JP4874611B2 - Method for producing stretched thermoplastic polyester resin sheet - Google Patents

Description

  The present invention relates to a method for producing a stretched thermoplastic polyester resin sheet, and more particularly to a method for producing a stretched thermoplastic polyester resin sheet having excellent tensile strength, tensile elastic modulus, and heat resistance.

Conventionally, a method for producing a transparent crystalline polymer sheet having a smooth surface and a high strength and elastic modulus by pultrusion has been studied. For example, crystals such as polyethylene, polypropylene, polyacetal resin, nylon, etc. The temperature of the base sheet of the differential polymer calorimetry melting curve is not exceeded the deformation starting temperature when the sheet is heated at a rate of temperature increase of 1 ° C./min with a 10 MPa load applied to the sheet. There has been proposed a method for producing a crystalline polymer sheet, which is drawn through at least a draw ratio of 2.5 times or more through a pair of heated rollers (see, for example, Patent Document 1).
JP 60-15120 A

  However, in order to stretch a polyester resin by the above method for producing a crystalline polymer sheet, the polyester resin is too hard at low temperatures and lacks flexibility necessary for stretching, and relaxation of orientation becomes dominant at high temperatures. Therefore, in order to obtain a stretched sheet having excellent strength and elastic modulus, it is necessary to perform pultrusion molding within the temperature range of the glass transition temperature of the polyester resin -20 ° C to the glass transition temperature + 20 ° C. The system resin sheet has a drawback in that the elastic modulus rapidly decreases when heated to a temperature higher than the glass transition temperature.

  In addition, when a polyester resin sheet is pultruded, the stretched polyester resin sheet that has been pultruded varies in the stretching ratio in the width direction of the polyester resin sheet, resulting in meandering. For this reason, the pultruded stretched polyester resin sheet could not be continuously uniaxially stretched.

  An object of the present invention is to provide a method for producing a stretched thermoplastic polyester resin sheet excellent in tensile strength, tensile elastic modulus and heat resistance by uniaxially stretching after pultruding a polyester resin sheet in view of the above drawbacks. It is to provide.

In the method for producing a stretched thermoplastic polyester resin sheet according to claim 1 of the present invention, the thermoplastic polyester resin sheet in an amorphous state is pulled with a drive roll, and the glass transition temperature of the thermoplastic polyester resin is -20 ° C to After drawing a pair of drawing rolls having a glass transition temperature of + 20 ° C. of the thermoplastic polyester resin and producing a drawn stretched thermoplastic polyester resin sheet, a pair of drawn stretched thermoplastic polyester resin sheets are continuously formed. In the method for producing a stretched thermoplastic polyester resin sheet, the stretched thermoplastic polyester resin sheet is uniaxially stretched at a temperature higher than the temperature of the drawing roll, and the stretched thermoplastic polyester resin sheet is further heat-set at a temperature higher than the uniaxial stretch temperature. Pulling stretched thermoplastic polyester by pressing inclined rolls on stretched thermoplastic polyester resin sheet After removal of the slack of the ether-based resin sheet, wherein the uniaxially stretched.

The method for producing a stretched thermoplastic polyester resin sheet according to claim 2 , wherein the uniaxial stretching temperature is the rising temperature of the crystallization peak of the thermoplastic polyester resin on the differential operation calorimetric curve measured at a heating rate of 1 ° C / min. The rising temperature of the melting peak is the method for producing a stretched thermoplastic polyester resin sheet according to claim 1 , which can be preferably uniaxially stretched.

The method for producing a stretched thermoplastic polyester resin sheet according to claim 3 , wherein the heat setting temperature is a melting peak of the thermoplastic polyester resin in a differential operation calorimetric curve measured from a uniaxial stretching temperature to a heating rate of 1 ° C / min. 3. The method for producing a stretched thermoplastic polyester resin sheet according to claim 1 or 2 , wherein the heat setting can be stably and reliably performed.

