JP3399680B2 - Method for melt extrusion molding of polyolefin resin - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for melt extrusion molding of a polyolefin resin. Specifically, when melt-extrusion molding polyolefin resin, it is necessary to suppress the adhesion of polyolefin resin “Mani” to the extrusion surface of the molding die, and to stably mold high-quality molded products at high speed. And a method for melt extrusion molding of a polyolefin resin. Conventionally, pipes such as water pipes and gas pipes, and inflation films such as plastic bags and heavy bags for fertilizer have been used as extruded products of polyolefin resins. However, in recent years, an improvement in productivity has been more strongly demanded from the viewpoint of economy, and a further increase in the amount of extrusion at the time of molding has been achieved. However, when the polyolefin resin is melt-extruded at a high discharge rate, a so-called “meani”, such as a degraded product of the polyolefin resin or a part of the additive, or an oxide or a decomposition product thereof, is formed on the extrusion surface of the die. Since this occurs and adheres, this “meani” adheres to the surface of the molded product extruded from the die or generates streaky irregularities on the surface of the molded product, causing deterioration in the quality of the molded product. I was Therefore, such "Mayani"
In order to remove the material from the extrusion surface of the die, it is difficult to temporarily improve the productivity by temporarily suspending the molding and cleaning the extrusion surface of the die. Met. For this reason, a metal soap such as magnesium stearate or a lubricant such as stearic acid amide is added to the polyolefin resin that is melt-extruded to improve the slipperiness with the die wall surface and prevent the occurrence of “measles”. Various methods have been proposed. However, in the method of adding a lubricant such as a metal soap such as magnesium stearate or a stearic acid amide to the melt-extruded polyolefin resin to improve the slipperiness with the die wall, the improvement effect is low, and Due to the addition of the lubricant, there is a problem that the heat-fusing property at the time of molding is reduced, and the effect of the additive blended for improving the physical properties of the molded article such as antistatic performance and blocking is adversely affected. Has occurred. Accordingly, it is possible to prevent the occurrence of "measuring" on the extrusion surface of a die in melt extrusion molding of a polyolefin resin, and to have no adverse effect on the physical properties of the obtained molded article. An object of the present invention is to provide a new method for melt extrusion molding of a polyolefin resin. SUMMARY OF THE INVENTION [0004] In view of the above-mentioned problems relating to melt extrusion molding of polyolefin resins, the present inventors have developed a die having no adverse effect on various physical properties of a molded article. As a result of intensive studies to prevent the occurrence of "measles" on the extruded surface, the polyolefin resin contained a predetermined amount of carboxylic acid amide-based wax, and the shearing rate at the die outlet was reduced to a certain value or less to melt The present invention has been completed based on the finding that the above object can be achieved by extrusion molding. That is, the melt extrusion molding method of the polyolefin resin of the present invention comprises the step of adding a carboxylic acid amide-based wax to 0.01 part by weight of the polyolefin resin.
It is characterized in that a polyolefin resin composition containing up to 5 parts by weight is melt-extruded under conditions where the shear rate at the exit of the die is 3,000 sec ^-1 or less. [I] Polyolefin resin composition (1) Constituents The polyolefin resin composition used as a raw material in the melt extrusion molding method of the polyolefin resin of the present invention is based on 100 parts by weight of the polyolefin resin. The carboxylic acid amide-based wax is blended in an amount of 0.01 to 5 parts by weight and melt-kneaded. (a) Polyolefin resin As the polyolefin resin, ethylene, homopolymer of α-olefin having 2 to 8 carbon atoms such as propylene,
Or, a random copolymer or a block copolymer obtained by random or block copolymerization of two or more of these α-olefins, or a vinyl acetate or an acrylic resin containing the α-olefin as a main component and copolymerizable therewith. Copolymers obtained by copolymerizing other vinyl monomers such as acid esters and acrylic acid, and mixtures thereof. Among these, it is preferable to use a polyethylene resin, a polypropylene resin, and a copolymer resin of ethylene and propylene. The melting index (MI) of these polyolefin resins is 0.01 to 40 g / 1 for polyethylene resins.
Those having a surface defect (thickness) within a range of 0 minute, preferably 0.05 to 10 g / 10 minutes, and 0.1 to 30 g / 10 minutes, preferably 0.2 to 10 g / 10 minutes in the case of a polypropylene resin. This is preferable because spots can be greatly improved. (B) Carboxylic amide wax The carboxylic amide wax is a polycondensate obtained by a dehydration reaction of a mixture of a higher aliphatic monocarboxylic acid and a polybasic acid with a diamine. Can be represented by the general formula (I). General formula (I) R ¹ CO (NHR ² NH) y ¹ (COR ³ CO) _x (N
HR ² NH) y ² COR ¹ (wherein, R ¹ represents a saturated alkyl group having 15 or more carbon atoms, R ² represents an aliphatic or aromatic hydrocarbon group having 2 or more carbon atoms, and R ³ represents a carbon number. Represents one or more aliphatic, aromatic or alicyclic hydrocarbon groups, x is 0.18 to 1.0, y ¹
+ Y ² represents a number between 1.5 to 2.0. Higher aliphatic monocarboxylic acid As the above higher aliphatic monocarboxylic acid, R ¹ at both ends of the polycondensate represented by the above general formula (I) has 15 carbon atoms.
Above, preferably those having 15 to 28 saturated alkyl groups, for example, palmitic acid, stearic acid,
Examples include behenic acid, montanic acid, and hydroxystearic acid. It constitutes R ¹ CO and COR ¹ at both ends of the polycondensate represented by the general formula (I). [0008] As polybasic acids polybasic acid, the general formula (I) in R ³ polycondensates represented has 1 or more carbon atoms, aliphatic preferably 1 to 8, aromatic, alicyclic, Dibasic acid or more, preferably 2-
Tricarboxylic acid carboxylic acid, for example, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, pimelic acid, aliphatic dicarboxylic acids such as azelaic acid, phthalic acid,
Examples include aromatic dicarboxylic acids such as terephthalic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid and cyclohexylsuccinic acid. It constitutes COR ³ CO of the polycondensate represented by the general formula (I). The diamine is an aliphatic or aromatic diamine in which R ^{2 of the} polycondensate represented by the general formula (I) has 2 or more carbon atoms, preferably 2 to 6 carbon atoms. , 3-diaminopropane, hexamethylenediamine, metaxylenediamine, tolylenediamine, paraxylylenediamine, phenylenediamine and the like. N of the polycondensate represented by the general formula (I)
HR ² NH is constituted. [0010] carboxylic acid amide-based wax polycondensates represented by the amount ratio above general formula (I), relative to the higher aliphatic monocarboxylic acid, any softening point by changing the mixing ratio of the polybasic acid The polybasic acid is usually added in an amount of 0.18 to 0.1 mol per 2 mol of the higher aliphatic monocarboxylic acid.
It is preferable to use 1.0 mol and the diamine in the range of 1.5 to 2.0 mol. Production of polycondensate The mixture of the above-mentioned higher aliphatic monocarboxylic acid, polybasic acid and diamine is reacted at 180 to 300 ° C., preferably 200 to 27 ° C.
It is obtained by reacting at a temperature of 0 ° C. for 3 to 7 hours, preferably 3 to 5 hours, for dehydration. These carboxylic acid amide-based waxes of polycondensates represented by the general formula (I) are generally manufactured by Kyoeisha Chemical Co., Ltd. as "Light Amide WH Series", for example, WH-25.
5, commercially available under the trade name of WH-215. (2) Compounding ratio The polyolefin resin composition used in the present invention contains 0.01 to 5 parts by weight, preferably 0.05 to 1 part by weight of a carboxylic acid amide wax based on 100 parts by weight of the polyolefin resin. Part, particularly preferably 0.05 to 0.1 part.
It was blended at a ratio of 5 parts by weight. If the content of the carboxylic acid amide-based wax is too small, the residence time in the die is prolonged, so that the resin is easily deteriorated and the thermal decomposition of the additive is apt to occur. Absent. On the other hand, if the content of the carboxylic acid amide wax is too large, the carboxylic acid amide wax is undesirably agglomerated, leading to deterioration of the quality of the molded product. (3) Preparation of Polyolefin Resin Composition The preparation of the polyolefin resin composition used as the above-mentioned raw material is carried out by blending a carboxylic acid amide-based wax in advance with a polyolefin resin and generally melt-kneading the mixture at a temperature of 180 to 270 ° C. Can be prepared by
Immediately before melt extrusion, it can also be prepared by blending the carboxylic acid amide-based wax with the polyolefin resin. (4) Optional Ingredients The above-mentioned polyolefin resin composition may contain, if necessary, a stabilizer, an antioxidant, an antistatic agent, a plasticizer, a dispersant, a lubricant, etc. which are generally used. And fillers such as titanium oxide, talc, calcium carbonate, and alumina can be added. [II] Melt Extrusion Molding In the melt extrusion molding method of the polyolefin resin of the present invention, it is important to use a polyolefin resin composition having the above specific composition as a raw material. is important. (1) Molding conditions As the extrusion die used in the melt extrusion molding method of the polyolefin resin of the present invention, various extrusion dies generally used in the melt extrusion molding method can be used. Filament dies used for forming monofilaments, multifilaments, ropes, nets, etc., T dies used for forming sheets or films, hollow molding used for forming containers, industrial parts, etc. Dies,
Examples include a profile extrusion die used for extrusion of a pipe frame material, and a laminate die used for molding a laminated film or a laminated sheet. (2) Molding Conditions In the method for melt-extrusion of a polyolefin resin of the present invention, when the polyolefin resin composition is melt-extruded, the shear rate of the molten resin at the exit of the die is 3,000.
It is important that the reaction is performed under the condition of ⁰ sec ^-1 or less, preferably 2,000 sec ^-1 or less, particularly preferably 50 to 2,000 sec ^-1 . If the shearing rate of the molten resin exceeds the above range, the molten resin is scraped off by the edge of the die exit or the contact with the die surface becomes large due to the effect of swelling of the resin, thereby increasing the occurrence of "sticking". In the melt extrusion molding method of the polyolefin resin of the present invention, both the use of the polyolefin resin composition of the specific composition as a raw material, and the shear rate at the die exit at the time of the melt extrusion molding to a specific value or more Unless the conditions are satisfied, the object of the present invention cannot be achieved. The present invention will be described more specifically with reference to the following experimental examples. [I] Evaluation method (1) Printability test Toyo Ink's PKH-105 (red) was applied to the corona-treated surface to a thickness of about 10 μm with a bar coater, and after 24 hours, the following test was carried out. Judgment was made according to the judgment criteria. (a) Tape test: After adhering a 12 mm wide cellophane tape manufactured by Sekisui Co., Ltd. with three finger pressures, half of the adhesive surface was gradually turned up and the other half was turned up sharply. (b) Kneading test: The printing surfaces were rubbed 30 times by finger pressure. (c) Scratch test: Scratched in the TD direction with a claw. (d) Ink flow test: Immerse in water overnight and check the ink flow. Judgment criteria A: Not at all. AB: Some (partially) removal is possible. B: Somewhat large. C: Almost removed. (2) Slip start angle 3 with a friction angle tester (thread: bottom area 100 mm × 63 mm, 1 kg weight) manufactured by Toyo Seiki Co., Ltd.
In an atmosphere of 5 ° C. and 85% RH, the film was placed in the atmosphere for 2 hours or more, and the sliding start angle between the corona-treated surfaces was measured. (3) Friction The corona-treated surface of a film having a charged potential of 200 mm × 170 mm was rubbed with a gauze 20 times, and the charged potential was measured after 30 seconds. (4) Seal strength The obtained blown film was used as an HS 22B-2 type heat sealer manufactured by Neurong Co., Ltd.
0mm, heating section clearance 0.3mm, cooling section length 1
Heat sealing temperature (heating unit surface temperature) 220 ° C., cooling unit temperature 3 using 50 mm, cooling unit clearance 1 mm)
Heat sealing was performed at a position 1.5 cm from the edge of the opening of the cylindrical film under the conditions of 0 ° C. and a film feeding speed of 15 m / sec. The end of the sealing portion of this tubular film is J
IS Z-1702 Punched perpendicular to the sealing direction so as to be at the center of the punching blade, and JIS Z-1702
Create a 1702 punched sample and use JIS Z 170
Under the conditions of 2, the strength up to the breakage of the seal portion was measured. As is clear from Tables 4 and 5, there is no adverse effect. [II] Experimental Examples Example 1 MFR is 0.6 g / 10 min, density is 0.922 g / cm
³ , ethylenediamine as a carboxylic acid amide-based wax with respect to 100 parts by weight of the linear low-density polyethylene of ³ ,
Stearic acid, sebacic acid polycondensate (C ₁₇ H ₃₅ CONH
(CH ₂ ) ₂ NH (CO (CH ₂ ) ₈ CO) _x NH (C
A mixture of 0.2 parts by weight of H ₂ ) ₂ NHCOC ₁₇ H ₃₅ ) (“Light Amide WH-255” manufactured by Kyoeisha Chemical Co., Ltd.) was melted and kneaded at a temperature of 200 ° C. in a 40 mmφ extruder to form pellets. did. This polyolefin resin composition pellet is applied to a Toyo Seiki Labo Plastomill 100C-100 equipped with a 20 mmφ extruder, and 3 mm
165 ° C resin temperature from nozzle φ, 530 sec ^-1
At a shear rate of 420 minutes, and the occurrence of "measles" adhering to the nozzle tip was visually observed. Table 1 shows the results. Comparative Examples 1 to 3 To 100 parts by weight of the same linear low-density polyethylene as in Example 1 and the same linear low-density polyethylene as in Example 1, 0 stearic acid amide and 0 mg magnesium stearate were added. The mixture prepared by mixing 0.2 parts by weight was extruded into a 40 mmφ extruder and melt-kneaded at a temperature of 200 ° C. to form pellets. This polyolefin resin composition pellet was prepared in Example 1.
Under the same conditions as described above, and the occurrence of “measles” adhering to the nozzle tip was visually observed. Table 1 shows the results. From the results in Table 1, it can be understood that the polyolefin resin compositions of Comparative Examples 1 to 3 are significantly inferior in the effect of preventing the occurrence of "stain" as compared with the polyolefin resin composition of Example 1. Examples 2-3 and Comparative Examples 4-5 With respect to 100 parts by weight of the same linear low-density polyethylene as in Example 1, 0.01 part by weight of ethylenediamine, stearic acid and polycondensate of sebacic acid were added. A mixture of 0.05 part by weight, 0 part by weight, and 0.005 part by weight was melt-kneaded at a temperature of 200 ° C. in an extruder of 40 mmφ to form pellets. This polyolefin resin composition pellets are
It is applied to a Toyo Seiki Labo Plastomill 100C-100 equipped with a mφ extruder and 215 from a 3 mm φ nozzle.
The resin was continuously extruded at a resin temperature of ° C at a shear rate of 540 sec ^-1 for 420 minutes, and the occurrence state of "Mayani" adhering to the nozzle tip was visually observed. Table 2 shows the results.
From the results in Table 2, it can be recognized that the additive amount of Comparative Example 5 has a slight effect of preventing the occurrence of "Mani" as compared with the additive amount of Comparative Example 4, but it is necessary to sufficiently prevent the occurrence of "Mani". However, it can be understood that the addition amount is required to be approximately equal to or more than the addition amount of Example 2. Examples 4-5 and Comparative Example 6 0.05 parts by weight of ethylenediamine, stearic acid, and sebacic acid polycondensate were blended with 100 parts by weight of the same linear low-density polyethylene as in Example 1. To 40m
The mixture was melt-kneaded at a temperature of 200 ° C. in an extruder of mφ to form pellets. The polyolefin resin composition pellets are applied to a Toyo Seiki Labo Plastomill 100C-100 equipped with a 20 mmφ extruder, and a resin temperature of 230 ° C., 2,000 sec ⁻¹ or 3,000 sec ⁻¹ shearing from a 1.5 mm φ nozzle. It was continuously extruded at a speed, and the occurrence state of “measles” adhering to the nozzle tip was visually observed. Table 3 shows the results. From the results shown in Table 3, it can be understood that the melt extrusion under the extrusion conditions of the present invention has an effect of preventing the occurrence of “measles”. Examples 6-7 and Control 1 MFR 0.3 g / 10 min, density 0.926 g / cm
Ethylenediamine, stearic acid, sebacic acid polycondensate (Kyoeisha Chemical Co., Ltd. “Light Amide WH-25”) with respect to 100 parts by weight of linear low-density polyethylene ³
5)) was blended with 0 part by weight, 0.04 part by weight, and 0.1 part by weight, and melted and kneaded at a temperature of 220 ° C. in an extruder having a diameter of 50 mm to obtain pellets. The polyolefin resin composition pellets were obtained from Modern Machinery Co., Ltd.
Using an inflation molding machine equipped with an inflation die having an annular slit diameter of 200 mmφ and a slit width of 3 mm and a cooling air ring in
0 kg / hr, blow-up ratio is 1.4, draft rate is 2
A blown film having a thickness of 150 μm was obtained under the conditions of 4, and the surface tension due to the wetting reagent was 42 dyne / c.
m was subjected to corona treatment. This blown film was stored in an atmosphere at a temperature of 23 ° C. and a humidity of 50%, and the physical properties at the time when 17 days had passed after the molding were confirmed. The results are shown in Tables 4 and 5. [Table 1] [Table 2] [Table 3] [Table 4] [Table 5] The melt-extrusion molding method of the polyolefin resin of the present invention uses a polyolefin resin composition of a specific composition and melt-extrusion-molds under specific conditions to reduce the "Mayani" during molding. Since the adhesion is suppressed, it is possible to stably mold a high-quality molded product at a high speed without adversely affecting the physical properties of the molded product, so that productivity is high,
This is an economically advantageous method.

────────────────────────────────────────────────── (5) Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI C08L 77:06) (56) References JP-A-6-234890 (JP, A) JP-A-60-188438 (JP, A) JP-A-6-333973 (JP, A) JP-A-6-344416 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 47/00-47/96 C08J 5/00 C08K 5/20 C08L 23/00

Claims (1)

(57) [Claim 1] A polyolefin resin composition containing 0.01 to 5 parts by weight of a carboxylic acid amide-based wax per 100 parts by weight of a polyolefin resin, and a shear rate at a die outlet of 3 is used. , characterized by melt extrusion under the conditions of 000Sec ^-1 or less, a melt extrusion molding method of a polyolefin resin, the carboxylic acid amide-based wax is a mixture of higher aliphatic monocarboxylic acid and a polybasic acid Extrusion molding method of polyolefin resin, which is a polycondensate of diamine and diamine.