JPH01299849A - Flame-retarding polyolefin resin composition - Google Patents

Abstract

PURPOSE:To make it possible to obtain a molding prevented from undergoing blooming of a flame retardant and having a good surface appearance, by mixing a polyolefin resin with a halogen flame retardant surface-coated with an inorganic oxide. CONSTITUTION:1-50 pts.wt. halogenous flame retardant (e.g., decabromodiphenyl ether or tetrabromobisphenol A dibromopropyl ether) surface-coated with an inorganic oxide such as Sb2O3, SiO2 or TiO2 is added to 100 pts.wt. polyolefin resin such as polyethylene, polypropylene or a copolymer of ethylene with propylene or vinyl acetate to obtain a flame-retardant polyolefin resin composition. The amount of the inorganic oxide used is such that the weight ratio of the inorganic oxide to the halogenous flame retardant is 0.5-99.5-90/10, desirably, 2/98-50/50.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a flame-retardant polyolefin resin composition capable of suppressing blooming of a flame retardant and providing a molded article with a good surface appearance.

[Conventional technology]

Polyolefin resins have excellent electrical and mechanical properties, so they are widely used in electrical products, building materials, and the like. However, in recent years, there has been a strong demand for flame retardancy from the viewpoint of safety.

In polyolefin resins, halogen-based flame retardants are generally added to make them flame retardant.

Among these halogen-based flame retardants, aromatic flame retardants such as decabromodiphenyl ether, bis(tribromo)phenoxyethane, and bisphenol A halogenated alkyl ether include bis(tetraphthalimido)ethane, bis(dibromonorbornene-dicarboximide) ) It is especially prized because it has superior flame retardant effects and thermal stability compared to ethane and the like.

[Problem to be solved by the invention]

However, the aromatic halogen flame retardants mentioned above,
Due to its low affinity for polyolefins, flame retardants tend to bloom over time and deteriorate the surface appearance of molded products.

As a preventive measure, for example, JP-A-61-168643
No. 61-176647 discloses a method of adding an aliphatic carboxylic acid having a melting point of 60°C or less or a metal salt of the aliphatic carboxylic acid to a flame-retardant polyolefin resin composition. However, when these compositions are used at room temperature or above, the blooming prevention effect is not necessarily sufficient.

In addition, Japanese Patent Publication No. 7221/1983 discloses a method of treating flame retardants with a titanate coupling agent, but aromatic flame retardants containing halogens contain active hydrogen that reacts with the titanate coupling agent. In many cases, the blooming prevention effect cannot be said to be sufficient.

In view of the above circumstances, the present invention uses a halogen-based flame retardant with good flame retardant effect and thermal stability as described above, and provides a molded article with a good surface appearance without blooming. The purpose of the present invention is to provide a flame-retardant polyolefin resin composition that is moisturizing.

[Means to solve the problem]

As a result of intensive studies to achieve the above object, the present inventors have found that the blooming phenomenon can be significantly suppressed by coating the halogen flame retardant with a specific substance different from the titanate coupling agent. Having learned that this is possible, we have completed the present invention.

That is, the present invention relates to a flame-retardant polyolefin resin composition characterized in that it contains 1 to 50 parts by weight of a halogen flame retardant whose surface is coated with an inorganic oxide per 1.0 parts by weight of the polyolefin resin. It is.

[Structure and operation of the invention]

Polyolefin resins used in the present invention include polyethylene, polypropylene, polybutene, polymethylpentene, etc., as well as random combinations of ethylene and propylene, butene, vinyl acetate, ethyl acrylate, etc.
Examples include block polymers, graft polymers, and mixtures thereof.

Inorganic oxides used in the present invention include antimony oxides such as antimony trioxide and antimony pentoxide; silicates such as silicon dioxide, mica, talc, wollastonite, and sericite; carbonates such as calcium carbonate; Examples include titanium oxides such as titanium dioxide; zinc oxides such as zinc oxide and zinc borate; antimony trioxide, antimony pentoxide, silicon dioxide, and titanium dioxide are particularly preferably used.

Examples of the halogen flame retardants used in the present invention include decabromodiphenyl ether, octabromodiphenyl ether, bis(tribromo)phenoxyethane, bis(pentabromo)phenoxyethane, tetrabromobisphenol A1, dibromopropyl ether of tetrabromobisphenol A, and tetrabromobisphenol A1. Examples include halogenated aromatic compounds such as bisphenol S; halogenated alicyclic compounds such as hexabromocyclododecane; halogenated alkyl cyanurates such as tris(dibromopropyl) isocyanurate; (wherein R is an oxygen atom or an alkyldioxy group, X is a halogen atom, and l1m is an integer of 3 to 5) and/or the following general formula; , R, is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms or a halogenated alkyl group, R2 is an alkylene group having 1 to 4 carbon atoms, X is a halogen atom, n and o are 1
(an integer of 3 to 3) is preferably used.

In the present invention, the surface of the above-mentioned halogen-based flame retardant is coated with the above-mentioned inorganic oxide, and the amount of inorganic oxide used at that time is such that the weight ratio of the inorganic oxide to the halogen-based flame retardant is 0.
5/99.5~90/10. Preferably from 2/98
It is preferable to set it within the range of 50,150. If the amount of inorganic oxide used is too small, the blooming prevention effect will not be sufficiently exhibited, and if it is too large, the resulting resin composition will not exhibit practical flame retardancy.

A halogen flame retardant whose surface is coated with an inorganic compound can be obtained by the following method. For example, antimony trichloride, sodium antimonate, etc. are dissolved or dispersed in a solvent, a halogen flame retardant is dispersed therein, and then a coating layer of antimony trioxide or antimony pentoxide is applied to the above flame retardant using an acid-base reaction. This is a method of forming on the surface of.

In addition, silicate ester, titanyl sulfate, etc. are dissolved or dispersed in a solvent, a halogen flame retardant is dispersed therein, and then thermally hydrolyzed to form a coating layer of silicon dioxide or titanium dioxide on the surface of the flame retardant. This is a method of forming.

The flame-retardant polyolefin resin composition of the present invention is prepared by adding 1 part by weight of a halogen-based flame retardant whose surface is coated with an inorganic oxide obtained by such a method to 100 parts by weight of the polyolefin resin.
It is characterized by containing up to 50 parts by weight, preferably 2 to 25 parts by weight. If the halogen flame retardant whose surface is coated with an inorganic oxide is less than 1 part by weight, no practical flame retardant effect can be obtained, while if it is more than 50 parts by weight, the processability of the resin will be poor and the strength of the molded product will be reduced. In addition to this, it is also an economic problem.

In addition, in the case of a so-called mask-batch containing a high concentration of flame retardant, 50 to 50 parts by weight of the halogen flame retardant whose surface is coated with the above inorganic oxide is added to 100 parts by weight of the polyolefin resin.
It can be blended up to 300 parts by weight. When used, this masterbatch is diluted with a polyolefin resin to form a so-called compound having a flame retardant content within the above range.

The flame-retardant polyolefin resin composition of the present invention contains polyolefin resin and a halogen-based flame retardant whose surface is coated with an inorganic oxide as essential components, as well as antimony trioxide, antimony pentoxide, zinc borate, zirconium oxide, etc. By further blending a combustion aid, a higher degree of flame retardant polyolefin resin composition can be obtained.

The blending amount of these flame retardant aids is 100% polyolefin resin.
It is generally 0.5 to 25 parts by weight. In addition, when setting it as what is called a masterbatch containing a flame retardant and a flame retardant aid in high concentration, the compounding amount of the said flame retardant aid is 25-200 weight parts with respect to 100 weight part of polyolefin resins.

Furthermore, in the flame-retardant polyolefin resin composition of the present invention, the halogen-based flame retardant whose surface is coated with an inorganic oxide may be further surface-treated with a silane coupling agent, a titanate coupling agent, or the like. Instead of performing this surface treatment, the above-mentioned coupling agent may be added as one of the additive components at the time of kneading and preparing the composition.

Furthermore, antioxidants, ultraviolet absorbers, antistatic agents, mold release agents, dispersants, pigments, fillers, etc. may be added to the flame-retardant polyolefin resin composition of the present invention, if necessary. can.

The flame-retardant polyolefin resin composition of the present invention can be produced using a melt-kneading method as in the case of general polyolefin resin compositions. For example, after mixing the above-mentioned polyolefin resin, a halogen flame retardant whose surface is coated with an inorganic oxide, and various additives in a Henschel mixer, a Banbury mixer, a kneader,
The mixture may be kneaded using a twin-screw extruder, a single-screw extruder, or the like at a temperature higher than the plasticizing temperature of the polyolefin resin to obtain a masterbatch or a resin composition (compound) at a normal concentration.

In the case of a masterbatch, the mixture is further mixed with a polyolefin resin for dilution and then melt-kneaded using a roll mill, single screw extruder, etc. to obtain a compound.

〔Effect of the invention〕

According to the present invention, blooming of the flame retardant is suppressed.
Since it is possible to obtain a flame-retardant polyolefin resin composition that can provide a molded article with a good surface appearance, it can greatly contribute to the expansion of applications for the exterior of electrical products, building materials, etc.

〔Example〕

Next, examples of the present invention will be described in more detail.

Example 1 After dissolving 68 g of antimony trichloride in 1,000 g of water, 100 g of decabromodiphenyl ether was dispersed therein. After boiling this for 2 hours while stirring, 6.2 g of sodium carbonate was further added and boiled for 30 minutes. After filtering the precipitate and washing with 3,000 g of water, the temperature was increased to 110°C.
to obtain decabromodiphenyl ether whose surface was coated with antimony trioxide. The bromine content was measured and the weight ratio of antimony trioxide to decabromodiphenyl ether was determined to be 29.8/70.2.

This was mixed with the formulation shown in MBI in Table 1 below (mixing unit is weight %), and using a kneader [manufactured by Toyo Seiki Seisakusho ■, Labo Plast Mill 30C150 type], the resin temperature was 230.
The mixture was kneaded at ℃ to obtain a masterbatch.

Next, this masterbatch was pulverized to a particle size of 1 to 2 mm, and then 10 parts by weight was added to 100 parts by weight of polypropylene (manufactured by Nippon Petrochemical Co., Ltd., Nisseki Polypro J620G), and this was extruded using an l-axis with a diameter of 20 mm. The mixture was melt-extruded at a resin temperature of 220 to 240° C. using a machine [Laboplast Mill 30C150 type manufactured by Toyo Seiki Seisakusho ■] and pelletized using a pelletizer to obtain a compound.

Example 2 The masterbatch obtained in Example 1 was pulverized to a particle size of 1 to 2 ml, and then 10 parts by weight was added to 100 parts by weight of a polyolefin elastomer (manufactured by Mitsui Petrochemical Industries Ltd., Milastomer 703ON), and the following examples were prepared. A compound was obtained in the same manner as in 1.

Example 3 52 g of sodium antimonate and 100 g of decabromodiphenyl ether were dispersed in 1,000 g of water. Furthermore, 40g of 35% by weight HCI was added and heated at 30°C for 3 hours.
Stirred. This precipitate was filtered, washed with 3.000 g of water, and then dried at 110°C to obtain decabromodiphenyl ether whose surface was coated with antimony pentoxide. The bromine content was measured and the weight ratio of antimony pentoxide to decabromodiphenyl ether was determined to be 29.1/
It was 70.9.

These were mixed according to the formulation shown in MB2 in Table 1 below, a masterbatch was prepared in the same manner as in Example 1, and a compound was obtained in the same manner as in Example 1 using this.

Example 4 A compound was obtained in the same manner as in Example 2 using the masterbatch obtained in Example 3.

Example 5 17.3 g of ethyl silicate was added to a mixed solution of water and methanol [water/methanol = 5/95 (weight ratio)] 1°000
In g? After dissolving, decabromodiphenyl ether 9
5g was added. This was boiled for 1 hour while stirring.

After filtering the precipitate, it was dried at 110°C to obtain decabromodiphenyl ether whose surface was coated with silicon dioxide. When the bromine content was measured and the weight ratio of silicon dioxide to decabromodiphenyl ether was determined, it was 4.8/
It was 95.2.

These were mixed in the formulation shown in MB3 in Table 1 below to prepare a masterbatch in the same manner as in Example 1, and further using this, a compound was obtained in the same manner as in Example 1.

Example 6 A compound was obtained in the same manner as in Example 2 using the masterbatch obtained in Example 5.

Example 7 Titanyl sulfate aqueous solution (titanyl sulfate 1% by weight) 1.00
0g to 76g decabromodiphenyl ether and 11g tetrabromobisphenol A dibromopropyl ether
9g was dispersed. This was boiled for 2 hours while stirring.

After filtering the precipitate and washing with 3.000 g of water,
It was dried at 0° C. to obtain a material in which a mixture of 80% by weight of decabromodiphenyl ether and 20% by weight of tetrabromobisphenol A dibromopropyl ether was coated with titanium dioxide. The bromine content was measured and the weight ratio of titanium dioxide to the above two types of halogen flame retardants was found to be 4.6/95.4.

These were mixed in the formulation shown in MB4 in Table 1 below, a masterbatch was prepared in the same manner as in Example 1, and a compound was obtained in the same manner as in Example 1 using this masterbatch.

Example 8 A compound was obtained in the same manner as in Example 2 using the masterbatch obtained in Example 7.

Comparative Example 1 Decabromodiphenyl ether was mixed in the formulation of MB5 shown in Table 1 below, a masterbatch was prepared in the same manner as in Example 1, and a compound was obtained in the same manner as in Example 1 using this.

Comparative Example 2 A compound was obtained in the same manner as in Example 2 using the masterbatch obtained in Comparative Example 1.

Comparative Example 3 80% by weight of decabromodiphenyl ether and 20% by weight of decabromobisphenol A dibromopropyl ether
A master batch was prepared in the same manner as in Example 1, and a compound was obtained in the same manner as in Example 1 using this mixture.

Comparative Example 4 Using the masterbatch obtained in Comparative Example 3, a compound was obtained in the same manner as in Example-2.

Flammability and blooming were evaluated using the compounds of Examples 1 to 8 and Comparative Examples 1 to 4 in the following manner. These results were as shown in Table 2 below.

Flammability evaluation method〉 The compound was press-molded at 190℃, and the width was 4 inches.
A sheet with a length of 14 inches and a thickness of 0.2 inches was prepared,
Evaluation was performed using the MVSS method. The MVSS acceptance criteria is when the following conditions (1) and (2) occur when a flame at a height of 1.5 inches is brought into contact with the lower surface of the center of the free end of the sheet for 15 seconds.

■ Combustion stops within 60 seconds and does not burn more than 2 inches ■ Burning speed calculated by the following formula is slower than 4 inches/minute B = D / T B: Burning speed (inch 7 minutes) D: Combustion Distance (inch) <Blooming evaluation method> The compound was passed through an l-shaft extruder with a diameter of 20 mm [Toyo Seiki Seisakusho side type, Labo Plast Mill 30C150 type].
A film with a thickness of 100 μm is produced under conditions of a resin temperature of 220 to 230° C. and a production rate of 3 rn/min.

After this film was left in an oven at 60° C. for 7 days, blooming was evaluated by gloss difference and visual judgment. Gloss difference can be measured using a variable angle photometer [Suga Test Machine side, UG
V-50 type] at an incident angle and a light receiving angle of 45° C., and calculated using the following formula. Note that the smaller the difference in gloss, the better the blooming improvement effect.

Visual Judgment Criteria ◎: No blooming ○: Little blooming Δ: Much blooming ×: Very much blooming Table 1 ■, Milastomer 703 (INJ) Example 1~
It can be seen that all of the flame-retardant polyolefin resin compositions of No. 8 have good flame retardancy, and the blooming phenomenon of the flame retardant is significantly suppressed.

Patent applicant: NOF Corporation

Claims (1)

[Claims] (1) A flame-retardant polyolefin resin composition containing 1 to 50 parts by weight of a halogen flame retardant whose surface is coated with an inorganic oxide based on 100 parts by weight of the polyolefin resin.