JP2000302984A - Flame-retardant resin composition and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition easily formable and processable and free from halogen by including a specific maleic anhydride-modified elastomer, specific resin and inorganic flame retardant without increasing the melt viscosity of the composition despite including the inorganic flame retardant. SOLUTION: This composition is obtained by including (A) an amine- crosslinked maleic anhydride-modified elastomer at <=50 pts.wt., preferably 10-50 pts.wt., based on 100 pts.wt. of the component (B), (B) a resin compatible with the component A and (C) an inorganic flame retardant. The amine- crosslinking is preferably done using a polyamine. As for the polyamine, normally a polyamine used as a curing agent in an epoxy adhesive of normal temperature curing-type can be used and especially preferably a modified aliphatic polyamine (e.g. diethylenetriamine) is used. The amount of the polyamine to be used for the amine-crosslinking is preferably 0.5-5 pts.wt. based on 100 pts.wt. of the component B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flame-retardant resin composition, and more particularly, to a non-halogen flame-retardant resin composition for flexible cords that does not generate harmful halogen-based gas upon burning.

[0002]

2. Description of the Related Art In recent years, awareness of global environmental preservation has been increasing, and regulations on substances that generate halogen have been reinforced. For example, polyvinyl chloride is frequently used as a covering material for electric wires. However, since toxic chlorine gas and chlorine compounds are generated during incineration, polyvinyl chloride is a halogen-free resin such as polyethylene (PE) or polyethylene (PP). It is being replaced by olefin resins such as Also, inorganic flame retardants such as magnesium hydroxide and aluminum hydroxide, which are halogen-free flame retardants, are increasingly used as flame retardants. But,
In a high-temperature use environment, if the temperature exceeds the melting point of the resin used, the resin naturally melts and the coated electric wire cannot withstand use.

Therefore, it is conceivable to use a high melting point resin or a highly crystalline resin. However, if an inorganic flame retardant is added to these resins, the physical properties are greatly reduced. In order to suppress the deterioration in physical properties, an inorganic flame retardant is changed to a high melting point resin or a high melting point resin by using an amorphous polymer such as an ethylene-vinyl acetate copolymer (EVA) or an ethylene-ethyl acrylate copolymer (EEA). A technique of blending with a crystalline resin has been adopted. However, the melting point of amorphous polymers is very low. Therefore, a method has been proposed in which an amorphous polymer is thermally stabilized by a crosslinking method such as electron beam crosslinking or water crosslinking.

[0004]

Once a polymer compound has been crosslinked, it cannot be thermally melted and therefore cannot be recycled, and it must be incinerated after disposal. In order to overcome this drawback, resin products produced by dynamic crosslinking have been developed, and are commercially available, for example, as Santoprene from Monsanto. This product is
It is obtained by dispersing crosslinked EPDM (ethylene-propylene-diene copolymer) fine particles in a polypropylene matrix. Also, Japanese Patent Application Laid-Open No. 6-31
No. 3067 discloses a thermoplastic elastomer in which fine particles such as crosslinked maleic anhydride-modified SEBS are dispersed in an unmodified thermoplastic resin or an elastomer as a matrix. However, there is no mention of a system to which an inorganic flame retardant has been added.

[0005] By partially cross-linking the resin, sufficient thermal properties can be imparted to the resin. However, when magnesium hydroxide or aluminum hydroxide, which is an inorganic flame retardant in consideration of environmental protection, is used as the flame retardant, the inorganic flame retardant has a low flame retarding effect and needs to be added in a large amount. When a large amount of the inorganic flame retardant is added, the physical properties decrease. However, it is necessary to increase the number of crosslinked portions in order to compensate for the decrease in the physical properties. However, when the number of crosslinked portions increases, the melt viscosity increases, and a problem arises that molding cannot be performed.

Accordingly, an object of the present invention is to provide a halogen-free flame-retardant resin composition which does not increase the melt viscosity even when an inorganic flame retardant is added, is easy to mold, and has a halogen-free flame retardant resin composition. It is.

[0007]

According to the present invention, an object of the present invention is to provide a flame-retardant resin composition comprising a maleic anhydride-modified elastomer, a resin compatible with the modified elastomer, and an inorganic flame retardant. The modified elastomer comprises an amine-crosslinked flame-retardant resin composition, and a maleic anhydride-modified elastomer mixed with an inorganic flame retardant, and mixed with a resin having compatibility with the modified elastomer. This is achieved by a method for producing a flame-retardant resin composition, comprising dispersing a modified elastomer and the inorganic flame retardant and subjecting the modified elastomer to amine crosslinking.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The maleic anhydride-modified elastomer used in the present invention is EVA, EEA, PE, P
P is an elastomer modified with maleic anhydride, and various elastomers are commercially available (for example, VR103 and AR20 manufactured by Du Pont-Mitsui Chemicals Co., Ltd.).
1 etc.).

Examples of resins compatible with the above-mentioned modified elastomer include polyethylene (low-density polyethylene, high-density polyethylene, etc.), polypropylene, EVA, EE
A, styrene-based elastomers (SEBS, SEPS, etc.) can be used.

The amount of the modified elastomer is 50 parts by weight or less, preferably 10 to 50 parts by weight, based on 100 parts by weight of the resin compatible with the modified elastomer. If the amount of the modified elastomer exceeds the above upper limit, the fluidity of the composition becomes extremely poor, and molding becomes difficult.

