JP2000006330A - Easily bondable syndiotactic polystyrene-based biaxially oriented film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the transparency and adhesion of a film by a method wherein as a specified self-crosslinkable polyester-based graft copolymer, which includes one kind of a monomer containing an anhydride having a double bond, is formed on one side of a syndiotactic polystyrene-based biaxially oriented film. SOLUTION: On one side of a syndiotactic polystyrene-based biaxially oriented film, in which either one of lubricants such as inert particles or the like is singly used for a syndiotactic polystyrene-based polymer consisting of particles made of a metal oxide such as silica, titanium dioxide, talc, kaolinite or the like; a metal salt such as calcium carbonate, calcium phosphate, barium sulfate or the like of an organic polymer; a self-crosslinkable polyester-based graft copolymer, in which one kind or more of polymerizable unsaturated monomers is grafted to a hydrophobic polyester-based resin. The graft copolymer contains one kind of monomer including an anhydride having a double bond.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biaxially stretched syndiotactic polystyrene-based film, and more particularly, to a biaxially stretched syndiotactic polystyrene-based film having excellent transparency and adhesiveness.

[0002]

2. Description of the Related Art Syndiotactic polystyrene biaxially stretched films have excellent heat resistance, electrical properties, transparency, etc.
It is expected to be used in various film applications such as magnetic tapes, photographic / plate making, capacitors, and packaging. In particular, when the film is used as a packaging material, generally, at least one surface of the biaxially stretched film is subjected to printing or an organic barrier layer, an inorganic or metal vapor-deposited layer as necessary, and further provided with an adhesive. A sealant layer is provided by a dry lamination method, or a sealant layer is provided by an extrusion lamination method to form a laminate of films, a bag is formed using the laminate, the contents are filled, and the opening is heat-sealed. For example, seasonings such as miso and soy sauce, water-containing foods such as soups and retort foods, and chemicals are packaged and provided to general consumers. Also,
Heretofore, it has been general to provide an adhesion-modified layer in consideration of the adhesiveness with a printing layer, an organic barrier layer, a sealant layer, or the like when forming the above-mentioned laminate.

[0003]

However, in the case of the above-mentioned polystyrene-based film, it is difficult to provide an adhesion-modified layer because of its properties. For example, when a conventional water-based coating agent is used, the surface energy of the film is low, so that repelling of the coating liquid occurs and the appearance is impaired. Further, when a solvent-based coating agent is used, it is not preferable in consideration of hygiene and recyclability. Therefore, the present invention provides an aqueous coating agent that can be applied to the above-mentioned polystyrene film, and a laminated syndiotactic polystyrene-based biaxially stretched film excellent in adhesion to a sealant layer by applying the aqueous coating agent. The purpose is to:

[0004]

Means for Solving the Problems A self-crosslinking polymer comprising a hydrophobic polyester resin and one or more polymerizable unsaturated monomers grafted on at least one surface of the syndiotactic polystyrene-based biaxially stretched film of the present invention. A syndiotactic laminated adhesive modification layer, which is a polyester-based graft copolymer, wherein the graft copolymer contains at least one monomer containing an acid anhydride having a double bond. The above object can be achieved by forming a polystyrene film. In a further preferred embodiment of the present invention, the polymerizable unsaturated monomer contains at least a combination of maleic anhydride and styrene.

The polystyrene polymer having a syndiotactic stereoregularity used in the present invention includes:
Polystyrene, poly (p-, m- or o-methylstyrene),
Poly (2,4-, 2,5-, 3,4- or 3,5-dimethylstyrene),
Poly (alkylstyrene) such as poly (p-tert-butylstyrene), poly (p-, m- or o-chlorostyrene), poly (p-, m- or o-bromostyrene), poly (p
-, M- or o-fluorostyrene), poly (o-methyl-p-
Poly (halogenated styrene) such as fluorostyrene), poly (halogen-substituted alkylstyrene) such as poly (p-, m- or o-chloromethylstyrene), poly (p-,
poly (alkoxystyrene) such as m- or o-methoxystyrene), poly (p-, m- or o-ethoxystyrene), poly (carboxyalkyl) such as poly (p-, m- or o-carboxymethylstyrene) (Styrene) Poly (alkyl ether styrene) such as poly (p-vinylbenzylpropyl), poly (alkylsilylstyrene) such as poly (p-trimethylsilylstyrene), and poly (vinylbenzyldimethoxyphosphide).

