KR100220617B1 - Polystyrene resin composition, flame-retardant composition thereof and methods for preparation thereof - Google Patents

Abstract

The present invention (A) homo- or copolymer of styrene and styrene derivatives or rubber-modified resin 45 to 95% by weight thereof; (B) 4 to 40% by weight of the modified polyolefin copolymer alone or in admixture with other olefinic polymers prepared in the presence of a metallocene catalyst; (C) 1 to 15% by weight of at least one block copolymer of polystyrene and polyolefin, in which one or two or more polystyrene blocks are divided by one or two polyolefin blocks, optionally (D) a flame retardant Selected from the group consisting of lubricants, heat improvers, plasticizers, light stabilizers, antioxidants, release agents, antistatic agents, conductive additives, impact modifiers, colorants (dyes or pigments), glass fibers, foaming agents, organic or inorganic fillers It relates to a polystyrene-based resin composition comprising at least one additive. The polystyrene resin composition according to the present invention can be produced in the form of a blend or a polymerization product by a blending method using a conventional kneading extrusion device or by a bulk or bulk-suspension polymerization using a HIPS polymerization reaction facility. The polystyrene-based resin composition according to the present invention provides high impact strength and tensile strength and excellent weather resistance, chemical resistance and gloss, and thus is excellent in application to non-flammable and flame-retardant injection molded articles. Widely available.

Description

Polystyrene-based resin composition, flame retardant composition thereof and method for producing the same

The present invention relates to a highly functionalized polystyrene resin composition, a flame retardant composition thereof and a method for preparing the same, and more particularly, to a homo or copolymer of styrene and a styrene derivative or a composition of a rubber-modified resin and a modified polyolefin thereof. (Stiffness or Rigidity) and the toughness (Toughness) of the balance is very excellent, high weatherability (Weatherability), high gloss (Gloss), chemical resistance (Chemical resistance) properties and the physical properties are very small A flame retardant composition having excellent weatherability and flame retardant properties, and a method for preparing each thereof.

Polystyrene resin, which is a thermoplastic resin, is widely used in various industrial fields such as daily necessities, electrical and electronic products, packaging materials, and building materials because of excellent molding processability. Such polystyrene resins include general-purpose polystyrene (GPPS) having excellent transparency and rigidity, and impact-resistant polystyrene resin (HIPS) which compensates for its fragile disadvantages by introducing elastomers such as polybutadiene, styrene-butadiene copolymer rubber and the like. The styrene resin by copolymerization and blend of SMA, SAN, ABS, ABS / PC, ABS / PVC, AES, AAS, etc. devised to have other characteristics may be mentioned. In general, polystyrene resin refers to GPPS, a general-purpose styrene resin, and HIPS, an impact-resistant polystyrene resin. In the case of GPPS, impact strength is very low compared to tensile strength, and in the case of HIPS, impact resistance is improved, but physical properties such as stiffness and gloss are reduced. It could not be avoided and had disadvantages such as structural denaturation due to UV due to the added elastomer and impurities, property degradation and yellowing. Therefore, the scope of application is quite limited.

In order to remedy these shortcomings, various additives such as UV stabilizers, antioxidants and whiteness improvers have been introduced, along with efforts to change the structure of the main chain and the added elastomers, and to form copolymer resins with the second and third monomers. And blend compositions with polyolefins, enpra resins, and the like. In order to improve the glossiness, minimization of dispersed particle diameters has been attempted by adjusting the type of elastomer and process parameters. However, in most cases, it did not achieve a balanced satisfaction of the desired physical properties, and if the physical property balance is satisfactory to some extent, the manufacturing cost increases, which makes it difficult to commercialize.

For example, polystyrene produced by polymerizing styrene monomer in the presence of ethylene-propylene-diene terpolymer (EPDM) rubber to improve weather resistance and toughness, is expected to be effectively improved due to the small graft bonding force between EPDM rubber and styrene. In addition, the dispersion particles were enlarged (10 to 20 mu m) in size, accompanied by problems such as surface defects and gloss reduction. In addition, examples of attempting to improve physical properties by blending or adding styrene / butadiene copolymers of various structures in which a double bond of butadiene is completely or partially hydrogenated (EP 4,685; 250,970; DE 2,839,357; US 3,810,957, etc.) In order to show the required impact strength, a large amount of expensive styrene / butadiene copolymer has to be added, and there are problems in economics and manufacturing process, and other physical properties such as tensile strength decrease in proportion to the increase in impact strength. There are disadvantages.

On the other hand, as another method using blending, a method of blending a polyolefin class such as polyethylene or polypropylene in the presence of polystyrene and various kinds of compatibilizers has been reported. (US 3,810,957; 4,429,323; 4,560,727; 5,278,232; 5,344,869; EP 60,524; 125,227; 310,051; 329,283; 402,340; 421,359; DE 2,839,357 etc.) Compared with the improvement of impact resistance, the physical properties such as poor rigidity are not balanced, and the physical properties such as glossiness and flowability are not easily adjusted, and the physical properties are not stable in various applications due to the introduction of other special additives. In the case of compositions which are currently being commercialized in such products, most of them are developed for use in films (US 902,718; 5,344,714; 5,258,463, etc.) or for adhesion in view of such deterioration of properties. (US 4,560,727; 5,278,232; 5,344,869, etc.), the mechanical strengths such as tensile strength and flexural strength were also lowered (polystyrene was 25 to 55 N / mm ^{2 for} yield stress, while the blends had 11.5 to 26.9 N / mm ² ) is very large and the increase in impact strength is insignificant, and it does not impart properties such as gloss and flame retardancy.

Looking at the development of such a series of polystyrene-based resin composition, in the general-purpose polystyrene (GPPS), which is transparent, high gloss, excellent in rigidity but very poor in impact resistance, transparency is excluded by addition of elastomers such as various rubbers. The first change can be seen in the impact-resistant polystyrene (HIPS), which has improved impact resistance and elongation characteristics, but has poor weather resistance and is inferior in stiffness and gloss. Next, we will look at a number of improvements to overcome the disadvantages of gloss, transparency, stiffness, heat resistance and weather resistance, such as the disadvantages of such impact-resistant polystyrene. To maintain a low content, to introduce copolymerization monomers such as MMA and BA to improve transparency, to introduce rigidity and weather resistance, to introduce other special elastomers or to blend with polyolefin derivatives in the presence of various compatibilizers. The method of constructing this etc. are mentioned. However, in the case where the respective methods are applied, there has not been developed a satisfactory commercially viable method so far that can effectively improve the shortcomings of polystyrene and thus effectively improve other physical properties.

From this point of view, while satisfying both the rigidity and impact resistance of the general-purpose polystyrene at the same time, it is excellent in workability and handling, and it is easy to control other special physical properties such as gloss, weather resistance, chemical resistance, flame retardancy, There has been a demand for the development of such a polystyrene-based resin composition that can be commercialized due to its excellent manufacturing cost, which is excellent in that there are almost no deterioration of other physical properties that can occur when such property is imparted.

The present inventors have studied various combinations of matrix phases and disperse phases, compatibilizers, etc. in order to obtain a highly functionalized polystyrene resin composition that meets these needs, and thus, the present invention can be prepared in the presence of a metallocene catalyst on a suitable polystyrene resin matrix. By using a compatibilizing agent composed of a suitable amount of styrene-olefin block copolymer as a modified polyolefin-based copolymer in a dispersed phase, a blend having an effective dispersed phase and stability can be produced at low cost. In addition, a polystyrene-based polymerization product exhibiting the same excellent physical properties was obtained by mass- and mass-suspension polymerization of the above composition components using a polymerization reaction facility usually used for HIPS production. Furthermore, even when the present inventors prescribe additives for imparting various properties such as flame retardants, the physical properties were very low, and in particular, it was confirmed that physical properties of conventional flame retardant compositions were higher than those of conventional ABS resins.

Therefore, the object of the present invention is to excellently improve the various disadvantages of the conventional polystyrene-based resin and its improved product, the physical property balance of the stiffness-impact resistance is very excellent, and the control while having excellent properties of high weather resistance, high gloss It is to provide a highly functionalized polystyrene-based resin composition capable of imparting other properties such as workability, handleability, and flame retardancy, and a method for producing the same.

It is also an object of the present invention to provide a polystyrene-based resin composition and a method for producing the same, as well as having excellent properties as described above, as well as flame retardancy.

Furthermore, the object of the present invention is to use the polystyrene-based resin composition according to the present invention in many fields where the general-purpose polystyrene, impact-resistant polystyrene, polystyrene blends are difficult to use as ABS or its blends, and at a low cost. It is to manufacture a variety of molded articles.

1 is a graph showing a comparison of the Izod impact strength with the passage of time in the composition according to the present invention and the conventional resin.

Figure 2 is a graph showing a change in tensile strength over time in the composition according to the present invention and the conventional resin.

In order to achieve the above object, according to the first embodiment of the present invention,

(A) 45 to 95% by weight of homo or copolymers of styrene and styrene derivatives or rubber-modified resins thereof; (B) 4 to 40% by weight of the modified olefin copolymer alone or in admixture with other olefin polymers prepared in the presence of a metallocene catalyst; (C) A polystyrene resin composition is provided comprising 1 to 15% by weight of a block copolymer of polystyrene and polyolefin in which one or two or more polystyrene blocks are divided by one or two polyolefin blocks.

