JPH02265730A - Molding of thermotropic liquid crystal polymer film - Google Patents

Abstract

PURPOSE:To make it possible to mold well a thermotropic liq. crystal polymer and to obtain a film without anisotropic properties in strength by using a T-die wherein one or both of lips of the T-die are movable lips in the width direction of a film and molding a resin while both or one of the movable lips is mowed at a specified relative speed. CONSTITUTION:A thermotropic polymer is molded by using a T-die film molding apparatus fitted with a T-die. The thermotropic liq. crystal polymer is melt- moldable and exhibits liq. crystal characteristics when it is melted and a copolyester obtd. by forming a copolymerized oligomer obtd. by reacting polyethylene terephthalate with hydroxybenzoic acid or acetoxybenzoic acid in the presence of an acylating agent and polymerizing it is especially pref. The T-die 1 has a structure wherein each lip is slide-movable in the width direction of a film pinching an extrusion slit. The relative speed of the movements of movable die lips 2 and 3 is controlled at a value of a speed index (S) of an equation or larger and 10-fold of the S value or smaller, pref. in the range of 3-10-fold.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for forming a T-die film by melt-extruding a thermal liquid crystal polymer through a T-die to form a film (sheet).

[Conventional technology]

In recent years, there has been an increasing demand for materials with excellent rigidity, heat resistance, and dimensional stability, whether fibers, films, or molded products. Although polyester has excellent rigidity and is widely recognized for its uses, it has not been suitable for applications that require higher heat resistance and dimensional stability. Recently, liquid crystal polyesters have been attracting attention, and the ones that have been attracting particular attention are J, P, S, P, C, and E.
d/II (/976), 20II3 and Special Publication 1984-
This was after W. and J. Jakun published a thermoliquid crystalline polymer composed of polyethylene terephthalate and acetoxybenzoic acid in the publication No./1O/&.

However, these polymers exhibit a high degree of orientation in the molten state, resulting in large anisotropy in mechanical properties;
When a film is formed, only a film with excessive molecular orientation in the longitudinal direction is obtained, and therefore the film tends to tear longitudinally, making it impossible to obtain a film that can be used for practical purposes.

Various methods have been proposed to solve this problem of molecular orientation in films. For example, there is a method of laminating films whose molecules are oriented in the axial direction so that their orientation directions intersect with each other to obtain a high-strength film that has no directionality in terms of strength.

[Problem to be solved by the invention]

However, in this method, because the film is bonded,
This method not only increases the thickness of the film, but also requires a layering process and a bonding process, and has drawbacks such as complicated operations.

[Means to solve the problem]

The inventors of the present invention have made extensive studies to solve the above-mentioned problems during film molding of thermoliquid crystal polymers, and as a result, they have used a T-die in which the die lip of the T-die can relatively move back and forth along the width direction of the film. They discovered that by performing T-die molding while reciprocating the lip at a specific speed, it was possible to obtain a film with excellent tensile strength that was oriented almost equally in the vertical and horizontal directions, and finally completed the present invention. Ta.

That is, the gist of the present invention is to use a T-die with a movable lip in which one or both of the lips of the T-die can spring move in the width direction of the film, when performing T-die molding of a thermal liquid crystal polymer. The present invention relates to a method for forming a thermal liquid crystal polymer film, characterized in that both or one of the lips is formed at a speed expressed by the following formula (1).

However, G: Width of linear slit (dragon) MFI: Melt flow index at molding temperature (9770 minutes) t: Film thickness (mS: Speed index (mm/min)) As a thermoliquid crystal polymer that can be used in the present invention may be any polymer as long as it can be melt-molded and exhibits liquid crystallinity when melted; for example, the following polyesters [I] to [■], i.e. ), SO2, co, an alkylene group, an alkylidene group, or none, and R1 to R8 represent a hydrogen atom, a hydrogen atom, or a hydrocarbon group).

~ C5 hydrocarbon group, halogen atom, alkoxy group or phenoxy group), S02, C○, alkylene group or alkylidene group or none, R1 to R8 represent a hydrogen atom, halogen atom or hydrocarbon group) consisting of

[■-Dicarboxylic acid unit represented by general formula J), OO -C-R1-C- (J
) (wherein, at least 60 mol% of R1 is /, terphenylene group r), po mol% or less Ct, q-C6 to C+a divalent aromatic hydrocarbon group other than phenylene group, 04 ~Coo divalent alicyclic hydrocarbon group or C1~
Indicates a C4o covalent aliphatic hydrocarbon group. However, the hydrogen atom of the benzene ring of the aromatic hydrocarbon group (including /, ll-phenylene group) may be substituted with a halogen atom, an alkyl group or an alkoxy group of CI-04) General formula (K) Glycol unit -0-R represented by
”-0-・・・・・・・・・・・・(K) (in the formula, R2
is a C1-C2o divalent aliphatic hydrocarbon group or C4-
C20 covalent alicyclic hydrocarbon group) and oxycarboxylic acid unit -O-R3-C- (L) ( In the formula, at least 60 mol % or more of R3 is a /, terphenylene group, and less than 0 mol % is a 06 to C8 covalent aromatic hydrocarbon group other than the /, I!-phenylene group. However, the hydrogen atom of the benzene ring of the aromatic hydrocarbon group (including /, #-phenylene group) is a halogen atom, 01-
(which may be substituted with a C4 alkyl group or alkoxy group), but a part of the oxycarboxylic acid unit (L) is bonded to a part of the glycol unit (K) through an ether bond to form the general formula (M). -O-R2-0-R3-C-・・・・・・・・・・・・
...(M) (wherein R2 and R3 are (K) and (
The content of the dicarboxylic acid unit (J) is 70 to 110 mol%, and the dicarboxylic acid unit (J) has the same meaning as R2 and R3 in the formula L). ) and oxycarboxylic acid unit (L) relative to the total amount of oxycarboxylic acid unit (L)
The ratio (L) / (J) + (L) of L) is 30~
gθ mol%, glycol unit (K) and oxycarboxylic acid unit)
Oxycarboxylic acid units relative to the total amount of (L) (
L) ratio (L) / (K) + (L) is 30~g
o mole%, the ratio of units (M) to K (K) (M) / (K) is o-go mole%, and /:l (weight ratio) of phenol and tetrachloroethane. A copolymerized polyester having a logarithmic viscosity ηinh measured at 3θ°C at a concentration of 0.!r777dl in a mixed solution of ζydl/jj or more.

Furthermore, in addition to the above, polyesters of the following [■ to [bean]], namely [■ Substantive structure -H1-CI, -B
Indicates r or -CH3, and Z is composed of Ω 0, (Kun Osha+0CH2CH20+ or (feather indicating death).

Y -H.

C1 or H3 ).

thing.

(In the formula, X is CI.

Br.

H3 ) consisting of thing.

Something that could happen.

of.

etc.

Among them Those shown in (I) to (V) The preferred button is used.

In the present invention, polyethylene terephthalate as a thermoliquid crystalline polymer and hydroxybenzoic acid or acetoxybenzoic acid are contacted and reacted in the presence of an acylating agent and optionally a catalyst to produce a copolymerized oligomer, and then Particularly preferred are copolyesters obtained by polymerization. The acylating agent is preferably acetic anhydride, and the amount used is preferably at least twice the /,J, of hydroxybenzoic acid.

As a method for producing the above-mentioned copolyester, for example, polyethylene terephthalate and hydroxybenzoic acid are placed in a reaction vessel together with an acylating agent, and
The reaction is carried out for at least 1 minute, preferably 1 to 3 hours to obtain a copolymerized oligomer, and then polymerized at 2'10 to 100°C to obtain a product.

Alternatively, polyethylene terephthalate and hydroxybenzoic acid are first reacted at 130 to 250°C for 30 minutes or more, preferably / to 3 hours to form a copolymerized oligomer, and then an acylating agent is added and reacted at 100 to 230°C for 30 minutes or more to form an acyl It is also possible to obtain a product by carrying out a reaction and then polymerizing at 2φ0 to 300°C.

At this time, a suitable catalyst can be used at each stage.

A tin compound (eg, stannous acetate) is effective in the step of producing the copolymerized oligomer, and a zinc compound (eg, zinc acetate) is effective in the final polymerization reaction. The amount of catalyst added is based on the produced polymer! r O~! ;000 ppm, preferably 200 The raw material supply ratio of ethylene terephthalate and hydroxybenzoic acid is polyethylene terephthalate 8
5-33 mol%, hydroxybenzoic acid 5-63
It is suitably used in the proportion of mol%.

Furthermore, as the T-die film forming apparatus used in the present invention, any type of normally used type can be used, but the forming die is different from a normal T-die in that the lip of the die is pressed and rescued. A T-die is used that can move along the width of the film.

An example of a die used in the present invention is shown in FIGS. 1 and 2.

In FIG. 1, the die l has a structure that allows each lip to slide in the width direction of the film across the extrusion slit.

In the present invention, a thermal liquid crystal polymer is molded under specific molding conditions using a T-die film molding apparatus equipped with the above-mentioned T-die.

At least one of the movable lip roller and 3 of the Tgui film forming device is in the width direction of the film (direction that intersects with the extrusion direction).
Since the film is reciprocated, the film extruded from the die slit will be oriented in the combined direction of the extrusion direction and the moving direction of the lip, resulting in a film with obliquely oriented molecules as a whole. The degree of molecular orientation of this film is appropriately selected and determined by adjusting the moving speed of the movable lip, the extrusion speed of the resin, the take-up speed, etc. In addition, when reciprocating both movable lips,
It is preferable to move the molecules in opposite directions to provide uniform molecular orientation.

Furthermore, in the device shown in Figure 1, the movable die lip 2 (3) is an endless belt, and in this case, the die lip can be run continuously without reciprocating as shown in Figure 1. can.

