JPH02284940A - Fire retardant resin composition - Google Patents

Abstract

PURPOSE:To obtain fire retardant resin composition having excellent fire retardancy, procedsability and mechanical strength containing polypropylene, glass fiber, fibrous magnesium hydroxide and/or fibrous xonotlite and acid- modified polyolefin. CONSTITUTION:(A) 20-60wt.% polypropylene is mixed with (B) 5-40wt.% glass fiber, preferably E-glass fiber treated the surface with aminosilane-based coupling agent having 6-15mum average diameter and 0.5-6mm cut length, (C) 15-60wt.% fibrous magnesium hydroxide and/or fibrous xonotlite expressed by formula I or formula II (X<=6) having 0.1-3mum, preferably 0.2-1mum average tiber diameter and 10-200, preferably 15-100 aspect ratio. Then, 100 pts.wt. resultant resin composition is mixed with (D) 0.1-10 pts.wt. acid-modified polyolefin (preferably modified with maleic acid anhydride, etc.) to afford the aimed resin composition.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a flame-retardant resin composition, and more specifically, the present invention relates to a flame-retardant resin composition. The present invention relates to a flame-retardant resin composition which has excellent and high mechanical strength and can be suitably used for various purposes such as, for example, a molding material for automobile parts and a molding material for electronic device parts.

[Prior Art and Problems to be Solved by the Invention] For example, there is an increasing demand for non-halogenated resin compositions used as molding materials for automobile parts, electronic device parts, etc., which do not generate halogen gas during combustion.

As a method of making resin flame retardant without using halogen-based flame retardants, for example, a method of blending a large amount of granular magnesium hydroxide or aluminum hydroxide into polyolefin resin is known (Japanese Patent Application Laid-open No. 57-10898
No. 58-79040, No. 59-2023
Publication No. 43, Publication No. 80-110738, Publication No. 80-1
No. 47483, No. 61-34038, No. 61
(See Publication No. 243805, etc.).

However, although these methods can achieve the goal of flame retardancy to some extent, they require a significant increase in mechanical strength such as tensile strength and bending strength due to the inclusion of a large amount of hydroxide-based particulate inorganic filler. The disadvantage is that it cannot be avoided.

The present invention has been made based on the above circumstances.

The purpose of the present invention is to create a material that does not generate halogen gas during combustion, has excellent flame retardancy, moldability, etc., and has high mechanical strength, such as a molding material for automobile parts or a molding material for electronic device parts. It is an object of the present invention to provide a flame-retardant resin composition that can be suitably used for various purposes such as.

[Means for Solving the Problems] In order to solve the above problems, the present inventor has made extensive studies and found that polypropylene, glass fibers, fibrous magnesium hydroxide of a specific shape and/or xonotlite, and acid A resin composition formed by blending modified polyolef vein in a predetermined ratio does not generate halogen gas when burned, has excellent flame retardancy and moldability, and has high mechanical strength. With this discovery, we have arrived at the present invention.

The composition of the present invention is: (A) 20 to 80% by weight of polypropylene (B) Glass fiber! 15-40% by weight, and (
C) fibrous magnesium hydroxide and/or c<m! l
Based on 100 parts by weight of a composition containing 15 to 60% by weight of xonotrite, 0.0% of (D) acid-modified polyolefin is added.
This is a flame-retardant resin composition characterized in that it contains 1 to 10 parts by weight.

The flame retardant resin composition of the present invention will be explained in detail below.

Regarding component (A) In the flame retardant resin composition of the present invention, polypropylene is used as component (A).

Examples of the polypropylene include propylene homopolymers, psepylene-ethylene block copolymers and random copolymers, and propylene-ethylene-diene compound copolymers.

Among these, propylene homopolymers having a melt index of usually 8 or more, preferably 10, and propylene-ethylene block copolymers having an ethylene unit content of 7% by weight or less are suitable.

These may be used alone or in combination of two or more.

In the flame retardant resin composition of the present invention, glass fiber is used as the component (B).

There is no particular restriction on the type of glass fiber, and any of those conventionally used for glass fiber reinforced thermoplastic resins, such as E glass fiber, A glass fiber, C glass fiber, etc., may be used. Although these may be used in combination, E glass fiber is preferred.

The average diameter of the glass fibers is usually 5 to 20 gm.
, preferably 6 to 15 g, m, and the cut length is:
Normally, it is desirable that the intestine is in the range of 0.05 to 10 layers, preferably 0.5 to 6 layers, particularly preferably 1 to 3 layers, and the average diameter is less than 571 m or the cut length is 10 layers. If the diameter exceeds 20 JLm or the cut length is 0.
．． 05 Maro■ If the material is not swirled, the improvement in mechanical strength and rigidity may not be sufficient.

