JP2002283431A - Method for manufacturing long-sized molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a long-sized molding having excellent durability reinforced by a liquid crystal resin, heat resistance, moldability, executability and recyclability. SOLUTION: The method for manufacturing the long-sized molding comprises the steps of supplying a copolymer containing a vinyl aromatic hydrocarbon component and an acrylic component as main constituent components, and a liquid crystal having a higher transition temperature than the moldable temperature of the copolymer to an extruder, melt extruding a mixed resin, supplying the melt extruded mixed resin to a mold at a temperature higher than the transition temperature of the resin, passing the resin through a passage provided in the mold and gradually decreasing in its sectional area, then cooling the resin to the transition temperature or lower of the resin, and then shaping the resin to a desired shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a long molded article.

[0002]

2. Description of the Related Art As a plastic product having excellent rigidity, impact resistance, and recyclability, a method for producing a long molded article composed of a fibrillated fibrous liquid crystal resin and a thermoplastic resin has been known. JP-A-9-85796, etc.).

[0003] In the above method, polyolefin, vinyl chloride resin or the like is used as the thermoplastic resin. However, since the polyolefin is decomposed by ultraviolet rays contained in sunlight, the surface layer is coated for outdoor use. It is necessary to block ultraviolet rays. However, since polyolefin is nonpolar, it is difficult to coat a highly weatherable resin. In addition, current plastic products are generally connected to various parts using solvent-based adhesives during installation and other work.However, polyolefins have high solvent resistance and are difficult to bond, so workability is poor. Inferior.

On the other hand, since the vinyl chloride resin has a low thermal decomposition temperature and is easily decomposed, there are many restrictions on the transition temperature of the liquid crystal resin mixed and melted, and it is difficult to use the resin together with a highly rigid liquid crystal resin. Furthermore, it is difficult to use resins exemplified as thermoplastic resins in the above publications as building materials outdoors because of their durability, heat resistance, moldability, and workability.

[0005]

[Problems to be solved by the invention]

An object of the present invention is to solve the above-mentioned problems and to provide a method for producing a long molded article reinforced with a liquid crystal resin and having excellent durability, heat resistance, moldability, workability, and recyclability. I do.

[0007]

Means for Solving the Problems The process for producing a long molded article of the present invention is directed to a copolymer comprising a vinyl aromatic hydrocarbon component and an acrylic component as main components (hereinafter simply referred to as "copolymer"). ) And a liquid crystal resin having a transition temperature higher than the moldable temperature of the copolymer are supplied to an extruder and melt-extruded, and the melt-extruded mixed resin is molded at a temperature not lower than the transition point of the liquid crystal resin. The liquid crystal resin is passed through a passage provided in the mold, the cross-sectional area of which is gradually reduced, and then cooled to a temperature equal to or lower than the transition temperature of the liquid crystal resin, and then shaped into a desired shape.

[0008] The thermoplastic resin used in the present invention comprises a copolymer having a vinyl aromatic hydrocarbon component and an acrylic component as main components.

The copolymer is not particularly limited as long as it is mainly composed of a vinyl aromatic hydrocarbon component such as styrene and an acrylic component such as acrylic acid or an acrylic ester or a derivative thereof. If the amount of the aromatic hydrocarbon component is too small, the resin is liable to decompose when heated above the transition temperature of the liquid crystal resin during melt extrusion.Therefore, the usable liquid crystal resin is limited, and if the acrylic component is too small, the weather resistance is insufficient. When the surface layer is coated with a highly weather-resistant resin to impart a high degree of weather resistance, the fusion property with the resin to be coated is reduced. Ingredients 25 to
Preferably it is 75% by weight.

The liquid crystal resin used in the present invention can maintain a crystal structure in a molten state, easily align molecular orientation by external stress such as shearing, and improve mechanical strength and the like. It is not particularly limited as long as it is a thermotropic liquid crystal resin having a transition temperature higher than the moldable temperature of the polymer, and a main chain type polymer liquid crystal such as wholly aromatic polyester, semi-aromatic polyester, polyesteramide, polycarbonate, polyether, etc. Side chain type polymer liquid crystals such as vinyl polymers and polysiloxanes; and polypeptide type polymer liquid crystals. These may be used alone or in combination of two or more.

The moldable temperature of the above-mentioned copolymer refers to a temperature at which the copolymer exhibits sufficient plasticity to enable ordinary molding such as extrusion molding, and is usually carried out at a temperature 80 ° C. or more higher than the Vicat softening point. is there.

In the present invention, the copolymer and a liquid crystal resin having a transition temperature higher than the moldable temperature of the copolymer are supplied to an extruder and melt-extruded. The liquid is supplied to a mold at a temperature equal to or higher than the transition point of the liquid crystal resin, and is passed through a passage provided in the mold and having a gradually decreasing cross-sectional area.

By doing so, the liquid crystal resin in the mixed resin can be subjected to shear stress to be fibrillated, and then cooled to a transition temperature of the liquid crystal resin or lower to solidify the liquid crystal resin while being fibrillated. can do.

In the present invention, the above-mentioned mixed resin is cooled to a temperature lower than the transition temperature of the liquid crystal resin and then shaped into a desired shape. In this case, once the mixed resin is extruded into a strand or a sheet and solidified, and then appropriately cut or the like to obtain a molding material such as a pellet, the extruder or the like is used again to lower the transition point of the liquid crystal resin below the copolymer. It may be heated above the moldable temperature and passed through an extrusion die having a passage having a desired cross-sectional shape, or a passage having a cross-sectional area that gradually changes from a passage having a gradually decreasing cross-sectional area to a desired cross-sectional shape. It may be shaped into a desired shape using an extrusion die.

In the present invention, in addition to the above-mentioned mixed resin, if necessary, flame-retardant materials such as halogen-based, non-halogen-based and inorganic materials; antioxidants such as hindered amines; modifiers such as modified polyolefins and various elastomers; An inorganic or organic filler may be added.

In the present invention, when a long molded product is obtained, an acrylic resin, an AXS copolymer (where A: acrylonitrile component, X: rubber component other than butadiene,
By coating a highly weatherable resin such as (S: styrene component) by coextrusion, the weatherability of the long molded article can be improved. The high weather resistant resin to be coated is not particularly limited.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing an example of a production apparatus for obtaining a molding material in the method for producing a long molded body of the present invention.

In FIG. 1, 1 is an extruder, and 12 is a mold. As shown in FIG. 1, the production apparatus includes an extruder 1, a cooling water tank 2, and a winding device 3. In the extruder 1, a feeder 11 is mounted on the upstream side, and a mold 12 is mounted on a distal end on the downstream side. The mold 12 is provided with a passage 121 whose sectional area gradually decreases as shown in an enlarged manner in FIG.

In order to obtain the molding material used in the present invention, a copolymer having a vinyl aromatic hydrocarbon component and an acrylic component as main components and a transition temperature higher than the moldable temperature of the copolymer are required. Feeder 1 with a liquid crystal resin having
1 to the extruder 1 and melt-extruded, and the melt-extruded mixed resin is supplied to the mold 12 at a temperature equal to or higher than the transition temperature of the liquid crystal resin, and the cross-sectional area provided in the mold 12 is gradually increased. The liquid crystal resin passes through the decreasing passage 121 and then passes through the cooling water tank 2 to be cooled to a temperature lower than the transition temperature of the liquid crystal resin. The cooled mixed resin is taken up by the take-up device 3 to form the molding material 4, and is cut into a desired size by a pelletizer (not shown).

FIG. 3 is a schematic view showing an example of a production apparatus for producing the long molded article of the present invention from the molding material.

As shown in FIG. 3, the present manufacturing apparatus includes a first extruder 5, a second extruder 7, a cooling mold 6, and a take-up machine 8.
And a cutting device 9. The first extruder 5 has a feeder 51 on the upstream side and a co-extrusion mold 5 on the distal end on the downstream side.
2 is attached, and a passage (not shown) in the co-extrusion mold 52 is communicated with the first extruder 5 and the second extruder 7. Downstream of the co-extrusion mold 52, a cooling mold 6, a take-off machine 8, and a cutting device 9 are provided in this order.