As the inorganic flame retardant, a conventionally used inorganic flame retardant can be used, and preferable examples are magnesium hydroxide, aluminum hydroxide, calcium hydroxide and the like. The amount of the inorganic flame retardant is usually 50 to 200 parts by weight, preferably 100 to 200 parts by weight, based on 100 parts by weight of the resin compatible with the modified elastomer. When the amount of the inorganic flame retardant exceeds the above upper limit, the initial physical properties of the composition decrease. As a flame retardant aid, zinc borate, red phosphorus, silica, and the like can be blended.

The flame-retardant resin composition of the present invention is obtained by mixing an inorganic flame retardant with the above-mentioned modified elastomer, mixing a resin having compatibility with the above-mentioned modified elastomer, and adding the above-mentioned modified elastomer and the inorganic flame retardant. It can be manufactured by dispersing and then subjecting the modified elastomer to amine crosslinking.

Usually, the amine crosslinking is performed using a polyamine. Here, the polyamine includes a diamine.
As the polyamine, a polyamine which is usually used as a curing agent in a cold-setting epoxy adhesive can be used. Especially, a modified aliphatic polyamine is preferable. Specific examples of the modified aliphatic polyamine include diethylene triamine,
Triethylenetetramine, tetraethylenepentamine,
Dipropylenediamine, diethylaminopropylamine, N-aminoethylpiperazine, mensendiamine,
Isophorone diamine.

The polyamine is preferably 1000 mPa
Has a viscosity of s or less. If the viscosity is higher than this, the reactivity decreases and the handleability deteriorates.

The amount of the polyamine used for the amine crosslinking is
The total of the modified elastomer and the compatible resin is 1
0.5 to 5 parts by weight, preferably 0.1 to 100 parts by weight.
5 to 3 parts by weight.

The amine crosslinking may be carried out at a temperature about 20 ° C. higher than the highest melting point of the resins.

[0017]

Next, the present invention will be specifically described with reference to examples and comparative examples. Example 1-2 and Comparative Example 1-2 A resin composition was prepared using the components shown in Table 1 in the amounts shown in the same table. First, a modified elastomer (MAH-EVA or MAH-EEA) and magnesium hydroxide were blended, and a matrix polymer (ethylene-propylene block copolymer or high-density polyethylene) and an antioxidant were blended and sufficiently kneaded. Next, a polyamine was added, and the mixture was heated at 180 ° C. for 1 minute or more using a pressure kneader to perform crosslinking.

The obtained resin composition was coated on a conductor (size 0.75 sq) to a thickness of 0.8 mm by extrusion. At this time, the composition which could be extruded has good moldability.
Was evaluated. Further, the tensile elongation and the heat deformability of each resin composition were evaluated. The tensile elongation was measured by the following method. A sheet having a thickness of 1 mm was created by press molding, and a sample punched out with dumbbell No. 3 was marked with a 20 mm mark in accordance with JIS C3005.
A tensile test was performed at a speed of mm / min. When it had a breaking elongation of 200% or more, it was evaluated as “good”. The heat deformability was evaluated as follows. A sheet having a thickness of 2 mm was prepared in the same manner as above, and a sample cut to 35 × 35 mm was placed on a semi-cylinder having a diameter of 10 mm, and a metal flat plate was placed on the top of the sample so as to sandwich the sample and the semi-cylinder. A load of 5 N (including the weight of the metal flat plate) was applied at 120 ° C. in the thickness direction of the sample for 30 minutes. When the subsequent reduction rate of the thickness was 40% or less, it was evaluated as “good”. Table 1 shows the results.

[0019]

[Table 1] Note: 1) MK640 manufactured by Tokuyama Corporation. 2) 5305E manufactured by Mitsui Chemicals, Inc. 3) VR103 made by Mitsui Dupont Chemical Co., Ltd. 4) Mitsui Dupont Chemical Co., Ltd. AR201. 5) Kisuma 5 manufactured by Kyowa Chemical Industry Co., Ltd. 6) Tominox TT manufactured by Yoshitomi Pharmaceutical Co., Ltd. 7) Q612 manufactured by Mitsui Chemicals, Inc.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Ryo Senoo 1-14 Nishisuehiro-cho, Yokkaichi-shi, Mie F-term in Sumitomo Wiring Systems Co., Ltd. 4F070 AA13 AA15 AA28 AA32 AB03 AB08 AB09 AB16 AC13 AC46 AE03 AE07 AE08 GA10 4J002 BB031 BB061 BB071 BB121 BB212 BP011 BP031 DE076 DE086 DE146 FD136

Claims (6)

[Claims] 1. A flame-retardant resin composition comprising a maleic anhydride-modified elastomer, a resin compatible with the modified elastomer, and an inorganic flame retardant, wherein the modified elastomer is amine-crosslinked flame-retardant Resin composition. 2. The flame-retardant resin composition according to claim 1, wherein the amine crosslinking is performed with a polyamine. 3. The flame-retardant resin composition according to claim 2, wherein the polyamine is a modified aliphatic polyamine. 4. The flame-retardant resin composition according to claim 1, wherein the amount of the maleic anhydride-modified elastomer is 50 parts by weight or less based on 100 parts by weight of the total of the modified elastomer and the compatible resin. . 5. The amount of the polyamine used for the amine crosslinking is:
Total 10 of the modified elastomer and the compatible resin
The flame-retardant resin composition according to claim 1, wherein the amount is 0.5 to 5 parts by weight with respect to 0 parts by weight. 6. A modified elastomer obtained by mixing an inorganic flame retardant with a maleic anhydride-modified elastomer and mixing a resin having compatibility with the modified elastomer to disperse the modified elastomer and the inorganic flame retardant. A method for producing a flame-retardant resin composition, comprising subjecting a compound to amine crosslinking.