Water-based dispersion type flame retardant

Abstract

The present invention provides a water-based dispersion-type flame retardant that exhibits flame retardant effects equivalent to or better than those of both DBDPE and antimony trioxide, even when using small amounts or none of both compounds. [Solution] The present invention relates to an aqueous dispersion type flame retardant comprising a flame retardant component dispersed in an aqueous solvent, characterized in that (1) the flame retardant component comprises (1a) a metal salt of dialkylphosphinic acid and (1b) a brominated flame retardant component having a melting point of 150°C or less (excluding the metal salt), and (2) the ratio of the metal salt to the brominated flame retardant component is such that, with the total of both being 100% by weight, the ratio of metal salt:brominated flame retardant component = 90% by weight:10% by weight to 40% by weight:60% by weight.

Description

Technical Field

[0001] The present invention relates to a novel aqueous dispersion type flame retardant.

Background Art

[0002] As a form of flame retardant, there is an aqueous dispersion type in which a flame retardant component is dispersed in an aqueous solvent, and it is preferably adopted from the viewpoints of, for example, handleability, safety, and working environment (for example, Patent Documents 1 and 2).

[0003] In addition, as a flame retardant applied to a flame retardant resin composition, currently, a flame retardant in which decabromodiphenyl ethane (DBDPE) and antimony oxide are used in combination is widely used from the viewpoints of flame retardancy and cost.

[0004] However, antimony oxide largely depends on imports from foreign countries, and its supply stability is poor due to fluctuations in import prices, supply amounts, etc. In addition, in Japan, it is listed in the Poisonous and Deleterious Substances Control Law (poisonous substances), so it is difficult to handle in terms of laws and regulations when used. In particular, antimony trioxide (Sb2O3) with the highest flame retardant effect is listed as a "Class 2 Controlled Substance" and a "Specially Controlled Substance" of specified chemical substances under the Industrial Safety and Health Law, so it is necessary to conduct workplace environment measurements, health examinations, etc.

[0005] Regarding DBDPE as well, there are movements such as legal use restrictions in various countries around the world. Ahead of other countries, Canada has concluded that DBDPE may have an adverse impact on the domestic environment and its biodiversity and is toxic, and has announced a restriction plan. In Europe, listing as a Substance of Very High Concern (SVHC) is being considered, and it is becoming difficult to use legally. Therefore, in the future, it is expected that suppliers will also adjust production volumes or may discontinue sales, so DBDPE may also become unstable in terms of supply in the future.

[0006] Therefore, recently, the development of agents that do not use DBDPE or antimony oxide has been underway (Patent Documents 3 to 6). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] International release WO2015 / 37385 [Patent Document 2] Japanese Patent Publication No. 2021-130801 [Patent Document 3] Japanese Patent Publication No. 2012-167411 [Patent Document 4] Special Publication No. 2000-508365 [Patent Document 5] Patent No. 6077465 [Patent Document 6] Special Publication 2020-512457 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] As described above, particularly from the perspective of environmental impact and impact on human health, there is a need for the development of a water-based dispersion type flame retardant that can provide a high degree of flame retardancy without relying on both DBDPE and antimony trioxide compounds.

[0009] Furthermore, even in the prior art described above, there is still room for further improvement when comparing the flame retardancy of the two compounds mentioned above.

[0010] Therefore, the main object of the present invention is to provide a water-based dispersion type flame retardant that can exhibit flame retardant effects equivalent to or better than those of both DBDPE and antimony trioxide, even when using small amounts or none of both compounds. [Means for solving the problem]

[0011] In light of the problems of the prior art, the inventors conducted extensive research and, as a result, discovered that the above objective can be achieved by adopting a composition containing a specific flame-retardant component, thus completing the present invention.

[0012] In other words, the present invention relates to the following aqueous dispersion-type flame retardant. 1. An aqueous dispersion type flame retardant comprising a flame retardant component dispersed in an aqueous solvent, (1) The flame retardant component comprises (1a) a metal salt of dialkylphosphinic acid and (1b) a brominated flame retardant component having a melting point of 150°C or less (excluding the metal salt), (2) The ratio of the metal salt to the brominated flame retardant component is such that, with the total of both components being 100% by weight, the ratio of metal salt to brominated flame retardant component is 90% by weight:10% by weight to 40% by weight:60% by weight. A water-based dispersion-type flame retardant characterized by the following features. 2. The aqueous dispersion type flame retardant according to item 1, further comprising a resin binder. 3. The aqueous dispersion type flame retardant according to item 1, further comprising at least one anionic surfactant and a nonionic surfactant. 4. The aqueous dispersion type flame retardant according to item 1, wherein the average particle size of the dispersed particles in the aqueous dispersion type flame retardant is 0.1 to 20 μm. 5. The aqueous dispersion type flame retardant according to item 1, wherein the total content of decabromodiphenylethane and antimony oxide is 0 to 1% by weight. 6. Flame-retardant fibers containing fibers and flame-retardant components, (1) The flame retardant component includes a metal salt of dialkylphosphinic acid and a brominated flame retardant component (excluding the metal salt), (2) The ratio of the metal salt to the brominated flame retardant component is such that, with the total of both components being 100% by weight, the ratio of metal salt to brominated flame retardant component is 90% by weight:10% by weight to 40% by weight:60% by weight. A flame-retardant fiber characterized by the following properties. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a water-based dispersion type flame retardant that can exhibit flame retardant effects equivalent to or better than those of both DBDPE and antimony trioxide, even when using small amounts or none of both compounds.

[0014] That is, the flame retardant of the present invention contains a metal salt of dialkylphosphinic acid and a bromine-based flame retardant component having a melting point of 150°C or lower in a specific ratio. Therefore, excellent flame retardancy can be obtained without relying on both compounds of DBDPE and antimony trioxide.

[0015] In addition, when a large amount of a low-melting-point bromine-based flame retardant that melts under the temperature conditions of the drying process is generally used, bleeding out (blooming) generally occurs on the surface of the coating film, and there is a tendency for the coated surface to turn white or develop chalk marks over time. However, these problems can also be effectively suppressed by the flame retardant of the present invention.

[0016] The flame retardant of the present invention having such characteristics is effective as a flame retardant for processing various products (fibers, sheets, films, etc.). In particular, it can be more preferably used as a flame retardant for fibers (especially for post-processing). Among other things, for polyester fibers, a higher flame retardant effect can be obtained.

[0017] As a result, for example, it is possible to avoid the use of DBDPE, which is a chemical substance newly listed as a candidate for restrictions on manufacturing, use, sales, and import in the Canadian Ministry of the Environment (revision of the "Regulations on Prohibiting Specific Hazardous Substances") in 2022, etc., and the movement of regulations is accelerating. In addition, it is also possible to avoid the use of antimony trioxide, which is an external medicine for pharmaceuticals and also a specific chemical substance under the Industrial Safety and Health Act. Thus, it can be said that the flame retardant of the present invention is excellent in handling properties not only from the perspective of environmental problems but also from the legal (regulatory) perspective.

Embodiments for Carrying Out the Invention

[0018] 1. Aqueous dispersion type flame retardant The aqueous dispersion type flame retardant (the flame retardant of the present invention) of the present invention is an aqueous dispersion type flame retardant in which a flame retardant component is dispersed in an aqueous solvent, (1) As the flame retardant component, it contains (1a) a metal salt of dialkylphosphinic acid and (1b) a bromine-based flame retardant component having a melting point of 150°C or lower (excluding the metal salt). (2) The ratio of the metal salt to the brominated flame retardant component is such that, with the total of both components being 100% by weight, the ratio of metal salt to brominated flame retardant component is 90% by weight:10% by weight to 40% by weight:60% by weight. It is characterized by the following:

[0019] The flame retardant of the present invention contains, as flame retardant components, at least a metal salt of dialkylphosphinic acid (hereinafter also referred to as the "first flame retardant component") and a brominated flame retardant component with a bromine content of 50-70% (hereinafter also referred to as the "second flame retardant component").

[0020] The first flame retardant component is a metal salt of dialkylphosphinic acid [HO-P(=O)R2] (where R represents an alkyl group). For example, a compound in which 2 to 4 dialkylphosphinic acid molecules are bonded to a metal can be used as the first flame retardant component. One or more of these can be used.

[0021] The alkyl group described above is not limited, but typically linear or branched alkyl groups having 1 to 6 carbon atoms can be preferably used. In particular, in this invention, R is preferably an ethyl group or a methyl group.

[0022] In this invention, examples of the central metal include aluminum, zinc, magnesium, and calcium. Among these, aluminum is preferred from the viewpoint of flame retardancy. Therefore, for example, aluminum diethylphosphinate (DEPAL) (tris(diethylphosphinate)aluminum), represented by the following formula (1), can be suitably used. In particular, since DEPAL does not have a clear melting point, it can effectively avoid the bleed-out problem that occurs when low-melting-point flame retardants are used.

[0023] [ka]

[0024] The solid content of the first flame retardant component in the flame retardant of the present invention can be appropriately set according to the desired flame retardancy, etc., but is usually sufficient to be around 20 to 60% by weight, and is particularly preferable to be 25 to 55% by weight.

[0025] As the second flame retardant component, a bromine-based flame retardant component with a melting point of 150°C or lower is used. In particular, by using a bromine-based flame retardant component with a melting point of 150°C or lower, excellent flame retardant performance can be achieved through a synergistic effect with the first flame retardant component.

