TWI828699B - Method for producing styrene-based flame-retardant resin composition - Google Patents

Abstract

To provide a method for producing a flame-retardant resin composition excellent in thermal stability, the flame-retardant resin composition containing a styrene resin and a brominated polymer type flame retardant.

In the production of a styrene-based flame-retardant resin composition using (A) a brominated polymer type flame retardant, (B) a styrene resin, (C) a stabilizer, and (D) a liquid paraffin or epoxidized vegetable oil, at least the brominated polymer type flame retardant (A) and the liquid paraffin or epoxidized vegetable oil (D) are mixed together, and then the resulting mixture and the other components are melt-kneaded in an extruder at a resin temperature lower than 210℃.

Description

Method for manufacturing styrene-based flame-retardant resin composition

The present invention relates to a method for manufacturing a flame-retardant resin composition containing a styrene-based resin and a brominated polymer-type flame retardant.

As a flame retardant used to impart flame retardancy to styrenic resin molded articles, hexabromocyclododecane (HBCD) is generally used. HBCD has bioaccumulation properties, is toxic to aquatic organisms, and is not easily decomposed. From this point of view, Brominated polymer flame retardants are being studied as alternatives (see Patent Document 1).

In addition, as stabilizers for brominated polymer-type flame retardants, alkyl phosphites and epoxy compounds are known (see Patent Document 2).

It is used for extrusion molding. During extrusion molding, a high-concentration flame retardant masterbatch composition is used in consideration of dispersibility (see Patent Document 3).

[Prior technical literature] [Patent Document]

Patent Document 1: Japanese Patent Publication No. 2009-516019

Patent Document 2: Japanese Patent Publication No. 2012-512942

Patent Document 3: Japanese Patent Application Publication No. 2013-23508

An object of the present invention is to provide a method for producing a flame-retardant resin composition containing a styrenic resin and a brominated polymer-type flame retardant and having excellent thermal stability.

As a result of intensive research on the above-mentioned subject, the inventors found that a flame-retardant resin composition (melt) was produced using a brominated polymer flame retardant, a styrenic resin, a stabilizer, and liquid paraffin or epoxidized vegetable oil. , after mixing at least the brominated polymer type flame retardant with liquid paraffin or epoxidized vegetable oil, the extruder is used to melt and knead the mixture at a resin temperature of less than 210°C, thereby completing the present invention.

That is, the present invention is as follows.

1. A method for manufacturing a styrene-based flame-retardant resin composition, which is a method for manufacturing a styrene-based flame-retardant resin composition, characterized in that: the aforementioned styrene-based flame-retardant resin composition contains (A) bromination polymerization Physical flame retardant, (B) styrenic resin, (C) stabilizer, and (D) liquid paraffin or epoxidized vegetable oil, the bromine content is 18 mass% or more and 42 mass% or less, and at least the aforementioned ( A) The brominated polymer flame retardant is mixed with the aforementioned (D) liquid paraffin or epoxidized vegetable oil, and then melt-kneaded by an extruder at a resin temperature of less than 210°C.

2. The method for producing a styrenic flame-retardant resin composition as described in 1 above, wherein the stabilizer (C) is selected from the group consisting of antioxidants, halogen scavengers, novolac-type epoxy resins, and alkyl phosphites. At least 2 or more types.

3. The method for producing a styrenic flame-retardant resin composition as described in 1 or 2 above, wherein the amount is 100 parts by mass based on a total of 100 parts by mass of the above-mentioned (A) brominated polymer flame retardant and the above-mentioned (B) styrene-based resin. , the aforementioned (C) stabilizer system contains not less than 5 parts by mass and not more than 30 parts by mass, and the aforementioned (D) liquid paraffin or epoxidized vegetable oil system contains not less than 1 part by mass and not more than 8 parts by mass.

4. The method for producing a styrenic flame-retardant resin composition according to any one of the above 1 to 3, wherein the (A) brominated polymer flame retardant (a) contains butadiene and vinyl aromatic A copolymer in which aromatic hydrocarbons are monomer components, (b) the content of vinyl aromatic hydrocarbon monomers in the copolymer before bromination is 5 mass % or more and 90 mass % or less, (c) butadiene contains 1 , 2-butadiene, (d) the weight average molecular weight (Mw) is more than 1,000, (e) the unbrominated non-aromatic double bond content obtained by ¹ H-NMR spectroscopy is based on the copolymer before bromination The non-aromatic double bond content is less than 50% based on the basis. (f) The 5% reduction temperature obtained by thermogravimetric analysis (TGA, Thermogravimetric Analysis) is above 200°C.

5. The method for producing a styrene-based flame-retardant resin composition according to any one of 1 to 4 above, wherein the extruder is a twin-screw extruder.

6. A flame-retardant resin molded article, characterized in that it contains a styrene-based flame-retardant resin composition produced by the method for producing a styrene-based flame-retardant resin composition according to any one of 1 to 5 above. .

7. A flame-retardant resin molded article, characterized in that it contains a styrene-based flame-retardant resin composition produced by the method for producing a styrene-based flame-retardant resin composition according to any one of 1 to 5 above. , and further styrenic resins.

The extrusion manufacturing method of the styrene-based flame retardant resin composition of the present invention stabilizes the brominated polymer type flame retardant, and can produce a high-concentration thermoplastic resin composition of the brominated polymer type flame retardant, which can be supplied It is an extruded product with good appearance and therefore has great industrial utilization value.

"(A) Brominated polymer flame retardant"

(A) The brominated polymer type flame retardant used in the present invention is a commonly known one, and the one disclosed in Patent Document 1 or 2 can be used directly. It is preferred to use brominated copolymers having the following characteristics (a) to (f).

(a) A copolymer having butadiene and vinyl aromatic hydrocarbon as monomer components.

(b) The content of the vinyl aromatic hydrocarbon monomer in the copolymer before bromination is 5 mass% or more and 90 mass% or less.

(c) Butadiene contains 1,2-butadiene.

(d) The weight average molecular weight (Mw) is 1,000 or more.

(e) The unbrominated non-aromatic double bond content obtained by ¹ H-NMR spectroscopy is less than 50% based on the non-aromatic double bond content of the copolymer before bromination.

(f) The 5% weight loss temperature obtained by thermogravimetric analysis (TGA) is above 200°C.

Among them, more preferred ones include brominated styrene-butadiene block copolymers and brominated styrene-butadiene random having the characteristics (a) to (f) above and in which the vinyl aromatic hydrocarbon is styrene. Copolymers, brominated styrene-butadiene graft copolymers, etc. Tejia is a brominated styrene-butadiene block copolymer. Specific examples include commercially available products such as "EMERALD INNOVATION 3000" from Lanxess Company, "FR122P" from ICL Company, and "GREEN CREST" from Albemarle Company.

In the present invention, the addition amount of the brominated polymer flame retardant is adjusted so that the bromine content in the resin composition becomes 18 mass % or more and 42 mass % or less.

《(B) Styrenic resin》

Examples of the (B) styrenic resin used in the resin composition of the present invention include homopolymers of styrene, copolymers of monomers copolymerizable with styrene, and rubber-reinforced ones. Styrenic resin. For example, polystyrene, rubber-reinforced polystyrene (HIPS), acrylonitrile-styrene copolymer resin (AS), acrylonitrile-butadiene-styrene copolymer resin (ABS), acrylonitrile-acrylic rubber-benzene Ethylene copolymer resin (AAS), acrylonitrile-ethylene propylene rubber-styrene copolymer resin, acrylonitrile-chlorinated polyethylene-styrene copolymer resin, styrene-butadiene copolymer resin, etc. These styrenic resins may be used alone or two or more types may be used together. Preferably polystyrene.

"(C) Stabilizer"

The stabilizer (C) is not particularly limited, and examples thereof include antioxidants, halogen scavengers, novolak-type epoxy resins, alkyl phosphites, and the like. (C) The stabilizer is preferably at least two selected from the group consisting of antioxidants, halogen scavengers, novolak-type epoxy resins, and alkyl phosphites.

Examples of antioxidants include phenol-based antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, and the like. Preferred are phenol-based antioxidants, particularly hindered phenol-based antioxidants. Examples of hindered phenol-based antioxidants include octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and ethylidenebis(oxyethylene)bis[3 -(5-tert-butyl-4-hydroxy-m-tolyl)propionate], 4,6-bis(octylthiomethyl)-o-cresol, 4,6-bis[(dodecyl thio)methyl]-o-cresol, 2,4-dimethyl-6-(1-methylpentadecyl)phenol, 4[methylene-3-(3,5-di-tertiary Butyl-4-hydroxyphenyl)propionate]methane, DL-α-tocopherol, 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)- 4-Methylphenyl acrylate, 2-[1-(2-hydroxy-3,5-di-tertiary pentylphenyl)ethyl]-4,6-di-tertiary pentylphenyl acrylate , 4,4'-thiobis(6-tert-butyl-3-methylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl) Butane, 4,4'-butylene bis(3-methyl-6-tert-butylphenol), etc.

The halogen scavenger is a component that captures free halogen generated during the manufacturing steps of the resin composition. Examples include magnesium carbonate compounds (dolomite-based compounds, hydrotalcite-based compounds, etc.), magnesium perchlorate compounds, aluminosilicate compounds (zeolite, etc.), organic tin compounds, and the like. Among them, dolomite-based compounds and hydrotalcite-based compounds are preferred from the viewpoint of the effect of suppressing the generation of black foreign matter. The dolomite compound is CaMg(CO ₃ ) ₂ or a compound containing it, and the hydrotalcite compound is one of the naturally occurring clay minerals represented by Mg ₆ Al ₂ (OH) ₁₆ CO ₃ ‧nH ₂ O, etc. These halogen scavengers can be used alone, but by using a dolomite-based compound and a hydrotalcite-based compound in combination, in addition to the effect of suppressing the generation of black foreign matter, the generation of discoloration can also be effectively suppressed. The mass ratio of the dolomite-based compound and the hydrotalcite-based compound is preferably dolomite-based compound / hydrotalcite-based compound = 10/90 to 90/10, and more preferably dolomite-based compound / hydrotalcite-based compound = 30/70 to 70/30.

Commercially available novolak type epoxy resins can be used. For example, cresol novolak type epoxy resin and phenol novolac type epoxy resin. Cresol novolak type epoxy resin is preferred.

Commercially available alkyl phosphites can be used. For example, bis(2,4-diisopropylphenylphenyl)pentaerythritol diphosphite, distearylpentaerythritol diphosphite and di-(2,4-di-(tert-butyl)phenyl)pentaerythritol Diphosphite.

The added amount of the (C) stabilizer is preferably 5 parts by mass or more and 30 parts by mass or less based on 100 parts by mass of the total of (A) brominated polymer flame retardant and (B) styrene-based resin. The amount of antioxidant added is preferably 0.8 parts by mass or more and 7 parts by mass or less. The added amount of the halogen scavenger is preferably 0.8 parts by mass or more and 15 parts by mass or less, and more preferably 5 parts by mass or more and 10 parts by mass or less. The addition amount of the novolak type epoxy resin is preferably 4 parts by mass or more and 25 parts by mass or less. The amount of alkyl phosphite added is preferably 4 parts by mass or more and 25 parts by mass or less. If this range is within this range, the thermal stability of the brominated polymer flame retardant in the resin composition will be improved, and the occurrence of black foreign matter or discoloration caused by thermal degradation of the brominated polymer flame retardant will be effectively suppressed. .

"(D) Liquid paraffin or epoxidized vegetable oil"

The liquid paraffin used in the present invention may be a well-known mixture of extremely pure liquid saturated hydrocarbons (called white oil) defined as a lubricating oil fraction at the boiling point.

As the epoxidized vegetable oil used in the present invention, commercially available ones can be used. For example, epoxidized soybean oil and epoxidized linseed oil. Preferred is epoxidized soybean oil.

(D) The added amount of liquid paraffin or epoxidized vegetable oil is preferably 1 part by mass or more and 8 parts by mass relative to the total of 100 parts by mass of (A) brominated polymer flame retardant and (B) styrene resin. parts or less, more preferably 3 parts by mass or more and 6 parts by mass or less. If it is within this range, the thermal stability of the (A) brominated polymer flame retardant in the resin composition will be improved, and the thermal degradation of the (A) brominated polymer flame retardant will be effectively suppressed. The occurrence of black foreign matter or discoloration.

"Other additives"

The resin composition of the present invention may be added with other additives within the scope that does not impair the effects of the present invention. For example, fatty acid-based lubricants such as stearic acid and palmitic acid, aliphatic amide-based lubricants such as stearic acid amide and ethyl bis-stearic acid amide, and metallic soap-based lubricants such as zinc stearate and magnesium stearate. Lubricants such as lubricants, fillers such as talc, mica, and silica, reinforcing agents such as glass fiber, colorants such as pigments and dyes, flame retardant additives such as antimony trioxide, nonionic surfactants, and cationic surfactants. agent and other antistatic agents.

"Manufacturing Method"

The manufacturing method of the resin composition of the present invention includes premixing (pre-blending) of at least fully mixing (A) brominated polymer flame retardant and (D) liquid paraffin or epoxidized vegetable oil before melting and kneading. steps. During premixing, (B) styrenic resin, (C) stabilizer, and other additives may be added if sufficient mixing is possible. (D) Liquid paraffin or epoxidized vegetable oil can be added from other feeders separately from the premix, but if (A) brominated polymeric flame retardant and (D) liquid paraffin or epoxidized vegetable oil are not premixed If it is added from another feeder and melted and kneaded, black foreign matter or discoloration caused by thermal degradation of (A) brominated polymer flame retardant will be produced. Examples of the premixing method include a method using a mixing device such as a stirrer type mixer, a V-type blender, and a drum type mixer.

The manufacturing method of the resin composition of the present invention includes the step of melting and kneading the premixed blend through an extruder at a resin temperature of less than 210°C. The extrusion melt-kneading method is not particularly limited, and known melting technology can be applied. As better melting and kneading devices, there are single-screw extruders, special single-screw extruders, and twin-screw extruders. A twin-screw extruder is preferred. As the melting technology of the extruder, there is a method of supplying the blend from the side feeder in the middle of the kneading device, and a method of supplying the liquid from the feed nozzle with a discharge pressure equal to or higher than the resin pressure using a known liquid transfer pump. method.

"Formed Body"

The first molding system of the present invention molds the styrene-based flame-retardant resin composition produced by the production method of the present invention. Furthermore, the second molding system of the present invention molds the styrene-based flame-retardant resin composition produced by the production method of the present invention and further styrene-based resin. The second molding system of the present invention uses a styrene-based flame-retardant resin composition produced by the production method of the present invention as a molded body as a masterbatch. Further examples of the styrene-based resin include the styrene-based resin described as (B) styrene-based resin. As the molding method, known methods such as injection molding and extrusion molding can be applied.

[Example]

Hereinafter, the present invention will be specifically described using examples. However, the present invention is not limited to these examples.

[(A) Brominated polymer type flame retardant]

"EMERALD INNOVATION 3000" manufactured by Lanxess Co., Ltd. (brominated styrene-butadiene block copolymer having the characteristics (a) to (f) above, bromine content: 60 mass%)

[(B) Styrenic resin]

A styrene homopolymer (polystyrene) having a weight average molecular weight (Mw) of 200,000 and a methanol-soluble content of 1.2% by mass was used. In addition, the weight average molecular weight (Mw) and the methanol-soluble content were measured by the following method.

<Measurement of Weight Average Molecular Weight (Mw)>

Gel permeation chromatography (GPC, Gel Permeation Chromatography) was used to measure under the following conditions.

GPC model: "Shodex GPC-101" manufactured by Showa Denko Co., Ltd.

Column: "PLgel 10μm MIXED-C" manufactured by Polymer Laboratories

Mobile phase: chloroform

Sample concentration: 0.2 mass%

Temperature: 40℃ (oven)

Detector: Differential Refractometer

The molecular weight of each component in the present invention is measured by calculating the molecular weight at each dissolution time from the dissolution curve of monodisperse polystyrene, and calculating it in the form of molecular weight converted to polystyrene.

<Determination of methanol-soluble content>

Dissolve 1 g of sample in 40 ml of solvent (methyl ethyl ketone), reprecipitate polystyrene with 10 times the amount of poor solvent (methanol) 400 ml, determine the mass of reprecipitated polystyrene, and use the residue as methanol Amount of soluble ingredients.

[(C) Stabilizer]

C-1: Antioxidant "Irganox 1076" produced by BASF Japan (3-(3,5-di-tert-butyl-4-hydroxyphenyl)octadecylpropionate)

C-2: Halogen capture agent "PLENLIZER HC-100B" manufactured by Ajinomoto Fine-Techno Co., Ltd. (dolomite-based compound)

C-3: Halogen scavenger "MC-63A" manufactured by Nitto Chemical Co., Ltd. (hydrotalcite-based compound)

C-4: Cresol novolak type epoxy resin "ARALDITE (registered trademark) ECN 1280" manufactured by Huntsman Japan Co., Ltd.

[(D) Liquid paraffin or epoxidized vegetable oil]

D-1: Liquid paraffin "Crystol N352" manufactured by Exxon Mobil Corporation

D-2: Epoxidized soybean oil "New Sizer 510R" manufactured by NOF Co., Ltd.

(Examples 1 to 4, Comparative Examples 1 to 6)

According to the mixing amount shown in Table 1, put each component into a mixer for pre-blending (pre-mixing) (Comparative Examples 1 and 2 did not perform pre-blending of component (A) and component (D)), and use a quantitative The feeder supplies the blended material to a twin-screw extruder ("TEM26SS: 14 barrels" manufactured by Toshiba Corporation) at a cylinder temperature of 180°C (220°C in Comparative Example 3) and a total supply volume of 30kg/hour. , melt and knead under the extrusion conditions of screw speed 300rpm. Furthermore, in Comparative Examples 1 and 2, (B) styrene resin, (C) stabilizer and (D) liquid paraffin or epoxidized vegetable oil were pre-blended, but (A) brominated polymer flame retardant Feed separately. The extruded strands are water-cooled and then introduced into a pelletizer to obtain pellets of the resin composition. The resin temperature is measured by inserting a resin thermometer into the die nozzle hole of the extruder. The bromine content in the obtained resin composition particles was measured by the following method, and the following foreign matter evaluation was performed. The results are shown in Table 1.

[Method for determination of bromine content]

The bromine content in the particles of the resin composition was measured by combustion-ion chromatography under the following conditions.

Model: "AQF-100" made by Mitsubishi Chemical Co., Ltd. and "DX-120" made by Dionex Corporation

Combustion tube temperature: 1000℃

Detector: Conductivity detector

Pipe string: AS12A

Flow rate: 1.5ml/min

Eluent composition: 2.7mM-Na ₂ CO ₃ +0.3mM-NaHCO ₃

Sample introduction volume: 5μl

Sample volume: 3mg

[Foreign body evaluation]

Using an injection molding machine ("J100E-P" manufactured by Nippon Steel Works Co., Ltd.), the particles of the resin composition are molded under the conditions of resin temperature 180°C and mold temperature 40°C. Length × width × thickness = 90mm × 90mm × 2mm molded body. Observe the occurrence of black foreign matter visually and evaluate according to the following criteria.

○: 0 or more and 4 or less black foreign matters are generated.

×: 5 or more black foreign objects were generated.

As can be seen from Table 1, according to the embodiments of the present invention, those that meet the requirements of the present invention do not produce foreign matter caused by the deterioration of the brominated polymer type flame retardant. However, it was found that in the comparative examples that did not meet the requirements of the present invention, the manufacturer produced foreign matter caused by the deterioration of the brominated polymer type flame retardant.

Claims (6)

A method for manufacturing a styrene-based flame-retardant resin composition, which is a method for manufacturing a styrene-based flame-retardant resin composition, characterized in that: the aforementioned styrene-based flame-retardant resin composition contains (A) brominated polymer type Flame retardant, (B) styrenic resin, (C) stabilizer, and (D) liquid paraffin, the bromine content is 18 mass % or more and 42 mass % or less, and at least the aforementioned (A) brominated polymer After the type flame retardant is mixed with the aforementioned (D) liquid paraffin, it is melted and kneaded by an extruder at a resin temperature of less than 210°C. Compared with the aforementioned (A) brominated polymer type flame retardant and the aforementioned (B) The aforementioned (C) stabilizer is contained in a total of 100 parts by mass of the styrene resin from 5 to 30 parts by mass, and the liquid paraffin (D) is contained in a range from 1 to 8 parts by mass. The method for manufacturing a styrenic flame-retardant resin composition according to claim 1, wherein the stabilizer (C) is at least one selected from the group consisting of antioxidants, halogen scavengers, novolak-type epoxy resins, and alkyl phosphites. 2 or more types. The method for producing a styrenic flame-retardant resin composition according to claim 1 or 2, wherein the (A) brominated polymer flame retardant (a) has butadiene and vinyl aromatic hydrocarbons as monomers Copolymer of ingredients, (b) the content of vinyl aromatic hydrocarbon monomer in the copolymer before bromination is 5 mass% or more and 90 mass% or less, (c) butadiene contains 1,2-butadiene Alkene, (d) the weight average molecular weight (Mw) is more than 1,000, (e) the unbrominated non-aromatic double bond content obtained by ¹ H-NMR spectroscopy is based on the non-aromatic double bonds of the copolymer before bromination The content is less than 50% based on the basis, and (f) the 5% weight loss temperature obtained by thermogravimetric analysis (TGA) is above 200°C. The method for manufacturing a styrene-based flame-retardant resin composition according to claim 1 or 2, wherein the aforementioned extruder is a twin-screw extruder. A flame-retardant resin molded article characterized by containing a styrene-based flame-retardant resin composition produced by the method for producing a styrene-based flame-retardant resin composition according to any one of claims 1 to 4. A flame-retardant resin molded article characterized by containing a styrene-based flame-retardant resin composition produced by the method for producing a styrene-based flame-retardant resin composition according to any one of claims 1 to 4, and further styrenic resins.