JP3024585B2 - Polyester composite film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a biaxially stretched polyester film excellent in various processability such as lubricity, adhesion and antistatic properties, specifically various coating films, films for flexible printed circuits, P
The present invention relates to a polyester film suitable for a PC film, various image receiving base films, various laminated films, labels, and the like.

[0002]

2. Description of the Related Art Conventionally, for such applications, films obtained by subjecting a polyester biaxially stretched film to surface treatment with various resins have been used.

[0003]

However, although these conventional surface-treated films have good initial characteristics, they have the disadvantage of lacking in durability such as moisture resistance, especially high-temperature moisture resistance, or have a rough surface such as a sand mat. There is a drawback that the adhesiveness after the forming process is inferior. The present invention has improved such a problem and has improved durability.

[0004]

SUMMARY OF THE INVENTION The present invention provides: 1) a polyester resin B on at least one side of a polyester resin A, and a water-soluble and / or water-dispersible resin laminated on the polyester resin _A ; Resin B
And ΔH _B > ΔH _A > ΔH _B , and the water-soluble and / or water-dispersible resin does not contain water-dispersible and / or water-soluble polyester containing inert particles as a main component. 2) The polyester composite film according to (1), wherein ΔH _B is 0 to 10 cal / g, and 3) the water-soluble or water-dispersible resin is stretched at least uniaxially. The polyester composite film according to (1), wherein the polyester composite film is formed.

The polyester resin (A, B) used in the present invention is a polymer containing an ester group obtained by condensation polymerization of a dicarboxylic acid and a diol. Examples of the dicarboxylic acid include terephthalic acid, isophthalic acid, adipic acid, sebacic acid, 2,6-naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid, bis-α, β
Examples thereof include aliphatic and aromatic dicarboxylic acids such as (2-chlorophenoxy) ethane-4,4'-dicarboxylic acid, succinic acid, and oxalic acid, and mixtures thereof.
As the diol, for example, ethylene glycol, 1,4
-Butanediol, diethylene glycol, polyethylene glycol, neopentyl glycol, cyclohexanedimethanol, polyethylene glycol and the like, and mixtures thereof. The intrinsic viscosity of such a polyester resin is preferably from 0.4 to 2.0, more preferably from 0.5 to 1.0, as measured in o-chlorophenol at 25C.

In the present invention, it is necessary that the melting energy ΔH _{A of the} polyester resin _A > the melting energy ΔH _B of the polyester resin B. In particular, ΔH _A ≧ 1
1 cal / g, more preferably ΔH _A ≧ 12 cal / g
g is preferable. ΔH _B ≦ 10 cal /
g preferably is preferably for greater effect of the present invention ΔH _B ≦ 8cal / g, more preferably from ΔH _B ≦ 4cal / g.

Representative examples of the resin A that can be used in the present invention include polyethylene terephthalate, polyethylene-2,
6-naphthalate and polyethylene-α, β-bis (2-chlorophenoxy) ethane-4,4′-dicarboxylate.

As the resin B, terephthalic acid and isophthalic acid are used as acid components in a ratio of 100 mol% to 0 mol% to 60 mol% to 40 mol%, and ethylene glycol and cyclohexane dimethanol are used as alcohol components. Mol% to 0 mol% to 60 mol% to 40 mol%
Typical examples thereof include those copolymerized in the above ratio or those obtained by changing the above isophthalic acid to sebacic acid or adipic acid. The same effect can be obtained by making the molecular weight larger than that of the resin A.

The polyester resin used in the present invention contains other kinds of polymers, ultraviolet absorbers, lubricants, pigments, antioxidants, heat stabilizers, flame retardants, antistatic agents as long as the object of the present invention is not impaired. And the like.

The lubricants and light-shielding agents contained in the resins A and B of the present invention include particles formed during polymerization by various nucleating agents,
Aggregates, spherical or jute-like silicon dioxide particles, calcium carbonate particles, alumina particles, inorganic particles such as titanium oxide particles, barium sulfate particles, and organic particles such as cross-linked polystyrene particles, acrylic particles, imide particles, Alternatively, a mixture thereof can be mentioned as a typical example.

