JP2839993B2 - Non-halogen flame retardant resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flame-retardant resin composition,
Particularly, the present invention relates to a non-halogen flame-retardant resin composition which does not generate toxic gas at the time of combustion and can prevent the generation of flame-burnt drippings.

[0002]

2. Description of the Related Art Conventionally, thermoplastic resins have been made flame-retardant by using halogen-based flame retardants, phosphorus-based flame retardants or antimony trioxide alone or in combination. It is known that when a halogen-based flame retardant and a phosphorus-based flame retardant are combined, the flame retardancy is synergistically improved.

However, when a halogen-based flame retardant or antimony trioxide is used, highly toxic gases such as hydrogen halide and antimony halide are generated during combustion. On the other hand, as many household electrical appliances using flame-retardant resins have become widespread in ordinary households, recently, highly safe flame-retardant resins that exhibit flame retardancy and do not generate toxic gas have been required.

For this reason, phosphorus-based flame retardants have recently attracted attention. However, when a phosphorus-based flame retardant is used alone, dripping of flame-burning particles occurs. As such, an effective anti-drip agent has been required. Under such circumstances, the pursuit of non-halogen flame retardancy has been actively studied, and the study of flame retardancy using the silicone resin of the present invention also meets such a demand.

That is, since silicone is a compound having extremely low toxicity that does not generate toxic gas upon combustion, for example, the surface of a metal hydroxide is treated with a silane coupling agent to increase the heat resistance of the flame retardant. (Japanese Unexamined Patent Publication No. 1-1)
No. 08235), and those which achieve non-halogenation by using a crosslinkable silicone oil and a silicone resin called a so-called MQ resin (Japanese Patent Publication No. Hei.
No.-48947), and those using a phosphorus-based flame retardant in combination have also been reported (JP-A-64-14277).

[0006]

However, even these flame retardants have a poor effect on styrene-based resins having a high melt viscosity, and in particular, it is possible to prevent the generation of flame-burned drippings during combustion. There was a disadvantage that there was no. Thus, the present inventors have studied various silicone compounds and have found that when a silicone-modified EPDM rubber is combined with a phosphorus-based flame retardant and a metal hydroxide, it is effective in preventing flame burn-down. Heading, the present invention has been completed.

Accordingly, a first object of the present invention is to provide a non-halogen flame-retardant resin composition which has high flame retardancy, does not generate toxic gas during combustion, and is excellent in safety. It is in. A second object of the present invention is to provide a flame-retardant resin composition that does not generate flame-burned drops during combustion.

[0008]

The above objects of the present invention are at least based on 100 parts by weight of a thermoplastic resin .
100 parts by weight of polyolefin synthetic rubber, organopoly
10 to 90 parts by weight of siloxane, crosslinking agent and reinforcing property
A crosslinked silicone-modified polyolefin-based synthetic rubber comprising a filler : 1-50 parts by weight, a phosphate ester: 1-50 parts by weight, and a metal hydroxide: 0-200 parts by weight. Achieved by a non-halogen flame retardant resin composition.

The thermoplastic resin used in the present invention can be appropriately selected from known ones, and is usually polyethylene resin (PE), polypropylene resin (PP), polystyrene resin (PS), Impact polystyrene (HIPS), polycarbonate resin (PC),
Suitable resins include polyvinyl chloride resin (PVC), acrylonitrile / butadiene / styrene copolymer resin (ABS), and acrylonitrile / styrene copolymer resin (AS).

The silicone-modified polyolefin-based synthetic rubber of the present invention has a network structure (IP) in which synthetic rubber, which is essentially an organic polymer, polysiloxane, which is an inorganic polymer, and silica, which is an inorganic filler, are bonded.
N structure). This rubber has good compatibility with other polyolefin resins and inorganic fillers,
Since it has an IPN structure, it has the property of preventing the generation of drippings during flame burning during combustion.

In the present invention, the crosslinked silicone-modified polyolefin-based synthetic rubber is added in an amount of 1 to 50 parts by weight, preferably 10 to 30 parts by weight, based on 100 parts by weight of the thermoplastic resin. Addition of 1 part or less cannot prevent the generation of flame-burnt drippings, which is the object of the present invention, and addition of 50 parts or more is not suitable because the strength of the resin is significantly impaired. The crosslinked silicone-modified polyolefin-based synthetic rubber is 100 parts by weight of a polyolefin-based synthetic rubber, and 10 to 90 parts by weight of an organopolysiloxane.
Further, a crosslinking agent and a reinforcing filler are added and crosslinked ,
An IPN structure is formed.

