JPS5825958A - Polyester group composite film - Google Patents

Abstract

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

Description

Detailed Description of the Invention The present invention is a polyester film, particularly a polyester composite film with excellent printing ink adhesion.Recently, new demands have been met in applications such as food coloring, industrial parts packaging, and protective coatings. is increasing. In the food packaging field, hygiene aspects such as odorlessness and residual solvent content are being reviewed.
In reality, limitations on printing solvents, printing materials with good drying properties, etc. are becoming more important. For this reason, there is a demand for high-speed printing with printing inks for cellulose films.

Further, it is necessary that the printed layer does not peel off even when subjected to hot water treatment such as peeling off of the printed layer due to boiling treatment.

Also, in vacuum packaging and frozen food packaging, it is necessary to have flexibility due to deformation of the packaging material itself, solidification at low temperatures, etc. Pinholes may develop in the packaging material due to external force, or peeling between the base film layer and the printing layer may cause
Furthermore, the laminated easily heat-sealable material may peel off and lose its protective function as a film.

The above-mentioned boiling, V-tort treatment (high temperature sterilization), steaming treatment, etc. are performed under heating with water. At normal temperature.

Polyamide films are known to have a strong adhesive affinity under normal conditions, but under such conditions they may have enough properties to maintain their protective function, but their properties after hot water treatment are similar to that of water and heat. It is known that it gradually decreases due to deterioration. In order to provide packaging materials that can withstand these demands, we have arrived at the present invention as a result of intensive research.

That is, 5 the present invention uses dibasic acids (however, 80 of the dibasic acids)
At least one side of the base film layer made of a polyester composed of a glycol residue and a dibasic acid (at least 80 moles of the dibasic acid is terephthalic acid) A polyester (hereinafter sometimes abbreviated as terephthalic acid group polyester) composed of a glycol residue and a terephthalic acid-1e4-v chlorohexanedimetatool-based polyester described below. The surface layer is a stretched film formed from a mixed polymer, and the 11 mm IA is such that the terephthalic acid-1,4-cyclohexane dimetatool unit in the polymer has a KO of 05 to 100 (by weight) in the total mixed polymer.
The present invention relates to a polyester-based composite film, characterized in that the film surface of the mixed polymer layer in the film that occupies - is subjected to a corona discharge treatment.

In the above-mentioned terephthalic acid-1,4-cyclohexane V methanol polyester, at least 410 moles of the glycol component is L4-s'chlorohexanedimethanol X? The polyester is a polymer having a melting point of 260°C or less.

The polyester forming the base film layer used in the present invention is a dibasic acid (however, 80-@
It is a nine-polyester consisting of a terephthalic acid residue and a glycol residue. This dibasic acid residue is mainly a terephthalic acid residue, but 20 moles or less may be other dibasic acid residues. Examples include residues of isophthalic acid, phthalic acid, adipic acid, sepatic acid, succinic acid, V-oxic acid, etc., and residues of ox-V acids such as p-L dolo-V-benzoic acid may also be used. I can do it. In addition, glycol residues are common alkylene glycol residues such as ethylene glycol, propylene glycol, and trimethylene glycol.

Examples include residues such as tetramethyl V-glycol, hexamethylene glycol, V-chlorohexane, and V-methanol, but especially! l! A commercially available ethylene glycol or tetramethylene glycol residue is used.

Normally, the melting point of Telef, talic acid group polyester is 200℃
That's all. A particularly practical polymer is polyethylene terephthalate, and another is polytetomethylene terephthalate.

The film may be an unabrasive film, an axially abrasive film, or a biaxially stretched film. And its thickness is usually 5μ~50
It is 0j.

In the present invention, the polyester that is a component of the mixed polymer layer is a polyester (hereinafter referred to as polyester) composed of dibasic acid (however, 80 or more of the dibasic acids are terephthalic acid) residues and glycol residues. The dibasic acid residue is mainly a terephthalic acid residue, but up to 20 molar groups may be other dibasic acid residues. Basic acid residues include isophthalic acid, phthalic acid, adipic acid, sepatic acid,
There are residues such as succinic acid, V-oxalic acid, and p-hydroxy V
Residues of oxV acids such as benzoic acid can also be used.