[0026] The second flame retardant component preferably contains an alkyl group in which one or more hydrogen atoms are substituted with bromine atoms (bromine-substituted alkyl group). By using a second flame retardant component having such a bromine-substituted alkyl group, the drip properties during combustion are further improved, thereby achieving even higher flame retardancy. The reason for this is not entirely clear, but it is thought that (a) the bromine-based flame retardant that melts when heated exhibits a plasticizing effect on the fibers, and (b) aliphatic bromine compounds have a lower decomposition temperature than aromatic bromine compounds, and effectively exert flame retardant effects such as radical trapping from the initial stages of combustion of the resin or fibers.

[0027] The bromine-substituted alkyl group is not limited, but is preferably a linear alkyl group having 2 to 6 carbon atoms with one or more hydrogen atoms substituted, for example, a dibromopropyl group (particularly a 2,3-dibromopropyl group [-CH2CHBrCH2Br]). A second flame retardant component having one or more (preferably 2 to 4) such bromine-substituted alkyl groups can be suitably used. In the second flame retardant component, the bromine atom may be contained in the bromine-substituted alkyl group or bonded to other sites, as long as it does not hinder the effects of the present invention.

[0028] Furthermore, it is preferable to use a bromine-based flame retardant with a bromine content of 50-70% as the second flame retardant component. The bromine content is calculated as [(atomic weight of bromine atom (79.9) × total number of bromine atoms in the bromine-containing molecule) / molecular weight of the bromine-containing molecule] in the bromine-containing molecule that is the flame retardant component.

[0029] Such second flame retardant components are not particularly limited, and examples include at least one of tris(2,3-dibromopropyl) isocyanurate, bis[3,5-dibromo-4-(2,3-dibromopropoxy)phenyl]sulfone, and bis[3,5-dibromo-4-(2,3-dibromopropoxy)phenyl]propane. Among these, at least one of tris(2,3-dibromopropyl) isocyanurate (TBIC) and bis[3,5-dibromo-4-(2,3-dibromopropoxy)phenyl]sulfone (BDBPS) is preferred.

[0030] Tris(2,3-dibromopropyl)isocyanurate is a compound represented by the following formula (2).

[0031] [ka]

[0032] Bis[3,5-dibromo-4-(2,3-dibromopropoxy)phenyl]sulfone is a compound represented by the following formula (3).

[0033] [ka]

[0034] The solid content of the second flame retardant component in the flame retardant of the present invention can be appropriately set according to the desired flame retardancy, etc., but it is usually sufficient to set it to about 5 to 50% by weight, and it is particularly preferable to set it to 10 to 40% by weight.

[0035] Furthermore, in the present invention, the ratio of the first flame retardant component to the second flame retardant component is preferably such that, with the total of both components being 100% by weight, the ratio of the first flame retardant component to the second flame retardant component is 90% by weight:10% by weight to 40% by weight:60% by weight, and more preferably the ratio is 85% by weight:15% by weight to 50% by weight:50% by weight, and even more preferably the ratio is 85% by weight:15% by weight to 60% by weight:40% by weight. This makes it possible to obtain excellent flame retardancy and, in particular, to more effectively suppress the occurrence of whitening or chalk marks on the coated surface over time due to bleed-out (blooming) originating from the second flame retardant component.

[0036] In the flame retardant of the present invention, the above-mentioned components can be used as flame retardants, but other flame retardants other than the first and second flame retardants may be included as long as they do not hinder the effects of the present invention. For example, various flame retardants such as phosphorus-based flame retardants, nitrogen-based flame retardants, and sulfur-based flame retardants can be used in combination as needed.

[0037] However, as explained above, in the flame retardant of the present invention, it is desirable that the decabromodiphenylethane and antimony oxide be present in small amounts or none at all from the viewpoint of environmental issues. More specifically, it is more preferable that the total content of decabromodiphenylethane and antimony oxide be 0 to 1% by weight, and in particular, it is more preferable that the total amount be 0 to 0.1% by weight. Therefore, the total amount may be 0% by weight.

[0038] The flame retardant of the present invention takes the form of an aqueous dispersion. That is, the flame retardant components are dispersed in an aqueous solvent. As the aqueous solvent, (a) water, (b) a mixed solution of water and a water-soluble organic solvent, or (c) an aqueous solution obtained by dissolving a water-soluble solid substance in water can be used.

[0039] Examples of water-soluble organic solvents include monohydric alcohols such as ethanol, methanol, isopropyl alcohol, and butanol; polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, 1,8-propanediol, propylene glycol, 1,3-butylene glycol, 1,4-butanediol, 2,3-butylene glycol, neopentyl glycol, hexylene glycol, thiodiglycol, glycerin, trimethylolethane, trimethylolpropane, and diglycerin; and glycol ethers such as ethylene glycol monoethyl ether (ethyl cellosolve), ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether (ethyl carbitol), and diethylene glycol monobutyl ether. These can be used individually or in combination of two or more.