The synthetic rubber used is ethylene-
Propylene copolymer (EPR) and ethylene-propylene-diene copolymer (EPDM) are particularly suitable, and in addition, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer And acrylonitrile-butadiene copolymer.

As the organopolysiloxane, general dimethylpolysiloxane, phenylmethylpolysiloxane, methylvinylpolysiloxane, or organopolysiloxane containing a silanol group is used.
In particular, it is desirable to have a crosslinking point such as a vinyl group or a hydrolyzable group. The viscosity of these organopolysiloxanes is not particularly limited, but generally, those having a high viscosity having an average degree of polymerization of about 8,000 are used.

In the present invention, it is preferable to add an organosilane having a polysulfide structure and a hydrolyzable group such as a hydroxyl group or an alkoxy group in the molecule to the polyolefin synthetic rubber and the polysiloxane. The added organosilane crosslinks with the synthetic rubber and the organopolysiloxane, and further crosslinks with silica as a reinforcing filler to form a network structure.

By introducing such an organosilane having a mercapto group, in addition to peroxide vulcanization, vulcanization with sulfur, sulfur-based compounds, and metal oxides, which was impossible with conventional vinyl functional groups, can be performed. It becomes possible. Further, by using an organosilane having a hydrolyzable group such as a hydroxyl group or an alkoxy group, the surface of the active silica is modified, and the adverse effect of the silanol acidic group on the vulcanization characteristics and physical properties is removed.

The amount of the organosilane as the crosslinking agent is 1-10 parts by weight based on 100 parts by weight of the synthetic rubber. The silicone-modified polyolefin-based synthetic rubber used in the present invention has a fourth component of 20 to 100 parts by weight based on 100 parts by weight of the synthetic rubber in order to reinforce its mechanical strength.
It is preferred that silica be contained in an amount of 50 to 100 parts by weight, particularly 50 to 100 parts by weight.

When the silicone-modified polyolefin-based synthetic rubber contains an organosilane as a cross-linking agent, sulfur vulcanization is possible in addition to organic peroxide vulcanization. However, it is particularly preferred to vulcanize using an organic peroxide. Preferred organic peroxides are t-butylcumyl peroxide, dicumyl peroxide and 1,1-bis (t-butylperoxy) 3,3,3.
5-trimethylcyclohexane.

These organic peroxides are 40-70% by weight.
Is commercially available as a solution having a concentration of 0.1% by weight, but in the present invention, it is preferable to add this solution in an amount of 0.1 to 10 parts by weight, particularly 2.5 to 5 parts by weight, as an organic peroxide. Usually, it is preferable to add 0.4 to 7 parts by weight as a vulcanizing agent. Further, a vulcanization aid such as triacryl isocyanurate (TAIC) and trimethylolpropane trimethacrylate (TMP) can be added. The addition of these vulcanization aids improves the vulcanization properties and the modulus of the silicone-modified polyolefin-based synthetic rubber.

The silicone-modified polyolefin-based synthetic rubber preferably contains the above components as essential components. However, various stabilizers such as an ultraviolet absorber and an antioxidant may be further added. It is also possible to add a flame retardant beforehand. For example, decabromodiphenyl ether or antimony oxide as a halogen-based flame retardant, or a phosphoric ester as a phosphorus-based flame retardant may be added.

In the present invention, the mixture of the thermoplastic resin and the silicone-modified polyolefin-based synthetic rubber is
Further, a phosphorus-based flame retardant is added to achieve high flame retardancy. As the phosphorus-based flame retardant, a general phosphate ester is used. Among these phosphate esters, particularly preferred are, for example, triphenyl phosphate (TP
P), tricresyl phosphate (TCP), cresyl diphenyl phosphate (CPP), polyphosphate and the like.

In the present invention, a special phosphorus-based flame retardant such as ammonium polyphosphate can be used.
Phosphorus-based flame retardant is added to 100 parts by weight of the thermoplastic resin.
$ 50 parts by weight, preferably 10-30 parts by weight are added. When the amount is less than 1 part by weight, the flame retardant effect is low, and when the amount is more than 50 parts by weight, the strength of the resin is reduced and the appearance of the molded resin may be impaired.

In the present invention, in order to further enhance the flame retardancy, an inorganic flame retardant is used in addition to the phosphorus flame retardant. The inorganic flame retardant used in the present invention is generally used because of its non-toxicity, low smoke emission and the like, and a metal hydroxide is particularly preferable. Preferred metal hydroxides include aluminum trihydrate and magnesium dihydrate. Although the flame retardancy is slightly reduced, calcium aluminate and the like can be used. If use is permitted, it is natural that antimony trioxide or the like can be used as appropriate.

When metal hydroxides are used, they may absorb moisture in the air and impair the insulation of the resin. Therefore, when water-resistant insulation is required, it is preferable to use a metal hydroxide that has been subjected to a silane treatment or a treatment with a higher fatty acid in advance. These metal hydroxides are added in an amount of 0 to 200 parts by weight based on 100 parts by weight of the thermoplastic resin, but are preferably added in an amount of 10 parts by weight or more, particularly preferably 30 to 100 parts by weight.
If it is less than 10 parts by weight, the flame retardant effect is low, and if it is more than 200 parts by weight, the resin strength is significantly impaired.

In kneading the above flame retardant into the resin, it is necessary to pay attention to the temperature of the resin. That is, in the case of a phosphorus-based flame retardant, the decomposition temperature is determined depending on the compound, and a low-molecular-weight phosphoric acid ester may be 200 ° C. or lower in some cases. Even when aluminum trihydrate is used as the inorganic flame retardant, it is necessary to knead at 200 ° C. or lower in order to increase the flame retardant effect.

These flame retardants may be added and kneaded sequentially from a hopper. There is no significant difference in the order of addition during kneading, but from the viewpoint of handling the resin at as low a temperature as possible,
It may be good to add a phosphorus-based flame retardant having a plasticizing effect first. Alternatively, all the flame retardants may be mixed in advance into a paste and then added to the resin.

In formulating a flame-retardant formulation using the silicone-modified polyolefin-based synthetic rubber of the present invention, in order to reduce the amount of the above-mentioned flame retardant, for example, a flame retardant such as red phosphorus, carbon black, titanium oxide or platinum is used. Add an auxiliary agent, or various stabilizers such as antioxidants, ultraviolet absorbers, antioxidants and the like that have been conventionally added to the resin,
Reinforcing fillers and the like can be appropriately added.

[0027]

The flame-retardant resin of the present invention does not generate toxic gas even during combustion, and has good drip prevention performance. Therefore, it has heretofore been considered difficult with phosphorus-based flame retardants. Drip can be prevented even for polystyrene that has been produced.

[0028]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

Embodiment 1 EPDM rubber (EPDM / EP
T3045: trade name, manufactured by Mitsui Petrochemical Co., Ltd.) 70 parts of methylvinylpolysiloxane (vinyl group: 0.5 mol%) having a polymerization degree of 8,000 and having a hydroxyl group-terminated terminal
0 parts, 5 parts of silicone oil containing silanol groups at both terminals,
Trimethoxysilane 2 having a tetrasulfide structure
Parts, precipitated silica having a specific surface area of 230 m ² / g (Nipsil VN ³ : trade name, manufactured by Nippon Silica Co., Ltd.), 10 parts of active zinc white and 5 parts of an antioxidant, and kneaded with a two-roll mill. Thereafter, 3 parts of dicumyl peroxide was added, and primary vulcanization was performed at 170 ° C. for 10 minutes, and secondary vulcanization was performed at 150 ° C. for 2 hours.

The obtained silicone-modified EPDM rubber 10
Parts to 100 parts of standard grade polystyrene,
Further, 30 parts of tricresyl phosphate (TCP) and 100 parts of aluminum hydroxide were added, and the mixture was melt-kneaded at 170 ° C and injection-molded at a nozzle temperature of 185 ° C.
This molded product was cut into a size of 127 mm x 12.7 mm x 3 mm, and the flame retardancy was evaluated by a vertical combustion test method according to UL standards. The results are as shown in Table 1.

