group having 1 to 20 carbon atoms,
R^FiveThe same shall apply to. ), An alcoholate group (-R^Four
OM¹: M¹Is a monovalent metal element, and hereinafter M¹As for
And ), A carboxyl group (-COOH), and a terminal
A group having a ruboxyl group (-R^FourCOOH)
A group having a ruboxyl base (-R^FourCOOM²: M²Is
Alkali metal element, quaternary amine or alkyl phospho
N, below M²The same shall apply to. ),Sulfonic acid
Group (-SO₃H), a group having a sulfonic acid group at the terminal (-
R^FourSO₃H), sulfonate group (-SO₃M²), The end
A group having a sulfonate group at the end (-R^FourSO₃M²),
Acyl group (-COR^Five), A group having an acyl group at the end
(-R^FourCOR^Five), An ester group (-COOR^Five), The end
A group having an ester group at the end (-R^FourCOOR^Five, -NH
COOR^FiveOr -R ^FourNHCOOR^Five), -NR^FiveR
⁶A group represented by (R⁶: Is a hydrocarbon having 1 to 20 carbon atoms
Group, hereinafter R⁶The same shall apply to. ), -NR at the end^Five
R⁶A group having a group represented by (-R^FourNR^FiveR⁶, -C
ONR^FiveR⁶Or -R^FourCONR^FiveR⁶), Amino group
(-NH₂), A group having an amino group at the terminal (-R^FourNH
₂), A carbamoyl group (-CONH₂), Carba at the end
A group having a moyl group (-R^FourCONH₂Or -R^FourN
HCONH₂), Part of the hydrogen element of the carbamoyl group or
Is a group (-R^FourCON
HCH₂OH, -R^FourCONHCH₂OR^Five, -R^FourC
ON (CH₂OH)₂Or -R^FourCON (CH₂OR
^Five)₂), A halogen group (-F, -Cl, -Br,-)
I), R^FivePart of the hydrogen element of
Group, mercapto group (-SH), hydrogen source of mercapto group
A group in which an element is replaced by a hydrocarbon (-SR^Five), Iso at the end
A group having a cyanate group (-R^FourNCO) or at the end
A group having an oxirane group (group represented by the following formula (II))
Is.

[0028]

Embedded image

Examples of the carbodiimide compound include the following compounds.

[0030]

CH ₃ N = C = NCH ₃ (I-1) C ₆ H ₅ N = C = NC ₆ H ₅ (I-2) NaOC ₂ H ₄ N = C = NC ₂ H ₄ ONa ...... (I-3) C 5 H 11 N = C = NC 5 H 11 ...... (I-4) NaO 3 SC 2 H 4 N = C = NC 2 H 4 SO 3 Na ... (I-5) _{NaOCOC 2 H 4 N = C =} NC 2 H 4 COONa ... (I-6) in addition, -C ₆ H ₅ by the formula (I-2) represents a phenyl group.

[Easy-adhesive coating film] The easily-adhesive coating film in the present invention comprises 100 parts by weight of the easily-adhesive resin (A) and 1 to 35 parts by weight of the carbodiimide compound (B), preferably 3 to.
It is prepared by applying an aqueous coating solution containing a composition containing 25 parts by weight as a main component, drying, stretching, and then heat treatment. If the blending amount of the carbodiimide compound (B) is less than 1 part by weight, the solvent resistance of the easily adhesive coating film is insufficient, and if it exceeds 35 parts by weight, the adhesiveness is lowered.

The above composition has an average particle diameter of 0.0 as a lubricant in order to improve the slipperiness of the easily adhesive coating.
Inorganic or organic fine particles having a size of about 1 to 20 μm are used, for example,
It can be contained in a blending ratio of 001 to 5% by weight. Specific examples of such fine particles include silica, alumina,
Inorganic fine particles such as titanium oxide, carbon black, kaolin, and calcium carbonate, organic fine particles such as polystyrene resin, crosslinked polystyrene resin, acrylic resin, crosslinked acrylic resin, melamine resin particles, silicone resin, fluororesin, urea resin, and benzoguanamine resin are preferable. Can be mentioned. The organic fine particles may be a thermoplastic resin or a thermosetting resin as long as they are resins capable of maintaining the state of fine particles in the coating film, and are crosslinked with a degree of crosslinking according to the purpose. It may be a resin.

In addition to the above fine particles, surfactants, antioxidants, colorants, pigments, optical brighteners, plasticizers, other crosslinking agents,
Organic lubricants (slipping agents), ultraviolet absorbers, antistatic agents and the like can be added as required.

