Patent Application
20250154343
The present disclosure relates to a novel phosphorus (P)-based flame retardant and to a thermoplastic resin composition capable of providing improved mechanical properties, while exhibiting excellent flame retardancy by including the phosphorus-based flame retardant, even if an amount used is reduced compared to conventional flame retardants.
Thermoplastic polyester resins are excellent in terms of chemical resistance, mechanical strength, heat resistance and electrical properties, and are thus widely used in housings and connectors of electronic, electrical and automotive parts. Since such polyester resins generally have a flammable property, it was used with a halogen-based flame retardant or an antimony-based flame-retardant auxiliary agent to be applied to a field requiring flame retardancy. However, the halogen-based flame retardant or the antimony-based flame-retardant auxiliary agent not only generates a large amount of toxic halogen gas in case of fire, but also has a problem in that an excessive amount of the flame retardant should be used in order to exhibit desired flame retarding effects.
In order to solve the above problems, a method of imparting flame retardancy to a polyester resin using a non-halogen flame retardant such as an organic phosphinate metal salt flame retardant, an organo phosphinic acid metal salt flame retardant, and a melamine polyphosphate has been proposed. However, when the flame retardancy is imparted by using the above-described compounds, there was a problem that the physical properties of a final resin may be excessively degraded since an excessive amount of a flame retardant was used.
Korean Patent No. 10-2285778
Embodiments of the present disclosure are directed to an environmentally friendly phosphorus (P)-based flame retardant which may realize excellent flame retardancy even if an amount used is reduced compared to a conventional flame retardant.
Embodiments of the present disclosure are also directed to a thermoplastic resin composition including the above-described phosphorus-based flame retardant and a molded article using the thermoplastic resin composition.
Other objectives and advantages of the present disclosure may be more clearly explained by the following detailed description and claims.
According to an embodiment, a phosphorus-based flame retardant is represented by the following Chemical Formula 1:
According to an embodiment, a phosphorus-based flame retardant is represented by the following Chemical Formula 2:
According to an embodiment, a thermoplastic resin composition includes a thermoplastic resin; and one or more phosphorus-based flame retardants selected from the phosphorus-based flame retardant represented by Chemical Formula 1 and the phosphorus-based flame retardant represented by Chemical Formula 2.
In some embodiments, the phosphorus-based flame retardant may be included in an amount in a range from 0.1 to 50 parts by weight with respect to 100 parts by weight of the thermoplastic resin composition.
In some embodiments, the thermoplastic resin composition may include at least one of a polyester resin or a polyamide resin.
In some embodiments, the thermoplastic resin may be polybutylene terephthalate (PBT).
According to an embodiment, a molded article is formed from the thermoplastic resin composition.
The novel phosphorus (P)-based flame retardant according to one or more embodiments of the present disclosure may be used as a flame retardant or a flame retardant additive of a thermoplastic resin composition, may exhibit flame retardancy equivalent to or more excellent than a conventional phosphorus-based flame retardant even if an amount used is reduced, and may be significantly improved in terms of mechanical properties such as tensile strength and impact strength.
The effect according to the present disclosure is not limited by the descriptions exemplified above, and more various effects are included in the present specification.
Hereinafter, the present disclosure will be described in detail.
All terms (including technical and scientific terms) used herein may be used in the meaning commonly understood by those of ordinary skill in the art to which the present disclosure pertains, unless otherwise defined. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless clearly defined in particular.
Throughout this specification, when a part “includes” a certain element, it is an open-ended term that includes the possibility of further including other elements rather than excluding other elements, unless otherwise stated.
As used herein, “preferred” and “preferably” refer to embodiments of the disclosure that may provide certain advantages under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred examples does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the disclosure.
An example of the present disclosure is a compound represented by Chemical Formula 1 or 2 described above, which may be added to a thermoplastic resin composition to be used as a flame retardant or a flame retardant additive (auxiliary agent).
Specifically, the compound represented by Chemical Formula 1 may be a compound including at least one substituent capable of coordinate bonding with M, and the compound represented by Chemical Formula 2 may be a compound including a common hydrocarbon-based condensed or fused ring formed by R3 and R4 bonded with each other.
For a specific example of the compound represented by Chemical Formula 1 or 2, R1 to R3 may be the same as or different from each other, and may each independently be one or more selected from a hydroxyl group, a C1 to C10 alkyl group, a C2 to C10 alkenyl group, a C6 to C20 aryl group, and a heteroaryl group having 5 to 20 nuclear atoms. More specifically, R1 to R3 may each independently be selected from a hydroxyl group, a C1 to C10 alkyl group, and a C6 to C20 aryl group.
R4 may have two embodiments depending on whether or not a condensed or fused ring with R3 is formed.
In a specific example, in Chemical Formula 1 that does not form a condensed or fused ring, R4 may be one or more selected from a C1 to C10 alkyl group, a C2 to C10 alkenyl group, and a C6 to C20 aryl group, where the alkyl group, the alkenyl group, and/or the aryl group of R4 may each include at least one or more substituents capable of coordinate bonding with the following M.
In such a case, as the substituent capable of coordinate bonding with M, a common substituent having a lone pair of electrons that does not participate in bonding may be used without limitation. For example, the substituent capable of coordinate bonding with M may be selected from a hydroxyl group (—OH), a carboxyl group (—COOH), and an amine group (—NR11R12). More specifically, R4 that does not form the condensed ring may be selected from a C1 to C10 alkyl group and a C6 to C20 aryl group substituted with one or more coordinate-bondable substituents.
In another specific example, in the compound of Chemical Formula 2 that forms a condensed or fused ring, R4 is not particularly limited in terms of the type and number of carbon atoms of the substituent, the form of the condensed ring, and the like, as long as it may be bonded with the aforementioned R3 to form a common monocyclic or polycyclic condensed ring known in the art. For example, it may be the same as or different from defined for R4 in Chemical Formula 1 described above.
M may be selected from Al, Mg, Ca, Sb, Sn, Ge, Ti, Zn, Fe, Ni, Zr, Ce, Bi, Sr, Mn, Li, Na, and K, or may be an ammonium ion.
In addition, m, n, and x may each be an integer in a range from 1 to 5.
According to the present disclosure, the compound represented by Chemical Formula 1 or 2 may be a salt including at least two or more heterogeneous phosphoric acid-based moieties having different structures and functions. When the compound represented by Chemical Formula 1 or 2 is used as a flame retardant or flame retardant additive for a thermoplastic resin, it may exhibit flame retardancy equivalent to or more excellent than the conventional phosphoric acid-based flame retardant including one phosphoric acid-based moiety or the same phosphoric acid-based moieties, even if a small amount is used than an amount of the conventional phosphoric acid-based flame retardant, and may be significantly improved in terms of mechanical properties. In addition, since the thermoplastic resin may be further used as much as the reduced amount of the flame retardant used, the physical stability and mechanical properties of a final thermoplastic resin may be improved by improving the degree of polymerization.
For example, the compound represented by Chemical Formula 1 may be more specified into any one of the following Chemical Formulas 1a to 1f according to the type of the substituent capable of coordinate bonding introduced to R4 and/or the type of the substituent of R3.
In Chemical Formulas 1a to 1f,
The compounds represented by Chemical Formulas 1a to 1f described above may be more specified into any one of Chemical Formulas 3a to 31 exemplified below according to the form of a coordinate bond with M. However, it is not limited by those exemplified below.
In Chemical Formulas 3a to 3l,
For example, the compounds represented by Formulas 3a to 3f exemplify forms in which the metal (M) is +3, and the compounds represented by Formulas 3g to 3i are exemplify forms in which the metal (M) is +2, and the compounds represented by Chemical Formulas 3k to 3l exemplify the form in which the metal (M) is +4. However, it is not limited by those above, and is not particularly limited to the type of metal, bonding position, or chemical structure, as long as it can satisfy the charge balance of the metal to be coordinated. It is also within the scope of the present disclosure to include possible common metals capable of forming coordination bond.
In another embodiment, the compound represented by Chemical Formula 2 may be more specified into the following Chemical Formula 2a or 2b according to the type of a condensed ring or fused ring formed by a bond between R3 and R4.
In Chemical Formula 2a or 2b,
In one example, rings A and B may be a monocyclic or polycyclic, heteroalicyclic or a monocyclic or polycyclic heteroaromatic ring, and may specifically be a heteroalicyclic ring having 3 to 10 nuclear atoms or a heteroaromatic ring having 5 to 10 nuclear atoms. In such a case, the heteroatom may include phosphorus (P), and may further include at least one or more common heteroatoms (e.g., X1, X2) known in the art.
X1 and X2 may be the same as or different from each other, and may each independently be CR21R22 or NR23, where at least one of X1 and X2 may be N. In such a case, when ring B is a heteroaromatic ring, any one of R21 and R22 may be unbonded.
R21 to R23 may be the same as or different from each other, and may each independently be selected from hydrogen, a C1 to C40 alkyl group and a C6 to C60 aryl group, and specifically from hydrogen and a C1 to C10 alkyl group.
Ring A, ring B, the alkyl group and the aryl group of R21 to R23 may each independently be unsubstituted or substituted with one or more substituents selected from deuterium (D), halogen, a cyano group, a nitro group, a C1 to C40 alkyl group, a C6 to C60 aryl group, and a heteroaryl group having 5 to 60 nuclear atoms, and
The compound represented by Chemical Formula 2a or 2b described above may be more specified into Chemical Formula 4a to 4d exemplified below depending on the form of a coordinate bond with M. However, it is not limited by those exemplified below.
In Chemical Formula 4a to 4d,
For example, the compounds represented by Formulas 4a or 4b exemplify forms in which the metal (M) is +2, and the compounds represented by Formulas 4c or 4d are exemplify forms in which the metal (M) is +3. However, it is not limited by those above, and is not particularly limited to the type of metal, bonding position, or chemical structure, as long as it can satisfy the charge balance of the metal to be coordinated. It is also within the scope of the present disclosure to include possible common metals capable of forming coordination bond.
The phosphorus-based flame retardant compound represented by Chemical Formula 1 or 2 of the present disclosure described above may be more specified into compounds exemplified below. However, the compound represented by Chemical Formula 1 or 2 of the present disclosure is not limited by those exemplified below.
As used herein, “alkyl” may refer to a monovalent substituent derived from a linear or branched chain saturated hydrocarbon having 1 to 40 carbon atoms. Examples of such alkyl may include, but are not limited to, methyl, ethyl, propyl, isobutyl, sec-butyl, pentyl, iso-amyl, hexyl or the like.
As used herein, “alkenyl” may refer to a monovalent substituent derived from a linear or branched chain unsaturated hydrocarbon having 2 to 40 carbon atoms, having at least one carbon-carbon double bond. Examples of such alkenyl may include, but are not limited to, vinyl, allyl, isopropenyl, 2-butenyl or the like.
As used herein, “alkynyl” may refer to a monovalent substituent derived from a linear or branched chain unsaturated hydrocarbon having 2 to 40 carbon atoms, having at least one carbon-carbon triple bond. Examples of such alkynyl may include, but are not limited to, ethynyl, 2-propynyl or the like.
As used herein, “aryl” may refer to a monovalent substituent derived from an aromatic hydrocarbon having 6 to 60 carbon atoms which is in a structure with a single ring or two or more rings combined with each other. In addition, a form in which two or more rings are pendant (e.g., simply attached) to or fused with each other may also be included. Examples of such aryl may include, but are not limited to, phenyl, naphthyl, phenanthryl, anthryl or the like.
As used herein, “heteroaryl” may refer to a monovalent substituent derived from a monoheterocyclic or polyheterocyclic aromatic hydrocarbon having 5 to 40 nuclear atoms. In such a case, one or more carbons in the ring, preferably one to three carbons, are substituted with a heteroatom such as N, O, S or Se. In addition, a form in which two or more rings are pendant to or fused with each other may be included and a form fused with an aryl group may be included. Examples of such heteroaryl may include, but are not limited to, a 6-membered monocyclic ring including, for example, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl and triazinyl; a polycyclic ring including, for example, phenoxathiinyl, indolinzinyl, indolyl, purinyl, quinolyl, benzothiazole, and carbazolyl; 2-furanyl; N-imidazolyl; 2-isoxazolyl; 2-pyridinyl; 2-pyrimidinyl or the like.
As used herein, “cycloalkyl” may refer to a monovalent substituent derived from a monocyclic or polycyclic non-aromatic hydrocarbon having 3 to 40 carbon atoms. Examples of such cycloalkyl may include, but are not limited to, cyclopropyl, cyclopentyl, cyclohexyl, norbornyl, adamantine or the like.
As used herein, “heterocycloalkyl” may refer to a monovalent substituent derived from a non-aromatic hydrocarbon having 3 to 40 nuclear atoms, where one or more carbons in the ring, preferably one to three carbons, are substituted with a heteroatom such as N, O, S or Se. Examples of such heterocycloalkyl may include, but are not limited to, morpholine, piperazine or the like.
Another example of the present disclosure is a thermoplastic resin composition including the above-described phosphorus (P)-based flame retardant and a thermoplastic resin.
In such a case, since the phosphorus (P)-based flame retardant is the same as that described above, the description thereof will be omitted.
In the thermoplastic resin composition according to the present disclosure, a content of the phosphorus-based flame retardant is not particularly limited, and may be appropriately adjusted within a conventional content range known in the art. For example, the phosphorus-based flame retardant may be used in an amount in a range from 0.1 to 50 parts by weight, specifically in a range from 1 to 40 parts by weight, and more specifically in a range from 3 to 30 parts by weight, with respect to 100 parts by weight of the thermoplastic resin composition. When it has the above content range, it is possible to improve the flame retardant properties of the thermoplastic resin, such as polyester resins, polyamide resins, and the like. In particular, unlike the conventional flame retardant in which mechanical properties of the final thermoplastic resin product are necessarily degraded, the thermoplastic resin product including the phosphorus-based flame retardant according to the present disclosure may maintain mechanical properties, while exhibiting excellent flame retardant effect.
In the present disclosure, common thermoplastic resins known in the art may be used without limitation.
Non-limiting examples of the applicable thermoplastic resin may include: a resin alone selected from: polyester resin, polyamide (PA)-based resin, polystyrene (PS) resin, acrylonitrile-butadiene-styrene (ABS) copolymer resin, rubber-modified high-impact polystyrene (HIPS) resin, acrylonitrile-styrene (SAN) copolymer resin, polycarbonate (PC) resin, polyethylene (PE) resin, polypropylene (PP) resin, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polymethyl methacrylate (PMMA), and polyamide (PA)-based resin, or a copolymer of the resins, an alloy of the resins, and the like. Specifically, the thermoplastic resin may use at least one of a polyester resin or a polyamide (PA)-based resin and may preferably be polybutylene terephthalate (PBT).
A content of the thermoplastic resin is not particularly limited, and may be appropriately adjusted within a conventional content range known in the art. In the present disclosure, the thermoplastic resin may be of a remaining amount to match 100 parts by weight of the thermoplastic resin composition excluding the phosphorus-based flame retardant described above. For example, the thermoplastic resin may be used in an amount in a range from 10 to 85 parts by weight, specifically in a range from 10 to 70 parts by weight, and more specifically in a range from 10 to 60 parts by weight, with respect to 100 parts by weight of the thermoplastic resin composition. When it has the above-described content range, excellent physical properties of the thermoplastic resin itself may be exhibited.
The thermoplastic resin composition according to the present disclosure may further include a common resin known in the art other than the aforementioned thermoplastic resin. For example, polyolefin resins, vinyl-based resins, (meth)acrylic resins, imide-based resins, polystyrene-based resins, thermosetting resins such as epoxy resins, cellulose resins, polyetheretherketone resins, fluororesins, polycarbonate resins, and the like may be included.
In addition, in the present disclosure, within the range that does not impair the effect of the disclosure, an additive suitable for the intended use or effect may be further included. Examples of applicable additives may include, but not limited to, one or more selected from: fillers, colorants, pigments, dyes, dispersants, plasticizers, antioxidants, curing agents, flame retardants, flame retardant auxiliary agents, heat stabilizers, light stabilizers, ultraviolet absorbers, antistatic agents, leveling agents, surfactants, lubricants, release agents, nucleating agents, antifrictions, compatibilizers, char formers, impact modifiers, anti-drip agents, and chain extenders. A content of the additive is not particularly limited and may be appropriately adjusted within a conventional content range known in the art, for example, in a range from 0.1 to 20 parts by weight with respect to 100 parts by weight of the thermoplastic resin composition.
The thermoplastic resin composition according to the present disclosure may be prepared according to a conventional method known in the art, for example, after appropriately mixing the thermoplastic resin, the phosphorus-based flame retardant, other resins or additives, and the like, the mixture may be melt-kneaded using Banbury mixer, kneader, uniaxial or double-axial extruder and the like. In addition, the composition may be melt-extruded according to a conventional method to prepare pellets and the pellets may be used to mold various products.
Another example of the present disclosure is a molded article including the thermoplastic resin composition described above.
A shape of the molded article may be appropriately changed according to the usage, and may be, for example, a film shape, a plate shape, a fibrous shape, and the like. However, the present disclosure is not particularly limited thereto. Specific examples of the molded article may include a film, a sheet, a bottle, a liquid crystal display, a hologram, a filter, a dielectric film, an insulating material for an electric wire, an insulating tape, a fiber-reinforced composite, other injection-molded articles, and the like. In addition, it may be applicable to electric and electronic products such as housings of TVs, computers, audio systems, air conditioners and office automation equipment.
The molded article according to the present disclosure may be manufactured according to a conventional method known in the art, for example, a mixture including the thermoplastic resin composition, the phosphorus-based flame retardant, other resins or additives, and the like may be subjected to press molding, foam molding, injection molding, extrusion molding, and punching molding to obtain the molded article. In such a case, the mixture may be obtained in a manner where after appropriately mixing the thermoplastic resin composition, the phosphorus-based flame retardant, other resins or additives, and the like, the mixture may be melt-kneaded using Banbury mixer, kneader, uniaxial or double-axial extruder and the like.
In a specific example, the molded article may be a film.
The film may be manufactured by a conventional method known in the art, such as inflation molding, extrusion molding such as melt extrusion molding, and a solution casting method. The manufactured film may be a single-layer film made of the thermoplastic resin composition, or a single-layer or multi-layer film including different materials.
In another specific example, the molded article may be a fiber.
The fiber may be manufactured by conventional methods known in the art, such as melt spinning, solution spinning, and the like. The manufactured fiber may be in the form of being made of the thermoplastic resin composition or mixed with a heterogeneous resin.
The thermoplastic resin composition and the molded article according to the present disclosure described above not only have excellent flame retardancy but also have improved physical stability and enhanced mechanical properties of a final thermoplastic resin due to the phosphorus (P)-based flame retardant, even if an amount used is reduced compared to conventional flame retardants, and thus they may be usefully applicable in the manufacture of molded articles such as housings and connectors for electronic/electrical and automobile parts. However, it is not limited to the above-described usage, and it is applicable to various technical fields and processes to which the polyester resin, the polyamide resin, and the like are conventionally applied.
Hereinafter, the present disclosure will be described in detail through examples. However, the following examples are only provided to illustrate the present disclosure, and the present disclosure is not limited by the following examples.
After adding 100 g of 2-hydroxy-1, 3-dimethyl-1,3,2-bisazaphosphine oxide, 162.7 g of diethyl phosphinic acid, and 320 g of aluminum sulfate to a reactor, 7,000 ml of water was further added thereto, and then a temperature was raised to 110° C., followed by stirring for 12 hours. When the reaction was completed, the temperature was lowered to room temperature, and a white solid was filtered and washed with 3,000 ml of water and 3,000 ml of ethanol. The washed white solid was vacuum-dried at 120° C. for 24 hours to prepare a phosphorus-based flame retardant additive 1 (yield: 87%) represented by the following Chemical Formula 5a.
MS: [M+H]+=419.1
A phosphorus-based flame retardant additive 2 (yield: 92%) represented by the following Chemical Formula 5b was prepared in the same manner as in Synthesis Example 1, except that 100 g of 2-carboxyethylphenyl phosphinic acid instead of 2-hydroxy-1,3-dimethyl-1,3,2-bisazaphosphine oxide, 57 g of diethyl phosphinic acid, and 134.5 g of aluminum sulfate were used.
MS: [M+H]+=423.1
A phosphorus-based flame retardant additive 3 (yield: 78%) represented by the following Chemical Formula 5c was prepared in the same manner as in Synthesis Example 1, except that 125.3 g of dimethyl phosphinic acid instead of 2-hydroxy-1,3-dimethyl-1,3,2-bisazaphosphine oxide and 192 g of aluminum sulfate were used.
MS: [M+H]+=363.1
A phosphorus-based flame retardant additive 4 (yield: 87%) represented by the following Chemical Formula 5d was prepared in the same manner as in Synthesis Example 1, except that 100 g of 2-carboxyethylphenyl phosphinic acid, 44 g of dimethyl phosphinic acid and 134.5 g of aluminum sulfate were used.
MS: [M+H]+=333.0
A phosphorus-based flame retardant additive 5 (yield: 79%) represented by the following Chemical Formula 5e was prepared in the same manner as in Synthesis Example 1, except that 100 g of 1,3-diethyl-2-hydroxy-1,3,2-diaza phosphine oxide, 245 g of diphenyl phosphinic acid and 161.6 g of aluminum sulfate were used.
MS: [M+H]+=639.1
A phosphorus-based flame retardant additive 6 (yield: 82%) represented by the following Chemical Formula 5f was prepared in the same manner as in Synthesis Example 1, except that 100 g of 2-carboxyethylphenyl phosphinic acid, 228 g of diethyl phosphinic acid and 160 g of aluminum sulfate were used.
MS: [M+H]+=750.2
A phosphorus-based flame retardant additive 7 (yield: 75%) represented by the following Chemical Formula 5g was prepared in the same manner as in Synthesis Example 1, except that 100 g of phosphonoacetic acid, 261.2 g of diethyl phosphinic acid and 243.9 g of aluminum sulfate were used.
MS: [M+H]+=555.1
After adding 100 g of 2-hydroxy-1,3-dimethyl-1,3,2-bisazaphosphine oxide, 81.37 g of diethyl phosphinic acid, and 107.6 g of zinc sulfate to a reactor, 2,000 ml of water was further added thereto, and then a temperature was raised to 110° C., followed by stirring for 12 hours. When the reaction was completed, the temperature was lowered to room temperature, and a white solid was filtered and washed with 3,000 ml of water and 3,000 ml of ethanol. The washed white solid was vacuum-dried at 120° C. for 24 hours to prepare a phosphorus-based flame retardant additive 8 (yield: 71%) represented by the following Chemical Formula 5h.
MS: [M+H]+=335.0
A phosphorus-based flame retardant additive 9 (yield: 73%) represented by the following Chemical Formula 5i was prepared in the same manner as in Synthesis Example 1, except that 100 g of 2-carboxyethylphenyl phosphinic acid, 114 g of diethyl phosphinic acid and 150.8 g of zinc sulfate were used.
MS: [M+H]+=585.0
Specific details of components used in (composition) Examples 1 to 8 are shown in Table 1 below. According to the composition of Table 2 below, the thermoplastic resin and the phosphorus-based flame retardant were mixed with a mixer for 5 to 20 minutes, then added to an extruder, and melted and extruded under conditions of a cylinder temperature of 240° C. and a stirring speed of 200 rpm to prepare pellets. The prepared pellets were dried at 90° C. for one day, and then injected at 240° C. to prepare a specimen for measuring physical properties.
A specimen for measuring physical properties of Comparative Example 1 was prepared in the same manner as in Example 1, except that metal phosphinate (manufacturer: Clariant, Exolit OP1240) was used instead of the phosphorus-based flame retardant prepared in Synthesis Examples 1 to 7.
The physical properties of the specimens prepared in Examples 1 to 8 and Comparative Example 1 were evaluated as follows, and the results are shown in Table 2 below.
(1) Flame retardancy ratings: flame retardancy was measured according to the UL94 V test method. In this case, a specimen having a thickness of 0.8 mm was used.
(2) Tensile strength: measured according to the evaluation method specified in ASTM D638.
(3) Impact strength: measured according to the evaluation method specified in ASTM D256.
As shown in Table 2, it was appreciated that the thermoplastic resin compositions of Examples 1 to 8 including the phosphorus-based flame retardant according to the present disclosure exhibited a flame retardancy equal to or greater than that of Comparative Example 1 not including the phosphorus-based flame retardant, and also had significantly improved mechanical properties such as tensile strength and impact strength. In particular, despite including a small amount of the phosphorus-based flame retardant as compared to Comparative Example 1, the thermoplastic resin composition of Example 6 exhibited comparable flame retardancy, as well as a tensile strength improved by about 50 kgf/cm2 or more and an impact strength improved by about 0.5 kgf·cm/cm or more.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0138496 | Oct 2021 | KR | national |
| 10-2022-0133543 | Oct 2022 | KR | national |
This application is a US national phase of international application No. PCT/KR2022/015842 filed on Oct. 18, 2022, and claims priority to Korean Patent Application No. 10-2021-0138496 filed on Oct. 18, 2021 and Korean Patent Application No. 10-2022-0133543 filed on Oct. 17, 2022, and all the benefits accruing therefrom under 35 U.S.C. § 119, the disclosures of which in their entirety are herein incorporated by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2022/015842 | 10/18/2022 | WO |
