JPH10251466A - Flame-retardant polyolefin resin composition and its molded item - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a nonhalogen flame-retardant polyolefin resin compsn. which is excellent in flame retardancy and injection moldability and hardly emits an order during processing by compounding a polyolefin resin with an ethylene-vinyl acetate copolymer, Mg(OH)2 , red phosphorus, TiO2 , and a carbon black, each in a specified amt. SOLUTION: This compsn. contains 45-55 pts.wt. polyolefin resin (pref. PP having an MFR of 1-50g/10min at 230 deg.C under 2.16kg-load), 2-5 pts.wt. ethylene- vinyl acetate copolymer pref. having a vinyl acetate unit content of 10-30%, 30-40 pts.wt. Mg(OH)2 pref. having an average particle size of 0.1-20μm and a density of 2.00-2.50g/cm<3> , 4-6 pts.wt. red phosphorus which hardly emits an odor and pref. has an average particle size of 1-50μm and of which at least 92% has been specially coated, 1-5 pts.wt. TiO2 pref. having an average particle size of 0.1-0.3μm and a density of 4.1-4.5g/cm<3> , and 1.5-3 pts.wt. carbon black, the sum of the above ingredients being 100 pts.wt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyolefin-based flame-retardant resin composition and a molded product, and more particularly, to internal parts (connectors, substrate holders, etc.) requiring flame retardancy, such as home electric appliances and automobiles. The present invention relates to a polyolefin-based flame-retardant resin composition which is currently widely used as a flame-retardant polyolefin material, such as an exterior material which is not restricted by appearance and color, and a molded article using this composition.

[0002]

2. Description of the Related Art Conventionally, polyethylene and polypropylene are semi-crystalline and extremely flammable. Therefore, halogen-based flame retardants and Sb
It has been common practice to use ₂ O ₃ in combination to make it flame-retardant. However, it has been reported that these flame retardants may generate substances harmful to the human body such as dioxin and halogen when burned, and Sb ₂ O ₃ is becoming a problem as an environmental destructive substance. for that reason,
There is a demand for non-halogen, non-antimony conversion of flame retardants for polyolefins. Polyolefins (especially polyolefins for injection molded products) are difficult to flame retardant other than halogen-based flame retardants due to their properties. However, flame retarding technology by blending large amounts of metal hydrates such as magnesium hydroxide, or A flame-retardant technique by a synergistic effect of metal hydrate and carbon black is already known, and is used for electric wires and cables. However, when a large amount of a metal hydrate is blended with a polyolefin, problems such as poor appearance, poor physical properties, and cost are caused. To reduce the amount of metal hydrate, red phosphorus, carbon black, and the use of auxiliary agents such as metal oxides have been reported, but the flame retardant level is still lower than that of halogenated flame retardants. Low and hardly used in the field of injection molding. Also,
When red phosphorus is used in combination, the odor of phosphorus causes a problem in productivity during granulation and molding, and the molded product is not preferable as compared with a general polyolefin molded product.

[0003]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art and exhibits high flame retardancy while having the same physical properties as those obtained when a conventional halogen-based flame retardant is used.
An object of the present invention is to provide a non-halogen polyolefin-based flame-retardant resin composition which is suitable for injection molding, is effective for environmental protection, and has little odor during granulation and processing, and a molded article using the same.

[0004]

The inventors of the present invention have conducted intensive studies and have found that ethylene-vinyl acetate copolymer, metal hydrate, red phosphorus, carbon black and titanium oxide are mixed in a specific ratio with polyolefin. As a result, it has been found that the above object can be achieved, and the present invention has been completed. That is,
The present invention relates to (A) 45 to 55 parts by weight of a polyolefin resin, (B) 2 to 5 parts by weight of an ethylene-vinyl acetate copolymer, (C) 30 to 40 parts by weight of magnesium hydroxide,
(D) 4 to 6 parts by weight of red phosphorus, (E) 1 to 5 parts by weight of titanium oxide and (F) 1.5 to 3 parts by weight of carbon black,
An object of the present invention is to provide a polyolefin-based flame-retardant resin composition characterized in that the total amount of these components is 100 parts by weight, and a molded article formed by using this composition.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The polyolefin-based flame-retardant resin composition of the present invention contains the above components (A) to (F). Here, the polyolefin-based resin as the component (A) is not particularly limited, and any known polyolefin can be used. Examples thereof include polyethylene and polypropylene, and the measurement was performed at 230 ° C. and 2.16 kg. Melt flow rate (MFR) is 1 to 50 g /
Ten minutes of polypropylene are particularly preferred. MFR is 1
If it is less than g / 10 minutes, it is not suitable for injection molding and 50 g /
If it is longer than 10 minutes, the physical properties are reduced. The polyolefin-based flame-retardant resin composition of the present invention comprises the component (A) in an amount of 45%.
-55 parts by weight. If the amount of the component (A) is less than 45 parts by weight, there is a problem that the physical properties are reduced. On the other hand, if the amount exceeds 55 parts by weight, there is a disadvantage that the flame retardancy is reduced.

The ethylene-vinyl acetate copolymer as the component (B) is not particularly limited, but preferably has a vinyl acetate unit content of 10 to 30%, more preferably 20%.
A degree is optimal. Content of vinyl acetate unit is 1
If it is less than 0%, the flame retardancy decreases, and if it exceeds 30%, the physical properties and heat resistance decrease, and odor tends to be generated. The polyolefin-based flame-retardant resin composition of the present invention contains the component (B) in an amount of 2 to 5 parts by weight, preferably 3 to 4 parts by weight.
When the amount of the component (B) is less than 2 parts by weight, there is a problem that the flame retardancy is insufficient. On the other hand, when the amount exceeds 5 parts by weight, there arises a problem that physical properties and heat resistance are lowered.

The magnesium hydroxide used as the component (C) in the present invention has an average particle size of 0.1 to 20 μm, preferably
0.6 to 0.8 μm, and the density is 2.00 to 2.50
preferably it has a g / cm ^3, particularly preferably 2.36 g / cm ³ as the front and rear. When the average particle size is less than 0.1 μm, a problem that dispersion failure due to aggregation occurs and a predetermined composition cannot be obtained (hereinafter, this is referred to as “productivity (dispersion) failure”) tends to occur. If it exceeds 20 μm, inconvenience such as deterioration of flame retardancy and physical properties is likely to occur. The polyolefin-based flame-retardant resin composition of the present invention contains the component (C) in an amount of 30 to 40 parts by weight. When the component (C) is less than 30 parts by weight, there is a problem that flame retardancy is reduced,
If it exceeds 40 parts by weight, poor appearance such as whitening of the surface of the molded product occurs.

The red phosphorus used as the component (D) in the present invention has an average particle size of 1 to 50 μm, preferably 25 to 35 μm.
μm is preferred. If the average particle size is less than 1 μm, the problem of poor productivity (dispersion) is likely to occur,
If it exceeds μm, the inconvenience of insufficient flame retardancy is likely to occur. The red phosphorus is preferably a specially coated low-odor red phosphorus having a red phosphorus content of 92% or more. For example, red phosphorus whose surface is coated with a metal oxide, a thermosetting resin, or a mixture thereof is preferable. preferable. Here, examples of the metal oxide include titanium oxide, titanium-cobalt composite metal oxide, nickel oxide, cobalt oxide, and manganese oxide. Examples of the thermosetting resin include a melamine resin, a phenol resin, and an epoxy resin. And urea resins. The polyolefin-based flame-retardant resin composition of the present invention contains 4 to 6 parts by weight of the component (D).
If the amount of the component (D) is less than 4 parts by weight, there is a problem that the flame retardancy is reduced. If the amount exceeds 6 parts by weight, disadvantages such as deterioration of physical properties and poor odor are caused.

The titanium oxide used as the component (E) in the present invention is usually a commercially available rutile type TiO 2 for a resin additive.
₂ can be used, but the average particle size is 0.1 to 0.3μ
m and a density of 4.1 to 4.5 g / cm ³ of titanium oxide are preferred. If the average particle size of the titanium oxide is less than 0.1 μm, the problem of poor productivity (dispersion) tends to occur, and if it exceeds 0.3 μm, the inconvenience of reduced flame retardancy and reduced physical properties is likely to occur. Further, the density is 4.1 g / cm ³
If it is less than 4.5 g, problems such as a decrease in flame retardancy and physical properties are likely to occur. On the other hand, if it exceeds 4.5 g / cm ³ , inconvenience of poor productivity (dispersion) tends to occur. The polyolefin-based flame-retardant resin composition of the present invention comprises the component (E)
-5 parts by weight, preferably 4-5 parts by weight. (E)
If the amount of the component is less than 1 part by weight, there is a problem that the flame retardancy is reduced and the appearance is poor, and if it exceeds 5 parts by weight, the physical properties are reduced.

The polyolefin-based flame-retardant resin composition of the present invention further comprises carbon black as a component (F) in an amount of 1.5.
３3 parts by weight. Here, the carbon black may be any commercially available carbon black for a resin additive, or may be a powder or a master batch of a polyolefin. (F) The amount of the component is 1.
If the amount is less than 5 parts by weight, there is a problem that the flame retardancy is reduced. If the amount is more than 3 parts by weight, there is a disadvantage that physical properties and heat resistance are reduced.

The polyolefin-based flame-retardant resin composition of the present invention comprises, in addition to the components (A) to (F), a filler, a lubricant,
Additives such as antioxidants, antistatic agents and ultraviolet absorbers can be added as appropriate.

The polyolefin-based flame-retardant resin composition of the present invention can be produced by melt-kneading each component. For example, a high-speed stirrer represented by a Henschel mixer, a single-shaft or twin-shaft It can be manufactured by kneading using a continuous kneader, a roll mixer or the like alone or in combination. Further, the polyolefin-based flame-retardant resin composition of the present invention can be molded by various molding methods, for example, injection molding, extrusion molding, blow molding and the like, but particularly injection molding It is suitable for.

[0013]

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto. The substances used in the following examples and comparative examples are as follows. Polypropylene (abbreviated as PP) A: Idemitsu Polypro J465HBP: Melt index (abbreviated as MI) = 5 g / 10 min B: Idemitsu Polypro J785H: MI = 10 g / 10 min Ethylene-vinyl acetate copolymer (abbreviated as EVA) Nippon Unicar Co., Ltd., trade name NUC-3461 Magnesium hydroxide: 0.7 μm average particle diameter Red phosphorus: Rin Kagaku Kogyo Co., Ltd., trade name Nova Excel 140 Titanium oxide: 0.2 μm average particle diameter Carbon black: Dainichisei Chemical name: PPM77255 (30% masterbatch)

Examples 1-2 and Comparative Examples 1-8 Each component shown in Table 1 was prepared by using a twin-screw kneader (trade name: PCM45II manufactured by Ikegai Iron & Steel Co., Ltd.) at a barrel temperature of 160 ° C.
The composition was prepared by kneading at ~ 240 ° C and pelletized using strand cut. The composition pellets thus obtained were subjected to a cylinder temperature of 1 using an injection molding machine (trade name: FE-120, PS-40) manufactured by Nissei Plastic Industry Co., Ltd.
A test piece was prepared by injection molding at 90 to 210 ° C. and a mold temperature of 50 ° C., and its characteristics were evaluated by the following evaluation methods. The results are shown in Table 2. Flame retardancy evaluation (UL94) Testing machine: HVUL plastic, UL manufactured by Atlas
Flame Test Chamber Test Methods: Vertical burn tests were performed on 1/8 inch, 1/16 inch and 1/32 inch (thickness) according to Underwriters Laboratory Subject 94. Tensile strength Measured according to ASTM D638. Izod impact strength Measured according to ASTM D256. Flexural strength Measured according to ASTM D790. Odor At the time of kneading, molding and sensory evaluation by humans was performed.

[0015]

[Table 1]

[0016]

[Table 2]

[0017]

[Table 3]

[0018]

The resin composition of the present invention exhibits a high flame retardancy of up to 1/32 inch in a UL94 flame retardancy test, has a low odor during granulation, molding and other processing, and has a low moldability. Excellent, especially with fluidity suitable for injection molding, home appliances,
Internal parts that require flame retardancy, such as in the automotive field, for example,
It is useful for the production of various molded products such as connectors, substrate holders, and other exterior materials that are not caught by appearance and color. Moreover, the molded article obtained by using the resin composition of the present invention is odorless, and is excellent in flame retardancy and various physical properties.

Continued on front page (51) Int.Cl. ⁶ Identification symbol FI // (C08L 23/12 23:08) (C08L 23/12 31:04)

Claims (9)

[Claims] 1. A polyolefin-based resin (A) 45 to 55
Parts by weight, (B) 2 to 5 parts by weight of an ethylene-vinyl acetate copolymer, (C) 30 to 40 parts by weight of magnesium hydroxide,
(D) 4 to 6 parts by weight of red phosphorus, (E) 1 to 5 parts by weight of titanium oxide and (F) 1.5 to 3 parts by weight of carbon black,
A polyolefin-based flame-retardant resin composition, wherein the total amount of these components is 100 parts by weight. 2. The polyolefin resin of the component (A),
2. The polyolefin-based flame-retardant resin composition according to claim 1, wherein the melt flow rate (MFR) measured at 230 [deg.] C. and 2.16 kg is polypropylene of 1 to 50 g / 10 min. 3. The polyolefin-based flame retardant according to claim 1, wherein the ethylene-vinyl acetate copolymer as the component (B) is an ethylene-vinyl acetate copolymer having a vinyl acetate unit content of 10 to 30%. Resin composition. 4. The magnesium hydroxide of the component (C) has an average particle size of 0.1 to 20 μm and a density of 2.0 to 2.50 g / g.
The polyolefin-based flame-retardant resin composition according to claim 1, wherein the composition is magnesium hydroxide having a size of cm ³ . 5. The red phosphorus component (D) has an average particle size of 1 to 5.
The polyolefin-based flame-retardant resin composition according to claim 1, which is a specially coated low-odor red phosphorus having a red phosphorus content of 0 µm and a red phosphorus content of 92% or more. 6. The titanium oxide as the component (E) has an average particle size.
The polyolefin-based flame-retardant resin composition according to claim 1, which is titanium oxide having a density of 0.1 to 0.3 µm and a density of 4.1 to 4.5 g / cm ³ . 7. The carbon black of component (F) is a powder or a master batch of polyolefin.
The polyolefin-based flame-retardant resin composition according to the above. 8. A flame retardant level of 1/32 inch V-0
The polyolefin-based flame-retardant resin composition according to claim 1, which is a (UL94 flame-retardant test). 9. A molded article obtained by molding using the resin composition according to claim 1. Description: