JP7359596B2 - Method for manufacturing resin composition, method for manufacturing resin molded article - Google Patents

Description

The present invention relates to a method for producing a resin composition and a method for producing a resin molded article.

Liquid crystal polymers have good moldability, high heat resistance and strength, and excellent insulation properties, so they can be used to mold electrical/electronic parts and optical parts such as relays, coil bobbins, and lens holders. applied to the material.
In liquid crystal polymers, molecular chains tend to be oriented in the flow direction during molding, and anisotropy in mold shrinkage rate and mechanical properties tends to occur between the flow direction and the direction perpendicular to the flow direction. Therefore, in order to reduce the above-mentioned anisotropy, resin compositions in which fillers of various shapes are used in combination with a liquid crystal polymer are used as molding materials.

For example, when blending a fibrous filler into a liquid crystal polymer, it is desirable to control the average fiber length of the fibrous filler in order to obtain desired fluidity, moldability, and strength of the molded product.
On the other hand, Patent Document 1 discloses a method for producing a resin composition including a step of melt-kneading and extruding a resin and a fibrous filler using an extruder, which includes a cylinder, a screw, a main feed port, and a side Using the extruder equipped with a feed port, a portion of the resin and a portion of the fibrous filler having a weight average fiber length of 1 mm or more are supplied from the main feed port of the extruder. However, a method has been proposed in which the remaining amount of the resin and the remaining amount of the fibrous filler having a weight average fiber length of 1 mm or more are supplied from the side feed port of the extruder.
According to the manufacturing method described in Patent Document 1, it is said that the number average fiber length of the fibrous filler in the resin composition can be controlled to 100 to 220 μm, and the weight average fiber length can be controlled to 150 to 350 μm.

Japanese Patent Application Publication No. 2013-71281

In resin compositions that are molding materials for electrical/electronic parts and optical parts, there is a demand for short fibers of fibrous fillers depending on their uses.
In order to make the fibrous filler into short fibers, it is generally possible to strengthen the kneading of the resin and the fibrous filler using an extruder. However, in the conventional method of strengthening the kneading of resin and fibrous filler, there is a problem in that the screw provided in the extruder is abraded.

The present invention has been made in view of the above-mentioned circumstances, and is an object of the present invention, which suppresses the wear of the screw provided in the extruder and further improves the shortening of the fibrous filler contained in the resin composition. An object of the present invention is to provide a method for producing a resin composition and a method for producing a resin molded article.

In order to solve the above problems, the present invention employs the following configuration.

One aspect of the present invention is a method for producing a resin composition, which includes a step of melt-kneading a resin (A) and a fibrous filler (B) using an extruder, the extruder including a cylinder, a screw disposed within the cylinder; a main feed port provided in the cylinder; an upstream side feed port provided rearward in the extrusion direction from the main feed port of the cylinder; and the upstream side of the cylinder. a downstream side feed port provided rearward in the extrusion direction from the feed port, the resin (A) is fed from the main feed port, the upstream side feed port, and the downstream side feed port; The fibrous filler (B) is fed at least from the upstream side feed port, and the amount of the resin (A) fed from the downstream side feed port is equal to the amount of the fibers fed from the downstream side feed port. This is a method for producing a resin composition, characterized in that the amount of filler (B) is larger than that of filler (B).

In the method for producing a resin composition according to one aspect of the present invention, the length-weighted average fiber length of the fibrous filler (B) in the resin composition is preferably 30 to 140 μm.

In the method for producing a resin composition according to one aspect of the present invention, the resin (A) and the fibrous filler (B) are added from the upstream side feed port to 100% by mass of the total amount of the resin (A) and the fibrous filler (B). It is preferable that the amount of the resin (A) added is 1 to 20% by mass, and the amount of the resin (A) introduced from the downstream side feed port is 5 to 45% by mass.

In the method for producing a resin composition according to one aspect of the present invention, the mass ratio of the content of the resin (A) to the content of the fibrous filler (B) in the resin composition is 75:25 to 75:25. Preferably, the ratio is 50:50.

In the method for manufacturing a resin composition according to one aspect of the present invention, the resin (A) is preferably a liquid crystal polymer.
In the method for producing a resin composition according to one aspect of the present invention, the fibrous filler (B) is preferably at least one type selected from the group consisting of glass fibers and carbon fibers.

Further, one aspect of the present invention is a method for manufacturing a resin molded article, which includes a step of molding a resin composition obtained by the method for manufacturing a resin composition described above.

According to one aspect of the present invention, there is provided a method for producing a resin composition in which wear of a screw included in an extruder is suppressed and fibrous filler contained in the resin composition is made into shorter fibers, and a resin composition. A method for manufacturing a molded body can be provided.

It is a schematic sectional view showing an example of an extruder used in the manufacturing method of the resin composition of this embodiment.

(Method for manufacturing resin composition)
The method for producing a resin composition of the present embodiment includes a step of melt-kneading a resin (A) and a fibrous filler (B) using an extruder.

<Extruder>
The manufacturing method of this embodiment includes a cylinder, a screw disposed in the cylinder, a main feed port provided in the cylinder, and an upstream side provided rearward in the extrusion direction from the main feed port of the cylinder. An extruder is used that includes a feed port and a downstream side feed port provided rearward in the extrusion direction from the upstream side feed port of the cylinder.

FIG. 1 is a schematic cross-sectional view showing an example of an extruder used in the method for producing a resin composition of this embodiment.

The extruder 100 shown in FIG. 1 includes a motor 11 housed in a motor box 11a, a cylinder 12 provided adjacent to the motor box 11a, and a screw 13 arranged inside the cylinder 12 and connected to the motor 11. , is equipped with. The extruder 100 shown in FIG. 1 is a twin-screw extruder in which two screws 13 are inserted into a cylinder 12.

