CN109912957B

CN109912957B - Resin composition, method for producing resin composition, and molded article

Info

Publication number: CN109912957B
Application number: CN201811220317.0A
Authority: CN
Inventors: 吉田浩一郎; 宫本朗
Original assignee: Asahi Kasei Corp
Current assignee: Asahi Kasei Corp
Priority date: 2017-12-12
Filing date: 2018-10-19
Publication date: 2024-07-16
Anticipated expiration: 2038-10-19
Also published as: JP6990571B2; JP2019104824A; CN109912957A

Abstract

The invention provides a resin composition, a method for producing the resin composition, and a molded body, which have excellent fluidity and appearance and high flame retardance. A resin composition comprising: the shrinkage rate of a test piece of a resin composition produced by a method comprising (a) a polyphenylene ether resin, (b) a styrene resin, (c) a phosphorus compound, (d) an inorganic filler and (e) polytetrafluoroethylene, wherein the resin composition comprises 35 to 60 mass% of component (d), and the shrinkage rate of the test piece represented by the following formula is 6 to 20% after aging the test piece of the resin composition at a temperature of 150 ℃ for 24 hours, wherein the test piece is produced by a method comprising the steps of forming the test piece of the resin composition by a method comprising 125mm in length in the flow direction, 13mm in length in the vertical direction and 1.6mm in thickness. The shrinkage rate [% ] = ((length of test piece in flow direction before aging [ mm ] -length of test piece in flow direction after aging [ mm ])/(length of test piece in flow direction before aging [ mm ])) x 100.

Description

Resin composition, method for producing resin composition, and molded article

Technical Field

The present invention relates to a resin composition, a method for producing the resin composition, and a molded article.

Background

Conventionally, polyphenylene ether resins have been widely used in home appliances, OA equipment, automobile parts, and the like because they have excellent electrical insulation properties, heat resistance, hydrolysis resistance, and flame retardancy.

In these applications, high flame retardancy is required due to a problem such as fire, and the polyphenylene ether resin can easily obtain flame retardancy by adding a phosphorus compound without using a halide. In addition, a reinforcing resin composition containing an inorganic filler is often used because of the need for higher rigidity, heat resistance, and dimensional properties.

In general, when an inorganic filler is blended, flame retardancy, fluidity and appearance are deteriorated. In particular, flame retardancy has been demanded to be more severe than before in recent years. In addition, since these materials are often molded with thin walls, there is a demand for good flowability (molding processability) in injection molding.

As a means for meeting the above-mentioned requirements, a polyphenylene ether resin composition which is excellent in balance of fluidity, mechanical properties and the like and flame retardancy by blending a styrene-acrylonitrile copolymer has been disclosed in the prior art (for example, see patent document 1).

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 9-31321

Disclosure of Invention

Problems to be solved by the invention

However, even the resin material disclosed in patent document 1 has room for further improvement in terms of achieving a high level of flame retardancy which has been demanded in recent years.

Accordingly, an object of the present invention is to provide a resin composition having excellent fluidity and appearance and a high level of flame retardancy, a method for producing the resin composition, and a molded article.

Means for solving the problems

As a result of intensive studies to solve the above problems, it has been found that a resin composition comprising a polyphenylene ether resin, a styrene resin, a phosphorus compound, an inorganic filler and polytetrafluoroethylene is excellent in fluidity and appearance and can attain a high level of flame retardancy by controlling the content of the inorganic filler and the heat shrinkage after heat aging within specific ranges, and the present invention has been completed.

Namely, the present invention is as follows.

[1]

A resin composition comprising:

(a) A polyphenylene ether resin,

(B) A styrene resin,

(C) A phosphorus compound,

(D) Inorganic filler material

(E) The preparation method comprises the steps of (1) polytetrafluoroethylene,

It is characterized in that the method comprises the steps of,

The resin composition contains 35 to 60 mass% of the component (d),

A test piece of the above resin composition, which was produced in a dimension of 125mm in the flow direction, 13mm in the vertical direction and 1.6mm in thickness, was aged at 150℃for 24 hours, and the shrinkage of the test piece represented by the following formula was 6% to 20%.

The shrinkage rate [% ] = ((length of test piece in flow direction before aging [ mm ] -length of test piece in flow direction after aging [ mm ])/(length of test piece in flow direction before aging [ mm ])) x 100

[2]

The resin composition according to the item [1], wherein the resin composition comprises, based on 100 parts by mass of the total of the component (a), the component (b) and the component (c)

50 To 70 parts by mass of the component (a),

10 To 30 parts by mass of the component (b),

10 To 30 parts by mass of the component (c), and

0.05 To 1 part by mass of the component (e).

[3]

The resin composition according to [1] or [2], wherein the component (a) comprises

(A-1) a polyphenylene ether-based resin having a reduced viscosity of 0.45dL/g to 0.55dL/g, and

(A-2) a polyphenylene ether resin having a reduced viscosity of 0.35dL/g to 0.45dL/g,

The content of the component (a-2) is 60 to 90 parts by mass based on 100 parts by mass of the total of the component (a-1) and the component (a-2).

[4]

The resin composition according to any one of [1] to [3], wherein the component (d) is at least one selected from glass fibers and mica.

[5]

The resin composition according to any one of [1] to [4], wherein the component (c) is a condensed phosphate compound.

[6]

A molded article comprising the resin composition according to any one of [1] to [5 ].

[7]

A method for producing the resin composition according to any one of [1] to [5], comprising the steps of:

the above components (a) to (e) are melt kneaded using an extruder.