According to a second embodiment of the present invention, in addition to the components (A), (B) and (C), (D) flame retardant, lubricant, heat improver, plasticizer, light stabilizer, antioxidant, mold release agent, and charging Provided is a polystyrene resin composition further comprising at least one additive selected from the group consisting of an inhibitor, a conductive additive, an impact modifier, a colorant (dye or pigment), a glass fiber, a foaming agent, an organic or inorganic filler.

According to a third embodiment of the present invention, a polystyrene-based blend is obtained by using various kneading extrusion means for a composition comprising the components (A), (B) and (C) and optionally one or more additives of (D). It is provided a method of manufacturing.

According to the fourth embodiment of the present invention, a composition comprising mainly (A) and (B) components and containing at least one additive selected from (C) component and / or (D) using a polymerization reaction facility. A method for producing a polystyrene-based polymerization product is provided.

Moreover, according to 5th Embodiment of this invention, various molded products, such as an injection molded article and an extrusion molded article manufactured using the said polystyrene resin composition, are provided.

The polystyrene used in the composition of the present invention includes homo or copolymers of styrene and styrene derivatives and rubber modified resins thereof, and has a molecular weight in the range of 100,000 to 500,000, preferably in the range of 150,000 to 350,000. Its content is preferably 45 to 95% by weight, more preferably 60 to 85%.

As the dispersed phase, a modified polyolefin copolymer of the following Chemical Formula 1 produced by polymerization using a metallocene based single site catalyst:

[Wherein,

n and m are integers from 1 to 500,

X is hydrogen or an aromatic or aliphatic hydrocarbon from C1 to C950 or a copolymer thereof,

Y is (CH ₂ ) wCH ₃ ,

W is an integer between 0 and 1000.]

4 to 40% by weight, preferably 7 to 30% by weight, alone or in mixture with other olefinic polymers, is used with an average molecular weight (Mw) of 40,000 to 300,000. Other olefinic polymers here include polyethylenes of various structures (HDPE, LDPE, LLDPE, VLDPE, ULDPE, etc.), polypropylene, ethyl-vinyl copolymer (EVA), polyethylene-propylene (EPM) and polyethylene-propylene-diene air. Copolymer (EPDM), acrylic copolymer (EAA) and the like. In particular, as a metallocene catalyst copolymer of ethylene and other alkene compounds, it is more preferable that the alkene compound content is 5 to 50 weight%.

The styrene-olefin block copolymer is added as a compatibilizer and has one or more polystyrene blocks (S) divided by one or two polyolefin blocks (O). The form of the block copolymer has the structure of Formula 2 or 3 below.

S ₁ -O _1- (S ₂ ) _n [where n is 0 or 1]

S ₁ -O ₁ -O _2- (S ₂ ) _m [where m is an integer of 0 or greater]

The polystyrene block has a proportion of 13 to 70% by weight of the total polymer block and has a molecular weight of 5,000 to 500,000.

In particular, a block copolymer having the structure of the following Chemical Formula 3a or 3b is preferable.

S _m- (E _n -P _w ) _y -S _x

S _m- (E _n -B _w ) _y -S _x

Wherein S is a polystyrene block, EP is a polyethylene, polypropylene block, EB is a polyethylene, polybutylene block. m ranges from 30 to 350 and n and w ranges from 200 to 900. x ranges from 0 to 350. y is an integer ranging from 1 to 100. In each case, the content of the polystyrene block is 13 to 70% by weight.

The content of styrene-olefin block copolymer in the total composition is 1 to 15% by weight, more preferably 2 to 10% by weight.

Various additives can be added to the polystyrene resin composition which concerns on this invention, without accompanying physical property degradation, such as impact strength and tensile strength. Examples of additives include flame retardants, lubricants, heat improvers, plasticizers, light stabilizers, antioxidants, mold release agents, antistatic agents, conductive additives, impact modifiers, colorants (dyes or pigments), glass fibers, foaming agents, organic and inorganic fillers, and the like. Can be mentioned.

In particular, in the case of adding a flame retardant for imparting flame retardancy of the resin, even if a large amount is added, there is almost no deterioration in physical properties. The amount of flame retardant added to the composition of the present invention can be up to 5 to 35% by weight, and the amount of the flame retardant may be adjusted according to the degree of flame retardancy. In the present invention, the flame retardant is a concept including both halogen-based flame retardants and non-halogen-based flame retardants as well as flame retardants such as antimony trioxide and chlorinated polyethylene.

The composition of the present invention using a mixing means having a rotary stirring means such as ribbon blender (Ribbon Blender), V-type blender, Henschel Mixer (Henchel Mixer) and the like for several minutes at room temperature at several hundred to thousands RPM, and then It may be prepared as a blend by extruding by kneading extrusion means such as an extruder, a blower plastic order (Brabender Plasticorder), a Banbury Mixer, a Mixing Roll, a Kneader. The temperature at the time of kneading extrusion is preferably adjusted to 170 to 260 ° C and the rotational speed of the screw to 180 to 350 rpm.

In addition, it can be prepared as a polymerization reaction using a polymerization equipment for producing a conventional polystyrene resin. In the case of using the polymerization equipment, a mixed solution in which the necessary additives selected from modified polyolefins, various rubbers, additives, and the like are added together in the presence of styrene and / or derivatives thereof and other monomers copolymerizable as necessary, as in the production of HIPS. And bulk-suspend polymerization.

The polymerization reactants according to the invention have almost the same physical properties as the blends, and the control of the properties of each polymerization reaction shows a similar tendency as in conventional HIPS preparation. That is, the physical properties of the finally prepared composition may be affected by general HIPS property control variables such as the molecular weight of PS in the matrix, the presence or absence of an initiator, the type and amount of the additive, the stirring speed in the reaction process, and the temperature. Therefore, in the polymerization production process, which is one of the methods for preparing the composition of the present invention, all factors related to manufacturing HIPS may be included.

The polystyrene-based resin composition according to the present invention may be produced as non-flammable and flame-retardant injection molded articles according to a conventional molding method, and may be prepared as an extrusion molded article such as a film or sheets by appropriately blending additives.

The following examples are intended to illustrate the invention in more detail, whereby the scope of the invention is not limited.

Example 1

Component (A) is a pellet type solar polystyrene grade (Solarene polystyrene grade), Component (B) is modified by a metallocene based single site catalyst (Metallocene based single site catalyst) Modified polyolefine copolymer grade, and component (C) is a styrene-poly (ethylene-propylene) -styrene block copolymer and a styrene-poly (ethylene-butylene) -styrene block copolymer, respectively. The amount of 1 base material was used one by one (DH1-DH22).

The above components were physically mixed at 1000 rpm for 5 minutes at room temperature using a Henschel mixer, and then the mixture was screwed using a twin screw extruder (L / D = 13) in a temperature range of 170 ° C to 250 ° C. Kneading was carried out within 300 range at RPM 200, and pellets were prepared by the strand cutting method. In order to measure the mechanical properties of the prepared polystyrene blends after drying at room temperature, the test pieces were injected at the conditions of an injection molding machine at a temperature of 210 ° C., a mold temperature of 50 ° C., and a molding cycle of 35 seconds.

The tensile strength, Izod impact strength, and flexural strength of the test specimens thus prepared were measured according to ASTM D638 and ASTM D256, respectively. Glossiness was measured in accordance with ASTM D523 to prepare a specimen of diameter 56.0mm, thickness 1.6mm, using a gloss meter (Gloss Meter) at an angle of incidence of 60 degrees.

The physical properties of the specimens prepared according to the component ratio of each component by the above method are shown in Table 1.

Example 2

The flame retardant and physical properties of the blend composition exemplified in Example 1 were added as component (D) as shown in Table 2. Flame retardants of component (D) were halogen-based and non-halogen-based flame retardants. Antimony trioxide and polyethylene chloride were used as flame retardant aids. As can be seen in Table 2, even when a flame retardant is added, the polystyrene-based blend composition according to the present invention exhibits excellent physical stability in impact strength and tensile strength.

Example 3

The bulk polymerization was carried out under the same conditions as in the conventional HIPS polymerization, and the physical property analysis was performed in the same manner as in Example 1. Physical properties analysis results of the polymerization composition are shown in Examples DH23, DH24, and DH25 of Table 1a, respectively. Here, the content of component (A) represents the content of component (A) in the final polymer on the basis of the average molecular weight, respectively. From these results, the polystyrene-based resin composition according to the present invention can be produced using a kneading extrusion device in the production method thereof, as well as styrene or its derivatives in the presence of components (B), (C) and (D). And other copolymerizable monomers can be prepared using conventional polystyrene polymerization reactors.

Comparative Example 1

As shown in Table 3, a single high density polyethylene (HDPE) and linear low density polyethylene (LLDPE) as pelletized component (A) and component (B) as component (A) Using the crosslinked copolymer of polystyrene and olefin as component (C), a blend was prepared in the same manner as in Example 1. The physical properties of the prepared blends were measured by the method as shown in Example 1, and the results are shown in Table 3, and it is understood that the physical properties were not balanced unlike the results shown in Example 1.

The weather resistance was tested for the blends (DH4, DH9, DH12) prepared in Example 1. The weather resistance test was conducted in accordance with ASTM D1435-85 for 15 weeks in outdoor exposure weather resistance test to compare the change of impact strength and tensile strength with the existing ABS specimen and HIPS specimen. The ABS specimens to be compared were HF 380 grade (U.S. crude oil) and HIPS was made of solar H724 grade. The results are shown in FIGS. 1 and 2.

According to the present invention, it is possible to obtain a polystyrene-based resin composition which has excellent rigidity-impact resistance property balance, has characteristics such as weather resistance, chemical resistance, glossiness, and the like, and is easily adjusted. In addition, it is possible to impart the necessary properties by introducing a variety of additives while minimizing the deterioration of the physical properties to the base composition, in particular, when a variety of flame retardants are introduced, a flame retardant resin composition having excellent balance of excellent flame retardancy and resin basic properties Can be obtained. Therefore, the polystyrene-based resin composition of the present invention can be applied to fields in which existing polystyrene-based resins cannot be used.

Claims (13)

(A) 45 to 95% by weight of a homo or copolymer of styrene and styrene derivatives or rubber modified resins thereof; (B) 4 to 40% by weight of the modified polyolefin copolymer alone or in admixture with other olefin polymers; (C) A polystyrene-based resin composition comprising at least 1 to 15% by weight of a block copolymer of polystyrene and polyolefin in which one or two or more polystyrene blocks are divided by one or two polyolefin blocks. The method of claim 1, wherein the flame retardant, lubricant, heat improver, plasticizer, light stabilizer, antioxidant, mold release agent, antistatic agent, conductive additive, impact modifier, colorant, glass fiber, foaming agent, organic or inorganic filler A composition further comprising at least one additive selected. The flame retardant, lubricant, heat improver, plasticizer, light stabilizer, antioxidant, mold release agent, antistatic agent, conductive additive, impact modifier, colorant, glass fiber, foaming agent in place of the component (C). , At least one additive selected from the group consisting of organic or inorganic fillers. The compound according to any one of claims 1 to 3, wherein the modified polyolefin copolymer is a compound of formula 1 having an average molecular weight (M _w ) of 40,000 to 300,000 produced by polymerization with a metallocene-based single-part catalyst. Composition. Formula 1

[Wherein, n and m are integers from 1 to 500, X is hydrogen or an aromatic or aliphatic hydrocarbon of C1 to C950 or a copolymer thereof, Y is (CH ₂ ) wCH ₃ and W is an integer of 0 to 1000.] 5. The composition according to claim 4, wherein the modified polyolefin copolymer is a copolymer of ethylene and other alkenes produced by a metallocene-based single-part catalyst, and the content of an alkene compound is 5 to 50% by weight. The method according to any one of claims 1 to 3, wherein the other olefin copolymer is made of polyethylene, polypropylene, ethyl-vinyl copolymer, polyethylene-propylene and polyethylene-propylene-diene copolymer, and acrylic copolymer. Composition selected from the group. The composition of claim 1 or 2, wherein the block copolymer has a structure of S ₁ -O _1- (S ₂ ) _n or S ₁ -O ₁ -O _2- (S ₂ ) _m . [Wherein, S is a polystyrene block, O is a polyolefin block, n is 0 to 1 and m is an integer of 0 or more.] 8. The composition according to claim 7, wherein the styrene content in the block copolymer is 13 to 70% by weight. The method according to claim 1 or 2, wherein the block copolymer has a structure of S _m- (E _n -P _w ) _y -S _x or S _m- (E _n -B _w ) _y -S _x Composition. [Wherein, S is a polystyrene block, EP is a polyethylene, a polypropylene block, EB is a polyethylene, a polybutylene block, m ranges from 30 to 350, n and w ranges from 200 to 900, x ranges from 0 to 350, y is an integer from 1 to 100.] The composition according to claim 9, wherein the styrene content in the block copolymer is 13 to 70% by weight. A method for producing a polystyrene-based blend, wherein each of the composition components according to claim 1 or 2 is kneaded and extruded by a conventional kneading extrusion device. A process for producing a polystyrene-based polymerization reactant, wherein each of the composition components according to any one of claims 1 to 3 is subjected to a bulk or block-suspension polymerization reaction by a conventional HIPS polymerization unit. Molded article made from the composition according to any one of claims 1 to 10.

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