The cylinder 12 includes a main feed port 15, an upstream side feed port 17 provided rearward (downstream) in the extrusion direction from the main feed port 15, and a downstream side feed port 17 provided rearward in the extrusion direction from the upstream side feed port 17. A side feed port 19 is provided. The cylinder 12 also includes a first vent portion 14 between the upstream side feed port 17 and the downstream side feed port 19, and a second vent portion 16 located rearward (downstream side) in the extrusion direction from the downstream side feed port 19. It is equipped with Further, the cylinder 12 is provided with a discharge die 18 at the end opposite to the motor 11.
That is, the cylinder 12 is provided with a main feed port 15 at the most upstream position (on the motor box 11 side), and from the main feed port 15 toward the downstream side (backward in the extrusion direction: discharge die 18 side), A feed port 17, a first vent portion 14, a downstream side feed port 19, and a second vent portion 16 are provided in this order. A discharge die 18 is provided at the downstream end of the cylinder 12 . The discharge die 18 has a nozzle hole 18a that communicates with the cylinder 12.

The main feed port 15, the upstream side feed port 17, and the downstream side feed port 19 each have a hopper connected to the inside of the cylinder 12, and a supply device that supplies a constant mass or constant volume of raw material components. There is. The feeding method of the feeding device includes, for example, a belt type, a screw type, a vibration type, and a table type.
The above-mentioned "raw material components" refer to the resin (A), the fibrous filler (B), and other components used as necessary.

The screw 13 includes a conveying section 20 for conveying the resin composition (a mixture of resin (A) and fibrous filler (B)). The screw 13 also includes a first kneading section 21 for plasticizing and kneading the resin composition between the main feed port 15 and the upstream side feed port 17. A second kneading section 22 is provided between the vent section 14 for plasticizing and kneading the resin composition, and a second kneading section 22 is provided between the downstream side feed port 19 and the second vent section 16 for kneading the resin composition. The third kneading section 23 is provided to perform kneading.

Such a screw 13 is constructed by appropriately combining screw elements.
The conveyance section 20 is composed of forward flight (full flight) screw elements, and the first kneading section 21, second kneading section 22, and third kneading section 23 are composed of full flight, reverse flight, seal ring, forward kneading disk, and neutral. It is generally constructed by combining screw elements such as kneading disks and reverse kneading disks.

The elements of the first kneading section 21 and the second kneading section 22 include an element in which kneading disks are stacked one on top of the other with a phase angle greater than 0 degrees and less than 90 degrees, and a neutral kneading element. It is preferable to use a configuration in which the kneading disks are stacked at a phase angle of 90 degrees.
Further, it is preferable to use a neutral kneading element in the third kneading section 23.

The diameter of the screw 13 is preferably 60 mm or less, more preferably 58 mm or less.
Further, the ratio (L/D) of the total length (L) to the total width (D) of the cylinder 12 is preferably 50 or more, and more preferably 60 or more.
Since the diameter of the screw 13 is equal to or greater than the lower limit value, and L/D is equal to or greater than the lower limit value, sufficient kneading can be performed.

By reducing the pressure in the vent portion of the cylinder 12, the inside of the cylinder 12 can be degassed under reduced pressure. Further, the vent portion may be used simply for the purpose of releasing the decomposed gas in the cylinder 12 to the atmosphere.
In the extruder 100 shown in FIG. 1, the first vent section 14 and the second vent section 16 for discharging volatile components (decomposition gas, etc.) generated within the cylinder 12 can sufficiently perform deaeration.
The first vent section 14 and the second vent section 16 may be of an open vent type open to the atmosphere, or may be connected to a water ring pump, rotary pump, oil diffusion pump, turbo pump, etc. to maintain a vacuum. A vacuum vent system may also be used.

The opening length of each of the first vent part 14 and the second vent part 16 is preferably 0.5 to 5 times the diameter of the screw 13. The opening width of each of the first vent part 14 and the second vent part 16 is preferably 0.3 to 1.5 times the diameter of the screw 13.
When the opening length and opening width of the vent part are within this range, it is possible to prevent foreign matter from entering the vent part and vent up (melted resin rising from the vent part) while ensuring sufficient deaeration effect. I can do it.

<Resin (A)>
Examples of the resin (A) used in the method for producing the resin composition of the present embodiment include liquid crystal polymers, polyphenylene sulfide, polyether sulfone, polyamide, polyimide, etc., with liquid crystal polymers being preferred, and liquid crystal polyesters being particularly preferred. .

The liquid crystal polyester that can be used in the manufacturing method of this embodiment is a liquid crystal polyester that exhibits liquid crystallinity in a molten state, and preferably melts at a temperature of 450° C. or lower. Note that the liquid crystal polyester may be a liquid crystal polyester amide, a liquid crystal polyester ether, a liquid crystal polyester carbonate, or a liquid crystal polyester imide.
The liquid crystal polyester is preferably a wholly aromatic liquid crystal polyester using only an aromatic compound as a raw material monomer.

A typical example of liquid crystal polyester is
(I) Polymerized (polycondensed) of aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, and at least one compound selected from the group consisting of aromatic diol, aromatic hydroxyamine, and aromatic diamine. thing,
(II) one obtained by polymerizing multiple types of aromatic hydroxycarboxylic acids,
(III) A product obtained by polymerizing an aromatic dicarboxylic acid and at least one compound selected from the group consisting of an aromatic diol, an aromatic hydroxyamine, and an aromatic diamine;
(IV) Examples include those obtained by polymerizing polyester such as polyethylene terephthalate and aromatic hydroxycarboxylic acid.
Here, aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, aromatic diol, aromatic hydroxyamine, and aromatic diamine are each independently replaced with a part or all of them by their polymerizable derivatives. Good too.

Examples of polymerizable derivatives of compounds having a carboxyl group such as aromatic hydroxycarboxylic acids and aromatic dicarboxylic acids include derivatives obtained by converting a carboxyl group into an alkoxycarbonyl group or an aryloxycarbonyl group (ester), carboxyl Examples include those obtained by converting a group into a haloformyl group (acid halides) and those obtained by converting a carboxy group into an acyloxycarbonyl group (acid anhydrides).
Examples of polymerizable derivatives of compounds having hydroxy groups such as aromatic hydroxycarboxylic acids, aromatic diols, and aromatic hydroxyamines include those obtained by acylating a hydroxy group to convert it into an acyloxyl group (acylated derivatives). ).
Examples of polymerizable derivatives of compounds having an amino group such as aromatic hydroxyamines and aromatic diamines include those obtained by acylating an amino group to convert it into an acylamino group (acylated product).