From the viewpoint of characteristics, it is important to control the amount of the resin B particles, and the particle formulation of the resin A is not limited.

The particle size of the various particles used in the resin B is not particularly limited, but usually the average particle size measured by a sedimentation method or a light scattering method is 0.01 to 10 μm, preferably 0.1 to 4.0 μm. Can be given as a representative. Among them, it is preferable to use two or more kinds of particles having an average particle diameter ratio of 1: 2 or more, preferably 1: 3 or more. When light-shielding properties are required, barium sulfate, titanium oxide, calcium carbonate and the like are preferably added in an amount of 5 to 20% by weight.

It is desirable that both resins A and B of the film of the present invention are biaxially stretched. Further, the film thickness in the present invention is not particularly limited, but is usually 0.1 to
It is 1500 μm, preferably 0.5 to 300 μm.

The resin B may be laminated on both sides of the resin A or may be one side.

Although the thickness of the resin B is not particularly limited,
A typical thickness is 0.01 to 50 μm, preferably 0.08 to 10 μm.

The resin A does not need to be a single layer.

The function of the water-soluble or water-dispersible resin layer in the present invention varies depending on the type of the resin layer and the type and use of the polyester biaxially stretched film as a base.
Examples include easy adhesion, antistatic properties, slipperiness, and releasability.

The water-soluble or water-dispersible resin in the present invention may be any resin which does not contain a water-dispersible and / or water-soluble polyester containing inert particles and is soluble or dispersed in water. The thermoplasticity and thermosetting properties are not particularly limited, but typical examples include the following. Acrylic resin, urethane resin, polyester resin, olefin resin, fluorine resin,
Examples include vinyl resins, chlorine resins, styrene resins, various graft resins, epoxy resins, urea resins, silicone resins, polyamide resins, and the like. Further, the method of applying the composition is not particularly limited, but when the resin layer is stretched, the adhesiveness is better and more preferable.

Among them, preferred water-soluble or water-dispersible resins include the following, or mixtures thereof. However, the term “water-soluble or water-dispersible” as used herein means a slight amount, and the amount is not particularly limited, but is usually 20 or less.
It may contain a substance other than water, such as various organic solvents, in an amount of up to 10% by weight, preferably up to 10% by weight.

(A) Acrylic resin At least 40 mol% of acrylic and / or methacrylic monomer and other functional group-containing monomer 0.1 to 20
Mole% and from about 0 to 49.0 mole% of one or more halogen-free monoethylenically unsaturated monomers, or at least 25 mole% of acrylic acid, methacrylic acid or alkyl of acrylic acid or methacrylic acid Copolymers derived from comonomers selected from esters and 1 to 50 mol% of comonomers selected from vinylsulfonic acid, allylsulfonic acid, methacrylsulfonic acid and p-styrenesulfonic acid and salts of these acids. Coalescence can be mentioned.

(B) Vinyl resin General formula

[0022]

Embedded image

(Where R ₁ and R ₂ are hydrogen or an alkyl group; M ₁ and M ₂ are hydrogen, an alkali metal, an alkaline earth metal, ammonium (including substituted ammonium))
Or an alkyl group, wherein M ₁ and M ₂ are not simultaneously an alkyl group. ).

(C) Urethane Resin Resin Polyurethane whose affinity for water is enhanced by a carboxylic acid group, a sulfonic acid group or a sulfuric acid half ester base can be mentioned. However, the amount of a base such as a carboxylate group, a sulfonate group and a half-sulfate base is preferably 0.5 to 15% by weight, and the polyhydroxy compound used for the synthesis of polyurethane is, for example, polyethylene glycol, polypropylene glycol, polyethylene glycol. Propylene glycol, polytetramethylene glycol, hexamethylene glycol, tetramethylene glycol,
1,5-pentanediol, diethylene glycol, triethylene glycol, polycaprolactone, polyhexamethylene adipate, polyhexamethylene sebacate, polytetramethylene adipate, polytetramethylene sebacate, trimethylolpropane, trimethylolethane, pentaeristol, Glycerin and the like can be mentioned. Examples of the polyisocyanate compound include hexamethylene diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, isophorone diisocyanate, an adduct of tolylene diisocyanate and trimethylolpropane, and an adduct of hexamethylene diisocyanate and trimethylolethane. As the carboxylic acid-containing polyol,
For example, dimethylolpropionic acid, dimethylolbutyric acid,
Examples include dimethylol valeric acid and bis (ethylene glycol) trimellitate. Examples of the amino acid-containing carboxylic acid include β-aminopropionic acid, γ-aminobutyric acid, p-aminobenzoic acid, and the like. As the hydroxyl group-containing carboxylic acid, for example, 3
-Hydroxypropionic acid, γ-hydroxybutyric acid, p-
(2-Hydroxyethyl) benzoic acid, malic acid and the like can be mentioned. Examples of the compound having an amino group or a hydroxyl group and a sulfone group include, for example, aminomethanesulfonic acid, 2-aminoethanesulfonic acid, 2-amino-5-methylbenzene-2-sulfonic acid, sodium β-hydroxyethanesulfonic acid, and aliphatic Examples thereof include propane sultone and butane sultone addition products of di-primary amine compounds, and preferred examples include propane sultone addition products of aliphatic di-primary amine compounds. Furthermore, examples of the compound containing an amino group or a hydroxyl group and a sulfuric acid half ester group include aminoethanol sulfate, ethylenediamine ethanol sulfate, aminobutanol sulfate, hydroxyethanol sulfate, γ-hydroxypropanol sulfate, α-hydroxybutanol sulfate, and the like. .

Alternatively, JP-B-42-24194, JP-B-46-7720, and JP-B-46-101.
No. 93, JP-B-49-37839, JP-A-5
Examples thereof include a polyurethane resin having an anionic group known in JP-A No. 0-123197, JP-A-53-126058, and JP-A-54-138098 or a polyurethane resin similar thereto.

Here, the main constituent components of the polyurethane-forming component are a polyisocyanate, a polyol, a chain extender, a crosslinking agent and the like.

Further, a resin comprising a polyol having a molecular weight of 300 to 20,000, a polyisocyanate, a chain extender having a reactive hydrogen atom, a group having a group which reacts with an isocyanate group, and a compound having at least one anionic group is preferable.

The anionic group in the polyurethane resin is
Preferably _{-SO 3 H, -OSO 2 H,} -COOH and these ammonium salts, lithium salts, sodium salts, is used as the potassium salt or magnesium salt.

The amount of the anionic group in the polyurethane resin is preferably 0.05% by weight to 8% by weight.

(D) Polyester Resin A polyester copolymer comprising a dicarboxylic acid in which 0.5 to 15 mol% of all dicarboxylic acid components are a dicarboxylic acid containing a sulfonic acid metal base, and a polyhydric alcohol may be mentioned. it can.

However, the dicarboxylic acids containing a sulfonic acid metal base include sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, and 5 [4-sulfophenoxy acid. Metal salts such as isophthalic acid; and particularly preferred are 5-sodium sulfoisophthalic acid and sodium sulfoterephthalic acid.

Alternatively, an aqueous polyester resin having at least one kind of free carboxylic acid group and carboxylic acid group in the molecule, a crosslinking agent having two or more epoxy groups, and a compound containing a reaction accelerating compound if necessary. Can be. However, in order to introduce a carboxylic acid group into the molecule of the aqueous polyester resin, for example, trimellitic anhydride, trimellitic acid, pyromellitic anhydride, pyromellitic acid, trimesic acid, cyclobutanetetracarboxylic acid,
It is preferable to use a polyvalent compound such as dimethylolpropionic acid as one of the raw materials for producing the polymer. The carboxylate can be introduced by neutralizing the carboxylic acid group introduced into the polymer with an amino compound, ammonia, an alkali metal or the like.

