JPH10273810A - Melt-extruder for producing synthetic fiber and melt-extrusion fiber-forming process - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and stably form a layer coating the surfaces of the parts to interrupt the contact of the molten polymer with the surfaces in a melt- extrusion spinning machine and satisfactorily inhibit the gelation and deterioration caused by the direct contact between the melt-extrusion spinning machine and the molten polymer. SOLUTION: In a melt-extrusion spinning machine for synthetic fibers, the surfaces of the spinning machine are coated with a layer comprising oxides, nitrides or carbides of any metal selected from among Si, Ti, Zr, Al, W, B, Ta and Ge. SiO2 , TiO2 , ZrO2 and Al2 O3 are preferred as the coating layer. As parts in the melt-spinning machine to be coated with the metal compound, are cited the inner walls of the spinneret and/or the filtration material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a melt spinning apparatus and method for synthetic fibers. In particular, the present invention relates to improvement of an inner surface material of a spinning device used for melt spinning.

[0002]

2. Description of the Related Art Synthetic fibers such as polyamide fibers and polyester fibers are generally produced by a melt spinning method. Synthetic fibers obtained by the melt spinning method have excellent mechanical and chemical properties, and are therefore widely used for clothing and industrial materials.

In general, a spin pack is used for spinning a molten polymer. The molten polymer supplied to the spin pack through the pipe is spun from the outlet of the die after the flow path is widened in the spin pack and, if necessary, filtered. As a material of components such as a widening plate, a pressure plate, a base plate and the like constituting a spinning pack, stainless steel excellent in balance of strength, corrosion resistance, workability, price, and the like is generally used. Particle-based filter media such as glass beads, alumina-based particles, and stainless-based particles, or plate-shaped filter media mainly made of stainless steel wire mesh or metal fiber nonwoven fabric are used alone or in combination.

[0004] The stainless steel material used as a pack component or a filter material is a well-balanced material having many advantages as described above, which is difficult to replace with other materials.
As described in US Pat. No. 29732, the gelation of these polymers is promoted catalytically, especially by contact with molten polyester or polyamide.

[0005] In order to suppress gelation of a polymer due to contact with stainless steel, Japanese Patent Publication No. 53-29732 proposes to use an alloy having a high chromium content as a material of a metal filter medium having a particularly large contact area. Have been. However, as described in the publication, the alloy having a high chromium content has a small degree of promotion of gelation of the polymer as compared with stainless steel, but the gelation is also promoted by contact with the polymer in comparison with glass. Furthermore, the use of a high chromium alloy, which is more expensive than stainless steel, for a filter medium that is basically used disposably has a problem in industrial practice.

[0006] Silica sand, crow beads, alumina-based particles, etc., which are generally used as a filter medium with a material other than stainless steel, all have catalytic gelation-promoting action of a polymer such as stainless steel. However, as described in Japanese Patent Publication No. 5-32485, there are many fine irregularities on the surface, and such irregularities become active points in a high temperature state, and the molten polymer deteriorates particularly at the start of spinning. Not only deteriorates the spinnability, but also adversely affects the strength and elongation of the resulting fiber and the color tone after dyeing.

To solve these problems, Japanese Patent Publication No. 5-3
Japanese Patent Publication No. 2485 and Japanese Patent Publication No. 5-32486 describe a method of forming a silicone cured film on the surface of granular filter media particles and covering the irregularities on the particle surfaces to suppress polymer deterioration due to contact with the filter media. ing. Although this method is effective in suppressing polymer deterioration at the beginning of spinning, the silicone resin used is an organic silicone resin represented by methyl hydrogen polysiloxane, and the organic side which does not contribute to the siloxane bond such as a methyl group is used. Crosslinking density is low due to the large number of chains (substantially the same as the number of silicon atoms in the main chain), and there remains a problem in heat resistance during long-term use. In some parts, the organic silicone resin itself is deteriorated, so that it is not a preferable method. In addition, when an organic silicone resin treatment is applied to the filter medium, it is necessary to heat and filter the organic silicone resin-coated filter medium before assembling the spinning pack in order to prevent the filter medium from adhering and blocking. However, when the heat-crosslinking is performed on the filter medium or the pack parts, the number of steps increases, and furthermore, it takes a long time to cool down for assembling work after heating, and the workability deteriorates.

