JPS59179554A - Readily adherent polyester film - Google Patents

Abstract

PURPOSE:The titled film that contains a block-copolymerized polyester which is prepared by adding ethylene oxide to both chain-end hydroxyls of PTMG, thus showing improved adherability to hydrophilic and lipophilic binders without any adverse effects on its clarity. CONSTITUTION:The objective biaxially oriented polyester film contains 0.1- 10wt%, preferably 0.3-5wt% of a block copolymer between poly(oxytetramethylene) glycol and poly(oxyethylene)glycol which is prepared by adding ethylene oxide to both terminal hydroxyls of poly(oxytetramethylene) glycol chains, has a molecular weight of 500-50,000. The molecular weight of the PEG on one terminal of the PEG-PTMG block copolymer is preferably more than 100.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a biaxially oriented polyester film with excellent adhesive properties.

Biaxially oriented polyester film, especially biaxially oriented polyethylene terephthalate film, has good transparency, dimensional stability,
Photosensitive materials and drawings that have excellent mechanical properties, heat resistance, electrical properties, gas barrier properties, chemical resistance, etc., and use packaging materials, electrical insulation materials, metal vapor deposition materials, silver salts, diazo compounds, photosensitive resins, etc. It is used as a base material for other materials, electrophotographic materials, and magnetic recording materials.

In these applications, biaxially oriented polyester films are required to have adhesive properties. For example, for packaging materials, adhesion with printing inks, laminating materials, and vapor-deposited metals, for photosensitive materials, adhesion with photosensitive layers with binders such as gelatin and polyvinyl alcohol, and for magnetic recording materials, adhesion with magnetic layers, etc. requested.

As one method of improving adhesiveness, a method is known in which polyalkylene glycols are contained to obtain a biaxially oriented polyester film. (Unexamined Showa S/-ri 3θ5
Ko, JP-A-53-10/θ & ff, and JP-A-Sho glI-
qaqq3) That is, it is a method of making polyester contain poly(oxyethylene) glycol (hereinafter abbreviated as PEG) or poly(oxytetramethylene) glycol (hereinafter abbreviated as PTMG) to obtain a biaxially oriented polyester film. .

According to the findings of the present inventors, although adhesion can be improved by incorporating PEG or PTMG, there are drawbacks in either case. In the case of polyester containing PEG, the contact angle of water droplets is reduced and the adhesion to a laminate having a hydrophilic binder or ink is improved. Furthermore, since PEG is easy to polymerize, it is possible to produce substances with various molecular weights, from low to high molecular weight substances, and by selecting a substance with an appropriate molecular weight, it is possible to improve the adhesion without impairing the transparency of polyester. can. However, PEG has the disadvantage that it has poor adhesion with hydrophobic coating agents and laminating materials, and that peeling occurs at the adhesive interface when treated with hot water. If the amount of PEG is increased to compensate for these drawbacks, the drawbacks will be that thermal stability and transparency will be impaired.

On the other hand, in the case of a polyester film containing PTMG, it exhibits good adhesion to organic solvent-based coating agents and other lipophilic laminates. However, due to its polymerizability, it is difficult to obtain a high molecular weight version of PTMG.
Polyester containing G has poor thermal stability and causes difficulties in handling such as film formation. However, the biaxially oriented polyester film I containing PTMG has a drawback of poor transparency.

The present invention takes advantage of the advantages of containing PEG and PTMG, improves the disadvantages, and contains less polyalkylene glycol, thereby creating a hydrophilic binder and lipophilic binder with good transparency. The purpose of the present invention is to provide a biaxially oriented polyester film with improved adhesion to a typical binder.

SUGA 1 The present invention is a block copolymerized polyether component (hereinafter referred to as PEG-PTMG block copolymer) of PTMG with ethylene oxide added to both terminal hydroxyl groups of PTMG and PEG having a molecular weight of hoo ~; o, o o o. This invention relates to a biaxially oriented easily adhesive polyester film containing 0.1 to 70% by weight of 0.1 to 70% by weight.

The polyester of the polyester film of the present invention has polyethylene terephthalate in a proportion of not less than go weight ratio of its constituent components. In addition to ethylene terephthalate, the polyester component in the polyester film according to the present invention includes isophthalic acid, co-, 6-
Dibasic acids such as naphthalene dicarboxylic acid, diphenylsulfone dicarboxylic acid, diphenoxyethane dicarboxylic acid, diphenyl dicarboxylic acid, sodium sulfoisophthalate, adipic acid, sebacic acid, azelaic acid, and their derivatives Sokyokumi≠, neopentylene gellicol, /, cucyclohexanediol, /,
Examples include glycols such as cucyclohexane dimetatool, 4'-bisoxyethoxybenzene and diethylene glycol, and oxycarboxylic acids such as P-β-oxyethoxybenzoic acid.

The PEG-PTMG block copolymer can be produced by adding ethylene oxide to PTMG using an alkali catalyst, but is not limited to this method. PTMG used in PEG-PTMG block copolymer
The molecular weight of is preferably 1.300-A;0θO, more preferably soo~3000. If the molecular weight of PTMG is lower than 3θO, it is difficult to exhibit the characteristics of PTMG even if it is contained in a polyester film, and if the molecular weight is higher than 500, the dispersibility in polyester is poor, resulting in a biaxially oriented polyester. The transparency of the film decreases. The molecular weight of the PEG-PTMG block copolymer is
SOO~5θ, 000, even better l'ig
oo~20.000. When the molecular weight of the PEG-PTMG block copolymer is lower than SOO, the adhesion of the polyester film is low, and the molecular weight is r o, o o
If the o is also high, the transparency and adhesiveness of the polyester film will decrease. The ratio of the PEG component and PTMG component of the PEG-PTMG block copolymer depends on the application! 1
There are cases in which the characteristics of PKG are the main feature and cases in which the characteristics of PTMG are the main feature, and although it cannot be defined unambiguously, PEGOt
In order to exhibit the ff properties, it is preferable that the molecular weight of PEG at one end is at least ioo or more.

The terminal group of the PEG-PTMG block copolymer is preferably a hydroxyl group, but it may also be a derivative in which one or both ends are alkoxylated or glycidylated.

The content of the P Ej G - P T M G block copolymer in the polyester film is 0.7 to 10 parts by weight, preferably 0.3 to 3 parts by weight. Content is 0.7
If the amount is less than 10% by weight, no effect of improving the adhesion of the film will be observed, and if it exceeds 10% by weight, the transparency and mechanical properties of the film will decrease.

The meaning of containing a PEG-PTMG block copolymer in a polyester means that when a PEG-PTMG block copolymer is copolymerized into a polyester as a polyester-forming component, a polyester obtained by copolymerizing a PEG-PTMG block copolymer is This means when the PEG-PTMG block copolymer is blended into a general polyester, when the PEG-PTMG block copolymer is blended into a general polyester without being copolymerized with the polyester, or a combination thereof. PEG-
Specific methods for incorporating the PTM () block copolymer into polyester include methods for incorporating it during the transesterification or esterification reaction during polyester production, during the polymerization reaction, and immediately before the completion of the polymerization reaction; , a method of incorporating it during melt extrusion, or a method of combining the various methods mentioned above.

The biaxially oriented polyester film of the present invention is.

It is obtained by melt-extruding the above-mentioned polyester to obtain an unstretched film, and then performing biaxial stretching by sequentially or simultaneously biaxially stretching in the longitudinal and transverse directions, and then heat-setting. Stretching temperature jd70~/koθC
1. The stretching ratio in both the length and width is usually from λ to 100%, but it is also possible to use a re-stretching method. The heat setting temperature is 0 to 1Ior; for a period of several seconds to 7 minutes.

The thickness of the biaxially oriented film of the present invention is appropriately selected depending on its use, but is usually between 0.mu. and 700 .mu.m.

Preferably, the thickness is μ to 200 μ.

The feature of the present invention is that a block copolymerized polyether of poly(oxyethylene) glycol and poly(oxytetramethylene) glycol with a molecular weight of soo to o and θ0θ is used. By containing the polyalkylene glycol (1) by increasing the amount of polyalkylene glycol, adhesion with hydrophilic inks and hydrophobic binders is improved.

(2) High transparency of the film.

The point is that this effect can be demonstrated.

The biaxially oriented polyester film of the present invention may contain a stabilizer, an antifoaming agent, a lintability improver, an antistatic agent, an anti-coloring agent, etc., as necessary. Furthermore, if necessary,
It is also possible to perform corona discharge treatment or plasma discharge treatment.

The biaxially oriented polyester film of the present invention is.

Because it has good adhesive properties, it can be used as is for various purposes, but it must be coated on one or both sides beforehand.

By laminating resins and metals by coextrusion, lamination, vapor deposition, etc., it can be used for various purposes after improving adhesion, heat sealing properties, gas barrier properties, antistatic properties, etc.

EXAMPLES The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to the following Examples unless it exceeds the gist thereof. In the examples, “part” is “
Parts by weight. In addition, the methods for measuring physical property values in the following examples are as follows.

Tensile test Using Tensilon UTM-1 manufactured by Toyo Baldwin, the length was 39 mi at 20t11'' and temperature 65%.
A phaseless film with width/jfm is pulled at 200 m/min, and the following values are determined from the load-elongation curve.

Breaking elongation: Elongation relative to one piece length at break.

Represented by .

Breaking strength: The value obtained by dividing the load required to break the film by the unit cross-sectional area of the original film. Expressed as ky, /mi.

It is determined using an integrating sphere type hydrometer NDH-20D manufactured by Nippon Denden Kogyo ■ in accordance with the film base J-K S-K 67/G. The smaller the value (correspondence), the higher the transparency.

Toyo Ink Manufacturing ■Printing ink for Cerocolor 00ST
39 indigo was applied to the surface of the film so that the coating thickness after drying was HaSμ, and dried with hot air at goC for 1 minute to obtain a film for evaluation.

The temperature and humidity of the evaluation film was controlled for 2 hours at 10 C1 and 4J% humidity, and a length of 7 m was applied to the ink-applied surface of the film using cellophane tape (/, fmm width) made by Nichiban Co., Ltd. to prevent air bubbles from entering. Apply a constant load on this with a 3ky manual load roll.Fix the film and attach one end of the cellophane tape to the top.

Connect to the weight of 1, and the weight becomes 'I! c′m distance is evaluated by a method in which a peel test in the / f 00 direction is started after free fall. Adhesion is evaluated and displayed using the following S-stage criteria.

Evaluation: Ink does not peel off from the cellophane tape surface at all.

Rating 'I: Less than 10% of the ink peels off from the cellophane tape surface. Practically speaking, it can be used without problems as long as it is on the evaluation grid.

Evaluation 3: /o-r The ink in the o% portion peels off to the cellophane tape side.

Rating 2:j! ; 0% or more of the ink peels off to the cellophane tape side.

Evaluation: The ink was completely peeled off to the cellophane tape side.

A magnetic layer is applied to the polyester film of the present invention, and the peel strength is measured. The composition of the magnetic paint forming the magnetic layer is: polyurethane SO part, nitrocellulose 20 parts, salt pea vinyl acetate resin 30 parts, incyanate compound 7.5 parts, carbon black 12 parts, lecithin q part, γ-Fθ, 0, 116
0 parts of methyl ethyl ketone, toluene, and methyl imbutyl ketone were dispersed in qoo parts of a solvent. A magnetic layer is applied to the polyester film using a coater so that the thickness after drying is 5 μm, dried at go'6 for 7 minutes, and then aged at θC. After drying, the film is cut to a width of /h inch and used as a sample for adhesion measurement.

Adhesiveness was measured by pasting the sample on Scotch tape manufactured by Sumitomo 3M ■ and Tenshi4 U manufactured by Toyo Baldwin ■.
This is done by peeling into a T shape using a TM-1 type.

Examples 1 to 2 and Comparative Examples/Co (Production of PFfG-PTMG block copolymer) Molecule f
Ethylene oxide is added to poly(oxytetramethylene) glycol with f, g 00 and 1 soo using an alkali catalyst to produce poly(oxyethylene)-poly(oxytetramethylene)-poly(oxytetramethylene) with an overall molecular weight of about θθO. An ABA type block copolymer polyalkylene glycol of ethylene) was produced. In the following examples, these two types of block copolymers are PEG=PTMG.
(A) and PEG-P'l'MG (B).

P E G P T M G (A) p Molecular weight g
001) Block copolymer PEG-PTMG (B) with ethylene oxide added to both ends of PTMG and a total molecular weight of goθθ; molecular weight 7.00 (1) PTM
Add ethylene oxide to both ends of G to reduce the total molecular weight to g
Block copolymer with oC0 (method for producing polyester copolymer) 90 parts of dimethyl terephthalate, ethylene glycol &
4 parts and 0.1035 parts of calcium acetate hydrate were placed in a transesterification reactor, heated and raised in temperature, methanol was distilled off, and the temperature was raised to 230C over a period of approximately 3 hours to complete the transesterification reaction. Next, this transesterification product was transferred to a polymerization reaction tank, and while being held at 2'IO'Q,
3 parts of phosphoric acid O1θ, 70 parts of PEG-PTMG block copolymer, 0.03 parts of antimony trioxide! Add i part,
After about 1 hour by reducing the pressure and increasing the temperature, a polyester copolymer having a reduced viscosity of about θ, gs was obtained.

(Film-forming method) A polyethylene terrescrete containing o, o g weight% of Fuji Tevison's Cleft Thyroid 266 and the above polyester copolymer are mixed, and the PEG-PTM in the mixture is mixed.
The G block copolymer was made to have a weight percentage of O,OS from 10 to 10% by weight.

After drying, the mixture was melt-extruded at 1.2grr3 to obtain an unstretched film with a thickness of 750μ, and then stretched at 3.5grr in the machine direction.
Double roll stretching, then transverse direction using a tenter 3. After stretching by g times, heat treatment was performed at 230C to obtain a biaxially oriented film with a thickness of 2μ.

Table 1 shows the relationship between the content of the PEG-PTMG block copolymer in the polyester and mechanical strength, film base, ink adhesion, and magnetic layer adhesion. For comparison, a polyester film containing no polyalkylene glycol was also evaluated.

In Examples 1 to 7, ink adhesion and magnetic layer adhesion were able to be improved without impairing mechanical strength or film base.

Comparative Example / did not contain any PEG-PTMG block copolymer, and Comparative Example λ had a small amount of the PEG-PTMG block copolymer, so the ink adhesion and magnetic layer adhesion were poor.

Comparative Examples 3 to 6 Copolymers of poly(oxyethylene) glycol having a molecular weight of xgθ00 and poly(oxytetramethylene) glycol having a molecular weight of S00 with a polyester were obtained in the same manner as in Examples 1 to 7, and polyalkylene glycol in the polyester was obtained. were mixed so that the amounts were as shown in Table 1, and a film was formed.

Systems using poly(oxyethylene) glycol have little effect on improving the adhesion of the magnetic layer, and systems using poly(oxytetramethylene) glycol have little effect on improving ink adhesion, or the film base is inferior. was.

Claims (1)

[Claims] (1) Block copolymerization of poly(oxytetramethylene) glycol with a molecular weight of 30 θ to SO, θ 00 with poly(oxytetramethylene) glycol in which ethylene oxide is added to both terminal hydroxyl groups of poly(oxytetramethylene) glycol. The polyether component is 0. /-/θ weight%
A biaxially oriented easily adhesive polyester film comprising: