JPS60192630A - Polyester 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 relates to a polyester film, and more specifically:
This invention relates to a polyester film suitable for thermal transfer materials.

In recent years, with the advancement of office automation, various recording methods have been developed, and among these, the thermal recording method, which produces less noise during printing and is easy to operate, is attracting attention.

Normally, a thermal recording method is used in which recording is performed by directly contacting a thermal head with thermal recording paper containing a special coloring agent. Although this method improves the operability and maintainability of the heat distributing device, the recording paper is easily discolored by heat and heat, and there is a problem with long-term storage of records. Recently, the thermal transfer recording method has been gaining attention as a method that takes advantage of the advantages of the thermal recording method and eliminates the above disadvantages.Thermal transfer recording method can print on plain paper9.
Problems with long-term storage of records and poor print quality
For these reasons, it is thought that various typesetting printers &C will be used in the future. Examples of printers include computer printers, word processor printers, video printers, label printers, still video camera printers, and facsimile machines. Furthermore, the development of computers in recent years has been remarkable, with the introduction of the iC, which makes it easy to display color graphics, and the era of color printers.

In this method, a thermal transfer material consisting of a base material and a thermal transfer layer coated on its surface is used.For printing, recording paper (generally plain paper can be used) and Thermal transfer layer of thermal transfer material! ＆Touch, apply pressure, touch the thermal head to the opposite side of the base material, and heat the thermal head with a pulsed current on the head. A heat m1 ink layer is transferred or a sublimation ink is sublimated from only the thermal transfer layer in the heated and cooled portion, and transfer recording is performed onto a recording paper. Usually, the heat bath meltable ink layer has an ink temperature vth.

It is easily transferred to recording paper at a temperature range of C-/0C, and the sublimable ink sublimes and transfers at an ink temperature range of 70C to 0C. Generally, the method using the former is called the fire-melting type thermal transfer method, and the method using the latter is called the sublimation type thermal transfer method.

We recommend a heat-fusion type thermal transfer method, and for solid black printing, we use a thermal transfer material with carbon black added to the ink layer.
To create color, heat-sensitive transfer materials for the three primary colors of yellow, magenta, and cyan are prepared separately, and the three primary colors are layered by thermally transferring them three times, once for each color, onto the same recording paper. .

On the other hand, a major feature of the sublimation heat-sensitive transfer method is that the step a14 can be easily produced. In other words, the advantage of sublimating ink violet is that it is easy to control the amount of heat from the thermal head. If possible, lower the applied voltage or shorten the application time of the current pulse. Taking advantage of the fact that nIaPl can be easily produced, this method is applied to color printing, especially color printing of N@ figures and photographic tools. The method for color printing is similar to thermal fusion, in which thermal transfer materials in the three primary colors of yellow, magenta, and cyan are prepared.
This is a method in which thermal transfer is performed once for each color, totaling three times.

The introduction of the sublimation type heat-sensitive transfer method, as mentioned above, requires a further increase in the amount of heat in the head in order to transfer the color, and the heat-sensitive transfer material is exposed to a higher temperature than the thermal fusion method. . When using sublimation ink in thermal transfer, a special image-receiving nozzle is sometimes provided on the recording paper for color stability and maintainability, but in general, the thermal transfer method uses plain paper. Since it can be easily recorded, the disadvantages of the thermal recording method can be eliminated.

Conventionally, condenser paper has been used as the base material for thermal transfer materials, but it is weak and easy to tear, and in order to obtain faster printing and clearer images, the base material must be made thinner. However, when using capacitor paper, the thickness is
(Due to the difficulty of reducing stains and spots, it has been proposed to use a thin film of plastic as the base material.

By the way, when using a glass film as a base material, the following phenomenon of stickiness occurs, which poses a serious problem in its use.

That is, during recording, the surface temperature of the thermal head exceeds the melting point of the base plastic film, and the film in contact with the thermal head fuses to the thermal head, resulting in a stick phenomenon in which the feeding of the thermal transfer material is hindered. occurs. The sticking phenomenon can cause the recording to lose its clarity, cause the fused film to make a loud noise as it is forcibly removed, and in severe cases, the vehicle may stop running.
This may cause operational problems.

The stick phenomenon is particularly common in sublimation type thermal transfer materials where the temperature of the thermal head is low.

As a method to prevent this sticking phenomenon, a method of providing a protective layer on the N in contact with the thermal head was proposed in JP-A No. 3;3.
According to the knowledge of the inventor of JP-A-7II & No. 7, JP-A Akiki, the conventional method is based on the premise of coating on the stretched film of two wheels, and uses an organic heating medium, so # agent p
There are problems such as the i6 beam problem and high cost.

In view of the above facts, and in order to obtain faster and still Psm recording, the present inventors have developed a method that uses substrates that do not cause the stick phenomenon even when the thickness is made thinner, and the stick phenomenon in sublimation thermal transfer using a warm thermal head type. As a result of searching for a method to inexpensively produce a base material that does not cause the occurrence of oxidation, the invention was found to be non-inventive.

In other words, the gist of the present invention is that at least one side of the polyester film is coated with a fluorine-based # emulsified or mixed in water.
(-) mixed with aqueous molecules and/or reactive small molecules dissolved, emulsified or suspended in water; or (b) mixed with aqueous molecules and/or reactive small molecules dissolved, emulsified or suspended in water. Alternatively, the polyester film may be coated with a reactive low-molecular-weight lid through an undercoat layer provided thereon. Due to the adhesive and slippery properties of the polyester film, it does not transfer to the opposite side of the film, making it ideal as a layer for preventing the sticking phenomenon of heat-sensitive transfer materials.

Below is a detailed explanation of the misfire 8A.

The polyester of the present invention is a crystalline linear saturated polyester formed from an aromatic dibasic acid or its ester-forming conductor and a diol, and includes polyethylene terephthalate, polyethylene inphthalate, and polyethylene terephthalate. , polyethylene-11, 6-naphthalate, and the like. Also, it does not matter even if a part of the film is a separate container. Normally, dilatational polyester film sheets are formed from inorganic particles such as calcium carbonate, kaolin, and silica, and residues of catalysts used in reactions. A film with improved blocking properties containing precipitated particles can be used.

When this film is used as a heat-sensitive transfer material, the film thickness is preferably about 20 μm to −0 μm. If it is thin, productivity will be poor, and if it is thick, there will be no advantage of using a polyester film. - When manufacturing thermal transfer materials, a thermal transfer layer is provided on the opposite side of the film to which it is applied, but at this time static electricity builds up on the film. This may cause coating unevenness, resulting in a serious problem that the thermal transfer layer cannot be coated uniformly. In order to determine such a period of PA, it is preferable to use polyester which has been subjected to a tetanic acid prevention treatment by a known method. For example, there is a method in which 1 m of sulfone salt, represented by the following formula, is continuously incorporated into polyester. C of
Indicates an alkyl group of 8 to ago, and Me is an alkali metal or an alkaline earth metal. ) Such compounds include sodium octylsulfonate, sodium decylsulfonate, sodium dodecylsulfonate, modified sodium octylbenzenesulfone, sodium dodecylbenzenesulfone, potassium dodecylbenzenesulfonate, sodium nonylnaphthalenesulfone, and sodium dodecylnaphthalenesulfone. Examples include sodium, dodecylnaphthalene sulfone potassium, etc.

These chemical vlJs can be used alone or in combination with koji or more.

Examples of the fluorine-based T# resin used in the present invention include vinyl fluoride resin, vinylidene fluoride fat, trifluorochloride ethylene w fat, tetrafluoroethylene resin, tetrafluoroethylene-hexafluoropropylene resin, Ethylene-tetrafluoroethylene copolymer porridge, ethylene-trifluorochloride ethylene co-KL 8
411 JJ'd, tetrafluoroethylene-perchloroalkyl vinyl ether copolymer Oat fats, etc.Fluorocarbon complexes are applied to the film as an emulsified or turbid water dispersion in water, but water dispersion The product can be obtained by methods such as dispersing fluororesin using a powdered surfactant and emulsifying fluorine vinyl monomer in water.
L.

The molecule it of the fluororesin is not particularly limited.

The particle size of the imitation particles in the aqueous dispersion is 0.0! rpm~3θμm
and when large particles are present in the aqueous dispersion,
It is used after being removed by sedimentation, centrifugation, filtration, etc.

The undercoating layer is coated with water-free polymer and/or reactive low-molecular-weight polymer or I@selected water-based polymer and/or reactive low-molecular-weight polymer and/or reactive low-molecular weight polymer. Layer.

The aqueous polymer used in the present invention includes water-soluble,
There is no particular restriction as long as it is an aqueous molecule that can be emulsified or suspended. Examples of such aqueous polymers include the aqueous polymers described in TLC, "Water-soluble Polymers, Water-Dispersible Resin General Conference Technical Plans and Results" edited by Management Development Center Publication Department (published on January 3, 1981), etc. Starch, cellulose fibers such as methylcellulose and hydroxyethylcellulose, alginic acid, gum arabic, gelatin, sodium polyacrylate, polyacrylamide, polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone, urethane m JJ
Examples include aqueous polymers that dissolve, emulsify, or cloud in water, such as li, acrylic resins, ether thread resins, epoxy resins, and ester-based resins.

In particular, water-based polymers with good adhesion to polyester films are preferred, and urethane resins, acrylic resins,
More preferably, it is an ether thread resin or an epoxidized molecule. This is because, via the functional groups, the polymer can crosslink to form a hard polymer, producing a film that is adhesive and does not transfer to the opposite side.

As the urethane resin, water-based urethane resins can be used, whose construction cost components include polyisocyanates, polyols, chain extenders, and redness agents. A common method is to use an extender with a hydrophilic group introduced into it. Another well-known method is to react the unreacted incyanate groups of polyurethane with a compound having a hydrophilic group. As such a urethane resin, the urethane m resin described in Japanese Unexamined Patent Publication No. Sho Str-7g7t/etc. can be used.

For acrylic resins, the main components are alkyl acrylate and/or alkyl methacrylate reacted with carboxyl groups or their salts, choic acid anhydride groups, sulfonic acid groups or their salts, amide groups, amino groups, hydroxyl groups, epoxy groups, etc. This can be achieved by using a water-based acrylic resin copolymerized with a vinyl monomer having a specific functional group. In particular, water-based acrylic resins containing carboxyl groups, epoxy groups, amino groups, etc. are preferred in order to improve adhesion to biaxially stretched polyester films and coating film strength. An example of such an appendage is ``Unexamined Patent Application Publication i+8. tza-
lkoda6. Compounds disclosed in Publication No. t/ can be used.

The ether thread resin of the present invention means polyalkylene glycol. Specifically, polyethylene glycol,
Examples include polypropylene glycol, polytetramethylene glycol, conjugate of ethylene oxide and propylene oxide, and conjugate of ethylene oxide and tetrahydrofuran. Molecules of these polyalkylene glycols M hi o” P-701
11 is good. If the molecular weight is low, the coating film will become sticky, so it is preferable to cure the coating film by appropriately crosslinking it. As the crosslinking agent, compounds containing epoxy groups, blocked isocyanates, methylolated melamines, etc. can be used.

Examples of ester resins include aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, and their ester-forming derivatives, aliphatic carboxylic acids such as adipic acid, azelaic acid, and sebacic acid, and their ester-forming derivatives. G') Cole, Globylene Glycol, /,
Reactants with diols such as 4I-phytanediol, 44-cyclohexane dimetatool, diethylene glycol, and polyethylene glycol can also be used. A well-known method is to co-mix a compound having a sulfonic acid group with the above components to make it aqueous. Dicarboxylic acids and
Alkali metal or alkaline earth metal salts such as ester-forming derivatives of et al.

As the polyvinylpyrrolidone, pure polyvinylpyrrolidone f or copolymerized with styrene or other vinyl monomers can be used.

The above-mentioned reactive low molecular weight substance in the present invention includes:
Epoxy compounds, acrylic acid fermentation conductors, melamine compounds,
Incyanate compounds can be used, which are ultimately still molecularized after application to the polyester film. Epoxy compounds include those containing two or more epoxy groups,
Derivatives of polyalkylene glycols can be used. For example, a compound represented by the formula n (wherein R represents a substituent such as hydrogen, a methyl group, or an isopropyl group, and n has a value of /-100) can be used.

The aqueous polymer and the reactive low molecular weight substance can be used in combination.

In the present invention, water is used as a solvent for the coating solution, but in addition to water, alcohols such as methanol, ethanol, and isobutylene may be added.

When applying a mixture of a fluororesin and an aqueous polymer and/or a reactive low molecular weight substance, the proportion of the fluororesin in the solid content should be at least 10%, preferably 10 to 90%. The ratio should be 2O-Jrθ, more preferably 2O-Jrθ.If this ratio is too small, the lubricity will not be exhibited.
However, if you use too much MU'IM, the disadvantage of seeing the reflective surface once is overcome.

When a water-based polymer and/or a reactive low molecular weight substance is applied to provide an undercoating JVj, and a fluororesin layer is provided on top of it, the ratio of fluororesin in the solid content of the entire coating is 1. The number of multiplications should be at least 1, preferably 1 to 1.
%, more preferably 5 to gθ point.

The total coating thickness of the present invention is O, OSμ ~ 3μ and f.
Ru. Preferably 0. /μ~2μ. If the thickness is too thin, the lubricity will be poor, and if it is thick enough, it is not necessary to have a thickness greater than n.

The coating liquid may be added with a surfactant to improve its applicability to polyester films. As the surfactant, anionic, cationic, or nonionic surfactants can be used. In the present invention, the method of applying coating e is a well-known method that can be applied thinly. Any method may be used, and methods such as a rod coater, a gravure coater, and a roll coater are used.

The coating may be applied to a biaxially stretched film, or may be applied to the surface of the film before oriented crystallization is completed, and then subjected to stretching heat treatment.

The effects of the present invention will be even more effective if a method is used in which a water dispersion is applied to a polyester film of which crystal orientation is completed = l+, followed by drying and heat treatment to complete crystal orientation. For example, the sequential biaxial stretching method involves coating a longitudinally-axially oriented polyester film with the water dispersion or water bath solution, drying as appropriate, or without drying, and then stretching in the transverse direction in a scissor tenter with moving clips. This method involves heat treatment. This method makes it possible to lay the fabric layer and dry it at the same time as stretching, which simplifies the operation.
Moreover, since it is stretched after coating, the coating film can be easily made thin.

The heat treatment temperature in the above method is preferably about 1 to 50C. K, which forms the storm cloth layer into a strong coating film, requires high heat, and in the method of coating a biaxially stretched film with 7:1, Kn is treated with such high heat, and the equipment normally used is used. Furthermore, a device to prevent heat shrinkage of the film is required. However, with the above method, 1% heat treatment can be easily performed, and the adhesion to polyester film is excellent, and the lubricity is also significantly superior.
In addition, it is possible to produce a polyester film in which the coating JID does not affect the opposite side. The transfer layer used in the present invention is composed of a colorant and a binder. In the case of heat-melting thermal transfer method 1. As the colorant, pigments such as carbon black and various dyes widely used in the copying field can be used.As the binder, carnauba wax, montan wax, microcrystalline wax, wood wax can be used. , oil-based synthetic wax, etc. can be used.

In the case of sublimation type thermal transfer method, colorants include sublimable dyes such as azo dyes and anthraquinone thread dyes, and binders include carboxymethylcellulose, methylcellulose, ethylcellulose, nitrocellulose, alginic acid derivatives, polysulfone, and polyethersulfone. .

Examples include polyarylate and polyethermamide.

In the present invention, if the adhesion of the fluororesin layer or transfer layer to the polyester film is poor, the polyester film may be subjected to corona treatment or subbing coating treatment.

According to the present invention, a heat-sensitive transfer material that does not cause the sticking phenomenon χ can be obtained, and furthermore, the strength of the base film is increased. Therefore, even if the plastic film is made thinner, it is less likely to wrinkle (and tear), making it easier to handle as a thermal transfer material.

The present invention will be explained 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" means "part by weight". Viscosity Measurement 1 Measurement of surface roughness and evaluation of the heat-sensitive transfer material were performed as follows.

Measurement of viscosity: Polyester film'+! Dissolve in θOml of a mixed solvent of i'& phenol/tetrachloroethane = / / / (weight ratio).

Measure the viscosity at 30°C.

Measurement of surface roughness: Place the film on the table Koita Research Institute■
Using a reptile three-dimensional phase measuring device, the radius of the needle is -〇μ, the load is 30
Under 1n90 conditions. -/11111/ See across the film surface Y 2- k tan IIC at a speed of 100 times the reference length direction 1 surface roughness direction ysoooo
Zoom in twice and plot the roughness curve. From the roughness curve, extract a portion of measurement length L in the direction of its center line, and when this is removed, express the value given by the following formula in μm.

When measuring, the cutoff value is 00 parts.

Measure 12 points and calculate the average value for 70 points excluding the maximum and minimum values.

Reviews of thermal transfer materials We used a typewriter EP-CO made by Brother Electronics Co., Ltd., and a typewriter made by Brother Electronics Corporation. OO
The test was carried out using a dual head that can be changed up to C.

The aqueous polymer and fluorine fiber resin used in this example are as follows.

[Water-based urethane type W collapse]

Impranil DLli (manufactured by Bayer AG (trade name)) containing 3% by weight of sodium sulfonate groups and containing hexamethylene diisocyanate as a product was used.

[Water-based acrylic thread fat]

An acrylic emulsion containing acrylic acid, methyl methacrylate, and methacrylic acid as main components was used. The method for synthesizing this resin is as follows.

Sodium lauryl sulfate a-Ss dissolved in 51 parts of acrylic acid ether, 410 parts of methacrylic acid methyl, methacrylic kick part, dodecyl mercaptan aS part, and 1 part of water was homominated in a blender to obtain a monomer premix emulsion.

This premixed emulsion and at part of ammonium persulfate dissolved in 75 parts of water were each separately added dropwise into 117 parts of water over 3 hours to carry out a reaction at 75-gO<0>C. After the exposure was completed, the reaction was maintained at gOC for another 3 minutes to complete the reaction and latex was obtained.Next, this latex ytroc was mixed with Mk, and in this was dispersed magnesium oxide consisting of a magnesium oxide a part and a water part. The reaction solution was stirred for lj minutes at the same temperature, and -1% aqueous ammonia was added, and the pH of the reaction liquid was adjusted to 1 lj.
Adjust the lc and let it mature for 30 minutes.The solid content is 30.
Obtain a heavy water dispersion.

[Aqueous ester price decline]

Terephthalic acid, isophthalic acid! A polyester consisting of -ndium sulfoisophthalic acid, ethylene glycol, and diethylene glycol was used. The method for synthesizing this 4I71 fat is as follows.

Dimethyl terephthalate, dimethyl isophthalate,!
- Sodium sulfodimethel isophthalate, ethylene glycol, and diethylene glycol were placed in a reactor, and an ester conversion reaction was performed using calcium acetate hydrate. After the transesterification reaction was completed, phosphorus was added and polymerized with antimony trioxide under reduced pressure. The obtained polyester was poured into hot water to obtain an aqueous dispersion. 'ix2, the obtained polyester has an acid component Sθ molar ratio of terephthalic acid, a 7 molar ratio of inphthalic acid, a 7 molar ratio of 5-ndium sulfoiphthalic acid, and a glycol component of 60 mole ratio of ethylene glycol, [Fluorine-based resin] Tetrafluoroethylene copy a (average diameter -〇θ~Product name/) was used.

Examples 7 to 3 A stretched polyethylene terephthalate film having an intrinsic viscosity of atO and having precipitated particles formed from calcium, lithium, and phosphorus and having a thickness of 9 μm and a diameter of 9 μm was coated with Teflon. An aqueous dispersion obtained by mixing the aqueous resins listed in Table 1 with the compounding ratios listed in Table 1 was coated with a bar coater to obtain a coated film with a thickness of approximately 0.5 μm. . On the opposite side of the coating film of the film, 10 parts of carbon black was added to the coating film.
) 4IO@, Melt coat j, thermal transfer material was obtained by applying a heat-fusible ink consisting of AW fatty acid ester wax O part at a coating amount of about daf/m'@This thermal transfer material is a type made by Kebrother. When one ridge was curved with the writer EP-CO, no sticking phenomenon was observed and good printing was achieved.

Example 5 2g of polyethylene terephthalate, which has a hard-shoulder viscosity of 066 and is made of amorphous silica with an average diameter of lSμ, was melt-extruded at 5°C and placed on a cooling drum of tOC. Cast, then stretch 3.S times vertically.This a
An aqueous dispersion prepared by mixing Teflon and the aqueous resin listed in Table 1 at the distribution ratio listed in Table 1 was added to one side of the i-stretched film. Coat with a bar coater so that it becomes f/-,
Subsequently, the film was stretched 37 times in the transverse direction at l/ρC and heat-set at x3oC. The thickness of the obtained film was 6μ.

When the same evaluation as in Example 1 was performed, no stick phenomenon was observed at all.

Example 6 A coating film was prepared in the same manner as in Example 1, and on the opposite side, an anthraquinone dye PTR-&JC Mitsubishi Chemical Co., Ltd., which was dispersed in an isopropyl alcohol solution of ethyl cellulose, was applied.

A sublimation type heat-sensitive transfer material was obtained. When the heat-sensitive transfer material was evaluated at different temperatures, good printing could be performed when the temperature of the transfer layer was between iao<0>C and 0<0><0>C.

Moreover, no stick phenomenon was observed.

Comparative example 1 Example 1 except that no coating film was provided.

Evaluation was made in the same manner as in Example 1. The film did not run due to the stick phenomenon.

Comparative Example λ Evaluation was carried out in the same manner as in Example 1 except that the Teflon particles were omitted. The film did not run due to the stick phenomenon.

Claims (1)

[Claims] (1) On at least one side of the polyester film,
A fluorocarbon resin emulsified or suspended in water (ml) is mixed with a reactive low molecular weight polymer and/or a water-based polymer which is dissolved, emulsified or clouded in water (b) water. A polyester film characterized in that it is coated with an undercoat layer formed by coating an aqueous polymer and/or a reactive low molecule accumulator dissolved, emulsified or suspended in a polyester film. .