[0008]

As described above, in the melt spinning apparatus, contact between the molten polymer and an apparatus member or member made of stainless steel is not preferable in that gelation or deterioration of the polymer is promoted. However, the conventional means for shutting off the molten polymer and the component parts of the apparatus have advantages and disadvantages, so that a simpler and more stable means has been required for industrial implementation.

Therefore, the present invention solves the problems of the prior art, can easily and stably coat the inner surface of the apparatus, cuts off the contact between the molten polymer and the inner surface of the spinning apparatus, and allows the spinning apparatus and the molten polymer to be coated. It is a main object of the present invention to provide a melt spinning apparatus and a melt spinning method capable of sufficiently suppressing gelation and deterioration of a polymer due to contact with a melt.

[0010]

SUMMARY OF THE INVENTION The object of the present invention is to provide any one of Si, Ti, Zr, Al, W, B, Ta and Ge on a surface of a device portion of a synthetic fiber melt spinning device which comes into contact with a molten polymer. This has been achieved by forming a coating made of such a metal oxide, nitride or carbide. That is, the coating made of such specific inorganic compounds cuts off the contact between the spinning device member and the molten polymer,
The reaction on the contact surface between the spinning device member and the molten polymer can be extremely stably and easily suppressed, and gelation and deterioration of the polymer can be suppressed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

According to the present invention, the coating formed on the portion in direct contact with the molten polymer in the spinning device is made of Si, Ti, Zr, A
Since it is composed of an oxide, nitride or carbide of any one of l, W, B, Ta and Ge (hereinafter collectively referred to as inorganic compounds), it is electrochemically stable and usually melt-spun Is thermally stable for a long period of time even at a temperature of about 350 ° C. at the maximum. Specific examples include SiO ₂ , TiO ₂ , ZrO ₂ , Al ₂ O ₃ , S
iC, TiN, TiCN, TiC and the like. Among them, oxides such as SiO ₂ , TiO ₂ , ZrO ₂ , and Al ₂ O ₃ are preferable. These compounds may be used alone, or may be formed as a film in a mixture of two or more types, and even if the film has a uniform structure, a plurality of layers having different compositions in the thickness direction. May be used.

Although the same film-forming substance may be used for the film treatment of each part of the spinning apparatus, the film-forming substance, the film thickness and the like may be changed depending on the parts to be processed and the shape of the filter medium. May be changed.

The thickness of the film is not particularly limited, but is preferably 0.01 to 20 μm, and more preferably 0.02 to 10 μm. If the film thickness is smaller than 0.01 μm, it is difficult to form a uniform film, and the insulation between the pack member metal and the molten polymer is partially insufficient, so that the desired effect cannot be obtained. Conversely, if the film thickness is larger than 20 μm, it is not preferable because cracks and peeling are apt to occur in the treated film due to the difference in thermal expansion coefficient between the treated film and the base metal.

In the present invention, a spinning device refers to a series of devices from melting, measuring, filtering, and discharging a polyamide supplied in the form of chips into a molten yarn, and specifically, a screw type or a pressure melter type. It consists of a melting device, a measuring pump, a spinning pack, a filter medium, and a piping section connecting them. The spinning pack is for widening the flow path of the molten polymer supplied from the pipe, filtering if necessary, and uniformly discharging from the base plate, such as a widening plate, a base plate, a pressure plate, a housing, and the like. Consists of spin pack components. As the filter medium, a granular filter medium such as a sand or a glass bead or a flat filter medium such as a wire mesh or a metal nonwoven fabric is used alone or in combination. As a method of filtration, a filter medium may be placed on a pressure plate or a die, assembled into a spin pack together with spin pack components, or performed in the spin pack, or performed in a pipe from a melting device to the spin pack. Or both in the spin pack and in the piping.

In the present invention, all the surfaces where the polymer is in contact with the components of the spinning device in a molten state can be targeted as the portion where the coating treatment is performed. That is, for example, when a screw-type melt extrusion device is used, a screw, a barrel, a metering pump, a piping section, a spin pack component, a filter medium, and the like are targeted.

It is preferable to carry out the coating treatment on all of them. However, the coating treatment is performed only on the wall surfaces of the parts in the pack having a complicated flow path and a low flow rate, or the gelation or the degraded matter having a large surface area is easily generated. The coating treatment of only the filter media, which causes an increase in filtration pressure due to the fluoride, has a great effect on spinning, elongation and the quality of the synthetic fiber obtained. By doing so, a greater effect can be obtained.

As a method for forming these coatings on the portion of the spinning device which comes into contact with the polymer, the spinning device component is immersed in a liquid containing the coating product or the spinning device component contains the coating forming product. Examples include dipping or coating methods, such as drying after applying a liquid, and vacuum evaporation methods and CVD methods.They can be widely applied to the shape of the spinning device parts and filter media to be processed, and processing is simple and inexpensive. For this reason, a dipping or coating method is preferred.

From the viewpoint of being suitable for dipping or coating, the film-forming materials are SiO ₂ and TiO.
₂ , ZrO ₂ and Al ₂ O ₃ are preferred. As a film-forming substance for forming these films from a solution, for example, polysiloxane hydroxide can be used for forming an SiO ₂ film. Although a part of the hydroxyl group of the hydroxylated polysiloxane used for improving the handleability of the hydroxylated polysiloxane solution and the adhesiveness of the formed film may be modified with an alkyl group, etc. The degree of modification by an alkyl group or the like must be such that the heat resistance of the obtained film is not impaired.

Examples of the film-forming material for forming the TiO ₂ , ZrO ₂ , and Al ₂ O ₃ films include, for example, Ti, Z, such as tetrabutyl titanate, tetraisopropyl titanate, zirconium butoxide, and zirconium n-propoxide.
r, metal alcoholate of Al or its oligomer, or titanium tetraacetylacetonate, titanium ethyl acetoacetate, titanium octylene glycolate, titanium lactate, titanium triethanolamine, zirconium acetylacetonate, zirconium butoxyacetylacetonate, zirconyl Metal chelates such as acetate and aluminum acetylacetonate or oligomers thereof are mentioned. Dipping and coating can be performed using an aqueous solution or a non-aqueous solution of these substances. Among them, SiO ₂ is particularly preferable as a film forming product that easily forms a uniform film.

In general, a film-forming inorganic substance capable of forming a film by a dipping method or a coating method is easily cross-linked and cured by heating after application of a solution or by acting with a denaturing catalyst. For this reason, even in a state where only drying is performed at room temperature, stickiness is small, and it is possible to assemble the spinning apparatus without particularly performing heat crosslinking.
Also in this case, since the spinning device is preheated before the polymer is discharged, the crosslinking and curing proceeds during the preheating and temperature rising, and a stable and strong film is formed by the crosslinking and curing.

Further, when forming a film in the present invention, for example, when forming a film using SiO ₂ , methyltrimethoxysilane, dimethyldimethoxysilane or the like is mixed, and the cross-link density decreases heat resistance and stability. It may be adjusted in a range that does not exist.

The film forming treatment may be performed each time the spinning device parts are dismantled and washed, or if the film remains stable after dismantling and washing, the film forming treatment is not performed each time and the film can be used repeatedly. Good.

The spinning device parts and the filter medium which have been subjected to the coating treatment can be handled in the same manner as the conventional spinning apparatus parts and the filter medium. Therefore, the spinning apparatus parts and the filter medium can be assembled by a usual method, preheated and then melt-spun.

The formation of the coating of the inorganic compound specified in the present invention makes it possible to substantially isolate the contact between the polymer in the molten state and the surface of the spinning device component made of metal. This makes it possible to suppress the degradation and gelation of the polymer, which had conventionally occurred at the contact interface between the molten polymer and the metal, and as a result, the deterioration of the spinnability due to the incorporation of the deteriorated or gelled product into the product And quality degradation can be greatly reduced.

The melt-spinning apparatus and method of the present invention include nylon 6, nylon 66, nylon 46, nylon 4, nylon 11, nylon 12, nylon 610, and nylon 61.
Aliphatic polyamides such as No. 2; aromatic polyamides such as xylylenediamine polyamide; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polyolefins; and thermoplastic synthetic polymers represented by polyalkylenes or the like. It can be applied when melt-spinning such copolymers and blends, and is particularly suitable for melt-spinning polymers that are relatively easily decomposed at high temperatures, such as polyamides and polyesters.

The melt spinning method of the present invention can be used for the production of multifilaments, monofilaments, staples, spunbonded nonwoven fabrics and the like comprising the above synthetic fibers. Further, the viscosity and spinning speed of the polymer used, the draw ratio after spinning, the drawn yarn fineness and the like are not particularly limited, and the synthetic fiber obtained by the present invention is suitably used for industrial material applications and clothing applications. You.

[0028]

The present invention will be specifically described below with reference to examples. In addition, the measuring method of the characteristic etc. described in this specification is as follows.

(1) Relative viscosity of sulfuric acid 2.5 g of a sample is dissolved in 25 cc of 98% sulfuric acid, and measured at 25 ° C. using an Ostwald viscometer.

(2) Intrinsic viscosity 8 g of a sample is dissolved in 100 ml of orthochlorophenol, and the solution viscosity (η) is measured at 25 ° C. using an Ostwald viscometer, and the intrinsic viscosity (IV) is calculated from the following equation. IV = 0.0242η + 0.2634

(3) Filtration pressure The pressure on the upstream side of the spinning pack and on the secondary side of the measuring pump is measured with a diaphragm type pressure gauge.

Example 1 A SiO ₂ solution having film-forming properties (“Ceramate C513” manufactured by Catalysis Kasei Co., Ltd.) was solidified with isopropyl alcohol (IPA) at a solid concentration of 1.5 wt%.
And coated on the contact surface with the molten polymer of all the components of the spinning pack (made of stainless steel) except the filter medium made of stainless steel non-woven fabric, and dried at room temperature. The surface was coated with SiO ₂ by immersing a filter material (15 μm cut) made of stainless steel nonwoven fabric in a solution obtained by diluting the same SiO ₂ solution with IPA to a solid content concentration of 0.5 wt% and drying at room temperature. A pack part and a filter medium were obtained.

The resulting spinning pack parts and the filter medium were assembled, heated at 300 ° C. for 24 hours in a preheater, attached to the spinning machine, and spun with nylon 6 fiber having a sulfuric acid relative viscosity of 3.8 under the conditions shown in Table 1. Was.

Table 2 shows the initial filtration pressure, the filtration pressure on the 7th day from the start of use, and the frequency of occurrence of yarn breakage.

By using a pack component and a filter medium whose surfaces were coated with SiO ₂ , a rise in filtration pressure during use was small, and stable spinning with little thread breakage could be performed. [Example 2] A filter medium (15 μm
Example 1 except that no coating treatment was performed on the cut)
Spinning was carried out in the same manner as described above.

Table 2 shows the initial filtration pressure, the filtration pressure on the 7th day from the start of use, and the frequency of occurrence of yarn breakage.

By using a pack part whose surface was coated with SiO ₂ , a rise in filtration pressure during use was small, and stable spinning with little thread breakage could be performed.

[Example 3] Spinning was performed in the same manner as in Example 1 except that a coating treatment was applied to a filter medium (15 μm cut) made of a stainless steel non-woven fabric, and no coating treatment was applied to the other spinning pack parts. went.

Table 2 shows the initial filtration pressure, the filtration pressure on the 7th day from the start of use, and the frequency of occurrence of yarn breakage.

By using a pack part whose surface was coated with SiO ₂ , the rise of the filtration pressure during use was small, and stable spinning with little thread breakage could be performed.

Example 4 A TiO ₂ solution having film-forming properties (Atron NTi-500 manufactured by Nippon Soda Co., Ltd.) was diluted with isopropyl alcohol (IPA) to a solid concentration of 3% by weight, and all the spinning packs except the filter medium were removed. The product (made of stainless steel) was applied to the contact surface with the molten polymer and dried at room temperature. Filter media made of stainless steel non-woven fabric (20 μm cut)
The same TiO ₂ solution as above was treated with IPA to a solid content concentration of 1 wt.
% And dried at room temperature to obtain a pack part and a filter medium whose surfaces were coated with TiO ₂ .

The resulting spinning pack parts and the filter medium were assembled, heated at 300 ° C. for 24 hours in a preheater, attached to a spinning machine, and spun into polyethylene terephthalate fiber having an intrinsic viscosity of 1.2 under the conditions shown in Table 1. .

Table 2 shows the initial filtration pressure, the filtration pressure on the 7th day from the start of use, and the frequency of occurrence of yarn breakage.

By using a pack component and a filter medium whose surfaces were coated with TiO ₂ , a stable spinning with a small increase in filtration pressure during use and little breakage of yarn could be performed. [Example 5] A filter medium (20 μm
Cut) was immersed in a solution obtained by diluting the same SiO ₂ solution as in Example 1 with IPA to a solid concentration of 0.5 wt%, and then dried at normal temperature to obtain a filter medium coated with SiO ₂ on the surface. Spinning was performed under the same conditions as in Example 4 using the obtained filter medium and the same pack parts as those used in Example 4 except that the coating treatment was not performed.

Table 2 shows the initial filtration pressure, the filtration pressure on the 7th day from the start of use, and the frequency of occurrence of yarn breakage.

By using a filter medium whose surface was coated with SiO ₂ , a stable spinning with a small increase in filtration pressure during use and little breakage of yarn could be performed.

Comparative Example 1 A pack was assembled using the same pack parts as in Example 1 except that no surface treatment was performed, and a filter medium made of stainless steel nonwoven fabric, and heated at 300 ° C. for 24 hours in a preheater. Attached to a spinning machine, spinning of nylon 6 fiber having a relative viscosity of 3.8 in Example 1 was carried out under the same conditions as in Table 1 as in Example 1.

Table 2 shows the initial filtration pressure, the filtration pressure on the 7th day of use, and the frequency of yarn breakage.

In spinning using a pack component and a filter medium whose surface is not coated, the increase in filtration pressure with use time is larger than that in the case of coating, and the frequency of yarn breakage during spinning. Was also big.

Comparative Example 2 A pack was assembled using the same pack parts as in Example 4 except that no surface treatment was performed and a filter medium made of stainless steel nonwoven fabric, and heated to 300 ° C. for 24 hours in a preheater. The sample was attached to a spinning machine, and spinning of the same polyethylene terephthalate fiber having an intrinsic viscosity of 1.2 as in Example 4 was performed under the conditions shown in Table 1.

Table 2 shows the initial filtration pressure, the filtration pressure on the 7th day of use, and the frequency of yarn breakage.

In spinning using a pack component and a filter medium whose surface is not coated, the increase in filtration pressure with the use time is larger than in the case of coating, and the frequency of yarn breakage during spinning. Was also big.

[0053]

Table 1 Examples 1 to 3 Examples 4 and 5 And Comparative Example 1 and Comparative Example 2 Number of filaments (-) 144 196 Drawing yarn fineness (d) 840 1000 Spinning pack temperature (° C) 285 300 Heating hood length (cm) 30 30 Heating hood temperature (° C) 300 300 First roller Temperature (° C) No heating 70 ° Speed (m / min) 500 600 Second roller temperature (° C) 50 95 ° Speed (m / min) 5150 620 Third roller temperature (° C) 170 110 ° Speed (m / min) 1850 2200 4th roller temperature (° C) 200 220 〃 Speed (m / min) 2553 3300 5th roller temperature (° C) 130 Non-heating 速度 Speed (m / min) 2501 3200

[0054]

[Table 2]

[0055]

According to the apparatus and method of the present invention, it is possible to suppress the formation of a gelled substance and the deterioration of the polymer due to the contact between the metal and the molten polymer in the spinning apparatus, and as a result, the increase in the filtration pressure during use. In addition, yarn breakage can be greatly reduced. This makes it possible to stably obtain high-quality and high-quality fibers.

Claims (5)

[Claims] 1. A coating made of an oxide, nitride or carbide of a metal selected from the group consisting of Si, Ti, Zr, Al, W, B, Ta and Ge on a surface of an apparatus portion in contact with a molten polymer. A melt-spinning apparatus for synthetic fibers, wherein the apparatus is formed. 2. The coating is made of SiO ₂ , TiO ₂ , ZrO.
_2, Al ₂ O ₃ for synthetic fibers melt spinning apparatus according to claim 1, characterized in that it consists of at least one compound selected from the group consisting of. 3. The melt-spinning apparatus for synthetic fibers according to claim 1, wherein the portion of the device on which the coating is formed is an inner wall portion of a spin pack and / or a filter medium. 4. The method according to claim 1, wherein the polymer is melt-spun.
A melt spinning method, comprising using the melt spinning apparatus according to the above. 5. The method according to claim 4, wherein the polymer is a thermoplastic polyamide and / or a thermoplastic polyester.