In addition, the glycol residue is a normal alkylene glycol residue, and examples include residues such as ethylene glycol, fluoropylene glycol, trimethylene glycol, tetotumethylene glycol, hexamethylene glycol, etc., but especially in practical use. Typically, ethylene glycol or tetramethylene glycol residues are used. on the other hand,
Another component, terephthalic acid-1゜4-cyclohexane dimetatool based polyester, has at least 10 moles of the glycol component a difunctional glycol selected from the cis and trans isomers of 1,4-cyclohexanedimetatool. It is a polyester consisting of V carboxylic acid whose main component is terephthalic acid, and the melting point of the polymer is 2.
Refers to polymers that have a temperature of 60°C or less.

In this case, the terephthalic acid may be any terephthalic acid as long as it is suitable for film use, with particular limitations. It may contain isophthalic acid, albic acid, cepatic acid, phthalic acid, V-hydric acid, etc.

1$4-F hexane dimetatool is produced by catalytic reduction of dimethyl terephthalate or terephthalic acid, or is produced by decomposing a polyester having terephthalic acid units as an acid component with alcohol and glycol and simultaneously decomposing the acid component. The V isomer of hexane dimetatool and trans The body ratio is not particularly limited, but V-su body/trans body ratio is 4/6 to 0.
A range of /10 is preferred, in which case the bL4-y chlorhexanedimetatool can be used as a mixture with other glycols. In the case of nits, other glycol NKs include ether glycols such as diethylene glycol, triethylene glycol, as well as ethylene glycol, 1,5-pentane s't-t's LIO-decane V-ol and this kind of NK. 2~ like other glycols
There are polymethylene glycols with 10 carbon atoms. In addition, as side chain aliphatic glycol, %2.2-8
'Methyl-1,3-propane Vol, 2-methyl-1
, 5-bentanediol and the like. Carbocyclic glycols such as 1,4-di(oxyethyl)benzene can also be used. The L4-8/chlorohexanedimethanol-7-talic acid group polyester used in the present invention contains at least 10 moles of 1,4-cyclohexane dimetatool and 90 moles or less of other glycols. Such polyesters, preferably prepared by condensing terephthalic acid with up to 50 moles of other dicarboxylic acids, range from melting points as low as about 100°C to as low as about 330°C. ℃
A polymer having a high melting point can be obtained, but k to achieve the object of the present invention is at least 260°C or lower.

Preferably, highly polymerized polyesters that melt at 240° C. or lower are useful. If the melting point of the 114-F chlorohexanedimethanol-terephthalic acid group polyester exceeds 260°C, it will not only be difficult to process the compound with the terephthalic acid group polyester, but also have insufficient other properties as a packaging film. Printability after corona discharge treatment is also poor. Sara KFi
When coextrusion is employed as a means for obtaining the composite film of the present invention, extrusion moldability may be reduced.

Used in the present invention. The film laminated on the base film is made of a polymer mixed with the terephthalic acid-based polyester and the above-mentioned 141e4-V chlorohexanedimethanol-terephthalic acid group polyester, and is stretched at least uniaxially, preferably biaxially. It is what it is. L4 contained in the total mixed polymer forming the film
-szChlohequinane V methanol - The total proportion of the terephthalic acid group polyester is 0.5 to 100% by weight (in the total mixed polymer), and this content is less than 0.5% by weight! D effect is not sufficient.

The method of adding and mixing the terephthalic acid group polyester to the terephthalic acid group polyester to produce the mixed polymer layer of the composite film of the present invention is the polymerization of the terephthalic acid group polyester. At the end of the polymerization, L4-$/Chlohequinane V was added to the polymerization system.
Method of adding polyester consisting of methanollute V phthalic acid, terephthalic acid group polyester chips and L4-
A method of forming a film after mixing sz chlorohexanedimethanol lute V7 talic acid group polyester chips with a grinder, a method of adding 1,4-cyclohexanedimethanol terephthalic acid group polyester immediately before molding the terephthalic acid group polyester, etc. However, it is also possible to combine these methods. The mixed polymer mixed in this manner can be prepared by conventional polyester film forming methods such as T-die method, Inflation V! It can be formed into an unstretched film using a stretching method. t+, it may be laminated and extruded by a coextrusion method with the polymer forming the base film of the film of the present invention,
Alternatively, the unstretched film laminate may be obtained by extruding the films separately from independent gooses and then immediately laminating them.

The laminated unstretched film can be subjected to a grinding process.

Alternatively, it can be extruded onto a rolled uniaxially stretched film forming the base film of the present invention and then stretched in the rear right angle direction. The effects of the present invention are more effectively exhibited by a film obtained by subjecting an unstretched film of this mixed polymer to at least uniaxial stretching, particularly preferably biaxial stretching. The stretching temperature can be almost the same as in the case of a film containing only terephthalic acid group polyester, but if the blending amount of 5L4-s' chlorohexanedimethanol-terephthalic acid group polyester is high, the stretching temperature may be changed and polishing performed at 9 temperatures. The stretching temperature is usually 70 to 100°C. Although the stretching temperature is an important condition for achieving the effects of the present invention, it is necessary to perform at least uniaxial stretching, and especially biaxial stretching. is preferred. The grinding magnification is not limited, but in the case of uniaxial stretching, it is 1.2 to 6 times, preferably 1.5 to 6 times.
It is usually about 1.2 to 6 times larger in the horizontal direction. In the case of a non-stretched film, the functionality as a packaging material is poor, and the above-mentioned txi due to L4-v chlorohexanedimethanol-terephthalic acid group polyester formulation
The features of the present invention are demonstrated. When laminated with the base film forming layer in an unstretched state, sanding can be performed in the same manner.

The adhesion between the mixed polymer film layer and the base film layer is good, and when a laminated film is formed by coextrusion and then stretched, the K1 polymer layer is extruded and laminated on the unstretched intermediate film of the base film, and then stretched. In both cases, even when the mixed violet composite layer is extruded onto a uniaxially stretched base film and then stretched, the adhesion is good and strong adhesive force is obtained without the need for an adhesive. Of course, there is nothing wrong with using ordinary adhesives. 9-axis stretching, -axial stretching.

A polished mixed polymer film may be laminated on a biaxially stretched base film.

The mixed polymer film layer has inferior transparency when compared to, for example, a polyethylene terephthalate film.The higher the proportion of K 114-V chlorohexane dimethanol-terephthalic acid group polyester in the mixed polymer film, the lower the transparency. However, the transparency is improved by stretching, and especially when laminated with a base film layer, the transparency is further improved.

Moreover, since it is in a laminated state, the thickness of the mixed polymer film layer can be suppressed to about 1, which does not have self-supporting properties, so that it is possible to further improve the apparent transparency.

The thickness of the mixed polymer film can be determined as appropriate depending on the use of the laminated film, but is usually 1μ to 100μ.
μ.

After two-wheel stretching, the film is subjected to a corona discharge treatment on at least one side of the mixed polymer film layer in a known manner. It is well known that corona discharge treatment is applied to improve the printability and adhesion of ordinary polyester films.
With this alone, it is not possible to achieve the pleasant improvement in printability as in the present invention, and in the absence of the corona discharge treatment in the present invention, the effects of the present invention cannot be obtained. In short, in the present invention, a satisfactory improvement effect cannot be obtained without either the specific resin composition or the corona discharge treatment.

The corona discharge treatment was carried out using a commercially available discharge treatment machine to flatten the layer containing the 1,4-cyclohexanedimethanol-terephthalic acid group polymer, treatment current, and voltage.

