JPS6256906B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyethylene terephthalate film with improved transparency and slipperiness. More specifically, the present invention relates to a polyethylene terephthalate film that maintains surface smoothness, has sufficient transparency, and has excellent slipperiness and adhesiveness. Polyethylene terephthalate film is used for a variety of purposes including photography, magnetic tape, packaging materials, electrical insulation materials, and the like. In these applications, base films used for metallized films, photographic films, microfilms, etc. are required to be transparent. At the same time, these applications require not only transparency but also slipperiness, which greatly affects film formation and processability. However, although methods such as adding a small amount of inorganic fine powder etc. to polyethylene terephthalate film to give it slipperiness have been studied, it has not been possible to overcome the problem of loss of transparency as a result. Ta. The present inventor has focused on these problems and, as a result of intensive research, has discovered that by mixing specific additives with polyethylene terephthalate, a novel film having both transparency and slipperiness can be obtained. That is, the present invention comprises 100 parts by weight of a polyester resin component (A) consisting of polyethylene terephthalate or a mixture of polyethylene terephthalate and polybutylene terephthalate, and a neutral or partially neutralized montan wax salt or montan wax ester salt (B). )0.01～
It is a polyethylene terephthalate film consisting of 2 parts by weight. Polyethylene terephthalate, component (A) in the present invention, can be obtained by polycondensing a terephthalic acid component and an ethylene glycol component. In this case, isophthalic acid, phthalic acid,
Dicarboxylic acids other than terephthalic acid such as 2,6-naphthalene dicarboxylic acid, glycols other than ethylene glycol such as diethylene glycol, 1,4-butanediol, neopentyl glycol, hydroxycarboxylic acids such as p-hydroxybenzoic acid, dimethylolpropionic acid, etc. A small amount of acid etc. can also be used together. The terephthalic acid component is used as a free acid, a derivative such as dialkyl ester or diphenyl ester, and the ethylene glycol component is used as a free derivative such as glycol, diacetate or ethylene oxide. In the polycondensation, esterification or polymerization catalysts such as calcium acetate, zinc acetate, p-toluenesulfonic acid, alkyl titanates, and antimony trioxide can be used. Polycondensation is carried out by distilling off water, alcohol, etc. under normal pressure or high vacuum.
The process is continued until a predetermined degree of polymerization is reached. The intrinsic viscosity of the obtained polyethylene terephthalate (measured at 35 °C in orthochlorophenol solution) is 0.45-1.0
It is preferable that Component (A) in the present invention includes a mixture of polyethylene terephthalate and polybutylene terephthalate. Preferably, the proportion of polybutylene terephthalate in the mixture is 60% by weight or less. Polybutylene terephthalate can be obtained by polycondensing a terephthalic acid component and a 1,4-butanediol component. in this case,
Dicarboxylic acids other than terephthalic acid, such as isophthalic acid, phthalic acid, and 2,6-naphthalene dicarboxylic acid; or glycols other than 1,4-butanediol, such as ethylene glycol, diethylene glycol, neopentyl glycol, and 1,6-hexanediol; Furthermore, a small amount of hydroxycarboxylic acids such as p-hydroxybenzoic acid and dimethylolpropionic acid can also be used in combination. For example, if terephthalic acid is used as the acid component, 1,4-butanediol 80
Examples include polyesters whose glycol components include mol% and 20 mol% of ethylene glycol. Terephthalic acid components include free acid, dialkyl ester,
Derivatives such as diphenyl ester, and 1.4
-Butanediol component is used as a derivative such as free glycol or diacetate. The catalyst and polymerization method are the same as for polyethylene terephthalate. Intrinsic viscosity of the obtained polybutylene terephthalate (measured at 35°C in orthochlorophenol solution)
is preferably in the range of 0.45 to 1.3. The neutral or partially neutralized montan wax salt or montan wax ester salt, which is component (B) of the present invention, refers to an acid mixture of aliphatic monocarboxylic acids mainly having 26 to 32 carbon atoms (hereinafter referred to as It is a metal salt produced using montanic acid (called montanic acid) as a raw material. Suitable montanwax salts contain as cations metals from main groups of the periodic table, such as lithium,
Contains at least one of sodium, potassium, barium, magnesium, calcium, aluminum, etc. Particularly preferred is the sodium salt of montanic acid. Neutral or partially neutralized montan wax salts are prepared by the reaction of the above aliphatic monocarboxylic acid mixtures with 0.2 to 1.0 equivalents of the above metal hydroxides or metal oxides, in particular with a caustic soda solution. Montanic acid sodium salt produced by the reaction is effective. Montan wax ester salt is produced by partially esterifying montanic acid with up to 0.90 equivalents, especially 0.5 to 0.8 equivalents, of a dihydric alcohol having 2 to 4 carbon atoms in the alkylene group, and then esterifying montanic acid with an oxide of the above-mentioned metal. Alternatively, it can be obtained by neutralizing with hydroxide. Examples of the dihydric alcohol used for esterification include ethylene glycol, 1,2- or 1,3-propanediol, 1,3- or 1,4-butanediol, and the like. The amount of component (B) is 0.01 to 2 parts by weight per 100 parts by weight of the polyester resin (A). If the amount is less than 0.01 part by weight, the slipperiness of the film is insufficient.
If the amount is more than 2 parts by weight, the hue of the film will be poor. When producing the film of the present invention, the (A) and (B) components are dry blended and then put into an extruder to form an extrusion film.The (A) and (B) components are kneaded in advance in an extruder. A method can be arbitrarily selected in which a chip is made and the chip is used to form a film by extrusion. In the present invention, trace amounts of known additives such as fine inorganic powders, colorants, stabilizers, and lubricants may be used together with components (A) and (B) within a range that does not impair the effects of the invention. The film of the present invention may be an unstretched film, a uniaxially stretched film, a biaxially stretched film, etc., and is preferably a sequentially biaxially stretched film. For example 3.2-5.5 in the longitudinal direction at a temperature of 70-120℃
A biaxially stretched film is obtained by stretching the film twice and then stretching it in the transverse direction by 3 to 4.8 times. By further heat-setting the film at 190 to 240°C for several seconds to several tens of seconds, a film with good dimensional stability can be obtained. The obtained film had excellent transparency and slipperiness. Hereinafter, the present invention will be specifically explained with reference to Examples. Examples 1 to 5, Comparative Example 1-2 Polyethylene terephthalate with an intrinsic viscosity of 0.69
After drying at 160°C, a predetermined amount of powdered sodium salt of montanic acid (melting point: 178°C) was added and mixed.
The mixture was melt-extruded at 280°C and rapidly solidified on a casting drum kept at 40°C to a thickness of 164 μm.
An unstretched film with a thickness of . Next, it was stretched at 80℃ with a magnification of 3.6, and further stretched at 110℃ with a magnification of 3.6.
After transversely stretching the film to an angle of 3.8, it was heat-set at 210°C for 5 seconds to obtain a biaxially stretched film. The properties of the film are shown in Table 1.

