KR100796730B1 - Polypropylene resin composition having the improved resistance to blooming - Google Patents

Abstract

A polypropylene resin composition is provided to ensure good blooming resistance while exhibiting flame retardancy of the flammability class UL-94 V-2 even in a thickness of 1/32 inch. A polypropylene resin composition comprises (A) 75.0-95.0wt% of polypropylene resin, (B) 1.0-20.0wt% of a bromine-based flame retardant having good blooming resistance, (C) 1.0-5.0wt% of a flame retardant aid, and (D) 0.01-10.0wt% of a synthetic adsorbent. The polypropylene resin(A) has a melt index of 1-50 g/10minutes(230 °C) and is a propylene homopolymer and ethylene-propylene copolymer having crystallinity. The flame retardant aid(C) is antimony trioxide.

Description

Polypropylene resin composition having the improved resistance to blooming}

The present invention relates to a flame retardant polypropylene resin composition having excellent blooming resistance and high flame retardancy, and more particularly, to a flame retardant polypropylene resin composition prepared by blending an organic flame retardant and an antimony compound with polypropylene resin as a main component. It is about.

Polypropylene resin is widely used in the fields of injection molded products, films, blow molded products due to its excellent processing characteristics, chemical resistance, weather resistance, and high slidability, and is widely used in the fields of automobiles, building materials, electrical parts, etc. Various organic or inorganic flame retardants are added to give. In general, a flame retardant polypropylene resin is a method of using an organic or inorganic flame retardant and antimony trioxide in combination.

As a flame-retardant polypropylene resin composition containing such a flame retardant, a composition obtained by adding decabromodiphenyl ether, bis (pentabromophenyl) ethane, or the like as a bromine-based flame retardant (Japanese Patent Application Laid-Open No. 8-120126, Japanese Patent Application Laid-Open No. 7). -76640), a composition obtained by adding a tetrabromo bisphenol A-based or tetrabromo bisphenol S-based flame retardant (JP-A-8-302102), a hydrous inorganic compound such as magnesium hydroxide, aluminum hydroxide or hydrotalcite Obtained by adding to a polypropylene resin (Japanese Patent Laid-Open Nos. 53-92855, 54-29350, 54-77658, 56-26954, 57-87462 and 60-110738) ), Polyethylene with a melt index of 0.01 to 2.0, halogen compounds (e.g., decabromodiphenyl ether or dodecachloro-dodecahydromethanodibenzocyclooctene) and powder talc, kaolin, A composition obtained by adding one or more inorganic fillers selected from the group consisting of slate, silica and diatomite to the polypropylene resin (Japanese Patent Publication No. 55-30739) and ammonium phosphate (or amine phosphate), cyclic structure = C A composition obtained by adding a reaction product of a nitrogen compound having an = 0 (or = C = S or = NH) and an aldehyde or an oligomer (or polymer) of 1,3,5-triazine derivative to a polypropylene resin ( Japanese Patent Laid-Open Nos. 52-146452 and 59-147050).

As the resin used in the conventional electrical appliances, non-combustible resins, flame-retardant resins or self-plastic resins are used for the purpose of preventing ignition, combustion or fire generated from electrical troubles. For this reason, various proposals have been made regarding the flame retardant properties of olefin resins, especially polypropylenes, which are hydrocarbon-based materials, and are excellent in impact resistance, rigidity, appearance and formability. In particular, in the flame retardancy standards of electrical appliances, UL UL (UL94) of the United States requires a high degree of flame resistance according to the product or part, and export products to the United States is required to select a material that meets UL standards.

Appearance of the housing material by strengthening the flame retardant standard for small household appliances has been changed from HB class to V-2 or V-0 level by adopting flame retardant material since June 2004. For small housing according to the standardized (UL746C) High gloss, heat stability, and heat deformation resistance are important characteristics required for the material, and a technique of flame retardant while maintaining these characteristics is essential. In particular, the existing flame retardant material has a blooming problem due to the migration (migration) in a high temperature environment due to the flame retardant properties.

The present invention maintains the existing long-term heat stability by using a mixture of products having good blooming resistance and weakness in long-term heat stability and good long-term heat stability in a certain component ratio among the organic halogen flame retardant The purpose of the present invention is to obtain a flame retardant polypropylene resin composition which can exhibit blooming resistance by adding a synthetic adsorbent hydrotalcite, which is used as a halogen absorbent, in a flame retardant component that causes a blooming to an existing additive.

Flame retardant polypropylene resin composition of the present invention is (A) 75 to 95% by weight polypropylene resin having a melt flow index of 0.1 to 60g / 10 minutes, (B) bromine-based flame retardant having a bromine content of 30% by weight or more represented by the formula (I) To 10% by weight, (C) 1 to 10% by weight bromine flame retardant having a bromine content of 30% by weight or more represented by the following formula (2), (D) 1 to 5% by weight of flame retardant aids, and (E) a halogen absorbent having excellent blooming resistance By including 0.01 to 10% by weight, it is excellent in blooming resistance and long-term heat stability, and is a flame retardant polypropylene resin composition of UL94 V-2 grade.

(R ₁ , R ₂ is oxygen or an alkylene group having 1 to 6 carbon atoms; i, j represent an integer of 1 to 6).

(R ₃ is sulfur dioxide; R ₄ is an alkylene group having 1 to 6 carbon atoms; k, l represent an integer of 1 to 6.)

Halogen absorbent (E) included in the composition of the present invention is a hydrotalcite represented by the following formula (3).

Mg _{4 .3} Al ₂ (OH) _12.6 CO ₃ ㆍ 5H ₂ O

The polypropylene resin included in the composition of the present invention is a propylene olefin block copolymer or a propylene homopolymer containing 50% by weight or more of propylene polymerized units.

Specifically, the polypropylene resin is selected from the group consisting of crystalline polypropylene homopolymer, or ethylene, 1-butene, 1-pentene, 1-hexene, 4-methylpentene, 1-heptin, 1-octene and 1-decene It is a crystalline copolymer of at least one compound selected or a mixture of two or more compounds selected from the group with a polypropylene as a main component. The polypropylene resin may have a melt flow index of 0.1 to 60 g / 10 minutes, preferably 0.3 to 40 g / 10 minutes.

Regarding the stereoregularity of the polypropylene resin, any form for achieving the object of the present invention may be used as long as it is crystalline polypropylene without particular limitation. Specifically, the isotactic pentad fraction measured by 13 C-NMR (nuclear magnetic resonance spectrum) is 0.80-0.99, preferably 0.85-0.99, particularly preferably 0.90-0.99 crystalline polypropylene resin.

The composition of this invention is 65 to 99 weight% of (A) polypropylene resin, and 75 to 95 weight% is preferable. When the resin compounding amount exceeds 99% by weight, flame retardancy is not good, and when the resin compounding amount is less than 65% by weight, heat resistance and molding processability are not good, which is not preferable.

Bromine-based flame retardants (B) and (C) contained in the composition of the present invention are generally commercially available products. If the content of the flame retardant is less than 1% by weight, respectively, the flame retardancy is not satisfactory. If the content of the flame retardant is 10% by weight or more, the heat resistance and the molding processability are not good. In particular, the brominated flame retardant (B), (C) is preferably used in a ratio of 1: 9 to 9: 1 in terms of flame retardancy and physical properties of the composition. If the composition ratio of (B) is 10% or less, there may be a problem of the expression of flame retardancy, and if the composition of (C) is 10% or less, the blooming resistance may be deteriorated.

As the flame retardant aid (D) included in the composition of the present invention, commercially available antimony trioxide is generally used. Although antimony trioxide is powder form, it is preferable that the average particle diameter is 0.2-5.0 micrometers. The compounding amount is 1 to 5% by weight based on the total composition. Antimony trioxide and brominated flame retardants (B) (C) show synergistic effects in flame retardancy. The amount of antimony trioxide blended is preferably used in an amount of 1/6 to 2/1 of the bromine flame retardant in terms of flame retardant effect.

As a halogen absorber (E) contained in the composition of this invention, a commercial item generally used is used as a synthetic adsorbent. Generally, synthetic adsorbents are white, odorless fine powders and commonly used as antacids to effectively inactivate and deactivate Zieggler Natta catalysts, Friedel Kraft catalysts or acid catalysts. Calcium Sterate was used a lot, but it reacts with acid to form CaCl ₂ and stearic acid, and CaCl ₂ has high hygroscopicity and has a side effect of dissolving in water. In addition, stearic acid has a blooming problem when left at a high temperature later from the corrosion of the molded article and the molded surface. Halogen absorbent (E) represented by the formula (3) included in the composition of the present invention is to improve the blooming problem as well as effective antacid.

The composition of this invention can use various additives in order to further improve mechanical characteristics, such as rigidity, and heat resistance. For example, it may include a plate-like activity, fillers such as silica, clay, kaolin, glass fiber, calcium carbonate, fillers such as mica, and these inorganic fillers may be used alone or in combination of two or more.

The composition of the present invention is prepared by mixing and kneading the above components, and is used as a flame retardant polypropylene resin molding material. A polypropylene resin molded article can be obtained by molding it by a conventional molding method such as injection molding or extrusion molding.

The polypropylene resin molded article of the present invention is made of a resin composition exhibiting UL94 V-2 flame retardancy that ensures long-term heat resistance and blooming resistance in the state of blending two bromine flame retardants and antimony trioxide as a flame retardant synergist. It can be preferably used as electric and electronic parts, automobiles, building materials.

The flame retardant polypropylene resin composition of the present invention can be produced by the following method. That is, the weighted (A) polypropylene resin, (B) bromine flame retardant represented by the formula (C) (C) bromine flame retardant represented by the formula (2), (D) antimony trioxide, (E) synthetic adsorbent and other additives Is charged into a stirring-mixer [e.g., a Hensel mixer (tradename), a super mixer, or a tumbler mixer), and the mixture is stirred-mixed for 1 to 10 minutes and melted using a rolling mill or an extruder at a temperature of 180 to 270 ° C. And kneading to obtain pellets.

The invention may be understood in more detail by the following examples, which are intended for purposes of illustration of the invention and are not intended to limit the scope of protection defined by the appended specific claims.

Example  1 to 3

In order to prepare the flame retardant polypropylene resin composition of the present invention, the polypropylene resin, flame retardant, flame retardant aid, synthetic adsorbent and other additives were charged to a stirring and mixing apparatus at a composition ratio shown in Table 1 below, and stirred and mixed for 5 minutes. The pellets were then melted and kneaded using an extruder at a temperature of 220 ° C.

The physical properties of the composition were evaluated by the following method. The results are shown in Table 1 below.

How to measure

1) flammability

Based on UL subject 94 (Combustibility test of plastic materials for machine parts) vertical burning test (V-2) of Underwrites Laboratories Incorporation. The thickness of the specimen used was 0.8 mm.

2) Blooming resistance

The composition used Samsung Kleukner FCM-110 (molding force = 110 tons) injection machine, the injection temperature is 30/200/200/200/200 ℃, nozzle temperature 60 ℃, injection pressure 60 ~ Injection molding at 100 bar to prepare a test specimen for the appearance (thickness 2.0mm) and the prepared sample was left for 72 hours in a 70'C oven to measure the appearance of the specimen.

Comparative example  1 and 2

The polypropylene resin composition was prepared and pelletized according to the composition ratios shown in Table 1 below. Evaluation of the physical properties of the composition in the same manner as in the above Example is shown in Table 1 below.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 1) polypropylene resin 95 95 95 95 96 2) Flame retardant 1 (DBP-TBA) 1.5 3 3 2) Flame Retardant 2 (DBP-TBS) 3 1.5 3 3) Flame retardant One One One One One 4) Synthetic Adsorbent (DHT-4A) One One One 5) COLOR M / B (Black) 3 3 3 3 3 Measurement result Flame retardant (UL94 V-2) V-2 V-2 V-2 V-2 V-2 Blooming resistance ◎ ○ ○ X X

(◎: No blooming is observed at all, ○: Blooming degree is good, X: Poor appearance)

1) Polypropylene: High Crystalline Polypropylene, Samsung Total, Melt Index (MI): 1 ~ 50G / 10min

2) Flame Retardant:

Flame retardant-1: (DBP-TBA, Tetrabromo-bisphenol-A-bis (2,3-dibromopropyl ether), Dead Sea

Flame retardant-2: (DBP-TBS, Bis (3,5-dibromo-4 (2,3-dibromopropxy) phenyl) sulfone), Suzuhiro

3) Flame retardant aid: antimony trioxide, Sinochem plastics company

4) Synthetic adsorbent: DHT-4A, Mg4.3Al2 (OH) 12.6CO3- 5H2O

5) Color M / B: M22K, (PP 22% Base), Woosung Chemical

Table 1 shows a formulation of DBP-TBS, which is a brominated flame retardant having excellent blooming resistance, and a hydrotalcite as a synthetic adsorbent, from the above UL-94 V-2. It showed the best blooming resistance while maintaining flame resistance. In addition, in the case of Example 2 in which the flame retardant 2 (DBP-TBS) and the flame retardant 1 (DBP-TBA) were blended in the same ratio, the synthetic adsorbent was simultaneously formulated, excellent blooming resistance was obtained. Even if a synthetic adsorbent was prescribed, Comparative Example 1, which applied flame retardant 1 (DBP-TBA), which had poor blooming resistance, was considered to have a severe blooming degree. It was confirmed that the selection of this excellent flame retardant is required.

The flame retardant polypropylene resin composition of the present invention has excellent flame resistance while exhibiting flame retardancy of UL-94 V-2 even at a thin thickness of 1/32 inch (inch). It is preferred for use in the manufacture of cosmetics requiring color.

Claims (8)

(A) 75.0-95.0 weight% of polypropylene resin, (B) 1.0-20.0 weight% of bromine type flame retardant excellent in blooming resistance (C) 1.0-5.0 weight% of flame retardant adjuvant, and (D) 0.01-10.0 weight% of synthetic adsorbent Polypropylene resin composition comprising a. The polypropylene resin composition according to claim 1, wherein the polypropylene resin (A) has a melt index of 1 to 50 g / 10 min (230 ° C.) and is a propylene homopolymer and an ethylene-propylene copolymer having crystallinity. . The polypropylene resin composition according to claim 1, wherein the flame retardant (B) is a mixture of the compounds represented by the following general formulas (1) and (2). [Formula 1]

(R ₁ , R ₂ is oxygen or an alkylene group having 1 to 6 carbon atoms; i, j represent an integer of 1 to 6). [Formula 2]

(R ₃ is sulfur dioxide; R ₄ is an alkylene group having 1 to 6 carbon atoms; k, l represent an integer of 1 to 6.) The polypropylene resin composition according to claim 3, wherein the compounding amount of the compound represented by Formula 1 and Formula 2 is 1: 9 to 9: 1. The polypropylene resin composition according to claim 1, wherein the flame retardant aid (C) is antimony trioxide. The polypropylene resin composition according to claim 1, wherein the flame retardant aid (C) is used in an amount of 1/6 to 2/1 of the flame retardant (B). The polypropylene resin composition according to claim 1, wherein the synthetic adsorbent (D) is hydrotalcite represented by the following Chemical Formula 3. [Formula 3] Mg _{4 .3} Al ₂ (OH) _12.6 CO ₃ ㆍ 5H ₂ O The polypropylene resin molded article according to any one of claims 1 to 7, which is produced using a polypropylene resin composition.