JP2001081278A - Red-phosphorus-containing flame-retardant resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a red-phosphorus-containing flame-retardant resin composition which has improved mechanical strengths, flame retardance, moldability, and coatability and whose degradation in strengths due to the addition of red phosphorus is prevented by compounding a rubber-reinforced styrene resin with a phenol resin and a red phosphorus flame retardant. SOLUTION: This composition is prepared by compounding 100 pts.wt. rubber- reinforced styrene resin (A) with 1-30 pts.wt. sum of a phenol resin (B) and a red phosphorus flame retardant (C) in a ratio of C/B of 1-20. Ingredient A contains a graft polymer formed by grafting a vinyl compound onto a rubbery polymer which has a wt. average particle size of 200-1,500 nm and of which at least 20 wt.% is accounted for by rubber particles having particle sizes of 320-2,000 nm. The surface graft covering ratio defined by the formula of the vinyl compound grafted onto the rubber particles is 80% or higher; and the average thickness of the vinyl compound grafted onto the particle surface is 5-25 nm. In the formula, S is the surface area of the rubbery polymer; and (s) is the surface area of the vinyl compound covering the surface of the rubbery polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition having excellent processing fluidity and mechanical strength and excellent flame retardancy.

[0002]

2. Description of the Related Art Styrene rubber reinforced resins typified by ABS resin and HIPS are widely used as housings for OA equipment and home electric appliances because of their excellent mechanical strength and moldability. In such applications, in order to improve safety, the resin used for the housing is often required to have flame retardancy. Also, with the advent of a new genre of OA devices called mobile OA devices, it has become important to devise weight reduction and design to enhance the portability of these devices.
In terms of weight reduction, the housing tends to be thinner, and flammability, mechanical strength, and moldability in thin walls are important issues. In terms of design, secondary workability such as painting and plating of the housing is an important issue. Furthermore, with the rapid spread of OA equipment to homes, reduction of the burden on the environment at the time of disposal, which has not been required conventionally, is becoming an important issue. The flame retardant technology of styrene rubber reinforced resin is generally flame retardant using the synergistic effect of halogen flame retardant and antimony trioxide. However, halogen flame retardant is required to reduce environmental load. There is a demand for flame retardancy that does not use any.

[0003] As a method of not using a halogen-based flame retardant in the flame retardation of a styrene-based rubber-reinforced resin, Japanese Unexamined Patent Publication No.
JP-A-2-191643 discloses ABS resin and red phosphorus,
A composition comprising a thermo-crosslinkable curable resin such as melamine, a resole-based phenol resin, and polyacrylonitrile is disclosed, and JP-A-4-25543 discloses HIP.
There is a disclosure of a composition comprising an S resin and red phosphorus, an organic nitrogen compound and / or a phenol resin. However, these compositions have insufficient processing fluidity and mechanical strength. JP-A-10-298395 discloses a composition comprising a styrene-based rubber-reinforced resin, a polyester resin, a polyamide resin, and a phosphorus-based flame retardant.

However, in this composition, the mechanical strength, the occurrence of peeling of the molded product, and the strength at the weld portion are insufficient due to insufficient compatibility between the polyamide resin and the polyester resin and the styrene resin. . JP-A-7-3
Japanese Patent No. 3990 discloses a composition comprising an oxygen-containing resin, red phosphorus, and a metal hydroxide as a thermoplastic resin.
Such a composition has a good balance of flame retardancy and tensile strength when it is relatively thick, but is insufficient in impact resistance and flame retardancy when it is as thin as about 1/12 inch. JP-A-8-1
No. 76450 discloses a composition comprising a polyolefin resin, a polystyrene resin, or a polyphenylene ether resin and a specific elastomer, a flame retardant auxiliary such as red phosphorus and a phenol resin. Insufficient workability, peeling of molded products, and flame retardancy with thin walls. JP-A-6-25506 and JP-A-6-157866 propose flame retardancy by a synergistic effect of a phosphorus compound and a phenol novolak resin, but the flame retardancy is insufficient in a flame retardancy test of UL94 standard. Met. Japanese Patent Application Laid-Open No. 9-87337 discloses a rubber reinforced resin composition and a flame retardant composition having a specific coverage, but when red phosphorus is used as the flame retardant, the strength is insufficient. there were. Obtaining a flame-retardant resin composition of a rubber-reinforced resin using a red phosphorus-based flame retardant excellent in secondary workability balance such as mechanical strength, flame retardancy, molding workability, paintability and the like from the above conventional techniques. Was difficult.

[0005]

The above-mentioned attempts using a combination of a styrene-based rubber reinforced resin and red phosphorus and a phenol resin have been effective to some extent in terms of the development of flame retardancy, but the impact resistance and rigidity Mechanical strength, etc.
The processing fluidity and the flame retardancy balance were insufficient. This is because the mechanical strength is significantly reduced by the addition of red phosphorus. The problem to be solved by the present invention is to control the strength reduction due to the addition of red phosphorus, to achieve an excellent balance of mechanical strength, flame retardancy, and moldability, and to apply one of the features of styrene rubber reinforced resin. An object of the present invention is to obtain a flame-retardant rubber-reinforced resin using a red phosphorus-based flame retardant having an excellent balance of secondary workability such as heat resistance.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on solving the above-mentioned problems, and as a result, have disclosed Japanese Patent Laid-Open No. 61-291.
In the flame retardation of ABS resin by red phosphorus, phenol resin and melamine disclosed in Japanese Patent No. 643, in order to obtain a composition excellent in balance between mechanical strength, flame retardancy and moldability, a specific range is required. In a rubber-reinforced resin containing a rubber-like polymer having a particle diameter ratio of at least a certain value, the ratio of the rubber-reinforced resin composition and the ratio of red phosphorus and a phenol resin to the rubber-reinforced resin composition in which the surface graft coverage of the graft copolymer is increased is within a specific range. We found that we needed to make adjustments and arrived at the present invention. According to the present inventors, it is difficult to increase the surface graft coverage of the rubber-reinforced resin containing a rubber-like polymer in which the ratio of the particle size in a specific range is equal to or more than a certain value. Maintain the properties of styrene rubber reinforced resin for the first time by combining a rubber reinforced resin composition with a rubber graft polymer containing particles in the range of Thus, a composition excellent in balance between mechanical strength, flame retardancy, and moldability can be obtained.

That is, the present invention relates to a composition comprising a styrene rubber reinforced resin (A), a phenol resin (B) and a red phosphorus flame retardant (C), based on 100 parts by weight of the styrene rubber reinforced resin (A). Phenol resin (B) and red phosphorus flame retardant (C) in a total amount of 1 to 30 parts by weight, and red phosphorus flame retardant (C) / phenol resin (B)
In the flame-retardant resin composition having a compounding amount of 1 to 20,
Styrene rubber reinforced resin (A) is 320-2000n
a rubber polymer having a weight-average particle diameter of 200 to 1500 nm in which the ratio of rubber particles of m is not less than 20 wt%, and a graft polymer obtained by graft copolymerizing a vinyl compound with the rubber polymer. The surface graft coverage defined by the following formula (a) of the vinyl compound is 80% or more, and the average thickness of the vinyl compound graft-polymerized on the rubber particle surface is 5 to 25 nm. Flame-retardant resin composition. Surface graft coverage (%) = (s / S) × 100 (a) (where, S is the surface area of the rubbery polymer, and s is the surface area of the vinyl compound grafted and coated on the rubbery polymer surface. ).

[0008] The surface graft coverage in the present invention is:
When S is the surface area of the rubber-like polymer, and s is the surface area of the vinyl compound coated by grafting the rubber-like polymer surface, it is defined by the following formula (A). In summary, it is a measure of how much vinyl compound is grafted and coated on the surface of the rubbery polymer dispersed in the rubber-reinforced thermoplastic resin composition. Surface graft coverage (%) = (s / S) × 100 (a) The surface graft coverage (%) is, as described later, specifically, a graft polymer dispersed in a rubber-reinforced thermoplastic resin composition. Can be obtained by analyzing and measuring a photograph obtained by observing an ultrathin section with an electron microscope and taking a photograph. FIG. 1 is a schematic diagram of this electron micrograph. In the figure, the black portion is a rubbery polymer, and the hatched portion is a graft component of a vinyl compound. A1 to an are the circumferential length of the grafted portion of the vinyl compound on the rubbery polymer, and b1 to bn are the circumferential length of the portion where the vinyl compound is not grafted on the rubbery polymer. , C1 to cn indicate the cross-sectional area of the graft portion of the vinyl compound.

In FIG. 1, a1-an and b1-bn
Are measured, and R = (a1 + a2 +...
・ + An-1 + an) + (b1 + b2 +... + Bn
-1 + bn), r = (a1 + a2 +... + An-1)
+ An), R is the length corresponding to the surface area of the above-mentioned S = rubber-like polymer, and r is the length corresponding to the surface area of the above-mentioned vinyl compound grafted and coated on the surface of the rubber-like polymer. It can be determined as the surface graft coverage by the following equation (b). That is, surface graft coverage (%) = (r / R) × 100 (b). In the present invention, the surface graft coverage is 80%.
The above is necessary, and preferably 90% or more. 80
%, The flame retardancy is reduced, the impact resistance and the processing fluidity at the time of high-temperature molding are reduced, the coloring due to thermal deterioration, and more particularly, the gelation due to stagnation during extrusion and molding is undesirable.

In the present invention, the average thickness of the vinyl compound grafted on the surface of the rubber-like polymer refers to the average value of the thickness of the vinyl compound grafted on the surface of the rubber-like polymer. In FIG. 1, the area (t) corresponding to the volume of the vinyl compound grafted on the rubber-like polymer surface, that is, t = (c1 + c2 +...
+ Cn-1 + cn), and the average thickness of the vinyl compound is determined by the following formula (c). Average thickness of vinyl compound = (t / R) (c) In the present invention, the average thickness of the vinyl compound is 5 to 25 n.
m. If it is less than 5 nm, the impact resistance and the processing fluidity are reduced, and the flame retardancy is also reduced. 2
If it exceeds 5 nm, impact resistance, processing fluidity and flame retardancy will decrease.

The rubber reinforced resin (A) in the present invention contains, as a component, a graft polymer obtained by graft copolymerizing a vinyl compound with a rubbery polymer. Examples of the rubbery polymer include polybutadiene, polyisoprene, polychloroprene, butadiene-styrene copolymer, butadiene-
Conjugated diene rubbers such as acrylonitrile copolymers, acrylic rubbers such as ethylene-propylene rubber, ethyl acrylate, and butyl acrylate, and the like, preferably conjugated diene rubbers such as polybutadiene and butadiene-styrene copolymers and butadiene -An acrylonitrile copolymer. These may be used alone or in combination of two or more. The rubber-like polymer in the present invention has a rubber particle diameter of 320 to 2000 nm of 20 wt.
% Must be included. When the ratio of the particle diameter of 320 nm to 2000 nm is less than 20 wt%, the mechanical strength is reduced. It is preferably at least 25 wt%, particularly preferably at least 30 wt%.

Further, the weight average particle diameter is 200 to 1500
When the thickness is less than 200 nm, the processing fluidity and mechanical strength are reduced, and when it exceeds 1500 nm, the flame retardancy, the processing fluidity, the mechanical strength, particularly the rigidity and the flame retardancy are reduced. . The particle diameter of the rubber-like polymer can be measured on a transmission electron microscope (TEM) photograph after dyeing the rubber-like polymer with osmium tetroxide. The method for producing the rubbery polymer is not particularly limited, but a usual emulsion polymerization method can be used. Rubbery polymers obtained by such emulsion polymerization are available, for example, as polybutadiene latex, styrene-butadiene rubber latex, acrylic rubber latex, and ethylene-propylene rubber latex. The rubbery polymer used in the present invention may be used either by a method of blending two or more kinds of latexes having different particle diameters, or a method of using a rubbery polymer latex obtained by aggregating and expanding rubbery particles. good.

Further, a graft polymer latex obtained by graft-polymerizing rubbery polymer latexes having different particle diameters may be appropriately blended. In this case, 320 nm to 2000 n of the rubbery polymer according to claim 1.
The ratio of the rubbery polymer and the weight average particle diameter of m can be calculated from the blended ratio of the graft polymer latex and the particle size distribution of the rubbery polymer used for the graft polymerization. The particle size distribution refers to a histogram representing the frequency of rubber particles corresponding to a particle size within a certain range.

The vinyl compound to be graft-copolymerized to the rubbery polymer used in the present invention includes aromatic vinyl compounds such as styrene, main chain or side chain substituted styrene, vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, and acrylic acid. Methyl, ethyl acrylate, acrylates such as butyl acrylate and methacrylates of similar substituents, acrylic acid, acrylates such as methacrylic acid and N-phenylmaleimide,
A maleimide monomer such as N-methylmaleimide, a glycidyl group-containing monomer such as glycidyl methacrylate, and the like are also used. These may be used alone or in combination of two or more. Of these monomers, a combination of an aromatic vinyl compound and a vinyl cyanide compound is preferred. Particularly preferred is a combination of styrene and acrylonitrile.

The proportion of the components grafted to the rubbery polymer produced in the course of the production of the graft polymer is measured by dissolving the graft polymer produced by the polymerization reaction in acetone and separating and removing the insoluble matter with a centrifuge. can do. The component soluble in acetone is a non-grafted component of the copolymerized copolymer (non-grafted component). The value obtained by subtracting the amount of the rubbery polymer from the acetone-insoluble component is defined as the value of the graft component. You. Preferably, the proportion of the graft component is 10%.
0 parts by weight is 10 to 80 parts by weight, more preferably 20 to 60 parts by weight.

The method for producing the above graft polymer includes the following:
Although it is not particularly limited, it is an emulsion graft polymerization system in which a vinyl compound is graft-polymerized to a rubbery polymer latex produced by emulsion polymerization, and any of a continuous system, a batch system, and a semi-batch system is possible. In the present invention, a vinyl compound is used as an initiator for a rubbery polymer produced by emulsion polymerization,
An emulsification grafting method of continuously adding together with a molecular weight regulator and the like is particularly preferable. When using the emulsion grafting method,
In order to make the surface graft coverage 80% or more, the amount of the emulsifier used in the emulsion graft polymerization should be extremely small. It is particularly preferred to add it little by little. The pH at the time of polymerization may be any of alkaline, neutral and acidic conditions, but is preferably neutral. The emulsifier used for the emulsion polymerization is not particularly limited, but is generally used for the emulsion polymerization (hereinafter may be abbreviated as a non-polymerizable emulsifier), for example, rosinate, higher fatty acid salt, alkyl sulfate salt Anionic emulsifiers such as alkyl benzene sulfonate, alkyl diphenyl ether disulfonate, polyoxyethylene alkyl phenyl ether sulfate and dialkyl sulfosuccinate; and nonionic emulsifiers such as polyoxyethylene alkyl ether and polyoxyethylene alkyl phenyl ether. can give. Further, an emulsifier having one or more double bonds in the compound and capable of radical polymerization with a conjugated diene rubber, an aromatic vinyl compound, a vinyl cyanide compound and / or a (meth) acrylate compound (hereinafter referred to as polymerizable (May be abbreviated as an emulsifier). As these polymerizable emulsifiers,
Examples include a polymerizable emulsifier represented by the following formula (1).

[0017]

Embedded image

In the formula, X represents a (meth) allyl group, a (meth) acryloyl group or a (1-propenyl) vinyl group. Y is hydrogen or -SO3M (M is hydrogen, an alkali metal, an alkaline earth metal, ammonium or
Or a carboxylate represented by -CH2COOM (M is hydrogen, an alkali metal, an alkaline earth metal, ammonium, or a hydroxyalkylammonium having 1 to 4 carbon atoms) Or a phosphoric acid monoester salt represented by the following formula (1 ′).

[0019]

Embedded image

(Wherein M1 and M2 are hydrogen, alkali metal, alkaline earth metal, ammonium or C1-C2)
4, a hydroxyalkyl ammonium, M1, M
R1 is an alkyl group having 1 to 18 carbon atoms, an alkenyl group or an aralkyl group, R2 is hydrogen or an alkyl group having 1 to 18 carbon atoms,
An alkenyl group or an aralkyl group, R3 represents hydrogen or a propenyl group, A represents an alkylene group having 2 to 4 carbon atoms or a substituted alkylene group, and n represents an integer of 1 to 200. Further, specifically, compounds represented by the following formulas (2) to (6) can be used.

[0021]

Embedded image

These emulsifiers may be used alone or in combination of two or more. The content of the rubbery polymer in the rubber reinforced resin (A) is determined by impact resistance, processing fluidity, rigidity and the like, but is preferably 5 to 60% by weight, more preferably 10 to 40% by weight, More preferably, it is 15 to 25% by weight. In the present invention, since a vinyl compound is graft-polymerized to the rubbery polymer, the content of the graft polymer contained in the rubber-reinforced resin (A) is 5.5% by weight or more.

The rubber-reinforced resin (A) of the present invention may contain a component which is not grafted on the rubber-like polymer produced in the course of producing the graft polymer. The method for producing the rubber-reinforced resin (A) is not particularly limited. For example, a method for simultaneously producing a graft polymer and a non-graft-polymerized vinyl copolymer by emulsion polymerization, and a method for producing a rubber-like polymer by emulsion polymerization. A mixture of a high-graft graft polymer and a vinyl copolymer (hereinafter sometimes abbreviated as GRC) is prepared in advance and blended with a vinyl copolymer produced separately by bulk polymerization, emulsion polymerization, suspension polymerization, etc. A method for reducing the rubber content is described. The vinyl copolymer in this case is not limited to amorphous or crystalline, but is preferably the above-mentioned aromatic vinyl compound, vinyl cyanide compound, acrylate or methacrylate.

More preferably, aromatic vinyl compounds such as styrene, main chain or side chain substituted styrene, vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, and acrylate esters such as methyl acrylate, ethyl acrylate and butyl acrylate And methacrylic acid esters such as methacrylic acid esters, acrylic acid and methacrylic acid, and maleimide monomers such as N-phenylmaleimide and N-methylmaleimide; and glycidyl group-containing monomers such as glycidyl methacrylate. Particularly preferred are an aromatic vinyl compound and a vinyl cyanide compound. Most preferred is a combination of styrene and acrylonitrile, a combination of styrene and acrylonitrile and N-phenylmaleimide.

The phenolic resin (B) used in the present invention
Is generally obtained by adding and condensing phenol and aldehyde under an acid catalyst in a novolak type having a high phenol content and obtained by adding and condensing phenol and aldehyde under a basic catalyst. It is a resole system having a high content of methylol, and an insoluble and infusible phenol resin obtained by curing them. Preferred are novolak-type phenolic resins, and particularly preferred are phenol-formaldehyde novolak resins, tertiary-butylphenol-formaldehyde novolak resins, para-octylphenol-formaldehyde novolak resins, paracyanophenol-formaldehyde novolak resins, and copolymers thereof. Most preferred is a phenol formaldehyde novolak resin, with a preferred molecular weight of 300 to 10,000. These phenol resins may be used alone or in combination of two or more.

The red phosphorus-based flame retardant (C) of the present invention is a red phosphorus-based flame retardant containing red phosphorus as a component, and is a red phosphorus-based flame retardant coated on the surface with uncoated red phosphorus particles and metal hydroxide. Flame retardant, red phosphorus flame retardant surface coded with thermosetting resin, red phosphorus flame retardant surface coded with a mixture of metal hydroxide and thermosetting resin, thermosetting on metal hydroxide coating Red phosphorus-based flame retardants coated with resin, red phosphorus-based flame retardants obtained by applying electroless plating to red phosphorus, and the like are preferable. Red phosphorus-based flame retardants coated with a metal hydroxide and a thermosetting resin are preferred. It is a red phosphorus-based flame retardant in which a flame retardant and a metal hydroxide are further coated twice with a thermosetting resin. The phosphorus content in the red phosphorus-based flame retardant is preferably 80 to 99 wt%, more preferably 85 to 95 wt%.

The contents of the phenolic resin (B) and the red phosphorus-based flame retardant (C) in the present invention are such that (B) + (C) is 1 to 3 with respect to 100 parts by weight of the styrene-based rubber-reinforced resin (A).
It must be 0 parts by weight. When the amount is less than 1 part by weight, flame retardancy and heat resistance are insufficient. If it exceeds 30 parts by weight, the mechanical strength is insufficient. Preferably 5
It is 25 parts by weight, particularly preferably 10 to 20 parts by weight. The content of the phenolic resin (B) and the red phosphorus-based flame retardant (C) needs to be (C) / (B) of 1 to 20. When it is less than 1, the flame retardancy and chemical resistance are insufficient, and when it exceeds 20, the flame retardancy and mechanical strength are insufficient. It is preferably from 1.5 to 10, particularly preferably from 2 to 5.

[0028] The composition of the present invention may further contain any additives for the purpose of modification, ie, a lubricant, a silicone oil,
Lubricants such as olefin oils and low molecular weight polytetrafluoroethylene, antistatic agents, antioxidants, ultraviolet absorbers, coloring agents, titanium oxide, surface modifiers, dispersants, plasticizers, glass fibers, and carbon fibers And conventional additives such as fillers and fillers such as mica and talc, metal hydroxides such as aluminum hydroxide and magnesium hydroxide, silicone resins, anti-dripping agents such as high molecular weight polytetrafluoroethylene and the like. I can do it.

The method for producing the resin composition of the present invention is not particularly limited, but ordinary methods such as kneading with an extruder, melt blending using a Banbury mixer, a kneader, and the like, and adding other components during the polymerization of the rubber-reinforced resin are used. It can be produced by a method, a solvent blend or the like. The composition of the present invention can be used for injection molding, compression molding, sheet molding, vacuum molding and the like.

The use of the resin composition and the molded article of the present invention is not particularly limited, and examples thereof include a personal computer (PC), a portable personal computer, a facsimile, and a CR.
It is used as a housing for various OA devices such as T and televisions and household appliances, and also for mobile phones.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail based on embodiments. Parts used below are parts by weight.
The measuring method in the example of the present invention is as follows. (Surface Graft Coverage) The rubber-reinforced thermoplastic resin composition is dissolved in a solvent in which the sol component is soluble (for example, acetone in the case of ABS resin), and then centrifuged to take out a gel component. After the gel component is dispersed in acetone using an ultrasonic homogenizer, it is added to the epoxy resin-based adhesive main agent and dispersed again. After removing the acetone by vacuum drying, a curing agent for an epoxy resin adhesive is added, mixed, heated and solidified. Thereby, a graft polymer dispersed in the epoxy resin is obtained.

The obtained epoxy resin containing the graft polymer is, for example, in the case of an ABS resin, dyed with osmium tetroxide, prepared an ultrathin section with an ultramicrotome, and observed and photographed with a transmission electron microscope. Ultrathin section thickness is 60
nm. For analysis of the electron micrograph of the graft polymer, the surface graft coverage was measured using an image analyzer IP-1000 (manufactured by Asahi Kasei Corporation). Specifically, in the image obtained by separating the rubber-like polymer in the graft polymer and the vinyl compound component grafted on the surface of the rubber-like polymer, as shown in FIG.
-An and b1-bn were measured, and R =
(A1 + a2 +... + An-1 + an) + (b1 +
.. + bn-1 + bn) and r = (a1 + a2)
+ ··· + an-1 + an) and the surface graft coverage is determined by the following equation (b). The unit in the table is shown in%. Surface graft coverage (%) = (r / R) × 100 (b)

In the measurement of the surface graft coverage in the examples, only the graft polymer having a particle size of 320 nm or more was selected and subjected to the measurement. The number of measurements is 10. (Average Thickness of Vinyl Compound) The thickness of the vinyl compound grafted on the surface of the rubber-like polymer can be determined by subjecting the obtained rubber-reinforced thermoplastic resin composition to osmium tetroxide in the same manner as the above surface graft coverage. After staining and preparation of an ultrathin section with an ultramicrotome, the section was observed and photographed with a transmission electron microscope.
For analysis of the electron micrograph of the graft polymer, an image analyzer IP-1000 (manufactured by Asahi Kasei Corporation) was used.

Specifically, in the image obtained by separating the rubbery polymer in the graft polymer and the vinyl compound grafted on the surface of the rubbery polymer, the image corresponds to the surface area of the rubbery polymer in FIG. Perimeter (R), ie R =
(A1 + a2 +... + An-1 + an) + (b1 +
.. + bn-1 + bn), and then the area (t) corresponding to the volume of the vinyl compound grafted on the surface of the rubbery polymer, that is, t = (c1 + c2 + ·).
.. + Cn-1 + cn), the average thickness of the vinyl compound is determined by the following formula (c). Average thickness of vinyl compound = (t / R) (c) The number of measurement is 10. The unit in the table is described in nm. (Weight average particle diameter of rubber-like polymer) One drop of a dilute solution of the rubber-like polymer used for graft polymerization was taken on a metal mesh for transmission electron microscope measurement, and stained with osmium tetroxide or ruthenium tetroxide vapor. The stained sample was photographed with a transmission electron microscope, and the weight average particle diameter of the particles was determined using the above-mentioned image analyzer IP-1000.
The number of measurements is 500. (Physical Property Evaluation Methods) Various physical property evaluation methods are as shown below. (1) Izod impact value The pellet was molded at a molding temperature of 240 ° C and a mold temperature of 45 ° C to obtain a test piece. The test was performed on a 1/2 inch x 1/4 inch x 5/2 inch notched test piece based on ASTM-D256. The unit is kg · cm / cm. (2) Melt flow rate Measured based on JIS K7210. Measurement conditions are 220
The unit is g / 10 min at 10 ° C. under a load of 10 kg. It is an index of processing fluidity. (3) Flame retardancy UL94 standard vertical combustion test (thickness 1/8 inch, 1/1
In the test based on 2 inches), those having a flame retardancy less than V-0 and V-1 are marked with x. (4) Blow Dart The pellets are molded at a molding temperature of 240 ° C. and a mold temperature of 45 ° C. to obtain a 150 mm square plate with a thickness of 2 mm.
The total load (W) of the missile and the load of the semicircle with a missile diameter of 3/4 inch is dropped on the flat plate from the height (H), and the load (W) required to destroy 50% of the flat plate is determined. Then, the falling weight impact strength (kg · cm) is calculated from the height (H) at that time by the following equation.

Drop weight impact strength (kg · cm) = Load required for 50% destruction (W) × Drop height (H) A composition having a higher value of the drop weight impact strength can withstand the impact of a molded product. It is an index of mechanical strength. Although not correlated with the Izod impact value, the falling weight impact strength is an important strength index in terms of the practical strength of a molded product. (5) Flexural modulus Measured based on ASTM D790, unit is kg / cm
/ Cm. (6) Heat resistance In a test based on ASTM D648, the thickness of the test piece was 1 /
4 inches. The unit is ° C. (Rubber-like polymer S) (1) Rubber-like polymer latex (S-1) 320 nm to 2000 nm determined by electron micrograph
Butadiene rubber latex having a rubber particle ratio of 48% by weight. The weight average particle size was 320 nm. pH was 10.1. (2) Rubbery polymer latex (S-2) 320 nm to 2000 nm determined by electron micrograph
Butadiene rubber latex having a rubber particle ratio of 85% by weight. The weight average particle size was 360 nm. pH was 10.0. (3) Rubbery polymer latex (S-3) 320 nm to 2000 nm determined by electron micrograph
A styrene-butadiene rubber latex having a rubber particle ratio of 61% by weight. The weight average particle size is 290
nm. pH was 10.1.

(4) Rubbery polymer latex S-4 320 nm to 2000 nm determined by electron micrograph
Butadiene rubber latex having a rubber particle ratio of 11% by weight. The weight average particle size was 330 nm. pH was 10.0. (5) Rubbery polymer latex (S-5) 320 nm to 2000 nm determined by electron micrograph
Butadiene rubber latex having a rubber particle ratio of 3% by weight. The weight average particle size was 170 nm. pH was 10.1. (6) Rubbery polymer latex (S-6) S-5 based on 70 parts of solid content of rubber latex S-2
Was blended with a solid content of 30 parts. The ratio of rubber particles having a particle diameter of 320 nm to 2000 nm determined by an electron micrograph was 59% by weight. Weight average particle size is 280
nm. pH was 10.1. Table 1 shows the properties of the rubber latex used.

[0037]

[Table 1]

(Vinyl Copolymer T) (1) Vinyl Copolymer (T-1) The composition of the copolymer T-1 was determined by IR spectrum from acrylonitrile 30% by weight, styrene 70% by weight, and methyl ethyl ketone. The intrinsic viscosity (a solution in which 0.5 g of the copolymer T-1 was dissolved in 100 ml of methyl ethyl ketone, 30 ° C.) measured at 0.39 was 0.39. (2) Vinyl copolymer (T-2) The composition in the copolymer T-2 was determined by IR spectrum at 37% by weight of acrylonitrile, 63% by weight of styrene, and the intrinsic viscosity (in 100 ml of methyl ethyl ketone) measured in methyl ethyl ketone. The solution in which 0.5 g of the copolymer T-1 was dissolved, 30 ° C.) was 0.35. (3) Vinyl copolymer (T-3) 18% by weight of acrylonitrile, 50% by weight of styrene, N
-Phenylmaleimide 32% by weight terpolymer, solution viscosity (10% by weight polymer in methyl ethyl ketone solvent)
At 25 ° C.) was 6 centipoise.

(Phenol resin B) (1) Phenol resin (B-1) Novolak type phenol resin (manufactured by Mitsui Toatsu Co., Ltd.)
1000WS). (2) Phenol resin (B-2) A resole-based phenol resin (Bellpearl S-890 manufactured by Kanebo Co., Ltd.) was used. (Red phosphorus flame retardant C) (1) Red phosphorus flame retardant (C-1) Nova Excel 140 manufactured by Rin Kagaku Kogyo Co., Ltd. was used.
The phosphorus content was 92% by weight. (2) Red phosphorus flame retardant (C-2) Nova Red 120UFA manufactured by Rin Kagaku Kogyo Co., Ltd. was used. The phosphorus content was 91 wt%.

[0040]

Examples 1 to 5 and Comparative Examples 1 and 2 (Production of mixture G of graft polymer and vinyl copolymer) (Production of G-1) Rubber latex S-1 (solid content) 4
0 parts, 0.2 parts of the emulsifier represented by the formula (2), and 100 parts of ion-exchanged water were charged into a 10-liter reactor, and the gas phase was replaced with nitrogen. Then, the initial solution was heated to 70 ° C. Adjustment of pH before polymerization was performed by bubbling carbon dioxide gas in the reactor. Next, an aqueous solution 1 and a monomer mixture 2 having the following composition were continuously added to the reactor over a period of 5 hours, and polymerization was carried out in a formulation in which the amount of the emulsifier used in the initial stage of polymerization was extremely small. After completion of the addition, the temperature was maintained for 1 hour to complete the reaction. The composition of the aqueous solution 1 is as follows.

Ferrous sulfate 0.005 part Sodium formaldehyde sulfoxylate (SFS) 0.1 part Disodium ethylenediaminetetraacetate (EDTA) 0.05 part Ion exchange water 50 parts Composition of monomer mixture 2 Is as follows. Acrylonitrile 18 parts Styrene 42 parts t-Dodecyl mercaptan (t-DM) 0.8 parts Cumene hydroperoxide (CHP) 0.1 parts

An antioxidant was added to the thus obtained GRC latex, aluminum sulfate was added for coagulation, washed with water, dehydrated, and dried by heating to obtain a GRC powder. Table 2 shows the surface graft coverage of the obtained graft polymer and the average thickness of the graft. (Production of G-2 to 7) Obtained in the same manner as G-1 except that the rubber latex and composition used were changed as shown in Table 2. Table 2 shows the surface graft coverage of the obtained graft polymer and the average thickness of the graft. The polymerization conditions in Table 2 represent pH.

[0043]

[Table 2]

Each of the components prepared as described above was used in a composition (unit: parts by weight) shown in Table 3 and a cylinder temperature of 220
After kneading and granulating with a twin screw extruder set at a temperature of ° C, a test piece for measuring physical properties and a molded piece for a combustion test were obtained using an injection molding machine (cylinder temperature 240 ° C, mold temperature 45 ° C).
Table 3 shows the results of evaluation using the obtained test pieces.

[0045]

[Table 3]

Examples 1 to 5 and Comparative Examples 1 and 2 show that the rubber-like polymer in the rubber-reinforced resin (A) has a thickness of 320 nm to 2 nm.
It shows the effect of the difference in the ratio of the particles of 000 nm and the weight average particle diameter. The resin compositions of Examples 1 to 5,
The flame-retardant resin composition according to claim 1, which has an excellent balance of Izod impact value, one-shot dart and melt flow rate, and heat resistance, which are indicators of flame retardancy and mechanical strength. Since these flame-retardant resin compositions are styrene rubber-reinforced resins, they have good coatability. Comparative Examples 1-2
The flame-retardant resin composition of the present invention has a rubber-reinforced polymer (A) having a ratio of particles of 320 nm to 2000 nm and a weight average particle diameter of the rubbery polymer outside the scope of the claims. Insufficient balance. In particular, the balance between the Izod impact strength and the melt flow rate of the resin composition of Comparative Example 1 is slightly inferior to that of Example 5, but the practical strength is insufficient due to a low blow dirt.

[0047]

Examples 6-8, Comparative Examples 3-4 (Production of G-8-10) Rubber G latex and compositions were obtained in the same manner as G-1 except that the rubber latex and the composition used were changed as shown in Table 5. Table 4 shows the surface graft coverage of the obtained graft polymer and the average thickness of the graft.

[0048]

[Table 4]

Each of the components prepared as described above was used in a composition (unit: parts by weight) shown in Table 5 and a cylinder temperature of 220
After kneading and granulating with a twin screw extruder set at a temperature of ° C, a test piece for measuring physical properties and a molded piece for a combustion test were obtained using an injection molding machine (cylinder temperature 240 ° C, mold temperature 45 ° C).
Table 5 shows the results of evaluation using the obtained test pieces.

[0050]

[Table 5]

Examples 6 to 8 and Comparative Examples 3 and 4 show the effects of differences in the surface graft coverage and the average thickness of the graft polymer grafted on the rubbery polymer. The resin compositions of Examples 6 to 8 have flame retardancy, mechanical strength, processing fluidity, since the surface graft coverage of the graft polymer and the average thickness of the graft are within the range of the present invention.
It is a flame-retardant resin composition having an excellent balance. Since these flame-retardant resin compositions are styrene rubber-reinforced resins, they have good coatability. In Comparative Example 3, the balance between flame retardancy and processing fluidity was insufficient because the surface graft coverage was outside the range of the present invention. Comparative Example 4 has good flame retardancy because the average thickness of the graft is out of the range of the present invention.
The balance between impact resistance and processing fluidity is insufficient. Example 6 has a lower blow dirt value than Comparative Example 4, but is excellent in flame retardancy, rigidity, and processing fluidity balance.

[0052]

Examples 9 to 15 and Comparative Examples 5 to 9 G-6 of GRC used in Examples 1 to 5 and each component were prepared according to the compositions (units by weight) shown in Tables 6 and 7 and the cylinder temperature was reduced. After kneading and granulating with a twin-screw extruder set at 220 ° C., a test piece for measuring physical properties and a test piece for combustion test were obtained using an injection molding machine (cylinder temperature 240 ° C., mold temperature 45 ° C.). . Table 5 shows the results of evaluation using the obtained test pieces.

[0053]

[Table 6]

[0054]

[Table 7]

Examples 9 to 15 and Comparative Examples 5 to 9 show the effects of differences in the amounts and ratios of the phenolic resin (B) and the red phosphorus-based flame retardant (C). Examples 9-1
The resin composition of No. 5 comprises (B) + (C) and (C) /
Since the value of (B) is within the range of the present invention, the flame-retardant resin composition is excellent in flame retardancy, mechanical strength, and processing fluidity balance. Since these flame-retardant resin compositions are styrene rubber-reinforced resins, they have good coatability. In Comparative Examples 5 and 8, since the value of (C) / (B) was less than the range of the present invention, the flame retardancy was insufficient. Comparative Examples 6 and 9 are (C) / (B)
Value exceeds the range of the present invention, impact strength, flame retardancy,
Processing fluidity balance is insufficient. Comparative Example 7
Since the content of (B) + (C) exceeds the range of the present invention, impact strength and processing fluidity are insufficient.

[0056]

The flame-retardant resin composition of the present invention has flame-retardant properties,
Excellent processing fluidity and mechanical strength balance. This effect is exhibited by the combination of a rubber-reinforced resin, a phenol resin, and a red phosphorus-based flame retardant in a composition having a weight average particle
In a rubber-like polymer in which the ratio of rubber particles of 0 nm to 1500 nm and 320 nm to 2000 nm is 20 wt% or more,
The surface graft coverage of the graft polymer obtained by graft copolymerization of the vinyl compound is 80% or more, and the average thickness of the vinyl compound graft-polymerized on the rubbery polymer surface is 5 to 25 nm. It can be achieved by using the characteristic graft polymer as a component of the rubber-reinforced resin, and further adjusting the total addition amount and the ratio of the phenol resin and the red phosphorus-based flame retardant to specific ranges.

[Brief description of the drawings]

FIG. 1 is a diagram showing a specific analysis example for determining the surface graft coverage and the coating thickness of a vinyl compound according to the present invention.

Claims (5)

[Claims] 1. A styrene rubber reinforced resin (A), a phenol resin (B) and a red phosphorus flame retardant (C),
The total amount of the phenolic resin (B) and the red phosphorus-based flame retardant (C) is 1 to 30 parts by weight with respect to 100 parts by weight of the styrene rubber-reinforced resin (A), and the red phosphorus-based flame retardant (C)
/ Phenolic resin (B) in a flame retardant resin composition having a compounding ratio of 1 to 20;
Is 20% by weight of a rubber particle having a size of 320 to 2000 nm.
The above-mentioned rubber compound having a weight average particle diameter of 200 to 1500 nm contains a graft polymer obtained by graft copolymerizing a vinyl compound, and the vinyl compound graft-polymerized on the rubber particles has the following formula (A) And the average thickness of the vinyl compound graft-polymerized on the surface of the rubber particles is 5% or more.
A flame-retardant resin composition having a thickness of from 25 to 25 nm. Surface graft coverage (%) = (s / S) × 100 (a) (where, S is the surface area of the rubbery polymer, and s is the surface area of the vinyl compound grafted and coated on the rubbery polymer surface. ) 2. The flame-retardant resin composition according to claim 1, wherein the vinyl compound according to claim 1 contains styrene and acrylonitrile. 3. The vinyl compound according to claim 1, comprising styrene and acrylonitrile, wherein the content of the rubbery polymer in the styrene rubber reinforced resin (A) is 15 to 25.
3. The flame-retardant resin composition according to claim 1, which is in terms of weight%. 4. The phenolic resin (B) according to claim 1.
Is a novolak-type phenolic resin. 5. The phenolic resin (B) according to claim 1 is a novolak-type phenolic resin, and the compounding ratio of the red phosphorus-based flame retardant (C) / phenolic resin (B) is 2 to 5. 5. The flame-retardant resin composition according to 4.