[0040] In the flame retardant of the present invention, it is preferable to use an aqueous solvent with a water content of 95 to 100% by weight, particularly from the viewpoint of reducing the burden on the environment. Therefore, an aqueous solvent with a water content of 100% by weight can also be suitably used.

[0041] The content of the aqueous solvent in the flame retardant of the present invention is not particularly limited as long as an aqueous dispersion can be prepared according to the desired solid content, but it is usually about 30 to 70% by weight, and particularly preferably 40 to 60% by weight.

[0042] Furthermore, the flame retardant of the present invention may contain other additives as long as they do not hinder the effects of the present invention. Examples include resin binders, surfactants, wetting agents, dispersants, thickeners, preservatives, UV absorbers, antioxidants, defoamers, pigments, dyes, deodorants, sewing improvers, finishing agents, softeners, water repellents, oil repellents, crosslinking agents, etc. The total amount of these additives (solid content ratio) (excluding the resin binder content) is usually 10% by weight or less, but is not limited to this.

[0043] In the flame retardant of the present invention, it is preferable to include at least one anionic surfactant and a nonionic surfactant. These surfactants function as dispersants, wetting agents, etc., for flame retardant components that are solid at room temperature, thereby enabling more reliable and uniform dispersion of these solid components in an aqueous dispersion.

[0044] Anionic surfactants are not particularly limited, but examples include alkylbenzene sulfonates, alkyl sulfonates (e.g., dialkyl sulfosuccinate ester salts), formalin condensates of naphthalene sulfonates, salts of sulfated EO adducts of cumylphenol (wherein "EO" means ethylene oxide; the same applies hereinafter), salts of sulfated EO adducts of distyrenated phenols, and salts of sulfated EO adducts of tristyrenated phenols. These anionic surfactants can be used individually or in combination of two or more. Commercially available products can also be used. Among these, in the present invention, dialkyl sulfosuccinate ester salts such as di-2-ethylhexyl sodium sulfosuccinate can be suitably used as wetting agents.

[0045] Nonionic surfactants are not particularly limited, but examples include EO adducts of phenol compounds such as cumylphenol EO adducts, distyrenated phenol EO adducts, and tristyrenated phenol EO adducts, as well as EO adducts of higher alcohols having 12 to 18 carbon atoms. These nonionic surfactants can be used individually or in combination of two or more. Commercially available products can also be used. Among these, EO adducts of phenol compounds can be used particularly suitably as dispersants.

[0046] The solid content of the surfactant in the flame retardant of the present invention is not particularly limited, but is usually about 1 to 5% by weight, and is particularly preferably 2 to 4% by weight. Note that the above solid content refers to the total amount when two or more surfactants are used.

[0047] Furthermore, it is preferable that the flame retardant of the present invention contains a resin binder. By including a resin binder in the flame retardant of the present invention, the adhesion of the flame retardant to fibers and the like can be improved.

[0048] The resin binder is not particularly limited, and at least one of the following can be suitably used: acrylic resin, polyurethane resin, polyester resin, SBR resin, etc. Acrylic resin is particularly preferred because it can more reliably impart a flexible texture to the processed fibers.

[0049] As for the type of acrylic resin, any resin used as a resin binder is acceptable, but acrylic resins with a low glass transition temperature (Tg) are more preferable from the viewpoint of more reliably imparting a flexible texture. In this case, the glass transition temperature is usually preferably below -10°C. As an acrylic resin with such a low glass transition temperature, for example, an acrylic resin having at least one of 2-ethylhexyl (meth)acrylate and n-butyl (meth)acrylate as monomer components is preferred. In particular, an acrylic resin that contains these two monomer components as main components and is composed of a copolymer with at least one other monomer such as acrylic monomers, styrene, vinyl chloride, vinylidene chloride, etc. Examples of the above acrylic monomers include at least one of (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, t-butyl (meth)acrylate, acrylonitrile, etc.

[0050] In this specification, unless otherwise specified, "(meth)acrylate" means acrylate or methacrylate, and "(meth)acrylic acid" means acrylic acid or methacrylic acid.

[0051] In the flame retardant of the present invention, it is preferable that the resin binder is composed of dispersed resin component particles. By adopting this form, the resin binder can be uniformly present together with the flame retardant components in the aqueous dispersion-type flame retardant of the present invention, thereby contributing to an effect of improving the adhesion of the flame retardant of the present invention to fibers and the like.

[0052] The solid content of the resin binder in the flame retardant of the present invention is not particularly limited, but is usually about 15 to 50% by weight, and is particularly preferably 20 to 40% by weight.

[0053] Furthermore, the solid content ratio of the flame retardant component to the resin binder, specifically the ratio of the flame retardant component (total amount A of the first and second flame retardant components) to the resin binder B, is preferably set to A:B = 60%:40% to 95%:5%, with a particular preference of 70%:30% to 90%:10%. By setting the ratio within this range, it is possible to enhance the adhesion of the flame retardant to fibers and the like, in addition to achieving excellent flame retardancy, thereby more effectively suppressing phenomena such as powder shedding.

[0054] In the flame retardant of the present invention, a thickening agent may be used to improve the stability of the product. In particular, since dialkylphosphinates dissociate with changes in pH, alkaline thickening agents are difficult to use. Therefore, it is preferable to use, for example, a polysaccharide-based thickening agent or an association-based thickening agent, and more preferably a polysaccharide-based thickening agent.

[0055] The flame retardant of the present invention has the form of an aqueous dispersion in which dispersed particles are dispersed in an aqueous solvent. However, the particle size of the dispersed particles is not limited, and for example, the average particle diameter can be about 0.1 to 10 μm, preferably 0.1 to 5 μm. This makes it possible to uniformly impart superior flame retardancy to fibers and the like. In the present invention, the average particle diameter of the dispersed particles is a value measured by laser diffraction and scattering.

[0056] The viscosity of the flame retardant of the present invention at room temperature (20°C) is not particularly limited, but from the viewpoint of dispersion stability, it is usually preferably 1,000 to 15,000 mPa·s, and more preferably 3,000 to 10,000 mPa·s.

[0057] The flame retardant of the present invention can be prepared, for example, by a method that includes the step of adding each of the above components to an aqueous solvent and mixing them. Therefore, the order in which each component is added is not particularly limited. Furthermore, the mixing can be carried out using known or commercially available equipment such as a mixer, kneader, or bead mill.

[0058] In this invention, it is preferable to mix each component in the form of an aqueous dispersion. This allows for the more reliable and easier preparation of an aqueous dispersion-type flame retardant by mixing them.

[0059] As the aqueous dispersion, an aqueous dispersion in which each component is dispersed in an aqueous solvent can be used. As the aqueous solvent, any of the above-mentioned aqueous solvents that can be used in the flame retardant of the present invention can be used, but water is particularly preferred.

[0060] Furthermore, the aqueous dispersion may contain other additives as needed. These additives can be any of the various additives used in the flame retardant of the present invention. Therefore, for example, an aqueous dispersion containing a) a flame retardant component (first flame retardant component or second flame retardant component), b) at least one of anionic surfactants and nonionic surfactants, c) an antifoaming agent, and d) water can be suitably used as a source for each component. In this case, it is preferable that the above aqueous dispersion (before mixing) does not contain a resin binder.

[0061] The method for preparing the aqueous dispersions of each component is not particularly limited, but if necessary, wet micronization can be performed to adjust the particle size of the dispersed particles. The wet micronization method is not particularly limited, and known micronization means or devices can be used, but a bead mill can be suitably used, for example.

[0062] In this case, the average particle size of the dispersed particles in the aqueous dispersion of each component is not limited, but is usually preferably 0.1 to 20 μm, more preferably 0.1 to 10 μm, and most preferably 0.1 to 5 μm.

[0063] Furthermore, when preparing the aqueous dispersion, which is the flame retardant of the present invention, the aqueous dispersion type flame retardant of the present invention can be obtained by a method that includes a step of mixing aqueous dispersions of each of these components with a raw material liquid containing a resin binder.

[0064] Thus, from the standpoint of ensuring the stability of the dispersion, it is preferable to incorporate the resin binder when mixing each aqueous dispersion. Furthermore, it is preferable to incorporate the resin binder in the form of an aqueous dispersion (water-based dispersion).

[0065] When mixing, there are no particular restrictions as long as the dispersed particles do not agglomerate (or re-agglomerate), and mixing can be carried out using general mixing or stirring equipment.

[0066] In the flame retardant of the present invention, the dispersed particles dispersed in the aqueous dispersion typically include resin particles of a resin binder, a first flame retardant component, and a second flame retardant component. As a result, the resin particles function as an adhesive that easily adheres to fibers and the like, enabling the first and second flame retardant components to be stably attached and fixed to fibers and the like.

[0067] 2. Flame-retardant fibers The present invention relates to a flame-retardant fiber comprising fibers and a flame-retardant component, (1) The flame retardant component includes a metal salt of dialkylphosphinic acid and a brominated flame retardant component (excluding the metal salt), (2) The ratio of the metal salt to the brominated flame retardant component is such that, with the total of both components being 100% by weight, the ratio of metal salt to brominated flame retardant component is 90% by weight:10% by weight to 40% by weight:60% by weight. This invention includes flame-retardant fibers (fibers of the present invention) characterized by the above.

[0068] The above-mentioned fibers may be natural fibers, semi-synthetic fibers, synthetic fibers, etc., but synthetic fibers are preferred, and among them, synthetic fibers made of thermoplastic resin are more preferred. The fiber form may also be either long fibers or short fibers. Furthermore, the fiber diameter may be, for example, about 5 to 50 μm, but is not limited to this.

[0069] The synthetic fiber is not particularly limited and may be any of the following: polyester fibers, polyamide fibers, polyolefin fibers, acrylic fibers, polyurethane fibers, etc. However, polyester fibers are preferred because they have little effect on the physical properties. The type of polyester resin that constitutes the polyester fiber is not limited and can be any of the following: a polyester resin containing at least one of the following: polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polytrimethylene terephthalate, copolymerized polyester resin, etc.

[0070] When polyester fibers are used as synthetic fibers, within the limits that do not impede the effects of the present invention, a) fibers such as mixed resins and polymer alloys of polyester resins with other synthetic resins, and b) fibers blended with polyester fibers and other synthetic or natural fibers (cotton, silk, linen, etc.) may also be treated with the flame retardant of the present invention. Furthermore, the fiber form may be either short fibers or long fibers. The fiber diameter is also not limited; for example, it may be about 5 to 50 μm, but is not limited thereto.

[0071] The fibers of the present invention may include not only the fibers (monofilaments) themselves, but also textile products made from the fibers, such as woven fabrics, nonwoven fabrics, and knitted fabrics. Furthermore, the textile products may contain one or more of the fibers of the present invention, and may also contain fibers other than those of the present invention. For example, the fibers of the present invention may include a polyester fiber alone and fibers other than those of the present invention (synthetic fibers or natural fibers). In these textile products, the basis weight may be, for example, 30 to 500 g / m². 2It can be set to a certain degree, but is not limited to that.

[0072] The fibers of the present invention can preferably be those in which the fibers have been made flame-retardant with the flame retardant of the present invention, and the flame retardant of the present invention is as described above.

[0073] The content of the flame retardant of the present invention in the fiber of the present invention can be appropriately set according to the intended use of the fiber, the desired flame retardancy, etc., but is usually about 5 to 40 parts by weight of the solid content of the first flame retardant and the second flame retardant per 100 parts by weight of fiber, and can be particularly 10 to 25 parts by weight, but is not limited to this.

[0074] The method for producing the fibers of the present invention is not particularly limited and can be carried out using known processing methods and processing equipment. For example, any of the following can be applied: padding, backing, dipping, dip-nip, exhaustion, spray, gravure, etc. Among these, dip-nip processing is particularly suitable for application in the present invention.

[0075] In particular, the present invention can suitably employ a method that includes (a) a step of applying the flame retardant of the present invention to fibers (flame retardant application step) and (b) a step of drying under heat (curing step).

[0076] In the flame retardancy imparting process, the flame retardant of the present invention is applied to the fibers. The method of applying the flame retardant is not particularly limited and can be carried out using known processing methods and processing equipment. For example, padding, backing, dipping, dip-nip, exhaustion, spray, gravure, etc., can all be applied. Among these, dip-nip processing is particularly suitable for application in the present invention.

[0077] This yields fibers containing the aqueous dispersion, which is the flame retardant of the present invention. Subsequently, it is preferable to remove the excess aqueous dispersion by squeezing. The squeezing ratio in this case is not limited, but can usually be appropriately set within a range of about 30 to 200%.

[0078] After being drawn out, flame-retardant fibers can be obtained by thoroughly drying them. While drying conditions are not limited, heat treatment can usually be performed in air at around 50-120°C, but is not limited to this. The heat treatment time can also be set within a range of, for example, 1 to 20 minutes, but other times are also possible.

[0079] Additionally, a curing process can be performed after drying, if necessary. This removes any remaining moisture, allowing the flame-retardant components to adhere more firmly to the fibers.

[0080] When performing the curing process, heat treatment can be carried out at, for example, 120-200°C in air, but is not limited to this. The heat treatment time can also be set within a range of, for example, 30 seconds to 10 minutes, but other times are also possible.

[0081] In this way, flame-retardant fibers containing the first and second flame-retardant components of the flame retardant of the present invention in predetermined proportions can be obtained. [Examples]

[0082] Examples and comparative examples are shown below to more specifically describe the features of the present invention. However, the scope of the present invention is not limited to these examples. In these examples, "%" means "weight percent" and "parts" means "parts by weight".

