JPS63173620A - Forming process for film of thermoliquid crystalline polymer - Google Patents

Abstract

PURPOSE:To form effectively thermoliquid crystalline resin by achieving inflation forming, while rotating in a specified rotation number the rotary die wherein a die lip and a core rotate in reverse directions mutually. CONSTITUTION:The rotation numbers of a movable lip 2 and a core 3 are regulated in a value equal to or more than the rotation index S shown by a general formula (G: annular slip width, MFI: melt flow index, t: film thickness, BUR: flow up ratio, D: annular slip diameter) and equal to ten times of S value or less. The thermoliquid crystalline thermoplastic resin is fed from a resin path 4, while rotating the movable die lip 2 and the core 3 in reverse directions mutually, and inflation forming is achieved. The thermoliquid crystalline resin whose forming has been difficult, is orientated equally in longitudinal and transverse direction, and the film excellent in tensile strength is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for blown film molding in which a thermal liquid crystal polymer is melt-extruded into a cylindrical shape and then the diameter is expanded to form a film (or sheet). It is.

[Prior art]

In recent years, there has been an increasing demand for materials with excellent rigidity, heat resistance, and dimensional stability, regardless of whether they are fibers, films, or molded products. Although polyester has excellent rigidity and has been widely recognized for its uses, it has not been suitable for uses that require high heat resistance and 1-5 dimension stability. Recently, liquid crystal polynisdels have been attracting attention, and the ones that have been attracting particular attention are J, P, a, P, O, [d,
l, 1 (li76), -〇da 3 and special public show sb-i
This is after W. and J. Jackson announced a thermoliquid crystalline polymer consisting of polyethylene terephthalate and acetoxybenzoic acid in Goib issue. However, these polymers exhibit a high degree of orientation in the molten state, resulting in large anisotropy in mechanical properties, and when formed into films, only films with excessive molecular orientation in the longitudinal direction are produced. The film tends to tear vertically, making it impossible to obtain a film that can be put to practical use.

Various methods have been proposed to solve this problem of molecular orientation in films. For example, there is a method of laminating films with molecular orientation in the -axis direction so that the orientation directions intersect with each other to obtain a high-strength film with no directionality, or a method of obtaining a high-strength film with no directionality, or a method of blow-up ratio (diameter) when performing inflation molding. Examples include a method in which the ratio of the diameter of the expanded cylindrical resin to the diameter of the annular slit of the die is increased, and the degrees of orientation in the longitudinal and lateral directions are matched to make the strength in the longitudinal and lateral directions uniform.

[Problem that the invention seeks to solve]

However, the former method not only increases the thickness of the film but also requires a film forming process and a laminating process, and the operation is complicated. Shitoshi.

In addition, in the latter method, the blow-up ratio is large, so bubbles (wind-shaped portions of the cylindrical film filled with air etc. to expand the diameter) may not stabilize and burst, and the resulting film may have uneven thickness. It has disadvantages such as being large.

[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, the inventors have developed a method using a rotating die in which the die lip and core can rotate in opposite directions. The present inventors have discovered that a film with excellent tensile strength and substantially uniform orientation in the longitudinal and transverse directions can be obtained by inflation molding while rotating the film, thereby completing the present invention.

That is, the present invention consists of a movable die lip and a core that can be rotated in mutually opposite directions through an annular slit and a resin flow path for supplying the thermoliquid crystal polymer to the annular slit during inflation molding of the thermoliquid crystal polymer. Using an inflation molding device having a die, move the movable die lip and core simultaneously in opposite directions or -10,000 to a value greater than or equal to the rotation index (B) shown by the following formula (I), and io of the rotation index (B). The present invention relates to a method for forming a thermal liquid crystal polymer film with improved anisotropy, characterized by carrying out inflation molding while rotating at a rotational speed less than twice as high.

The thermal liquid 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, such as a lower halogen atom, an alkoxy group, or a phenoxy group).

801, CO, an alkylene group, an alkylidene group, or none, and &~ represents a hydrogen atom, a halogen atom, or a hydrocarbon group).

C1 represents a hydrocarbon group, halogen atom, alkoxy group or phenoxy group), SO, CO, alkylene group or alkylidene group or none, and R1 represents a hydrogen atom, a norogen atom or a hydrocarbon group] thing.

(V) A dicarboxylic acid nit represented by the general formula (, Tl).

"-R1-g----------(J) (wherein, at least 60 moles of R1 is /, 4C-phenylene group, Hiro0 mo/L/% The following are /, Hiro-) C1, divalent aromatic hydrocarbon groups other than the unicine group, 0
4-011 monovalent alicyclic hydrocarbon group or O, -0,
・Indicates a monovalent aliphatic hydrocarbon group.

However, the hydrogen atom of the benzene ring of the aromatic hydrocarbon group (/, 4 (including the -phenylene group) is a halogen atom, C1-
(optionally substituted with an alkyl group or alkoxy group of
Goose+Q**Fist s++e**@**e*(Kl (in the formula, R
2 is 01-0.・Monovalent aliphatic hydrocarbon group or 04
〜CI represents a monovalent alicyclic hydrocarbon group) and general formula (oxycarboxylic acid unit represented by Ll -0-R"-!-.........(I, 1 (formula During,
At least 60 mol% or more of R1 is a terphenylene group, 110 mol cs Ja lower /l 4]
Indicates a C0-C1, -valent aromatic hydrocarbon group other than the 22-shine group. However, the hydrogen atom of the benzene ring of the aromatic hydrocarbon group (/, including the terphenylene group) may be substituted with a halogen atom, a C, ~04 alkyl group, or an alkoxy group.

A part of the oxycarboxylic acid unit (υ is bonded to a part of the glycol unit (Kl) through an ether bond to form the general formula (Ml -O-R"-0-R'- (M) (where R1 and R1 are R2 in the (KJ and partial) formula
and Ra] If the dicarboxylic acid unit is composed of a unit represented by Carboxylic acid”=
Ratio of oxycarboxylic acid units (I, l) to the total amount of (L) (Ll / (,71+ (Ll is 30
−j Q % Multi-acid, glycol unit (Kl) and oxycarboxylic acid unit (oxycarboxylic acid unit (I) relative to total LIO
, the ratio of l (TJ / (Kl + (Ll is 3θ~t
Omo/l/ % acid, glycol unit (K) unit to K) (proportion of Ml (binding/(K) in o-go molti).

In a mixed solution of phenol and tetrachloroethane/:/ (weight ratio) 0. The logarithmic viscosity ηinh measured at 30°C at a concentration of jtt/dl is 0.1ldt/? A copolymerized polyester having the above properties. etc.

Furthermore, the above-mentioned polyesters (i.e., IJI) as shown in [■] to [bean] below are substantially composed of a single structure.

D - C1 or CHa].

(Yl　-?-consisting of.

(, AA, consisting of l-αQXz-.

&,”K◇4- (It consists of A Lee-oaHmc.

(In the formula, X represents C1, Br, OL).

thing.

consisting of

of.

etc. Among them, those shown in (I) to (V) are preferably 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 1 Particularly preferred are copolyesters obtained by polymerization. The acylating agent is preferably acetic anhydride, and the amount used is preferably at least 15 times that of hydroxybenzoic acid.

The method for producing the above-mentioned copolyester is as follows.

For example, polyethylene tere-7-talate toh)-a-xybenzoic acid is placed in a reaction vessel with an acylating agent, and /30-2
A copolymerized oligomer is obtained by reacting at 30° C. for 30 minutes or more, preferably for 3 hours.

14 including the next one! Polymerization is carried out at 0 to 100°C to obtain a product.

Alternatively, after forming polyethylene tere-7-thalerate and human sesame, acylation can be carried out by adding an acylating agent (ioo to 50°C for 30 minutes or more, and then polymerizing at 300°C to 300°C to obtain a product. can.

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

Tin compounds (e.g., stannous acetate) are effective in the production stage of copolymerized oligomers, and zinc compounds (e.g., zinc acetate) are effective in the final polymerization reaction.The amount of catalyst added depends on the amount of produced polymer. !0-5000 ppm, preferably 100--000 ppm.

The raw material supply ratio of polyethylene terephthalate and hydroxybenzoic acid for producing the above-mentioned copolymerized polyester is 35 mol% of polyethylene terephthalate to hydroxybenzoic acid? It is suitably used in a ratio of J to 65 molti.

In addition, as the blown film forming device used in the present invention, any type of device that is normally used can be used, but the forming die is different from a normal circular die, and the annular gouer and the core are mutually connected. A rotating die that can rotate in opposite directions is used. An example of a die used in the present invention is shown in FIG.

In FIG. 1, the die includes a movable dies f27 that can be rotated in mutually opposite directions through an annular slit (I), a core (31, and the annular slit) (resin channel for supplying thermoplastic resin to I7). It consists of 41.

In the present invention, a thermoplastic resin is molded under specific molding conditions using a blown film molding apparatus equipped with the above-mentioned rotating die.

First, in the blown film forming apparatus, since the movable dicing (2) and the core (37) are rotated in opposite directions, the film extruded from the annular slit (I) is rotated in a direction that is a combination of the extrusion direction and the rotation direction. Since the notes will be recorded, a film with oblique molecular orientation is obtained as a whole.The degree of molecular orientation of this film is adjusted by adjusting the rotation speed of the movable die lip and core, the extrusion speed of the resin, the take-up speed, etc. Accordingly, the selection is determined as appropriate.

In the present invention, in order to produce a film with excellent tensile strength, a movable die lip (2) and a core (
3) rotational speed (when rotating the movable die lip and the core in opposite directions at the same time, the sum of the rotational speeds of both, or when rotating only one of them, the rotational speed),
Rotation index represented by the following formula (I) (a value greater than or equal to 81 and less than or equal to io times the S value, preferably 7.0 times the S value to 1
It is adjusted to 0 times, more preferably within the range of 3 to 10 times the S value.

Here 8 = rotation index G = annular slit Q width (I) t = Film thickness (demon) BUR = blow-up ratio D = diameter of the annular slit (to) represents.

In addition, the above rotation index (8 (is an important index for the molding operation conditions of the present invention), the fluidity of the resin used (MIF process), the film thickness (t), the blow-up ratio (B [7R), the die used] The slit width (Gl) and slit diameter (for DJ,
This defines the required minimum total rotational speed (rpm).

When the rotation speed specified above is smaller than the rotation index fsl, the strength of the obtained film is not much different from that of conventional molded products with high blow-up ratios, and the effects of the present invention can be fully exhibited. do not have. In addition, if the rotational speed is more than 70 times the rotation index (81), 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. There is a risk that this will happen, which is not desirable.

Further, the extrusion speed and one-piece speed of the resin are set to the same speed as that normally used in inflation molding.

The molding temperature when carrying out inflation molding using the above-mentioned thermal liquid crystal polymer is such that the melt 7o-index of the thermal liquid crystal polymer is equal to or less than 0.02 mm, preferably 0.02 to 0.0 mm.
f710 minutes, more preferably at a temperature in the range of 0.2 to 109710 minutes. If the melt 70-index is larger than the above upper limit, the stability of the bubble may be poor, which is not preferable.

In the present invention, melt 70-index means that the above-mentioned thermoliquid crystal polymer is
Value measured in accordance with S K6760 IIC (f/10
minutes].

In the present invention, the disadvantage (as described above) is solved by increasing the blow-up ratio during inflation molding, but the blow-up ratio used in the present invention is o, b~
! , preferably in the range of 1 to 3, may be as low as possible.

Further, the diameter of the die (the range of Dl is determined by the relationship between the blow-up ratio and the product width) is not particularly limited.

Furthermore, the thickness of the formed film is +11.

- to 300μ, preferably jS-10θμ.

Example 1 (I) Production method of thermoliquid crystal polymer
0. //di/l ) / '/, to λ! fi(I00
mol] and p-hydroxybenzoic acid jj, Koyu (DaOO morn), and acetic anhydride 110.Kkg and stannous acetate λ
3. Put 3 koyu into a polymerization tank equipped with a stirrer, and add 3
After purging twice, the polymerization tank was heated to isθ°C and stirred for 1 hour, then stirred at 170°C for 1 hour without distilling off the acetic acid, and further stirred at 0°C for 1 hour. Furthermore, the temperature of the polymerization tank is S℃
The pressure was gradually reduced to prevent acetic acid from distilling out, and after 30 minutes the pressure was reduced to 0. / j dt. Next, the polymerization system was returned to normal pressure with N, and zinc acetate dihydrate was added thereto at 0.5 g. / t wEt vacuum for 6 hours to complete the polymerization, and the polymerization tank was removed and the above-produced hot liquid crystal polymer was placed in a Modern Machinery @ Cracked Delcer 65g type extruder with annular slit diameters ioo, p, and annular slit width ( Using an inflation molding machine equipped with a spiral-shaped rotary die (a rotary die with the shape shown in the figure) that allows the die lip and core to rotate in opposite directions through an annular slit. , MIF process 0.3t/10min blow-up ratio (B
A 50 μm blown film was produced under the conditions of TJR) / , draft rate 12, and rotation speed shown in Table 1. The obtained film was evaluated by the following measuring method.

The results are shown in Table 1.

Tensile) Strength: Cut the film into strips, pull at 50OX for 1 minute using a tensile tester, and read the strength when the film is cut. Example 3 The same procedure as in Example 1 was carried out except that the rotation speed was changed to the conditions shown in the table. The results are shown in Table/.

The same procedures as in Comparative Example/--Example/ were carried out except that the blow-up ratio and rotation speed were changed to the conditions shown in Table/. The results are shown in Table/.

Table / [Effects of the Invention] According to the method of the present invention, it is possible to successfully mold a thermoliquid crystalline polymer that has been difficult to mold, and it is possible to obtain a film having no directionality in terms of strength.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an example of an apparatus used in the method of the present invention. In the figure, l indicates an annular slit, C indicates a grip, 3 indicates a core, and Hiroshi indicates a resin flow path. Applicant: Mitsubishi Chemical Industries, Ltd. Agent: Patent attorney - (7 others)

Claims (1)

[Claims] In inflation molding a thermal liquid crystal polymer,
Using an inflation molding device having a die consisting of a movable die lip and a core that can be rotated in mutually opposite directions through an annular slit, and a resin channel that supplies thermal liquid crystal polymer to the annular slit, the movable die lip and the core are simultaneously formed. The opposite direction or only one side is greater than or equal to the value of rotation index (S) shown by the following formula (I), and 1 of the rotation index (S)
A method for molding a thermoliquid crystal polymer film with improved anisotropy, which comprises performing inflation molding while rotating at a rotational speed of 0 times or less. S=(30×G×MFI＾■＾■＾2)/(t×BUR
＾■＾■＾7×D)…(I) However, [G: Width of the annular slit (m/m) MFI: Melt flow index at molding temperature (
g/10 minutes) t: Film thickness (m/m) BUR: Blow-up ratio D: Diameter of annular slit (m/m)]