KR100715367B1 - An auxiliary flame retardment providing an improved surface quality and anti-drop property - Google Patents

Abstract

The present invention relates to a flame retardant adjuvant using polytetrafluoroethylene, and more particularly, the present invention relates to a polytetrafluoroethylene and at least one monomer selected from the group consisting of styrene monomers and acrylic monomers. A flame retardant aid comprising a coating layer formed on the flame retardant aid according to the present invention provides excellent wake resistance and surface quality.

Flame Retardant Aids, Polytetrafluoroethylene, Coating

Description

AN AUXILIARY FLAME RETARDMENT PROVIDING AN IMPROVED SURFACE QUALITY AND ANTI-DROP PROPERTY}

1A is a photograph of a resin surface using a polytetrafluoroethylene dispersion as a flame retardant aid.

FIG. 1B is a SEM photograph showing the micromorphology of the resin surface using a polytetrafluoroethylene dispersion as a flame retardant aid.

Figure 2a is a photograph of the resin surface using a flame retardant aid according to the present invention.

Figure 2b is a SEM photograph showing the micromorphology of the resin surface using a flame retardant aid according to the present invention.

The present invention relates to a flame retardant aid used with a flame retardant to impart flame retardancy to a polymer resin, and more particularly to a flame retardant aid that improves the flame retardancy of a polymer resin together with a flame retardant, and exhibits a wake function and excellent surface quality. .

In order to flame retard the polymeric resin, flame retardants, flame retardant aids and other additives (eg dyes and pigments) have generally been used. Various flame retardants have been used, depending on the type of polymer resin, and flame retardant aids have been used that impart proper anti-dripping capability to meet the flame retardant test conditions specified by UL94.

As a conventional flame retardant aid, a flame retardant aid comprising a polytetrafluoroethylene (PTFE) component or a modified PTFE component is generally used. Flame retardant aids comprising a PTFE component are classified according to particle size. Among the widely used PTFE flame retardant aids are PTFE dispersions and PTFE powders, the physical properties of which are shown in Table 1.

PTFE dispersion PTFE powder Granularity About 0.4 ~ 0.6㎛ About 400 ~ 600㎛ Wake Great Great Surface quality Sunspot or blue spot Sunspot or blue spot Ease of Storage Poor long-term storage (deposition occurs after 3 months), and warmth is required in winter Raw materials clump together when stored below a certain temperature (19 ℃) and require separate storage facilities Easy processing of raw materials on site When mixing with solid materials, it is necessary to have a device for uniform mixing Incompatibility with other materials, coating on inner wall when mixing

Polymer resins containing PTFE dispersions show good traceability, but due to the fine dispersion of PTFE, black spots or blue dots appear on the surface of the polymer resin injection molding, and they cannot be used when stored for more than 3 months and are mixed with other solid materials. Handling is difficult and insufficiently mixed.

Polymer resins containing PTFE powder also exhibit excellent traceability, but black spots or blue spots appear on the surface of the injection molding, and blocking occurs at 19 ° C. or lower, making dispersion difficult and difficult to mix with other raw materials. In the mixing process, a building phenomenon occurs in which PTFE particles adhere to the inner wall of the mixer.

The present invention has been made to solve the above problems, an object of the present invention is to improve the injection surface quality of the polymer resin, to be stored for a long time, and easy to handle as a PTFE flame retardant aid, polytetrafluoroethylene, and styrene It is to provide a flame retardant aid comprising at least one monomer selected from the group consisting of monomers and acrylic monomers and comprising a coating layer formed on the outside of the polytetrafluoroethylene.

Another object of the present invention is to provide a flame retardant adjuvant comprising forming a coating layer on the outside of polytetrafluoroethylene in the presence of an anionic emulsifier and an initiator, the coating layer comprising at least one monomer selected from the group consisting of styrene monomers and acrylic monomers. It is to provide a manufacturing method.

It is yet another object of the present invention to provide a flame retardant resin composition comprising a flame retardant aid, flame retardant, and at least one resin selected from the group consisting of ABS, PC, HIPS, SAN, and PBT that provides improved surface quality and traceability. will be.

In order to solve the above problems, the present invention is polytetrafluoroethylene; And a coating layer formed on the outside of the polytetrafluoroethylene, wherein the coating layer provides a flame retardant aid including one or more monomers selected from the group consisting of styrene monomers and acrylic monomers.

Hereinafter, the present invention will be described in detail.

Abbreviations used in the present invention are as follows. PTFE stands for polytetrafluoroethylene. ASTM stands for American Society for Testing and Materials. ABS stands for acrylonitrile butadiene styrene. PC stands for polycarbonate. SAN stands for styrene acrylonitrile. PBT stands for polybutylene terephtalate. HIPS stands for high impact polystyrene. FR stands for flame retardant. In this specification, abbreviations and full names are used interchangeably and have the same meaning.

The flame retardant aid according to the present invention has a coating layer comprising styrene-based and / or acrylic-based on the outside of PTFE, thereby providing high fluidity and high surface quality when used in a polymer resin composition.

The coating layer preferably includes a first coating layer containing styrene monomer and formed on the surface of polytetrafluoroethylene, and a second coating layer containing acrylic monomer and formed on the surface of the first coating layer. In addition, the second coating layer preferably comprises a copolymer of a styrene monomer and an acrylic monomer.

The first coating layer formed on the surface of the PTFE serves to suppress the aggregation of the PTFE in the polymer resin and increase the fluidity to provide improved surface quality and trackability. Therefore, any coating layer capable of providing the above function to PTFE may be freely selected without limitation, but it is preferable to coat using a styrene monomer. However, only the first coating layer using the styrene-based monomer may cause PTFE to aggregate due to the cracking of the coating during the harsh working environment or processing. Therefore, it is preferable to further form a coating layer capable of imparting durability to the PTFE on which the first coating layer is formed. If the coating layer that can provide the function to PTFE can be freely selected without limitation, it is preferable to coat using an acrylic monomer.

The flame retardant aid according to the invention is in the form of particles and generally has a particle size of 0.2 to 0.6 μm, preferably 0.3 to 0.5 μm, more preferably 0.3 to 0.4 μm. Particle sizes smaller than 0.2 μm do not adversely affect the surface of the final resin, but PTFE having a particle size smaller than 0.2 μm is difficult to obtain commercially. If the particle size is larger than 0.6 mu m, the surface quality of the final resin is deteriorated.

In the present invention, PTFE having a molecular weight of 1,000,000 to 10,000,000, preferably 2,000,000 to 9,000,000 can be used, and in general, high molecular weight PTFE is preferred in terms of stability. Either powder or dispersion form may be used. PTFE used in the present invention also includes modified PTFE which can be used as a flame retardant aid. PTFE is commercially available in powder or dispersion form depending on the molecular weight. Specifically PTFE powders that may be used in the present invention include, but are not limited to, Teflon 6J (Mitsui-Dupont fluoro chemicals Co., Ltd), Polyfullon MPA500 or F-201L (Daikan Industries, Ltd). PTFE dispersions that may be used in the present invention include fullon AD-1, and AD-936 (Asahi-ICI Fluoropolymers Co., LTC), polyfullon D-1 or D-2 (Daikan Industries, Ltd), Teflon 30J (Mitsui- Dupont fluoro chemicals.Co., Ltd), FR302 (3F Co.), or JF4DC (Juseng fluoro chemicals Co., Ldt), including but not limited to. The PTFE powder or dispersion may be used alone or in combination of two or more kinds. PTFE is used at 47 to 53% by weight based on the total weight of the flame retardant aid, preferably at 48 to 52% by weight, more preferably at 49 to 51% by weight. Less than 47% by weight is less than flame retardant V-O, while more than 53% by weight suppresses the fluidity of the final resin.

Styrene-based monomers used in the present invention are styrene substituted or unsubstituted with one or more substituents selected from the group consisting of C _1-6 alkyl, C _1-6 alkoxy and halogen, for example, ortho-methylstyrene, meta-methyl Styrene, para-methylstyrene, dimethylstyrene, ethyl-styrene, para-tert-butylstyrene, methoxystyrene, fluorostyrene, monobromostyrene, dibromostyrene or tribromostyrene; Vinyl xylene; Or vinylnaphthalene, but is not limited thereto. The styrene monomers according to the present invention may be used alone or in combination of two or more kinds. It is preferable to use styrene substituted or unsubstituted with one or more substituents selected from the group consisting of C _1-6 alkyl, C _1-6 alkoxy and halogen as the styrene monomer according to the present invention.

Acrylic monomers used in the present invention include both substituted or unsubstituted (meth) acrylate derivatives. Specifically, the acrylic monomers of the present invention are (meth) acrylates which are unsubstituted or substituted with one or more substituents selected from the group consisting of C _1-20 alkyl, C _3-8 cycloalkyl, aryl and glycidyl, for example (Meth) acrylonitrile, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, amyl (meth) acrylate, hexyl (meth) acrylate, 2 Ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate or glycidyl ( Meth) acrylates; Maleimides unsubstituted or substituted with C _1-6 alkyl or aryl substituents, for example maleimide, N-methyl-maleimide or N-phenyl-maleimide; Or maleic acid, phthalic acid or itaconic acid. The acrylic monomers according to the present invention may be used alone or in combination of two or more kinds, and (meth) acrylonitrile is preferable.

  The amount of the acrylic monomer included in the coating layer is 7.5 to 11 parts by weight, preferably 8 to 10 parts by weight, more preferably 8 to 9 parts by weight based on 17.5 parts by weight of the styrene monomer. If the acrylic monomer is less than 8 parts by weight, the strength of the coating surface may be weakened, and if it is more than 11 parts by weight, the surface quality of the final resin may be degraded.

The flame retardant auxiliary agent of the present invention has a residual water content of 0.5% by weight or less, preferably 0.2 to 0.4% by weight, more preferably 0.1 to 0.3% by weight. A high 0.5% by weight may adversely affect the flame retardancy of the final resin.

The present invention also provides a method for preparing a flame retardant adjuvant comprising forming a coating layer comprising at least one monomer selected from the group consisting of styrene monomers and acrylic monomers in the presence of an anionic emulsifier and an initiator on the outside of polytetrafluoroethylene. It is about.

In the coating layer forming step, a first coating layer containing a styrene monomer is formed on the surface of polytetrafluoroethylene, and a second coating layer containing a copolymer of a styrene monomer and an acrylic monomer is formed on the surface of the first coating layer. It is preferable to form.

Preferably after the coating layer forming step further comprises the step of drying the remaining moisture content to 0.5% by weight or less, preferably 0.2 to 0.4% by weight, more preferably 0.1 to 0.3% by weight. The drying step can be carried out using methods known in the art such as, for example, hot air drying or vacuum drying.

The anionic emulsifier used in the present invention may be freely selected as long as it does not adversely affect the polymerization of the styrene and / or acrylic monomers. Commonly used anionic emulsifiers include, but are not limited to, Co436 (Rhodia chemicals Co., Ltd) or NPES (Cytec chemicals Co., Ltd). The amount of the anionic emulsifier can be freely selected as long as it does not adversely affect the reaction, it is preferable to use 0.3 to 0.5 parts by weight based on the total amount of the composition.

The initiator of the present invention may be used without limitation as long as it is used for polymerization of styrene-based and / or acrylic monomers. Initiators that can be used in the present invention include, but are not limited to, cumyl hydroperoxide, di-tert-butylperoxide, benzoyl peroxide, hydrogen peroxide, or potassium peroxide. In the present invention, one or more of the above initiators may be used depending on the reaction conditions. The amount of the initiator used in the present invention may be freely selected within the range generally used in the art in consideration of the amount of PTFE and the type / quantity of the monomer, and 0.15 to 0.25 parts by weight based on the total amount of the composition is used. It is preferable.

The present invention also provides a flame retardant resin composition comprising the flame retardant aid, flame retardant and polymer resin of the present invention. The polymer resin used in the present invention may be used without limitation as long as it is a polymer resin used in the art. Polymer resins that may be used in the present invention include, but are not limited to, for example, one or more resins selected from the group consisting of ABS, PC, HIPS, SAN, and PBT.

Representative flame retardants currently used include organic salt-based-flame retardants, halogenated aromatic flame retardants, aromatic phosphates and the like. The flame retardant that can be used in the present invention is not particularly limited and may be freely selected in consideration of the properties of the final resin. Organic salt-based-flame retardants which can be used in the present invention are sodium hexadecyl sulfate, potassium hexadecyl sulfate, potassium perfluorobutanesulfonate, dipotassium diphenylsulfone-3,3-disulfonate, potassium 2,4, 5-trichlorobenzenesulfonate, potassium diphenylphosphate, sodium diphenylphosphate, potassium bis (2,6-dibromo-4-cumylphenyl) phosphate, sodium bis (4-cumylphenyl) phosphate, potassium bis (4 Bromophenyl) phosphate, potassium bis (2,4-dibromophenyl) phosphate, potassium bis (2,4,6-tribromophenyl) phosphate, potassium bis (p-toluenesulfon) imide, sodium ra Urylsulfate or potassium laurylsulfate. Halogenated aromatic flame retardants that may be used in the present invention include tris (4-bromophenyl) phosphate, tris (2,4-dibromophenyl) phosphate or tris (2,4,6-tribromophenyl) phosphate However, the present invention is not limited thereto. Aromatic phosphates that may be used in the present invention include triphenyl phosphate, tris (2,6-xylyl) phosphate, resorcinol bis (dixylyl phosphate), 4,4'-biphenol bis (dixylyl phosphate) , Bisphenol A bis (dixylyl phosphate), or hydroquinone bis (dixylyl phosphate). In the present invention, at least one flame retardant may be used depending on the properties of the final resin.

Hereinafter, the present invention will be described using examples, which are only for understanding the present invention, and the scope of the present invention is not limited thereto in any sense.

EXAMPLE

Example 1 Preparation of Encapsulated PTFE

Preparation of Polytetrafluoroethylene

To prepare PTFE for use in preparing the flame retardant aid of the present invention, the PTFE dispersion was centrifuged at 600 rpm or higher to separate the PTFE solute from the solvent. The separated PTFE solute was used in the next step as a solid paste. PTFE contained 60 ± 1% by weight, the average particle size (Mm, median particle size) was 0.15 to 0.3 μm, and the specific gravity was about 1.5. The pH ranged from 9 to 10 and the specific gravity ranged from 10 to 20 mps.

Primary Encapsulation Step of PTFE

96.02 parts by weight of water and 61.83 parts by weight of PTFE paste were sequentially inserted into the reactor and stirred at room temperature. 3.21 parts by weight of Co436, an anionic emulsifier, was added and stirred at room temperature at about 120 rpm for 1 hour. Thereafter, 3.75 parts by weight of styrene monomer and tert-butylhydroperoxide as a water-soluble initiator were added to the mixture to form a styrene coating layer on the surface of PTFE.

Second Encapsulation Step of PTFE

After forming a layer made of styrene polymer on the PTFE surface, 13.75 parts by weight of styrene monomer and 7.50 parts by weight of acrylonitrile monomer were added dropwise at the same time. 1.5-3.0 parts by weight of cumene hydro-peroxide was added dropwise as a co-initiator. Thereafter, the temperature was raised to 90 ° C while stirring the reaction mixture at 80 rpm or more in the reactor, and left to stand for about 1 hour to mature the reaction. The reaction was spun for 30 minutes at 600-800 rpm with a bottom centrifuge and the product obtained as a paste at the bottom outlet. The paste was dried at 60 ° C. for about 2-3 hours using a hot air dryer to obtain a flame retardant aid in the form of particles. The residual moisture of the flame retardant aid was 0.5% by weight or less.

Examples 2-5 and Comparative Examples 1-4: PC / ABS resin containing a flame retardant adjuvant

The flame retardant aid obtained in Example 1 (hereinafter referred to as "encapsulated PTFE") and a conventional PTFE dispersion (particle size of about 0.4 ~ 0.6 ㎛) (hereinafter referred to as "unencapsulated PTFE") carried out in a composition as shown in Table 2 The resin composition of Examples 2-5 and Comparative Examples 1-4 was manufactured.

