JPH05220812A - Mouthpiece for manufacturing resin composition for molding - Google Patents

Abstract

PURPOSE:To prevent the mixing of an eye mucus-like matter into a product, and to improve the quality of the product by coating sections near the internal surface of the discharge hole of a mouthpiece and the outlet of the discharge hole with a fluororesin in the mouthpiece used as a discharge section at a time when a molten resin composition for molding is discharged in a gut shape. CONSTITUTION:In a mouthpiece 1 used as a discharge section at a time when a resin composition for molding is discharged in a gut shape, sections near the internal surfaces 3 of the discharge holes 2 of the mouthpiece and the outlets of the discharge holes 2 are coated with a fluororesin. A resin containing a fluorine component such as polytetrafluoroethylene, tetrafluoroethylene- perfluoroalkyl vinyl ether, etc., is employed as the fluororesin. Accordingly, when the resin composition for molding is manufactured continuously, the sublimate of a residual monomer and a residual oligomer contained in the resin often generated near the outlet of the discharge hole of the mouthpiece 1 of an extruder, etc., and resin composition itself, an eye mucus-like colored foreign matter, are peeled easily from a metallic surface, thus preventing the adhesion and deposition of the sublimate and foreign matter.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an extruder, a kneader, a polymerizer in a manufacturing process of a resin melted in a manufacturing process of a resin material and a molding resin composition containing various fillers and additives. The present invention relates to a mouthpiece used for a discharge part such as.

[0002]

2. Description of the Related Art Generally, in order to produce a molding resin composition, a polymer is polymerized from a monomer in a polymerization vessel, or a polymer and various fillers and additives are mixed and kneaded in an extruder or a kneader. A method is used in which these compositions melted from a die having discharge holes of a predetermined size are extruded into a gut shape, cut, and pelletized.

The die for discharging the melt of the molding resin composition is usually made of metal, but a die made of ceramics containing 40% by weight or more of zirconia is also known (special feature). (Kaisho 61-24973).
On the other hand, in spinnerets for fibers, Japanese Patent Publication No. 55-184
Known in JP-A No. 78 are silicon materials such as polydiphenyl siloxane and polymethylphenyl siloxane, and those coated with copper or copper-based metal as known in JP-A-63-105105.

[0004]

However, the die used for discharging the molding resin composition in a molten state, such as the extruder, kneader, and polymerization can, continuously discharges the molding resin composition. If so, so-called eye-shaped colored foreign matter adheres and accumulates near the outlet of the die discharge hole. This candy-like colored foreign matter (hereinafter abbreviated as candy-like substance) is a sublimation product of residual monomers or residual oligomers contained in the resin, a condensate of volatile components of various additives, or a resin composition. They are themselves, or they are deteriorated and discolored, and are attached and deposited near the discharge holes of the die. If the mess-like material adheres and accumulates in the vicinity of the ejection hole of the die and is operated while being deposited, a part of the messiness may be peeled off and adhere to or be mixed with the gut-shaped resin composition that is continuously ejected.

When the resin composition having such a messy material adhered thereto is pelletized as it is, and it is made into a product by a method such as injection molding, a colored mesiness material is formed on the surface of the molded product. There are problems such as appearance and impairing the product quality such as the appearance of the product, resulting in a marked decrease in product value. In the past, methods to prevent the inclusion of messy products in the product have been carried out by regular cleaning of the die discharge surface, scraping from the gut before pelletizing, selection and removal of messy products mixed in the product. However, it cannot be said to be sufficient because the removal rate is low and the time required for selection is enormous, and it is a problem that the manufacturer of the resin composition for molding needs to solve.

The above-mentioned ceramics die was devised for the purpose of preventing the generation of such a body-like substance. In the case of ceramics, although the accumulation of the body is reduced, the precision workability at the time of producing the die is improved. However, there were drawbacks that the discharge holes could not be formed accurately and the manufacturing cost was extremely high. On the other hand, it is also conceivable to apply and apply a silicone-based resin known in the fiber die to the die for the resin composition for molding, but in the fiber die, the purpose of preventing bending of the molten yarn immediately after discharge In this case, the silicone resin is applied, and even if the silicone resin is directly applied to the die for the resin composition for molding, there is almost no effect of preventing the accumulation of the body-like substance.

On the other hand, as a plastic molding die having a small amount of dents, for example, as disclosed in Japanese Patent Laid-Open No. 61-24973, a die made of ceramics containing 40 wt% or more of zirconia is proposed. An object of the present invention is to provide a die for a resin composition for molding, which can prevent mixing of a messy product into a product and can discharge a resin composition for molding excellent in product quality.

[0008]

A die for a molding resin composition of the present invention is a die used for a discharging part when a molten molding resin composition is discharged in a gut shape. The inner surface of the discharge hole and the vicinity of the discharge hole outlet are coated with a fluororesin. The "molding resin composition" in the present invention means a resin (single resin) used for molding such as injection molding and extrusion molding, a composition of a resin and another resin (resin alloy), a single resin or a resin alloy thereof. It is a general term that includes reinforcing fibers, fillers, compositions containing additives, and the like.

The "mold for producing a molding resin composition" is a spinneret used in a discharging part when the above molding resin composition is melted and discharged in a gut shape, and is a spinning fiber for discharging. It does not include a base or a base for discharging a film. Representative examples of a die for producing a molding resin composition used in the present invention are shown in FIGS. FIG. 1 is a front view (discharging side) of a die, FIG. 2 is a rear view (extruder side), FIG. 3 is a cross-sectional view, and FIG. 4 is an overview of an extruder equipped with a die of the present invention and a gut. FIG. A plurality of ejection holes 2 penetrates the die 1, and the molten resin composition enters from the direction of arrow A, passes through the inner surface 3 of the ejection hole, is extruded in a gut shape from the outlet of the ejection hole, and is cooled and solidified. .. 4 is the vicinity of the discharge hole outlet covered with a fluororesin.

The fluororesin mentioned here means polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether, tetrafluoroethylene.
Hexafluoropropylene copolymer, polychlorotrifluoroethylene, tetrafluoroethylene / ethylene copolymer. Examples thereof include resins containing a fluorine component such as chlorotrifluoroethylene / ethylene copolymer, polyvinylidene fluoride, and polyvinyl fluoride.

The coating method is, as generally known,
As a pretreatment for the base die, degreasing / baking / polishing / cleaning the surface to form a fluororesin coating film, and then undercoating / drying / firing / quenching the fluororesin to form a fluororesin coating film. Method etc. are mentioned. Further, this coating film forming treatment may be repeated several times depending on the thickness of the coating film to be formed. The thickness of the coating film is preferably 0.01 mm to 0.1 mm. If it is too thick, it will peel off and mix into the product, and if it is too thin, it will have a short life.

Further, using a base coated with a fluororesin,
Then, by spraying a gas at a temperature and air volume that does not cause clogging of the mouth of the mouth of the mouthpiece, such as air, nitrogen, or steam, it is possible to completely prevent mixing of the wastewater products into the product. More preferable. The temperature of the sprayed gas is 100 ° C to 400 ° C, preferably 200 ° C.
The range of ℃ ~ 300 ℃ is good. The air volume is 10Nl / min to 50Nl / min per discharge hole and the air velocity is 50 to 100m.
/ Sec is preferable.

[0013]

[Operation] In the manufacturing process of a molding resin composition, a messy product is generated near the outlet of a discharge hole of a die used for a discharge part of an extruder, a kneading machine, a polymerization can, and the like, and adheres and deposits.
It is considered that this is due to the adhesion of the porcelain particles to the metal. That is, in the vicinity of the outlet of the discharge hole, because of the high temperature, the body-like material is partially in a molten state and has a high affinity with the metal.
Easy to attach. In the present invention, by forming a fluororesin coating on the vicinity of the discharge hole outlet of the die and the inner surface of the discharge hole, peeling from the metal surface of the canny-like material can be facilitated and adhesion and accumulation can be prevented, and the product can be put into the product of the canny-like material. It is considered possible to prevent the mixture of

[0014]

EXAMPLES The present invention will be specifically described below with reference to examples. Example 1 Nylon 6, 70 parts by weight and glass fiber (E
Glass chopped strand), melts 30 parts by weight
The mixture was kneaded and extruded to form a strand, which was cut and pelletized. As the die of the ejection part, a die having an ejection hole outlet and an inner surface of the ejection hole covered with polytetrafluoroethylene was extruded from the die (ejection hole diameter: 4 mm), and the amount of the meyani-like substance mixed into the product pellet was measured.

A die made of tool steel was used, and polytetrafluoroethylene was coated by the following method. First,
After degreasing the spinneret, bake and etch at approximately 400 ° C for 15 minutes.
After surface treatment / washing such as washing with water, primer is undercoated, dried at 130 ° C for 1 hour, baked at 400 ° C for 1 hour and rapidly cooled, and then enamel is applied as the topcoat, and the same drying / baking / quick cooling is performed. Then, spray polytetrafluoroethylene on the inner surface of the mouth of the mouthpiece and the vicinity of the outlet of the mouthpiece to a thickness of 0.
A coating film of 01 to 0.02 mm was formed. The results are shown in Table 1.

Example 2 6,70 parts by weight of nylon and glass fiber (E
Glass chopped strand), melts 30 parts by weight
The mixture was kneaded and extruded to form a strand, which was cut and pelletized. As the die of the ejection portion, a die having an inner surface of the ejection hole and the vicinity of the outlet of the ejection hole coated with polytetrafluoroethylene (ejection hole diameter 4 mm) was extruded, and the amount of the meyani-like substance mixed into the product pellet was measured. At this time, 30
Air at 0 ° C. was blown at the outlet of the discharge hole at 30 Nl / min and 90 m / sec.

The coating process was carried out as in Example 1. The results are shown in Table 1. Comparative Examples 1 to 2 Examples 1 to 2 using a tool steel die without any coating
Extrusion was carried out in the same formulation as in 2, and the amount of the meyani-like substance mixed in the product pellets was specified. The results are shown in Table 1.

[0018] As is clear from Table 1, by coating the die with polytetrafluoroethylene, there was no contamination of the product in the form of shavings.

[0019]

As described above, in the die used in the discharge part of an extruder, a kneader, a polymerization can or the like in the manufacturing process of the molding resin composition, the inner surface of the discharge hole and the vicinity of the discharge hole outlet are made of fluorine. By coating with a resin, it is possible to obtain an effect of significantly reducing the contamination of the product of the messy product into the product. Furthermore, by blowing a gas such as air near the outlet of the discharge hole, it is possible to easily remove the dust-like substance generated at the discharge hole, and prevent the dust-like substance from mixing into the product. It is possible to prevent the product value of the product from deteriorating.

[Brief description of drawings]

FIG. 1 is a front view (discharging side) of a die of the present invention.

FIG. 2 is a rear view (extruder side) of the die of the present invention.

FIG. 3 is a sectional view of a die of the present invention.

FIG. 4 is a view showing an outline of an extruder equipped with a die of the present invention and a discharge state of a gut.

[Explanation of symbols]

1 Mouth 2 Discharge hole 3 Discharge hole inner surface 4 Near the discharge hole outlet covered with fluororesin 5 Extruder body 6 Polymer gut 7 Cooling bath 8 Gut cooling water

Claims (1)

[Claims] 1. A die used for an ejection part when ejecting a molten molding resin composition in a gut form, wherein the inner surface of the ejection hole of the die and the vicinity of the outlet of the ejection hole are coated with a fluororesin. A die for producing a characteristic resin composition for molding.