In the present invention, among the polystyrene polymers, polystyrene is particularly preferred. Also,
The polystyrene-based polymer having a syndiotactic structure used in the present invention is not necessarily a single compound, and a polystyrene-based polymer having an atactic or isotactic structure as long as the syndiotacticity is within the above range. Or copolymers and mixtures thereof. The polystyrene-based polymer used in the present invention has a weight average molecular weight of 10,000 or more, more preferably 50,000 or more. If the weight average molecular weight is less than 10,000, a biaxially stretched film having excellent elongation characteristics and heat resistance cannot be obtained. The upper limit of the weight average molecular weight is not particularly limited. However, if the weight average molecular weight is 1500,000 or more, breakage occurs due to an increase in stretching tension and the like, which is not preferable.

Further, the syndiotactic polystyrene-based biaxially stretched film of the present invention can be prepared by a known method, for example, a sequential biaxial stretching method in which longitudinal stretching and transverse stretching are performed in order.
We can adopt stretching methods such as horizontal / vertical / longitudinal stretching method, vertical / horizontal / longitudinal stretching method, vertical / longitudinal / horizontal stretching method, and select according to various properties such as required strength and dimensional stability Is done. In addition, it is necessary to perform a heat setting process, a vertical relaxation process, a horizontal relaxation process, and the like. Particles inactive against syndiotactic polystyrene-based polymers, such as particles composed of metal oxides such as silica, titanium dioxide, talc, kaolinite, salts of metals such as calcium carbonate, calcium phosphate, barium sulfate, and organic polymers. May be used alone or in combination of two or more.

(Graft Polymer) The graft polymerization of the present invention generally comprises reacting a radical initiator and a radical polymerizable monomer mixture in a state where a hydrophobic copolymerized polyester resin is dissolved in an organic solvent. It is implemented by. The reaction product after the completion of the grafting reaction is, in addition to the graft polymer between the desired hydrophobic copolymerized polyester-radical polymerizable monomer mixture, the hydrophobic copolymerized polyester that has not been grafted and the hydrophobic copolymerized polyester. It also contains a radical polymer not grafted to the polymerized polyester, but the graft polymer in the present invention includes all of them.

In the present invention, the acid value of a reaction product obtained by graft-polymerizing a radical polymerizable monomer onto a hydrophobic copolymerized polyester resin is preferably 600 eq / 10 ⁶ g or more. More preferably, the acid number of the reactants is 1200 eq
/ 10 ⁶ g or more. The reaction product has an acid value of 600 eq / 1
Is less than 0 ⁶ g, the adhesion between the layer to be coated in a is primed material object of the present invention is not sufficient.

Further, the weight ratio of the desired hydrophobic copolymerized polyester resin and the radical polymerizable monomer suitable for the purpose of the present invention is as follows: polyester / radical polymerizable monomer = 4
The range is preferably 0/60 to 95/5, more preferably 55/45 to 93/7, most preferably 60/40 to 9/9.
It is in the range of 0/10. When the weight ratio of the hydrophobic copolymerized polyester resin is less than 40% by weight, excellent adhesiveness of the polyester resin cannot be exhibited. on the other hand,
95% by weight of hydrophobic copolymerized polyester resin
When it is larger, blocking, which is a drawback of the polyester resin, tends to occur.

The graft polymerization product of the present invention is in the form of a solution or dispersion of an organic solvent or a solution or dispersion of an aqueous solvent. In particular, a dispersion of an aqueous solvent, that is,
The form of the water-dispersed resin is preferred in view of working environment and applicability. In order to obtain such a water-dispersed resin, usually, in an organic solvent, the hydrophobic copolymerized polyester resin is graft-polymerized with a radical polymerizable monomer containing a hydrophilic radical polymerizable monomer, This is achieved by adding water and distilling off the organic solvent. The water-dispersed resin of the present invention has an average particle size of 500 nm or less as measured by a laser light scattering method, and exhibits a translucent or milky white appearance. By adjusting the polymerization method, water-dispersed resins having various particle diameters can be obtained. The particle diameter is suitably from 10 to 500 nm, and from the viewpoint of dispersion stability, is preferably 400 nm or less, more preferably 300 nm or less.
nm or less. If it exceeds 500 nm, the gloss of the surface of the coating film is reduced, and the transparency of the coating is reduced.
Below, the water resistance, which is the object of the present invention, is reduced,
Not preferred.