[Aqueous Coating Solution] In the present invention, an easily adhesive coating film is applied using an aqueous coating solution containing the above composition.
The solid content concentration of the aqueous coating liquid is preferably 1 to 30% by weight, and particularly preferably 2 to 20% by weight. When the solid content concentration is within this range, the viscosity of the aqueous coating liquid becomes suitable for coating. The aqueous coating solution used in the present invention can be used in any form such as an aqueous solution, an aqueous dispersion, and an emulsion. Further, the aqueous coating liquid may contain a small amount of solvent.

[Coating of Coating Film] In the present invention, the easily adhesive coating film is coated by coating the above-mentioned aqueous coating solution on at least one side of the polyester film, drying and stretching, and then heat treating. As the coating method of the aqueous coating liquid, any known coating method can be applied, for example, a gravure coating method, a reverse roll coating method, a die coating method, a kiss coating method, a reverse kiss coating method, an offset gravure coating method, a Meyer bar coating method. The roll brush method, spray coating method, air knife coating method, impregnation method, curtain coating method and the like can be applied alone or in combination. The WET coating amount of the aqueous coating liquid is preferably 1 to 40 g, particularly ^{2 to 20} g per 1 m ² of the running film. When the coating amount is in this range, drying is easy and coating spots are less likely to occur, which is preferable.

The film to which the aqueous coating solution is applied in the present invention is
Stretchable polyester film, for example, unstretched film obtained by heat-melting polyester to form a film as it is; uniaxially stretched unstretched film in either longitudinal direction (longitudinal direction) or transverse direction (width direction) Stretched film; biaxially stretched film obtained by sequentially stretching a uniaxially stretched film in the longitudinal direction or the transverse direction in the transverse direction or in the longitudinal direction (which can be further stretched), or simultaneously stretching an unstretched film in both the longitudinal and transverse directions. A biaxially stretched film (which can be stretched further) can be mentioned.

The easily-adhesive coating film can be applied by applying an aqueous coating solution, drying and stretching, and if necessary, further re-stretching in the machine direction or the transverse direction and heat-treating. The heat treatment temperature is preferably 150 to 270 ° C, particularly 180 to 250 ° C. When the heat treatment temperature is less than 150 ° C,
If the carbodiimide compound and the polyester resin, the acrylic resin and / or the acrylic modified polyester resin react with the carboxyl group or the carboxyl group in the molecule, the crosslinking may be insufficient, and if the temperature exceeds 270 ° C, the base film is thermally deteriorated. As a result, the film characteristics may deteriorate.

The thickness of the easily adhesive coating is 0.01 to 1 μm.
m, particularly preferably 0.02 to 0.6 μm.
If the coating film thickness is less than 0.01 μm, the adhesiveness may be insufficient, and if it exceeds 1 μm, the coating film surface may be roughened or easily scraped.

[0039]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. Each characteristic value was measured by the following method. The average molecular weight in the examples means the number average molecular weight.

1. Adhesiveness (Ink Adhesiveness) A resist ink containing a terminal bisacrylic polyurethane oligomer, a photopolymerization initiator, a photosensitizer and a colorant is applied to the coating surface of the film to a thickness of 8 μm and cured by irradiating ultraviolet rays. I made an ink film. Next, cellophane tape was attached to the coated surface and then peeled off, and the adhesiveness was evaluated from the peeled state as follows. A: Peeling occurred between the cellophane tape and the ink film. (Good adhesion) B: The ink film was peeled off in a state of partial cohesive failure. (Slightly good adhesiveness) C: Peeled between the film and the ink film. (Poor adhesion)

2. Solvent resistance Rubbing the surface (blank sample) of the polyester film not coated with the coating film and the coated surface (evaluation sample) of the film coated with the coating film with a cotton swab moistened with the solvent for 15 seconds, After wiping, the coated surface was dyed and the degree of coloring was compared and observed, and the solvent resistance of the evaluation sample was evaluated as follows. A mixed solvent of methyl ethyl ketone, toluene and cyclohexanone was used as the solvent. A: The coloring degree was almost the same as that of the blank sample. (Good solvent resistance) B: Colored slightly lighter than the blank sample.
(Slightly good solvent resistance) C: The coating layer dissolves and is not colored. (Poor solvent resistance)

