KR19980066699A - Polystyrene Blend Compositions and Flame Retardant Compositions thereof - Google Patents

Abstract

The present invention (A) homo- or copolymer of styrene and styrene derivative, or rubber-modified resin 45 to 95% by weight thereof; (B) 4 to 40% by weight of the modified polyolefm pin copolymer resin prepared in the presence of a metallocene catalyst; (C) 1 to 15% by weight of a block copolymer of polystyrene and polyolefin in a state in which two styrene blocks are divided by butadiene or polyolefin blocks, optionally (D) flame retardant, lubricant, heat improver, plasticizer The present invention relates to a polystyrene blend composition comprising at least one additive selected from the group consisting of a light stabilizer, a mold release agent, an antistatic agent, an impact modifier, a colorant (dye or pigment), a glass fiber, and a blowing agent.

The polystyrene-based blend composition according to the present invention has high impact strength and tensile strength, excellent weather resistance and gloss, and is excellent in its application to non-flammable and flame-retardant injection molded articles, and can be widely used in extruding articles according to the appropriate blending of additives. Do.

Description

Polystyrene Blend Compositions and Flame Retardant Compositions thereof

The present invention relates to a highly functionalized polystyrene-based blend composition and a molded article thereof, and more particularly, to a homo or copolymer of styrene and a styrene derivative or a blend composition of a rubber-modified resin thereof and a modified polyolefin. And a blend itself composition having excellent balance of toughness and excellent weatherability, high gloss characteristics, and a flame retardant composition having excellent weatherability and flame retardant properties with an extremely small property deterioration. It relates to each molded article.

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) that compensates for its fragile disadvantages by introducing elastomers such as polybutadiene, styrene-butadiene copolymer rubber, and the like. Styrene resin by copolymerization and blend of SMA, SAN, ABS, ABS / PC, AES, AAS etc. which were devised to have other characteristics are 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 due to the added elastomer and impurities, structural defects due to UV, deterioration of physical properties, yellowing phenomenon, and the like appear. Therefore, there are many limitations on its application range.

In order to remedy these shortcomings, the structure of the main chain and the added elastomer is changed, various additives such as UV stabilizers, antioxidants and whiteness improvers are added, or copolymerized resins with second and third monomers are formed. Techniques for forming blend compositions with, polyolefins, enpra resins and the like have been developed. In order to improve the glossiness, an attempt was made to minimize the dispersed particle size by adjusting the type and process parameters of the added elastomer. However, in most cases, all of the desired physical properties were not satisfactorily improved, and when the improvement in physical properties was satisfied to some extent, there was a difficulty in commercialization and commercialization due to the expensive manufacturing cost.

For example, in the case of polystyrene prepared by polymerizing styrene monomer in the presence of ethylene-propylene-diene terpolymer (EPDM) rubber to improve weather resistance and toughness, an effective physical property improvement can be expected due to the small graft bonding force between EPDM rubber and styrene. In addition, the dispersed particles were enlarged (10 to 20 µm), resulting in 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.) However, in order to show the required impact strength, a large amount of expensive styrene / butadiene copolymer had to be added, and there were problems in economics and manufacturing process, and other physical properties such as tensile strength decreased in inverse proportion to increase in impact strength. There was a downside.

Meanwhile, 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.). The main purpose of this method was to improve the weather resistance and to improve the overall physical properties of the blend composition.However, the physical properties such as stiffness were inferior to the improvement of impact resistance. It was not easy, and the introduction of other special additives did not have physical stability in various application aspects. At present, some of these compositions have been commercialized, and 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. When developed as a molded article (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). 11.5 to 26.9 N / mm ² ) is very large and the increase in impact strength is insignificant, and it does not give special characteristics such as gloss and flame retardancy.

Looking at the development of such a series of polystyrene composition, in the general-purpose polystyrene (GPPS), which is transparent, high gloss, and has excellent rigidity but very poor impact resistance, transparency is excluded by addition of elastomers such as various rubbers. Changes to impact-resistant polystyrene (HIPS), which improves impact and elongation characteristics, but is poor in weatherability and inferior in stiffness and gloss, can be primarily examined. Next, we will look at a number of improvement methods to overcome the disadvantages of gloss, transparency, stiffness, heat resistance and weather resistance, which are disadvantages of such impact-resistant polystyrene. Methods such as keeping the content low, introducing copolymer monomers such as MMA and BA for improving transparency, introducing other special elastomers for improving rigidity and weather resistance, or blending with polyolefin derivatives in the presence of various compatibilizers The method of constructing a composition, etc. are mentioned. However, in the case where the respective methods are applied, a reliable commercially viable method that can effectively improve the disadvantages of polystyrene and thus the improvement of other physical properties that are lowered thus far has not been developed to a satisfactory level.

From this point of view, while satisfying both the rigidity and impact resistance of general-purpose polystyrene and impact resistance of polystyrene at the same time, it is easy to control other special physical properties such as gloss, weather resistance, chemical resistance, flame retardancy, etc. 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.

In accordance with such a requirement, the present inventors have examined various combinations of matrix phases and disperse phases, compatibilizers, etc. in order to obtain a highly functionalized polystyrene resin composition, and thus can be prepared in the presence of a metallocene catalyst on a suitable polystyrene resin matrix. The fact that a polystyrene-based blend composition having an effective dispersion phase and stability can be produced at low cost by using a modified polyolefin-based copolymer resin as a dispersed phase and adding a compatibilizer composed of an appropriate amount of styrene-olefin block copolymer Discovered to complete the present invention. In such a polystyrene blend composition according to the present invention, additives for imparting various properties can be added, and in this case, the decrease in physical properties is very small even in the prescription, and particularly in the flame retardant composition, it was confirmed that the physical properties of the conventional ABS resin are higher. .

Accordingly, an 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 has excellent characteristics of high weather resistance, high gloss and control It is possible to provide a highly functionalized polystyrene-based blend composition and a method for producing the same, which are excellent in workability and handling properties and which can impart other properties such as flame retardancy without deteriorating physical properties.

In addition, it is an object of the present invention to provide a polystyrene-based blend composition and a method of manufacturing the same having excellent properties as described above, as well as flame retardancy.

Furthermore, an object of the present invention is to manufacture a variety of molded articles at low cost by using the polystyrene-based blend composition according to the present invention in many fields where conventional general-purpose polystyrene, impact-resistant polystyrene, polystyrene blends could not be used.

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 a homo or copolymer of styrene and styrene derivatives or rubber modified resins thereof; (B) 4 to 40% by weight of the modified polyolefm pin copolymer resin prepared in the presence of a metallocene catalyst; (C) Provided is a polystyrene blend composition comprising 1 to 15% by weight of a block copolymer of polystyrene and polyolefin in a state where two styrene blocks are divided by butadiene or polyolefin blocks.

According to the second embodiment of the present invention, in addition to the components (A), (B) and (C), (D) flame retardant, lubricant, heat improver, plasticizer, light stabilizer, mold release agent, antistatic agent, impact Provided is a polystyrene-based blend composition further comprising one or more additives selected from the group consisting of reinforcing agents, colorants (dyes or pigments), glass fibers, foaming agents.

According to the third embodiment of the present invention, various molded products such as injection molded articles and extruded articles manufactured using the polystyrene blend composition are provided.

Polystyrenes used in the blend compositions of the present invention include homo or copolymers of styrene and styrene derivatives, and rubber modified resins thereof, with molecular weights ranging from 100,000 to 350,000. Its content is preferably 45 to 95% by weight, more preferably 60 to 85% by weight.

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

[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 ) _w CH ₃ ,

W is an integer of 0 to 1000.]

4 to 40% by weight, preferably 10 to 30% by weight, the average molecular weight (M _w ) is 40,000 to 300,000. In particular, as a metallocene catalyst copolymer of ethylene and other alkene compounds, it is especially preferable that the alkene compound content rate is 5 to 50 weight%.

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

[Formula 2]

S ₁ -O ₁ -S ₂

[Formula 3]

S ₁ -O ₁ -O ₂ -S ₂

The polystyrene block has a proportion of 15 to 50% by weight of the total polymer block and has a molecular weight of 5,000 to 75,000.

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

[Formula 3a]

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

[Formula 3b]

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

Wherein S is a polystyrene block, EP is a polyethylene, a polypropylene block, EB is a polyethylene, a polybutadiene block. m ranges from 30 to 350, n and w ranges from 200 to 900, and x ranges from 0 to 350. y is an integer from 1 to 100. In each case, the content of styrene blocks 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.

To the polystyrene blend composition according to the present invention, various additives can be added without accompanying deterioration of physical properties such as impact strength and tensile strength. Examples of the additives include flame retardants, lubricants, heat improvers, plasticizers, light stabilizers, mold release agents, antistatic agents, impact modifiers, colorants (dyes or pigments), glass fibers, foaming agents, and the like.

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 blend may be 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 a halogen flame retardant and a non-halogen flame retardant, as well as flame retardant aids 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 is manufactured by kneading extrusion by kneading extrusion means such as an extruder, a Blabender Plasticorder, a Banbury Mixer, a Mixing Roll, a Kneader, or the like. 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.

The polystyrene-based blend composition according to the present invention can be produced in non-flammable and flame-retardant injection molded article according to a conventional molding method, it is also possible to prepare an extrusion molded article 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 Solarene polystyrene grade (Eastern Chemical), component (B) is a polyolefin copolymer grade modified by a metallocene-based single-part catalyst, and component (C) is Styrene-poly (ethylene-propylene) -styrene block copolymers and styrene-poly (ethylene-butadiene) -styrene block copolymers were used in the amounts shown in Table 1 below, respectively.

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 blend water after drying at room temperature, the test piece was injected under the conditions of the injection molding machine temperature 210 ℃, mold temperature 50 ℃, molding cycle 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 according to ASTM D523, a specimen having a diameter of 56.0 mm and a thickness of 1.6 mm was prepared, and a gloss meter was used at an incident angle 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.

TABLE 1a

TABLE 1b

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 below. As flame retardants of component (D), halogen-based flame retardants, non-halogen flame retardants, and 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.

TABLE 2

Comparative Example 1

As shown in Table 3, pelletized solar polystyrene grade (Eastern Chemistry) as component (A), high density polyethylene (HDPE) and linear low density polyethylene (LLDPE) as component (B), of polystyrene and olefin as component (C) Using a crosslinked copolymer, a blend was prepared by the same method 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.

TABLE 3

Weather resistance test

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 the outdoor exposure weather resistance test to compare the change of impact strength and tensile strength with the existing ABS specimen and HIPS specimen. ABS specimens to be used were HF 380 grade (un-emulsification) and HIPS was used as solar H72 grade (Eastern Chemistry). The results are shown in FIGS. 1 and 2.

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

Claims (7)

(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 polyene pin copolymer resin; (C) A polystyrene blend composition comprising 1 to 15% by weight of a block copolymer of polystyrene and polyolefin in a state in which two styrene blocks are divided by butadiene or polyolefin blocks. The method of claim 1, wherein at least one additive selected from the group consisting of flame retardants, lubricants, heat improvers, plasticizers, light stabilizers, mold release agents, antistatic agents, impact modifiers, colorants (dyes or pigments), glass fibers, and foaming agents is used. A composition comprising more. The composition of claim 1 or 2, wherein the modified polyolefin copolymer is an average molecular weight (M _w ) produced by polymerization by a metallocene-based single-part catalyst, wherein the compound of Formula 1 is 40,000 to 300,000. 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 ) _w CH ₃ and W is an integer from 0 to 1000.] 4. The composition according to claim 3, 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 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 polybutadiene 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 5, wherein the styrene content is 13 to 70% by weight in the block copolymer. Molded article made from the composition according to any one of claims 1 to 6.