JP2024005643A - Flame-retardant coating agent, and method for manufacturing flame-retardant sheet material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-halogen flame-retardant coating agent which can impart sufficient flame retardancy even to an artificial leather subjected to perforation treatment, and a method for manufacturing a flame-retardant sheet material using the flame-retardant coating agent.

SOLUTION: A flame-retardant coating agent contains a flame-retardant component (A) containing phosphoramidate (a1) represented by the following formula (1), and an acrylic resin (B) including a structural unit derived from acrylonitriles (b1).

SELECTED DRAWING: None

COPYRIGHT: (C)2024,JPO&INPIT

Description

This application discloses flame retardant coatings and methods of making flame retardant sheet materials.

BACKGROUND ART Sheet materials, such as woven fabrics, knitted fabrics, and nonwoven fabrics impregnated with resin, are used in various fields such as clothing, furniture, and automobiles. In particular, artificial leather (for example, a non-woven fabric made from ultra-fine thermoplastic synthetic fibers impregnated with a polymeric elastic material such as polyurethane resin) and the raised surface of ultra-fine thermoplastic synthetic fibers are created by buffing the surface. The suede-like napped artificial leather formed on the surface has a soft touch, texture, and high-class appearance, so it is widely used as a material for high-end clothing. It is also being used for material purposes.

In the field of vehicle seat material applications, particularly excellent flame retardant performance is required, so it is known to back coat the seat material with a resin containing a flame retardant, that is, perform flame retardant backing processing. . Halogen-based flame retardants such as decabromodiphenyl ether have traditionally been used as such flame retardants, but in recent years, there has been a demand for the use of non-halogen-based flame retardants instead of halogen-based flame retardants from the perspective of environmental protection. It is being However, non-halogen flame retardants generally have inferior flame retardancy compared to halogen flame retardants, and it is often necessary to use a large amount of flame retardant in order to obtain flame retardancy. Use of excessive flame retardant may cause various problems and is not preferred.

On the other hand, in recent years, seat materials made of artificial leather have been made with tricot of a different color on the back side of the perforated artificial leather, in order to give the design a distinctive feature. Designs that create a sense of contrast by pasting materials together are often used. Although it is possible to impart flame retardant performance to a certain extent to plain sheet materials that have not been perforated using conventionally known flame retardant finishing agents, it is possible to impart flame retardant properties to a certain extent to sheet materials that have undergone perforation treatment. It is difficult to impart combustion performance.

For example, Patent Document 1 describes a flame retardant agent that includes at least a phosphoric acid compound A having a solubility in water of 1% or less, a vinyl group-containing resin C that forms a carbonized skeleton when burned, and a water-insoluble thickener D; describes a suede-like artificial leather in which the flame retardant is applied to one side of a thermoplastic synthetic fiber fabric. Further, Patent Document 2 describes a flame-retardant aqueous resin composition containing a flame retardant having a phosphoroamidate compound having a specific structure and an aqueous resin emulsion. Furthermore, Patent Document 3 describes a flame retardant processing agent in which a phosphoroamidate with a specific structure is dispersed in water using a copolymer surfactant having an organic carboxylic acid constituent unit and a specific hydrocarbon constituent unit. is listed. However, it is difficult for any of the flame retardant agents described in Patent Documents 1 to 3 to impart sufficient flame retardant performance to perforated sheet materials.

Note that, as in Patent Document 4, a technique is also known in which a flame retardant film is bonded to a surface layer made of perforated artificial leather to form a resin layer. However, when bonding flame-retardant films together, problems remain in terms of increased costs and increased time required due to additional processing steps.

Japanese Patent Application Publication No. 2007-016357 International Publication No. 2014/002958 JP 2018-145224 Publication Japanese Patent Application Publication No. 2016-193503

In view of the above background art, the present application provides a flame retardant coating agent that can impart sufficient flame retardancy not only to plain sheet materials but also to perforated sheet materials, and the related art. A method of manufacturing a flame retardant sheet material using a flame retardant coating agent is disclosed.

This application discloses the following multiple aspects as means for solving the above problems.

(Aspect 1)
A flame retardant component (A) containing a phosphoroamidate (a1) represented by the following formula (1),
an acrylic resin (B) containing a structural unit derived from acrylonitriles (b1);
flame-retardant coatings, including

(Aspect 2)
The acrylonitrile (b1) is contained in an amount of 5 to 30% by mass based on the total amount of monomers constituting the acrylic resin (B),
The mass ratio of the flame retardant component (A) and the acrylic resin (B) is (A):(B) = 99:1 to 50:50.
Flame retardant coating agent according to aspect 1.

(Aspect 3)
The flame retardant component (A) further contains a phosphorus compound (a2) other than the phosphoroamidate (a1),
The flame retardant coating agent according to aspect 1 or 2.

(Aspect 4)
further comprising a thickener (C);
The flame retardant coating agent according to any one of aspects 1 to 3.

(Aspect 5)
By treating one side of the sheet material with the flame retardant coating agent according to any one of aspects 1 to 4 and drying, the flame retardant coating agent is applied to one or both of the surface of the sheet material and the inside of the sheet material. forming a film containing a combustion component (A) and the acrylic resin (B);
A method for producing a flame retardant sheet material, comprising:

According to the flame retardant coating agent of the present disclosure, it is possible to impart sufficient flame retardancy to a sheet material. For example, it is possible to impart sufficient flame retardancy not only to plain sheet materials that have not been perforated, but also to sheet materials that have been perforated. Furthermore, according to the flame retardant coating agent of the present disclosure, the dye on the surface of the artificial leather or in the artificial leather may bleed (for example, the dye may bleed from the artificial leather part of the perforated sheet material to the tricot material part). color migration) is also easy to suppress.

1. Flame Retardant Coating Agent A flame retardant coating agent according to one embodiment will be described below. The flame retardant coating agent according to one embodiment includes a flame retardant component (A) containing a phosphoroamidate (a1) represented by the following formula (1), and an acrylic resin containing a structural unit derived from acrylonitriles (b1). Resin (B).

1.1 Flame retardant component (A)
The flame retardant component (A) contains phosphoroamidate (a1) represented by the above formula (1). Further, the flame retardant component (A) may contain other flame retardant components in addition to the phosphoroamidate (a1). For example, the flame retardant component (A) may include, in addition to the phosphoroamidate (a1), one of a phosphorus compound (a2) other than the phosphoroamidate (a1) and another flame retardant component (a3), or It may further include both.

1.1.1 Phosphoramidate (a1)
In the flame-retardant coating, the phosphoroamidate (a1) can for example be present as particles. The particles of phosphoroamidate (a1) may have an average particle diameter of, for example, 0.1 μm to 20 μm. The average particle diameter is preferably 0.3 μm or more and 10 μm or less, more preferably 0.5 μm or more and 5 μm or less. If the particle size of phosphoroamidate (a1) is too small, there will be no problem in terms of flame retardancy, but the time required for mechanical crushing to make the particles into fine particles will be longer, which will be disadvantageous in terms of manufacturing costs. There is. On the other hand, if the particle size of the phosphoroamidate (a1) is too large, separation of the flame-retardant coating agent tends to occur, and storage stability may decrease. Furthermore, if the particle size of the phosphoroamidate (a1) is too large, the flame retardance may deteriorate and the quality may deteriorate due to whitening of the surface coated with the flame retardant coating agent. The "average particle diameter" of phosphoroamidate (a1) contained in the flame-retardant coating agent is determined by measuring the cumulative volume particle size distribution using a laser diffraction/scattering particle size distribution measuring device, and the cumulative volume is 50. % particle diameter (median diameter, D50).

A commercially available product may be used as the phosphoroamidate (a1). Examples of commercially available phosphoroamidate (a1) include Daiguard 850 manufactured by Daihachi Kagaku Kogyo Co., Ltd.

1.1.2 Phosphorus compound (a2)
From the viewpoint of the balance between flame retardancy and physical properties other than flame retardancy, it is preferable that the flame retardant component (A) further contains a phosphorus compound (a2) other than the phosphoroamidate (a1). Examples of the phosphorus compound (a2) include ammonium polyphosphate, melamine polyphosphate, 9,10-dihydro-10-benzyl-9-oxa-10-phosphaphenanthrene-10-oxide (BCA), phosphoric acid amide, and phosphazene. The compound may be at least one selected from resorcinol bis-diphenyl phosphate (RDP), bisphenol A bis-diphenyl phosphate (BDP), and resorcinol bis-dixylenyl phosphate (RDX).

The phosphorus compound (a2) other than the phosphoroamidate (a1) preferably has a solubility in ion-exchanged water at 20°C of 1% by weight or less. In addition, the phosphorus compound (a2) is preferably ammonium polyphosphate from the viewpoint of flame retardant performance. More preferred is ammonium polyphosphate. Kiwatsuki is a phenomenon in which when water or steam adheres to a sheet material treated with a flame-retardant coating and dries, the areas to which the water or steam had adhered become spots or ring-like stains. This phenomenon occurs when components contained in the flame-retardant sheet material dissolve in the attached water or steam.

More preferably, the surface-coated ammonium polyphosphate is one or both of silane-coated ammonium polyphosphate and melamine-coated ammonium polyphosphate. From the viewpoint of not generating volatile organic compounds (VOC), silane-coated ammonium polyphosphate is more preferred.

Commercial products of silane-coated ammonium polyphosphate include FR CROS486 (manufactured by Budenheim), Exflam APP-204 (manufactured by Wellchem), APP-102, APP-105 (manufactured by JLS), and APP-5 (manufactured by Xi'an Kako). Commercial products of melamine-coated ammonium polyphosphate include Exolit AP462 (manufactured by Clariant), TERRAJU C-60 (manufactured by CBC), and Exflam APP202. (manufactured by Wellchem), etc.

In addition, when the flame retardant component (A) contains a phosphoric acid ester as the phosphorus compound (a2), in particular, one or both of resorcinol bis-diphenyl phosphate (RDP) and bisphenol A bis-diphenyl phosphate (BDP). , it is possible to obtain artificial leather with a relatively soft texture. Furthermore, when the flame retardant component (A) contains resorcinol bis-dixylenyl phosphate (RDX) as the phosphorus compound (a2), artificial leather with a relatively hard texture can be obtained.

1.1.3 Other flame retardant components The flame retardant component (A) may contain other flame retardant components (a3) other than the above-mentioned phosphoroamidate (a1) or phosphorus compound (a2). good. The other flame retardant component (a3) may be, for example, one or both of a brominated flame retardant and an inorganic flame retardant.

1.1.4 Ratio of each component contained in the flame retardant component (A) The amount of phosphoroamidate (a1) contained in the flame retardant component (A) is not particularly limited. For example, the flame retardant component (A) contains phosphoroamidate (a1) in more than 0% by mass and 100% by mass or less, preferably from 5 to 99% by mass, more preferably from 15 to 90% by mass, even more preferably from 20 to 90% by mass. It may also contain % by mass.

When the flame retardant component (A) contains phosphoroamidate (a1) and a phosphorus compound (a2) other than phosphoroamidate (a1), the mass ratio of (a1) and (a2) is particularly It is not limited. For example, it is preferable that (a1):(a2)=99:1 to 5:95, more preferably 90:10 to 15:85, even more preferably 90:10 to 20:80. . When the mass ratio of phosphoroamidate (a1) is high, the cost tends to increase. Furthermore, if the mass ratio of the phosphorus compound (a2) is large, there is a risk that flame retardancy may be insufficient, the fastness to friction may be reduced, color transfer may be worsened (color transfer becomes easier), and scratches may occur.

The flame retardant component (A) contains phosphoroamidate (a1) and one or both of a phosphorus compound (a2) other than the phosphoroamidate (a1) and other flame retardant components (a3). In this case, the mass ratio of (a1) to (a2) and (a3) is not particularly limited. For example, (a1):[(a2)+(a3)]=99:1 to 5:95 is preferable, more preferably 90:10 to 15:85, and 90:10 to 20:80. It is more preferable that When the mass ratio of phosphoroamidate (a1) is high, the cost tends to increase. In addition, if the mass ratio of phosphorus compounds (a2) other than phosphoroamidate (a1) and other flame retardant components (a3) is high, flame retardancy will be insufficient, the color fastness will decrease, and color transfer will worsen (color (the transition becomes easier), and there is a risk that there will be some stiffness.

1.2 Acrylic resin (B)
The acrylic resin (B) contains structural units derived from acrylonitriles (b1). In addition to the structural units derived from acrylonitriles (b1), the acrylic resin (B) may contain structural units derived from other monomers. For example, the acrylic resin (B) includes a structural unit derived from acrylonitriles (b1), a structural unit derived from a monomer (b2) represented by the following general formula (2), and a structural unit represented by the following general formula (3). and at least one kind of structural unit derived from the other monomer (b4).

1.2.1 Acrylonitrile (b1)
Specific examples of acrylonitriles (b1) include at least one selected from (meth)acrylonitrile, α-chloroacrylonitrile, and α-ethyl acrylonitrile. Here, (meth)acrylonitrile means either or both of acrylonitrile and methacrylonitrile.