[Table] In Examples 1 to 5, films with excellent transparency and slipperiness were obtained. Haze and friction coefficient were measured by the methods described below. (1) Haze (cloudiness) According to JIS-K6714, the haze of the film was determined using an integrating sphere HTR meter manufactured by Nippon Seimitsu Kogaku Co., Ltd. (2) Coefficient of Friction The coefficient of static friction and the coefficient of dynamic friction were determined with a load of 200 g and a slide speed of 15 cm/mm using a TKK type friction coefficient measuring device manufactured by Tester Sangyo. During the measurements, the samples were left at a temperature of 20° C. and a humidity of 65% for one day and night, and then measurements were conducted under the same conditions. The coefficient of dynamic friction was measured 1 minute after sliding. μ=f/p μ=coefficient of friction f=frictional force p=speed applied to the film Examples 6 to 9 Chips of polyethylene terephthalate with an intrinsic viscosity of 0.65 and chips of polybutylene terephthalate with an intrinsic viscosity of 1.08 are mixed at a predetermined ratio, After drying at 160°C, the sodium salt of montanic acid (melting point 178
A predetermined amount of powder (°C) was added and mixed. mixture
The mixture was melt-extruded at 280°C and rapidly solidified on a casting drum kept at 40°C to obtain an unstretched film with a thickness of 125 μm. Then magnification at 80℃
Table 2 shows the properties of a biaxially stretched film obtained by longitudinally stretching at a ratio of 3.2, further transversely stretching at 108°C at a ratio of 3.2, and then heat-setting at 200°C for 5 seconds.

[Table] In Examples 6 to 9, films with excellent transparency and slipperiness were obtained. Example 10 A film was prepared in exactly the same manner as in Example 1, except that in place of the sodium salt of montanic acid, a predetermined amount of montanate partially neutralized with 0.75 equivalents of sodium hydroxide was used. The properties of the obtained film are shown in Table 3. Example 11 In place of the sodium salt of montanic acid in Example 1, partially esterified sodium montanate (montanic acid was esterified with 0.75 equivalents of 1,4-butanediol and then neutralized with sodium hydroxide). A film was prepared in exactly the same manner as in Example 1, except that a predetermined amount of the following was used. The properties of the obtained film are shown in Table 3.

[Table] In Examples 10 to 11, films with excellent transparency and slipperiness were obtained. Examples 12-13 In Example 1, sodium salt of montanic acid was used instead of sodium salt of montanic acid and the average particle size was 0.85.
Table 4 shows the properties of the film obtained in the same manner as in Example 1 except that a predetermined amount of μ kaolin was added and mixed.

[Table] In Examples 12 and 13, films with excellent transparency and slipperiness were obtained.

Claims (1)

[Claims] 1. Polyester resin component (A) consisting of polyethylene terephthalate or a mixture of polyethylene terephthalate and polybutylene terephthalate (A) 100
Part by weight and neutral or partially neutralized montan wax salt or montan wax ester salt (B) 0.01~
A transparent, easily slippery polyethylene terephthalate film consisting of 2 parts by weight. 2. The polyethylene terephthalate film according to claim 1, wherein component (A) is polyethylene terephthalate and component (B) is sodium salt of montanic acid.