JP2001310369A - Kneading method of liquid additive using single-section reverse screw notched screw - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To knead and extrude a resin and a liquid additive,
The extrusion efficiency is improved and the liquid additive is uniformly dispersed in the resin without causing troubles such as deterioration of the resin due to kneading heat and vent up due to insufficient kneading. SOLUTION: As a second kneading zone screw element of a twin-screw co-rotating extruder, 1 to 5 screw elements having all the following performances simultaneously (a), (b), (c) and (d) are used. I do. (A) The screw rotation direction is on the left when the extruder tip is viewed from the main hopper side. (B) Single thread screw. (C) 8 to 16 screw notches per pitch. (D) The length of the screw pitch is 0.1D to 0.5D.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a kneading method in which a resin is mixed with a liquid additive and extruded.

[0002]

2. Description of the Related Art The prior art relating to the relationship between the screw configuration and the liquid addition amount of a twin-screw co-rotating extruder is as follows. (1) JP-A-09-70872 describes an example in which a phosphate ester is added to polyphenylene ether. (2) Japanese Patent Application Nos. 09-122495 and 10-207
851 describes an example in which an olefin oil is added to a crosslinked product of an olefin elastomer.

[0003]

In the prior art, when a liquid additive is added to a resin, the length of the liquid additive kneading zone is increased. If the length of the kneading zone is increased, the heat generated by kneading may cause a decrease in Izod, a decrease in tensile strength (elongation), and an increase in MD. When the length of the kneading zone was shortened, the extrusion amount was reduced, the productivity was poor, and the resin was deteriorated (for example, the Izod was reduced, and the MD was increased).

[0004] When kneading a resin with a liquid additive, it has been required to achieve both the dispersibility of the liquid additive and high productivity. An object of the present invention is to improve the productivity by improving the kneadability of the liquid additive, and to improve the physical properties of the pelletized resin that is obtained through the extrusion.

[0005]

Therefore, in the present invention,
A twin-screw co-rotating extruder having a liquid additive kneading part, the screw screw turning direction used for the kneading part is counterclockwise as viewed from the tip of the extruder from the main hopper side, and a single screw, and a screw notch. 8-16 per pitch
An object of the present invention is to provide a kneading method characterized in that the screw has a screw shape in which the length of the screw is 0.1D to 0.5D.

Hereinafter, the present invention will be described in more detail. FIG. 1 schematically shows a twin-screw co-rotating extruder 1 according to claim 1 of the present invention. In FIG. 1, 2 is a main hopper, 3 and 7 are vent insert ports, 4 is a liquid addition nozzle, 5 is a liquid addition tank, 6 is a liquid addition pump, and 8 is a feeder. Examples of the twin-screw co-rotating extruder of the present invention include ZSK series manufactured by Warner & Friedler of Germany, TEM series manufactured by Toshiba Machinery Japan, and TEX series manufactured by Japan Steel Works.

[0007] The kneading zone of the extruder of the present invention requires two or more places. The first kneading zone melt-kneads the resin. For the screw parts used in the first kneading zone, the kneading zone is arbitrarily designed by combining one or more kinds of rightward, leftward, middle kneading discs, reverse screws, varistoring, and mixing screws. It is necessary to provide a second kneading zone downstream of the liquid addition nozzle for adding the liquid additive of No. 4. The screw parts to be used are necessary to uniformly knead the liquid additive by using 1 to 5 single-thread reverse screw notched screws of the present invention.

[0008] The single reverse screw notch screw of the present invention will be described in detail. (A) The screw rotation direction is counterclockwise when the extruder tip is viewed from the main hopper. This screw thread is usually called a reverse screw. (B) A single thread is a screw having only one flight crest when the screw rotates 360 degrees.

(C) The notch of the screw cuts the screw flight crest in the direction opposite to the direction around the screw. The notch effect is that a part of the mixture of the resin and the liquid additive flows back to the upstream side (extruder motor side) and mixes with the mixture of the resin and the liquid additive flowing upstream, so that the resin and the liquid additive are added. It is to promote the kneading of the agent. The number of notches is preferably 8 to 16 at equal intervals per screw pitch.
The total opening area for one pitch of the cutout portion is preferably in the range of 0.17 to 0.27 per screw cross-sectional area D × D / 4 × 3.14.

(D) The length of the screw pitch is the length of the screw when the screw rotates 360 degrees. Figure 3,
4 L _Z, L _S is the screw pitch. The length of the screw pitch ranges from 0.1D to 0.5D, preferably from 0.15D to 0.4D.

The liquid additive of the first aspect of the present invention includes:
For example, mineral oil, phosphate ester, silicone oil and the like can be mentioned. Mineral oils include, for example, paraffinic, naphthenic and aromatic oils, and phosphate esters such as triphenyl phosphate,
2,2-bis- {4- [bis (phenoxy) phosphoryloxy] phenyl} propane, 2,2-bis- {4-
Silicon oils such as [bis (methylphenoxy) phosphoryloxy] phenyl} propane,-(3-hydroxyphenyl) diphenyl phosphate, resorcinol bis (diphenyl phosphate) and the like include, for example, dimethyl silicone oil, methylphenyl silicone oil, methylhydrogen One or more of them can be used at the same time with gen silicone oil or the like. The feeder to be fed may be either a capacity type or a weight type, but a weight type is preferable.

The dimensionless extrusion amount of the present invention can be calculated by the following equation. However, DLQ is dimensionless extrusion amount,
Q is the throughput (m ³ / h), D is the screw diameter (m), n
Is the screw rotation speed (rps). DLQ = (Q / 3600) / (D × D × D) / (2 ×
3.14 × n) The dimensionless extrusion amount DLQ is preferably in the range of 0.005 to 0.025. The screw rotation speed of the extruder is 150 to 15
A range of 00 rpm is preferred.

The styrenic resin of the present invention is a homopolymer or a copolymer of a vinyl aromatic compound. As the vinyl aromatic compound, styrene, α-methylstyrene, α
-Ethylstyrene, α-methylstyrene-p-methylstyrene, o-methylstyrene, m-methylstyrene, each alkyl-substituted styrene such as p-methylstyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, p
-Halogenated styrenes such as -bromostyrene, dichlorostyrene, dibromostyrene, trichlorostyrene, tribromostyrene and the like can be mentioned, among which styrene and α-methylstyrene are preferable.

The olefin resin of the present invention is a propylene polymer or an olefin elastomer. Specific examples of the polypropylene polymer used in the present invention include homo isotactic polypropylene, propylene and ethylene, butene-1, pentene-1, and hexene-.
And isotactic copolymers (including block and random) with other α-olefins such as 1. At least one polymer selected from these polymers is used in a composition ratio of 5 to 90 parts by weight. If the amount is less than 5 parts by weight, the fluidity and processability of the composition will be reduced, and if it exceeds 90 parts by weight, the flexibility of the composition will be insufficient, which is not desirable.

The propylene polymer used in the present invention has a melt index of 0.1 to 100 g / 1.
Those in the range of 0 minutes (230 ° C., 2.16 kg load) are preferably used. If it exceeds 100 g / 10 minutes, the heat resistance and mechanical strength of the thermoplastic elastomer composition will be insufficient, and if it is less than 0.1 g / 10 minutes, the fluidity will be poor and the moldability will be reduced, which is not desirable. .

The olefin elastomer used in the present invention comprises ethylene and at least one or more carbon atoms having 3 carbon atoms.
To α-olefins having a specific density and a specific molecular weight distribution. As the α-olefin having 3 to 12 carbon atoms, for example, propylene, butene-1, pentene-1,
Hexene-1, 4-methylpentene-1, heptene-
1, nonene-1, decene-1, undecene-1, dodecene-1 and the like.

The olefin-based elastomer is preferably produced using a known metallocene-based catalyst. The metallocene-based catalyst is composed of a cyclopentadienyl derivative of a Group IV metal such as titanium and zirconium and a co-catalyst, and is not only highly active as a polymerization catalyst, but also compared with a conventional catalyst, for example, a Ziegler-based catalyst, The molecular weight distribution of the obtained polymer is narrow, and the comonomer in the copolymer has 3 to 3 carbon atoms.
It is characterized in that the distribution of α-olefins of No. 12 is uniform.

An olefin elastomer produced by using a metallocene catalyst has greatly different properties of a polymer obtained as compared with a conventional one using a Ziegler catalyst or the like. To list the characteristics of the olefin elastomer using a metallocene polymerization catalyst,

1. Since the polymerization catalyst has high activity, the composition of the comonomer α-olefin can be greatly increased as compared with the conventional one, and an elastomeric polymer having high flexibility can be obtained even without a plasticizer. 2. The comonomer distribution is uniform compared to Ziegler-based polymers. 3. Compared with Ziegler-based polymers, the molecular weight distribution is extremely sharp, the amount of low molecular weight components is extremely small, the mechanical strength and processability are excellent, and the quality is high.

4. ASTM D123 when long-chain branching was introduced despite the sharp molecular weight distribution
8. Melt index (I10) at 190 ° C./10 kgf, 190 ° C./2.16 k
gf to the melt index (I2) (I1
0 / I2) is large and has excellent processing characteristics. 5. It does not contain a gen component and has excellent environmental degradation resistance. 6. Even if the α-olefin copolymerization ratio is high, blocking hardly occurs and a pellet-like form is possible. And so on.

In the case of an olefin-based elastomer which is a copolymer of ethylene and an α-olefin with a Ziegler catalyst, the above-mentioned melt index ratio (I10 / I2) and the molecular weight distribution show a substantially linear proportional relationship. The molecular weight distribution tends to increase with the increase. The molecular weight distribution is usually about 3 to 10. On the other hand, in the case of an olefin polymer using a metallocene catalyst, the molecular weight distribution becomes a sharp value of less than 3.0, and the low molecular weight component is extremely small, regardless of the value of the melt index ratio. For this reason, workability is extremely excellent.

The molecular weight distribution of these olefinic elastomers is determined by high-temperature GPC using trichlorobenzene as a solvent.
Is calculated by Density is 0.8-0.9 g / cm ³
Are preferred. By using an olefin elastomer having a density in this range, a thermoplastic elastomer composition having excellent flexibility and low hardness can be obtained. The olefin elastomer used in the present invention has a melt index of 0.01 to 100.
g / 10 minutes (190 ° C., 2.16 kg load) are preferably used, and more preferably 0.2 to 10 g.
/ 10 minutes. If it exceeds 100 g / 10 minutes, the crosslinking property of the thermoplastic elastomer composition will be insufficient, and if it is less than 0.01 g / 10 minutes, the fluidity will be poor and the processability will be undesirably reduced.

The olefin-based elastomer having the above-mentioned specific structure has surprisingly excellent radical crosslinkability comparable to conventional EPDM, and the crosslinkable elastomer component of the thermoplastic elastomer composition by dynamic crosslinking. Is the most suitable polymer. The olefin-based elastomer used in the present invention may be a mixture of a plurality of types. Workability can be improved.
As olefin-based elastomers composed of ethylene produced by a metallocene-based catalyst and at least one or more α-olefins having 3 to 12 carbon atoms, products such as “Engage” of DuPont Dow Elastomers are known.

The ABS resin of the present invention is a copolymer of acrylate monomer and / or methacrylate monomer acrylonitrile and / or styrene monomer and butadiene, or 100 to 100 parts by weight of this copolymer containing 10 to 200 parts by weight of polycarbonate. . In the present invention, between the first kneading zone and the second kneading zone or / and downstream of the second kneading zone, a thermoplastic resin, a filler, a fiber, a conductive filler (Ketjen black, acetylene black), an anti-drip agent ( Teflon (registered trademark), silicone resin) and other additives may be added.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. First, the meanings of the symbols indicating the screws used in the second kneading zone of the following Examples and Comparative Examples are as shown in Table 1 below. In addition, "A" shown in the type column of Table 1 is a single-start reverse screw element (A),
“B” is a two-section notched screw element (B),
“C” and “D” mean a needing disc, respectively.

[0026]

[Table 1]

The extruder is based on a twin-screw co-rotating extruder ("ZSK-40" manufactured by Warner & Friedler Co., L / D = 46, 11 barrels) as shown in FIG. Experiments were conducted mainly with variously changing the screw configuration of the second kneading zone. All feeders used heavy-weight feeders to minimize torque fluctuations.
Extrusion conditions were a screw rotation speed of 300 rpm and a vent as an atmospheric vent unless otherwise specified.