The determination was made according to the following V rating of UL-94 (combustion test for classification of substances according to the notice of the underwriters laboratory (Bulletin)). V-0: The maximum burning time after removing the ignition flame is within 10 seconds, the average flaming combustion and / or non-flaming combustion must not exceed 5 seconds, and all test pieces Shall not drip particles that ignite absorbent cotton.

V-1: The maximum combustion time after removing the ignition flame is within 30 seconds, the average flaming combustion and / or non-flaming combustion must not exceed 25 seconds, and all The test shall not drop particles which ignite the cotton wool. V-2: The maximum burning time after removing the ignition flame is within 30 seconds, the average flaming combustion and / or non-flaming combustion must not exceed 25 seconds, and at least one test Pieces may drip particles that ignite absorbent cotton.

Embodiment 2 FIG. EPDM rubber (EPDM / EP
43 [trade name of Nippon EP Rubber Co., Ltd.] in 95 parts, MDQ (M unit, D unit and Q unit)
Silicone having a vinyl group content of 3 mol%, wherein the ratio of the Q unit to the total amount of the M unit and the D unit (MD / Q) is 0.7 (molar ratio). Parts, 95 parts of magnesium hydroxide (product # 200 manufactured by Kamishima Chemical Industry Co., Ltd.), 4 parts of silica, Al ₂ O ₃ Si
O ₂ · 2H ₂ O 48 parts, 1 part trimethoxysilane having tetrasulfide structures, after kneaded in a two-roll by adding 2 parts of antioxidant and carbon 1 part, by addition of 3 parts of dicumyl peroxide The primary vulcanization was performed at 170 ° C. for 10 minutes, and the secondary vulcanization was further performed at 150 ° C. for 2 hours.

The obtained silicone-modified EPDM rubber 10
Parts to 100 parts of standard grade polystyrene,
Further, 20 parts of tricresyl phosphate (TCP) and 100 parts of magnesium hydroxide were added, and the mixture was melt-kneaded at 170 ° C. and injection-molded at a nozzle temperature of 185 ° C.
This molded product was cut into a size of 127 mm x 12.7 mm x 3 mm, and the flame retardancy was evaluated by a vertical combustion test method according to UL standards. The results are as shown in Table 1.

Comparative Example 1 Standard grade polystyrene 1
30 parts of tricresyl phosphate (TCP) and 100 parts of aluminum hydroxide were added to 00 parts, melt-kneaded at 170 ° C, and injection-molded at a nozzle temperature of 185 ° C. This molded product was cut into a size of 127 mm x 12.7 mm x 3 mm, and the flame retardancy was evaluated by a vertical combustion test method according to UL standards. The results are as shown in Table 1.

Comparative Example 2 Standard grade polystyrene 1
To 00 parts, 30 parts of TCP, 100 parts of aluminum hydroxide and 10 parts of silicone oil (viscosity 10,000 cs.) Were added, and the mixture was melt-kneaded at 170 ° C.
Injection molding was performed at ℃. This molded product is 127 mm × 12.
The test piece was cut into a size of 7 mm × 3 mm, and the flame retardancy was evaluated by a vertical combustion test method according to UL standards. The results are as shown in Table 1.

[0037]

[Table 1]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI (C08L 101/00 23:02 83:10) (C08L 101/00 23:26)

Claims (2)

(57) [Claims] (1) at least 100 parts by weight of a polyolefin-based synthetic rubber with respect to 100 parts by weight of a thermoplastic resin ;
10 to 90 parts by weight of an organopolysiloxane, and a crosslinking agent
And 1-50 parts by weight of a crosslinked silicone-modified polyolefin-based synthetic rubber comprising a reinforcing filler, 1-50 parts by weight of a phosphoric ester, and 0-200 parts by weight of a metal hydroxide. Non-halogen flame-retardant resin composition. 2. The flame-retardant resin composition according to claim 1, wherein the cross-linked silicone-modified polyolefin-based synthetic rubber compounded in the flame-retardant resin composition comprises: 100 parts by weight of an EPDM polymer; -90 parts by weight, made by crosslinking an organosilane 1-10 parts by weight with hydrolyzable groups with polysulfide structure, 20-100% by weight reinforcing silica filler, and vulcanizing agent 0.4 to 7 parts by weight A non-halogen flame-retardant resin composition, characterized in that: