JP2677583B2 - Substrate film for thermal transfer recording - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a base film for heat-sensitive transfer recording, and more particularly, to a base film effective for a heat-sensitive transfer recording film that is compatible with high-speed printing.

(Prior Art) Generally, in a thermal recording device such as a thermal printer,
The recording paper and the heat-sensitive transfer coloring layer of the heat-transfer recording film ribbon are brought into contact with each other, and the film is selectively heated by a pulse signal from the heating head on the side opposite to the color layer, and the color layer heated through the film is melted. , Is transferred to recording paper.

The film ribbon for heat-sensitive transfer recording used in this thermal recording device has conventionally used capacitor paper or the like as a base material, but if the input time to the heating head is shortened in order to speed up recording, the base material is used. There was a problem because I had to speed up the heat transfer. For example, when trying to reduce the thickness of the base material in order to speed up heat transfer, thin paper such as condenser paper has low mechanical strength,
There was a problem that it was difficult to make it thin. Therefore,
Although it has been proposed to use a plastic film having excellent strength as a base material, in this case, high heat of about 250 to 300 ° C or more is applied to the base film from the heating head during printing, and the base plastic is A phenomenon in which a part of the film is fused to the head occurs and the feeding of the thermal transfer recording film ribbon is hindered. This phenomenon is called sticking, and in addition to the loss of recording clarity, problems such as poor running of the thermal transfer recording film ribbon have occurred. Therefore,
As a method for making a plastic film usable as a base film for heat-sensitive transfer recording, it has been proposed to provide a heat-resistant protective layer such as a thermosetting resin on the surface of the film.

(Problems to be solved by the invention) However, if these methods are used and the heat-resistant protective layer is thickened in order to prevent sticking phenomenon and speed up recording, the resolution of printing is deteriorated. Not a solution.

In addition, if you try to improve the heat transfer by making the base material thinner to increase the recording speed, the stiffness of the 4 film ribbon for thermal transfer becomes weak and wrinkles and bends occur, causing the ribbon to move. Feeding may be poor and may cause operational problems.

Thus, when trying to increase the output speed of a computer, it has been pointed out that there is no suitable thermal transfer recording material, and a thin base film with excellent heat resistance and strength is required. There is.

An object of the present invention is to provide a base film for heat-sensitive transfer recording, which can solve the sticking phenomenon at the time of heat-sensitive transfer in response to the above-mentioned requirements, and can meet the problems such as high-speed recording and clearing of print / image. Especially.

(Means for Solving the Problems) As a result of intensive studies to achieve the above-mentioned object, the present inventors have found that a biaxially oriented thermoplastic polymer having a specific F-5 value, a heat shrinkage ratio, and a film thickness. The inventors have found that an etherketone resin film has excellent properties as a base film, and have reached the present invention.

That is, the present invention is such that the sum of the F-5 value in the length direction and the F-5 value in the width direction of the film is 24 kg / mm ² or more, the heat shrinkage ratio at 150 ° C. is 2.0% or less, and the thickness is 0.8 to 6.0 μm and an average particle size of 0.05 to 4 μm as a lubricant in the film
of the biaxially oriented thermoplastic polyetherketone resin film containing 0.01 to 3.0% by weight of spherical silica fine particles of m or 0.005 to 3.0% by weight of silicone resin fine particles having an average particle diameter of 0.01 to 4 μm. It is a material film.

Thermoplastic polyetherketone resin in the present invention,
Constituent units Or Is a polymer consisting of the above unit alone or another constituent unit. As other constituent units, for example, And the like. In the above structural unit, A is a direct bond, oxygen, —SO ₂ —, —CO— or a divalent lower aliphatic hydrocarbon group, and Q and Q ′ may be the same or different. - or -SO _2, n is 0 or 1. These polymers are described in JP-B-60-32642, JP-B-61-10486, JP-A-57-137116 and the like.

Thermoplastic polyetherketone resins may be blended with resins such as polyarylene polyether, polysulfone, polyarylate, polyester, polycarbonate, etc. for the purpose of improving fluidity, etc., and stabilizers, antioxidants, ultraviolet absorbers And the like.

As described above, the thermoplastic polyetherketone resin is known per se, and can be produced by a method known per se.