The results of the examples and comparative examples are summarized in Table 2. The measurement method of the measurement items shown in this table is as follows. The maximum extruding amount without liquid separation is visually observed with a die at the tip of the extruder for the presence of vent-up and for the separation of liquid additives. The physical properties were measured using an injection molding machine for pellets formed by an extruder. The cylinder temperature is
The temperature was 240 to 260 ° C, and the mold temperature was 60 ° C. I
The zod was evaluated on a 1/8 inch notched fence according to ASTM D256. Elongation was evaluated with a 1/8 inch dumbbell according to ASTM D658.

[0029]

Example 1 50 parts by weight of powdery polyphenylene ether (PPE) having a reduced viscosity of 0.53 and 50 parts by weight of high-impact polystyrene ("H9405" manufactured by Asahi Kasei Kogyo Co., Ltd.) were fed from a main hopper to 100 parts by weight of resin. 24 parts by weight of a liquid additive (“CR741” manufactured by Daihachi Chemical Co., Ltd.) was added from a liquid addition nozzle in the middle of the extruder, and the extruder barrel temperature was 30.
At 0 ° C., the amount of extrusion, the presence or absence of vent up, and the presence or absence of liquid separation were confirmed. The screw element of the second kneading zone
The kneading zone length was 60 mm using three pieces of (A). The upper limit of the throughput was 120 kg / h. The operation was performed for 1 hour without occurrence of vent-up and separation of liquid, but no trouble occurred.

[0030]

Example 2 The same observation was performed as in Example 1 except that two screw elements (A) in the second kneading zone were used and the length of the kneading zone was 40 mm. The upper limit of the throughput was 90 kg / h. The operation was performed for 1 hour without occurrence of vent-up and separation of liquid, but no trouble occurred.

[0031]

Example 3 The same observation was performed as in Example 1, except that one screw element (A) in the second kneading zone was used and the length of the kneading zone was 20 mm. The upper limit of the extrusion rate was 50 kg / h. The operation was performed for 1 hour without occurrence of vent-up and separation of liquid, but no trouble occurred.

[0032]

Comparative Example 1 The same observation was performed as in Example 1 except that two screw elements (B) in the second kneading zone were used and the length of the kneading zone was 50 mm. The upper limit of the extrusion rate was 50 kg / h. The apparatus was operated for 1 hour without occurrence of vent-up and liquid separation, but no trouble occurred, but the extrusion rate was lower than that in Example 2.

[0033]

Comparative Example 2 The same observation was performed as in Example 1 except that the kneading zone length was 90 mm using the screw elements (C), (B), (B) and (D) of the second kneading zone. went. The upper limit of the throughput was 90 kg / h. The apparatus was operated for 1 hour without occurrence of vent-up and liquid separation, but no trouble occurred. However, the length of the kneading zone was longer than in Example 1, but the extrusion rate was low.

[0034]

Comparative Example 3 The same observation was performed as in Example 1 except that the kneading zone length was 80 mm using the screw elements (C), (C), (C) and (D) of the second kneading zone. went. The upper limit of the throughput was 80 kg / h. The operation was performed for 1 hour without occurrence of vent-up and separation of liquid, but no trouble occurred. The length of the kneading zone was longer than in Example 1, but the extrusion rate was lower.

[0035]

Example 4 High-density polyethylene ("J" manufactured by Asahi Kasei Corporation)
-241 ") 100 parts by weight of the main hopper and 100 parts by weight of the resin and a liquid additive (" KP-
68 ") The same observation was performed as in Example 1 except that 30 parts by weight was added from a liquid addition nozzle in the middle of the extruder, and the barrel temperature of the extruder was set to 250 ° C. The extrusion rate is 100kg /
h was the upper limit. The operation was performed for 1 hour without occurrence of vent-up and separation of liquid, but no trouble occurred.

[0036]

Embodiment 5 The resin is an engaged crosslinked product, and the resin 10
0 parts by weight of a liquid additive (“PW-38” manufactured by Idemitsu Kosan Co., Ltd.)
0 ") 50 parts by weight were added through a liquid addition nozzle in the middle of the extruder, and the extruder barrel temperature was 200 ° C., the amount of extrusion, the presence or absence of venting, and the presence or absence of liquid separation were confirmed. Screw rotation speed 2
The screw element of the second kneading zone at 50 rpm is
The kneading zone was 100 mm in length using 5 pieces of (A).
The upper limit of the throughput was 60 kg / h. The operation was performed for 1 hour without occurrence of vent-up and separation of liquid, but no trouble occurred.

[0037]

Comparative Example 4 The same observation was performed as in Example 5, except that three screw elements (A) were used and the length of the kneading zone was 60 mm. The upper limit of the extrusion rate was 45 kg / h. The operation was performed for 1 hour without occurrence of vent-up and separation of liquid, but no trouble occurred.

[0038]

Example 6 The resin was polycarbonate (number average molecular weight 25
000), 80 parts by weight of ABS (rubber content: 22 wt%, number average molecular weight: 140,000), 20 parts by weight of resin, and 100 parts by weight of resin, liquid additive ("CR741" manufactured by Daihachi Chemical Co., Ltd.)
30 parts by weight were added through a liquid addition nozzle in the middle of the extruder, and the extruder was extruded at a barrel temperature of 290 ° C., vented,
The presence or absence of liquid separation was confirmed. The screw element of the second kneading zone uses three pieces of (A) and has a kneading zone length of 60.
mm. The upper limit of the extrusion rate was 100 kg / h.
The operation was performed for 1 hour without occurrence of vent-up and separation of liquid, but no trouble occurred.

[0039]

[Table 2]

[0040]

According to the present invention, the twin-screw co-extrusion process with a single notch screw disperses the liquid additive uniformly in the resin and does not cause the resin to deteriorate due to kneading. This can improve the productivity of the resin in the form of pellets.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing an extruder according to the present invention.

FIG. 2 is an explanatory diagram of an extruder used in Examples and Comparative Examples.

FIG. 3 is an explanatory view of a single notched screw (A).

FIG. 4 is an explanatory view of a two-row notched screw (B).

FIG. 5 is an explanatory diagram of a needing disk (C).

FIG. 6 is an explanatory diagram of a needing disk (D).

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 extruder 2 main hopper 3 vent insert port 4 liquid addition nozzle 5 liquid addition tank 6 liquid addition pump 7 vent insert port 8 feeder

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29K 71:00 B29K 71:00 F term (Reference) 4F201 AA03 AA13 AA32K AB07 AM24 AR09 AR12 BA01 BC01 BC13 BC33 BK02 BK13 BK26 BK41 BK47 BK75 4F207 AA03 AA32 AB07 KA01 KA17 KF03 KK13 KL06 KL23

Claims (5)

[Claims] 1. A kneading method in which 100 parts by weight of a resin is melt-kneaded using a twin-screw co-rotating extruder for kneading a liquid additive to a resin, and then 5 to 100 parts by weight of a liquid additive is added. A kneading zone for uniformly kneading the additive with at least one screw element having all of the following properties (a), (b), (c) and (d) at the same time; (L _ZL ) is 0.2D to 2.5
A method of kneading a liquid additive, wherein D is a screw diameter. (A) The screw rotation direction is counterclockwise when the extruder tip is viewed from the main hopper side. (B) Single thread screw (c) The number of screw notches is 8 to 16 per pitch. (D) Length of screw pitch L _S is 0.1D to 0.5D 2. The method for kneading a liquid additive according to claim 1, wherein the extruding is carried out under conditions that simultaneously satisfy the following conditions (e) and (f). (E) The dimensionless extrusion amount (DLQ) is 0.005 to 0.02
5 (f) Screw rotation speed Rotation speed is 150 rpm to 1500
rpm 3. The kneading method according to claim 1, wherein the resin is a polyphenylene ether and / or a composition of polyphenylene ether and a polystyrene resin, and the liquid additive is a phosphoric acid ester. 4. The method according to claim 1, wherein the resin is an olefin composition and the liquid additive is a paraffin oil. 5. The kneading method according to claim 1, wherein the resin is an ABS composition, and the liquid additive is a phosphoric acid ester.