The hydrophilic radically polymerizable monomer used in the polymerization of the water-dispersed resin in the present invention refers to a group having a hydrophilic group or a group which can be converted into a hydrophilic group later. As a radical polymerizable monomer having a hydrophilic group, a carboxyl group, a hydroxyl group, a phosphoric acid group, a phosphorous acid group, a sulfonic acid group, an amide group,
A radical polymerizable monomer containing a quaternary ammonium base or the like can be given. On the other hand, as radical polymerizable monomers that can be converted to hydrophilic groups, acid anhydride groups, glycidyl groups,
Chlorine and the like can be mentioned. Among these, a carboxyl group is preferable from the viewpoint of water dispersibility, and a radical polymerizable monomer having a carboxyl group or a group generating a carboxyl group is preferable. From the viewpoint of increasing the acid value of the present invention, it is preferable that the compound contains a carboxyl group or contains a radical polymerizable monomer that generates a carboxyl group.

(Polyester) In the present invention, the hydrophobic copolymerized polyester resin must be essentially water-insoluble and does not originally disperse or dissolve in water.
When a polyester resin that disperses or dissolves in water is used for graft polymerization, the adhesiveness and water resistance, which are the objects of the present invention, deteriorate.

The composition of the dicarboxylic acid component of this hydrophobic copolymerized polyester resin is as follows.
It is preferably 9.5 mol%, 0 to 40 mol% of aliphatic dicarboxylic acid and / or alicyclic dicarboxylic acid, and 0.5 to 10 mol% of dicarboxylic acid containing a polymerizable unsaturated double bond. When the amount of the aromatic dicarboxylic acid is less than 60% by mole or when the amount of the aliphatic dicarboxylic acid and / or the alicyclic dicarboxylic acid exceeds 40% by mole, the adhesive strength decreases.

When the amount of the dicarboxylic acid having a polymerizable unsaturated double bond is less than 0.5 mol%, it is difficult to efficiently graft the radical polymerizable monomer to the polyester resin. If it exceeds 10 mol%,
It is not preferable because the viscosity increases too late in the late stage of the grafting reaction, which hinders the uniform progress of the reaction. More preferably, the aromatic dicarboxylic acid is 70-98 mol%, the aliphatic dicarboxylic acid and / or the alicyclic dicarboxylic acid is 0-30 mol%.
Mol%, 2 to 7 mol% of a dicarboxylic acid containing a polymerizable unsaturated double bond.

Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, biphenyldicarboxylic acid and the like. It is preferable not to use a hydrophilic group-containing dicarboxylic acid such as 5-sodium sulfoisophthalic acid from the viewpoint of reducing the water resistance, which is the object of the present invention. Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecandionic acid, and dimer acid.Examples of the alicyclic dicarboxylic acid include 1,4-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid. Examples thereof include 3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, and acid anhydrides thereof.

Examples of dicarboxylic acids containing a polymerizable unsaturated double bond include α, β-unsaturated dicarboxylic acids such as fumaric acid, maleic acid, maleic anhydride, itaconic acid, citraconic acid, and unsaturated double acids. Examples of the alicyclic dicarboxylic acid having a bond include 2,5-norbornene dicarboxylic anhydride, tetrahydrophthalic anhydride and the like. Of these, fumaric acid, maleic acid, and 2,5-norbornene dicarboxylic acid are preferred from the viewpoint of polymerizability.

On the other hand, the glycol component has 2 to 10 carbon atoms.
And / or an alicyclic glycol having 6 to 12 carbon atoms and / or an ether bond-containing glycol. Examples of the aliphatic glycol having 2 to 10 carbon atoms include ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,
5-pentanediol, 1,9-nonanediol, 2-
Ethyl-2-butylpropanediol and the like can be mentioned, and as the alicyclic glycol having 6 to 12 carbon atoms,
1,4-cyclohexanedimethanol and the like can be mentioned.

Examples of the ether bond-containing glycol include diethylene glycol, triethylene glycol, dipropylene glycol, and glycols obtained by adding ethylene oxide or propylene oxide to two phenolic hydroxyl groups of bisphenols, such as 2,2-glycol. Bis (4-hydroxyethoxyphenyl) propane and the like can be mentioned. Polyethylene glycol, polypropylene glycol and polytetramethylene glycol can also be used if necessary.

In the copolymerized polyester resin used in the present invention, 0 to 5 mol% of a trifunctional or higher polycarboxylic acid and / or polyol can be copolymerized.
Examples of trifunctional or higher polycarboxylic acids include (anhydride) trimellitic acid, (anhydrous) pyromellitic acid, (anhydrous) benzophenonetetracarboxylic acid, trimesic acid, ethylene glycol bis (anhydrotrimellitate), glycerol tris (anhydride) Hydrotrimellitate) and the like are used. On the other hand, as trifunctional or higher polyols, glycerin, trimethylolethane, trimethylolpropane,
Pentaerythritol and the like are used. The trifunctional or higher polycarboxylic acid and / or polyol is copolymerized in the range of 0 to 5 mol%, preferably 0 to 3 mol%, based on the total acid component or total glycol component. Gelation at the time of polymerization tends to occur, which is not preferable.