In order to produce the long molded article of the present invention using the production apparatus shown in FIG. 3, first, the molding material is supplied from the feeder 51 to the first extruder 5 and melt-extruded. On the other hand, a highly weather-resistant resin such as an AXS-based copolymer is supplied to the second extruder 7 to be melt-extruded and merged in a passage in the co-extrusion mold 52. Next, after being cooled and solidified by the cooling mold 6, it is supplied to the cutting device 9 while being taken up by the take-off machine 8, and the long molded body 10 cut into a desired size is obtained.

[0023]

EXAMPLES The present invention will be described in more detail with reference to examples.

Example 1 80% by weight of a styrene-acrylic copolymer (manufactured by A & M Styrene, product number "SX200", Vicat softening point 100 ° C., 45% by weight of styrene component), and a wholly aromatic polyester liquid crystal resin 20% by weight (manufactured by Polyplastics, trade name “Vectra A950”, transition temperature: 285 ° C.) was used as an extruder 1 (a twin screw kneading extruder manufactured by Nippon Steel Works, model “TEX44”, screw diameter: 44 mm) shown in FIG. 2), and the passage 121 (the maximum diameter of which is 30 m) whose cross-sectional area gradually decreases as shown in FIG.
m, a minimum diameter of 10 mm, and a taper part length of 40 mm).

Next, the resin mixture is introduced into a cooling water tank 2 filled with cold water adjusted to a temperature of 10 ° C., cooled and wound up by a winding device 3 to obtain a strand-shaped molding material 4 having a diameter of 1.5 mm. Was.

The obtained strand-shaped molding material 4 is cut into a length of 6 mm by a pelletizer (not shown).
The first extruder 5 of the manufacturing apparatus shown in FIG.
1 and melt-extruded, and a passage 523 in the co-extrusion mold 52 (not connected to the second extruder 7) shown in FIG.
(A mold temperature of 230 ° C.).

Then, after being cooled and solidified by the cooling mold 6,
It is supplied to the cutting device 9 while being picked up by the picking-up machine 8 and the length 10
It is cut into 00mm, and a U-shaped long molded body (width 100m
m, height 50 mm, thickness 2 mm).

(Embodiment 2) The second embodiment of the manufacturing apparatus shown in FIG.
Acrylonitrile- (ethylene-diene) -styrene copolymer (manufactured by Japan A & L Co., Ltd., trade name “Unibright UB400”) was supplied to the extruder 7 of Example 1 and extruded in the same manner as in Example 1 except for co-extrusion. A long molded body 10 having a cross-sectional shape shown in FIG.
m).

(Embodiment 3) The first embodiment of the manufacturing apparatus shown in FIG.
80% by weight of the same styrene-acryl copolymer as in Example 1 and 20% by weight of a wholly aromatic polyester-based liquid crystal resin were supplied from a feeder 51 to the extruder 5 by dry blending. Instead of 52, it is supplied to a co-extrusion mold 53 (having a resin flow portion 531 and a drawing flow portion 532 adjusted to 290 ° C. and a development flow portion 533 adjusted to 230 ° C.) shown in FIG. Except having done, it carried out similarly to Example 1, and obtained the long molded object 100 shown in FIG.

Example 4 A U-shaped liquid crystal resin was prepared in the same manner as in Example 1 except that a semi-aromatic polyester liquid crystal resin (trade name “Rodrun LC5000G”, manufactured by Unitika Ltd., transition temperature: 280 ° C.) was used as the liquid crystal resin. A long molded article having a shape of was obtained.

(Comparative Example 1) Example 1 was repeated except that the mold 12 was replaced with a mold whose temperature was controlled at 290 ° C. (resin temperature) having a passage (diameter 30 mm) having a constant cross-sectional area. In the same manner, a U-shaped long molded body was obtained.

(Comparative Example 2) A U-shaped length was obtained in the same manner as in Example 1 except that high-density polyethylene (manufactured by Mitsubishi Plastics, product number "HE420") was used instead of the styrene-acrylic copolymer. A compact was obtained.

