JP2002003728A - Flame-retardant resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonhalogen rubber modified styrene based resin composi tion excellent in heat resistance and having a high flame-retardant property. SOLUTION: This flame-retardant resin composition comprises (A) a resin component (component A) mainly comprising an organic polymer especially styrene based resin and (B) an organophosphorus compound (component B) including at least 30 wt.% of a specific cyclic organophosphorus compound and including 1-70 pts.wt. of the component B per 100 pts.wt. of the component A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a resin composition having excellent heat resistance and high flame retardancy.

[0002]

2. Description of the Related Art Organic polymers, such as thermoplastic resins such as styrene resins, have excellent impact resistance and excellent moldability.
It is used in various fields, such as home appliance parts and automobile parts. However, the use of these organic polymers is limited due to their flammability. As a method for flame retarding organic polymers, particularly styrene resins, it is known to add halogen-based, phosphorus-based, or inorganic flame retardants, and the flame retardation has been achieved to some extent. However, in order to enhance product safety, regulations on flame-retardant tests for office automation equipment and molded products of home electric appliances have been stricter year after year based on the subject 94 of the United States underwriters laboratory (UL). Therefore, higher flame retardancy is required.

Heretofore, as a method for improving the flame retardancy of a styrene resin, for example, a resin composition comprising a styrene resin, a nitrogen compound such as melamine, a polyol and an organic phosphate (JP-A-4-117442), A self-extinguishing self-extinguishing styrene resin composition comprising a rubber-modified styrene resin having a specific average rubber particle diameter and a halogen-based flame retardant (JP-B-6-43542) is known. However, the resin compositions disclosed in these publications have a problem that flame retardancy is not sufficient and their use range is limited.

Further, in recent years, it has been reported that an organic compound containing halogen has an adverse effect on the environment, and non-halogenation has been actively promoted mainly in Europe. Demand for non-halogen flame retardants has also increased,
The development of non-halogen flame retardants for each resin has been actively carried out. However, it has been considered difficult to make halogen-free flame retardants of styrene resins because of their flammability.

As a known technique in this field, Japanese Patent Application Laid-Open No.
JP-A-176396 and JP-A-8-120152 disclose a resin composition of a specific rubber-modified styrenic resin and a phosphorus-based flame retardant. Specifically, triphenyl phosphate and its derivatives as a phosphorus-based flame retardant are disclosed. It has been shown that red phosphorus is used, and the flame-retardant self-extinguishing property of the molten dripping is exhibited. However, triphenyl phosphate and its derivatives increase the fluidity by its plasticity effect, facilitate ignition melting dropping, and exhibit flame retardancy. There is a drawback of poor sex. When red phosphorus is used, toxic phosphine gas is easily generated during extrusion molding of the resin composition, and there are problems such as difficulty in handling red phosphorus, and the obtained resin composition has a brown color peculiar to red phosphorus. However, there is a disadvantage that the range of use is limited.

JP-A-8-31278 discloses a rubber-modified styrenic resin, an organic phosphorus compound monomer and an organic phosphorus compound condensate, and silicone oil. A self-extinguishing melt-extinguishing styrene-based flame-retardant resin composition characterized by containing -100% by weight is disclosed. However, such a resin composition also has a disadvantage that heat resistance is inferior and practicality is poor.

As described above, the conventional rubber-modified styrene-based flame-retardant resin composition achieves flame retardancy, but is inferior in heat resistance, particularly for applications requiring high heat resistance such as OA equipment housings. It is difficult to use and its improvement is required.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a resin composition having excellent heat resistance and having a flame-retardant performance of an ignition melting dropping type. The present inventor has conducted intensive studies to achieve the above object, and as a result, a specific amount of an organic phosphorus compound containing a specific cyclic organic phosphorus compound is added to an organic polymer, particularly a resin mainly containing a styrene resin. As a result, it has been found that a resin composition having particularly excellent heat resistance, good impact resistance and flame retardancy can be obtained, and the present invention has been achieved.

[0009]

That is, according to the present invention, (A) a resin component (A component) comprising an organic polymer and (B) a cyclic organic phosphorus compound represented by the following general formula (1): A flame-retardant resin composition comprising an organic phosphorus compound (B component) containing at least 30% by weight, wherein the B component is 1 to 70 parts by weight with respect to 100 parts by weight of the A component.

