KR20060124346A - Flame retardant polypropylene resin composition with good weatherability - Google Patents

Abstract

Provided is a flame retardant polypropylene resin composition which is excellent in weather resistance and is applied to an air-conditioning plant housing or an outdoor speaker housing. The composition comprises 30.0-96.0 wt% of a polypropylene resin; 1.0-50.0 wt% of silica or wollastonite as an inorganic filler; 1.0-40.0 wt% of a bromine-based flame retardant; 1.0-15.0 wt% of a flame retardant aid; and 0.01-10.0 wt% of a UV stabilizer. Preferably the polypropylene resin has a melt index (MI) of 1-50 g/10 min (ASTM D1238, 230 deg.C); the silica has an average diameter of 1-15 micrometers; the wollastonite has a strand shape having an average diameter of 5-15 micrometers and a length of 1-16 mm; the flame retardant is tris(tribromopentyl)phosphate or 1,2-bis(pentabromophenoxy)ethane; and the flame retardant aid is antimony trioxide.

Description

Flame-retardant polypropylene resin composition excellent in weatherability {FLAME RETARDANT POLYPROPYLENE RESIN COMPOSITION WITH GOOD WEATHERABILITY}

The present invention relates to a flame retardant polypropylene resin composition having excellent weather resistance, and more particularly to a flame retardant polypropylene resin composition having excellent weather resistance including a polypropylene resin, an inorganic filler, a flame retardant, a flame retardant aid and a UV stabilizer.

Although polypropylene resin is a general-purpose resin, it has excellent mechanical properties and formability, and thus has a wide range of industrial applications such as automobile interior parts, home appliances parts, and industrial materials. In particular, the air conditioner outdoor unit or outdoor speaker housing, which has recently been applied to steel, has been in full swing as a polypropylene injection molded product that is easy to form and assemble.

However, due to its chemical structure, polypropylene has less self-extinguishing ability than existing steels, resulting in safety problems, and flame retardancy has been promoted to secure flame retardancy. Increasing use has slowed while revealing problems.

In order to improve these problems, various methods for improving the light resistance and weather resistance, which are disadvantages of the flame retardant polypropylene resin, have been proposed by adding a light resistant agent and a post stabilizer to the flame retardant polypropylene resin.

In this regard, Japanese Patent Laid-Open Publication No. 5-214174, Japanese Patent Laid-Open Publication No. 8-49282, and Japanese Patent Laid-Open Publication No. 6-136188, etc. have been commercialized to improve the weather resistance by adding a flame retardant and UV stabilizer to polypropylene. When fillers such as talc are added, flame retardancy is difficult to secure, quality control is difficult, and the prescription amount of weather stabilizer is very high.

The present invention is to solve the problems of the prior art as described above, inorganic fillers that can prevent the reduction of flame retardancy which was a problem when adding talc to the conventional flame retardant polypropylene, flame retardant excellent light resistance and UV stabilizer excellent in light resistance improvement effect It is to provide a flame-retardant polypropylene resin composition excellent in weatherability that can be obtained excellent weatherability and flame retardancy by minimizing the physical property degradation by oxidation even after long-term use by the addition.

The flame-retardant polypropylene resin composition excellent in weatherability according to the present invention is 30.0 to 96.0% by weight of polypropylene resin, 1.0 to 50.0% by weight of silica or wollastonite as inorganic filler, 1.0 to 40.0% by weight of brominated flame retardant, 1.0 to 15.0% of flame retardant % And 0.01 to 10.0% by weight UV stabilizer is characterized in that it comprises.

The polypropylene resin used in the present invention is preferably a propylene homopolymer and an ethylene-propylene copolymer having a melt index (MI) of 1 to 50 g / 10 minutes (ASTM D1238, 230 ° C). When the melt index is less than 1g / 10 minutes, the moldability of the parts may not be good, which may result in molding defects. On the other hand, when the melt index exceeds 50g / 10 minutes, the impact strength is sharply lowered, so that the product is harsh for outdoor use. Not suitable for conditions of use

As the inorganic filler used in the present invention, silica or wollastonite is preferable.

In the case of the silica, it is preferable to use an average particle diameter of 1 ~ 15㎛ in consideration of appearance and workability. If the average particle diameter is less than 1㎛ to fly like fine powder in the mixing process may be a problem of proper content control and dispersibility, if it exceeds 15㎛ the appearance of the molded article is poor. In addition, the content of silica is preferably 1.0 to 50.0% by weight, when the silica content is less than 1.0% by weight, the effects of improving rigidity and shrinkage are inadequate, and when exceeding 50.0% by weight, extrusion workability is inferior. The appearance is not good.

In the case of wollastonite, it is preferable to use a chopped strand having an average particle diameter of 5 to 15 µm and a length of 1 to 16 mm in consideration of the kneading operation. In addition, the content of wollastonite is preferably 1.0 to 50.0% by weight, but when the content of wollastonite is less than 1.0% by weight, the effect of stiffness is inadequate, and when it exceeds 50.0% by weight, extrusion workability is inferior and the appearance is poor. Not good

The flame retardant used in the present invention is used for imparting flame retardancy of the polypropylene resin composition, and specifically, a bromine (Br) -based flame retardant is preferable. As the Br-based flame retardant, tris (tribromopentyl) phosphate or 1,2-bis-pentabromophenoxy ethane is preferably used. When the content of the flame retardant is less than 1.0% by weight, the flame retardancy cannot be sufficiently secured. When the content of the flame retardant is less than 1.0% by weight, the effect of improving the flame retardancy can not be expected. There is a risk of deterioration of workability.

As the flame retardant aid used in the present invention, antimony trioxide is used, and the content is preferably 1.0 to 15.0% by weight. When the content of the flame retardant aid is less than 1.0% by weight, the synergistic effect with the Br-based flame retardant may not be sufficiently expected, and when the content of the flame retardant exceeds 15.0% by weight, no further flame retardancy improvement effect may be expected.

UV stabilizers used in the present invention are used to improve the weather resistance of polypropylene, and are represented by, for example, 2- (2'-hydroxy-3'-tertiary-butyl-5-methylphenyl) -5-chloro-benzotriazole. Benzotriazole-based, bis- (2,2,6,6-tetramethyl-4-piperidinyl) sebacate; benzoic, typified by 2-hydroxy-4-n-octyloxybenzophenol Phenone, poly-{[6- (1,1,3,3-tetramethylbutyl-imino) -1,3,5-triazino-2,2-diyl] [2- (2,2,6 , 6-tetramethylpiperidinyl) -amino] -hexamethylene- [4- (2,2,6,6-tetra-methylpiperidinyl) imino]}, poly {(6-morpholino-s- Strazine-2,4-diyl) [(2,2,6,6-tetramethyl-4-piperidinyl) imino] -hexane [(2,2,6,6-tetramethyl-4-piperadi I) imino]} is preferably used by mixing one or two or more selected from. The amount of UV stabilizer is preferably 0.01 to 10.0% by weight. If the content of the UV stabilizer is less than 0.01% by weight, the anti-oxidation effect of the polymer is insufficient, thereby improving the weather resistance, and when it exceeds 10.0% by weight, the cost increases. Due to this lack of commerciality, it can lead to property degradation.

The flame retardant polypropylene resin composition having excellent weather resistance of the present invention includes a variety of conventional additives such as reinforcing materials, fillers, heat stabilizers, weather stabilizers, antistatic agents, lubricants, slip agents, pigments, dyes, and the like within the range of the characteristics of the present invention. Specific examples thereof include carbon fiber, calcium carbonate, clay, alumina, carbon black, magnesium hydroxide, zeolite, barium sulfate, and the like.

As a method for producing the polypropylene resin composition of the present invention, kneading using a twin screw extruder is preferable, and mixing at a polypropylene melting point or more is also possible using processing conditions for producing a polypropylene resin composition which is commonly known.

The present invention can be understood in more detail by the following examples and comparative examples, the following examples are only examples for illustrating the present invention, and are not intended to limit the protection scope of the present invention.

Examples and Comparative Examples

In the ingredients and blending ratios of Table 1, polypropylene resin, silica or wollastonite, flame retardant, flame retardant aid and UV stabilizer were dry blended with a Henschel mixer, and then all were added to the hopper of the JSW TEX44 Alpha (ALPHA) twin-screw kneading extruder at once. After melting and kneading together in the extruder to manufacture the resin composition, and then injected into Samsung Klucner FCM-110 (molding force = 110 tons) to produce a specimen specified in the ASTM standard, tensile strength, elongation, flexural modulus, impact strength, Flame retardancy and discoloration (appearance) were measured.

In addition, for evaluation of light resistance, annealing for up to 4000 hours at Weather-O-Meter was performed to measure changes in physical properties such as tensile strength, Izod impact strength and discoloration. The results are shown in Table 1.

Test conditions for each test property are as follows.

1) Tensile strength and elongation

It was measured at room temperature by the method of ASTM D638.

2) Flexural modulus

It was measured at room temperature by the method of ASTM D790.

3) impact strength

It was measured at room temperature by the method of ASTM D256.

4) Flame retardant

It was measured by the UL94 vertical combustion test method.

5) degree of discoloration

The discoloration was observed visually.

The description of each component used in Examples 1-2 of Table 1 and Comparative Examples 1-3 is as follows.

1) Polypropylene: Highly crystalline polypropylene, Samsung Total,

                 Melt Index (MI): 30g / 10min

2) Inorganic fillers:

-Silica: High purity natural crystalline silica, KOSEM, average particle size 4㎛

Wollastonite: NYCO Minerals, average particle diameter 10㎛

-Talc (Talc, Magnesium silicate hydrate): KOCH, average particle diameter 10㎛,

                                           Specific gravity 2.9 g / cm 3

3) Flame Retardant:

Flame retardant-1: Tris (tribromopentyl) phosphate, Deadsea

-Flame retardant-2: decabromodiphenyl oxide, ALBERMALE

4) Flame retardant aid: antimony trioxide, Suzuhiro

5) UV stabilizer: UV agent-1: UV agent-2 = 1: 1

UV agent-1: 2- (2'-hydroxy-3'-tertiary-butyl-5-methylphenyl) -5-chloro-benzotri

           Azole, CIBA GEIGY

UV agent-2: bis- (2,2,6,6-tetramethyl-4-piperidinyl) sebacate

As can be seen from the results of Table 1, Comparative Example 1 to which talc was applied was difficult to secure flame retardancy, and in Examples 1 to 2 where TPP flame retardants having excellent light resistance to silica or wollastonite were used, Comparative Examples 2 to 2 using DBDPO flame retardants. It showed less discoloration after WOM long-term test compared to 3, and showed excellent weather resistance that maintained physical properties such as tensile strength and Izod impact strength.

The flame-retardant polypropylene resin composition excellent in weatherability prepared according to the present invention is suitable for use in home appliances and industrial parts that require high weatherability and flame retardancy as it is used outdoors such as an air conditioner outdoor unit housing and an outdoor speaker housing.

Claims (7)

30.0 to 96.0% by weight of polypropylene resin, 1.0 to 50.0% by weight of silica or wollastonite as inorganic filler, 1.0 to 40.0% by weight of brominated flame retardant, 1.0 to 15.0% by weight of flame retardant, and 0.01 to 10.0% by weight of UV stabilizer Flame-retardant polypropylene resin composition excellent in weatherability. The flame-retardant polypropylene resin composition having excellent weather resistance according to claim 1, wherein the polypropylene resin has a melt index (MI) of 1 to 50 g / 10 minutes (ASTM D1238, 230 ° C). The flame retardant polypropylene resin composition having excellent weather resistance according to claim 1, wherein the silica has an average particle diameter of 1 to 15 µm. The flame retardant polypropylene resin composition having excellent weather resistance according to claim 1, wherein the wollastonite is in the form of a strand having an average particle diameter of 5 to 15 µm and a length of 1 to 16 mm. The flame retardant polypropylene resin composition having excellent weather resistance according to claim 1, wherein the flame retardant is tris (tribromopentyl) phosphate or 1,2-bis-pentabromophenoxyethane. The flame retardant polypropylene resin composition excellent in weatherability according to claim 1, wherein the flame retardant aid is antimony trioxide. The flame retardant polypropylene resin composition having excellent weather resistance according to claim 1, wherein the UV stabilizer is used by mixing one or two or more selected from benzotriazole-based, sebacate-based and benzophenone-based compounds.