Further, the molecular weight of the hydrophobic copolymerized polyester resin is preferably in the range of 5,000 to 50,000 on a weight average. When the molecular weight is less than 5000, the adhesive strength is reduced, and conversely 50
If it exceeds 000, problems such as gelation during polymerization will occur.

(Polymer containing polymerizable unsaturated monomer) The polymerizable unsaturated monomer of the present invention is, for example, a monomer of fumaric acid such as fumaric acid, monoethyl fumarate, diethyl fumarate and dibutyl fumarate. Ester or diester maleic acid and its anhydride, monoester or diester of maleic acid such as monoethyl maleate, diethyl maleate, dibutyl maleate, itaconic acid and its anhydride, monoester or diester of itaconic acid,
Maleimides such as phenylmaleimide, styrene,
Styrene derivatives such as α-methylstyrene, t-butylstyrene, and chloromethylstyrene; vinyltoluene; divinylbenzene; The acrylic polymerizable monomer includes, for example, alkyl acrylate, alkyl methacrylate (the alkyl group is a methyl group, an ethyl group,
Propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, cyclohexyl, phenyl, benzyl, phenylethyl, etc.): 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate , 2-hydroxypropyl acrylate, hydroxy-containing acrylic monomers of 2-hydroxypropyl methacrylate: acrylamide, methacrylamide, N-methylmethacrylamide, N-methylacrylamide, N-methylolacrylamide, N
-Methylol methacrylamide, N, N-dimethylolacrylamide, N-methoxymethylacrylamide,
Amide group-containing acrylic monomers of N-methoxymethyl methacrylamide and N-phenylacrylamide: N, N-
Amino group-containing acrylic monomers of diethylaminoethyl acrylate, N, N-diethylaminoethyl methacrylate: glycidyl acrylate, epoxy group-containing acrylic monomers of glycidyl methacrylate: acrylic acid, methacrylic acid and salts thereof (sodium salt, potassium salt, Acrylic monomer containing a carboxyl group such as ammonium salt) or a salt thereof. Preferably,
Maleic anhydride and its esters. The above monomers can be copolymerized by using one kind or two or more kinds.

The graft polymerization of the present invention is generally carried out by reacting a radical initiator and a radical polymerizable monomer mixture in a state where a hydrophobic copolymerized polyester resin is dissolved in an organic solvent. The reaction product after the completion of the grafting reaction is, in addition to the graft polymer between the desired hydrophobic copolymerized polyester-radical polymerizable monomer mixture, the hydrophobic copolymerized polyester that has not been grafted and the hydrophobic copolymerized polyester. It also contains a radical polymer not grafted to the polymerized polyester, but the graft polymer in the present invention includes all of them.

(Polymerization Initiator and Other Additives) As the graft polymerization initiator that can be used in the present invention, organic peroxides and organic azo compounds known to those skilled in the art can be used. As an organic peroxide, benzoyl peroxide, t-butyl peroxypivalate, as an organic azo compound,
Examples thereof include 2,2′-azobisisobutyronitrile and 2,2′-azobis (2,4-dimethylpareronitrile). The amount of the polymerization initiator used for performing the graft polymerization is at least 0.1 with respect to the polymerizable monomer.
It is at least 2% by weight, preferably at least 0.5% by weight. In addition to the polymerization initiator, a chain transfer agent for adjusting the chain length of the branch polymer, for example, octyl mercaptan, mercaptoethanol, 3-t-butyl-4-hydroxyanisole, or the like can be used as necessary. In this case, it is desirable to add in the range of 0 to 5% by weight based on the polymerizable monomer.

(Reaction Solvent) The grafting reaction solvent for carrying out the present invention is preferably composed of an aqueous organic solvent having a boiling point of 50 to 250 ° C. Here, the aqueous organic solvent has a solubility in water at 20 ° C. of at least 10 g /
L or more, desirably 20 g / L or more.
Those having a boiling point exceeding 250 ° C. are unsuitable because the evaporation rate is too slow to remove sufficiently even by baking the coating film at a high temperature. When the boiling point is 50 ° C. or less,
When the grafting reaction is carried out using it as a solvent, 50
The use of an initiator that decomposes into radicals at a temperature of not more than ° C. increases the danger in handling, which is not preferred. Examples of the first group of aqueous organic solvents that dissolve the copolymerized polyester resin well and relatively well dissolve the polymerizable monomer mixture containing the carboxyl group-containing polymerizable monomer and the polymer include esters such as ethyl acetate. Ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclic ethers such as tetrahydrofuran, dioxane, 1,3-dioxolane, glycol ethers such as ethylene glycol dimethyl ether, propylene glycol methyl ether, propylene glycol propyl ether -Ter, ethylene glycol ethyl ether, ethylene glycol butyl ether, carbitols such as methyl carbitol, ethyl carbitol, butyl carbitol, glycols or lower esters of glycol ether Such as ethylene glycol diacete
And ethylene glycol ethyl ether acetate, ketone alcohols such as diacetone alcohol, and N-substituted amides such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like.

On the other hand, as a second group of aqueous organic solvents, which hardly dissolve the copolymerized polyester resin but contain the carboxyl group-containing polymerizable monomer and dissolve the polymer relatively well, , Water, lower alcohols, lower carboxylic acids, lower amines, etc., and particularly preferable for the practice of the present invention are alcohols and glycols having 1 to 4 carbon atoms.

When the grafting reaction is carried out with a single solvent, it can be carried out by selecting only one kind from the first group of aqueous organic solvents. When using a mixed solvent, there are a case where a plurality of types are selected only from the first group of aqueous organic solvents, and a case where at least one type is selected from the first group of aqueous organic solvents and at least one type is added from the second group of aqueous organic solvents.

In both cases where the graft polymerization reaction solvent is a single solvent from the first group of aqueous organic solvents, and when it is a mixed solvent composed of one kind of each of the first and second groups of aqueous organic solvents. A graft polymerization reaction can be performed. However, there are differences in the progress of the grafting reaction, the appearance and properties of the grafting reaction product and the aqueous dispersion derived therefrom, and a mixed solvent composed of one of the first and second groups of aqueous organic solvents, respectively. It is preferable to use

In the first group of solvents, the copolyester molecular chains are in a state of extended chains, while in the mixed solvent of the first group / second group, they are entangled in a small-spread thread. This was confirmed by measuring the viscosity of the copolymerized polyester in these solutions. It is effective to prevent gelation by adjusting the dissolution state of the copolymerized polyester so as to prevent intermolecular crosslinking. Both high efficiency of grafting and suppression of gelation are achieved in the latter mixed solvent system. The weight ratio of the mixed solvent of the first group / second group is more preferably from 95/5 to 10/90, further preferably 90/10.
-20/80, most preferably 85 / 15-30 / 70
Range. The optimum mixing ratio is determined according to the solubility of the polyester used.

(Water Dispersion) The grafting reaction product according to the present invention is preferably neutralized with a basic compound.
By neutralizing, it can be easily dispersed in water. As the basic compound, a compound which volatilizes at the time of forming a coating film or at the time of baking and curing by adding a curing agent is desirable, and ammonia, organic amines and the like are preferable. Examples of desirable compounds include triethylamine, N, N-diethylethanolamine, N, N-dimethylethanolamine, aminoethanolamine, N-methyl-N, N-diethanolamine,
Isopropylamine, iminobispropylamine, ethylamine, diethylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, methylaminopropylamine, dimethylaminopropylamine, methyliminobispropylamine, 3-methoxy Examples thereof include propylamine, monoethanolamine, diethanolamine, and triethanolamine. The basic compound has a pH value of the aqueous dispersion in the range of 5.0 to 9.0 by at least partial neutralization or complete neutralization depending on the carboxyl group content contained in the grafting reaction product. Preferably, it is used as follows. If a basic compound having a boiling point of 100 ° C. or lower is used, the residual basic compound in the coating film after drying is small, and the adhesion to a metal or an inorganic vapor-deposited film, or the water resistance or hot water resistance of the laminate. Excellent adhesion.

In the aqueous dispersion produced according to the present invention,
The weight average molecular weight of the polymer of the radical polymerizable monomer is 500-
Preferably it is 50000. It is generally difficult to control the weight-average molecular weight of the polymer of the radical polymerizable monomer to 500 or less, and the grafting efficiency tends to decrease, and there is a tendency that the hydrophilic group is not sufficiently provided to the copolymerized polyester. is there. Further, the graft polymer of the radical polymerizable monomer forms a hydrated layer of the dispersed particles, but in order to provide a hydrated layer having a sufficient thickness and obtain a stable dispersion, The weight average molecular weight of the graft polymer is desirably 500 or more. Further, the upper limit of the weight average molecular weight of the graft polymer of the radical polymerizable monomer is preferably 50,000 from the viewpoint of polymerizability in solution polymerization. The control of the molecular weight within this range can be carried out by appropriately combining an initiator amount, a monomer dropping time, a polymerization time, a reaction solvent, a monomer composition or, if necessary, a chain transfer agent and a polymerization inhibitor.

In the present invention, the reaction product obtained by graft-polymerizing a radically polymerizable monomer onto a hydrophobic copolymerized polyester resin has a self-crosslinking property. Does not crosslink at room temperature,
With the heat during drying, 1) dehydration reaction of silanol groups present in the reactant 2) intermolecular reaction such as hydrogen abstraction reaction by thermal radicals, and cross-linking without a cross-linking agent. Thereby, the adhesiveness and water resistance, which are the objects of the present invention, can be expressed for the first time.
The crosslinkability of the coating film can be evaluated by various methods,
It can be determined from the insoluble fraction in a chloroform solvent that dissolves both the hydrophobic copolymerized polyester resin and the radical polymer. The coating film obtained by drying at 80 ° C. or less and heat-treating at 120 ° C. for 5 minutes preferably has an insoluble content of 50%.
%, More preferably 70% or more. When the insoluble content of the coating film is less than 50%, not only the adhesion and water resistance are not sufficient, but also blocking occurs.

The above graft copolymer can form an adhesion-modified layer which can be used in the present invention as it is, but can be cured by adding a crosslinking agent (curing resin) to the adhesion-modified layer. It can impart a high degree of water resistance.

Examples of the crosslinking agent include a phenol formaldehyde resin of a condensate of alkylated phenols and cresols with formaldehyde; an adduct of urea, melamine, benzoguanamine and the like with formaldehyde; An amino resin such as an alkyl ether compound composed of alcohol No. 6; a polyfunctional epoxy compound; a polyfunctional isocyanate compound; a blocked isocyanate compound; a polyfunctional aziridine compound; an oxazoline compound.

Examples of the phenol formaldehyde resin include, for example, alkylated (methyl, ethyl, propyl,
Isopropyl or butyl) phenol, p-tert
-Amylphenol, 4,4'-sec-butylidenephenol, p-tert-butylphenol, o-, m
-, P-cresol, p-cyclohexylphenol,
4,4′-isopropylidenephenol, p-nonylphenol, p-octylphenol, 3-pentadecylphenol, phenol, phenyl o-cresol, p
-Condensates of phenols such as phenylphenol and xylenol with formaldehyde.

Examples of the amino resin include methoxylated methylol urea, methoxylated methylol N, N-ethylene urea, methoxylated methylol dicyandiamide, methoxylated methylol melamine, methoxylated methylol benzoguanamine, butoxylated methylol melamine, and butoxylated methylol benzoguanamine. And methoxylated methylolmelamine, butoxylated methylolmelamine, and methylolated benzoguanamine.

Examples of the polyfunctional epoxy compound include diglycidyl ethers of bisphenol A and oligomers thereof, diglycidyl ethers of hydrogenated bisphenol A and oligomers thereof, diglycidyl orthophthalate, diglycidyl isophthalate, and the like.
Diglycidyl terephthalate, diglycidyl p-oxybenzoate, diglycidyl tetrahydrophthalate, diglycidyl hexahydrophthalate, diglycidyl succinate, diglycidyl adipate, diglycidyl sebacate, ethylene Glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether and polyalkylene glycol diglycidyl ethers, trimellitic acid triglycidyl ester, triglycidyl isocyanurate ,
1,4-diglycidyloxybenzene, diglycidylpropylene urea, glycerol triglycidyl ether,
Examples include trimethylolpropane triglycidyl ether, pentaerythritol triglycidyl ether, and triglycidyl ether of a glycerol alkylene oxide adduct.

As the polyfunctional isocyanate compound,
Low-molecular or high-molecular aromatic or aliphatic diisocyanates and trivalent or higher polyisocyanates can be used. Examples of the polyisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and trimers of these isocyanate compounds. Further, an excess amount of these isocyanate compounds and a low-molecular active hydrogen compound such as ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, or polyester polyols, Examples thereof include a terminal isocyanate group-containing compound obtained by reacting a polymer active hydrogen compound such as ether polyols and polyamides.

The blocked isocyanate can be prepared by subjecting the above isocyanate compound and a blocking agent to an addition reaction by a conventionally known appropriate method. Examples of the isocyanate blocking agent include phenols such as phenol, cresol, xylenol, resorcinol, nitrophenol, and chlorophenol; thiophenols such as thiophenol and methylthiophenol; oximes such as acetoxime, methyl etiketoxime, and cyclohexanone oxime. Alcohols such as methanol, ethanol, propanol and butanol; halogen-substituted alcohols such as ethylene chlorohydrin and 1,3-dichloro-2-propanol; t-butanol and t-
Tertiary alcohols such as pentanol; ε-caprolactam, δ-valerolactam, ν-butyrolactam, β
Lactams such as propyl lactam; aromatic amines; imides; active methylene compounds such as acetylacetone, acetoacetate ester, and malonic acid ethyl ester; mercaptans; imines; ureas; diaryl compounds; Can be mentioned.

These crosslinking agents may be used alone or in combination.
A mixture of more than one species can be used. The amount of the crosslinking agent is from 5 parts by weight to 4 parts by weight based on 100 parts by weight of the graft copolymer.
0 parts by weight is preferred. As a method of compounding the crosslinking agent,
(1) When the crosslinking agent is water-soluble, a method of dissolving or dispersing it directly in an aqueous solvent solution or dispersion of the graft copolymer, or (2) When the crosslinking agent is oil-soluble, after completion of the grafting reaction And a method of adding to a reaction solution. These methods can be appropriately selected depending on the type and properties of the crosslinking agent. Further, a curing agent or an accelerator can be used in combination with the crosslinking agent.

The above graft copolymer can form an adhesion-modified layer which can be used in the present invention as it is. For other purposes, a general-purpose polyester resin, urethane resin, acrylic resin, copolymers thereof, Various water-soluble resins and various functional resins, for example, a conductive resin such as polyaniline and polypyrrole, an antibacterial resin, an ultraviolet absorbing resin, and a gas barrier resin may be mixed to form an adhesion reforming layer. .

The adhesion-modifying layer may further contain additives such as various surfactants, antistatic agents, inorganic lubricants, organic lubricants, and ultraviolet absorbers as long as the effects of the present invention are not impaired.

[0043]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. In the examples, “parts” means “parts by weight”, and “%” means “% by weight”. Each measurement item followed the following method. (1) Film haze Surface haze was determined using a Poic integrating sphere type HTR meter SEP-H2D manufactured by Nippon Seimitsu Optical Co., Ltd. in accordance with JIS-K6714. (2) Evaluation of adhesiveness The laminated product was manufactured by Toyo Sokki Co., Ltd. “Tensilon UTM”.
2 "and peeled at 90 degrees with water, and measured by measuring the SS curve between the adhesion-modified layer and the base material.

Example 1 In a reactor equipped with a stirrer, a thermometer, a reflux device and a metered-dropping device, 75 parts of a copolymerized polyester resin (A-1), 56 parts of methyl ethyl ketone and 19 parts of isopropyl alcohol 19 were added.
Then, the mixture was heated and stirred at 65 ° C. to dissolve the resin. After the resin was completely dissolved, 15 parts of maleic anhydride was added to the polyester solution. Next, a solution prepared by dissolving 10 parts of styrene and 1.5 parts of azobisdimethylvaleronitrile in 12 parts of methyl ethyl ketone was dropped into the polyester solution at a rate of 0.1 ml / min, and stirring was further continued for 2 hours. After sampling for analysis from the reaction solution, 5 parts of methanol was added. Next, 300 parts of water and 15 parts of triethylamine were added to the reaction solution, followed by stirring for 1 hour.
Thereafter, the reactor internal temperature was raised to 100 ° C., and methyl ethyl ketone, isopropyl alcohol and excess ammonia were distilled off to obtain a water-dispersed graft polymer resin (B-1). The water-dispersed graft resin (B-1) was pale yellow and transparent.

The coating liquid was prepared by diluting the water-dispersed graft resin (B-1) with water: isopropyl alcohol = 9: 1 (weight ratio) so that the solid content concentration became 10%. Using 100% by weight of syndiotactic polystyrene (weight average molecular weight 300,000) as a lubricant with crosslinked polystyrene particles
Weight ratio of polymer chips containing 3.0% by weight, polymer chips containing 2.0% by weight to 100% by weight of syndiotactic polystyrene (weight average molecular weight 300,000) using crosslinked polystyrene particles as a lubricant and polymer chips not containing a lubricant. After mixing at a ratio of 1: 1: 1: 8, dried, melted at 295 ° C, extruded from a T-die with a lip gap of 200 μm, and adhered and cooled and solidified to a cooling roll at 40 ° C by electrostatic imprinting. A 55 μm amorphous sheet was obtained.

The amorphous sheet was first preheated to 98 ° C. by a roll, and four infrared heaters having a surface temperature of 750 ° C. were further heated. The film was stretched 3.3 times in the longitudinal direction at a film temperature of 140 ° C., and further heated to 120 ° C. The film is stretched 1.2 times in the longitudinal direction with a roll, and then subjected to a 12% longitudinal relaxation treatment between a ceramic roll at 150 ° C and a metal roll at 40 ° C. The film was further preheated to 110 ° C. by a tenter, stretched 3.5 times in the transverse direction at a stretching temperature of 120 ° C., and heat-set at 265 ° C. for 10 seconds.
Then, it was subjected to a 5% transverse relaxation treatment at 230 ° C., and further a 3% longitudinal relaxation treatment between a 220 ° C. ceramic roll and a 40 ° C. metal roll. A biaxially stretched syndiotactic polystyrene film having a thickness of 4 μm was obtained. The final coating agent application amount was 0.1 g / m ² . Table 2 shows the evaluation results of the obtained syndiotactic polystyrene film.

Example 2 Except that 8 parts of maleic anhydride and 17 parts of styrene were used,
In the same manner as in Example 1, a water-dispersed graft resin (B-2) was obtained. The water-dispersed graft resin (B-2) was pale yellow and transparent. A laminated syndiotactic polystyrene film obtained by laminating the water-dispersed graft resin (B-2) in the same manner as in Example 1 was obtained. Table 2 shows the evaluation results of the obtained syndiotactic polystyrene film.

Example 3 Instead of the copolymerized polyester resin (A-1), (A-
Using water-dispersed graft resin (B-
4) was obtained. The water-dispersed graft resin (B-4) was pale yellow and transparent. A laminated syndiotactic polystyrene film obtained by laminating the water-dispersed graft resin (B-2) in the same manner as in Example 1 was obtained. Table 2 shows the evaluation results of the obtained syndiotactic polystyrene film.

Comparative Example 1 Table 2 shows the evaluation results of the syndiotactic polystyrene film obtained in exactly the same manner as in Example 1 except that the film had no adhesion-modifying layer.

Comparative Example 2 In a reactor equipped with a stirrer, a thermometer, a reflux device and a metered-dropping device, 75 parts of the copolymerized polyester resin (A-1), 56 parts of methyl ethyl ketone and 19 parts of isopropyl alcohol 19 were added.
Then, the mixture was heated and stirred at 65 ° C. to dissolve the resin. After the resin was completely dissolved, a solution obtained by dissolving a mixture of 17.5 parts of methacrylic acid and 7.5 parts of ethyl acrylate and 1.2 parts of azobisdimethylvaleronitrile in 25 parts of methyl ethyl ketone at 0.2 ml / min. The mixture was dropped into the polyester solution, and stirring was continued for another 2 hours. After sampling for analysis from the reaction solution, 300 parts of water and 25 parts of triethylamine were added to the reaction solution and stirred for 1 hour. Thereafter, the reactor internal temperature was raised to 100 ° C., and methyl ethyl ketone, isopropyl alcohol, and excess triethylamine were distilled off to obtain a water-dispersed graft resin (B-5). The obtained resin (B-5) was pale yellow and transparent.
A laminated syndiotactic polystyrene film was obtained by laminating the water-dispersed graft resin in the same manner as in Example 1. Table 2 shows the evaluation results of the obtained syndiotactic polystyrene film.

[0051]

As described above, according to the present invention, a laminated syndiotactic polystyrene-based biaxially stretched film having excellent transparency and adhesiveness is obtained by adopting the constitution described in the claims. Provided.

[0052]

[Table 1]

[0053]

[Table 2]

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Keiji Mori, Inventor 2-1-1 Katata, Otsu-shi, Shiga F-term in TOYOBO RESEARCH CO., LTD. F-term (reference) EJ05C EJ37 EJ42 EJ98 GB15 GB27 GB41 JA07A JB06B JB06C JK06 JL11B JL11C JN01

Claims (3)

[Claims] 1. A self-crosslinkable polyester system in which one or more polymerizable unsaturated monomers are grafted on a hydrophobic polyester resin on at least one surface of a film made of a styrene polymer having a substantially syndiotactic structure. An easy-adhesive syndiotactic laminated with an adhesion-modified layer, which is a graft copolymer, wherein the graft copolymer contains at least one monomer containing an acid anhydride having a double bond. Polystyrene film. 2. A layer containing the self-crosslinkable polyester-based graft copolymer as a component, and a coating liquid containing the self-crosslinkable polyester-based graft copolymer is applied to an unstretched or uniaxially stretched film, and dried. The easily adhesive syndiotactic polystyrene-based film according to claim 1, wherein the film is further stretched uniaxially or more and then heat-set. 3. The easily adhesive syndiotactic polystyrene film according to claim 1, wherein the polymerizable unsaturated monomer contains at least maleic anhydride and styrene.