[0010]

Embedded image

(In the formula, R ¹ and R ² may be the same or different and are each a branched aliphatic hydrocarbon group having 3 to 8 carbon atoms.)

In the present invention, the resin component of the component A is an organic polymer, and the organic polymer includes a thermoplastic resin and a thermosetting resin. As a thermoplastic resin,
Chlorinated polyethylene, polyethylene, polypropylene,
Polyesters such as polybutadiene, polystyrene, impact-resistant polystyrene, AS resin, ABS resin, polyvinyl chloride, polyphenylene ether, polymethyl methacrylate, polyamide, and polybutylene terephthalate;
Examples include polycarbonate, polyphenylene sulfide, polysulfone, polyether sulfone, polyimide, polyether ether ketone, polyarylate, polyether nitrile, polythioether sulfone, polybenzimidazole, polycarbimide, liquid crystal resin, and composite plastic. Examples of the thermosetting resin include polyurethane, phenol resin, melamine resin, urea resin, unsaturated polyester, diallyl phthalate resin and the like. The above resins may be used alone or in combination of two or more.

A preferred resin component is a resin component containing at least 50% by weight, preferably at least 60% by weight, more preferably at least 80% by weight of a styrene resin. Further, it is also preferable to use substantially only a styrene resin as the resin component.

Examples of such styrene resins include homopolymers or copolymers of styrene derivatives such as styrene, α-methylstyrene and p-methylstyrene, and the copolymers of these monomers with vinyl monomers such as acrylonitrile and methyl methacrylate. It is obtained by graft-polymerizing styrene and / or a styrene derivative, or styrene and / or a styrene derivative and another vinyl monomer to a copolymer, a diene rubber such as polybutadiene, an ethylene-propylene rubber, an acrylic rubber, or the like. Examples of such styrene resins include polystyrene, styrene / butadiene / styrene copolymer (SBS), hydrogenated styrene / butadiene / styrene copolymer (hydrogenated SBS), and hydrogenated styrene / isoprene / styrene copolymer (SEPS). ), Impact polystyrene (HIPS), acrylonitrile / styrene copolymer (AS resin), acrylonitrile / butadiene / styrene copolymer (ABS resin), methyl methacrylate / butadiene / styrene copolymer (MBS resin),
Methyl methacrylate / acrylonitrile / butadiene / styrene copolymer (MABS resin), acrylonitrile / acryl rubber / styrene copolymer (AAS resin),
Resins such as acrylonitrile / ethylene propylene rubber / styrene copolymer (AES resin), or a mixture thereof.

Among these styrene resins, rubber-modified styrene resins are preferable, and impact-resistant polystyrene is particularly preferably used.

The rubber-modified styrenic resin is a polymer in which a rubbery polymer is dispersed in a matrix mainly composed of an aromatic vinyl polymer in the form of particles. It can be obtained by adding a monomer mixture containing a vinyl monomer as an essential component and subjecting it to known bulk polymerization, bulk suspension polymerization, solution polymerization or emulsion polymerization.

Examples of the rubbery polymer include diene rubbers such as polybutadiene, poly (styrene-butadiene), and poly (acrylonitrile-butadiene); saturated rubber obtained by hydrogenating the diene rubber; isoprene rubber;
Examples include chloroprene rubber, acrylic rubber such as polybutyl acrylate, and ethylene-propylene-diene monomer terpolymer (EPDM). Diene rubber is particularly preferable.

The aromatic vinyl monomer which is an essential component in the graft copolymerizable monomer mixture to be polymerized in the presence of the rubbery polymer includes, for example, styrene, α-methylstyrene, paramethylstyrene and the like. And styrene is most preferred.

The rubbery polymer component in the rubber-modified styrenic resin is preferably 1 to 15% by weight, more preferably 2 to 10% by weight, and further preferably 2 to 8.5%.
% By weight, and the amount of the aromatic vinyl polymer component is preferably 99 to 85% by weight, more preferably 98 to 90% by weight.
And more preferably 98 to 91.5% by weight. Within this range, the balance of heat resistance, impact resistance and rigidity of the obtained resin composition is improved, and the unsaturated bond is less likely to be oxidized and the thermal stability is excellent.

The reduced viscosity η _sp / C (measured at 30 ° C. in a 0.5 g / dl toluene solution), which is a measure of the molecular weight of the rubber-modified styrenic resin, is preferably from 0.20 to 1.5.
0 dl / g, more preferably 0.45 to 1.20
dl / g, more preferably 0.60 to 1.00.
dl / g. Reduced viscosity η of rubber-modified styrenic resin
Means for satisfying the above conditions regarding _sp / C include:
Adjustment of the polymerization initiator, the polymerization temperature, the amount of the chain transfer agent and the like can be mentioned. The higher the reduced viscosity, the better the heat resistance and impact resistance.

The resin component A is particularly preferably (A-1) impact-resistant polystyrene 50 to 100.
% By weight and (A-2) a polyphenylene ether resin,
A resin component comprising 0 to 50% by weight of a resin selected from the group consisting of a polycarbonate resin, an ABS resin and a phenol resin is preferably used.

In the present invention, the organic phosphorus compound used as the component B is at least 30% by weight, preferably at least 50% by weight, more preferably at least 60% by weight of the cyclic organic phosphorus compound represented by the general formula (1). %, More preferably at least 80% by weight. Further, it is also preferable to use substantially only such a cyclic organic phosphorus compound as the organic phosphorus compound. By using a specific amount or more of such a cyclic organic phosphorus compound, a resin composition having excellent flame retardancy and heat resistance can be obtained.

In the above general formula (1), R ¹ and R ²
May be the same or different and is a branched aliphatic hydrocarbon group having 3 to 8 carbon atoms, preferably 3 to 5 carbon atoms, and a trivalent or tetravalent branched carbon atom bonded to a phosphorus atom. Aliphatic hydrocarbon groups are preferred. Specific examples of R ¹ and R ² include isopropyl, secondary butyl,
Tertiary butyl, neopentyl and the like can be mentioned, among which isopropyl and tertiary butyl are preferable, and tertiary butyl is particularly preferable.

Such a cyclic organic phosphorus compound can be obtained basically by reacting an alkylphosphonic acid dichloride with an adjacent diol skeleton. Such a reaction, for example,
It is disclosed in U.S. Pat. No. 4,174,343.
Further, it can be obtained by reacting a compound obtained by reacting phosphorus trichloride with an adjacent diol skeleton with aralkyl alcohol and performing Arbuzov transition at a high temperature. Such reactions are described, for example, in US Pat.
No. 2, specification of JP-A-54-157156 and JP-A-53-39698.

Specifically, the cyclic organophosphorus compound used in the present invention is obtained by reacting pentaerythritol with isopropylphosphonic dichloride, secondary butylphosphonic dichloride, tert-butylphosphonic dichloride, neopentylphosphonic dichloride, or the like. Gained by things. Alternatively, after reacting pentaerythritol with phosphorus trichloride, the obtained compound is reacted with an alkyl alcohol corresponding to
It is obtained by heating at 0 ° C to 200 ° C.

In the organophosphorus compound of the component B, other components than the cyclic organophosphorus compound represented by the general formula (1) include red phosphorus, triphenyl phosphate,
At least one compound selected from the group consisting of bis (nonylphenyl) phenyl phosphate, nonylphenyldiphenyl phosphate, tris (nonylphenyl) phosphate and condensed phosphate is preferably used.

With respect to 100 parts by weight of the resin component (component A), the amount of the organic phosphorus compound (component B) is 1 to 7
0 parts by weight, more preferably 2 to 55 parts by weight, still more preferably 3 to 35 parts by weight. If the amount is less than 1 part by weight, the obtained resin composition is inferior in flame retardancy and is not preferable.
If the amount is more than 70 parts by weight, the physical properties of the resin composition, particularly the impact resistance, are reduced, and the cost is disadvantageous and is not preferred.

In general, it is known that the heat resistance (the deflection temperature under load) is greatly reduced by blending an organic phosphorus compound with an organic polymer. However, the resin composition obtained according to the present invention preferably has a load deflection temperature retention (M) of at least 85%, more preferably at least 90%, from the resin component used. Within the range, it cannot be a practically significant defect, and is characterized by maintaining the inherently high heat resistance of the resin component.

Here, the load deflection temperature retention rate (M) is defined by the load deflection temperature x (° C.) of the molded product of the resin component A itself and the resin comprising the resin component A and the organic phosphorus compound B. In relation to the deflection temperature under load y (° C.) of the molded article of the composition, M = (y / x) × 100
(%). The deflection temperature under load is AS
It is measured at 1.81 MPa (18.5 kg load) using a 1/4 inch test piece according to a method based on TM-D648.

The styrene resin composition suitably used in the present invention has a value of the deflection temperature under load of preferably 65 to 85 ° C.

The resin composition of the present invention, by blending the above-mentioned organic phosphorus compound (component B), retains heat resistance substantially without containing a halogen-based flame retardant, and has a heat resistance of UL-94.
At least the standard flame retardant level V-2 is achieved.

The flame-retardant resin composition of the present invention may contain various other halogen-free flame retardants and flame retardant auxiliaries, such as metal hydroxides, radical generators such as dicumyl, and silicone oil. good. The silicone oil has a polydiorganosiloxane skeleton, and is preferably polydiphenylsiloxane, polymethylphenylsiloxane, polydimethylsiloxane, or an arbitrary copolymer or mixture thereof. Among them, polydimethylsiloxane is preferably used. Its viscosity is preferably 0.1.
The viscosity is from 8 to 5,000 centipoise (25 ° C.), more preferably from 10 to 1,000 centipoise (25 ° C.), and still more preferably from 50 to 500 centipoise (25 ° C.). The amount of the silicone oil is preferably in the range of 0.5 to 10 parts by weight based on 100 parts by weight of the resin component.

The flame-retardant resin composition of the present invention may contain various additives such as antioxidants, UV absorbers, deterioration inhibitors such as light stabilizers, lubricants, antistatic agents, mold release agents, plasticizers. Agents, reinforcing fibers such as glass fiber and carbon fiber, fillers such as talc, mica and wollastonite, and coloring agents such as pigments may be added. The amount of the additive to be used can be appropriately selected according to the type of the additive within a range that does not impair heat resistance, impact resistance, mechanical strength, and the like.

The flame-retardant resin composition of the present invention is usually prepared by preliminarily mixing the component A, the component B and, if necessary, other components with a mixer such as a V-type blender, a super mixer, a super floater or a Henschel mixer. After mixing, the premix is supplied to a kneader and melt-mixed. As the kneader, various melt mixers, for example, a kneader,
A single-screw or twin-screw extruder or the like can be used.
A method of melting at a temperature of about 250 ° C., more preferably about 170 ° C. to 220 ° C., injecting a liquid component with a side feeder, extruding, and pelletizing with a pelletizer is preferably used.

The flame-retardant resin composition of the present invention has particularly good heat resistance and is useful as a material for molding various molded articles such as office automation equipment parts, home electric appliance parts, and automobile parts. Such a molded product can be produced by a conventional method, for example, by injection molding a flame-retardant resin composition in the form of a pellet at a cylinder temperature of preferably about 160 to 220 ° C. using an injection molding machine.

[0036]

EXAMPLES The present invention will be described below with reference to examples.
The scope of the present invention is not limited to these examples. The evaluation was performed by the following method.

(1) Flame retardancy (UL-94 rating) Flame retardancy was measured using five 1/8 inch thick test pieces.
The evaluation was performed according to a vertical combustion test specified in UL-94 of the US UL standard as an evaluation scale of flame retardancy. In all the test pieces, the flame after removing the flame was burned within 30 seconds, and the fire was dropped and extinguished was V-2.

(2) Reduced viscosity (η _sp / C) Methyl ethyl ketone 18 was added to 1 g of the rubber-modified styrene resin.
and a mixed solvent of methanol and 2 ml of methanol.
Shake for 5 hours and centrifuge for 30 minutes at 4000 rpm at 5 ° C. The supernatant was taken out, and the resin component was precipitated with methanol and then dried. 0.1 g of the resin thus obtained was dissolved in toluene to form a 0.5 g / dl solution, and 10 ml of this solution was placed in an Ostwald viscometer having a capillary diameter of about 0.3 mm. , The number of falling t ₁ was measured. On the other hand, the number of seconds t ₀ flowing down of the toluene was measured with the same viscometer, and calculated by the following equation. At this time, the number of seconds t ₀ during which the toluene flows is about 240 seconds. η _sp / C = (t ₁ / t ₀ −1) / C (C: polymer concentration g / dl)

(3) Amount of rubbery polymer component in rubber-modified styrenic resin Nuclear magnetic resonance analyzer (UNITY 300, manufactured by Varian)
The nuclear magnetic resonance of a hydrogen atom was measured by the above method, and the amount of the rubbery polymer component was calculated from the molar ratio of the styrene unit to the butadiene unit.