(E) Various graft resins Comb-type graft polymers having polymethyl methacrylate as a main chain and poly 2-hydroxyethyl methacrylate as a branch chain can be exemplified.

Alternatively, there may be mentioned an acrylic graft polyester in which the backbone polymer is a polyester and the branch polymer is an acrylic polymer.

However, the polyester serving as the backbone polymer of the aqueous polyester-acryl graft polymer is a substantially linear polymer synthesized from a polybasic acid or its ester-forming derivative and a polyol or its ester-forming derivative. . As the polybasic acid component of this polymer,
Illustrate terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, trimellitic acid, pyromellitic acid, dimeric acid, etc. Can be. Two or more of these components can be used. Furthermore, maleic acid, fumaric acid,
An unsaturated polybasic acid such as itaconic acid or a hydroxycarboxylic acid such as p-hydroxybenzoic acid or p- (β-hydroxyethoxy) benzoic acid can be used in a small proportion. The proportion of the unsaturated polybasic acid component or hydroxycarboxylic acid component is at most 10 mol%, preferably 5 mol% or less.

The polyol component includes ethylene glycol, 1,4-butanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, xylylene glycol, dimethylol. Propionic acid, glycerin, trimethylolpropane,
Examples thereof include poly (ethylene oxide) glycol and poly (tetramethylene oxide) glycol. Two or more of these can be used.

Examples of the monomer of the acrylic polymer include alkyl acrylate and alkyl methacrylate (the alkyl group is a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group,
-Butyl group, 2-ethylhexyl group, cyclohexyl group, phenyl group, benzyl group, phenylethyl group, etc.),
Hydroxy-containing monomers (such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, and 2-hydroxypropyl methacrylate), and amide group-containing monomers (acrylamide, methacrylamide, N-methylmethacrylamide, and N-methylacrylamide) , N-methylolacrylamide, N-methylolmethacrylamide, N, N-
Dimethylolacrylamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide, N
-Phenylacrylamide, etc.), amino group-containing monomers (N, N-diethylaminoethyl acrylate, N, N
A monomer containing an epoxy group (glycidyl acrylate, glycidyl methacrylate, etc.), a monomer containing a carboxyl group or a salt thereof (acrylic acid, methacrylic acid and salts thereof (sodium salt, potassium salt, ammonium salt)) etc)
And the like. These can be used in combination with other monomers. Other types of monomers include, for example, monomers containing an epoxy group (such as allyl glycidyl ether) and monomers containing a sulfonic acid group or a salt thereof (styrene sulfonic acid, vinyl sulfonic acid and salts thereof (sodium salt, potassium salt, ammonium salt, etc.) Etc.), a monomer containing a carboxyl group or a salt thereof (crotonic acid, itaconic acid, maleic acid, fumaric acid and salts thereof (sodium salt, potassium salt, ammonium salt, etc.), etc.), and a monomer containing an acid anhydride ( Maleic anhydride, itaconic anhydride, etc.), vinyl isocyanate, allyl isocyanate, styrene,
Examples include vinyl methyl ether, vinyl ethyl ether, vinyl trisalkoxysilane, alkyl maleate monoester, alkyl fumarate monoester, acrylonitrile, methacrylonitrile, alkyl itaconate monoester, vinylidene chloride, vinyl acetate, and vinyl chloride. The above-mentioned monomers are copolymerized using one kind or two or more kinds.