: PC / ABS resin (unit: parts by weight) PC ABS Thermal stabilizer ^a FR ^b Encapsulated PTFE Unencapsulated PTFE Example 2 40 60 0.15 10 0.5 - Example 3 50 50 0.15 10 0.5 - Example 4 60 40 0.15 10 0.5 - Example 5 80 20 0.15 10 0.5 - Comparative Example 1 40 60 0.15 10 - 0.5 Comparative Example 2 50 50 0.15 10 - 0.5 Comparative Example 3 60 40 0.15 10 - 0.5 Comparative Example 4 80 20 0.15 10 - 0.5

a: tris (2,4,6-tribromophenyl) phosphate

b: triphenyl phosphate (T.P.P)

Example 6 and Comparative Example 5: PC Resin With Flame Retardant Adjuvant

The resin compositions of Example 6 and Comparative Example 5 were prepared using the encapsulated PTFE and the non-encapsulated PTFE in the same composition as in Table 3.

PC resin (unit: parts by weight) PC FR ^a Encapsulated PTFE Unencapsulated PTFE Example 6 100.0 8.0 0.5 - Comparative Example 5 100.0 8.0 - 0.5

a: triphenyl phosphate (T.P.P)

Example 7 and Comparative Example 6: PC / ABS Resin With Flame Retardant Adjuvant

The resin compositions of Example 7 and Comparative Example 6 were prepared using the encapsulated PTFE and the non-encapsulated PTFE in the same composition as in Table 4.

: PC / ABS resin (unit: parts by weight) PC ABS SAN FR ^a Encapsulated PTFE Unencapsulated PTFE Example 7 60.0 30.0 10.0 7.0 0.5 - Comparative Example 6 60.0 30.0 10.0 7.0 - 0.5

a: triphenyl phosphate (T.P.P)

Example 8 and Comparative Example 7: PBT Resin With Flame Retardant Adjuvant

The resin compositions of Example 8 and Comparative Example 7 were prepared using the encapsulated PTFE and the non-encapsulated PTFE in the same composition as in Table 5.

: PBT resin (unit: parts by weight) PBT FR ^a SB ₂ O ₃ Encapsulated PTFE Unencapsulated PTFE Example 8 100.0 20.0 6.5 0.5 - Comparative Example 7 100.0 20.0 6.5 - 0.5

a: triphenyl phosphate (T.P.P)

Example 9 and Comparative Example 8: PBT Resin With Flame Retardant Adjuvant

The resin compositions of Example 9 and Comparative Example 8 were prepared using the encapsulated PTFE and the non-encapsulated PTFE in the same composition as in Table 6.

HIPS resin (unit: parts by weight) HIPS FR ^a SB ₂ O ₃ Encapsulated PTFE Unencapsulated PTFE Example 9 100.0 22.2 7.0 0.5 - Comparative Example 8 100.0 22.2 7.0 - 0.5

a: triphenyl phosphate (T.P.P)

Evaluation of physical properties of resins including flame retardant aids

The surface quality, tensile strength, elongation, flexural strength, flexural modulus, impact strength, and heat deflection temperature were tested using PC / ABS resins of Examples 2 to 5 and Comparative Examples 1 to 4. Surface quality was performed using a surface monitoring system and determined according to the following criteria:

(Circle): There is no blue spot or a dark spot, and a spray phenomenon is not observed.

(Triangle | delta): There is no black spot or a bright spot, but a trace spray phenomenon is visually observed.

X: Black spot or blue spot is observed.

The surface of PC / ABS resin of Comparative Example 1 and Example 2 was photographed and shown in FIGS. 1A to 2B. Tensile strength and elongation were performed in accordance with ASTM D638, flexural strength and flexural modulus were performed in accordance with ASTM D790, impact strength was performed in accordance with ASTM D256, and thermal deformation strength was performed in accordance with ASTM D648. Each test was conducted on 10 samples and the results are shown in Table 7.

Physical property evaluation Surface quality The tensile strength Elongation Flexural strength Flexural modulus Impact strength Heat deflection temperature Example 2 ○ 580 55 880 23000 40 110 Example 3 ○ 590 55 900 24000 50 110 Example 4 ○ 600 56 920 24000 50 110 Example 5 ○ 610 56 940 25000 60 111 Comparative Example 1 △ 580 55 900 23000 40 110 Comparative Example 2 △ 585 55 900 24000 50 110 Comparative Example 3 △ 605 55 905 24000 50 110 Comparative Example 4 △ 608 56 915 25000 60 111

As shown in the table and drawing, the encapsulated PTFE-containing resin is not found in the agglomeration of the PTFE on the surface, the resin containing the non-encapsulated PTFE it can be seen that the PTFE on the surface of the agglomerate. Thus, it can be seen that PC / ABS containing encapsulated PTFE of the present invention has superior surface quality compared to PC / ABSC containing unencapsulated PTFE.

Evaluation of flame retardancy of resin including flame retardant adjuvant

Using the resin composition of Examples 6-9 and Comparative Examples 5-8, the resin layer which is 1/16 inch of thickness was manufactured. Appropriate ratio, cotton burning, burning rate and flame retardancy of the resin layer were evaluated according to the flame retardancy evaluation standard UL94. Each test was carried out on 10 samples, the results of which are shown in Table 8.

: Flame Retardant Evaluation Proper cost Cotton burning Burning rate (sec) Flame retardancy Example 6 0/10 0/10 6 V-0 Example 7 0/10 0/10 3 V-0 Example 8 0/10 0/10 4 V-0 Example 9 0/10 0/10 3 V-0 Comparative Example 5 0/10 0/10 20 V-0 Comparative Example 6 0/10 0/10 19 V-0 Comparative Example 7 0/10 0/10 20 V-0 Comparative Example 8 0/10 0/10 19 V-0

As shown in the table, it can be seen that the resin containing the flame retardant aid of the present invention has the same or more flame retardancy as compared with the resin containing the conventional flame retardant aid, and in particular, the combustion rate is improved.

The present invention has the effect of improving the flame retardancy of the polymer resin, improve the injection surface quality of the polymer resin, can be stored for a long time, and easy to handle PTFE flame retardant auxiliary.

Claims (14)

Polytetrafluoroethylene; A first coating layer formed on the outside of the polytetrafluoroethylene; And A second coating layer formed on the surface of the first coating layer; Here, the first coating layer contains a styrene-based monomer, the second coating layer is a flame-retardant auxiliary containing an acrylic monomer. delete The flame retardant aid according to claim 1, wherein the second coating layer comprises a copolymer of a styrene monomer and an acrylic monomer. The flame retardant aid according to claim 1 or 3, wherein the particle size of the flame retardant aid is 0.2 to 0.6 mu m. The flame retardant aid according to claim 1 or 3, wherein the polytetrafluoroethylene is 47 to 53% by weight based on the total weight of the flame retardant aid. The flame retardant aid according to claim 1 or 3, wherein the styrenic monomer is styrene unsubstituted or substituted with one or more substituents selected from the group consisting of C _1-6 alkyl, C _1-6 alkoxy and halogen. The flame-retardant adjuvant of Claim 1 or 3 whose acryl-type monomer is (meth) acrylonitrile. The flame retardant aid of claim 1 or 3, wherein the amount of the acrylic monomer included in the coating layer is 7.5 to 11 parts by weight based on 17.5 parts by weight of the styrene monomer. The flame retardant aid according to claim 1 or 3, wherein the residual moisture content is 0.5% by weight or less. In the presence of an anionic emulsifier and initiator, Forming a first coating layer on the surface of the polytetrafluoroethylene; And Forming a second coating layer on the surface of the first coating layer; Here, the first coating layer contains a styrene-based monomer, the second coating layer contains a copolymer of a styrene-based monomer and an acrylic monomer, a method for producing a flame retardant aid. delete The method of claim 10, further comprising drying the residual moisture content to 0.5 wt% or less after the coating layer forming step. The flame retardant aid of claim 1; Flame retardant; And a resin; Here, the resin is flame retardant resin composition, characterized in that selected from the group consisting of ABS, PC, HIPS, SAN, and PBT. The composition of claim 13 wherein the flame retardant is at least one selected from the group consisting of organic salt-based-flame retardants, halogenated aromatic flame retardants and aromatic phosphates.

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