[8]

The method for producing a resin composition according to [7], wherein the method comprises the steps of:

The powder polytetrafluoroethylene and/or modified polytetrafluoroethylene of the component (e) and at least one of the components (a) to (d) are dry-blended and fed into the extruder.

[9]

The method for producing a resin composition according to [8], wherein the step of supplying comprises the steps of:

The powder polytetrafluoroethylene and/or modified polytetrafluoroethylene of the component (e) is dry-blended with the whole or a part of the component (a) and fed into the extruder.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, there can be provided a resin composition having excellent fluidity and appearance and having a high level of flame retardancy, a method for producing the resin composition, and a molded article.

Drawings

Fig. 1 is a schematic view showing screw structures and set temperatures of barrels of twin-screw extruders used in examples and comparative examples.

Detailed Description

Hereinafter, a specific embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail. The present embodiment below is an example for explaining the present invention, and the present invention is not limited to the following embodiment. The present invention can be implemented by appropriately modifying the present invention within the scope of the gist thereof.

< Resin composition >

The resin composition of the present invention is a resin composition comprising (a) a polyphenylene ether resin, (b) a styrene resin, (c) a phosphorus compound, (d) an inorganic filler, and (e) polytetrafluoroethylene, wherein the resin composition comprises 35 to 60 mass% of the component (d), and a shrinkage rate of the test piece of the resin composition produced in a size of 125mm in length in the flow direction, 13mm in length in the vertical direction, and 1.6mm in thickness is 6 to 20% after aging at a temperature of 150 ℃ for 24 hours.

The shrinkage is more preferably 7 to 18%, and still more preferably 7 to 15%.

When the shrinkage is 6% or more, the molten drop resistance and the appearance at the time of combustion are excellent; when the content is 20% or less, the fluidity and flame retardancy are excellent.

< Shrinkage of test piece of resin composition >

In the present application, "aging" means to stand at a high temperature for a certain period of time, the temperature being 150 ℃ and the time being 24 hours.

The test piece of the resin composition was produced from the dried resin composition pellets by using an injection molding machine, and had a length in the flow direction of 125mm, a length in the vertical direction of 13mm and a thickness of 1.6 mm.

In the present application, the "flow direction" means a direction (MD) in which the resin composition flows when the resin composition is injection molded, and the "vertical direction" means a width direction (TD) perpendicular to the "flow direction".

The shrinkage (%) of the test piece can be determined by the following formula.

The shrinkage of the test piece is 6% to 20%, more preferably 7% to 18%, and still more preferably 7% to 15%. When the shrinkage is 6% or more, the molten drop resistance and the appearance at the time of combustion are excellent; when the content is 20% or less, the fluidity and flame retardancy are excellent.

The shrinkage of the test piece of the resin composition can be measured specifically by the method described in examples described later.

Examples of the method for increasing the shrinkage of the test piece after aging include: increasing the content of the component (e) in the resin composition; improving the dispersibility of the component (e); increasing the fibril structure of component (e); etc.

In contrast, as a method for reducing the shrinkage, there is mentioned, for example: reducing the content of component (e) in the resin composition; reducing the dispersibility of component (e); reducing the fibril structure of component (e); etc.

In addition, if the screw speed of the extruder is increased, the dispersibility of the component (e) is improved, but the fibril structure of the component (e) is easily broken; conversely, when the screw speed of the extruder is reduced, the dispersibility of the component (e) is reduced, but the fibril structure of the component (e) is hardly broken, and thus the screw speed is appropriately adjusted to adjust the shrinkage.

In the screw structure, if the kneading property is high, the dispersibility of the component (e) is improved, but the fibril structure of the component (e) is easily broken; in contrast, when the composition has low kneading property, dispersibility of the component (e) is lowered, but the fibril structure of the component (e) is hardly broken, and thus the screw composition is appropriately adjusted to adjust the shrinkage.

In this way, the shrinkage ratio can be adjusted by the content of the components (a) to (e) in the resin composition, the mixing method of the raw materials, the method of charging the raw materials into the extruder, the screw configuration, the rotation speed of the screw of the extruder in the kneading stage, the kneading temperature, and the like.

- (A) polyphenylene ether-based resin

(A) The polyphenylene ether resin (sometimes referred to as "PPE" or simply as "(a) component" in the present specification) may be a homopolymer (homopolymer) of phenylene ether or a copolymer (copolymer) of phenylene ether and another monomer.

The component (a) may be used alone in an amount of 1 or in an amount of 2 or more.

Examples of the component (a) include homopolymers and/or copolymers having a repeating unit structure represented by the following formula (1) (a unit structure derived from a phenylene ether).

[ Chemical formula 1]

[ Wherein R ¹、R²、R³ and R ⁴ each independently represent a monovalent group selected from the group consisting of a hydrogen atom, a halogen atom, a primary alkyl group having 1 to 7 carbon atoms, or a secondary alkyl group having 1 to 7 carbon atoms, a phenyl group, a haloalkyl group, an aminoalkyl group, a hydrocarbyloxy group, and a halohydrocarbonoxy group having at least 2 carbon atoms separating the halogen atom and the oxygen atom. ]

Examples of the component (a) include homopolymers such as poly (2, 6-dimethyl-1, 4-phenylene ether), poly (2-methyl-6-ethyl-1, 4-phenylene ether), poly (2-methyl-6-phenyl-1, 4-phenylene ether), and poly (2, 6-dichloro-1, 4-phenylene ether); copolymers of 2, 6-dimethylphenol with other phenols (e.g., 2,3, 6-trimethylphenol, 2-methyl-6-butylphenol), and the like. Among them, poly (2, 6-dimethyl-1, 4-phenylene ether), a copolymer of 2, 6-dimethylphenol and 2,3, 6-trimethylphenol is preferred, and poly (2, 6-dimethyl-1, 4-phenylene ether) is more preferred.

The method for producing the component (a) can be any conventionally known method. The method for producing the component (a) includes, for example: a method of producing a catalyst by oxidizing and polymerizing 2, 6-xylenol or the like using a complex of a copper salt and an amine; japanese patent application laid-open No. Sho 50-150798, japanese patent application laid-open No. Sho 50-051197, japanese patent application laid-open No. Sho 63-152628, and the like.

The reduced viscosity of the component (a) (0.5 g/dL in chloroform, 30 ℃ C., measured by a Ubbelohde viscometer) is preferably 0.7dL/g or less, more preferably 0.6dL/g or less, from the viewpoint of fluidity; from the viewpoint of the anti-dripping property, it is preferably 0.2dL/g or more, more preferably 0.3dL/g or more.

As the above-mentioned component (a), two or more kinds of polyphenylene ethers having different reduced viscosities may be used in combination. The component (a) preferably contains a polyphenylene ether resin having a reduced viscosity of 0.45dL/g to 0.55dL/g, preferably 0.48dL/g to 0.53dL/g, and a polyphenylene ether resin having a reduced viscosity of 0.35dL/g to 0.45dL/g, preferably 0.38dL/g to 0.43dL/g, in terms of balance between fluidity and anti-dripping property at the time of burning, and the content of the component (a-2) is 60 parts by mass to 90 parts by mass, more preferably 65 parts by mass to 80 parts by mass, relative to 100 parts by mass of the total of the component (a-1) and the component (a-2).

The component (a) may contain a modified polyphenylene ether which is wholly or partially modified.

The modified polyphenylene ether referred to herein means a polyphenylene ether modified with a modifying compound (hereinafter sometimes simply referred to as "modifying compound") having at least 1 carbon-carbon double bond and/or triple bond in the molecular structure and having at least 1 group selected from the group consisting of a carboxylic acid group, an acid anhydride group, an amino group, a hydroxyl group and a glycidyl group. The modifying compound may be used alone in an amount of 1 or 2 or more kinds thereof may be used in combination.

The method for producing the modified polyphenylene ether is not limited to the following method, and examples thereof include: a method of reacting a polyphenylene ether with a modifying compound in the presence or absence of a radical initiator (1) without melting the polyphenylene ether at a temperature in the range of 100 ℃ or more and less than the glass transition temperature of the polyphenylene ether; (2) A method in which a polyphenylene ether and a modified compound are melt-kneaded and reacted at a temperature in the range of 360 ℃ or higher than the glass transition temperature of the polyphenylene ether; (3) A method of reacting a polyphenylene ether and a modifying compound in a solution at a temperature less than the glass transition temperature of the polyphenylene ether; and the like, any of these methods may be used, and from the viewpoint of productivity, the method of (1) or (2) is preferable.

Next, the above-mentioned modifying compound used for producing the modified polyphenylene ether will be described.

Examples of the modified compound having a carbon-carbon double bond and having a carboxylic acid group and/or an acid anhydride group include maleic acid, fumaric acid, chloromaleic acid, cis-4-cyclohexene-1, 2-dicarboxylic acid, and acid anhydrides thereof.

Among them, maleic acid, fumaric acid and maleic anhydride are preferable from the viewpoint of reactivity with the polyphenylene ether resin, and fumaric acid and maleic anhydride are more preferable. In addition, a compound in which 1 or 2 of 2 carboxyl groups of the unsaturated dicarboxylic acid are ester-forming may be used as the modifying compound.

Examples of the modified compound having a carbon-carbon double bond and a hydroxyl group include unsaturated alcohols represented by the general formula C _nH_2n-1 OH (n is a positive integer), unsaturated alcohols represented by the general formula C _nH_2n-3 OH (n is a positive integer of 2 or more), unsaturated alcohols represented by the general formula C _nH_2n-5 OH (n is a positive integer of 3 or more), unsaturated alcohols represented by the general formula C _nH_2n-7 OH (n is a positive integer of 4 or more), and the like, such as allyl alcohol and 4-penten-1-ol.

Examples of the modified compound having a carbon-carbon double bond and a glycidyl group include allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, and epoxidized natural oil. Among them, glycidyl acrylate and glycidyl methacrylate are preferable.

The amount of the modifying compound to be added in the production of the modified polyphenylene ether is preferably 0.1 to 10 parts by mass, more preferably 0.3 to 5 parts by mass, and still more preferably 0.5 to 3 parts by mass, based on 100 parts by mass of the polyphenylene ether. When the amount is 0.1 part by mass or more, the effect of the modification of polyphenylene ether is easily exhibited; if it is 10 parts by mass or less, it is difficult to exhibit side effects due to modification.

When the modified polyphenylene ether is produced using the radical initiator, the amount of the radical initiator to be added is preferably 0.001 to 1 part by mass, more preferably 0.01 to 0.5 part by mass, and still more preferably 0.05 to 0.3 part by mass based on 100 parts by mass of the polyphenylene ether. When the amount is 0.001 parts by mass or more, the modification efficiency is excellent. When the amount is 1 part by mass or less, the modified polyphenylene ether is less likely to have a low molecular weight, and the balance between the modification ratio and physical properties is excellent.

The addition ratio of the modified compound to the modified polyphenylene ether is preferably 0.01 to 5% by mass, more preferably 0.05 to 3% by mass, and even more preferably 0.1 to 1% by mass, based on 100% by mass of the modified polyphenylene ether. The residual amount of the unreacted modified compound and/or the polymer of the modified compound in the modified polyphenylene ether is preferably less than 5% by mass, more preferably 3% by mass or less, and still more preferably 1% by mass or less.

In the resin composition of the present embodiment, the content of the component (a) is preferably 50 to 70 parts by mass, more preferably 55 to 70 parts by mass, and even more preferably 60 to 70 parts by mass, based on 100 parts by mass of the total of the component (a), the component (b), and the component (c), in terms of balance between flowability and flame retardancy.

Styrenic resin-

The styrene-based resin (in this specification, the term "component (b)") in this embodiment means a polymer obtained by polymerizing a styrene-based compound or polymerizing a styrene-based compound and a compound copolymerizable with the styrene-based compound in the presence or absence of a rubbery polymer.

(B) The styrene resin may be used alone in an amount of 1 or in an amount of 2 or more.

The styrene compound is a compound represented by the following formula (2).

[ Chemical formula 2]

(Wherein R represents hydrogen, lower alkyl or halogen, Z is selected from the group consisting of vinyl, hydrogen, halogen and lower alkyl, and p is an integer of 0to 5.)

Specific examples of the styrene compound include styrene, α -methylstyrene, 2, 4-dimethylstyrene, monochlorostyrene, p-methylstyrene, p-tert-butylstyrene, and ethylstyrene, and among these, styrene is preferable.

Examples of the compound copolymerizable with the styrene compound include methacrylates such as methyl methacrylate and ethyl methacrylate; unsaturated nitrile compounds such as acrylonitrile and methacrylonitrile; anhydrides such as maleic anhydride; and the like, together with a styrene compound. Among them, acrylonitrile is preferable.

The amount of the compound copolymerizable with the styrene compound is preferably 20% by mass or less, more preferably 15% by mass or less, relative to the total amount of the styrene compound and the compound copolymerizable with the styrene compound.

The rubber polymer may be a conjugated diene rubber, a copolymer of a conjugated diene and an aromatic vinyl compound, a hydrogenated product thereof, or an ethylene-propylene copolymer rubber. Of these, polybutadiene having a degree of unsaturation of 80% to 20% and polybutadiene having 90% or more of 1, 4-cis bond are more preferable.

The styrene-based resin (b) may be polystyrene, rubber-reinforced polystyrene (high impact polystyrene (HIPS)), styrene-acrylonitrile copolymer (AS resin), rubber-reinforced styrene-acrylonitrile copolymer (ABS resin), or other styrene-based copolymer. A combination of polystyrene and rubber-reinforced polystyrene containing 90% or more of polybutadiene having 1, 4-cis bonds is particularly preferably used. In addition, it is also preferable that homopolystyrene, atactic polystyrene, and syndiotactic polystyrene are all usable.

In the resin composition of the present embodiment, the content of the component (b) is preferably 10 to 30 parts by mass, more preferably 10 to 25 parts by mass, and even more preferably 10 to 20 parts by mass, based on 100 parts by mass of the total of the component (a), the component (b), and the component (c), in terms of flame retardancy and balance of fluidity.

Phosphorus compound (c)

The resin composition of the present embodiment contains (c) a phosphorus compound (in this specification, may be simply referred to as "(c) component").

The component (c) may be used alone in an amount of 1 or in an amount of 2 or more.

As the component (c), any phosphorus-containing flame retardant known in the art, such as an organic phosphorus compound, red phosphorus, and inorganic phosphate, can be used. Among them, a phosphate compound is preferable.

Examples of the component (c) include, but are not limited to, phosphate compounds such as trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, tricyclohexyl phosphate, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, xylylphenyl phosphate, dimethylethyl phosphate, methyldibutyl phosphate, ethyldipropyl phosphate, and hydroxyphenyl diphenyl phosphate; modified phosphate compounds obtained by modifying them with various substituents; various condensed phosphoric ester compounds of condensed type, and the like. Among these, condensed phosphate-based compounds are preferable.

The condensed phosphate compound preferably contains at least 1 selected from the group consisting of condensed phosphates represented by the following formula (3) and the following formula (4) as a main component.

The "main component" as used herein means that the content of at least 1 selected from the group consisting of aromatic condensed phosphoric esters represented by the following formula (3) and the following formula (4) is 90 mass% or more, preferably 95 mass% or more, and more preferably 100 mass% relative to 100 mass% of the component (c).

[ Chemical 3]

In the formula (3), Q ⁴¹、Q⁴²、Q⁴³ and Q ⁴⁴ are each independently an alkyl group having 1 to 6 carbon atoms; r ⁴¹ and R ⁴² are methyl; r ⁴³ and R ⁴⁴ are each independently a hydrogen atom or a methyl group; x is an integer of 0 or more; p ₁、p₂、p₃ and p ₄ are each an integer of 0 to 3; q ₁ and q ₂ are each an integer of 0 to 2. ]

[ Chemical formula 4]

In the formula (4), Q ⁵¹、Q⁵²、Q⁵³ and Q ⁵⁴ are each independently an alkyl group having 1 to 6 carbon atoms; r ⁵¹ is methyl; y is an integer of 0 or more; r ₁、r₂、r₃ and r ₄ are integers from 0 to 3 respectively; s ₁ is an integer of 0 to 2. ]

The condensed phosphate compound represented by the formula (3) and the condensed phosphate compound represented by the formula (4) may contain two or more molecules, respectively. In addition, x of the formula (3) and y of the formula (4) are preferably integers of 1 to 3.

Wherein R ⁴³ and R ⁴⁴ in the formula (3) preferably represent methyl groups, p ₁、p₂、p₃、p₄、q₁ and q ₂ are 0, and the condensed phosphate is contained in an amount of 50% by mass or more relative to 100% by mass of the component (c); q ⁴¹、Q⁴²、Q⁴³、Q⁴⁴、R⁴³ and R ⁴⁴ in the formula (3) represent methyl groups, Q ₁ and Q ₂ are 0, p ₁、p₂、p₃ and p ₄ are integers of 1 to 3, and x is an integer of 1 to 3 (especially x is 1). By using these condensed phosphoric ester compounds, the volatility of the resin composition during molding processing can be further reduced.

In the resin composition of the present embodiment, the content of the component (c) is preferably 10 to 30 parts by mass, more preferably 10 to 25 parts by mass, and even more preferably 15 to 25 parts by mass, based on 100 parts by mass of the total of the component (a), the component (b), and the component (c), in terms of balance between mechanical properties, heat resistance, fluidity, and flame retardancy.

Inorganic filler material

The inorganic filler (d) (in this specification, sometimes simply referred to as the "(d) component") included in the resin composition of the present embodiment includes glass fibers, glass flakes, mica, wollastonite, talc, calcined clay, and the like. In the case of low-dimensional anisotropy, glass beads and glass flakes are preferably selected; when high rigidity and high impact resistance are required, glass fibers and whiskers are preferably used; in order to impart conductivity, metal fibers are preferably selected; in the case where a high specific gravity is required, iron oxide is preferably selected. From the viewpoint of mechanical properties and flame retardancy, 1 or more selected from glass fibers and mica are preferable, and glass fibers and mica are more preferable.

The component (d) may be used alone or in combination of 1 or 2 or more, and may be used in combination of a surface treatment with a silane-based coupling agent and a bundling treatment with a bundling agent, if desired, within a range that does not impair the object of the present invention.

In the resin composition of the present embodiment, the content of the component (d) in the resin composition is 35 to 60% by mass, preferably 35 to 55% by mass, and more preferably 40 to 50% by mass, in terms of balance between fluidity and mechanical properties and dimensional characteristics.

Polytetrafluoroethylene (e)

The polytetrafluoroethylene (hereinafter, sometimes simply referred to as "component (e)") (PTFE) of the present embodiment has a fibril structure formed in polyphenylene ether, and thus has an improved effect of suppressing dripping, and is suitable as an anti-dripping agent.

The component (e) may be a homopolymer of tetrafluoroethylene, a copolymer of tetrafluoroethylene with vinylidene fluoride, trifluoroethylene, hexafluoropropylene, or the like, and may be used alone or in combination of 1 or 2 or more.

Among them, a modified PTFE containing 10 to 90 mass% (preferably 15 to 70 mass%) of PTFE and having improved handleability by other resins is preferably used. Such modified PTFE is described in, for example, japanese patent application laid-open No. 09-95583 and Japanese patent application laid-open No. 11-29679, and is sold under the trade names of METABLEN (Mitsubishi Yang Zhushi Co., ltd.) and BLENDEX 449 (Chemtura Co.).

As the form of adding PTFE to the resin composition, any of powder and dispersion may be used as long as the form of PTFE in the resin composition of the present embodiment can be obtained. In addition, a method of adding a masterbatch of PTFE with (a) a polyphenylene ether resin or another resin or the like is also considered.

In the case of the PTFE masterbatch, the masterbatch is heated twice at the time of producing the masterbatch and at the time of producing the resin composition. From the viewpoint of obtaining excellent melt drop resistance and appearance upon combustion, it is preferable to obtain the resin composition by one-time extrusion.

It is further preferable to use powder PTFE and/or modified PTFE, and it is preferable to dry mix at least one of the components (a) to (d) in the PTFE in advance and supply the mixture to an extruder. In addition, it is particularly preferable that the whole amount or only a part of the polyphenylene ether resin (a) is dry-blended in the PTFE in advance and fed into the extruder.

In the resin composition of the present embodiment, the content of the component (e) is preferably 0.05 to 1 part by mass, more preferably 0.1 to 0.8 part by mass, and even more preferably 0.2 to 0.5 part by mass, based on 100 parts by mass of the total of the component (a), the component (b), and the component (c), in terms of balance between fluidity and flame retardancy and anti-dripping property at the time of combustion. The content of the component (e) when the modified PTFE is used means the actual amount of PTFE in the modified PTFE.

< Additive >

In order to further impart other properties to the resin composition of the present embodiment, additives such as a plasticizer, an antioxidant, a stabilizer such as an ultraviolet absorber, an antistatic agent, a releasing agent, a dye/pigment, and other resins other than the above may be added to the resin composition within a range that does not impair the effects of the present invention. In addition, various flame retardants and flame retardant aids known in the prior art, for example, alkaline earth metal hydroxides such as magnesium hydroxide containing crystal water, aluminum hydroxide, alkali metal hydroxides, zinc borate compounds, zinc stannate compounds, and the like may be added to further improve flame retardancy.

The content of the additive may be 5% by mass or less relative to 100% by mass of the resin composition.

< Physical Properties of resin composition >

Fluidity-

The melt flow rate of the resin composition of the present embodiment is preferably 5g/10 min or more, more preferably 10g/10 min or more, from the viewpoint of more excellent flowability. In addition, from the viewpoint of the anti-dripping property in the combustion test, it is preferably 30g/10 minutes or less.

The melt flow rate of the resin composition may be measured in accordance with ISO1133, specifically, by the method described in examples described later.

Flame-retardant-

In the resin composition of the present embodiment, in the evaluation of flame retardancy by the UL94-V test using an injection test piece having a thickness of 1.6mm, the evaluation of V-0 and V-1 is preferable. More preferably V-0.

In addition, in the resin composition of the present embodiment, in the evaluation of flame retardancy by the UL94-5V test using an injection test piece having a thickness of 2.8mm, the evaluation of 5VA is preferable. More preferably, the evaluation of flame retardance by the UL94-5V test using an injection test piece having a thickness of 2.4mm is 5 VA.

The flame retardancy of the resin composition can be evaluated by the method described in examples described below.

< Method for producing resin composition >

The method for producing the resin composition of the present embodiment includes, for example, a method of melt-kneading the above components using a twin-screw extruder. Examples of the twin screw extruder include ZSK series manufactured by Coperion corporation, TEM series manufactured by toshiba machinery corporation, and TEX series manufactured by japan steel corporation.

The extruder preferably has an L/D (effective barrel length/inner barrel diameter) of 20 to 75, more preferably 30 to 60, from the viewpoint of kneading the components more uniformly and obtaining more excellent flame retardancy.

The extruder is not particularly limited in structure, and for example, a first raw material supply port is preferably provided on the upstream side in the raw material flow direction, a first vacuum exhaust port is provided downstream of the first raw material supply port, a second raw material supply port is provided downstream of the first vacuum exhaust port, a liquid charging pump is provided downstream of the second raw material supply port, a third raw material supply port is provided downstream of the liquid charging pump, and a second vacuum exhaust port is preferably provided downstream of the third raw material supply port. In particular, it is more preferable to have a kneading block upstream of the first vacuum vent, a kneading block between the second raw material supply port and the liquid feeding pump, and a kneading block between the third raw material supply port and the second vacuum vent.

The melt kneading temperature, screw rotation speed, and the like in the method for producing a resin composition of the present embodiment are not particularly limited, and suitable conditions may be appropriately selected from the range of 200 to 370℃for melt kneading and 100 to 1200rpm for screw rotation speed.

In terms of the resin composition exhibiting excellent melt drip resistance during combustion, the melt kneading temperature is preferably 280 to 320℃and the screw rotation speed is preferably 250 to 550rpm.

The screw structure provided in the barrel is not particularly limited, and may be a structure in which right-handed, left-handed, orthogonal (N-type) and reverse-fed (L-type) kneading disk elements are provided appropriately, and in particular, a structure in which at least 1 or more orthogonal (N-type) kneading disk elements, reverse-fed (L-type) kneading disk elements, and twin-screw reverse-feed (left-handed) screws are provided between the first raw material supply port and the second raw material supply port, respectively, is preferable from the viewpoint of exhibiting excellent resistance to molten drops during combustion. In addition, from the viewpoint of uniformly dispersing the inorganic filler, it is more preferable to provide a configuration in which a section including at least 2 orthogonal (N-type) kneading disk elements and at least 1 twin-screw reverse feed (left-handed) is provided between the third raw material supply port and the second vacuum exhaust port.

The raw material supply device for supplying the raw material to the twin-screw extruder is not particularly limited, and examples thereof include a single-screw feeder, a twin-screw feeder, a flat-plate feeder, and a rotary feeder. Among these, the weight loss compensation feeder is preferable in terms of less variation error in the raw material supply.

In the case of supplying a liquid raw material, the liquid raw material may be directly fed into the barrel system by using a liquid feeding pump or the like in the barrel portion of the extruder, whereby kneading is performed. The liquid feeding pump is not particularly limited, and examples thereof include a gear pump, a flange pump, and the like. Among these, a gear pump is preferable. Further, it is more preferable to heat a portion or the like of a flow path for the liquid raw material, such as a tank for storing the liquid raw material for the liquid feed pump, a pipe between the tank and the pump, and a pipe between the pump and the extruder barrel, by a heater or the like. This is preferable in terms of operability and the like because the viscosity of the liquid raw material can be reduced, and thus the load applied to the liquid feed pump can be reduced.

In the method for producing a resin composition according to the present embodiment, the total amount of the component (a), the total amount of the component (b), and the total amount of the component (e) are preferably added from the first raw material supply port (excluding the case where the total amount of the component (e) is added from the second raw material supply port), the remaining component (b) is added from the second raw material supply port (excluding the case where the total amount of the component (b) is added from the first raw material supply port), the total amount of the component (e) is not added from the first raw material supply port (excluding the case where the total amount of the component (e) is added from the first raw material supply port), the total amount of the component (d), or a part of the component (d) is added from the liquid charging pump, and the remaining component (d) is added from the third raw material supply port (excluding the case where the total amount of the component (d) is added from the second raw material supply port). Among them, the addition position of the component (e) is preferably from the first raw material supply port, in view of exhibiting excellent anti-dripping property at the time of combustion and appearance.

The method for supplying the component (e) to the extruder preferably includes the steps of: at least one of the components (a) to (d) is dry-blended in advance with the PTFE using powder PTFE and/or modified PTFE, and the resultant is fed to an extruder. In particular, from the viewpoint of exhibiting more excellent anti-dripping property and appearance at the time of combustion, it is preferable to include the following steps: the entire amount or only a part of the polyphenylene ether resin (a) is dry-blended in advance with the PTFE and fed into an extruder.

< Molded article >

The resin composition of the present embodiment can be molded into a molded article by molding. The molding method is not particularly limited, and known molding methods such as injection molding, blow molding, extrusion molding, sheet molding, and film molding can be used. The molded article obtained by molding the resin composition can be used as various molded articles, and is particularly suitable for use in home appliances, OA equipment, and the like. That is, the molded article of the present embodiment is a molded article comprising the above resin composition.

The molding method of the resin composition of the present embodiment is not particularly limited, and examples thereof include a method of molding using an injection molding machine. Such an injection molding machine IS not particularly limited, and examples thereof include "IS100GN" manufactured by TOSHIBA corporation.

The melting temperature, mold temperature, etc. in the molding method of the resin composition of the present embodiment may be appropriately selected from the range of 200 to 320 ℃ and 30 to 100 ℃, but are not particularly limited thereto.

Examples

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples. The raw materials used are as follows.

(A) Polyphenylene ether resin (PPE)

(A-1) Poly (2, 6-dimethyl-1, 4-phenylene ether) having a reduced viscosity (measured at 30 ℃ C. In a chloroform solution of 0.5 g/dL) of 0.52dL/g

(A-2) Poly (2, 6-dimethyl-1, 4-phenylene ether) having a reduced viscosity (measured at 30 ℃ C. In a chloroform solution of 0.5 g/dL) of 0.41dL/g

(B) Styrene resin

(B-1) High Impact Polystyrene (HIPS)

"CT60" manufactured by Petrochemical Co "

(B-2) styrene-Acrylonitrile copolymer (AS)

The AS copolymer of (b-2) was produced AS follows.

A mixed solution containing 4.7 parts by mass of acrylonitrile, 73.3 parts by mass of styrene, 22 parts by mass of ethylbenzene and 0.02 part by mass of t-butyl peroxyisopropyl carbonate as a polymerization initiator was continuously fed at a flow rate of 2.5 liters/hour to a complete mixing type reactor having a capacity of 5 liters, and polymerization was carried out at 142℃to obtain a polymer solution.

The obtained polymerization solution was continuously introduced into an extruder with a vent, unreacted monomers and solvents were removed at 260℃and 40Torr, and the polymer was continuously cooled and solidified, and was cut to obtain a styrene-acrylonitrile copolymer (hereinafter, sometimes referred to AS "AS") in the form of particles.

The styrene-acrylonitrile copolymer was analyzed for composition by infrared absorption spectrometry, and as a result, the acrylonitrile unit was 9 mass% and the styrene unit was 91 mass%. In addition, the melt flow rate of the styrene-acrylonitrile copolymer was 78g/10 min (measured at 220℃under a load of 10kg according to ASTM D1238).

(C) Phosphorus compound

Condensed phosphate compound (E890, trade name), manufactured by Daba chemical industry Co., ltd.)

(D) Inorganic filler

(D-1) mica

Trade name "s land 200HK", manufactured by west japan trade company, inc

(D-2) Glass Fiber (GF)

Trade name "megaly-doped, one-case-fiber REV 8"; owens Corning Japan company manufacture

(E) Polytetrafluoroethylene

Modified PTFE containing 50% by mass of an acrylate-methacrylate copolymer (trade name "METABLEN A3800", manufactured by Mitsubishi Yang Zhushi Co., ltd.)

The resin compositions obtained in examples and comparative examples were evaluated by the following methods and conditions.

< Shrinkage of test piece after aging >

The resin composition pellets obtained in examples and comparative examples were dried at 90℃for 1 hour. Test pieces having a length in the flow direction of 125mm, a length in the vertical direction of 13mm, and a thickness of 1.6mm were produced from the dried resin composition pellets using an IS-100GN injection molding machine (Toshiba instruments Co., ltd., cartridge temperature was set to 240℃to 280℃and mold temperature was set to 80 ℃).

After the test piece was aged at a temperature of 150℃for 24 hours, the shrinkage of the test piece was determined by the following formula.

< Appearance >

The resin composition pellets obtained in examples and comparative examples were dried at 90℃for 1 hour. Test pieces having a length in the flow direction of 90mm, a length in the vertical direction of 50mm, and a thickness of 2.5mm were produced from the dried resin composition pellets using an IS-100GN injection molding machine (Toshiba instruments Co., ltd., cartridge temperature was set to 240℃to 280℃and mold temperature was set to 80 ℃).

The appearance of the test piece was visually confirmed, and the test piece was judged according to the following evaluation criteria.

O (excellent): the filling material floats little.

Delta (pass): the filling material floats slightly more.

X (bad): the filling material floats up much.

< Melt Flow Rate (MFR) >)

Using the pellets of the resin compositions obtained in examples and comparative examples, the melt flow rate (g/10 minutes) was measured in accordance with ISO-1133 at 250℃under a load of 10 kg.

As an evaluation criterion, the larger the value of the melt flow rate, the more excellent the flowability is evaluated.

< Flame retardance >

V test-

Based on the UL94-V test, flame retardancy was evaluated using an injection molded test piece having a thickness of 1.6 mm.

First, the resin composition pellets obtained in examples and comparative examples were dried at 90℃for 1 hour. The dried pellets were fed to a coaxial screw type (trade name "IS-100GN", manufactured by toshiba machinery co-ltd.) injection molding machine (s-screw type) set at 240 to 280 ℃ and injection molded at a mold temperature of 80 ℃ to prepare test pieces having dimensions (125 mm long by 13mm wide by 1.6mm thick) specified in the standard.

The test piece was brought into contact with the flame of the gas lamp, and the degree of combustion was evaluated.

The flame retardant rating shows a rating of flame retardancy classified by the UL94-V test. For all test pieces, 5 were tested and the determination was made. The outline of the classification method is as follows.

V-0:5 pieces of the glass have a total burning time of 50 seconds or less and a maximum burning time of 10 seconds or less, and have no flame droplets

V-1: the total burning time of 5 is less than 250 seconds, the maximum burning time is less than 30 seconds, and no flame molten drop exists

5V test

Based on the UL94-5V test, flame retardancy was evaluated using an injection molded test piece having a thickness of 2.4mm and a thickness of 2.8 mm.

First, the resin composition pellets obtained in examples and comparative examples were dried at 90℃for 1 hour.

In the long sample, the dried pellets were supplied to a coaxial screw type injection molding machine (trade name "SH100C", manufactured by Sumitomo mechanical Co., ltd.) set at 220℃to 240℃and injection molded at a mold temperature of 30℃to prepare test pieces having dimensions (125 mm long by 13mm wide by 2.4mm thick and 2.8mm thick) specified in the standard.

In the plate-like sample, the dried pellets were supplied to a coaxial screw type injection molding machine (trade name "SH100℃", manufactured by Sumitomo heavy machinery industries Co., ltd.) set at 290℃to 310℃and injection molded at a mold temperature of 100℃to prepare test pieces having dimensions (150 mm long by 150mm wide by 2.4mm thick and 2.8mm thick) specified in the standard.

The flame retardant rating shows a rating of flame retardancy classified by the UL94-5V test. The test was performed with 5 long samples and the test was performed with 3 plate-like samples, thereby making a judgment. The outline of the classification method is as follows.

5VA: in the long sample, the total of the burning time and the light-emitting time after the 5 th contact with the flame was 60 seconds or less, and the plate-like sample was free from any holes after the contact with the flame.

Disqualification: the case where the criterion of 5VA was not satisfied was regarded as failure.

Hereinafter, each example and each comparative example will be described in detail.

As an apparatus for producing the resin composition, a twin screw extruder (trade name "TEM58SS", manufactured by Toshiba machinery Co., ltd.) was used. In this twin-screw extruder, the number of barrels is 13, 1 (first supply port), 6 (second supply port), and 9 (third supply port) are provided in the 1 st barrel, and 3 total supply ports are provided in the 9 th barrel, respectively, from the upstream in the flow direction of the raw material, a liquid feeding pump is provided in the 8 th barrel, and vacuum vents are provided in the 2 th barrels, 5 th and 12 th barrels. The method of supplying the raw material to the second supply port and the third supply port is a method of supplying the raw material from the extruder side opening port using a forced side feeder.

The screw structure provided in the cylinder and the set temperature of the cylinder in the production methods 1 to 4 are as described in fig. 1. The abbreviations of kneading disks used for the above-mentioned marks made of screws are as follows.

R1: kneading disk right-hand (L/D=1.03)

R2: kneading disk right-hand (L/D=0.51)

L: kneading disk left-handed (L/D=0.51)

N1: kneading disk neutrality (L/d=1.03)

N2: kneading disk neutrality (L/d=0.51)

Inverse: double-flighted screw reverse feed (L/d=0.39)

S: SME screw (L/d=0.78)

Examples 1 to 10 and comparative examples 1 to 6

In the twin-screw extruder set as described above, melt kneading was performed under the composition and production conditions shown in tables 1 and 3 at a discharge amount of 400 kg/hr to obtain pellets of the resin composition.

Example 11

In the twin-screw extruder set as described above, melt kneading was performed under the composition and production conditions shown in Table 2 at a discharge amount of 400 kg/hr. First, a first resin composition is produced, and then a second resin composition is produced using the first resin composition, to obtain pellets of the resin composition.

The resin compositions were evaluated by the above-described measurement methods, and the results are shown in tables 1 to 3.

[ Table 1]

[ Table 2]

[ Table 3]

As shown in tables 1,2 and 3, it can be seen that: examples 1 to 11, in which the shrinkage of the test piece after aging at 150℃for 24 hours was 6% to 20%, were excellent in fluidity, flame retardancy and mechanical properties.

Industrial applicability

According to the present invention, a resin composition excellent in appearance, fluidity, and flame retardancy at a high level can be provided, which has industrial applicability as a material for home appliances, OA equipment, and the like.

Claims

1. A resin composition comprising:

(a) A polyphenylene ether resin,

(B) A styrene resin,

(C) A phosphorus compound,

(D) Inorganic filler material

(E) The preparation method comprises the steps of (1) polytetrafluoroethylene,

It is characterized in that the method comprises the steps of,

The resin composition contains 35 to 60 mass% of the component (d),

A test piece of the resin composition produced in a dimension of 125mm in the flow direction, 13mm in the vertical direction and 1.6mm in thickness was aged at 150℃for 24 hours, and the shrinkage of the test piece represented by the following formula was 6 to 20%,

The composition comprises, relative to 100 parts by mass of the total of the component (a), the component (b) and the component (c)

50 To 70 parts by mass of the component (a),

10 To 30 parts by mass of the component (b),

10 To 30 parts by mass of the component (c), and

0.05 To 1 part by mass of the component (e),

The component (b) is at least one selected from the group consisting of polystyrene, high impact polystyrene HIPS, styrene-acrylonitrile copolymer AS resin, rubber reinforced styrene-acrylonitrile copolymer ABS resin,

The component (c) is a condensed phosphoric ester compound,

The component (d) is at least one selected from glass fiber and mica,

The component (e) is a modified polytetrafluoroethylene containing 10 to 90 mass% of polytetrafluoroethylene and having improved handleability by other resins.

2. The resin composition according to claim 1, wherein the component (a) comprises

3. A molded article comprising the resin composition according to claim 1 or 2.

4. A method for producing the resin composition according to claim 1 or 2, comprising the steps of:

And (c) melt-kneading the components (a) to (e) using an extruder.

5. The method for producing a resin composition according to claim 4, wherein the method comprises the steps of:

And dry-mixing the powder modified polytetrafluoroethylene of the component (e) with at least one of the components (a) to (d), and feeding the dry-mixed components into the extruder.

6. The method for producing a resin composition according to claim 5, wherein the step of supplying comprises the steps of:

the powder-modified polytetrafluoroethylene of the component (e) is dry-blended with the whole or a part of the component (a) and fed into the extruder.