The glass fibers can be used as they are, but in order to improve their affinity with the matrix resin and further increase their mechanical strength, they can be treated with agents that are commonly used as surface treatment agents for glass fibers, such as silane coupling. It is also possible to use those surface-treated with various coupling agents such as titanate coupling agents, aluminum coupling agents, chromium coupling agents, and boron coupling agents.

Among these various coupling agents, preferred are:
For example, vinyl silane coupling agents [e.g. vinyltris(2-methoxyethoxy)silane], aminosilane coupling agents (e.g. γ-aminopropyltriethoxysilane), epoxysilane coupling agents (e.g.
γ-glycidoxypropyltrimethoxysilane), acrylic silane coupling agents (e.g. γ-methacryloxypropyltrimethoxysilane), and particularly preferred are aminosilane coupling agents. be.

In the flame retardant resin composition of the present invention, fibrous magnesium hydroxide and/or fibrous xonotlite are used as component (C).

As the fibrous magnesium hydroxide, those having an average fiber diameter and an aspect ratio within the following ranges can be suitably used.

The fibrous xonotlite is composed of xonotlite, which is a calcium silicate hydrate represented by the following formula: % formula % (wherein, X is a number less than 6).

The above-mentioned fibrous magnesium hydroxide and/or fibrous xonotlite has an average fiber! l diameter is usually (1,1~
3 pm, preferably 0.2-1 gm. If the average fiber diameter is less than 0.1 Bm, the bulk specific gravity may become too small, making kneading difficult. On the other hand, if it exceeds 3ILm, mechanical strength may decrease.

The m#I magnesium hydroxide and/or fibrous xonotlite usually has an aspect ratio of 10 to 2.
00, preferably 15-100. If this aspect ratio is less than 10, sufficient mechanical strength may not be obtained. On the other hand, if it exceeds 200, the bulk specific gravity becomes too small and crosstalk may become difficult.

In the flame-retardant resin composition of the present invention, the fibrous magnesium hydroxide and/or fibrous xonotlite are
It can also be used after being granulated to have an average particle diameter of 0.1 to 51 and a bulk specific gravity of 0.15 to 0.4.

When using the fibrous magnesium hydroxide and/or fibrous xonotrite in granules, if the average particle diameter and bulk specific gravity are outside the above range, it is difficult to knead with a single-screw extruder, twin-screw extruder, etc. Therefore, the m-fibers must be filled one after another using a roll or a Banbury mixer, which may result in significant destruction of the m-fibers and a decrease in strength.

As a method of granulation, for example, the fibrous magnesium hydroxide and/or fibrous xonotlite are placed in a stirring tank containing a predetermined amount of water, the aggregates are crushed, and the water is separated, and then A method can be adopted in which a gel-like product is extruded through holes having a diameter of 0.1 to 5 intestinal layers to form granules, and then dried in an oven or the like.

The flame retardant resin composition of the present invention comprises the component (A).

It consists of a composition consisting of component (B) and component (C), and component (D), which will be described in detail later.

In the composition, the blending ratio of the polypropylene (^)I&min is 20 to 60% by weight, preferably 35% by weight.
~55% by weight. If this proportion is less than 20% by weight, the fluidity may decrease, the appearance may deteriorate, and the impact strength may not be sufficient. On the other hand, if it exceeds 60% by weight, Ja mechanical strength and rigidity may decrease, and flame retardancy may deteriorate.

In the composition, the blending ratio of the glass fiber as component (B) is 5 to 40% by weight, preferably 10 to 30% by weight. If this proportion is less than 5% by weight, mechanical strength and rigidity may be insufficient. On the other hand, if it exceeds 40% by weight, fluidity may decrease and the appearance may deteriorate.

In the composition, the blending ratio of the fibrous magnesium hydroxide and/or fibrous xonotlite as component (C) is 15 to 60% by weight, preferably 20 to 55% by weight. If this proportion is less than 15% by weight, the flame retardant effect may not be sufficiently exhibited. On the other hand, 80% by weight
Exceeding this may result in decreased fluidity, poor appearance, and a decrease in impact strength.

Regarding component (D), the flame-retardant resin composition of the present invention includes the above-mentioned component (A), (B)
0.1 to 10 parts by weight of an acid-modified polyolefin as component (D) is further blended with 100 parts by weight of the composition consisting of component (C) and component (C).

As the acid-modified polyolefin, for example, a polyolefin modified with an unsaturated carboxylic acid or a derivative thereof can be suitably used.

The polyolefin used in the acid-modified polyolefin is preferably a polypropylene resin such as a propylene homopolymer, a propylene-ethylene block copolymer, or a random copolymer.

Examples of the unsaturated carboxylic acid used in the acid-modified polyolefin include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid, sorbic acid, mesaconic acid, and angelic acid.

Further, examples of the derivatives of the unsaturated carboxylic acid include acid anhydrides, esters, amides, imides, metal salts, and the like. More specifically, examples include maleic anhydride, itaconic anhydride, citraconic anhydride, methyl acrylate, methyl methacrylate, ethyl acrylate, butyl acrylate, maleic acid monoethyl ester, acrylamide, maleic acid monoamide, maleimide. , N-butylmaleimide, sodium acrylate, sodium methacrylate, and the like.

Among these, acrylic acid and maleic anhydride are preferred.

There is no particular restriction on the method of modifying the polyolefin with the unsaturated carboxylic acid or its derivative,
For example, any of various known methods can be employed.

For example, polyolefin and maleic anhydride,
In the zero reaction, which can be carried out by adding a radical initiator and heating in the presence or absence of a solvent, other vinyl monomers such as styrene or rubbers such as liquid rubber or thermoplastic rubber may be coexisting. It's okay.

The acid addition amount of the acid-modified polyolefin is usually 0.1
-15% by weight, preferably 0.5-10% by weight.

The blending ratio of the acid-modified polyolefin is as follows:
The amount is usually 0.1-10 parts by weight, preferably 1-5 parts by weight per 00 parts by weight. If this proportion is less than 0.1 ii parts, the improvement in mechanical strength may not be sufficient. On the other hand, even if the amount exceeds 10 parts by weight, the corresponding effect may not be achieved, and mechanical strength may deteriorate on the contrary.

Fire Pentagonal (A) component, (B) component, (C) component and (D)
The flame retardant resin composition of the present invention consisting of the following components usually has a melt index (MI) of 3 to 20 g/10 minutes,
Preferably it is 4-15 g/10 minutes.

If this melt index is less than 3g710 minutes,
Fluidity may decrease and the appearance may become extremely poor.

On the other hand, if it exceeds 20 g/10 minutes, the impact strength may decrease.

In order to adjust the melt index to the above range, organic peroxides such as alkyl hydroperoxides, dialkyl peroxides, diacyl peroxides, peracid esters, and alkylidene peroxides can be used.

The amount of the organic peroxide to be used varies depending on the desired melt index, so it cannot be specified in a specific manner;
Usually, it is about 0.01 to 1.0 parts by weight.

The flame retardant resin composition of the present invention comprises the component (A).

(B) JA minute, (C) m minute and ([1) JR
, minutes, and (E) r&minutes, such as carbon black, red phosphorus, organic phosphorus compounds (e.g., trialkyl phosphates, acid phosphates, dialkyl dithiophosphates, dialkyl thiophosphate chlorides, trialkyl phosphonates, phosphorus). acid triamide, phosphonium salt, etc.)
, antimony oxide (Iff) Sb2O2, phosphate (
Examples; orthomagnesium oxalate, pyromagnesium phosphate, boric acid, potassium pentabolate, etc.), barium salts (e.g.
barium carbonate, barium sulfate, barium chromate, barium oxalate, etc.), zirconium compounds (e.g., zirconium chloride, zirconium bromide, zirconium iodide, etc.)
It may contain a flame retardant improver such as.

These various flame retardancy improvers may be used alone or in combination of two or more.

When using the above component (E), the blending ratio is the same as the above (A).
Component (E) is usually added in an amount of 0.m to a total of 100 parts by weight of component (B), component (C), and component (D).
5 to 20 parts by weight, preferably 1 to 10 parts by weight. If this blending ratio is less than 0.5 part by weight, the desired effect of improving flame retardance may not be achieved sufficiently. On the other hand, if it exceeds 20 parts by weight, mechanical strength and rigidity may decrease.

-Preparation method- There are no particular limitations on the method for preparing the flame-retardant resin composition of the present invention, and for example, methods conventionally used in the preparation of glass fiber-reinforced polyolefin resin compositions can be used.

For example, a predetermined amount of each component may be mixed in advance using a ribbon blender or
It can be prepared by pre-blending using a mold blender or the like and then melt-kneading using a mixer at a temperature usually in the range of 180 to 250°C. Of course, the preparation method is not limited to these, and the order of addition and mixing of each component during mixing and melt mixing can be arbitrarily selected. Among them, after pre-blending each component other than the glass fiber in the same manner as above,
It is preferable to prepare by supplying the glass fibers to a mixer, feeding the glass fibers from the middle of the mixer, and melting and kneading them in the same manner as described above.

Examples of the mixing machine include screw type extruders such as single screw extruders and multi-screw extruders, elastic extruders, hydrodynamic extruders, ram type continuous extruders, gear type extruders, etc. Among these, screw extruders and twin-screw extruders are preferred, and two-wheel extruders are particularly preferred.

Molding methods for producing molded articles from the flame-retardant resin composition of the present invention include, for example, injection molding, extrusion molding,
Blow molding method, compression molding method, lamination molding method, roll processing method,
Various forming methods such as a stretching method and a stamping method can be employed.

The flame-retardant resin composition of the present invention can be suitably used in various applications such as, for example, a molding material for automobile parts and a molding material for electronic device parts.

[Example] Next, Examples and Comparative Examples of the present invention will be shown to further specifically explain the present invention.

(Example 1) 40 parts by weight of ethylene-propylene block copolymer (ethylene unit content 5% by weight, M I = 8 g/10 min), 30 parts by weight of fibrous magnesium hydroxide, and acid-modified polypropylene (maleic anhydride). Additional amount 5!i amount%)
After blending 2 parts by weight using a ■ type blender,
It was supplied to the hopper supply port of a two-shaft mixed wire fi (manufactured by Toshiba Machine Co., Ltd.; "Cho EM-35BJ") using a quantitative feeder.

Next, the temperature of the mixed wire was set to 200° C., and the rotor rotational speed was set to 300 rpm for kneading.

E-glass fibers treated with aminosilane after the resin is melted! 30 parts by weight (average diameter: 10mm, cut length: 3m5) were fed from a side feeder provided in a twin-screw kneader using a quantitative feeder, and melted and mixed to obtain pellets.

The blending ratio of each component used in the production of these pellets is determined in the first step.
Shown in the table.

Next, the obtained pellets were dried for 3 hours at a temperature of 110°C, and test pieces were made using an injection molding machine, and the oxygen index (01), flexural strength, flexural modulus, and isot Impact strength (no, with chi), surface appearance, and melt index (Ml) were evaluated.

The results are shown in Table 2.

The evaluation methods for each item are as follows.

OI: According to JIS X7201 Nipm bending strength, flexural modulus, Izot impact strength according to JIS X7203; Surface appearance according to JIS X7111, 140
A flat plate of 1 x 140 x 3 layers was prepared and its appearance was visually observed.

M I; Compliant with JIS X7210 (temperature 230℃
, load 2teog) (this page, below margin) (Examples 2 to 6. Comparative Examples 1 to 5) In Example 1, the types of polypropylene shown in Table 1 were used, and polypropylene and glass fiber were used. ,m! a-form magnesium hydroxide and/or fibrous xonotrite, acid-modified polyolefin, and in Examples 3 to 6 and Comparative Examples 3 and 5, each component of organic peroxide (dicumyl peroxide),
Pellet pellets were prepared in the same manner as in Example 1 except that the amounts shown in Table 1 were used, and test pieces made from the pellets were evaluated.

The results are shown in Table 2.

(Evaluation) (1) Comparing the results of Example 1 with the results of Comparative Example 1 and Comparative Example 2, it is found that Example 1 has improved flame retardancy, 1 bending strength, 1 bending modulus, and impact It can be seen that the strength has been significantly improved.

(2) Furthermore, even if the results of Example 2 and Comparative Example 3 are compared, the same thing as in (1) above can be said. It is clear that it has excellent effects as a non-halogenated flame retardant.

(3) Comparing the results of Example 1 and Example 3, it is found that in the resin composition of the present invention, when an ethylene homopolymer having a melt index of 8 or more is used as the polypropylene component (A), It can be seen that the surface appearance is particularly good.

(4) Comparing the results of Example 4 and Comparative Example 4, it is found that in Comparative Example 4, which did not use the acid-modified polyolefin as component (D), the bending strength, bending elastic modulus, and impact strength were significantly improved. It can be seen that it is decreasing. Furthermore, from the results of Comparative Example 4, it can be seen that when the melt index is small, the appearance deteriorates significantly.

(5) From the results of Examples 1 to 6 and Comparative Example 5, the content of each component is outside the range of the present invention.

It can be seen that flame retardancy is significantly reduced.

[Effects of the Invention] According to the present invention, since polypropylene, glass fiber, fibrous magnesium hydroxide and/or fibrous xonotlite, and acid-modified polyolefin are blended in a specific ratio, halogen gas is not produced during combustion. It has excellent flame retardancy, moldability, and high mechanical strength, and can be suitably used in various applications such as automobile parts molding materials and electronic device parts molding materials. An industrially useful flame-retardant resin composition can be provided.

Claims (1)

[Claims] (1) (A) 20-60% by weight of polypropylene, (B)
5 to 40% by weight of glass fiber, and (C) 15 to 40% of fibrous magnesium hydroxide and/or fibrous xonotlite.
For 100 parts by weight of a composition containing 60% by weight,
(D) A flame-retardant resin composition comprising 0.1 to 10 parts by weight of acid-modified polyolefin.