(F) Block polymer An aqueous acrylic polymer-polyester block polymer can be exemplified. However, monomers of the acrylic polymer constituting the block polymer include, for example, alkyl acrylate, alkyl methacrylate (the alkyl group is a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group, phenyl group, benzyl group, phenylethyl group, etc., hydroxy-containing monomer (2-hydroxyethyl acrylate,
Hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, etc., amide group-containing monomers (acrylamide, methacrylamide, N-methylmethacrylamide, N-methylacrylamide, N-methylolacrylamide, N
-Methylol methacrylamide, N, N-dimethylolacrylamide, N-methoxymethylacrylamide,
N-methoxymethyl methacrylamide, N-phenylacrylamide, etc.), amino group-containing monomers (N, N-diethylaminoethyl acrylate, N, N-diethylaminoethyl methacrylate, etc.), epoxy group-containing monomers (glycidyl acrylate, glycidyl methacrylate, etc.), Monomers containing a carboxyl group or a salt thereof (acrylic acid, methacrylic acid and salts thereof (sodium salt, potassium salt, ammonium salt, etc.) and the like) and the like. These can be used in combination with other monomers. Other monomers include monomers containing an epoxy group (such as allyl glycidyl ether) and monomers containing a sulfonic acid group or a salt thereof (styrene sulfonic acid, vinyl sulfonic acid and salts thereof (sodium salt, potassium salt, ammonium salt, etc.)) ), A monomer containing a carboxyl group or a salt thereof (crotonic acid, itaconic acid, maleic acid, fumaric acid and salts thereof (sodium salt, potassium salt, ammonium salt, etc.), etc.), and a monomer containing an acid anhydride (anhydrous Maleic acid, itaconic anhydride, etc.), vinyl isocyanate,
Examples include allyl isocyanate, styrene, vinyltrisalkoxysilane, alkylmaleic acid monoester, alkylfumaric acid monoester, acrylonitrile, methacrylonitrile, alkylitaconic acid monoester, vinylidene chloride, vinyl acetate, and vinyl chloride.
The above-mentioned monomers can be copolymerized using one kind or two or more kinds. From the viewpoints of imparting hydrophilicity to an acrylic polymer, dispersion stability of an aqueous solution, and adhesion to a polyester film, hydroxyl groups, Those having a functional group such as an amide group, a carboxyl group or a salt thereof (sodium salt, potassium salt, ammonium salt, etc.) are preferable.

The polyester, another component of the aqueous block polymer, is a substantially linear saturated polyester synthesized from a polybasic acid or its ester-forming derivative and a polyol or its ester-forming derivative. Polybasic acid components of this polyester include terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride,
Examples thereof include 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, trimellitic acid, pyromellitic acid, and dimer acid. Two or more of these can be used. In addition, p-hydroxybenzoic acid, p-
Hydroxycarboxylic acids such as (β-hydroxyethoxy) benzoic acid can also be used.

The polyol component includes ethylene glycol, 1,4-butanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, xylylene glycol, dimethylol. Propionic acid, glycerin, trimethylolpropane,
Examples thereof include poly (ethylene oxide) glycol and poly (tetramethylene oxide) glycol. Two or more of these can be used.

The polyester is preferably an aqueous polymer, for example, an organic sulfonate, a carboxylate,
Those containing a compound having a hydrophilic group, such as diethylene glycol and polyalkylene ether glycol, are advantageous for preparing an aqueous dispersion and are preferred. This carboxylic acid salt is usually introduced using a carboxylic acid having three or more functional groups. However, since the carboxylic acid is likely to be gelled due to branching in the polymerization step, it is desirable to reduce the copolymerization ratio. In that respect, introduction of a hydrophilic group with sulfonic acid, diethylene glycol, polyalkylene ether glycol, or the like does not have these problems and is more advantageous.

In order to introduce a sulfonate group into the polyester molecule, for example, 5-Na sulfoisophthalic acid, 5-ammonium sulfoisophthalic acid, 4-Na sulfoisophthalic acid, 4-methylammonium sulfoisophthalic acid, -Na sulfoterephthalic acid, 5-K sulfoisophthalic acid, 4-K sulfoisophthalic acid, 2-K sulfoterephthalic acid, Na sulfosuccinic acid, and other alkali metal salt-based or sulfonated amine-based compounds may be used. preferable. The polyhydric carboxylic acid or polyhydric alcohol having a sulfonic acid salt group preferably accounts for 0.5 to 20 mol%, more preferably 1 to 18 mol%, of the total polyhydric carboxylic acid component or polyhydric alcohol component.

In the water-soluble or water-dispersible resin layer of the present invention, various crosslinking agents may be used as necessary. The type is not particularly limited, but typical examples include isocyanate-based crosslinking agents, isocyanurate-based crosslinking agents, melamine-based crosslinking agents, urea-based crosslinking agents, oxazoline-based crosslinking agents or epoxy-based crosslinking agents, and oxazoline-based crosslinking agents. Can be mentioned.

Specific examples of the epoxy crosslinking agent include polyepoxy compounds, diepoxy compounds and monoepoxy compounds. Examples of the polyepoxy compounds include sorbitol, polyglycidyl ether, polyglycerol polyglycidyl ether, and pentaerythritol Examples of polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanate, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, and diepoxy compounds include neopentyl glycol diglycidyl ether, 1,6- Hexanediol diglycidyl ether, resorcin diglycidyl ether, ethylene glycol diglycidyl ether,
Examples of polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, and monoepoxy compounds include, for example, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, and the like. . Examples of the isocyanate-based crosslinking agent include, for example, tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and the like. Examples thereof include dimethylol urea, dimethylol ethylene urea, dimethylol propylene urea, tetramethylol acetylene urea, 4 ethoxy 5 dimethyl propylene urea dimethylol, and the like. As the melamine-based cross-linking agent, a compound obtained by reacting a methylol melamine derivative obtained by condensing melamine and formaldehyde with methyl alcohol, ethyl alcohol, isopropyl alcohol or the like as a lower alcohol, and a mixture thereof are preferable. Examples of the methylol melamine derivative include monomethylol melamine, dimethylol melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, hexamethylol melamine and the like.
These crosslinking agents may be used alone or in combination of two or more in some cases.

In the present invention, the thickness of the water-soluble or water-dispersible resin layer is not particularly limited, but a preferable range is 0.001 μm to 0.5 μm, preferably 0.01 μm to 0.5 μm.
1 μm to 0.3 μm, more preferably 0.06 μm
0.15 μm.

This is because when the thickness is less than 0.001 μm, the effect of improving the adhesiveness is slightly reduced.
When it is thicker, the moisture resistance and the solvent resistance slightly deteriorate.

The thickness of the resin layer can be measured by various methods. For example, the cross section of the laminated film can be measured with an electron microscope, or when the resin layer can be removed with a solvent or the like, the removed portion and the removed portion are removed. It can also be obtained from the step of the part that does not exist.

Various lubricating and anti-blocking particles can be added to the present water-soluble or water-dispersible resin layer except when the main component is a water-dispersible and / or water-soluble polyester resin. Examples of particles to be added include inorganic particles such as silicon oxide, alumina oxide, calcium oxide, talc, clay, and lithium fluoride in various shapes such as agglomerated or true sphere, or crosslinked-non-crosslinked silicon, acrylic, and amide. Organic, polyester, fluorine, and olefin organic particles. In particular, when organic particles are used as the lubricating main component, the particles are less likely to fall off because of good affinity with a water-soluble or water-dispersible resin.

The particle size added here is not particularly limited, but is usually 0.05 to 20 μm, preferably 0.1 to 20 μm.
It is about 10 μm. However, the particle size is measured by a sedimentation method or a light scattering method.

In the present invention, the water-soluble or water-dispersible resin layer is preferably stretched. This is because the affinity with the base polyester resin B is further improved by stretching. As a typical example of a method for determining the presence or absence of stretching by a product, the determination based on the presence or absence of the orientation of the water-soluble or water-dispersible resin using FT-IR or the like can be given.

As a method of giving a stretch to the resin layer, a method of stretching a film coated with the resin together with a base film can be mentioned.

Next, a typical method for producing the polyester composite film of the present invention will be described. However, the present invention is not limited to the following method.

First, the pellets of the polyester resins A and B, to which polymerization and various additives have been added as required, are sufficiently dried by a conventional method, and then each of the pellets is 250 to 35 using a known extruder.
After melt-kneading in the range of 0 ° C., A,
B is melt-extruded into a laminated sheet, cooled and solidified on a drum to form an unstretched sheet. The unstretched film or unstretched film thus obtained is uniaxially stretched, if necessary, on a film obtained by subjecting it to a surface treatment such as a corona discharge treatment. After that, a water-soluble or water-dispersible resin is applied using a known method (gravure coat, reverse coat, kiss coat, die coat, bar coat, comma coat, etc.). The thus obtained composite film is stretched. The stretching direction is not particularly limited, but when applied on a film stretched in a uniaxial direction, the film is usually stretched in a direction perpendicular to the uniaxial direction. When applied on an unstretched film, the film may be stretched in either the vertical or horizontal direction, or may be simultaneously stretched in the biaxial direction. The unstretched film is stretched at a stretching temperature of 7
The film is stretched 2.0 to 10.0 times in the machine direction at 0 to 120 ° C, and after cooling, is stretched 2.0 to 6.0 times in the transverse direction at 70 to 160 ° C. Thereafter, heat treatment is performed at 150 to 250 ° C. for a predetermined period of time, optionally in the range of 0 to 30% while relaxing in the lateral direction. After passing through the cooling step as necessary, a heat treatment may be performed while performing a relaxation treatment in the range of 0 to 30% in the vertical direction.

After the biaxially stretched film is appropriately subjected to surface treatment such as corona discharge treatment as necessary,
It goes without saying that a predetermined water-soluble or water-dispersible resin may be applied and dried.

The measuring method and the method for evaluating the effects of the present invention are as follows.

(1) Melting energy (ΔH _A , ΔH _B ) 1) Measuring machine: Differential operation calorimeter 2) Melting energy: Heating at 10 ° C./min, area S ₁ under endothermic curve observed by melting (The baseline is
The connection is made between the melting start temperature and the end temperature. ) Is compared with the area S ₂ under the endothermic curve of In (indium) measured under the same conditions, and S ₁ / S ₂ × 6.8 = ΔH (cal /
g).

The resin A is represented by ΔH _A , and the resin B is represented by ΔH _B.

When it is difficult to separate the resin A and the resin B, the degree of crystallinity of each of the resins A and B is conveniently compared (the degree of crystallinity can be evaluated by, for example, FT-IR laser Raman, etc. (Analysis of the resin composition is performed by IR and NMR according to the above.) It may be used as an index for determining the magnitude of ΔH _A and ΔH _B.

(2) Adhesion: UV manufactured by Acheson Co., Ltd.
450SS of effect type resist ink and ML25089 1
The ink mixed and prepared in one-to-one manner was applied to the water-soluble or water-dispersible resin layer surface of the sample film with a 225 mesh screen, and 2.5 under a high-pressure mercury lamp of 80 W / cm.
Pass at m / min to effect. This printing operation is repeated three times to form a resist ink layer having a thickness of 45 μm on the sample film. The film sample and the film
Each of the samples left at 0 ° C. and 95% RH for 500 hours was subjected to 180 ° peeling at a peeling speed of 200 mm / min, and the force (g / cm) required for peeling was indicated as an adhesive force.

[0060]

EXAMPLES As the resin A, a homopolymer of polyethylene terephthalate (intrinsic viscosity = 0.
62, melting point 259 ° C., ΔH _A = 13 cal / g), the same component as resin A (Comparative Examples 1 and 2) as resin B, or terephthalic acid as an acid component and ethylene glycol as an alcohol component with isophthalic acid. The ratio of terephthalic acid to isophthalic acid is 97.5 to 2.5.
(Example 1), 95: 5 (Example 2), 90:10 (Examples 3, 7), 85:15 (Example 4), 80:20
(Example 5) A polymer having a molar ratio of not less than that was prepared.