Comparative Example 3 A long molded article 10 was produced in the same manner as in Example 2 except that high-density polyethylene (manufactured by Mitsubishi Plastics, product number "HE420") was used instead of the styrene-acrylic copolymer. I got

Comparative Example 4 A vinyl chloride resin (melting temperature 170 ° C.) was used instead of the styrene-acrylic copolymer.
A molding material was produced in the same manner as in Example 1 except that a resin composition comprising 0 parts by weight, 2 parts by weight of a tin-based stabilizer, and 1 part by weight of a lubricant was used. The resin was decomposed, and a molding material could not be obtained.

(Comparative Example 5) A long molded body 10 was obtained in the same manner as in Example 2 except that impact-resistant polystyrene (manufactured by A & M Styrene, product number "H8662") was used instead of the modified acrylic polystyrene. .

Evaluation of physical properties Coefficient of linear expansion The coefficient of linear expansion in the extrusion direction of the elongated molded products obtained in Examples 1 and 3 and Comparative Examples 1 and 2 was measured by a thermal analysis module (Model “TMA100” manufactured by Seiko Instruments Inc.). It measured using.

Fusing Strength The fusing strength between the surface resin and the base resin of the long molded articles obtained in Example 2 and Comparative Examples 3 and 5 was measured by a cross-cut peel test.

Weather Resistance The long molded articles obtained in Examples 1 and 2 were exposed for 2000 hours by an accelerated exposure tester (trade name “Super Xenon Weather Meter WEL-SAN-HC” manufactured by Suga Test Instruments Co., Ltd.). The change in color tone before the exposure was evaluated using a color difference meter.
The above results are summarized in Table 1.

[0039]

[Table 1]

[0040]

According to the method for producing a long molded article of the present invention, a copolymer containing a vinyl aromatic hydrocarbon component and an acrylic component as main components and a transition temperature higher than the moldable temperature of the copolymer are provided. Is supplied to an extruder and melt-extruded, and the melt-extruded mixed resin is supplied to a mold at a temperature equal to or higher than the transition temperature of the liquid crystal resin, and the cross-sectional area provided in the mold is After passing through a gradually decreasing passage, and then cooling to below the transition temperature of the liquid crystal resin, the liquid crystal resin is shaped into a desired shape. Therefore, even if a liquid crystal resin is used, durability, heat resistance, moldability, workability And a long molded body having excellent recyclability can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a production apparatus for obtaining a molding material in a method for producing a long molded body of the present invention.

FIG. 2 is an enlarged sectional view showing a mold used in FIG.

FIG. 3 is a schematic view showing one example of a manufacturing apparatus for manufacturing a long molded body of the present invention.

FIG. 4 is an enlarged sectional view showing a co-extrusion mold used in FIG. 2;

FIG. 5 is a cross-sectional view illustrating an example of a long molded body obtained in Example 2.

FIG. 6 is an enlarged sectional view showing a co-extrusion die used in Example 3.

FIG. 7 is a sectional view showing an example of a long molded body obtained in Example 3.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Extruder 12 Die 52, 53 Co-extrusion die 121, 531 Passage 10, 100 Long molded object

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C08L 101/00 C08L 101/00 // B29K 25:00 B29K 25:00 F term (reference) 4F071 AA22X AA31X AA33X AA34X AA43 AA76 BA01 BB06 BC07 4F207 AA13E AA20E AA24 AC01 KA01 KA17 KB21 KF01 KJ08 KK04 KK54 KL83 4J002 AD032 BC071 BG011 BG041 BG101 CF162 CG002 CH002 CL082 CP032 FD070 FD130

Claims (1)

[Claims] 1. An extruder comprising: a copolymer mainly composed of a vinyl aromatic hydrocarbon component and an acrylic component; and a liquid crystal resin having a transition temperature higher than a moldable temperature of the copolymer. Melt extrusion, melt-extruded mixed resin,
The liquid crystal resin is supplied to a mold at a temperature equal to or higher than the transition temperature of the liquid crystal resin, passed through a passage provided in the mold, the cross-sectional area of which gradually decreases, and then cooled to a temperature equal to or lower than the transition temperature of the liquid crystal resin. A method for producing a long molded body, which is shaped into a shape.