(4) Deflection temperature under load (HDT), retention rate of deflection temperature under load (M) The deflection temperature under load was 1.81 MPa (1) using a 1/4 inch test piece by a method based on ASTM-D648.
8.5 kg load). Further, the load deflection temperature retention rate (M) is obtained by measuring the load deflection temperature x (° C.) of the used resin component itself and the load deflection temperature y (° C.) of the resin composition, and M = (y / x) × 100. (%).

The following components were used in Examples and Comparative Examples. (A) Rubber-modified styrene resin reduced viscosity η _sp /C=0.96 dl / g, rubber component 7.9
% Of high impact polystyrene (hereinafter HIPS-1)
) Was used. Reduced viscosity η _sp /C=0.78dl
/ G, a rubber component of 4.3% by weight of impact-resistant polystyrene (hereinafter referred to as HIPS-2). (B) Organophosphorus compound A cyclic organophosphorus compound in which both R ¹ and R ² in the formula (1) are isopropyl groups (hereinafter referred to as FR-1). In the formula (1), both R ¹ and R ² are tertiary. Cyclic organic phosphorus compound having a butyl group (hereinafter referred to as FR-2) Cyclic organic phosphorus compound having a phenyl group in both R ¹ and R ² in the general formula (1) (hereinafter referred to as FR-3) Eight Chemical Industry Co., Ltd. T
PP, hereinafter referred to as TPP)

[Examples 1 to 4, Comparative Examples 1 to 5] The components shown in Tables 1 and 2 were mixed in a tumbler in the amounts (parts by weight) shown in Tables 1 and 2, and a 15 mmφ twin screw extruder was used. (Technobel Co., Ltd., KZW15) resin temperature 18
The pellet was formed at 0 ° C., and the obtained pellet was dried with a hot-air dryer at 65 ° C. for 4 hours. The dried pellets were molded at a cylinder temperature of 200 ° C. using an injection molding machine (J75Si, manufactured by Nippon Steel Corporation). Tables 1 and 2 show the results of evaluation using the molded plate.

[0043]

[Table 1]

[0044]

[Table 2]

[0045]

Industrial Applicability The present invention provides a resin composition having excellent flame retardancy and heat resistance, and this resin composition is used for various molded articles such as office automation equipment parts, home electric appliance parts, and automobile parts. It is useful as a material for molding, and its industrial effect is outstanding.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yutaka Takeya 1-2-2 Uchisaiwai-cho, Chiyoda-ku, Tokyo F-term within Teijin Chemicals Co., Ltd. 4H028 AA35 AA42 AB04 BA06 4J002 AC031 BB031 BB121 BB241 BC021 BC031 BC051 BC061 BC071 BC081 BC091 BD041 BE041 BG061 BN141 BN151 BN161 BP011 CC031 CC181 CF071 CF161 CF211 CG001 CH071 CH091 CK011 CK021 CL001 CM021 CM041 CN011 CN031 EW126 FD130 FD136 GC00 GN00

Claims (5)

[Claims] 1. A resin component (A) comprising an organic polymer (A)
Component (B)) and (B) an organic phosphorus compound (Component B) containing at least 30% by weight of a cyclic organic phosphorus compound represented by the following general formula (1).
The flame-retardant resin composition, wherein the component B is 1 to 70 parts by weight. Embedded image (In the formula, R ¹ and R ² may be the same or different and are a branched aliphatic hydrocarbon group having 3 to 8 carbon atoms.) 2. The flame-retardant resin composition according to claim 1, wherein the resin component (A component) is a resin component containing at least 50% by weight of a styrene resin. 3. The flame-retardant resin composition according to claim 1, wherein the resin component (A component) is a resin component containing at least 50% by weight of a rubber-modified styrenic resin. 4. The flame-retardant resin composition according to claim 1, wherein the resin component (A component) is a resin component containing at least 50% by weight of impact-resistant polystyrene. 5. The flame-retardant resin composition according to claim 1, wherein the deflection temperature under load (M) represented by the following formula gives at least 85%. M = (y / x) × 100 (where x represents the deflection temperature under load (° C.) of the molded product of the resin component itself, and y is the deflection temperature of the molded product of the resin composition comprising the resin component and the organic phosphorus compound. (° C).)