The thermoplastic polyetherketone resin has an apparent melt viscosity of 380 ° C. and an apparent shear rate of 1000 sec ⁻¹ ,
Those in the range of 500 poises to 1000 poises, more preferably 1000 poises to 5000 poises are preferable from the viewpoint of film-forming property and film property.

The polyetherketone resin film used in the present invention is biaxially oriented, and the sum of the F-5 value in the length direction and the F-5 value in the width direction is 24 kg / mm ² or more, preferably
It must be 26 kg / mm ² or more. If the sum of the F-5 values is less than 24 kg / mm ² , especially less than 22 kg / mm ² , there is a problem that the film during running may be bent or wrinkled.

F-5 value in the length direction of the base film and F-5 in the width direction
The sum of the values needs to be 24 kg / mm ² or more, but with oriented film that is too uniaxially biased, there is a high possibility that the film will stretch or tear during use. The five values are preferably at least 10 kg / mm ² or more.

The sum of the F-5 value in the length direction and the F-5 value in the width direction is 24 kg / m.
The thermoplastic polyetherketone resin film of the present invention having m ² or more has, for example, a melting point (Tm: ° C.) + 30 ° C. to (Tm
The thermoplastic polyetherketone resin is melt extruded at a temperature of +90) ° C. to obtain an unstretched film, and the unstretched film is uniaxially (longitudinal or transverse) (Tg−10) to (Tg + 45) ° C.
At a temperature (however, Tg: glass transition temperature of the polyetherketone resin) of 2.5 times or more, and then in the direction perpendicular to the above-mentioned stretching direction (when the first stage stretching is the longitudinal direction, the second stage stretching is the transverse direction). At a temperature of (Tg + 10) ~ (Tg + 40) ° C
It can be produced by stretching at a draw ratio of 2.5 to 5.0 times. In this case, the area draw ratio is preferably 6 times or more. The stretching means may be either simultaneous biaxial stretching or sequential biaxial stretching.

Further, the polyetherketone resin film used in the present invention needs to have a heat shrinkage ratio at 150 ° C. of 2.0% or less, preferably 1.5% or less. Heat shrinkage is 2
%, Particularly 3%, the film is heat-contracted when it comes into contact with the heating head, and wrinkles are formed on the tape to deteriorate the slipperiness, which is not preferable. In order to reduce the heat shrinkage at 150 ° C to 2.0% or less, the film that has been subjected to the above-mentioned biaxial stretching (Tg
It may be heat-set at a temperature of +70) ° C to Tm ° C. For example,
200-3 for polyetheretherketone film
It is preferable to heat-set at 50 ° C. The heat setting time is, for example, 1 to 120 seconds.

Further, the polyetherketone resin film used in the present invention has a thickness of 0.8 to 6.0 μm, preferably 1.0.
~ 3.0 μm. When the thickness of the base film is less than 0.8 μm, the F-5 value in the length direction and the width direction is 24 kg / mm ²
Even if it is more than the above, since the strength (stiffness) is lowered, operating problems such as bending and wrinkling occur when the film is run as a thermal transfer recording film.

On the other hand, when the thickness exceeds 6 μm, heat transfer is hindered, and thus a heating time is required to be long and the speed of thermal transfer recording is reduced. Further, when the substrate film becomes thick, the heating area by the heating head and the area of the colored layer that is heated and melted by transfer become difficult to match, so-called bleeding occurs, the sharpness of recording is impaired, and the resolution is lowered, which is preferable. Absent.

The heat-sensitive transfer recording substrate film of the present invention may have a heat-resistant protective film formed on the surface opposite to the side provided with the colored layer.

In addition, the base film for heat-sensitive transfer recording is usually added with inert solid particles in order to obtain an appropriate surface roughness, but when the stretching ratio is increased to increase the F-5 value, it is included. Due to the coarse particles and the agglomerated particles, the problem that the film is frequently cut may occur. However, the spherical silica fine particles having an average particle diameter of 0.05 to 4 μm and a particle diameter ratio (major axis / minor axis) of 1.0 to 1.2 have a content of 0.
When it is dispersed or contained in the thermoplastic polyetherketone resin alone or in a mixture with other inert solid particles so as to be 01 to 3.0% by weight, or the average particle diameter is 0.01 to 4 μ.
m, f = V / D ³ (where V is the average volume of the particles (μm ³ ),
D represents the average maximum particle size (μm) of the particles) and has a volumetric shape factor (f) of 0.4 to π / 6.
_{2-X / 2} (where R is a hydrocarbon group having 1 to 7 carbon atoms, X
Is 1 to 1.2), and the fine particles of silicone resin represented by the formula (1) to (1.2) are dispersed alone or in a mixture with other inert solid particles so as to have a content of 0.005 to 3.0% by weight and dispersed in a thermoplastic polyetherketone resin. In this case, since the spherical silica fine particles, the silicone resin fine particles and the polyetherketone resin have a high affinity, voids are less likely to occur around the particles when the biaxial orientation is performed, and the film is not cut. It is particularly preferable because the film can have good running properties.

In this case, it is preferable that the spherical silica fine particles are substantially spherical, have a sharp particle size distribution and are nearly monodisperse, and the manufacturing method thereof is not limited to the above. In particular, it is desirable that the relative standard deviation represented by the following equation be 0.5 or less.

For example, spherical silica particles can be prepared from ethyl orthosilicate Si
Hydrolysis of (OC ₂ H ₅ ) ₄ produces hydrous silica Si (OH) ₄ monodisperse spheres, and the hydrous silica monodisperse spheres are dehydrated to give a three-dimensional silica bond ≡Si-O-Si≡. It can be manufactured by growing it (Journal of the Chemical Society of Japan '81, No9, P.150
3).

Si (OC ₂ H ₅ ) ₄ + 4H ₂ O → Si (OH) ₄ + 4C ₂ H ₅ OH ≡Si-OH + HO-Si≡ → ≡Si-O-Si≡ + H ₂ O On the other hand, the silicone resin particles are substantially It is preferably spherical and has a sharp particle size distribution and is close to monodisperse, and is not limited to the production method or the like. In particular, it is desirable that the viscosity distribution ratio (γ) represented by the following formula is 1 to 1.4.

γ = D ₂₅ / D ₇₅ The spherical silicone resin fine particles are represented by the following formula (A) R × SiO ₂ −x / _{2 2} (A) It has a composition represented by

R in the above formula (A) is a hydrocarbon group having 1 to 7 carbon atoms, and for example, an alkyl group having 1 to 7 carbon atoms, a phenyl group or a tolyl group is preferable. The alkyl group having 1 to 7 carbon atoms may be linear or branched, for example, methyl, ethyl, n-propyl, iso-propyl, n-
Butyl, iso-butyl, tert-butyl, n-pentyl,
n-heptyl and the like.

Among them, R is preferably methyl and phenyl, and particularly preferably methyl.

X in the above formula (A) is a number of 1 to 1.2. When x is 1 in the above formula (A), the above formula (A) is
The following formula (A) -1 RSiO _1.5 (A) -1 (where R has the same definition as above) can be used.

The composition of the above formula (A) -1 has the following structural portion in the three-dimensional polymer chain structure of the silicone resin; It is derived from.

When x is 1.2 in the above formula (A), the above formula (A) is represented by the following formula (A) -2 R _1.2 SiO _1.4 ... (A) -2 [where R has the same definition as above. Is given by:

The composition of the above formula (A) -2 has a structure of the above (A) -1 of 0.1.
It can be understood that it is composed of 8 mol and 0.2 mol of a structure represented by the following formula (A) ′ R ₂ SiO ... (A) ′ [where R is defined as above].

The above formula (A) 'represents the following structural portion in the three-dimensional polymer chain of the silicone resin; Derived from

As understood from the above description, the composition of the above formula (A) substantially consists of, for example, only the above formula (A) -1 structure, or the structure of the above formula (A) -1 and the above formula (A) A)
It can be seen that the structure of -2 consists of a structure coexisting in a state of being randomly bonded at an appropriate ratio.

The spherical silicone resin particles preferably have a value of x between 1 and 1.1 in the above formula (A).

The silicone resin particles have, for example, the following formula: RSi (OR ′) ₃ The trialkoxysilane represented by or a partial hydrolyzed condensate thereof can be produced by hydrolyzing and condensing in the presence of ammonia or an amine such as methylamine, dimethylamine, ethylenediamine and the like with stirring. According to the above method using the above starting material, the silicone resin particles having the composition represented by the above formula (A) -1 can be produced.

R ₂ Si (OR ′) ₂ According to the above method, the dialkoxysilane represented by the formula (A) is used together with the above trialkoxysilane.
Silicone resin particles having the composition represented by -2 can be produced.

Thus, when the particle size distribution is close to monodisperse and contains fine particles that do not aggregate, there is almost no film breakage during stretching, and the dielectric breakdown voltage can be maintained at a high level, with particularly good results. can get.

As the heat-sensitive transferable colored layer that can be provided in the heat-sensitive transfer recording substrate film of the present invention, a conventionally known heat-sensitive transferable colored layer can be used as it is and is not particularly limited.

The heat-sensitive transferable colored layer is a composition containing a colorant and a binder. A dye or pigment is used as the colorant. Inorganic pigments such as carbon black, organic pigments,
Examples thereof include azo dyes and anthraquinone dyes. Carnaup wax as a binder,
Examples thereof include waxes such as wood wax, beeswax, and ester wax, and compositions such as a polymer typified by ethyl cellulose to which a recording accelerator such as dinitrotoluene is added, and various compositions that can be transferred by being softened when heated. Things can be used. In addition, a plasticizer, a softening agent such as oil, and other additives for improving weather resistance may be included. The thickness of these heat-transferable colored layers is usually 0.5.
μm to 20 μm, preferably 0.8 μm to 10 μm, and more preferably 1 μm to 5 μm. These colored layers can be formed by hot-melt coating on a base film, or by dispersing or melting the composition in a solvent and applying the coating solution.

In the present invention, the effect of the present invention can be sufficiently exhibited even when the heat resistant protective film is not provided on the other surface of the base film, or a heat resistant protective film is further provided on one surface of the base film. May be. Examples of the heat resistant protective film include silicone resin, epoxy resin, melamine resin, phenol resin, fluororesin, polyimide resin, nitrocellulose, acrylic resin, polyester resin, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate, fluorine. Vinylidene chloride resin, chlorinated rubber, cyclized rubber, polyvinyl alcohol, boron nitride,
Silica, talc, guanamine resin, paraffin wax, amides or salts of higher fatty acids, etc. are used, and these can also be used in combination. Also,
There is also a method of providing a metal layer by vapor deposition of aluminum or the like, but the method is not particularly limited. The heat-resistant protective film preferably has a thickness of 0.05 to 10 μm, and a thickness of 0.01 to 5 μm.
The range of m is more preferable, and the range of 0.05 to 3 μm is particularly preferable. If the thickness is thin, the stick preventing effect becomes insufficient, and if it is thick, it becomes difficult to increase the printing speed.

Various physical properties and characteristics in the present invention are measured by the methods described below.

(1) Cut the F-5 value film into a sample width of 10 mm and a length of 15 cm, and place it between the chucks.
It was pulled to 100 mm with an Instron type universal tensile tester at a pulling speed of 10 mm / min and a chart speed of 500 mm / min.
The stress at 5% elongation of the obtained load-elongation curve was calculated.

(2) Heat shrinkage rate The heat shrinkage rate was calculated by marking the film with a contact point of 30 cm, placing it in a hot air circulation type oven kept at 150 ° C for 30 minutes, and reading the dimensional change.

(3) Film surface roughness CLA (Center Line Average) JIS
It was measured according to B 0601. Using a stylus type surface roughness meter (SURFCOM3B) manufactured by Tokyo Seimitsu Co., Ltd., the radius of the needle is 2μ.
The chart (film surface roughness curve) was drawn under the conditions of m and load of 0.07 g. From the film surface roughness curve, a portion of the measurement length L is extracted in the direction of the center line, the center line of the extracted portion is taken as the X axis, and the longitudinal magnification direction is taken as the Y axis.
When represented by the roughness curve Y = f (X), the value (Ra: μm) given by the following equation is defined as the flatness of the film surface.

In the present invention, 8 pieces were measured with a reference length of 0.25 mm, and Ra was expressed as an average value of 5 pieces excluding 3 pieces with the largest value.

(4) Average particle size (DP) Shimadzu CP-50 type Centrifugal Particle Size Analyzer (Centrifugal Particle Size)
Analyser). From the integrated curve of particles of each particle size calculated based on the obtained centrifugal sedimentation curve and the abundance thereof, the particle size corresponding to 50 mass% was read, and this value was taken as the above average particle size ("particle size measurement Technology "), published by Nikkan Kogyo Shimbun, 1975, see pages 242-247).

5) Slipperyness in the printer The feeding condition such as whether or not the ribbon slips on the ribbon feeding roller of the thermal printer and whether or not wrinkles are formed is checked.

×: Ribbon slips and conveyance is defective.

△: Ribbons may have wrinkles and slip slightly, but there is no conveyance failure and it can be used practically.

○ …… Slightly wrinkled on the ribbon, but it did not slip, and there was no conveyance failure.

◎ …… Good feed condition.

(6) Image Quality The lightness and bleeding of the image printed / printed on the thermal printer were examined.

×: The image has light and shade, and also has a strong bleeding and is not practical.

△: Practical is acceptable although there is a slight difference in shade and there is bleeding.

○: Slight bleeding is seen, but there is no shading and it is good.

◎ …… Very good without light and shade.

(Example) Hereinafter, an Example is shown and this invention is further demonstrated.

Examples 1 to 8, Comparative Examples 1 to 8 Thermoplastic polyether ether ketone (ICI: polyether ether ketone 380G) having an average particle size of 0.8 μm,
0.2 wt% of spherical silica particles with a particle size ratio of 1.1 was added and blended, then extruded at 380 ° C by an extruder and cast on a casting drum kept at a temperature of 80 ° C to prepare an unstretched film, which was produced at 160 ° C. Was stretched in the longitudinal direction at the stretching ratio shown in Table 1, further fed to a tenter, stretched in the transverse direction at the stretching ratio shown in Table 1, and heat-set at the temperature shown in Table 1. The Ra of the film is 0.021 μm, and other characteristics are shown in Table 1. This biaxially oriented film is used as a base film, and 30 parts by weight of carnaup wax, 35 parts by weight of paraffin wax, and oil black HB are provided on the upper surface of the film.
A mixture of 5 parts by weight of B (oil-soluble dye manufactured by Orient Chemical Industry Co., Ltd.), 25 parts by weight of carbon black and 5 parts by weight of lanolin was heat-melted and hot-melt coated to a thickness of 4 μm to prepare a film for thermal transfer recording. Obtained.

Table 2 shows the evaluation results obtained by slitting this heat-sensitive transfer recording film into a width of 8 mm and using it as a heat-sensitive transfer ribbon and applying it to a thermal printer.

As is clear from the above results, the thermal transfer recording substrate film of the present invention (Examples 1 to 8) has good slidability and image quality in a printer of the film, but Outside the range (Comparative Examples 1 to 8), film wrinkles are contained and the slipperiness is poor, and the image quality is also poor, and satisfactory results cannot be obtained.

(Effects of the Invention) According to the present invention, it is possible to provide a base film for heat-sensitive transfer recording which eliminates the stick phenomenon during heat-sensitive transfer and can sufficiently withstand high-speed printing.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihiro Nomi 3-37-19 Oyama, Sagamihara City, Kanagawa Prefecture, Teijin Ltd. Plastics Research Laboratory (56) References JP 62-95289 (JP, A) JP SHO 59-152894 (JP, A) JP 62-193889 (JP, A) JP 63-237989 (JP, A) JP 1-186380 (JP, A)

Claims (1)

(57) [Claims] 1. The sum of the F-5 value in the length direction and the F-5 value in the width direction of the film is 24 kg / mm ² or more, the heat shrinkage rate at 150 ° C. is 2.0% or less, and the thickness is 0.8 to 6.0. 0.01 to 3.0% by weight of spherical silica fine particles having an average particle size of 0.05 to 4 μm as a lubricant in the film or an average particle size of 0.01 to 4 μm.
A base film for thermal transfer recording comprising a biaxially oriented thermoplastic polyetherketone resin film containing 0.005 to 3.0% by weight of silicone resin fine particles of m.