JPS58136820A - Preparation of fibrous high polymeric crystal - Google Patents

Abstract

PURPOSE:To grow a fibrous high polymeric crystal at a higher rate, by inserting a seed crystal in a flowing solution of a high polymer, and bringing the flowing solution into contact with the surface of a rotor set at a lower temperature than the flowing solution of the high polymer. CONSTITUTION:A solution 13 of a crystalline high polymer is made to flow through a gap between a rotor 10 and a closed container 9 of a Couette flow type crystallization vessel, etc., and a seed crystal is inserted from a pipe 11 and brought into contact with the surface of the rotor 10. The resultant fibrous crystal 12 growing from the contact part is then taken off from the pipe 11 at almost the same speed as the growth rate. A refrigerant or heating medium at a constant temperature is then passed through the rotor 10 to set the surface temperature of the rotor 10 lower than that of the solution 13. A fibrous polyethylene crystal obtained from a polyethylene solution exhibits mechanical properties, e.g. >=10g/denier strength, >=200g/denier Young's modulus and <=20% elongation at break.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention produces fibers with high strength and high elastic modulus by inserting a seed crystal into a fluid solution of a crystalline polymer and pulling out the fibrous polymer/crystal that grows from the tip of the seed crystal. I was inspired by a method to continuously produce shaped polymer crystals.

Fibrous polyethylene crystals are formed when a polyethylene seed crystal is inserted into a polyethylene/xylene solution flowing according to Boiseuille's law.
Co11o by Urg and A. J. Pennings
idand Polymer Sc+,, 2
5 vol. 3, pp. 452-461, 1075
reported in the year.

This technique is based on Chokrakshi's method of growing single crystals of metals and inorganic materials (Z, I'hys, Chem, 02
vol., p. 219, 1918), but the fact that fibrous polymer crystals can be produced from a fluid solution of a crystalline polymer presents a new method for fiber manufacturing technology. The fibrous polymer crystals obtained in this way exhibit excellent mechanical properties without being stretched4-, but in order to utilize this method industrially, the growth rate in the direction of the fiber axis must be slow. Therefore, research is being carried out to increase this growth rate, and Japanese Patent Publication No. 55-20004 discloses a Cuenoto-type crystallization method consisting of a rotor arranged to move, a closed container, and a force). Use a container and store l in the container.
At! 11 solution is used to form seed crystals on the rotor surface, and the contact length between the fibrous crystals that grow therefrom and the rotor is specified to be at least 15 cm,
This allows practical growth speed and mechanical 4! It is said that t t'l can be obtained. Furthermore, to increase the growth rate by 1:, the [I-tar surface was sandblasted.
< Or, coat the surface of the glass 1'j-tar with methyl chloride.
One person has made it non-polar by treating it with I l''I silane.

The purpose of the present invention is to grow fibrous crystals at a higher rate in the method described at the beginning of this specification. Then, a seed crystal is inserted into the fluidized solution and brought into contact with the surface of the first target, and fibrous polymer crystals are grown from the contact area in the direction of flow/J°, and the growth rate is controlled. In a method for continuously producing fibrous polymer crystals by drawing off the seed crystal at a speed approximately equal to , the rotor temperature is lower than the temperature of the fluid solution (
This is a manufacturing method characterized by setting.

In one embodiment of the present invention, a Couette-type crystallization vessel shown in FIG. 1 is used, and a refrigerant or heat medium fluid at a constant temperature is passed through the rotor to cool the surface of the rotor. The effect on the growth rate of large fiber crystals was investigated by lowering the temperature. As a result, if the rotor material, surface roughness, and other conditions (solution concentration, temperature, flow rate) are the same, the temperature of the rotor is lower than the temperature of the flowing solution (it is better to reduce the fibrous growth on the rotor surface). It was known that the growth rate of crystals was considerably high.
There is no need to set the contact length between the fibrous crystal and the rotor to 1° or more than 15c1 as specified in Publication No. 5-20004.
It was found that practical growth rates and mechanical properties could be obtained.

Since it is difficult to directly measure the temperature of the rotor surface, the rotor surface temperature was adjusted by the temperature and flow rate of the refrigerant or heat transfer fluid supplied into the rotor. It was found that the lower the temperature of the refrigerant or heating fluid supplied to the tank, the higher the growth rate of fiber crystals1. Although water or silicone oil can be used as long as it is compatible with the above conditions, silicone oil was used in this experiment.

More precisely, this experiment suggested that there is an appropriate temperature range for manufacturing based on the temperature difference between the rotor surface and the flowing solution, but it depends on the shape and size of the crystallization vessel used. Moreover, the container in the present invention is not limited to a Couette type crystallization container, so it cannot be specified. However, if the shape and size of the crystallization container used is fixed,
It is easy to find suitable cooling conditions for the movable surface during production so that the temperature of the movable surface on which the Ta-fold crystal grows is lower than the temperature of the fluid solution.

Note that it is preferable that the moving surface of Ill is not completely smooth, and the growth rate is higher if it is moderately rough.

The pulling speed of fibrous crystals growing from a solution must be approximately equal to the growth rate in order to keep the position of the tip approximately constant, and is easily determined depending on other conditions (solution concentration, temperature, flow rate) It can be changed within a predetermined range. As the withdrawal speed increases, the fibrous crystal becomes thinner, and the limit on the withdrawal speed is determined by whether it cuts or moves its tip through the movable surface. On the other hand, when the drawing speed is lowered to 1.5, the fibrous crystal becomes thicker, and the lower limit of the drawing speed is determined by the fact that the tip moves and the length of the fibrous crystal on the movable surface increases. Therefore, in order to collect fibrous crystals of a certain thickness (denier) by fixing the concentration, temperature and flow rate of the solution, it is necessary to use a movable surface! It is sufficient to keep the length of the fibrous crystals in contact with - approximately constant, and when cooling the movable surface, the length is not limited to 15c- or more.

The thickness (denier) of the fibrous crystals is determined by the concentration, temperature, flow rate, and withdrawal speed of the solution. The higher the concentration, the thicker (
There is a relationship that the lower the temperature, the thicker the fiber, and the higher the flow velocity determined by the speed of the movable surface, the thicker the fiber becomes.By these parameters, the drawing speed that is approximately equal to the growth speed in the flow direction of one large crystal of the thickening fiber is determined as described above. By setting within a predetermined range, the thickness (denier) of the fibrous crystal can be adjusted.

(7) However, the mechanical properties of the fibrous crystals obtained in this way tend to decrease as the thickness (denier) increases, so it is necessary to take this into consideration when setting manufacturing conditions. . However, since the influence of the factors that determine the thickness (solution concentration, !S degree, flow rate, and take-up speed) on mechanical properties is not uniform, even if the thickness and denier are the same, the mechanical There are different characteristics that need to be stocked.

The fibrous polymer crystals of the present invention can be produced using a Couette-type crystallization vessel schematically illustrated in FIG. but,
Other devices can also be used in the method of the invention. Any device can be used within the scope of the present invention as long as it can cool the movable surface on which fibrous crystals grow and set the temperature of the movable surface to be lower than the temperature of the fluid solution. When the movable surface is the surface of the rotor, the rotation axis of the p-tor can also be set in the horizontal direction. In this way, the fibrous crystals can be taken out only from the upper part, and there is an advantage that many fibrous crystals can not be taken out from the surface of one rotor.

When the method of the present invention is applied to polyethylene, examples of solvents include xylene, decalin, balasoy/wax, hydrocarbons, terpenes, naphthalene, etc., and xylene solutions have a 0. (2) to 1.0% concentration is preferred. The preferred range of solution concentration also depends on the molecular weight of the polyethylene, the solution temperature, and the properties of the solvent.

When the method of the present invention is applied to polyethylene, the seed crystal is not limited to the fibrous polyethylene grown under special crystallization conditions described in the examples of Japanese Patent Publication No. 55-2'OO04, Any fibrous material that is insoluble in the polyethylene solution may be used, such as cotton thread, hemp thread, or wool. When using the former type of fibrous polyethylene as a seed crystal, it is more convenient to use the latter type of fibrous material since it may dissolve in the fluid solution in this method depending on the crystallization conditions.

The fibrous crystals obtained by this JJ method have a high mechanical strength.
'l ll is known to be small. For example, fibrous polyethylene crystals obtained from a polyethylene solution have a strength of 10 g/d or more, a Young's modulus of 200 g/d or more, and a 1-1 elongation at break of 20% or less.

In the following examples, the crystalline polymers are limited to polyamide and 1° tyrene, but the present invention is not limited to these, and all crystalline polymers to which the method of the present invention can be applied. It encompasses molecules.

Example 1 High-density polyethylene (!-) 1 petrochemical grade high-grade 7xφ millio/) with an average molecular weight of 2,000,000 was dissolved in p-1 and silane to prepare a 0.5% solution. , an oxidizing agent (di-tert-butyl-valacresol) in the solution 0
Experiments were carried out by adding 5% to stabilize the solution. A reprinted wool yarn (number 40, single yarn) was used as a seed crystal.

The device d used was created according to the Couette type crystallization vessel described in Japanese Patent Publication No. 55-20004, except that the temperature of the rotor in the inner cylinder can be changed by a refrigerant or a heating fluid. are different. A schematic diagram of the apparatus is shown in FIG. 1, and an internal sectional view of the rotor is shown in FIG. 2. The outer diameter of the rotor is 121 mm, and the inner diameter of the container is 133 mm.

The wool thread used as the seed crystal was inserted through the tube 11 and brought into contact with the rotor surface, and the fibrous crystals growing from the contact portion were taken from the tube 11 and wound up into a winding machine provided separately. The crystallization vessel was immersed in a silicone oil bath to maintain a constant temperature within a range of about 0.05°C.

An experiment was conducted as follows to clarify the temperature effect on the rotor surface, which is a feature of the method of the present invention. Growth of fibrous crystals when the rotor surface is cooled by flowing silicone oil at a constant temperature into the rotor, and when the rotor surface temperature is kept in equilibrium with the temperature of the fluid solution without flowing silicone oil into the rotor. Compare the speeds.

Smooth Teflon was used as the rotor material, and the flow rate of silicone oil was always maintained at 11/min. In addition, the take-up speed is approximately 12 cm in length of the fibrous crystal in contact with the movable surface.
: I tried to keep it at ■. 1st & 2nd ih LOt
At a temperature of 106°C, the number of rotations of the rotor is 4Or, 11,
I, the growth rate of fibrous crystals was not affected by rotor cooling. Table 2 shows 1 at a solution temperature of 117°C.
Figure 2 shows the effect of cooling the rotor on the growth rate of fibrous crystals when the rotational speed of the rotor is 25 r, p, m. From this result, it is known that the growth rate increases considerably when the temperature of the rotor surface is cooled. The mechanical properties of the fiber crystals thus obtained were as follows: strength 33 g/d, Young's modulus 731 g/d1, elongation at break 6, depending on the crystallization conditions.
% was achieved. The stress-elongation curve is shown in FIG.

Table 1 Effect of rotor cooling on growth rate (solution temperature If
toe ℃, rotor rotation speed 40r, p, m) Table 2 Effect of cooling of noter on growth rate (temperature 7℃, rotor rotation speed 25r, p, m, in the case of)

[Brief Description of the Drawings] Fig. 1 is a schematic diagram of a crystallization vessel used in an example of the present invention, Fig. 2 is a sectional view of a rotor in the apparatus of Fig. 1, and Fig. 3 is a schematic diagram of a crystallization vessel used in an example of the present invention. Figure 1 shows the stress-elongation curve of crystalline polyethylene. 1. Fluid population for refrigerant or heating medium 2 Fluid outlet for refrigerant or heating medium 3, Rotor cylinder 4, Shaft 5, Fluid 11j port for refrigerant or heating medium 6, Refrigerant or heating medium lower part, [''-Tally seal Apparatus & shaft 9, container cylinder 10, rotor 11, tube 12 - tlA fibrous viscous crystal, p-xylene solution of polyethylene Patent applicant: Toyobo Co., Ltd. Figure 1, page 2, 3GLE 7) - Parallel long rib extension υ゛(%) [Continued Sode Ichi *<h formula) % formula% 1. Table of events 1982 Patent Application No. 19263 2. Name of the invention Fibrous ^ Molecular Crystal Creativity Method 3. Make amendments Relationship with the case of the Patent applicant: No. 2, No. 8, Dojimahama IL, Kita-ku, Osaka City, May 7, 1982 (Delivery date: May 25, 1980) 5. Figure 3 of the first page of Title I of the amended No. 6. Contents of the amendment First, replace the drawing with attached sheet Figure 3, which deletes the simple explanatory text of the drawing.

Claims (1)

[Claims] 1. A solution of a crystalline polymer is made to flow between a notar and a closed container disposed so as to be movable with respect to each other, and then a seed crystal is inserted into the fluid solution. In a method for continuously producing fibrous polymer crystals by bringing them into contact with a surface and growing fibrous crystals in the flow direction from the contact portion, and taking off the seed crystals at a rate approximately equal to the growth rate. , the above method is characterized in that the temperature of the rotor is set lower than the temperature of the fluid solution. 2. The crystalline polymer is polyethylene, the seed crystal is
The Jj method according to claim 1, item (G), characterized in that the fibrous material is insoluble in the τ-lyethylene solution.