3. Anti-blocking property 5 including the coated and non-coated surfaces of the film.
After holding for 13 hours under the condition of 5 ° C. × load of 50 kg / cm ² , the peel strength of the mating surfaces was measured and evaluated as follows. A: Peel strength ≤ 7 g (good blocking resistance) B: 7 g <Peel strength ≤ 12 g (some blocking resistance) C: 12 g <Peel strength (poor blocking resistance)

[Example 1] Polyethylene terephthalate having an intrinsic viscosity of 0.64 was melted and cast on a cooling drum to obtain an unstretched film. The unstretched film was heated to 91 ° C.
The film was heated to 1, and stretched 3.5 times in the machine direction to obtain a uniaxially stretched film. Then, on one side of this uniaxially stretched film, 88 mol% of terephthalic acid as a dicarboxylic acid component and 5 adipic acid were used.
Mol% and 5-K sulfoisophthalic acid 7 mol%, ethylene glycol 91 mol% as a glycol component, 1,4
38 parts by weight of a copolyester (E-1: average molecular weight 21,770) obtained by using 7 mol% butanediol and 2 mol% glycerin, methyl methacrylate component 3
4 mol%, ethyl methacrylate component 42 mol%, ethyl acrylate component 11 mol%, acrylic acid component 1 mol%,
Glycidyl methacrylate component 5 mol%, acrylic acid 2-
41 parts by weight of a copolymer (A-1: average molecular weight 52,300) of 4 mol% of a hydroxyethyl component and 3 mol% of an N-methoxymethylacrylamide component, 6 parts by weight of a carbodiimide compound of the formula (I-2), 5% by weight of a composition comprising 5 parts by weight of the carbodiimide compound of the formula (I-3) and 10 parts by weight of an ethylene oxide / propylene oxide / block copolymer (average molecular weight: 7,330).
The aqueous coating solution was applied with a gravure coater. Then 102
After drying at ℃, stretched 3.9 times in the transverse direction at 109 ℃, and further heat-treated at 232 ℃ to give a total thickness of 76 μm and a coating thickness of 0.1.
A 1 μm laminated film was prepared. The characteristics of this laminated film are shown in Table 1.

[Examples 2 to 8] Laminated films were obtained in the same manner as in Example 1 except that the kind and blending amount of the carbodiimide compound and the thickness of the coating film were changed as shown in Table 1. The properties of these laminated films are shown in Table 1.

Comparative Example 1 A polyester film was obtained in the same manner as in Example 1 except that no coating film was applied. The characteristics of this film are shown in Table 1.

[Comparative Example 2] A laminated film was obtained in the same manner as in Example 1 except that a carbodiimide compound was not added as a coating film component. The characteristics of this laminated film are shown in Table 1.

[0047]

[Table 1]

In the types of carbodiimide compounds shown in Table 1, (I-1) to (I-6) are represented by formulas (I-1) to (I-6) of the carbodiimide compound (B). It is a compound.

As is clear from Table 1, the laminated films of Examples 1 to 8 had an easily-adhesive coating film having excellent adhesiveness, solvent resistance and blocking resistance.

[0050]

INDUSTRIAL APPLICABILITY In the present invention, since a cross-linking agent having a specific structure is used in the easily adhesive coating film component, a laminated film having excellent solvent resistance and blocking resistance can be provided. In particular, the coating liquid used for applying the easily adhesive coating in the present invention can be used as an aqueous coating liquid, and has good stability when stored as an aqueous coating liquid, so that it is safe and economical. Can be used.

The laminated film of the present invention is useful for a membrane film, an electronic material, a graphic material, a magnetic card, a magnetic tape, a magnetic disk and the like. A membrane film structure can be made by printing a resist ink containing a photopolymerization initiator, a photosensitizer, and a colorant on bisacrylic polyurethane oligomer, bisacrylic vinyl polymer, etc., and irradiating and curing the resist ink. .

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B32B 27/30 B32B 27/30 A C08K 5/16 C08K 5/16 C09D 133/06 PGC C09D 133 / 06 PGC 167/02 PKX 167/02 PKX G11B 5/704 G11B 5/704

Claims (2)

[Claims] 1. A carbodiimide compound (B) and 100 parts by weight of at least one easily adhesive resin (A) selected from the group consisting of polyester resins, acrylic resins and acrylic modified polyester resins on at least one side of a polyester film. A laminated film provided with an easily-adhesive coating film formed by applying an aqueous coating solution containing a composition containing 1 to 35 parts by weight as a main component, drying, stretching, and then heat treatment. 2. The laminated film according to claim 1, wherein the easily-adhesive coating film is formed by applying an aqueous coating solution, drying and stretching, and then heat treating at 150 to 270 ° C.