The method for producing a stretched thermoplastic polyester resin sheet according to claim 4 is characterized in that the heat setting is performed in a state in which the stretched thermoplastic polyester resin sheet stretched uniaxially is fixed so as not to shrink due to heat. Item 2. A method for producing a stretched thermoplastic polyester resin sheet according to item 1, 2, or 3 , wherein heat setting can be performed more stably and reliably.

  Examples of the thermoplastic polyester resin used in the present invention include polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyglycolic acid, poly (L-lactic acid), poly (3-hydroxybutyrate), poly ( 3-hydroxybutyrate / hydroxyvalerate), poly (ε-caprolactone), polyethylene succinate, polybutylene succinate, polybutylene succinate adipate, polybutylene succinate / lactic acid, polybutylene succinate / carbonate, polybutylene succinate Nate / terephthalate, polybutylene adipate / terephthalate, polytetramethylenadipate / terephthalate, polybutylene succinate / adipate / terephthalate, etc. Polyethylene terephthalate is preferable.

  Although the thickness of a thermoplastic polyester-type resin sheet is not specifically limited, 0.5-4 mm is preferable. If it is less than 0.5 mm, the thickness of the sheet after stretching becomes too thin, and the strength during handling may not be sufficient, and if it exceeds 4 mm, stretching may be difficult.

In the present invention, the amorphous thermoplastic polyester resin sheet in the amorphous state is pulled with a driving roll, and is drawn and drawn through a pair of drawing rolls. The glass transition temperature of the stretched thermoplastic polyester resin is -20 ° C to The drawn thermoplastic polyester resin is drawn and drawn through a pair of drawing rolls having a glass transition temperature of + 20 ° C.

When the temperature of the pair of drawing rolls during drawing and drawing is low, the drawn thermoplastic polyester resin sheet is too hard to be drawn, and when the temperature is high, the thermoplastic polyester resin sheet becomes soft and pulls out the sheet. Since the sheet is cut by tension, the glass transition temperature of the stretched thermoplastic polyester resin is -20 ° C to the glass transition temperature of the stretched thermoplastic polyester resin + 20 ° C , preferably the stretched thermoplastic polyester. The glass transition temperature of the resin-based resin to the glass transition temperature of the stretched thermoplastic polyester-based resin + 10 ° C.

  Further, when pulling out the amorphous polyester resin sheet in an amorphous state, the pair of pulling rolls need not rotate, but may be slightly rotated in the pulling direction in order to make the temperature distribution uniform.

  The draw ratio of the above-described drawing stretching is not particularly limited. However, if the stretching ratio is low, a sheet excellent in tensile strength and tensile elastic modulus cannot be obtained. If the stretching ratio is high, the sheet tends to break during stretching. 2-9 times is preferable, More preferably, it is 4-8 times.

  In order to improve the physical properties such as tensile strength, tensile elastic modulus, heat resistance, etc., the thermoplastic polyester resin sheet drawn and stretched in the present invention is uniaxially stretched at a temperature higher than the temperature of the drawing roll. The thermoplastic polyester resin sheet has slack (meander) because the stretch ratio is not constant and the length is not uniform due to a partial defect of the thermoplastic polyester resin sheet which is the raw material. .

  Therefore, in the present invention, before the uniaxial stretching, the slanting (meandering) of the drawn stretched thermoplastic polyester resin sheet is removed by pressing the inclined roll against the drawn stretched thermoplastic polyester resin sheet.

  Specifically, the slanting (meandering) of the drawn stretched thermoplastic polyester resin sheet is performed by pressing the inclined roll against the drawn stretched thermoplastic polyester resin sheet that has been drawn and stretched between the drawn roll and the drive roll. Remove.

  The inclined roll is a roll that is mechanically held so as to be movable in the advancing direction, the upward direction, etc. of the drawn stretched thermoplastic polyester resin sheet in which the shafts at both ends of the roll are drawn and stretched, and the drawn stretched thermoplastic polyester According to the state of slack (meandering) of the resin-based resin sheet, the sheet is moved in the advancing direction, the upward direction, etc., and the sheet is pressed to stretch the stretch-drawn thermoplastic polyester resin sheet where there is slack (meandering). Remove.

  When this inclined roll is used, a position measuring device for the drawn and stretched thermoplastic polyester resin sheet is installed in front of the inclined roll, and the slack (sheet position deviation) is measured by the position measuring device. It is preferable to control the position (pressed state) of the inclined roll.

  Also, examples of different inclined rolls are rolls in which the shafts at both ends of the roll are independently urged by springs or the like in the direction of advance or upward of the drawn stretched thermoplastic polyester resin sheet. The portion of the drawn stretched thermoplastic polyester resin sheet with (meandering) is pressed and stretched to remove sagging (meandering).

The polyester resin of the drawn thermoplastic polyester resin sheet that has been drawn and drawn is tensile because molecular chains are highly oriented with isotropic crystallization and orientation suppressed by heat, which is a hindrance to stretching. Although the strength and tensile modulus are excellent, the degree of crystallinity is low, so that when heated, the orientation is easily relaxed and the tensile modulus decreases.

  However, the stretched thermoplastic polyester resin sheet that has been drawn and stretched is uniaxially stretched at a temperature higher than that of the roll, so that the degree of crystallinity is increased without relaxation and the orientation is easy even when heated. Thus, a stretched sheet having excellent heat resistance that is not relaxed can be obtained.

  As the uniaxial stretching method, a roll stretching method is preferably used. The roll stretching method is a method in which a stretched raw fabric is sandwiched between two pairs of rolls having different speeds, and the stretched raw fabric is pulled while being heated, and the molecular orientation can be strongly oriented only in a uniaxial direction. In this case, the speed ratio of the two pairs of rolls becomes the draw ratio.

  The temperature at the time of the uniaxial stretching may be higher than the temperature of the pair of rolls at the time of drawing and drawing, but if it is too high, the drawn and stretched thermoplastic polyester resin sheet is melted and cut. The temperature range from the rising temperature of the crystallization peak of the thermoplastic polyester resin to the rising temperature of the melting peak in the differential operation calorie curve measured at a heating rate of 1 ° C./min is preferable.

  The rising temperature of the crystallization peak of polyethylene terephthalate is about 120 ° C., and the rising temperature of the melting peak is about 230 ° C. Accordingly, when the polyethylene terephthalate sheet is uniaxially stretched, it is preferably uniaxially stretched at about 120 to about 230 ° C.

  The stretching ratio of the uniaxial stretching is not particularly limited, but if the stretching ratio is low, a sheet excellent in tensile strength and tensile elastic modulus cannot be obtained. If the stretching ratio is high, the sheet tends to break during stretching. 1.1-3 times are preferable, More preferably, it is 1.2-2 times. Moreover, the total draw ratio of primary stretching and uniaxial stretching is preferably 2.5 to 10 times for the same reason.

Furthermore, in order to improve the heat resistance of the uniaxially stretched stretched thermoplastic polyester resin sheet, it is heat-set.

  If the heat setting temperature is lower than the uniaxial stretching temperature, the crystallization of the thermoplastic polyester resin does not proceed, so the heat resistance is not improved, and the thermoplastic polyester system in the differential operation calorimetric curve measured at a heating rate of 1 ° C./min. If the temperature rises above the rise temperature of the melting peak of the resin, the thermoplastic polyester-based resin dissolves and the stretching (orientation) disappears, and the tensile modulus, tensile strength, etc. decrease, so the uniaxial stretching temperature to the heating rate of 1 ° C./min. The rising temperature of the melting peak of the thermoplastic polyester resin in the measured differential operation calorimetric curve is preferred.

  In addition, when heat-fixed, the stretched thermoplastic polyester resin sheet is stretched if a load is applied, and contracts in a free state. Therefore, the stretched thermoplastic polyester resin sheet is not loaded but is shrunk by heat. It is preferable to carry out in the state fixed so that it may not carry out, and it is preferable that the stretched thermoplastic polyester-type resin sheet is not pressurized. For example, it is preferable to heat-set in a state where both ends of the stretched thermoplastic polyester resin sheet are held with a pinch roll or the like so as not to be loaded. Therefore, heating is preferably performed with hot air, a heater, or the like.

  The time for heat setting is not particularly limited, and is generally 10 seconds to 5 minutes, although it varies depending on the thickness of the stretched thermoplastic polyester resin sheet and the heat setting temperature.

  The stretched thermoplastic polyester resin sheet produced by the method for producing a stretched thermoplastic polyester resin sheet of the present invention is excellent in tensile strength, tensile elastic modulus, and heat resistance. Preferably used.

  The stretched thermoplastic polyester resin sheet may be used by being laminated, or other unstretched thermoplastic polyester resin sheet, stretched polyolefin resin sheet, polyolefin resin, vinyl chloride resin, You may laminate | stack with thermoplastic resin sheets, such as ABS resin, AES resin, AS resin, and acrylate resin.

  The structure of the method for producing the stretched thermoplastic polyester resin sheet of the present invention is as described above, and the drawn stretched thermoplastic polyester resin sheet is supplied to the uniaxial stretching step and uniaxially stretched without sagging (meandering). The drawn stretched thermoplastic polyester resin sheet is uniaxially stretched without meandering, and a stretched thermoplastic polyester resin sheet excellent in tensile strength, tensile elastic modulus, and heat resistance can be obtained efficiently. Moreover, the stretched thermoplastic polyester resin sheet heat-fixed after uniaxial stretching is further excellent in heat resistance.

  Next, examples of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following examples.

  FIG. 1 is an explanatory view showing an example of a method for producing a stretched thermoplastic polyester resin sheet of the present invention, and FIG. 2 is a plan view showing a state of a drawn stretched thermoplastic polyester resin sheet.

  In the figure, 1 is a supply roll for a thermoplastic polyester resin sheet, 3 is a brake roll, 4 is a preheating device, 5 is a drawing roll, and 8 is a drive roll.

  The thermoplastic polyester resin sheet 2 wound around the supply roll 1 is pulled by the drive roll 8 while being braked by the brake roll 3, heated to a predetermined temperature by the preheating device 4, and then the predetermined temperature is reached. The pair of drawing rolls 5 that have been set is drawn out to obtain a drawn stretched thermoplastic polyester resin sheet 6.

  An inclined roll 7 is installed between the drawing roll 5 and the driving roll 8, and a position measuring device 9 is installed on information between the drawing roll 5 and the inclined roll 7. The inclined roll 7 is installed below the drawing-drawn thermoplastic polyester resin sheet 6 in FIG. 1, and the shafts at both ends of the roll are independently moved in the direction of travel of the drawing-drawn thermoplastic polyester resin sheet 6 (right direction in the figure). ) Is held freely. Further, the shafts at both ends of the position measuring device 9 and the inclined roll 7 are independently connected to a control device (not shown), and the deflection (displacement) of the drawn stretched thermoplastic polyester resin sheet 6 is positioned. The tilting roll 7 is moved by the data measured by the measuring device 9 and the deflection of the drawing stretched thermoplastic polyester resin sheet 6 pressed by the tilting roll 7 is removed.

  That is, the pultruded drawn stretched thermoplastic polyester resin sheet 6 is bent as shown by a broken line in FIG. 2 due to variations in crystallinity of the thermoplastic polyester resin sheet, variations in heating temperature, etc. (Slip) occurs, and the drawn stretched thermoplastic polyester resin sheet 6 is pressed in the advancing direction by the inclined roll 7 to remove sagging (slack), and the drawn stretched thermoplastic polyester resin sheet as shown by the solid line. The traveling direction of 6 is controlled to be parallel to the traveling direction.

  In the figure, reference numeral 10 denotes a heating furnace for uniaxial stretching, and a plurality of stretching rolls 11 are installed in the heating furnace 10. A cooling roll 12, a driving roll 13, and a winder 15 are installed on the outlet side of the heating furnace 10.

  The drawn stretched thermoplastic polyester resin sheet 6 from which slack has been removed is supplied to a heating furnace 10 and heated and stretched by stretching rolls 11, 11. The stretched thermoplastic polyester resin sheet 14 that has been stretched is pulled by the drive roll 13, discharged from the outlet of the heating furnace 10, cooled by the cooling roll 12, and wound by the winder 15.

