JPS5949938B2 - polyethylene terephthalate film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an outdoor spreading material made of polyethylene terephthalate film.

More specifically, the present invention aims to provide an outdoor spreading material made of an oriented film that has excellent weather resistance and dust resistance and can withstand long-term outdoor spreading. In general, polyethylene terephthalate film is known to exhibit high crystallinity, high melting point, and have excellent properties such as heat resistance, chemical resistance, strength, and elastic modulus. It is widely used for industrial purposes, photography, metallization, packaging, and agriculture.

However, this film does not have excellent weather resistance, and has the drawback that its mechanical properties deteriorate significantly when exposed outdoors for a long time. In order to improve the weather resistance of the film, it is known to add ultraviolet absorbers or to coat the film surface, but this does not provide enough weather resistance to withstand long-term outdoor exposure. As a result of intensive research on a polyethylene terephthalate film that does not have such defects, the present inventor found that the refractive index in the vertical and horizontal directions is 1.57 or more, the refractive index in the thickness direction is 1.57 or less, and the density is 1.57 or more. 39
0 g/d or less, and the antimony content of the film is 0.
An oriented polyethylene terephthalate film that can maintain the elongation at break in at least one direction of the film at 10% or more even when irradiated for 100 hours with a high-pressure mercury lamp containing 01 to 0.07% by weight and having the strongest spectrum at 365 nm. , excellent transparency, and the high-pressure mercury lamp
It maintains a breaking strength of 50% or more of the breaking strength before irradiation even after hours of irradiation, exhibits extremely excellent weather resistance and dust resistance, and has extremely excellent resistance to heat deterioration. The present invention has been achieved based on the discovery that the method is suitable as a method.

That is, in the present invention, the refractive index of the film in the longitudinal and lateral directions is 1.57 or more,
Refractive index in thickness direction is 1.57 or less, density is 1.390f
l/Cwt or less, the elongation at break in at least one direction of the film is 10% even when irradiated for 100 hours with a high-pressure mercury lamp containing 0.01 to 0.07% by weight of antimony and having the strongest spectrum at 365 nm. It is an outdoor stretchable material made of oriented polyethylene terephthalate film that can hold more than

The polyethylene terephthalate referred to in the present invention includes not only a non-copolymerized polyethylene terephthalate homopolymer but also a polyethylene terephthalate homopolymer having a repeating unit of 85? Copolymerized polyethylene terephthalate in which the above consists of ethylene terephthalate units and the remainder is other components, or polyethylene terephthalate in an amount of 85% by weight or more (preferably 90% by weight?
(or more) and less than 15% by weight (preferably less than 10% by weight) of other polymers.

Examples of other polymers that can be blended include polyamides, polyolefins, and other types of polyesters. In addition, the polyethylene terephthalate may be used as a lubricant, if necessary.
It may contain a matting agent, a coloring agent, a stabilizer, an antioxidant, an antistatic agent, etc. The polyethylene terephthalate film used in the outdoor spreading material of the present invention is oriented and has a refractive index in the longitudinal and transverse directions of 1.57 or more, preferably 1.59 or more, particularly preferably 1.61 or more.

The refractive index of the film in the thickness direction is 1.57 or less, preferably 1.56 or less, particularly preferably 1.55 or less. The density of the film is 1.3909/d or less, preferably 1.3829/d or less, more preferably 1.3799/d or less.
/(71t or less. The means for orienting the film is not particularly limited, and may be uniaxial stretching or biaxial stretching. In the case of uniaxial stretching, if the direction perpendicular to the stretching direction is constrained and stretched, the film will be stretched in both the longitudinal and lateral directions. However, it is not necessarily necessary to restrict the film as long as a film satisfying the above conditions can be obtained. In the case of biaxial stretching, for example, sequential biaxial stretching in longitudinal and lateral directions (first longitudinal stretching, then transverse stretching, Or vice versa), any orientation method may be employed, such as simultaneous biaxial stretching in the longitudinal and lateral directions.The polyethylene terephthalate film used in the present invention contains 0.01 to 0.07 ?wt. Must.

Ankomon content is 0.01 weight? If the weight is less than 0.07, the initial light transmittance will be high, but the dust resistance will decrease, so it is not preferable. If the amount is more than 1, the hue of the polymer becomes dark, the initial light transmittance decreases, and the heat deterioration resistance also decreases, which is not preferable. A more preferable lower limit of the persimmon content is 0.02% by weight, and a more preferable upper limit is 0.06% by weight? It is. Antimony may be contained in the form of a metal or a compound, but it can be contained in a dissolved state in polyethylene terephthalate (such a state can occur in salts of antimony). Preferably, it is contained. Therefore, metal antisene and antimony trioxide can also be used, but salts of antimony with inorganic or organic acids, double salts of antimony (for example, antimony potassium tartrate, etc.),
Salts of antimonic acid (eg, potassium pyroantimonate, etc.) are preferably used. One particularly preferably used is an acetate obtained by reacting antimony trioxide with acetic acid. In addition, when an antimony compound is added, it goes without saying that the above-mentioned antemony content is a value for the antimony component of the added compound. Perilla may be added to the polymer after completion of polycondensation, but
It is preferably added to the polymer production raw material during or before polycondensation, also serving as a polycondensation catalyst. Therefore, for example, an antimony compound may be added to the raw material before transesterification together with a transesterification catalyst, or an antimony compound may be added to a melt of bis(β-hydroxyethyl) terephthalate. Further, the polyethylene terephthalate film used in the present invention has a breaking elongation of at least 10% in at least one direction even when irradiated for 100 hours with a high-pressure mercury lamp having the strongest spectrum at 365 nm. It is possible to hold more than that.

It is preferable that the elongation at break after the irradiation can be maintained at 15% or more, particularly 25% or more. In the film used in the present invention,
0.01 to 0.07 weight of antimony? Since the content contains excellent heat deterioration resistance and dust resistance, and the refractive index, density, and elongation at break after irradiation with the high-pressure mercury lamp meet the above requirements, it is possible to break in at least one direction after irradiation with the high-pressure mercury lamp for 100 hours. The intensity is 50% of the intensity before irradiation with the lamp
In combination with the above, and the elongation at break of 10% or more, it is possible to exhibit excellent weather resistance.

The polyethylene terephthalate film used in the outdoor expansion material of the present invention can be used at, for example, a normal extrusion temperature (260 to 3
A polyethylene terephthalate-terminated stretched film with [η] (measured at 35°C using 0-chlorophenol as a solvent) of 0.4 to 1.0 was melt-extruded at 30°C) and was uniaxially stretched. The refractive index NSD in the direction perpendicular to the stretching direction (for example, the transverse direction after longitudinal stretching) is 1.
Stretching is performed at a stretching ratio of 2.5 to 5.0 times, preferably 3.0 to 4.5 times, so that the stretching temperature is 560 or less. is the temperature at which the NSD after uniaxial stretching is 1.560.

In addition, the lower limit of the stretching temperature is the lower limit of the low-temperature stretching temperature (i.e., the lower limit that does not cause extremely large thickness unevenness such as the mixture of unstretched parts and high-stretched parts that occur when the stretching temperature is too low). temperature). The stretching degree at which the NSD is 1.560 varies slightly depending on the type of polymer and the stretching ratio, but it is usually about 5 to 10° C. higher than the low-temperature stretching limit temperature. ], then, at 50 to 80°C, a stretching ratio of 2.5 to 5.0 is applied in a direction perpendicular to the stretching direction (if the stretching is in the longitudinal direction, then in the transverse direction).
Stretched by 3.0 to 4.5 times, preferably 3.0 to 4.5 times, and further stretched to 15 times
It can be obtained by heat setting at 0°C or lower for about 1 to 100 seconds. However, the film of the present invention can be
1. 'It goes without saying that it is not limited only to the obtained film. The polyethylene terephthalate film used in the outdoor spreading material of the present invention may have an appropriate thickness depending on its use.

Generally, a film having a diameter of 1μ to 2000μ is useful.The polyethylene terephthalate film used for the outdoor spreading material of the present invention itself has extremely excellent weather resistance, but it may be further added with an ultraviolet inhibitor or coated on the surface. 2. Even better weather resistance can be achieved.

In addition, if necessary, we can apply drop-free treatment to the film surface.
Post-processing such as lamination with other films may be performed. 3. The outdoor spreading material of the present invention can be exposed to sunlight, wind, rain, etc. for a long time (for example, about 10 months or more).
above) use.

It also has extremely excellent heat resistance, and the film does not deteriorate much even when exposed to high temperatures outdoors, such as when exposed outdoors while in contact with metal. In addition, it has excellent dust resistance, and will gradually increase when used outdoors.
3) There is less dirt, and when used as an agricultural film in greenhouses, for example, less cleaning of the film surface is required to restore the reduced light transmission. Therefore, it can be preferably used for outdoor applications such as greenhouses, other agricultural products, road signs, house exteriors, water irrigation equipment, blinds, piping, and other molded products that are exposed to the outside. The physical property measuring method used in the present invention is shown below.

1 Tensile test Using Tensilon UTM-1500 manufactured by Toyo Port Win Co., Ltd., at room temperature and relative humidity of 65%, the length was 10 CT.
n) An original film with a width of 1 (V!) was stretched at 100%/Mm to prepare a load-elongation chart, and each value was determined by calculation.

Elongation at break: The elongation relative to the original length at break is expressed in %. Breaking strength: The force required to break a film at room temperature is expressed as the force (K9/1) applied per unit cross-sectional area of the original film.

Digital color measurement color difference meter ND according to Hue JIS-P-8123
- Using an IOID type (manufactured by Nippon Denshoku Kogyo Co., Ltd.), the lightness L value; the a value representing red..., green H; and the b value representing yellow..., blue H were determined.

Refractive index The value for the D line of Na measured at 25° C. using an Atsube refractometer is shown.

Although the refractive index often changes in the width direction of the film, the value adopted in the present invention is the maximum value of the refractive index. The vertical direction (longitudinal direction) of the film is Nx, the horizontal direction (width direction) is Ny, and the thickness direction is Nz. 4 Density Value measured by milk sedimentation method in a mixed solvent of n-heptane and carbon tetrachloride at 25°C.

j Weather resistance test using a high-pressure mercury lamp (photochemical mercury lamp H4OO-P type manufactured by Tokyo Shibaura Electric Co., Ltd.) (using a 100V power supply)
A weather resistance test was conducted by placing a film in parallel at a distance of 20 cTn from a rod-shaped radiation source and irradiating the film surface for a predetermined period of time.The H400-P photochemical mercury lamp has the following operating characteristics. It is.

Total length: 295mm Tube diameter: 18.5mwL Lamp power: 400W Lamp voltage: 130V Lamp current: 3.3A Arc length: 150mm Brightness: 200cd/Cil Strongest spectrum: 365nm Radiation limit: 220nm 6 Heat deterioration resistant hot air circulation type The heat deterioration resistance of the sample is evaluated by the elongation at break and the strength at break of the sample which has undergone accelerated deterioration at 145° C. for 150 days in a constant temperature bath (gear aging tester).

7 In order to qualitatively express the amount of dust attached to the surface of the dustproof film, 4
The light transmittance of a sample exposed outdoors for a year and after washing the sample with ethanol was measured, and the measured values were expressed as comparative values.

8 Intrinsic viscosity of film [η] Value measured at 35°C using 0-chlorophenol as a solvent.

The unit is 100cC/f! It is. EXAMPLES Hereinafter, the present invention will be explained in detail with reference to examples, but these examples are not intended to limit the present invention in any way.

Examples 1 to 3 and Comparative Examples 1 to 3 100 parts of dimethyl terephthalate and 70 parts of ethylene glycol were melted in an oxygen-free nitrogen atmosphere, and the dimethyl terephthalate was mixed with manganese acetate at a temperature of 150°C. (Tetrahydrate salt) 0.05 parts, antimony trioxide 0.018 parts (Example 1), 0.036 parts (Example 2), 0.072 parts (Example 3), or 0.0 parts, respectively.
A solution of 90 parts (Comparative Example 1) dissolved in 1 part of ethylene glycol was added.

Next, a transesterification reaction was carried out at 220°C under atmospheric pressure for about 3 hours to distill methanol out. After the reaction was completed, 0.029 part of trimethyl phosphite was added to the product, and the temperature was raised as quickly as possible until the temperature of the product reached 285°C. Example 1), about 3 hours (Example 2), about 1 hour (Example 3)
, or for about 0.6 hours (Comparative Example 1), polyethylene terephthalate having an intrinsic viscosity of 0.65 was obtained, respectively. The antimony content of these polyethylene terephthalates is 0.015% by weight (
Example 1), 0.03% by weight (Example 2), 0.06% by weight (Example 3) or 0.075% by weight (Comparative Example 1). On the other hand, for comparison, 0.03
Transesterification and polycondensation were carried out in the same manner as in Example 2, except that 0.01 part of germanium dioxide was added instead of 6 parts, to obtain polyethylene terephthalate with an intrinsic viscosity of 0.65 (Comparative Example 2).

These polyethylene terephthalates were dried at 170°C, 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 1100μ.

The unstretched film was subjected to a longitudinal stretching temperature of 60°C, a longitudinal stretching ratio of 3.2 times, a transverse stretching temperature of 60°C, a transverse stretching ratio of 3,
Sequentially biaxially stretched at 5 times, and then heated to a predetermined heat setting temperature (see Table 1)
The film was heat-set for 10 seconds to form a biaxially oriented film with a thickness of 100 μm. In Comparative Example 3, an unstretched film was produced in the same manner as in Example 2 using the same polymer as in Example 2, and the unstretched film was subjected to longitudinal stretching at a longitudinal stretching temperature of 90°C and a longitudinal stretching ratio of 3.2.
The film was sequentially biaxially stretched at a transverse stretching temperature of 110° C. and a transverse stretching ratio of 3 and 5 times, and heat-set at a predetermined temperature (see Table 1) for 10 seconds to form a biaxially oriented film with a thickness of 100 μm.

The results obtained are shown in Table 1.

Claims (1)

[Claims] 1 The refractive index of the film in the vertical and horizontal directions is 1.57 or more, the refractive index in the thickness direction is 1.57 or less, and the density is 1.39.
0g/cm^2 or less, antimony 0.01-0.0
7% by weight and is capable of maintaining the elongation at break in at least one direction of the film at 10% or more even when irradiated with a high-pressure mercury lamp having the strongest spectrum at 365 nm for 100 hours. .