KR102373495B1 - Preparation Method of Anti-drip Agent for Polycarbonate-based Resins Using Twin Screw Extruder - Google Patents

Abstract

In the present disclosure, disclose are: a method for manufacturing a master batch type anti-drip agent advantageous in terms of productivity and process simplification, such as not requiring a post-process required in a conventional reactive production method by using a twin-screw extruder comprising a specific area; and a polycarbonate-based resin composition using the same.

Description

Preparation Method of Anti-drip Agent for Polycarbonate-based Resins Using Twin Screw Extruder

The present disclosure relates to a method for manufacturing a drip preventing agent for a polycarbonate-based resin using a twin-screw extruder. More specifically, the present disclosure relates to the production of a master batch type anti-drip agent advantageous in terms of productivity and process simplification, such as not requiring a post-process required in a conventional reactive manufacturing method, using a twin-screw extruder comprising a specific area. It relates to a method, and a polycarbonate-based resin composition using the same.

Polycarbonate (PC) is a type of thermoplastic polymer and has a carbonate group in the main chain, and since it has good formability as well as strength, toughness and optical transparency, various fields (e.g., architecture, automobile, aircraft, data storage, It has high usefulness in electricity, communication equipment, etc.). However, since polycarbonate also has problems such as strong hydrophobicity, limited chemical functionality, and high melt viscosity, blends with other polymers, such as PC/PE, PC/PMMA, PC/PVC, PC/PS, PC/ ABS is also used.

Since polycarbonate resins are vulnerable to heat due to the inherent properties of organic polymers, additives such as flame retardants (eg, dyes and pigments) are generally mixed. In particular, in order to meet the flame-retardant test standard prescribed by UL94, a flame-retardant auxiliary agent providing an anti-dripping function is used together. In general, the anti-drip agent is artificially added during the compounding process of the polymer, and has a function of suppressing the drip phenomenon of the polymer composition when exposed to a high (combustion) temperature.

In this regard, polytetrafluoroethylene (PTFE) or modified PTFE is widely used as an anti-drip agent for various resins, and PTFE is typically applied in a dispersed form as solid particles in a matrix resin. PTFE is known to have excellent heat resistance, chemical resistance, and electrical insulation properties, good water and oil repellency, non-tackiness, self-lubrication, and the like, and can improve moldability and mechanical properties when blended with a thermoplastic resin. In particular, the anti-drip effect of PTFE stems from the unique morphological characteristics of PTFE polymer with high crystallinity.

In general, PTFE provides good anti-drip performance, but due to the recent development of technology, it causes problems in storage or storage due to phenomena such as agglomeration due to the use of PTFE particles having a significantly smaller size. In addition, since PTFE is used in the form of solid coarse particles, it causes an undesirable phenomenon in the surface quality of the resin molding.

In contrast, an encapsulated PTFE product in which the surface of PTFE polymer particles is coated with a specific organic component has been developed, which is a method of improving surface quality and storage while maintaining flame retardancy and drip prevention. As described above, as the organic component forming the capsule, styrene, acrylonitrile, acrylate-based resin, and the like are mostly used.

However, conventionally, a reaction-type method is mainly adopted, and representatively, an emulsion reaction, a suspension reaction, and the like can be exemplified. In the case of manufacturing the anti-drip agent in such a reactive manner, post-processes such as dehydration and drying of the product must be performed because a large amount of water is used due to the reaction characteristics, and the quality of the anti-drip agent is deteriorated in the process of performing the post-process, etc. This often happens. In particular, since the drying step of the post-process has to be performed over a long period of time, it not only reduces the productivity of the entire manufacturing process, but also acts as a factor complicating the manufacturing process.

Furthermore, in engineering plastics (mainly for cover housings in the electrical and electronic fields) flame retardancy (eg UL flame retardant V-0) and flawless surface quality are simultaneously required. In particular, when conventional encapsulated PTFE is applied to a polycarbonate-based resin or a blend thereof (for example, PC/ABS) that requires high gloss properties, deterioration of the surface quality of the molding is a problem. The lower it is, the more pronounced it is. As the cause, the particle size of PTFE itself, aggregation between PTFE, and deterioration of compatibility with the matrix resin are pointed out.

Therefore, there is a need for a method for manufacturing a PTFE-based anti-drip agent that overcomes the technical limitations of the prior art and has good anti-drip ability and surface properties for a polycarbonate resin or a blend thereof, which is a simpler and more convenient matrix resin.

In one embodiment of the present disclosure, when introduced as an anti-drip agent, which is a kind of flame-retardant auxiliary agent, into a polycarbonate-based resin or a blend thereof, good drip prevention and surface quality effect can be provided, and it is convenient and high productivity compared to the conventional chemical reaction type An object of the present invention is to provide a method for manufacturing an anti-drip agent that can achieve

According to one embodiment of the present disclosure,

a) according to the moving direction of the raw material, (i) a feeding area provided with a main feeder including a first feeder and a second feeder for introducing the raw material into the barrel, (ii) a conveying area of the introduced raw material, ( iii) a melting section, a first kneading block, a transition element provided with at least one side feeder, a mixing section sequentially including a moving section and a second kneading block, and (iv) the raw material passing through the mixing section providing a twin screw extruder comprising a processing region that extrudes into the die direction;

b) introducing a combination of a first raw material polycarbonate and a second raw material polycarbonate and an additive through the first feeder into the barrel of a twin-screw extruder to form a first raw material mixture, the the first raw material and the second raw material are each in a solid form;

c) conveying the introduced first raw material mixture in a die-side direction in a conveying area;

d) The first raw material mixture that has passed through the transfer region is transferred to the mixing region, and a third raw material containing polytetrafluoroethylene is introduced through the side feeder along with it and melted and kneaded in the mixing region to form a molten material. forming a second raw material mixture;

e) transferring the second raw material mixture that has passed through the mixing region in the processing region to the end of the barrel while maintaining a molten state;

f) discharging the second raw material mixture that has passed through the processing region into an extrudate by means of a die; and

g) cooling the discharged extrudate and then cutting it into a desired shape and/or dimension;

There is provided a method for producing a drip preventing agent for a master batch type polycarbonate-based resin comprising a.

According to an exemplary embodiment, the moving part further includes a first vent hole, and the step of degassing the gas contained in the second raw material mixture through the first vent hole is performed, and

A second vent hole may be further provided in the processing region, and a step of degassing gas contained in the second raw material mixture through the second vent hole may be performed.

According to an exemplary embodiment, the second raw material introduced into the second feeder is (i) 60 to 90 wt% of polycarbonate, and (ii) at least one additive selected from the group consisting of a heat stabilizer and a mold release agent 10 to 40% by weight.

According to an exemplary embodiment, the polytetrafluoroethylene in the third raw material may have a particle diameter in the range of 0.01 to 0.95 μm and a molecular weight (M _w ) in the range of 3,000,000 to 10,000,000.

According to an exemplary embodiment, the temperature (T) of the transition part provided with the side feeder in the mixing area is set at 240 to 260 ℃,

The temperature of each of the first kneading block and the second kneading block is set in a range of 25 to 50° C. lower than T, and 5 to 30° C. higher than T,

The temperature of the melt is set within the range of T, and

The temperature of the moving part may be set in a range of 5 to 30°C higher than T.

According to an exemplary embodiment, the temperature of the feeding area and the conveying area may be set in a range of 25 to 50° C. lower than T.

According to an exemplary embodiment, the temperature of the processing region may be set in a range of 5 to 30° C. higher than T.

According to an exemplary embodiment, the cooling temperature of step g) may be determined in the range of 30 to 60 ℃.

According to an exemplary embodiment, the size of the cut product obtained in step g) may be in the range of 10 to 60 mm.

According to an exemplary embodiment, the screw in the twin-screw compressor may rotate in a counter-rotation.

According to an exemplary embodiment, a weight ratio of polycarbonate to polytetrafluoroethylene among all the raw materials supplied to the twin-screw compressor may be in the range of 1:0.6 to 1.5.

According to an exemplary embodiment, the ratio of the length (L)/diameter (D) of the barrel in the twin screw extruder may be set in the range of 20 to 36.

According to an exemplary embodiment, a weight ratio of the first raw material to the second raw material introduced from the feeding area may be set in the range of 1:0.1 to 0.5.

According to another embodiment of the present disclosure,

100 parts by weight of polycarbonate-based resin or polycarbonate-based resin-based blend;

0.5 to 20 parts by weight of a flame retardant; and

0.1 to 1 part by weight of the master batch type anti-drip agent prepared according to the above-described method;

There is provided a polycarbonate-based resin composition having improved anti-drip properties and flame retardancy comprising a.

According to an exemplary embodiment, the flame retardant may be at least one selected from the group consisting of an organic salt-based flame retardant, a halogen-based aromatic flame retardant, and an aromatic phosphate-based flame retardant.

The master batch type anti-drip agent for a polycarbonate-based resin or a blend thereof prepared according to an embodiment of the present disclosure uses polytetrafluoroethylene (PTFE) used as an existing anti-drip agent, a polymer of the same type as polycarbonate as a matrix resin. By combining with and using a twin-screw compressor equipped with at least one pair of main feeders and at least one side feeder to use as a flame retardant auxiliary agent or drip preventing agent for polycarbonate-based resins, through improved dispersibility due to good compatibility It is possible to prepare a polycarbonate-based resin or a blend thereof having excellent surface quality and flame retardant properties of the molded article. In particular, since it does not require post-processes such as dehydration and drying, which are required in the case of manufacturing in the conventional reactive method, problems such as productivity improvement, simplification of the manufacturing process, and quality degradation due to post-processing are eliminated at once. advantages that can be overcome. Therefore, widespread commercialization is expected in the future.

1 is a diagram showing the structure and dimensions in a twin screw extruder for producing a master batch type anti-drip agent; And
2 is a photomicrograph showing the surface quality test results for Example 8 and Comparative Example 4, respectively.

The present invention can all be achieved by the following description. It is to be understood that the following description describes preferred embodiments of the present invention, and the present invention is not necessarily limited thereto. In addition, the accompanying drawings are provided to aid understanding, and the present invention is not limited thereto, and details regarding individual configurations may be properly understood by the specific purpose of the related description to be described later.

Terms used herein may be defined as follows.

"Polycarbonate" is a homopolycarbonate having a repeating unit of a carbonate represented by the following general formula 1 and a concept including a copolycarbonate comprising a repeating unit of a carbonate and another polymer repeating unit (eg, an ester moiety) can be understood as

[General formula 1]

In the above formula, R may be derived from a diol or dihydroxy compound including aliphatic, cycloaliphatic, aromatic, or a combination thereof.

"Polytetrafluoroethylene (PTFE)" is understood to include homopolymers and copolymers in a broad sense, such as poly(tetrafluoroethylene), (poly(tetrafluoroethylene-co-hexafluoropropylene), and the like. and may be understood to refer only to poly(tetrafluoroethylene) in a narrow sense.

“Extrusion” may refer to a molding method in which raw materials are heated and fluidized in a barrel under the operation of a screw using an extruder, continuously extruded from a die plate, cooled, and commercialized. In this regard, the screw comprises a cylinder cut to have a helical channel, and as the screw rotates within the barrel, a raw material introduced from a hopper or the like, typically a polymer raw material, is fed into the screw channel (i.e., between the flights of the screw). open space) to the die.

"twin screw extruder" means an extruder in which a pair of screws operate together in a common barrel, wherein a pair of screws are arranged in parallel and may or may not be interdigitated, or identical It may be a co-rotation method or a counter-rotation method for rotating in the direction.

"Side feeder" may mean a feeder for dispensing certain ingredients (raw materials and/or additives) at a location in the extrusion process area other than the initiation area (eg, the area where the main feeder is located) within the extruder. The ingredients fed through the side feeder are conveyed into the extruder in transverse movement, typically by pumping, where they can be combined with the melt in the barrel in a proportion.

In the present specification, when a component is "included", it means that other components may be further included unless otherwise specified.

Terms such as “above” or “above” and “below” or “below” may be understood to describe the relative positional relationship between components or members, and may be understood to describe a relative positional relationship between components or members, “located above” or “underlying”. The term “located” may be understood to express a relative positional relationship in a state not in contact with a specific object as well as in a state in which the object is not in contact.

Preparation of master batch type anti-drip agent

The structure and dimensions in a twin screw extruder for making a stub batch type anti-drip agent according to an exemplary embodiment of the present disclosure are shown in FIG. 1 .

Referring to the drawings, the twin screw extruder is provided with a conveying screw and a kneading block. Specifically, two rotating shafts (shafts) are provided in the barrel and a pair of feed screws are arranged to engage with each rotation axis, and the kneading block may also be configured to engage with each rotation axis corresponding to the pair of screws.

According to the illustrated embodiment, the twin-screw extruder is a feeding zone (A), a conveying zone (B), a mixing zone (C) and a processing zone in the order of movement of the introduced raw material. (D) consists of the order.

A die E is disposed at the rear end of the processing region D so that the raw material (or raw material mixture) passing through the processing region is discharged as an extrudate. Thereafter, the extrudate passes through a cooling zone G and is cut into a predetermined shape and dimension in a cutting zone F. In this regard, the names mentioned in each of the above four areas and individual physical configuration or overall design that can perform the corresponding functions are described in related literature, for example, Extrusion Cooking (Second Edition), Cereal Grains Processing, 2020, Pages 73-117; Plastics Additives & Compounding, Understanding the Extruder Processing Zone: the heart of a twin screw extruder, 2008, etc., to the extent that the document is incorporated herein by reference. Accordingly, a detailed description thereof will be omitted.

In the illustrated embodiment, a pair of screws 102 are configured to rotate in parallel in the barrel 101, and for this purpose, a drive motor (not shown) and a gearbox (not shown) provided on the outside This causes each screw to rotate at a predetermined speed. In this regard, the rotational speed of the screw may be, for example, about 200 to 600 rpm, specifically about 300 to 500 rpm, more specifically about 400 to 450 rpm within the range. In addition, each of the barrel 101 and the screw 102 may be made of, for example, a material such as stainless steel (eg, SUS 304).

According to an exemplary embodiment, the twin screw extruder may be operated in a counter-rotation mode, which may provide effective dispersing force as compared to a co-rotation mode.

In addition, a heating or cooling member (not shown) is provided on the barrel 101 to adjust or maintain a desired temperature. At this time, the screw 102 largely includes a rotation shaft (shaft) and a flight (flight) formed spirally along the outer peripheral surface thereof. Accordingly, the raw material introduced into the barrel 101 moves in the die-side direction according to the rotation of the pair of screws 102 . In addition, the kneading block may include a variable number of kneading discs that may be staggered at positive angles, neutral angles (ie, 90°), and negative angles.

According to an exemplary embodiment, the ratio of the length (L)/diameter (D) of the barrel 101 is a factor affecting the discharge amount of the extrudate, for example, about 20 to .36, specifically about 22 to 34, more specifically It can be determined in the range of about 24 to 32. When the L/D value is too low, it is difficult to achieve the desired level of kneading, etc., whereas when the L/D value is too large, there is a possibility that excessive force is applied to the rotating shaft (shaft) of the screw, so it is to be determined within the above-mentioned range. can be advantageous However, this embodiment is not limited thereto.

According to this embodiment, in consideration of the characteristic properties and kneading (or rheological) properties of polycarbonate, which is one of the raw materials of the anti-drip agent, and the property of polytetrafluoroethylene (PTFE), which provides the main anti-drip function, the extrusion It is worth noting that the conditions, specifically, the method of injecting the raw material using at least one pair of main feeders and at least one side feeder is adopted. Additionally, a twin-screw extruder in which a specific temperature profile is set for each region of the twin-screw extruder may be used for the purpose of suppressing the deterioration of PTFE that may be caused during the processing for uniform mixing of polycarbonate and PTFE.

Referring to FIG. 1 , the twin-screw compressor can be largely divided into four regions and nine barrel regions constituting them. Among them, the first barrel section corresponds to the feeding area (A) and the conveying area (B), and the second to seventh barrel sections constitute the mixing area (C). For the mixing zone (C), the second barrel zone is the melt, the third barrel zone is the first kneading floe, the fourth barrel zone is the transition zone, the fifth and sixth barrel zones are the moving part, and the seventh barrel zone forms a second kneading block. In addition, the eighth and ninth barrel regions constitute the processing region (D).

According to an exemplary embodiment, relative to the barrel 101 , the feeding zone A and the transfer zone B (ie the first barrel zone): the mixing zone C (ie the second to seventh barrel zones). ) : The ratio (length) of the processing region D (ie, the eighth and ninth barrel regions) is, for example, 1: about 3 to 25: about 1 to 15 (specifically, 1: about 4 to 20: about 2 to 12, and more specifically 1: about 6 to 15: about 3 to 5).

According to one embodiment, in consideration of the unique properties of each of the plurality of raw materials (specifically, PC and PTFE), in particular, the rheological properties during the extrusion process, the twin-screw extruder is divided into four areas (A, B, C and D). It can be configured and the temperature profile in the barrel zone corresponding to each zone can be set in a way that is distinct from conventional twin screw extruders. In addition, a twin-screw extruder is used instead of a single-screw extruder to combine two different types of polymers, such as polycarbonate and PTFE, and further mix/knead them into a uniform composition while containing more additives.

However, when PTFE is introduced together with polycarbonate into the twin screw extruder, excessive heat may occur due to a high shear phenomenon, which may deteriorate the components in the extruded master batch. Therefore, when a molded article (ie, a molded article of a polycarbonate-based resin) is manufactured by using it as an anti-drip agent, the surface quality may be deteriorated. In consideration of the above, it is possible to minimize the shear stress by lowering the internal temperature of the extruder to a significant level compared to the compounding process using a conventional twin screw extruder.

According to an exemplary embodiment, the temperature of another region or the barrel region may be determined based on the temperature T of the transition portion provided with the side feeder for injection of PTFE in the mixing region C. In this regard, the temperature T of the transition (the fourth barrel section in FIG. 1 ) is, for example, in the range of about 240 to 260 °C, specifically about 245 to 255 °C, more specifically about 248 to 252 °C. can be determined

Once the temperature T at the transition in the mixing zone C is determined, in the case of the feeding zone A and the transfer zone B, where the solid raw material is processed (i.e. the first barrel zone), for example, It can be controlled to a lower range of about 25 to 50 °C than T, specifically about 30 to 45 °C than T, and more specifically about 35 to 40 °C.

The temperature of the melting section (second barrel section) in the mixing region C may be defined within the range of T, and may be the same as or different from the temperature at the transition section within the range. In addition, in the case of the temperature of the first kneading block (third barrel zone) in the mixing zone C, for example, about 25 to 50° C. than T, specifically about 30 to 45° C. than T, and more specifically about 35 to about 35° C. 40 ℃ lower range can be adjusted.

On the other hand, the temperature in the moving part (the fifth and sixth barrel zones) is, for example, in the range of about 5 to 30 °C higher than T, specifically about 7 to 25 °C higher than T, and more specifically about 10 to 20 °C higher. can be determined in

The temperature of the second kneading block (seventh barrel zone) may be set, for example, in a range of about 5 to 30 °C higher than T, specifically about 7 to 25 °C higher than T, and more specifically about 10 to 20 °C higher. there is. According to a specific embodiment, the temperature of the moving unit and the second kneading block may be set or adjusted to be the same.

In addition, in the case of the processing region (8th and 9th barrel zones), for example, it is set in a range of about 5 to 30 ℃ higher than T, specifically about 7 to 25 ℃ higher than T, and more specifically about 10 to 20 ℃ higher. can get According to a specific embodiment, the temperature of the processing region may be set or adjusted to be the same as the temperature of at least one of the moving unit and the second kneading block.

According to the illustrated embodiment, first, in the feeding area A, the first raw material and the second raw material are each configured to be introduced into the barrel of the twin screw extruder through at least a pair of main feeders. The main feeder includes a first feeder 111 and a second feeder 112 , and each of the first feeder and the second feeder may be a gravimetric feeder. In addition, the first raw material and the second raw material may be introduced into the barrel 101 through the supply member after being metered and supplied in a predetermined ratio to a single supply member in the feeding area A. Alternatively, they may be individually introduced into the barrel 101 without being previously combined. In this way, the additive is uniformly dispersed in the master batch finally manufactured by introducing the second raw material in the form of combining the additive with the polycarbonate into the twin-screw extruder through the first raw material and the separate feeder made of polycarbonate. can be

According to the illustrated embodiment, in the case of the first feeder 111 , it may typically be a hopper, and polycarbonate is introduced as the first raw material. In this case, the polycarbonate, which is the first raw material, may be prepared through an interfacial polymerization process between dihydric phenol and phosgene, a melt-esterification process between bisphenols and carbonate ester, and the like. According to an exemplary embodiment, the molecular weight (Mw) of the polycarbonate in the first raw material is, for example, about 8,000 to 100,000, specifically about 10,000 to 50,000, more specifically about 15,000 to 30,000, particularly about 17,000 to 20,000 may be in the range of

In addition, polycarbonate as a first raw material has a melt index (300° C., 1.2 kg) measured according to ASTM D1238, a medium viscosity, for example, about 8 to 20 g/10 min, specifically about 9 to 18 g/10 min. , More specifically, it may be in the range of about 8 to 14 g/10 min, the melt index of the polycarbonate in the first raw material affects flowability, dispersibility of PTFE, ease of extrusion, shear stress, etc. in the extrusion process, It may be advantageous to adjust within the aforementioned range.

On the other hand, a second raw material containing polycarbonate and additives is introduced through the second feeder 112, which may be a hopper similar to that described with respect to the first feeder, and is also fed into a single supply member after weighing. 1 It may be introduced into the barrel by introducing it together with the raw material, or may be introduced separately into the barrel. In this regard, the content of each of the polycarbonate and additive components in the second raw material is, for example, about 60 to 90% by weight (specifically, about 65 to 85% by weight, more specifically about 70 to 80% by weight) and about It may be adjusted in the range of 10 to 40% by weight (specifically, about 15 to 35% by weight, more specifically, about 20 to 30% by weight).

According to an exemplary embodiment, the polycarbonate in the second raw material is the same type as the first raw material polycarbonate, or meets the property requirements required for the above-described first raw material polycarbonate, but is produced within the range of the property. 1 It may be a different kind from the raw material.

According to an exemplary embodiment, at least one of a heat stabilizer and a mold release agent may be included as an additive component in the second raw material. In this regard, the thermal stabilizer performs a function of preventing degradation of the polymer during the extrusion process. As an example, the heat stabilizer may be, for example, at least one selected from phosphate, phosphite, phosphonate, and the like. As such an additive, an organophosphite (specifically, triphenyl phosphite, tris-(2, At least selected from 6-dimethylphenyl)phosphite, tris-(mixed mono- and di-nonylphenyl)phosphite, etc.), phosphonate (specifically trimethyl phosphonate), phosphate (specifically trimethylphosphate), etc. One bar can be used, and representatively, Songnox 2112 (semi-bead type, crystalline powder type, etc.) commercially available from Songwon can be used.

In addition, the release agent functions to easily detach from the mold surface during the molding (specifically, extrusion) process, for example, a fatty acid ester-based release agent, a stearate-based release agent (specifically, glycerol stearate, butyl stearate) , pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, and pentaerythritol tetrastearate (PETS)), and the like). Specifically, pentaerythritol tetrastearate (PETS) may be used.

According to a specific embodiment, the ratio (by weight) of the heat stabilizer to the release agent in the additive in the second raw material is, for example, 1: about 1-1.5, specifically 1: about 1.1 to 1.4, more specifically 1: about 1.2 to 1.3, but is not necessarily limited thereto.

According to an exemplary embodiment, the polycarbonate raw material and the polycarbonate and additive-containing raw material introduced into each of the first feeder 111 and the second feeder 112 may have various shapes, for example, pellets, flakes, granules. and the like, and in some cases, the raw material in a bulk state may be crushed in advance to be introduced into the twin-screw extruder and supplied to the feeding area. In addition, in the case of the second raw material, the polycarbonate and the additive component may be introduced separately, or the additive may be supplied in the form of being incorporated into the polycarbonate (ie, integrally combined). In addition, the size (diameter) of the polycarbonate raw material to be introduced may be, for example, about 10 to 50 mm, specifically about 5 to 30 mm, more specifically about 2 to 10. mm, but is not limited thereto. .

According to the illustrated embodiment, the weight ratio of the first raw material to the second raw material may be, for example, 1: about 0.1 to 0.5, specifically 1: about 0.2 to 0.4, more specifically 1: about 0.25 to 0.35. can

As described above, the first raw material and the second raw material introduced into the twin-screw extruder through at least a pair of main feeders in the feeding area A form a first raw material mixture in a solid state, and the introduced first raw material mixture is It moves while advancing in the die-side direction in the transfer region (B), while maintaining a solid state as a whole (it may be partially melted, but substantially moves in a solid state). To this end, in the case of the first barrel region corresponding to the transfer region B, the depth and/or width of the flight formed on the screw is relatively large.

The first raw material mixture passing through the conveying area (B) arrives at the mixing area (C), where the molten portion (second barrel area) in the mixing area is set to a higher temperature condition than that of the feeding and conveying area, as a result, the first At least a portion, specifically at least about 50%, more specifically at least about 80%, of the raw material mixture (particularly polycarbonate) may be molten, and in certain embodiments may be substantially molten. At this time, as it moves from the melting part to the first kneading block, the first mixture may be melted under pressure.

On the other hand, the first kneading block (third barrel area), for example, a kneading disk having a neutral angle, that is, a neutral kneading block (neutral kneading block) may include a bar, through this kneading process dispersive mixing ability (dispersive) While the mixing ability may be high, the distributive mixing ability may be low. As a result, the first raw material mixture has a property in which the polycarbonate is well melted in the barrel. At this time, the first kneading block is set to a lower temperature than that of the molten portion (second barrel region), which is in consideration of excessive temperature rise due to heat generation due to friction or the like during the kneading process.

Then, the first raw material mixture that has passed through the first kneading block moves to the transition section (the fourth barrel section), and through the side feeder 113 provided in the transition section, polytetrafluoroethylene (PTFE) as a third raw material ) is introduced into the barrel. In this regard, while the above-mentioned first and second feeders are gravimetric feeders, the side feeder 113 may be a volumetric feeder, and can be injected into the extruder at an accurate injection amount by a pumping method. and, in particular, may be advantageous for input in a relatively small amount.

According to an exemplary embodiment, PTFE is available from a variety of forms or sources known in the art, and may illustratively be provided in particulate form. In this regard, PTFE may be Teflon ^™ 636-N, Teflon ^™ 30J, commercially available from DuPont, Teflon ^™ 30N, FR 302 from 3F Co, JF4DC from JH Co., D2C from Daikin, etc. in the form of latex (aqueous dispersion). , but is not limited thereto. In an exemplary embodiment, the size of the PTFE particles can range, for example, from about 0.01 to 0.95 μm, specifically from about 0.05 to 0.7 μm, more specifically from about 0.1 to 0.6 μm, particularly from about 0.2 to 0.5 μm. there is. If the particle size of PTFE is too large, it may be advantageous to appropriately select within the above range as it may form an uneven surface on the resin molding when it is later introduced into the matrix resin as a flame retardant auxiliary agent (or drip prevention agent). .

In addition, the molecular weight (M _w ) of PTFE may be, for example, about 3,000,000 to 10,000,000, specifically about 4,000,000 to 8,000,000, more specifically about 5,000,000 to 7,000,000 bar, stability in the process of being introduced into the matrix resin in the future , may be determined in consideration of the flowability of the resin due to the behavior of the polymer in the compounding device.

According to an exemplary embodiment, the PTFE may be introduced into the twin screw extruder in the form of a dispersion, specifically an aqueous dispersion. As such, the reason for introducing the dispersion in the form of a dispersion is that good stability of the fine PTFE particles can be secured. Illustratively, the solids (ie, PTFE) content in the dispersion is, for example, from about 40 to 75% by weight, specifically from about 50 to 70% by weight, more specifically from about 56 to 64% by weight, particularly from about 58 to 62% by weight. In order to provide such a dispersion, a commercially available latex product may be used, and alternatively, it may be prepared by dispersing PTFE in powder form in an aqueous medium using a mixer (eg, a static mixer). In this regard, commercially available latex type PTFE can be used, and when it exceeds the above-mentioned solid content range, it can be adjusted to have an appropriate solid content by adding more water.

According to an exemplary embodiment, the dispersion of PTFE particles introduced into the side feeder 113 is introduced at a predetermined temperature, for example, about 20 to 40° C., specifically about 22 to 30° C., more specifically about 23 to 25° C. can be The above-mentioned temperature range can be understood for the above-mentioned purpose.

Meanwhile, the injection amount of PTFE may be determined in consideration of the concentration and pumping ability of the PTFE dispersion. Illustratively, the weight ratio of polycarbonate (PC): polytetrafluoroethylene (PTFE) in the total raw material supplied to the twin-screw compressor is, for example, 1: about 0.6 to 1.5, specifically 1: about 0.8 to 1.3, More specifically, 1: may be set in the range of about 0.9 to 1.1.

As such, the first raw material mixture is combined and mixed with the PTFE supplied through the side feeder 113 at the transition portion to form the second raw material mixture. At this time, the transition part is set to a higher temperature than that of the first kneading block, which maintains a molten state when the liquid medium (specifically, water) and the first raw material mixture come into contact when the third raw material, PTFE, is introduced in the form of latex. because it is preferable to

The second raw material mixture formed as described above moves to the melt in a relatively unpressurized state in the first half (specifically, the fifth barrel zone) while passing through the moving part, and in the second part, the second kneading block (the seventh barrel zone) As it approaches, it moves under pressure.

According to an exemplary embodiment, a first vent hole 114 may be provided in the moving part, specifically, in the fifth barrel region. The first vent hole 114 is provided for the purpose of continuously or discontinuously removing air introduced into the barrel, water vapor, water vapor generated in the melting and kneading process, and/or gaseous components decomposed under high temperature. For example, hydrolysis of polycarbonate can be prevented by removing moisture, and air trapped in the raw material acts as a factor to reduce the capacity of the twin screw extruder, so it is advantageous to remove it. According to an exemplary embodiment, as illustrated, a vacuum may be applied to the first vent hole to increase the venting effect.

In addition, as described above, the moving parts (fifth and sixth barrel regions) are set at a relatively higher level than the temperature (T) of the transition part (fourth barrel region), which is the result of polycarbonate incorporating PTFE. This is because it is advantageous to quickly move the inner space of the barrel in the die-side direction while maintaining the molten state.

After that, the second raw material mixture that has passed through the moving unit is again subjected to a kneading process in the second kneading block (seventh barrel area), in which case the second kneading block may include a neutral kneading block similar to that in the first kneading block, , may further include a kneading block having a positive angle and / or a kneading block having a negative angle additionally. In the illustrated embodiment, the second raw material mixture is completely mixed or kneaded in a substantially molten state while passing through the second kneading block, and as described above, it can be processed at a higher temperature than the temperature (T) of the transition part. . At this time, the reason why the temperature of the second kneading block is higher than the temperature of the previous first kneading block is to maintain the polymer in a molten state.

Subsequently, the second raw material mixture in the molten state passes through the processing region D, that is, the eighth and ninth barrel regions, and a second vent hole 115 is installed in the eighth barrel region, which is the first half of the processing region. As a result, gaseous components such as decomposition components, volatile components, and water vapor generated during the kneading process can be discharged, and further, air that may be contained in the molten mixture can be removed. In addition, a vacuum may be applied to the second vent hole 115 in order to increase the venting effect. At this time, when the second raw material mixture in the molten state reaches the processing region, it moves in an unpressurized state in the first half (specifically, the eighth barrel region) and moves under pressure in the second half (specifically, the ninth barrel region). , it is desirable to provide the necessary pressure (ie, pressurized) to effect the extrusion, particularly in a die located downstream of the processing region.

In this way, in the processing region, the second raw material mixture is transferred to the barrel end while maintaining a molten state, and is extruded through the die E connected to (communicating with) the barrel end. At this time, the temperature of the die can be maintained at an appropriate temperature to enable smooth extrusion, for example, about 60 to 100 ° C, specifically about 70 to 80 ° C, more specifically about 75 to 85 ° C. can The extrudate may also be, for example, in the form of a strand.

As described above, since the extrudate of the second raw material mixture discharged through the die is still in a high temperature state, it undergoes a cooling step in order to prepare a master batch therefrom. At this time, a cooling bath (F), more typically a cooling bath containing water (ie, a water bath) may be used, and the cooling temperature is, for example, about 30 to 60° C., specifically about 35 to 55° C., more specifically It can be adjusted in the range of about 40 to 50 ℃. When the cooling temperature is too low, the extrudate is rapidly hardened and difficult to cut, or may exhibit undesirable properties and shapes, and it is necessary to remove moisture attached to the surface while passing through a cooling bath.

As described above, the cooled extrudate may be cut into a desired shape and/or dimension by a cutter (G) to obtain a master batch type additive. In this case, the cutter may be, for example, a pelletizer. In addition, the shape of the cut product may be spherical, granular, pellet, etc., and the size (diameter) is, for example, about 10 to 60 mm, specifically about 20 to 50 mm, more specifically about 30 to 40 mm range, but this may be understood as illustrative. Such a master batch type additive is typically in the form in which PTFE is dispersed in a carbonate resin.

Optionally, a drying step may be performed before or after cutting, because polycarbonate has a moisture absorption property and, if left naturally, the moisture content in the master batch may increase. To this end, a dehumidifying type dryer may be used, and it may be advantageous to store or store after lowering the final moisture content in the master batch to, for example, about 0.1% or less, specifically, about 0.05% or less.

In an exemplary embodiment, the bulk density of the master batch can be, for example, in the range of about 700 to 900 g/cm 3 , specifically about 750 to 850 g/cm 3 , and more specifically about 780 to 800 g/cm 3 , Also, the specific gravity thereof may be, for example, about 1.2 to 1.4, specifically about 1.25 to 1.35. The above-described physical properties may be understood as illustrative.

Polycarbonate-based resin composition

According to another embodiment of the present disclosure, the previously prepared master batch may be applied to an engineering plastic, specifically a polycarbonate-based resin or a blend of a polycarbonate-based resin and another resin, as a flame retardant auxiliary agent or an anti-drip agent.

As described above, since a master batch type additive is used in which polycarbonate, which is the same material as the matrix resin, is combined with PTFE, the main component that provides an anti-drip effect, not only provides good compatibility but also reduces the flowability of the matrix resin. It provides the advantage that it does not. As a result, the polycarbonate-based resin composition into which the anti-drip agent according to the present embodiment is introduced may exhibit good surface quality as well as improved anti-drip ability.

In this regard, the polycarbonate-based resin as a matrix for forming the molded article may be prepared through an interfacial polymerization process between dihydric phenol and phosgene, a melt-esterification process from bisphenols and carbonate ester, and the like. According to an exemplary embodiment, the molecular weight (M _w ) of the polycarbonate-based resin is, for example, about 7,000 to 40,000, specifically, about 8,000 to 35,000, more specifically, about 9,000 to 33,000, in consideration of applicability to the manufacture of large-sized injection moldings. can be a range.

On the other hand, examples of the polycarbonate-based resin and blendable resin include a styrene-based resin (eg, polystyrene (specifically, high-impact polystyrene (HIPS), (meth) acrylic acid ester / styrene copolymer, acrylonitrile / styrene copolymer, Styrene/maleic anhydride copolymer, ABS, ASA, AES, etc.), acrylic resin (eg, polymethyl methacrylate (PMMA), etc.), polyamide-based resin, polyester-based resin (eg, polyethylene terephthalate) phthalate (PET), polybutylene terephthalate (PBT), etc.), polysulfone-based resin, polyarylate-based resin, polyphenylene sulfide-based resin, thermoplastic urethane resin, polyolefin-based resin (e.g., polyethylene, polypropylene, polybutylene, ethylene/propylene copolymer, ethylene/butylene copolymer, etc.), copolymers of alpha-olefins with other comonomers (e.g., ethylene/vinyl acetate copolymers, ethylene/(meth)acrylic acid ester copolymers) , ethylene/maleic anhydride copolymer, and ethylene/acrylic acid copolymer), etc. The content of the polycarbonate-based resin in the blend of these polycarbonate-based resins (based on the total polymer component) is, for example, at least about 30% by weight , specifically about 35 to 90% by weight, more specifically about 40 to 80% by weight, and particularly specifically about 50 to 70% by weight. there is.

In addition, the master batch type anti-drip agent according to this embodiment is a matrix polycarbonate or a blend thereof when the high viscosity specification (for example, about 3 to 10 g / 10 min, specifically about 4 to 8 g / 10 min of melt index), for medium viscosity specifications (eg, a melt index of about 10 to 20 g/10 min, specifically about 12 to 16 g/10 min), and for low viscosity specifications (eg, about melt index of 20 to 30 g/10 min, specifically about 22 to 26 g/10 min).

On the other hand, in the polycarbonate-based resin composition according to this embodiment, the above-described master batch type flame retardant auxiliary agent (drip prevention agent) is based on 100 parts by weight of a polycarbonate-based resin or polycarbonate-based resin blend as a matrix resin, for example, It may be defined in the range of about 0.1 to 1 part by weight, specifically about 0.3 to 0.8 part by weight, and more specifically about 0.5 to 0.7 part by weight. When the content of the flame retardant auxiliary agent is too small, it is difficult to achieve a desired anti-drip effect, whereas when the content is too large, surface quality problems may be induced. Therefore, it may be advantageous to appropriately adjust and use within the above-described range.

In addition, according to one embodiment, it may contain a flame retardant for imparting main flame retardancy to the resin composition together with the master batch type flame retardant auxiliary agent. In this regard, as the flame retardant, a flame retardant component known in the art, for example, at least one selected from the group consisting of organic salt-based flame retardants, halogen-based aromatic flame retardants and aromatic phosphate-based flame retardants may be used.

According to an exemplary embodiment, the organic salt may be an alkyl sulfate (or sulfonate) salt, an alkyl phosphate salt, etc, for example sodium hexadecyl sulfate, potassium hexadecyl sulfate, potassium perfluorobutanesulfonate, dipotassium Diphenylsulfone-3,3-disulfonate, potassium 2,4,5-trichlorobenzenesulfonate, potassium diphenylphosphate, sodium diphenylphosphate, potassium bis(2,6-dibromo-4-cumylphenyl) ) phosphate, sodium bis (4-cumylphenyl) phosphate, potassium bis (4-bromophenyl) phosphate, potassium bis (2,4-dibromophenyl) phosphate, potassium bis (2,4,6-tribromo) Phenyl) phosphate, potassium perfluorobutane sulfate, potassium bis (p-toluenesulfone) imide, sodium lauryl sulfate, potassium lauryl sulfate, etc. can be used in combination of one or two or more.

According to an exemplary embodiment, examples of the halogen-based aromatic flame retardant include 2,2-bis-(3,5-dichlorophenyl)-propane, bis-2(2-chlorophenyl)-methane, bis(2,6- Dibropophenyl)-methane, 1,1-bis-(4-iodophenyl)-ethane, 1,2-bis-(2,6-dichlorophenyl)-ethane, 1,1-bis-(2- Chloro-4-iodophenyl) ethane, 1,1-bis- (2-chloro-4-methylphenyl) -ethane, 1,1-bis- (3,5-dichlorophenyl) -ethane, 2,2-bis -(3-phenyl-4-bromophenyl)-ethane, 2,6-bis-(4,6-dichloronaphthyl)-propane, 2,2-bis-(2,6-dichlorophenyl)-pentane, 2,2-bis-(3,5-dibromophenyl)-hexane, bis-(4-chlorophenyl)-phenyl-methane, bis-(4-hydroxy-2,6-dichloro-3-methoxy One or two or more of phenyl)-methane, 2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane, tris(4-bromophenyl) phosphate, and the like may be used in combination.

According to an exemplary embodiment, the aromatic phosphate-based flame retardant is: For example, phenyl bis (dodecyl) phosphate, phenyl bis (neopentyl) phosphate, phenyl bis (3,5,5'-trimethylhexyl) phosphate, ethyl diphenyl phosphate, 2-ethylhexyl di (p-tolyl) phosphate , bis(2-ethylhexyl)p-tolyl phosphate, tritolyl phosphate, bis(2-ethylhexyl)phenyl phosphate, tri(nonylphenyl)phosphate, bis(dodecyl)p-tolyl phosphate, dibutyl phenyl phosphate, 2 -Chloroethyl diphenyl phosphate, p-tolyl bis (2,5,5'-tylmethylhexyl) phosphate, 2-ethylhexyl diphenyl phosphate, resorcinol bis phosphate, hydroquinone bis (disylenyl phosphate), tris (2,4,6-xylyl)phosphate and the like can be used in combination of 1 or 2 or more.

According to an exemplary embodiment, the flame retardant is, based on 100 parts by weight of the polycarbonate-based resin or polycarbonate-based resin blend, for example, about 0.5 to 20 parts by weight, specifically about 0.7 to 10 parts by weight, more specifically about 0.9 to 3 parts by weight. At this time, when the content of the flame retardant is too low, the UL94 flame retardant standard performance failure phenomenon occurs, whereas when the content is too high, a problem of cost increase may be induced. Therefore, it may be advantageous to appropriately adjust within the above-mentioned range.

According to an exemplary embodiment, the polycarbonate resin composition may further include a combination of one or two or more of various additives known in the art. Examples of such additives are dispersants, processing stabilizers, heat stabilizers, antioxidants, plasticizers, antistatic agents, mold release agents, UV stabilizers, lubricants, pigments, dyes, flow enhancers, antifogging agents, antibacterial agents, antistatic agents, conductivity imparting agents, surfactants, It may be a nucleating agent or the like. As an example, the above-described additive contains up to about 1 part by weight, specifically up to about 0.5 parts by weight, more specifically up to about 0.3 parts by weight, based on 100 parts by weight of the polycarbonate-based resin or polycarbonate-based resin-based blend. can be

Meanwhile, according to an exemplary embodiment, the polycarbonate-based resin composition may be prepared using a method known in the art, for example, a compounding (specifically, melt compounding) apparatus. Such compounding devices may include single screw, twin or more multi-screw, co-rotation or counter-rotating screw, reciprocating screw, pinned screw, pinned barrel, roll, ram, spiral rotor, or any combination thereof. may include As an example, the compounding apparatus may be, for example, a Henschel mixer, a Banbury mixer, a Ross mixer, a drum tumbler, a single-screw extruder, a double-screw extruder, a multi-screw extruder, a kneader, etc. can According to certain embodiments, using a twin-screw extruder as a compounding device may be advantageous in increasing the dispersing power of the polymeric resin.

In addition, the polycarbonate-based resin or a blend thereof may be introduced into the compounding apparatus in the form of, for example, granules, granules, pellets, powders, and the like. In this regard, the compounding temperature may be determined in consideration of the optimal behavior of the polymer resin, for example, about 200 to 400 ℃, specifically about 230 to 350 ℃, more specifically about 250 to 300 ℃ in the range may be determined, but this may be understood as an example.

On the other hand, the polycarbonate-based resin composition according to this embodiment may exhibit a V-0 flame retardancy rating measured by UL94, and also various types of spots (black spots) mainly used as a measure of surface defects after injection molding of molded products. , white points and blue points) may be at a significantly lower level in the degree of surface defects by discrimination, and more specifically, these spots may not be substantially contained.

In addition, the polycarbonate-based resin composition according to this embodiment has a melt index (300° C., 1.2 kg) measured according to ASTM D1238, for example, about 5 to 30 g/10 min, specifically about 6 to 25 g/ 10 minutes, specifically about 7 to 23 g/10 minutes. In addition, the heat deflection temperature measured according to ASTM D648 may be, for example, at least about 250 °C, specifically at least about 270 °C, and more specifically about 280 to 300 °C. In particular, as a result of improved compatibility due to the use of a flame retardant auxiliary agent containing the same component as the matrix, compared to the case of using a PTFE-based anti-drip agent prepared by a conventional chemical method, typically SAN-encapsulated PTFE particles, It is worth noting that it exhibits good mechanical properties. According to an exemplary embodiment, this polycarbonate-based resin composition may satisfy the following physical properties (eg, at least one of the described physical properties (i) to (iii), specifically physical properties (i) to (iii) ) is satisfied):

(i) Elongation and Tensile Strength (ASTM D638): each at least about 70% (specifically at least about 80%, more specifically about 85-95%) and at least about 7500 psi (specifically at least 7800 psi, more specifically at least about 7800 psi, more specifically) about 8000 psi);

(ii) Flexural Strength and Flexural Modulus (ASTM D790): at least about 13500 psi (specifically about 14000 psi, more specifically about 14200 to 15000 psi) and at least about 350000 psi (specifically at least about 355000 psi, more specifically about 355000 psi), respectively about 358000 to 400000 psi);

(iii) Impact strength (ASTM D256): at least about 9 Ft-lb/in (specifically about 10 Ft-lb/in, more specifically about 11 to 15 Ft-lb/in).

On the other hand, the above-described polycarbonate-based resin composition can be cut into a pellet shape in consideration of processing convenience, etc., the size (diameter) of these pellets is, for example, about 20 to 60 mm, specifically about 30 to 55 mm , more specifically adjustable in the range of about 40 to 50 mm. In addition, the polycarbonate-based resin composition may be prepared as a molding in a manner known in the art, wherein the applicable molding technique may be, for example, injection molding, extrusion, blow molding, etc., and the manufactured molding is a film, It may be a disk, an exterior material of various electronic products, an exterior product of an automobile electric product, a battery case of an electric vehicle, an electric structure, and the like.

Hereinafter, preferred examples are presented to help the understanding of the present invention, but the following examples are provided for easier understanding of the present invention, and the present invention is not limited thereto.

Preparation Example 1

A master batch type anti-drip agent was prepared using a reverse rotation twin-screw extruder (capacity 70 (mm); power requirement: 150-350 kW; material: SUS 304) having the detailed specifications shown in FIG. 1 . At this time, the temperature profile from the first barrel section to the ninth barrel section in the twin-screw extruder was set as shown in Table 1 below.

barrel area Temperature (℃) One 200-210 2 230-250 3 200-210 4 230-250 5 240-260 6 240-260 7 240-260 8 240-260 9 240-260

In addition, the temperature of the die disposed at the end of the barrel was set to 80 ℃, and the temperature of the cooling bath for cooling the extrudate discharged to the die was set to 40 ℃.

The screw of the twin-screw extruder was operated to rotate at a speed of 400 rpm, and polycarbonate (Sabic. Corporation, molecular weight (M _w ): 18000, melt index: 14 g/10min) was supplied as a first raw material through the first feeder. . In addition, polycarbonate (Sabic., molecular weight (M _w ): 18000., melt index: 14 g/10 min) as a second raw material through the second feeder: the weight ratio of the additive component is 1: 0.3 (w/w) combination was used. At this time, as an additive component, a heat stabilizer (product name: Songnox 2112) and a release agent (product name PETS..., pentaerythritol tetrastearate) were 1 ; It was used in combination in a weight ratio of 1.3. In addition, the weight ratio of the first raw material: the second raw material was adjusted to 1:0.2 and supplied to the twin-screw extruder.

In addition, PTFE latex (solid content: 60 wt%; molecular weight (M _w ): 4,500,000, particle size: 0.5 μm) was used as a third raw material through the side feeder installed in the transition part of the mixing area, at this time the temperature of the PTFE latex was added in a state controlled at 25 °C. The input amount of PTFE was adjusted to have the same weight as the polycarbonate in the first raw material and the second raw material. In addition, a vent hole was installed in each of the fifth barrel section and the eighth barrel section of the mixing area and a vacuum was applied to remove air, water vapor and light gas introduced during the extrusion process.

The second raw material mixture exited the extrudate from the die through the processing zone in molten state. At this time, the extrudate was in the form of a strand, and the size (diameter) thereof was 30 mm. Then, the extrudate was cooled in a cooling bath, and cut to have a pellet shape using a pelletizer. At this time, the size (diameter) of the cut product was 20 mm. The water content in the cut product was adjusted to 0.1% or less by using a dryer for the purpose of removing the moisture remaining in the cut product thus obtained.

Comparative Preparation Example 1

PTFE latex (solid content: 60% by weight; molecular weight (M _w ): 3,500,000, particle size: 0.5 μm):distilled water (pure grade) was introduced into a stainless steel reactor of SUS304 in a weight ratio of 1:2. 350 g of SM (Styrene Monomer) (Dongbu Hannong Chemical) 50 g AN (Acrylo nitrile) (LG Chemical) was put into the reactor, and then the temperature was raised to 50 °C at a rate of 1 °C / min. At this time, 0.15 g of an initiator, 75% BPO (Hansol Chemical) was added and stirred at 80 rpm. Thereafter, the inside of the reactor was heated to 85° C. at a rate of 10° C./min to stabilize it, and finally 1,000 g of an aqueous PTFE dispersion having a solid content of 60 wt % in the dispersion was prepared.

After 0.15 g of a dispersant (polyvinyl alcohol; VAM, Japan; molecular weight (M _w ): 105,000) was added, the reaction was stabilized under stirring (80 rpm) for about 8 hours while stabilizing at 100 ° C (second stabilization step). . When the stabilization aging process was completed, the inside of the reactor was cooled to room temperature, the lower jacket of the reactor was opened, and the contents of the paste were taken out and cooled with cooling water.

Then, the cooled product was washed several times with cooling water and then dried at 100° C. for 8 hours using a hot air dryer to lower the moisture content to 0.5 wt % or less. Subsequently, the obtained dry matter was pulverized by a roller mill for 5 minutes to finally obtain encapsulated PTFE particles having a size (diameter) of 0.8 μm.

Examples and Comparative Examples

Using each of the encapsulated PTFE particles (Example 1) prepared according to Preparation Example 1, the encapsulated PTFE particles prepared according to Comparative Preparation Example 1 (Comparative Example 1), and the PTFE particles (Comparative Example 2) as a flame retardant aid, the following table By compounding with the composition according to 2, a polycarbonate-based resin composition was prepared.

PC Flame Retardant ⁴ release agent ⁵ heat stabilizer ⁶ production example
One
comparison
Preparation Example 1 PTFE low viscosity ¹ midpoint ² high viscosity ³ Example 1 100 10 0.2 0.2 0.2 Example 2 100 10 0.2 0.2 0.3 Example 3 100 10 0.2 0.2 0.4 Example 4 100 10 0.2 0.2 0.5 Example 5 100 10 0.2 0.2 0.2 Example 6 100 10 0.2 0.2 0.3 Example 7 100 10 0.2 0.2 0.4 Example 8 100 10 0.2 0.2 0.5 Example 9 100 10 0.2 0.2 0.2 Example 10 100 10 0.2 0.2 0.3 Example 11 100 10 0.2 0.2 0.4 Example 12 100 10 0.2 0.2 0.5 Comparative Example 1 100 10 0.2 0.2 0.2 Comparative Example 2 100 10 0.2 0.2 0.3 Comparative Example 3 100 10 0.2 0.2 0.4 Comparative Example 4 100 10 0.2 0.2 0.5 Comparative Example 5 100 10 0.2 0.2 0.2 Comparative Example 6 100 10 0.2 0.2 0.3 Comparative Example 7 100 10 0.2 0.2 0.4 Comparative Example 8 100 10 0.2 0.2 0.5

¹ : PC 2200 (Sabic Corporation; MI: 22 g/10min)

² : PC 1400 (Sabic, MI: .14 g/10min)

³ : PC 101 (Sabic Corporation; MI: 7 g/10min)

⁴ : triphenyl phosphate (TPP)

⁵ : pentaerythritol tetrastearate (PETS)

⁶ : Songwon 1076 (Songwon Industrial)

In addition, the melt index, mechanical properties (tensile strength, elongation, flexural strength, flexural modulus and impact strength) and heat resistance (thermal deformation temperature) of the polycarbonate-based resin compositions prepared in Examples 1 to 12 and Comparative Examples 1 to 8, respectively ) was evaluated and shown in Table 3 below.

melt
jisoo elongation Seal
burglar curve
burglar curve
modulus of elasticity Shock
burglar heat deflection temperature unit g/10min % Psi Psi Psi Ft-lb/in ℃ measurement method ASTM D1238 ASTM D638 ASTM D638 ASTM D790 ASTM D790 ASTM D256 ASTM D648 Measuring conditions 300℃/1.2kgf Break Type I, 0.125“ type I ,0.125“ 0.125" 0.125" 0.125“ (room temperature) 66 Psi, 0.250“ Example 1 23 90 8000 14000 390100 12.5 281 Example 2 21 90 8050 14000 399000 12 281 Example 3 21 90 7990 14100 389200 13 280 Example 4 23 90 8005 14100 388000 12.5 280 Example 5 15 95 8000 14200 380100 14.,5 285 Example 6 14 95 8050 14200 380000 14 284 Example 7 14 95 8000 14100 380200 15 285 Example 8 15 95 8000 14200 380000 15.5 285 Example 9 9 85 8005 14200 380100 18 284 Example 10 8 85 8000 14200 380000 17 290 Example 11 8 85 8005 14200 380000 17 291 Example 12 8 85 8000 14200 380000 18 290 Comparative Example 1 16 70 7550 13500 340100 10 265 Comparative Example 2 17 70 7560 13600 350500 10 273 Comparative Example 3 16 70 7450 13600 351000 8 272 Comparative Example 4 18 70 7500 13650 352000 8 275 Comparative Example 5 16 75 7500 13500 341000 11 268 Comparative Example 6 15 75 7450 13500 342000 10 273 Comparative Example 7 17 75 7550 13600 342000 9 274 Comparative Example 8 16 75 7500 13650 352000 8 275

According to the table above, when using a PC/PTFE master batch prepared using a twin-screw extruder as a flame retardant aid in a polycarbonate resin, which is a matrix resin (Example 1), when the PTFE particles were encapsulated with a SAN coating layer in the past (Comparative Example) 1) and showed improved results in mechanical strength and heat resistance compared to the case of using PTFE particles alone without a coating layer (Comparative Example 2), which is a result of using a master batch using the same resin as the matrix resin, It can be considered because it has good compatibility with

On the other hand, in order to evaluate the flame retardancy and drip prevention ability, Examples 1 to 12, and Comparative Examples 1 to 8, respectively, using the polycarbonate-based resin composition prepared in each of the resin films having a thickness of 1.6 mm were prepared. For the resin film thus prepared, the flame retardancy was evaluated according to UL 94 (flame height: 20 mm, inversion time: 1st and 2nd, respectively, 10 seconds). The results are shown in Table 4 below.

flame retardant test Total burning time (s) Flame retardancy Example 1 11 V-0 Example 2 11 V-0 Example 3 12 V-0 Example 4 12 V-0 Example 5 11 V-0 Example 6 11 V-0 Example 7 10 V-0 Example 8 11 V-0 Example 9 9 V-0 Example 10 10 V-0 Example 11 9 V-0 Example 12 10 V-0 Comparative Example 1 18 V-0 Comparative Example 2 16 V-0 Comparative Example 3 16 V-0 Comparative Example 4 18 V-0 Comparative Example 5 18 V-0 Comparative Example 6 17 V-0 Comparative Example 7 18 V-0 Comparative Example 8 18 V-0

According to the table above, the polycarbonate resin compositions (Examples 1 to 12) using PC/PTFE master batches as anti-drip agents were PTFE particles (Comparative Examples 1 to 4) and PTFE particles (Comparative Examples 5 to 8) encapsulated with a SAN coating layer. ), compared to the case of using, showed more improved flame retardancy and drip prevention ability.

- The surface quality of the molding was observed under a microscope (20 magnification) for each of Example 8 and Comparative Example 4 using a surface monitoring system, and the results are shown in FIG. 2 .

From the above observation results, when using a PC/PTFE master batch as an anti-drip agent according to Example 8. It was confirmed that the mechanical properties and drip prevention effect of the polycarbonate-based resin, as well as good surface quality, could be provided at the same time.

All simple modifications or changes of the present invention fall within the scope of the present invention, and the specific scope of protection of the present invention will be made clear by the appended claims.

Claims (7)

a) according to the direction of movement of the raw material, (i) a main feeder including a first feeder and a second feeder for introducing the raw material into the barrel having a length (L)/diameter (D) ratio of 20 to 36 A feeding area, (ii) a transfer area of the introduced raw material, (iii) a melting section, a first kneading block, a transition element provided with at least one side feeder, a moving section, and a second kneading block are sequentially performed providing a twin screw extruder comprising a mixing zone comprising: (iv) a processing zone for extruding raw material passing through said mixing zone in a die direction, wherein each of said first and second feeders is a gravimetric feeder;
b) introducing a combination of a first raw material polycarbonate and a second raw material polycarbonate and an additive through the first feeder into the barrel of a twin-screw extruder to form a first raw material mixture, the The first raw material and the second raw material are each in a solid form, and the second raw material is (i) 60 to 90 wt% of polycarbonate, and (ii) at least one additive selected from the group consisting of a heat stabilizer and a mold release agent 10 to 40% by weight;
c) conveying the introduced first raw material mixture in a die-side direction in a conveying area;
d) The first raw material mixture that has passed through the transfer region is transferred to the mixing region, and a third raw material containing polytetrafluoroethylene is introduced through the side feeder along with it and melted and kneaded in the mixing region to form a molten material. forming a second raw material mixture, wherein the side feeder is a positive displacement feeder;
e) transferring the second raw material mixture that has passed through the mixing region in the processing region to the barrel end while maintaining a molten state;
f) discharging the second raw material mixture that has passed through the processing region into an extrudate by means of a die; and
g) cooling the discharged extrudate and then cutting it into a desired shape and/or dimension;
includes,
Based on the barrel, the ratio (length) of the feeding area and the conveying area: the mixing area: the processing area is in the range of 1: 3 to 25: 1 to 15,
The weight ratio of the first raw material introduced from the feeding area to the second raw material is 1: 0.1 to 0.5, and the weight ratio of polycarbonate: polytetrafluoroethylene in the total raw material supplied to the twin-screw extruder is 1: It is determined in the range of 0.6 to 1.5,
Based on the temperature (T) of the transition part provided with the side feeder in the mixing area, the temperature of each of the first kneading block and the second kneading block is 25 to 50°C lower than T, and 5 to 30°C higher than T range, the temperature of the melting section is set within the range of T, the temperature of the moving section is set in the range of 5 to 30 ℃ higher than T, and the temperature of the feeding zone and the transfer zone is 25 to 50 ℃ lower than T A method for producing a drip preventing agent for a polycarbonate-based resin of a master batch type, which is determined in the range, and the temperature of the processing region is 5 to 30° C. higher than T. The method according to claim 1, further comprising a first vent hole in the moving part, and the step of degassing the gas contained in the second raw material mixture through the first vent hole is performed, and
A second vent hole is further provided in the processing region, and the step of degassing the gas contained in the second raw material mixture through the second vent hole is performed. A method for manufacturing an anti-drip agent. The method according to claim 1, wherein the polycarbonate in the first raw material and the second raw material has a melt index (300° C., 1.2 kg) in the range of 8 to 20 g/10 min, measured according to ASTM D1238, and
Polytetrafluoroethylene in the third raw material has a particle diameter in the range of 0.01 to 0.95 μm and a molecular weight (M _w ) in the range of 3,000,000 to 10,000,000. Method for producing a master batch type polycarbonate-based anti-drip agent for resin . [Claim 4] The method according to claim 3, wherein the temperature (T) of the transition part is set at 240 to 260 °C. delete 100 parts by weight of polycarbonate-based resin or polycarbonate-based resin-based blend;
0.5 to 20 parts by weight of a flame retardant; and
A master batch type anti-drip agent prepared according to any one of claims 1 to 4, 0.1 to 1 part by weight;
A polycarbonate-based resin composition having improved anti-drip properties and flame retardancy comprising a. The polycarbonate-based resin composition according to claim 6, wherein the polycarbonate-based resin composition satisfies the following physical properties:
(i) Elongation and Tensile Strength (ASTM D638): at least 70% and at least 7500 psi, respectively;
(ii) flexural strength and flexural modulus (ASTM D790): at least 13500 psi and at least 350000 psi, respectively;
(iii) Impact strength (ASTM D256): at least 9 Ft-lb/in.

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