[0083] 1. About the raw materials used (1) Aqueous dispersion of aluminum diethylphosphinate (DEPAL) A solution was prepared by dispersing 2.0 parts of a nonionic surfactant (EO10 molar adduct of distyrenated phenol) as a nonionic dispersant, 2.0 parts of an anionic surfactant (sodium di-2-ethylhexyl sulfosuccinate) as an anionic wetting agent, and 0.1 part of a silicone-based defoamer in 45.9 parts of water. While vigorously stirring the solution, 50.0 parts of Clariant's DEPAL powder (product name: EXOLIT OP930, average particle size: approximately 3 μm) was slowly added. After adding the entire amount, stirring was continued for another 10 minutes to obtain a milky white aqueous dispersion of DEPAL (DEPAL concentration approximately 50%).

[0084] (2) TBIC water dispersion 2.5 parts of anionic surfactant (ammonium salt of a sulfated end of an EO13 molar adduct of distyrenated phenol) as an anionic dispersant, 2.5 parts of nonionic surfactant (EO10 molar adduct of cumylphenol) as a nonionic dispersant, 0.5 parts of anionic surfactant (sodium di-2-ethylhexyl sulfosuccinate) as an anionic wetting agent, and 0.1 parts of a silicone-based defoamer were dispersed in 44.4 parts of water. While vigorously stirring the solution, 50.0 parts of TBIC powder (product name: EB-70, melting point 117~121℃) manufactured by Manac Co., Ltd. were slowly added. The resulting crude dispersion was wet-milled using DynoMill (media: zirconia beads with particle size D50 = 0.5 mm) manufactured by Shinmaru Enterprises, Inc., to finely atomize the TBIC in the dispersion to an average particle size of approximately 1 μm, obtaining a milky white TBIC aqueous dispersion (TBIC concentration approximately 50%).

[0085] (3) BDBPS water dispersion A solution was prepared by dispersing 1.0 part of a nonionic surfactant (an EO10 molar adduct of cumylphenol) as a nonionic dispersant, 0.5 parts of an anionic polymer-type surfactant (a carboxyl group-containing polymer-modified product) as an anionic dispersant, and 0.1 parts of a silicone-based defoamer in 58.4 parts of water. While vigorously stirring the solution, 50.0 parts of crude powder of BDBPS (product name: Nonnen PR-2H, melting point 80-130°C) manufactured by Marubishi Yuka Kogyo Co., Ltd. was slowly added. The resulting crude dispersion was subjected to wet micronization in a ball mill for 10 hours to reduce the average particle size of the BDBPS in the dispersion to approximately 5 μm, obtaining a milky white aqueous dispersion of BDBPS (BDBPS concentration approximately 40%).

[0086] (4) Ethylene bistetrabromophthalimide (ETBPI) aqueous dispersion A solution was prepared by dispersing 2.5 parts of anionic surfactant (ammonium salt of a sulfated end of an EO13 molar adduct of distyrenated phenol) as an anionic dispersant, 2.5 parts of nonionic surfactant (EO10 molar adduct of cumylphenol) as a nonionic dispersant, 0.5 parts of anionic surfactant (sodium di-2-ethylhexyl sulfosuccinate) as an anionic wetting agent, and 0.1 parts of a silicone-based defoamer in 44.4 parts of water. While vigorously stirring the solution, 50.0 parts of Albemarle's ETBPI (trade name: Cytex BT-93, melting point approximately 456°C, bromine content approximately 67%) powder was slowly added. The obtained crude dispersion was subjected to wet atomization using a DynoMill manufactured by Shinmaru Enterprises (media: zirconia beads with a particle size D50 = 0.5 mm), resulting in micronization of the ETBPI in the dispersion to an average particle size of approximately 1 μm, and a milky white EBTBPI aqueous dispersion was obtained (ETBPI concentration approximately 50%).

[0087] (5) Decabromodiphenylethane (DBDPE) aqueous dispersion A solution was prepared by dispersing 2.0 parts of a nonionic surfactant (EO10 molar adduct of distyrenated phenol) as a nonionic dispersant, 2.0 parts of an anionic surfactant (sodium di-2-ethylhexyl sulfosuccinate) as an anionic wetting agent, and 0.1 part of a silicone-based defoamer in 25.9 parts of water. While vigorously stirring the solution, 70.0 parts of Albemarle's DBDPE powder (product name: Cytex 8010, average particle size: approximately 5 μm) was slowly added. After adding the entire amount, stirring was continued for another 10 minutes to obtain a milky white DBDPE aqueous dispersion (DBDPE concentration approximately 70%).

[0088] (6) Aqueous dispersion of decabromodiphenylethane (DBDPE) and antimony trioxide "Non-nen DE-13" manufactured by Marubishi Oil & Chemical Industries Co., Ltd.: A 70% aqueous dispersion of DBDPE and antimony trioxide mixed in a 3:1 (weight ratio).

[0089] (7) Water-based acrylic resin (7-1) "Polysol AP-4780N" manufactured by Resonaq Corporation (resin concentration approximately 50%) (7-2) MSV-210 manufactured by Aica Kogyo Co., Ltd. (resin concentration approximately 50%)

[0090] (8) Water-based urethane resin DIC Corporation's "Hydran HW-920" (resin concentration approximately 50%)

[0091] 2. Examples, etc. [Example 1] Each component described in item 1 above was prepared at room temperature in the proportions shown in Table 1. First, a predetermined amount of water was placed in a beaker, and while stirring with a powerful magnetic stirrer (stirring speed approximately 200 rpm), the first flame retardant component (DEPAL aqueous dispersion), the second flame retardant component (TBIC aqueous dispersion), and the resin binder (Polysol AP-4780N) were added to the water in that order. After that, the aqueous dispersion was prepared by uniformly stirring and mixing under the same conditions for approximately 5 minutes.

[0092] [Examples 2-7, Comparative Examples 1-8, and Reference Examples 1-2] Aqueous dispersions were prepared in the same manner as in Example 1, except that each of the components in item 1 above was mixed in the proportions shown in Tables 1 to 3.

[0093] [Table 1]

[0094] [Table 2]

[0095] [Table 3]

[0096] [Test Example 1] The flame retardancy of the aqueous dispersions obtained in each example, comparative example, and reference example was evaluated. The results are shown in Tables 1 to 3.

[0097] (1) Preparation of flame-retardant test cloth The aqueous dispersions prepared in each example and comparative example were used to perform flame retardant treatment on polyester fabric. More specifically, the weight is approximately 200g / m². 2 A polyester fabric was immersed in an aqueous dispersion to impregnate it (dip-nip method, squeezing rate: approximately 110%). The polyester fabric impregnated with the aqueous dispersion was removed and pre-dried at 80°C for 10 minutes, and then cured at 150°C for 1 minute to obtain a flame-retardant fabric as a test fabric.

[0098] (2) Evaluation of flame retardancy (45° microburner test (afterflame test)) For the above test cloth, the afterflame time (seconds) and burning area (cm²) were measured using the A-1 method (microburner method) described in the Japanese Industrial Standard "JIS L 1091 (1999)". 2 The flame retardancy was evaluated by measuring the flame retardancy. The evaluation criteria are as shown in Table 4, "Evaluation Criteria for Flame Retardant Performance of the 45° Microburner Method." (Indicators: Afterflame time (seconds), Carbonization area (cm²) 2In all cases, a smaller number indicates higher flame retardancy. This test evaluated the test cloth based on four points: flame ignition from the surface (vertical and horizontal directions) and flame ignition from the back (vertical and horizontal directions). A sample was judged as "passing" if it met the evaluation criteria in all four points. No residual dust was observed in any of the samples, and the afterflame time equaled the residual dust time.

[0099] [Table 4]

[0100] As is clear from the results in Tables 1-3, the flame retardant of the present invention can be considered a useful post-processing type flame retardant for polyester fibers. In particular, it can be seen that it exhibits flame retardancy equivalent to or better than conventional flame retardants using DBDPE and antimony trioxide in combination.

[0101] In particular, it was found that even with equivalent bromine content, agents using ETBPI as a brominated flame retardant exhibited lower flame retardancy, demonstrating a correlation between melting point and flame retardancy.

[0102] Thus, it can be seen that the present invention provides an excellent flame retardant that can serve as a substitute for antimony trioxide and DBDPE.

Claims

1. A water-based dispersion type flame retardant comprising a flame retardant component dispersed in an aqueous solvent, (1) The flame retardant component comprises (1a) a metal salt of dialkylphosphinic acid and (1b) a brominated flame retardant component having a melting point of 150°C or less (excluding the metal salt). (2) The ratio of the metal salt to the brominated flame retardant is such that, with the total of both being 100% by weight, the ratio of metal salt to brominated flame retardant is 90% by weight:10% by weight to 40% by weight:60% by weight. A water-based dispersion-type flame retardant characterized by the following features.

2. The aqueous dispersion type flame retardant according to claim 1, further comprising a resin binder.

3. The aqueous dispersion-type flame retardant according to claim 1, further comprising at least one anionic surfactant and a nonionic surfactant.

4. The aqueous dispersion type flame retardant according to claim 1, wherein the average particle size of the dispersed particles in the aqueous dispersion type flame retardant is 0.1 to 20 μm.

5. The aqueous dispersion-type flame retardant according to claim 1, wherein the total content of decabromodiphenylethane and antimony oxide is 0 to 1% by weight.

6. Flame-retardant fibers containing fibers and flame-retardant components, (1) The flame retardant component includes a metal salt of diethylphosphinic acid and a brominated flame retardant component (excluding the metal salt), (2) The ratio of the metal salt to the brominated flame retardant is such that, with the total of both being 100% by weight, the ratio of metal salt to brominated flame retardant is 90% by weight:10% by weight to 40% by weight:60% by weight. A flame-retardant fiber characterized by the following properties.

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