JPS5821430A - Polyester film having improved printability - Google Patents

Abstract

PURPOSE:The titled film, obtained by incorporating a specific amount of a specified terephthalic acid-cyclohexanedimethanol polyester in a terephthalic acid polyester, molding the resultant mixture, and subjecting the surface of the molded article to the corona discharge treatment, and having improved printability. CONSTITUTION:A mixture prepared by mixing (A) a polyester consisting of 80mol% or more dibasic acid component containing 80mol% or more terephthalic acid and a glycol component, e.g. ethylene glycol, with (B) a polyester, having a melting point <=260 deg.C, and consisting of a glycol component containing 10mol% or more 1,4-cyclohexanedimethanol and an aromatic dicarboxylic acid component containing preferably 100mol% terephthalic acid, and containing 0.5-90wt%, preferably 1.0-20wt%, terephthalic acid 1,4-cyclohexanedimethanol units is molded into a film. At least one side of the resultant film is then subjected to the corona discharge treatment to give the aimed film.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a preester film, especially a preester film with excellent printing ink adhesion. Recently, new demands have been made in applications such as food packaging, industrial parts packaging, and protective coatings. It's increasing. In food packaging public funding, hygiene aspects such as odorlessness and residual i-steel content are being reviewed.
Because printing solvent limitations, drying, etc. are actually becoming more important, there is a demand for high-speed printing with printing inks for cellulose-based films.

In addition, it is necessary that the printed layer does not peel off due to hot water treatment, such as peeling off of the printed layer due to boiling treatment.
Even in frozen food packaging, it is necessary to have flexibility due to the packaging material of the film itself, curing at low temperatures, etc. If the packaging material develops pinholes due to external force, or the base film layer and the printed layer peel off, the easily laminated heat-sealing material will peel off and lose its protective function as a film. #ILi! lll or retort treatment (high temperature bite fungus)
Steam treatment and the like involve heating with water. Meliad-based films are also known to have strong adhesion affinity at room temperature and under normal conditions, but it is unclear whether they have any properties that maintain their protective function at all under such conditions, and their properties after hot water treatment are similar to that of water. It is known that it gradually decreases due to the deterioration effect with heat. 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, the present invention deals with dibasic acids (however, among the dibasic acids, aO
By a mixed electropolymer containing the following terephthalic acid-1,4-sitagastric ester in a polyester composed of a terephthalic acid residue and a glycol residue, terephthalic acid-1,4-Schiff's gastrointestinal unit in the mixed polymer is 0.5 to 0.5 to 100% in the total mixed polymer.
This is a polyester film with excellent printability, characterized in that at least one side of the film has a weight of 90 (weight) and is subjected to a discharge treatment.

The terephthalic acid-1,4-hexanedimetatool-based preester contains at least 10 moles of the glyfur component.
is an ester as long as it consists of a bifunctional glycol residue which is a glycol selected from the cis or trans isomer of 1,4-hexanedimetatool and an aromatic dicarboxylic acid residue mainly consisting of terephthalic acid, and The polyester is a polymer having a melting point of mao'c3 or less. Also, the preester used in the present invention is a polymer having a dibasic acid (however, 80 moles or more of the dibasic acid is terephthalic acid) residue and It is a ester (hereinafter abbreviated as terephthalic acid-based ester) composed of glycol residues. The dibasic acid residues are mainly terephthalic acid residues, but 80% or less may be other dibasic acid residues. Other dibasic acid residues include isophthalic acid, 7
Examples include residues such as tarric acid, adipic acid, cepatic acid, cohelic acid, and oxalic acid. Some residues of oxyacids such as sulfate benzoic acid can also be used.

Glycol residues are ordinary alkylene glycol residues, and examples include residues such as ethylene glycol, tetrapyrene glycol, trimethylene glycol, tetramethylene glycol, and hexamethylene glycol. Use ethylene glycol or tetramethylene glycol residues. on the other hand,
Another component, terephthalic acid-1,4-Schiff's ester, is such that at least 10 moles of the glycol component is a glycol selected from the cis or trans isomers of Hesicle's ester. A polymer consisting of a bifunctional dalicol residue and an aromatic dicarboxylic acid residue mainly consisting of terephthalic acid, and the melting point of the ester is tSO°C or less. In this case, the aromatic dicarboxylic acid is mainly terephthalic acid, but less than 50 moles, preferably g
.

The moles ≦ or less may contain other dibasic acid residues such as isophthalic acid, adipic acid, cepatic acid, succinic acid, heptatalic acid, oxalic acid, and the like. Of course, 100 moles of terephthalic acid is preferred.

The 1,4-situgastric hexane dimetatool used in the present invention is produced by catalytic reduction of dimethyl terephthalate or terephthalic acid, or is produced by decomposing a dilyester containing terephthalic units as an acid component with alcohol or glycol and simultaneously acidifying it. O can be produced by any method, such as one obtained by catalytic reduction of the component terephthalic acid ester.
The ratio of the cis isomer to the trans isomer of the No. 1s-stomach hexane dimetatool is not particularly limited, but it is preferably in the range of cis isomer/trans isomer 4/6 to O/10. In this case, a mixture of 1,4-citohexanedimethanol and other drugs can be used. This is as stated above. Examples of other glycols used in this case include ethylene glycol, 1,8-bentanediol, as well as ether glycols such as diethylene glycol, silyethylene glycol, etc.
1.10-Decanediol and other glyfurs of this group include methylene dalycol as long as it contains ~10 or more carbon atoms Other side-chain aliphatic glyfurs include, s! -Dimethyl-1,3-Pudapandiol, Lazy-
Includes methyl-1,B-bentanediol and the like. 1.
Carbocyclic glycols such as 4-di(oxyethyl)benzene can also be used. Terephthalic acid-1,4-terephthalic acid-1,4-terephthalate-based preesters are 1,4-di(oxyethyl)benzene and dimethane. or 1. A mixture of 4-citogastric hexane dimetatool and other glycols as described above with terephthalic acid (or its derivatives).
It can be produced by a known method by condensing a mixture with. I to terephthalic acid-1,4-cyclo used in the present invention? Nandimethanol-based polyester contains a glycol component consisting of at least 80% 114-situ hexane dimetatool (no #100) and up to 0 mole of other difunctional glycols (O-SO%); SO (mol) is terephthalic acid and up to 50 mol of other difunctional dicarboxylic acids (o-
It is preferable to produce it by condensation with a dicarlphinic acid component consisting of ao%). The above-mentioned terephthalic acid-citogastric hexane dimetatool M+1 reester can be used to obtain a polymer having a melting point as low as about 100 υ to a high melting point of about 330 tl, but in order to achieve the object of the present invention, it is preferably at least 160°C or lower. Highly polymerized polyesters that melt at temperatures below 40°C are useful. If the melting point of the pre-7-talic acid-1,4-cyccyhexane dimenol ester exceeds 260°C, it will be difficult to process the polymer when mixing it, and other properties will be poor as a packaging film. Not only is this insufficient, but the printability after the discharge treatment is also poor.

The film of the present invention is obtained by adding terephthalic acid, l,4-cytanoyl-hequinane dimethanol-based ester to the above-mentioned terephthalic acid-based polyester, and stretching the mixture at least uniaxially, preferably 8
It is made by axial stretching.

The proportion of terephthalic acid-1,4-Schiff-tetrahexene dimethanol units contained in the total mixed polymer forming the film is in the range of O,S to eog, preferably 1.0. - g o weight - This content is 0.1
If the weight is too low, the effect will not be sufficient, and even if it is added in excess of 90% by weight, the effect will hardly increase, and on the contrary, adverse effects such as deterioration of the tensile properties and other physical properties of the film will occur.・If the pre-7thalic acid-1,4-sitane unit and the pre-7thalic acid-1,4-sitane unit in the total mixed polymer are within the above range, the terephthalic acid-based glycyester and terephthalic acid-based glyceryl ester and terephthalic acid-based
Although the mixing ratio with the 1,9-cyclohexanedimethanol-based preester is not particularly limited, the mixture of the pre-7thalic acid-based l-lyester and the terephthalic acid-1,4-cyclohexanedimethanol-based preester The ratio is usually 99
, 410) to 10190 (weight ratio). However, in order to reduce the change in the mechanical properties of the film produced only with terephthalic acid polyester,
914 + 0.6 to 'F 0130 (li weight ratio is preferably in the range).

In producing the film of the present invention, terephthalic acid-1
, 4-Sita p-hexane dimetatool-based polyester is added to the terephthalic acid-based polyester. There are methods such as forming a film after mixing polyester chips and terephthalic acid-i,4-sitadihexanedimethanol-based polyester chips in a blender, and adding them immediately before forming the terephthalic acid-based polyester. A combination is also possible. The mixed polymer mixed in this way can be used in the usual l-diester film forming method, for example! - Can be formed into an unstretched film by die method, blown sheet method, etc. The effect of the present invention is that this unstretched film can be
This effect is more effectively exhibited by a film obtained by axial stretching, particularly preferably by 8-axis stretching. The stretching temperature can be almost the same as that for terephthalic acid-based preesters, but if the blended amount of terephthalic acid-1,4-preester is high, stretching may be performed at a different temperature. I can't help it. The stretching temperature is usually 'y
It is o-100°C. Stretching is an important condition for exerting the effects of the present invention, and at least one wheel stretching is required, and biaxial stretching is particularly preferred. There are no restrictions on the stretching method, but in the case of uniaxial stretching, 1.
8 to 6 times, preferably 11 to 7 times, and in the case of 8-wheel stretching, 1.8 to 1 times in the longitudinal direction and 1.8 times in the transverse direction. II
It is usually about 7 times as much. In the case of a film that is not stretched, its functionality as a packaging material is poor and the features of the present invention are difficult to exhibit.

The film after axial stretching is subjected to axial discharge treatment by a known method. It is well known that a series of electrical discharge treatments are performed to improve the printability and adhesion of ordinary polyester films, such as PRE-ethylene Tele 7 Tarley F.
With this alone, it is not possible to achieve the significant improvement in printability as in the present invention, and in the present invention, the effect of the present invention cannot be obtained if the electric discharge treatment is absent.

In short, in the present invention, even if either the resin composition or the electric discharge treatment is lacking, no significant improvement effect can be obtained.

Four discharge treatment uses a commercially available discharge treatment machine and adjusts the treatment current, voltage, treatment temperature, atmospheric gas composition, etc. so that the water droplet contact degree of the treated film is 70 degrees or less. It's good to do it. Therefore, the corona discharge treated surface of the film of the present invention usually has a water droplet contact angle value of less than 'FO degree.

The film of the present invention has improved adhesion to printing inks, which was considered to be a drawback of conventional biaxially stretched ester films, and also has the excellent properties of a stretched ester film. Ueda ink is a biaxially stretched ester film with excellent mechanical properties and heat resistance. Commercially available ink cartridges that print on 4 ^^ belong to this category. More specifically, the ink has a nitrification degree of 9 to 1.
The degree of polymerization at 5- indicates the characteristics of nitrified cotton.The viscosity according to the Kieres method is usually between go seconds and 1780 seconds.
Ester rubbers such as gin, glycerin ester, urea, amine resins such as melaquine resin, etc. are used in combination, but are not limited to these. Further, inorganic or organic pigments and dyes are used in the above-mentioned mixture containing nitrified cotton, such as titanium white, yellow lead, copper powder, lid ν shea blue, etc. 0, which is used by seeding with various organic solvents such as ketone solvents, penzole, tool, ethyl acetate, benzene, quinolene, etc., and adjusting the viscosity.In addition, volatile fest etc. are used as a vehicle. The amount of the printing ink layer when printing on the film surface made of mixed polymers is usually O,OS ~ 1 sfl/♂, preferably 0.1-1 f/d, which is more stable to the printing ink. agents, weighting agents, weathering agents, natural resins, rubber derivatives, lubricants,
Appropriate amounts of additives such as gloss imparting agents may be used in some cases. ◎When forming the printing ink layer on the surface of the mixed electrolyte film, the surface must be treated in advance by publicly known means such as flame treatment or acid treatment. It has also been found that the adhesion to the printing ink layer can be further improved by surface treatment.

In any case, the mixed polymer film and the printing ink layer are sufficiently firmly bonded, and moreover, printing can be performed in the same manner as conventional paperback printing.

Conventionally, ester films such as polyethylene terephthalate films cannot be printed with printing inks containing nitrified cotton as a binder.

As the printing method, various types of printing methods such as the gravure sealing method, the printing method, the perfoot method, and the reverse sole method, as well as the blade coating, dip coating, and spray coating methods, can be used.

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.

Margin below Examples are shown below to specifically explain the present invention.

1. The method for measuring characteristic values in the present invention is as follows.

(1) Adhesiveness (adhesiveness between the mixed polymer layer and the printing ink layer) Tape release: Using a commercially available adhesive tape (trade name: SEISHIHEN TAPE), paste the printing ink layer in such a way as to avoid any bubbles. The peeling condition when applied and quickly peeled off was classified and evaluated as follows.

◎ No peeling at all. Good.

O hardly peeled off, good condition. (10% or less) Δ 10th attack - sod peeling/slightly defective/X Completely KMIII over SO% or more.

Defective (b) Rub The film was placed between 83 fingers with the printing ink layer on the inside, and the film was rubbed 15 to 6 times.

The evaluation was the same upper 〇 (c) ta] S. The print ink layer was placed on the upper side of the 1 % thickness, and the slipping was settled to examine the dropout of the ST1 print ink layer. The evaluation is as follows: ◎ No dropouts at all. Good.

○ is 0 good with almost no falling off.

Δ Slightly falling off. Slightly poor.

× Easily falls off. Bad.

(2) Boiling test A sample was placed in hot water at normal pressure and 98°C, boiled for 30 minutes, and then taken out and cooled to measure each characteristic. (6) In a constant temperature base with a water drop contact angle temperature of 20°C. The measurement was performed using a Goniome Teiichi type contact angle measuring device manufactured by Elma Optical Co., Ltd.

Water drops! A water droplet was dropped onto the film surface using a syringe, the diameter and height of the water droplet were measured, and the contact angle of the water droplet was calculated according to the following formula.

(θ tactile angle r: radius of water droplet hz height of water droplet) When mixing polymers, use a suitable antioxidant, ultraviolet! i! There is no problem in incorporating additives such as absorbents, lubricants, pigments, etc.

When producing the film of the present invention, there is no problem in applying heat treatment to the stretched film.Example 1. /-5L 41 parts of terephthalic acid, 19°6 parts of l,4-cyclohexane dimetatool, 39.6 parts of ethylene glycol and D
0.05 mole of IG inhibitor and 0.05 mole of Yium oxide gel as a catalyst were placed in an autoclave and pre-thermal transesterified with stirring, followed by polycondensation to form l,4-cyclohexane dimetatool and terephthalate. A polyester (onT&S!-) consisting of acid was obtained. Polyethylene terephthalate having an intrinsic viscosity of 0.60 and the above-mentioned polyester were mixed so that the former and the latter were in the proportions shown in Table 1, and melt-extruded under the following conditions to obtain an unstretched film having a thickness of XtOμ.

Next -, asg vertically 3°5x, then horizontally 9x
The biaxially stretched film thus obtained was stretched by s4 times at 8°C and further heat-set at 210°C for 10 seconds. Discharge treatment was performed manually (at room temperature).
The following printing ink was uniformly applied to these films using a Mayer bar (solid content El/d) I, and after drying, the printability was evaluated, and the results are shown in Table 1. In addition, Table 1 shows the results of measuring the water droplet contact angles of these films before and after the four-way discharge treatment.

Printing ink 1 nitrified cotton 0 (weight>%, yv a!id SO
(weight) ≦, and then mixed it with a mixture of methanol, toluene, and 1-1 Tabil alcohol so that the solid content is 200 parts, and 8 parts of titanium white.
A mixture of 6 parts.

For comparison, an axially stretched polyethylene terephthalate film (Comparative Example L film) was obtained under the same conditions using polyethylene terephthalate and having a thickness of 1 μm.

As mentioned above, the film of the present invention has excellent adhesion with printing ink, and has good adhesion even after the boiling test. Adhesion was very poor, and the film peeled off between the printing ink layer and the film.The comparative example is the same film as in Example 2, but was not subjected to the four-discharge treatment. Even in the absence of discharge treatment, the adhesion to printing ink is shown to be insufficient.

Patent applicant: Toyobo Co., Ltd.

Claims (1)

[Claims] Dibasic acid (provided that aO mol-acid-1 of the dibasic acid,
It is a film sculpted by a mixed polymer containing 4-sic stomach hexane dimetatool, lj & lyester,
and d to terephthalic acid-1,4-cyta ν in the mixed polymer.
F Sandemetatool leather position is O, a ~ SO (
An ester film with excellent printability, characterized in that at least one side of the film has been subjected to a discharge treatment of 2% by weight. Terephthal-1.4-Shitahe Life Sandi Metatool-based polyester is a preester consisting of a dalicol component, at least a difunctional dalicol residue which is coal, and an aromatic dicarboxylic acid residue mainly consisting of terephthalic acid. And the preester is a polymer whose melting point is ago°C or lower.