A polymer (Example 6) consisting of terephthalic acid as an acid component and ethylene glycol and cyclohexanedimethanol 60/40 as an alcohol component was prepared. Resin B has an average particle size of 1.0 μm as evaluated by the sedimentation method.
m was added in an amount of 0.05% by weight.

The resins A and B were dried at 180 ° C. for 3 hours, and in the case of Examples 3 to 6 at 110 ° C. for 18 hours, and then melted using an extruder to obtain resin B, resin A and resin B. Laminate in order, extrude from die, surface temperature 20 using electrostatic application method
C. and wound around a cooling drum to be cooled and solidified to obtain an unstretched film.

The unstretched film was stretched 3.3 times in the longitudinal direction at 90 ° C., and a corona discharge treatment was applied to one surface of the uniaxially stretched film, and then a resin (I) (shown below) was applied and dried. . Then, after extending | stretching 3.6 times in the horizontal direction at 110 degreeC, it heat-processed at 220 degreeC, relaxing 3.5% in the horizontal direction. (Comparative Example 1, Examples 1-4) The thickness after stretching is 100 μm for resin A, 0.3 μm for resin B, and resin (I).
It was 0.1 μm.

Further, after one surface of the unstretched film was subjected to a corona discharge treatment, the resin (I) was applied and dried, and then simultaneously biaxially stretched 3.4 times each in the vertical and horizontal directions. The film was also heat-treated at 220 ° C. while relaxing 3.5% in the transverse direction. (Examples 5 and 6) The thickness of each layer is the same as in Example 1.
Was the same as

Further, after applying a corona discharge treatment to one surface of the film subjected to biaxial stretching and heat treatment in the same manner as in Comparative Example 1 and Example 3 without applying the resin (I), the resin (I)
I) was applied and dried (Comparative Example 2, Example 7). The thickness of each layer was the same as in Example 1.

Each film was evaluated for ΔH _A , ΔH _B and adhesion, and the results are shown in Table 1.

Resin (I): A polymer consisting of 50 mol% of methyl methacrylate and 50 mol% of butyral acrylate, but 2.5 mol% of each of —CH ₂ OH and —COOH groups are introduced for hydrophilicity. In addition, silicon oxide having an average particle diameter of 0.8 μm by a precipitation method is 0.8% by weight in terms of solid content.
Including.

Resin (II): A polymer of 50 mol% to 50 mol% of ethyl acrylate and butyral acrylate, but 2.5 mol% of each of —CH ₂ OH and —COOH groups are introduced for hydrophilicity. In addition, silicon oxide having an average particle diameter of 0.8 μm by a precipitation method is 0.8% by weight in terms of solid content.
Including.

[0069]

[Table 1]

[0070]

EFFECT OF THE INVENTION A water-soluble resin containing a polyester film containing inert particles and / or a water-soluble resin containing no water-soluble polyester as a main component, or a water-dispersible resin to improve lubricity, adhesion and antistatic properties. In the surface treatment for the purpose of (1), the interfacial adhesion between the polyester film and the water-soluble or water-dispersible resin layer, especially the high humidity durability, was improved.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification code FIB29L 9:00 (56) References JP-A-4-105937 (JP, A) JP-A-51-50988 (JP, A) Kaihei 2-214648 (JP, A) Jikaga Sho 49-108874 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 27/36

Claims (3)

(57) [Claims] 1. A polyester resin B and a water-soluble and / or water-dispersible resin are laminated on at least one surface of the polyester resin A, and the melting energy ΔH _A of the resin _A and the melting energy ΔH _{B of the} resin _B are ΔH _A. > ΔH _B , and wherein the water-soluble and / or water-dispersible resin does not contain a water-dispersible and / or water-soluble polyester containing inert particles as a main component. 2. The polyester composite film according to claim 1, wherein ΔH _B is 0 to 10 cal / g. 3. The water-soluble or water-dispersible resin is stretched at least uniaxially.
The polyester composite film of the above.