In the present invention, in order to produce a film with excellent tensile strength, the relative speed of the movement of the movable lip λ and 3 (if the movable lips λ and 3 are moved simultaneously in opposite directions, the sum of the moving speeds of both, When only one of them is moved, the moving speed) is equal to or greater than the value of the speed index (S) shown by the following formula (1), and is less than or equal to 70 times the S value, preferably 7.2 times the S value. It is adjusted within the range of 10 times to 10 times, more preferably 3 times to io times the S value.

Here, S: Speed index (mz/min) G: Width of linear slit (dragon) MFI: Melt flow index at molding temperature Cg/10 min) t: Film thickness (IIm).

The speed index (S) mentioned above is an important index for the molding operation conditions of the present invention, and the lip speed depends on the fluidity of the resin used (MFI), the film thickness (1), and the slit width (G) of the die used. This defines the required relative movement speed (II+/min).

When the moving speed specified above is smaller than the speed index (S), the strength of the obtained film is not much different from that of a conventional T-die molded product, and the effects of the present invention cannot be fully exhibited. In addition, if the moving speed is more than 70 times the speed index (S), the thermal liquid crystal molecules will be excessively oriented in the lateral direction, resulting in a decrease in physical properties and further causing problems in terms of the durability of the molding equipment. This is not desirable as it may cause

Further, the extrusion speed and withdrawal speed of the resin are set to the same speed as normally performed in T-die molding.

The molding temperature when performing T-die molding using the above thermal liquid crystal polymer is such that the melt flow index of the thermal liquid crystal polymer is 7.
0 fi// 0 minutes or less, preferably 0.0.2 to 20
i// 0 minutes, more preferably 0, -~/j-fl
// It is carried out at a temperature that is in the range of 0 minutes. If the melt flow index is larger than the above upper limit, the film formation stability will be poor, which is not preferable.

In the present invention, the melt flow index refers to the JISKA 6
1//θ min).

Furthermore, the thickness (1) of the formed film is -~
Preferably it is 300μ, preferably in the range from 5 to 200μ.

Examples / (1) Method for producing thermal liquid crystal polymer Polyethylene terephthalate oligomer = (η1nh = o
, //dl/9) tq, 2 kg (10 mol) and p-hydroxybenzoic acid &, t, 2 kg were charged in a combined tank,
After purging with nitrogen three times, the polymerization vessel was heated to 110 °C,
The mixture was stirred for 7 hours, then stirred at i'yo°C for 7 hours while distilling acetic acid out, and further stirred at sqo°C for 7 hours. Furthermore, the temperature of the polymerization tank was raised to 275°C, and the pressure was gradually reduced while distilling acetic acid, and after 30 minutes, the pressure was reduced to 0. /! ; mt Hg. Next, the polymerization system was returned to normal pressure with N2, and zinc acetate dihydrate was added.
After adding g'g, the mixture was stirred for 6 hours in a vacuum of o,/grprxHg to complete polymerization, and the mixture was taken out from the polymerization tank and pelletized using a pelletizer.

(2) Film production method for thermo-liquid crystal polymer The thermo-liquid crystal polymer produced above was heated to Delcer 6 manufactured by Modern Machinery ■.
Slit width (die lip gap) for Sz type extruder
0. Using a T-die molding machine equipped with a T-die (T-die having the shape shown in Fig. 1) that can move the die lips in opposite directions through the die slit, the molding temperature is l×g°C. S θ μ
A T-Guy molded film was produced. The obtained film was evaluated by the following measuring method. The results are shown in Table 1.

Tensile strength: Cut the film into a strip, pull it at θOmx/min using a tensile tester, and read the strength when the film is cut.

JISZ/70 codraft ratio (DR): ρm: Specific volume when melted ρf: Specific volume of film G: Die gap t: Film thickness Examples 2 to 3 In Example/, the moving speed of the lip was adjusted to the conditions shown in Table/ The same procedure was carried out except for the following changes. Table 1 shows the results.
Shown below.

Comparative Example 1-λ The same procedure as in Example 1 was carried out except that the moving speed was changed to the conditions shown in Table 1.

The results are shown in Table 1.

〔Effect of the invention〕

According to the method of the present invention, thermoliquid crystalline polymers, which have been difficult to mold, can be successfully molded, and a film with no directionality in terms of strength can be obtained.

FIG.

7 in the figure is Gui, ko and 3 are die Li it Shown below.

Claims (1)

[Claims] (1) When T-die molding a thermal liquid crystal polymer, one or both of the lips of the T-die is a movable lip that can move in the width direction of the film, and both or one of the movable lips are molded as follows. Speed index (S
) A method for forming a thermoliquid crystal polymer film, characterized in that the film is formed while moving at a relative speed of at least 10 times the speed index (S) and at most 10 times the speed index (S). S=(π×30×G×MFI^0^.^2)/t...
・・・・・・(1) However, G: Width of linear slit (mm) MFI: Melt flow index at molding temperature (
g/10 min) t: Film thickness (mm) S: Speed index (mm/min)