It is preferable to adjust the treatment temperature, atmospheric gas composition, etc. so that the water droplet contact angle of the treated film is 70 degrees or less.

Therefore, the corona li3 of the film of the present invention! [The surface is usually 70
It has a water droplet contact angle value of less than 1°.

The film of the present invention has improved adhesion to cellophane ink, which has been considered a drawback of conventional two-wheel abrasive polyester films, and has the excellent properties of polyester films, with particularly excellent mechanical properties. and a two-wheel stretched polyester film having heat resistance.

Therefore, the film of the present invention can be easily subjected to various processing treatments, and is extremely useful in a wide range of applications including packaging. In addition, cellophane ink refers to printing ink containing nitrified cotton as a binder, and generally refers to commercially available inks for printing cellulose cellulose film (cellophane) K. Normally, the nitrification degree is 9 to 12.5- and the polymerization degree is 20 seconds to 1/20 seconds by the Vercules method, which indicates the characteristics of nitrified cotton.In addition to this nitrified cotton, polyamide resin 1 synthesis Rubber, adine, ester rubber such as glycerin ester, urea, amine resin such as melamine It 81 etc. are used in combination, but inorganic or organic pigments and dyes are further used in the above-mentioned nitrified cotton-containing mixture, which is not limited to these. For example, titanium white, yellow lead, copper powder, phthalocyanine blue, etc. can be used as appropriate depending on one color. These mixtures are diluted with solvents such as alcohols, esters, and ketones, and various organic solvents such as penzole, doluol, ethyl acetate, benzene, and quinolene to adjust the viscosity before use. Furthermore, volatile fest etc. are used as a coloring agent.

The amount of printing ink layer when printing on the surface of a film made of a mixed polymer is usually 0.05 to 15 f/d.

Preferably it is 0.1-51/d. The printing ink further contains stabilizers, plasticizers, weathering agents, natural resins, rubber derivatives,
Additives such as a lubricant and a gloss-imparting agent 1 may be contained in appropriate amounts. Note that 9% of the mixed polymer film is used to form a printing ink layer on the film surface.

The surface may be treated in advance by a known and publicly used means such as flame am, acid JJ & coral, etc. In particular, it was hidden that the adhesion to the printing ink layer was improved by the surface treatment.

Even at any K, the mixed polymer film and the printing ink layer are sufficiently firmly bonded, and printing can be performed in the same manner as conventional cellophane printing.

Conventional polyester films, such as tungsten polyethylene terephthalate films, cannot be printed with printing inks containing nitrified cotton as a binder. As the printing method, various roll coating methods such as gravure roll method, kiss roll method, bar code method, reverse roll method, etc., as well as blade coating, dip coating, spray soot method, etc. are used.

In the composite film of the present invention, dyes, pigments, antistatic agents,
Of course, additives such as ultraviolet absorbers and lubricants may be mixed.

Examples will be shown below to specifically explain the present invention, but
The present invention is not limited in any way by these Examples.

Note that the method for measuring characteristic values in the present invention is as follows.

(1) Adhesiveness (adhesiveness to the IjIh polymer layer ink layer) (a) Tape release Use a commercially available adhesive tape (trade name: cellophane tape) to attach it to the printing ink layer side to avoid air bubbles. The peeling condition when quickly peeled off was classified and evaluated as follows.

Okin <　IfJ can't let go! L likes.

O hardly peeled off, good condition.

(10- or less) Δ 10 to 50 - Peel off. Slightly poor.

x 5p16 or more - almost completely @ release. Bad.

The film was placed between two fingers with the printing ink layer on the inside, and the film was rubbed 5 to 6 times to check the degree of peeling.

Evaluation is same as above.

Scratching Printing was carried out by scratching on cardboard with a thickness of 1z so that the printing ink layer was on the upper side.The degree of shedding of the ink layer was investigated. The evaluation is as follows.

O It does not fall off at all and is in good condition.

O hardly falls off and is in good condition.

Δ Slightly falling off. Slightly poor.

× Easily falls off. Bad.

(2) Boiling property test A sample was placed in hot water at normal pressure and 95°C, boiled for 30 minutes, and then taken out and cooled to measure each characteristic.

(3) Water droplet contact angle measured in a constant temperature room with a temperature of 20°C using a contact angle measuring device made by Elma Optical Co., Ltd. - A water droplet was dropped onto the film surface from a micro syringe, and the diameter and height of the water droplet was measured. The water droplet contact angle was calculated according to the following formula.

1≧90@ #-90・+'*slnam -1(
Contact angle rI water droplet radius hI water droplet height) Examples 1 to 5 Terephthalic acid 41 parts (1 mol) % 114- V Clohexane V Methanol 19.5 parts (0.35 mol).

39.5 parts (1,654 parts) of ethylene glycol and H-D
0.054 lu of an IG inhibitor and 0.054 lu of germanium oxide as a catalyst were placed in an autoclave, heated and transesterified with stirring, and then polycondensed to obtain a polymer. Polyethylene terephthalate with an intrinsic viscosity of 0.60 and the above copolymer were mixed so that the former and the latter were in the ratio shown in Table 1, while only PET was melted and the respective flows were combined inside a T-die and discharged. After cooling, the thickness ratio mixed polymer ms+
A pg'r layer 7), a 120μ unpolished film was obtained. This unsharpened stretched film was stretched by 3.3 times in the machine direction K at 85°C, then by 3.3 times in the transverse direction at 95°C, and further heat-set at 210°C for 10 seconds.

The thus obtained two-wheeled whetstone film was manufactured by Yukinai Denki Co., Ltd.:!
A corona discharge treatment was performed on the surface of the mixed resin layer of the composite film at room temperature at a high voltage of 23 volts and a current of 8.6 A using a discharge discharge machine. Apply the following printing ink uniformly to these films using a Mayer bar.Cf1l type 2
'/') Printability was measured after Lh drying. The water droplet contact angles of these films before and after corona treatment were measured. The results are shown in Table IK.

For comparison, a biaxially abraded polyethylene terephthalate film 't-obtained fF- (comparative example 1 film) was obtained under the same conditions using polyethylene terephthalate and having a thickness of 12 μm.

Printing ink: Nitrified cotton 70 (weight) s, polyamide 30 (
(weight) -, and then combined with a warm solution of methanol, toluene% n-p-p-p-p-p-p-p-p-p-pyl alcohol to give a solid content of 70 parts.
A mixture of 5 parts.

As described above, the film of the present invention had excellent adhesion to printing ink, and had good adhesion even after the boiling test.

On the other hand, Comparative Example 1 had almost no adhesion with printing ink;
Separation occurred between the printing ink layer and the film.

Furthermore, Comparative Example 2 is the same film as Example 3, but was not subjected to corona discharge treatment, and this case also shows that the adhesive force with the printing ink is insufficient.

Patent applicant: Toyobo Co., Ltd. 325-

Claims (1)

[Scope of Claims] At least one surface of the base film layer made of a polyester composed of dibasic acid (80 moles or more of the dibasic acid is terephthalic acid) residue and glycol residue Basic acid (80 mol of the dibasic acid)
The following terephthalic acid-
1゜9 surface layer stretched film formed from a mixed polymer containing 4-V chlorohexane dimethanol polyester, and terephthalic acid-L4 in the surface layer mixed polymer.
-V clohexane dimetatool units are K in the total mixed polymer
A polyester composite film characterized in that the film surface of the mixed polymer layer is subjected to a corona discharge treatment in a film containing O05 to 100% (by weight). Terephthalic acid-L4-V chlorhexanedimetatool kite polyester contains at least 10 moles of the glycol component.
4-s' Rita hexane dimethanol chloride, and the melting point of the polyester is 260°C or lower.