The liquid crystal polyester preferably has a repeating unit represented by the following general formula (1) (hereinafter sometimes referred to as "repeat unit (1)"), and the repeating unit (1) and the following general formula (2) A repeating unit represented by (hereinafter sometimes referred to as "repeat unit (2)") and a repeating unit represented by the following general formula (3) (hereinafter sometimes referred to as "repeat unit (3)"). It is more preferable to have the following.

(1) -O-Ar ¹ -CO-
(2) -CO-Ar ² -CO-
(3) -X-Ar ³ -Y-

(In the formula, Ar ¹ represents a phenylene group, a naphthylene group, or a biphenylylene group; Ar ² and Ar ³ are each independently a phenylene group, a naphthylene group, a biphenylylene group, or a group represented by the following general formula (4) represents; X and Y each independently represent an oxygen atom or an imino group (-NH-); one or more hydrogen atoms in Ar ¹ , Ar ² and Ar ³ each independently represent a halogen atom, (May be substituted with an alkyl group or an aryl group.)

(4) -Ar ⁴ -Z-Ar ⁵ -

(In the formula, Ar ⁴ and Ar ⁵ each independently represent a phenylene group or a naphthylene group; Z represents an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or an alkylidene group.)

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, Examples include n-heptyl group, 2-ethylhexyl group, n-octyl group, n-nonyl group, and n-decyl group, and the number of carbon atoms thereof is preferably 1 to 10.
Examples of the aryl group include phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 1-naphthyl group, and 2-naphthyl group, and the number of carbon atoms thereof is 6 to 20. is preferred.
When the hydrogen atoms are substituted with these groups, the number is preferably 2 or less, and 1 for each of the groups represented by Ar ¹ , Ar ² or Ar ³ . It is more preferable that it is below.

Examples of the alkylidene group include methylene group, ethylidene group, isopropylidene group, n-butylidene group, and 2-ethylhexylidene group, and preferably has 1 to 10 carbon atoms.

The repeating unit (1) is a repeating unit derived from a predetermined aromatic hydroxycarboxylic acid. As the repeating unit (1), one in which Ar ¹ is a p-phenylene group (a repeating unit derived from p-hydroxybenzoic acid), and one in which Ar ¹ is a 2,6-naphthylene group (6-hydroxy-2 - repeating units derived from naphthoic acid) are preferred.

The repeating unit (2) is a repeating unit derived from a predetermined aromatic dicarboxylic acid. As the repeating unit (2), Ar ² is a p-phenylene group (repeat unit derived from terephthalic acid), Ar ² is a m-phenylene group (repeat unit derived from isophthalic acid), Ar ² is a 2,6-naphthylene group (repeating unit derived from 2,6-naphthalene dicarboxylic acid), and Ar ² is a diphenyl ether-4,4'-diyl group (diphenyl ether-4,4'-diyl group). A repeating unit derived from 4,4'-dicarboxylic acid) is preferred.

The repeating unit (3) is a repeating unit derived from a predetermined aromatic diol, aromatic hydroxylamine, or aromatic diamine. As the repeating unit (3), Ar ³ is a p-phenylene group (a repeating unit derived from hydroquinone, p-aminophenol or p-phenylenediamine), and Ar ³ is a 4,4'-biphenylylene group. (repeating units derived from 4,4'-dihydroxybiphenyl, 4-amino-4'-hydroxybiphenyl or 4,4'-diaminobiphenyl) are preferred.

The content of repeating units (1) is calculated by dividing the total amount of all repeating units that make up the liquid crystal polyester (by dividing the mass of each repeating unit that makes up the liquid crystal polyester by the formula weight of each repeating unit). Calculate the equivalent amount (mol) and add up the total amount), preferably 30 mol% or more, more preferably 30 to 80 mol%, even more preferably 40 to 70 mol%, particularly preferably 45 to 65 mol%. It is mole%.
The content of the repeating unit (2) is preferably 35 mol% or less, more preferably 10 to 35 mol%, even more preferably 15 to 30 mol%, based on the total amount of all repeating units constituting the liquid crystal polyester. Particularly preferred is 17.5 to 27.5 mol%.
The content of the repeating unit (3) is preferably 35 mol% or less, more preferably 10 to 35 mol%, even more preferably 15 to 30 mol%, based on the total amount of all repeating units constituting the liquid crystal polyester. Particularly preferred is 17.5 to 27.5 mol%.
The higher the content of the repeating unit (1), the easier it is to improve melt fluidity, heat resistance, strength, and rigidity, but if it is too large, the melt temperature and melt viscosity tend to increase, and the temperature required for molding increases. easy.

The ratio between the content of repeating unit (2) and the content of repeating unit (3) is expressed as [content of repeating unit (2)]/[content of repeating unit (3)] (mol/mol). The ratio is preferably 0.9/1 to 1/0.9, more preferably 0.95/1 to 1/0.95, and even more preferably 0.98/1 to 1/0.98.

Note that the liquid crystal polyester may have two or more types of repeating units (1) to (3), each independently. Further, the liquid crystal polyester may have repeating units other than repeating units (1) to (3), but the content thereof is preferably 10 It is mol% or less, more preferably 5 mol% or less.

The liquid crystal polyester preferably has a repeating unit (3) in which X and Y are each an oxygen atom, that is, a repeating unit derived from a predetermined aromatic diol, and as a repeating unit (3), It is more preferable that X and Y each have only oxygen atoms. By doing so, the melt viscosity of the liquid crystal polyester tends to decrease.

Liquid crystalline polyester is preferably produced by melt polymerizing raw material monomers corresponding to the repeating units constituting it, and solid-phase polymerizing the obtained polymer (hereinafter sometimes referred to as "prepolymer"). . Thereby, a high molecular weight liquid crystal polyester having high heat resistance, strength, and rigidity can be manufactured with good operability.
Melt polymerization may be carried out in the presence of a catalyst, examples of which include metals such as magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, and antimony trioxide. and nitrogen-containing heterocyclic compounds such as 4-(dimethylamino)pyridine and 1-methylimidazole, and nitrogen-containing heterocyclic compounds are preferably used.

The liquid crystal polyester preferably has a flow initiation temperature of 270°C or higher, more preferably 270 to 400°C, and even more preferably 280 to 380°C. The higher the flow start temperature, the easier it is to improve heat resistance, strength, and rigidity, but if the flow start temperature is too high, the melt temperature and melt viscosity tend to increase, and the temperature required for molding tends to increase.

Note that the flow start temperature is also called flow temperature or flow temperature, and the liquid crystal polyester is heated at a rate of 4° C./min under a load of 9.8 MPa (100 kg/cm ² ) using a capillary rheometer. This is the temperature at which liquid crystalline polyester exhibits a viscosity of 4800 Pa·s (48000 poise) when it is melted and extruded through a nozzle with an inner diameter of 1 mm and a length of 10 mm, and is a guideline for the molecular weight of liquid crystal polyester (edited by Naoyuki Koide, " (See "Liquid Crystal Polymers - Synthesis, Molding, Applications," CMC Co., Ltd., June 5, 1987, p. 95).

<Fibrous filler (B)>
The fibrous filler (B) used in the method for producing a resin composition of this embodiment may be a fibrous inorganic filler or a fibrous organic filler.
Examples of fibrous inorganic fillers include glass fibers; carbon fibers such as bread-based carbon fibers and pitch-based carbon fibers; ceramic fibers such as silica fibers, alumina fibers, and silica-alumina fibers; metals such as stainless steel fibers. fiber; and basalt fiber. Furthermore, examples of the fibrous inorganic filler include whiskers such as potassium titanate whiskers, barium titanate whiskers, wollastonite whiskers, aluminum borate whiskers, silicon nitride whiskers, and silicon carbide whiskers.
Examples of fibrous organic fillers include polyester fibers and aramid fibers.
Considering the wear load on the equipment during molding and availability, the fibrous filler (B) is preferably a fibrous inorganic filler selected from the group consisting of glass fiber, carbon fiber, basalt fiber, and alumina fiber. At least one selected from the group consisting of , glass fiber, and carbon fiber is more preferable, and among these, glass fiber is even more preferable.

Furthermore, the fibrous filler (B) may be a mixture of two or more of the fillers described above. Moreover, the fibrous filler (B) may be a mixture of the fibrous filler and other fillers. The amount of fillers other than these is usually 0 to 100 parts by weight per 100 parts by weight of the resin composition.

In addition, the fibrous filler (B) further reduces the gas generated from the resin molded body obtained using the resin composition obtained by the manufacturing method of this embodiment, and improves the chemical stability of the resin molded body. A surface coating treatment may be applied from the viewpoint that the generated gas is less likely to contaminate surrounding members when the electrical/electronic equipment or optical equipment is assembled. Examples of the surface coating treatment include surface coating treatment using a coupling agent such as a titanium coupling agent, and surface coating treatment using various thermosetting resins and thermoplastic resins.
Further, the glass fiber serving as the fibrous filler (B) may be coated with epoxy, urethane, acrylic, or the like, or treated with a sizing agent.

The length weighted average fiber length of the fibrous filler (B) as a raw material component is preferably 1 mm or more, more preferably 1 mm or more and 10 mm or less, and still more preferably 2 mm or more and 10 mm or less.
The fibrous filler (B) as a raw material component is preferably chopped strands with uniform fiber length and no distribution in fiber length.

The average diameter of the fibrous filler (B) is preferably 3 to 15 μm.
When the average diameter of the fibrous filler (B) is less than 3 μm, the effect as a reinforcing material tends to be reduced. Moreover, when the average diameter of the fibrous filler (B) exceeds 15 μm, moldability tends to decrease and the surface appearance tends to deteriorate.
The fibrous filler (B) is preferably chopped strands having uniform lengths without any distribution.

Next, regarding the method for producing the resin composition of the present embodiment, the resin composition is produced by extruding the resin (A) and the fibrous filler (B) while melt-kneading them using the extruder 100 shown in FIG. The case of manufacturing will be explained.

[Melt-kneading process]
This embodiment includes a step of melt-kneading the resin (A) and the fibrous filler (B) using the extruder 100 (melt-kneading step).
Hereinafter, in the manufacturing method of this embodiment, resin (A) and fibrous filler (B) are put into an extruder, melt-kneaded, and the kneaded product is extruded to produce a pellet-shaped resin composition.

In the method for producing a resin composition of the present embodiment, the resin (A) is introduced through the main feed port 15, the upstream side feed port 17, and the downstream side feed port 19.
In addition, the fibrous filler (B) is introduced from at least the upstream side feed port 17. That is, the resin (A) and the fibrous filler (B) are introduced from the upstream side feed port 17.
Further, both of them are introduced so that the amount of the resin (A) introduced from the downstream side feed port 19 is larger than the amount of the fibrous filler (B) introduced from the downstream side feed port 19. .

In the manufacturing method of the present embodiment, the resin (A) and the fibrous filler (B) are inputted from the upstream side feed port 17 in an amount of 100% by mass of the total input amount of the resin (A) and the fibrous filler (B) to the extruder 100. The amount of resin (A) is preferably 1 to 20% by weight, more preferably 3 to 15% by weight, and even more preferably 10 to 15% by weight.
With respect to 100% by mass of the total amount of the resin (A) and the fibrous filler (B) input into the extruder 100, the amount of the resin (A) input from the downstream side feed port 19 is: It is preferably 5 to 45% by weight, more preferably 15 to 40% by weight, and even more preferably 20 to 35% by weight.
With respect to 100% by mass of the total amount of the resin (A) and the fibrous filler (B) input into the extruder 100, the amount of the resin (A) input from the main feed port 15 is 5 to 5%. It is preferably 35% by weight, more preferably 10 to 30% by weight, even more preferably 14 to 25% by weight.
If the amount of resin (A) input from each input port is at least the lower limit of the above-mentioned preferred range, the resin composition will have better fluidity and will be easier to mold. On the other hand, if it is below the upper limit of the above-mentioned preferable range, the reinforcing effect of the resin molded article obtained using the resin composition will be more likely to be enhanced.

The amount of the resin (A) introduced from the upstream side feed port 17 is preferably 3 to 35% by mass, and 5 to 30% by mass, based on 100% by mass of the total amount of resin (A) introduced. %, and even more preferably 5 to 24% by mass.
The amount of resin (A) introduced from the downstream side feed port 19 is preferably 30 to 70% by mass, and 35 to 65% by mass, based on 100% by mass of the total amount of resin (A) introduced. %, and even more preferably 40 to 65% by mass.
The amount of the resin (A) inputted from the main feed port 15 is preferably 15 to 50% by mass, and preferably 20 to 45% by mass, based on 100% by mass of the total amount of resin (A) input. It is more preferable that the amount is 20 to 40% by mass.

The amount of the fibrous filler (B) introduced from the upstream side feed port 17 is preferably 80% by mass or more, and 90% by mass or more based on 100% by mass of the total amount of the fibrous filler (B). It is more preferably at least 100% by mass, and may be at least 100% by mass.
The amount of the fibrous filler (B) inputted from the downstream side feed port 19 is preferably 0 to 15% by mass with respect to 100% by mass of the total input amount of the fibrous filler (B), It is more preferably 0 to 10% by mass, and even more preferably 0 to 5% by mass.
The amount of the fibrous filler (B) introduced from the main feed port 15 is preferably 0 to 15% by mass, and 0 to 15% by mass, based on 100% by mass of the total amount of fibrous filler (B). It is more preferably 10% by mass, and even more preferably 0 to 5% by mass.

The amount of fibrous filler (B) introduced from the upstream side feed port 17 is 100% by mass of the total amount of resin (A) and fibrous filler (B) introduced from the upstream side feed port 17. It is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 70 to 95% by mass, and particularly preferably 70 to 80% by mass.
If the amount of the fibrous filler (B) is at least the lower limit of the above-mentioned preferred range, the reinforcing effect of the resin molded article obtained using the resin composition will be more likely to be enhanced. On the other hand, if it is below the upper limit of the above-mentioned preferable range, wear of the screw 13 will be easily suppressed.

The amount of resin (A) introduced from the downstream side feed port 19 is based on 100% by mass of the total amount of resin (A) and fibrous filler (B) introduced from the downstream side feed port 19. The content is more than 50% by mass, preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, and may be 100% by mass.
When the amount of the resin (A) is at least the lower limit of the above-mentioned preferred range, the fibrous filler (B) can be made into shorter fibers.

As a method of charging the resin (A) and the fibrous filler (B) from the upstream side feed port 17, for example, a mixture of the resin (A) and the fibrous filler (B) mixed in advance is charged. Method: A method can be adopted in which the resin (A) and the fibrous filler (B) are used separately and these components are continuously fed simultaneously using two feeders.
Similarly, the above-described charging method may be used when charging the resin (A) and the fibrous filler (B) from the main feed port 15 and the downstream side feed port 19.

In the method for producing a resin composition of the present embodiment, it is preferable to perform kneading at a temperature in the cylinder 12 of the extruder 100 at which the resin (A) melts (in the range of 400°C to 330°C).

The discharge amount of the resin composition (mixture of resin (A) and fibrous filler (B)) from the discharge die 18 of the extruder 100 is preferably in the range of 200 kg/hr to 400 kg/hr. Further, the rotation speed of the screw 13 of the extruder 100 is preferably in the range of 100 rpm to 500 rpm.
Note that these manufacturing conditions are preferably adjusted so that the torque is 60% or more.

The strand of the composition extruded from the nozzle hole 18a of the discharge die 18 is cut and processed into pellets. For example, before cutting the strand, the strand may be solidified by air cooling or water cooling. As a cutter used for cutting, a cutter that is a combination of a rotating blade and a fixed blade is generally used.

Under the above manufacturing conditions, resin (A) and fibrous filler (B) are charged into extruder 100, melt-kneaded, and the kneaded product is extruded, thereby producing a pellet-shaped resin composition.
The length weighted average fiber length of the fibrous filler in the obtained resin composition is preferably 30 to 140 μm, more preferably 40 to 130 μm, even more preferably 50 to 125 μm, particularly preferably 50 to 120 μm. It is.
Further, the number average fiber length of the fibrous filler in the obtained resin composition is preferably 20 to 100 μm, more preferably 30 to 95 μm, and still more preferably 40 to 90 μm.
If the fiber length of the fibrous filler in the resin composition is at least the lower limit of the above-mentioned preferred range, the rigidity of the resin molded article obtained using the resin composition will be further increased. On the other hand, if it is below the upper limit of the above-mentioned preferable range, the fluidity of the resin composition will be further improved when molding a resin molded article using the resin composition. Moreover, the appearance of the surface of a resin molded article obtained using the resin composition becomes good, and dust generation is easily suppressed.
As described above, the fiber length of the fibrous filler in the resin composition changes (shortening) from the fiber length of the raw material component (fiber length of the fibrous filler (B)) by melt-kneading or the like.

[Method for measuring fiber length of fibrous filler]
The length weighted average fiber length and number average fiber length of the fibrous filler are directly determined from the external shape of the fibrous filler in the resin composition.
That is, it is determined by collecting 1.0 g of fibrous filler, dispersing it in methanol, observing the shape (length) of the fibrous filler using a fiber length measuring device, and calculating the average value. It is something.
In addition, when calculating the average value, the parameter is set to 4000 or more. Regarding each weight, the weight for each fiber length is calculated from the specific gravity of the fibrous filler, and the total weight of the sample used is used to calculate the average value.

In the method for producing a resin composition according to one aspect of the present invention, the mass ratio of the content of the resin (A) to the content of the fibrous filler (B) in the resin composition is 75:25 to 75:25. The ratio is preferably 50:50, more preferably 70:30 to 50:50, even more preferably 65:35 to 55:45.
If the ratio of the fibrous filler (B) in the resin composition is at least the lower limit of the above-mentioned preferred range, the reinforcing effect of the resin molded article obtained using the resin composition can be easily obtained, and the rigidity can be increased. It will be done. On the other hand, if the ratio of the fibrous filler (B) in the resin composition is below the upper limit of the above-mentioned preferred range, the resin composition will have good fluidity when molded using the resin composition, and Improves workability.

In the method for manufacturing a resin composition of the present embodiment described above, the cylinder 12 is provided with an upstream side feed port 17 and a downstream side feed port 19 in this order from the main feed port 15 toward the downstream side. An extruder 100 equipped with the following is used.
In addition, resin (A) is introduced through the main feed port 15, the upstream side feed port 17, and the downstream side feed port 19. The fibrous filler (B) is introduced from at least the upstream side feed port 17. That is, the resin (A) and the fibrous filler (B) are introduced from the upstream side feed port 17. Since the resin (A) and the fibrous filler (B) are added together, the load on the screw 13 is reduced. This suppresses wear on the screw 13.
Further, both of the resins (A) are introduced so that the amount of resin (A) introduced from the downstream side feed port 19 is larger than the amount of the fibrous filler (B) introduced from the downstream side feed port 19. Since more resin (A) than the fibrous filler (B) is fed from the downstream side feed port 19, pulverization of the fibrous filler (B) is promoted. Thereby, the fibrous filler (B) can be made into shorter fibers.
Therefore, according to the method for producing a resin composition of the present embodiment, wear of the screw included in the extruder is suppressed, and the fibrous filler contained in the resin composition can be made into shorter fibers.

According to the method for producing a resin composition of the present embodiment, even when the kneading of the resin and the fibrous filler is strengthened, the screw is less likely to wear out.
Further, according to the method for producing a resin composition of the present embodiment, it is possible to efficiently shorten the fibers to about 100 μm and improve productivity.

In the above-described method for producing a resin composition according to the present invention, the extruder that can be used is not limited to the extruder having the configuration shown in FIG. When an extruder is used, it may be one with a single thread or three threads rotating in the same direction, a parallel shaft type rotating in different directions, an oblique shaft type, or an incompletely interlocking type.
Furthermore, the extruder that can be used in the method for producing a resin composition according to the present invention is not limited to the extruder having the configuration shown in FIG. A fourth kneading section and a fifth kneading section may be further provided between the feed port 19 and the feed port 19. At this time, it is preferable to sufficiently control the cylinder temperature to suppress shear heat generation.

In addition, when the screw 13 further includes a kneading section at the rear (downstream side) in the extrusion direction of the third kneading section 23, a neutral kneading element is used in the kneading section located at the most downstream position, and the kneading section other than the most downstream kneading section It is preferable to use a neutral kneading element and an element in which kneading disks are stacked one on top of the other while being shifted so that the phase angle is larger than 0 and smaller than 90 degrees.

In addition, in the above-described embodiment, the resin (A) and the fibrous filler (B) were melt-kneaded using an extruder, and the kneaded product was extruded to produce a pellet-shaped resin composition. The shape of the resin composition is not limited, and the shape of the resin composition may be other than pellets.

Furthermore, in the above-described embodiments, the resin composition melt-kneaded using an extruder contains the resin (A) and the fibrous filler (B), but the present invention is limited to this example. First, one or more other components may be further blended into the resin composition that is melt-kneaded using an extruder. Other components may be introduced into the cylinder 12 from the main feed port 15, the upstream side feed port 17, or the downstream side feed port 19, as required.

Examples of the other components include additives such as antioxidants, heat stabilizers, ultraviolet absorbers, antistatic agents, surfactants, metering stabilizers, flame retardants, and colorants; resins other than liquid crystal polyester, etc. can be mentioned.
Resins other than liquid crystal polyester include polypropylene, polyamide, polyester other than liquid crystal polyester, polysulfone, polyphenylene sulfide, polyether ketone, polycarbonate, polyphenylene ether, polyether imide, and other thermoplastic resins other than liquid crystal polyester; phenol resin, epoxy resin , polyimide resin, cyanate resin, and other thermosetting resins.
The blending amount of the additive is preferably 0 to 5 parts by weight based on 100 parts by weight of the resin (A).
The blending amount of the resin other than the liquid crystal polyester is preferably 0 to 99 parts by weight based on 100 parts by weight of the resin (A).

(Method for manufacturing resin molded body)
The method for manufacturing a resin molded article according to the present embodiment includes a step of molding a resin composition obtained by the method for manufacturing a resin composition described above.

The method for molding the resin composition obtained by the manufacturing method of the embodiment described above is preferably a melt molding method.
Examples of the melt molding method include injection molding; extrusion molding methods such as T-die method and inflation method; compression molding method; blow molding method; vacuum molding method; press molding method, etc. Among them, injection molding method is particularly preferred. .

Various resin molded bodies can be obtained by molding using the method for manufacturing a resin molded body of this embodiment. That is, the resin molded body here is produced using the resin composition obtained by the manufacturing method of the embodiment described above, and includes, for example, electrical/electronic parts and optical parts.
Specifically, such resin molded bodies include connectors, sockets, relay parts (vehicle relays, signal relays, power relays, etc.), coil bobbins, optical pickups, resonators, printed wiring boards, circuit boards, semiconductor packages, computer-related parts, Semiconductor manufacturing process related parts such as camera lens barrels, optical sensor housings, compact camera module housings (packages and lens barrels), projector optical engine components, IC trays, wafer carriers; VTRs, televisions, irons, air conditioners, stereos, Parts for home appliances such as vacuum cleaners, refrigerators, rice cookers, and lighting equipment; Parts for lighting equipment such as lamp reflectors and lamp holders; Parts for audio products such as compact discs, laser discs (registered trademarks), and speakers; Ferrules for optical cables, and telephones. Examples include parts, facsimile parts, and communication equipment parts such as modems.

In addition, such resin molded products can be used for purposes other than those mentioned above, such as parts related to copying machines and printing machines such as separation claws and heater holders; mechanical parts such as impellers, fan gears, gears, bearings, motor parts and cases; and automobiles. Automotive parts such as mechanical parts, engine parts, parts inside the engine room, electrical parts, interior parts; Cooking utensils such as microwave cooking pots and heat-resistant tableware; Insulation and soundproofing materials for flooring and wall materials, beams , supporting materials such as pillars, building materials such as roofing materials, or materials for civil engineering and construction; parts for aircraft, spacecraft, and aerospace equipment; parts for radiation facilities such as nuclear reactors, parts for marine facilities, cleaning jigs, and parts for optical equipment. , valves, pipes, nozzles, filters, membranes, medical equipment parts and materials, sensor parts, sanitary equipment, sporting goods, leisure goods, etc.

The resin molded article obtained by the manufacturing method of this embodiment has excellent mechanical strength, heat resistance, and moldability because a resin composition (molding material) in which the fibrous filler is made into shorter fibers is applied. In addition, it also has dust resistance.

Hereinafter, the present invention will be explained in more detail with reference to specific examples. However, the present invention is not limited to the examples shown below.

[Flow starting temperature of liquid crystal polyester]
Using a flow tester ("CFT-500 model" manufactured by Shimadzu Corporation), about 2 g of liquid crystal polyester was filled into a cylinder equipped with a die having a nozzle with an inner diameter of 1 mm and a length of 10 mm. Next, under a load of 9.8 MPa (100 kg/cm ² ), while increasing the temperature at a rate of 4°C/min, the liquid crystal polyester is melted and extruded from the nozzle until the temperature shows a viscosity of 4800 Pa·s (48000 poise). (flow start temperature) was measured and defined as the flow start temperature of the liquid crystal polyester.

[Fiber length of glass fiber which is a raw material component]
The length weighted average fiber length and number average fiber length of the glass fibers, which are raw material components, are directly determined from the external shape of the glass fibers.
That is, 1.0 g of glass fiber was collected, dispersed in methanol, and the shape (length) of the glass fiber was observed using a fiber length measuring device ("PITA-3" manufactured by Seishin Enterprise Co., Ltd.). It was determined by calculating the average value.
In addition, in calculating the average value, the parameter was set to 4000 or more. Regarding each weight, the weight for each fiber length was calculated from the specific gravity of the glass fiber, and the total weight of the sample used was used to calculate the average value.

<Production method of liquid crystal polyester: LCP (1)>
994.5 g (7.2 mol) of p-hydroxybenzoic acid and 358.8 g (2.16 mol) of terephthalic acid were placed in a reactor equipped with a stirring device, a torque meter, a nitrogen gas inlet tube, a thermometer, and a reflux condenser. ), 39.9 g (0.24 mol) of isophthalic acid, 446.9 g (2.4 mol) of 4,4'-dihydroxybiphenyl, and 1347.6 g (13.2 mol) of acetic anhydride were added. After replacing the gas in the reactor with nitrogen gas, 0.18 g of 1-methylimidazole was added, and while stirring under a nitrogen gas flow, the temperature was raised from room temperature to 150°C over 30 minutes, and then at 150°C for 30 minutes. Refluxed.
Next, the temperature was raised from 150°C to 320°C over 2 hours and 50 minutes while distilling off by-produced acetic acid and unreacted acetic anhydride, and when an increase in torque was observed, the contents were removed from the reactor. It was taken out and cooled to room temperature to obtain a solid prepolymer.
Next, this prepolymer was pulverized using a pulverizer, and the temperature of the obtained pulverized product was raised from room temperature to 250°C over 1 hour under a nitrogen atmosphere, and then from 250°C to 295°C over 5 hours. , solid phase polymerization was carried out by holding at 295° C. for 3 hours.
The obtained solid phase polymer was cooled to room temperature to obtain a powdery liquid crystal polyester (LCP (1)). The flow initiation temperature of the obtained liquid crystal polyester (LCP (1)) was 360°C.

<Production method of liquid crystal polyester: LCP (2)>
994.5 g (7.2 mol) of p-hydroxybenzoic acid and 299.0 g (1.8 mol) of terephthalic acid were placed in a reactor equipped with a stirring device, a torque meter, a nitrogen gas inlet tube, a thermometer, and a reflux condenser. ), 99.7 g (0.6 mol) of isophthalic acid, 446.9 g (2.4 mol) of 4,4'-dihydroxybiphenyl, and 1347.6 g (13.2 mol) of acetic anhydride were added. After replacing the gas in the reactor with nitrogen gas, 0.18 g of 1-methylimidazole was added, and while stirring under a nitrogen gas flow, the temperature was raised from room temperature to 150°C over 30 minutes, and then at 150°C for 30 minutes. Refluxed.
Next, 2.4 g of 1-methylimidazole was added, and the temperature was raised from 150°C to 320°C over 2 hours and 50 minutes while distilling off by-produced acetic acid and unreacted acetic anhydride, and an increase in torque was observed. At that point, the contents were taken out from the reactor and cooled to room temperature to obtain a solid prepolymer.
Next, this prepolymer was pulverized using a pulverizer, and the temperature of the obtained pulverized product was raised from room temperature to 250°C over 1 hour under a nitrogen atmosphere, and then from 250°C to 295°C over 5 hours. , solid phase polymerization was carried out by holding at 295° C. for 3 hours.
The obtained solid phase polymer was cooled to room temperature to obtain a powdery liquid crystal polyester (LCP(2)). The flow initiation temperature of the obtained liquid crystal polyester (LCP (2)) was 327°C.

The raw material components used in this example are shown below.
・Resin (A)
Liquid crystal polyester (LCP(1))
Liquid crystal polyester (LCP(2))

・Fibrous filler (B)
GF: Glass fiber, trade name CS-3J-260S (manufactured by Nittobo Co., Ltd.); length-weighted average fiber length 3 mm.

<Method for manufacturing resin composition>
(Examples 1 to 10, Comparative Examples 1 to 8)
Using an extruder, the above resin (A) and fibrous filler (B) were melt-kneaded and pelletized to obtain a pellet-shaped resin composition. Specifically, the manufacturing method of each example was carried out as follows to obtain each resin composition.

As the resin (A), LCP (1) and LCP (2) were each used after being dried at 120° C. for 5 hours.
As the extruder, the same extruder as shown in FIG. 1 was used. Specifically, the mixture was melt-kneaded using a twin-screw extruder with a vacuum vent ("TEM-41SS" manufactured by Toshiba Machine Co., Ltd.) under the conditions of a cylinder temperature of 340°C and a screw rotation speed of 150 rpm while degassing with a vacuum vent. The extrusion rate was set to 300 kg/hr, and the product was discharged in the form of a strand through a circular nozzle (discharge port) with a diameter of 3 mm.
The raw material input method was to input the raw material components from the main feed port, upstream side feed port, and downstream side feed port, respectively, according to the blending ratio shown in Table 1. There was one shooter each at the main feed port, the upstream side feed port, and the downstream side feed port, and when feeding two types of raw material components, two feeders were used in combination to feed the raw material components at the same time.
Next, the discharged strand-like kneaded material was passed through a water bath at a water temperature of 30° C. for 1.5 seconds, and then pelletized to obtain a pellet-like resin composition.

<Evaluation>
Regarding the resin compositions obtained by the manufacturing method of each example, shortening of the fibrous filler (glass fiber) was evaluated by the following method. Further, after producing the resin composition, the ability to suppress screw wear was evaluated by the following method. These results are shown in Table 2.

[Short fiberization of fibrous filler]
The length weighted average fiber length and number average fiber length of the fibrous filler (glass fiber) present in the resin composition were directly determined from the appearance shape of the glass fiber after incineration.
That is, 1.0 g of glass fiber was collected, dispersed in methanol, and the shape (length) of the glass fiber was observed using a fiber length measuring device ("PITA-3" manufactured by Seishin Enterprise Co., Ltd.). It was determined by calculating the average value.
In addition, in calculating the average value, the parameter was set to 4000 or more. Regarding each weight, the weight for each fiber length was calculated from the specific gravity of the glass fiber, and the total weight of the sample used was used to calculate the average value.
The shortening of the fibrous filler was evaluated based on the determined length-weighted average fiber length and number-average fiber length according to the following evaluation criteria.
Evaluation criteria ○: Length weighted average fiber length less than 120 μm, number average fiber length less than 85 μm △: Length weighted average fiber length 120 μm or more and less than 150 μm, number average fiber length 85 μm or more and less than 100 μm ×: Length weighted average fiber length 150 μm or more , number average fiber length 100μm or more

[Suppression of screw wear]
After the production according to the above method for producing a resin composition, the screw was removed from the cylinder, the state of the screw element was visually confirmed, and the ability to suppress the wear of the screw was evaluated according to the following evaluation criteria.
Evaluation criteria ○: No wear was observed on the screw element.
Δ: Slight wear was observed on the screw element.
×: Wear was clearly observed on the screw element.

From the results shown in Table 2, the manufacturing methods of the resin compositions of Examples 1 to 10 to which the present invention was applied suppressed screw wear compared to the manufacturing methods of the resin compositions of Comparative Examples 1 to 8. It can be confirmed that it is possible to produce a resin composition in which the fibrous filler is more likely to have short fibers.

The present invention is applicable to electric/electronic parts, optical parts, semiconductor manufacturing process-related parts, home appliance parts, lighting equipment parts, audio product parts, communication equipment parts, printing press-related parts, automobile parts, cooking utensils, and civil engineering and construction parts. It can be used for various molded objects such as materials, parts for aerospace equipment, parts for medical equipment, sports goods, and leisure goods.

11 Motor, 12 Cylinder, 13 Screw, 14 First vent part, 15 Main feed port, 16 Second vent part, 17 Upstream side feed port, 18 Discharge die, 19 Downstream side feed port, 20 Conveyance part, 21 No. 1 kneading section, 22 second kneading section, 23 third kneading section, 100 extruder

Claims (7)

A method for producing a resin composition, the method comprising the step of melt-kneading a resin (A) and a fibrous filler (B) using an extruder,
The extruder includes a cylinder, a screw disposed in the cylinder, a main feed port provided in the cylinder, and an upstream side feed port provided rearward in the extrusion direction from the main feed port of the cylinder. , a downstream side feed port provided rearward in the extrusion direction from the upstream side feed port of the cylinder,
The resin (A) is introduced from the main feed port, the upstream side feed port, and the downstream side feed port,
The fibrous filler (B) is introduced from the upstream side feed port,
The amount of the fibrous filler (B) inputted from the upstream side feed port is 100% by mass with respect to 100% by mass of the total input amount of the fibrous filler (B),
The amount of the fibrous filler (B) introduced from the upstream side feed port is the total amount of the resin (A) and the fibrous filler (B) introduced from the upstream side feed port. 200/3% by mass or more relative to 100% by mass,
A method for producing a resin composition, wherein the amount of the resin (A) introduced from the downstream side feed port is greater than the amount of the fibrous filler (B) introduced from the downstream side feed port. The method for producing a resin composition according to claim 1, wherein the fibrous filler (B) in the resin composition has a length-weighted average fiber length of 30 to 140 μm. With respect to 100% by mass of the total input amount of the resin (A) and the fibrous filler (B),
The amount of the resin (A) introduced from the upstream side feed port is 1 to 20% by mass,
The method for producing a resin composition according to claim 1 or 2, wherein the amount of the resin (A) introduced from the downstream side feed port is 5 to 45% by mass. Any one of claims 1 to 3, wherein the content of the resin (A): the content of the fibrous filler (B) in the resin composition has a mass ratio of 75:25 to 50:50. A method for producing a resin composition as described in 2. The method for producing a resin composition according to any one of claims 1 to 4, wherein the resin (A) is a liquid crystal polymer. The method for producing a resin composition according to any one of claims 1 to 5, wherein the fibrous filler (B) is at least one selected from the group consisting of glass fibers and carbon fibers. A method for producing a resin molded article, comprising a step of molding a resin composition obtained by the method for producing a resin composition according to any one of claims 1 to 6.

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