Example 1
A polyethylene terephthalate sheet (trade name “A-PET sheet FR” manufactured by Teijin Chemicals Ltd.) 2 having a thickness of 2 mm and a width of 200 mm is supplied to the stretching device, preheated to 75 ° C. by the preheating device 4, and then heated to 80 ° C. The pair of heated drawing rolls (roll interval 0.2 mm) is drawn and drawn by setting the speed of the driving roll 8 to 2 m / min, and then the surface temperature of the polyethylene terephthalate sheet is set to 170 in the heating furnace 10. The film was heated to ° C., and the speed of the driving roll 13 was set to 2.5 m / min and roll-stretched to obtain a stretched polyethylene terephthalate sheet having a stretch ratio of 5 times (± 0.2 times).

  At this time, when the drawn and stretched polyethylene terephthalate sheet 6 was stretched with tension by the inclined roll 7, the meandering level was stable within ± 5 mm.

  The polyethylene terephthalate sheet has a glass transition temperature of 72 ° C., a rising temperature of a crystallization peak in a differential operating calorimetry curve measured at a heating rate of 1 ° C./min, about 118 ° C., and a rising temperature of a melting peak is about It was 230 ° C.

(Comparative Example 1)
When a stretched polyethylene terephthalate sheet was obtained in the same manner as in Example 1 except that the inclined roll 7 was not used, the drawn stretched polyethylene terephthalate sheet 6 meandered 50 mm or more, and stretching was difficult.

It is explanatory drawing which shows an example of the manufacturing method of the extending | stretching thermoplastic polyester-type resin sheet of this invention. It is a top view which shows the state of a drawing extending | stretching thermoplastic polyester-type resin sheet.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Supply roll of thermoplastic polyester-type resin sheet 2 Thermoplastic polyester-type resin sheet 3 Brake roll 4 Preheating apparatus 5 Drawing roll 6 Drawing drawing thermoplastic polyester-type resin sheet 7 Inclination roll 8 Drive roll 9 Heating furnace 10 Position measuring apparatus 11 Stretch roll 12 Cooling roll 13 Drive roll 14 Stretched thermoplastic polyester resin sheet 15 Winder

Claims (4)

A thermoplastic polyester resin sheet in an amorphous state is pulled with a driving roll, and between a pair of drawing rolls having a glass transition temperature of −20 ° C. to a glass transition temperature of the thermoplastic polyester resin + 20 ° C. After drawing a drawn stretch thermoplastic polyester resin sheet, the drawn stretch thermoplastic polyester resin sheet is continuously uniaxially stretched at a temperature higher than the temperature of the pair of draw rolls , and further uniaxially stretched. In a method for producing a stretched thermoplastic polyester resin sheet in which a thermoplastic polyester resin sheet is heat-set at a temperature higher than a uniaxial stretching temperature, a stretched thermoplastic polyester system is formed by pressing an inclined roll against the stretched thermoplastic polyester resin sheet. Stretching characterized by uniaxial stretching after removing slack in the resin sheet Method for producing a thermoplastic polyester resin sheet. Uniaxial stretching temperature, according to claim 1, characterized in that a rising temperature of the rising temperature-melting peak of the crystallization peak of the thermoplastic polyester resin in the differential scanning calorimetry curve measured at a heating rate 1 ° C. / min Method for producing a stretched thermoplastic polyester resin sheet. Heat setting temperature is, according to claim 1 or 2, characterized in that the rising temperature of the melting peak of the thermoplastic polyester resin in the differential scanning calorimetry curve measured by uniaxial stretching temperature - heating rate 1 ° C. / min A method for producing a stretched thermoplastic polyester resin sheet. 4. The production of a stretched thermoplastic polyester resin sheet according to claim 1, 2 or 3 , wherein the heat setting is performed in a state where the stretched thermoplastic polyester resin sheet stretched uniaxially is not shrunk by heat. Method.

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