1.2.2 Monomer (b2)
The acrylic resin (B) may contain a structural unit derived from a monomer (b2) represented by the following general formula (2).
CH ₂ =C(R ¹ )-C(O)-OR ² ...(2)
In formula (2), R ¹ is hydrogen or a methyl group, and R ² is an alkyl group having 1 to 12 carbon atoms or an alkenyl group having 2 to 12 carbon atoms.

In the above formula (2), R ² is preferably a linear alkyl group or alkenyl group, or a branched alkyl group or alkenyl group. Specific examples of the alkyl group having 1 to 12 carbon atoms constituting ^R2 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, pentyl group, hexyl group, and 2-ethylhexyl group. Examples include groups. From the viewpoint of preventing hand hardening, ^R2 is preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, and more preferably an alkyl group having 1 to 8 carbon atoms. It is even more preferable. Specific examples of monomer (a) include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, and sec-butyl (meth)acrylate. Acrylate, tert-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, 2-propenyl (meth)acrylate Examples include acrylate, and from the viewpoint of preventing hand hardening, methyl methacrylate, butyl (meth)acrylate, and 2-ethylhexyl acrylate are preferred. Monomer (b2) can be used alone or in combination of two or more.

1.2.3 Monomer (b3)
The acrylic resin (B) may contain a structural unit derived from a monomer (b3) represented by the following general formula (3).
_CH2 =C( ^R3 )-X- ^R4 -OH...(3)
In formula (3), R ³ is hydrogen or a methyl group, X is C(O)O or C(O)N(H), and R ⁴ is an alkylene group having 1 to 8 carbon atoms.

In the above formula (3), R ⁴ may be linear or branched. Specific examples of the alkylene group having 1 to 8 carbon atoms include methylene group, ethylene group, propylene group, and hexylene group. From the viewpoint of flame retardancy, ^R4 is preferably an alkylene group having 1 to 6 carbon atoms, more preferably an alkylene group having 1 to 5 carbon atoms, and preferably an alkylene group having 1 to 4 carbon atoms. is even more preferable. From the same viewpoint, R ³ is preferably a methyl group. Specific examples of monomer (b3) include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, N-(3-hydroxypropyl) (meth) Examples include acrylamide, and from the viewpoint of flame retardancy, 2-hydroxyethyl methacrylate is preferred. In the present disclosure, (meth)acrylic means either acrylic or methacrylic, and (meth)acrylate means either acrylate or methacrylate. Monomer (b3) can be used alone or in combination of two or more.

1.2.4 Other monomers (b4)
The acrylic resin (B) may contain a monomer (b4) other than the above monomers (b1) to (b3). Other monomers (b4) are not particularly limited as long as they are copolymerizable with monomers (b1) to (b3), but examples include acrylic acid, methacrylic acid, crotonic acid, and itaconic acid. , carboxyl group-containing unsaturated monomers (monomers with a carboxyl group in the molecule) such as maleic acid, fumaric acid, and maleic anhydride, aromatic unsaturated monomers such as styrene and α-methylstyrene, etc. can be mentioned. From the viewpoint of ease of polymerization with acrylonitriles (b1) and stability of the emulsified dispersion, the other monomer (b4) preferably contains a carboxyl group-containing unsaturated monomer, and acrylic acid and More preferably, it contains one or both of methacrylic acids. Moreover, from the viewpoint of flame retardancy, it is preferable that styrene is included. The other monomers (b4) can be used alone or in combination of two or more.

1.2.5 Ratio of each monomer in the acrylic resin (B) The ratio of the structural units derived from the above monomers in the acrylic resin (B) is not particularly limited. For example, the acrylonitrile (b1) is preferably contained in an amount of 5 to 30% by mass, more preferably 5 to 20% by mass, and 8 to 16% by mass, based on the total amount of monomers constituting the acrylic resin (B). It is even more preferable that the amount is contained in % by mass. That is, in the acrylic resin (B), [constituent units derived from acrylonitriles (b1)]: [constituent units derived from monomers other than acrylonitriles (b1)] = 5:95 to 30:70. The ratio is preferably 5:95 to 20:80, and even more preferably 8:92 to 16:84. If the amount of structural units derived from acrylonitriles (b1) is too small, the color fastness to rubbing and color transfer may deteriorate, and the storage stability of the processing agent may deteriorate. Furthermore, when the acrylonitrile (b1) is contained in an amount of 30% by mass or less based on the total amount of monomers constituting the acrylic resin (B), the appearance of flirting tends to be low. That is, by containing 5 to 30% by mass of acrylonitriles (b1) based on the total amount of monomers constituting the acrylic resin (B), it is possible to impart excellent flame retardancy to the sheet material, as well as excellent friction properties. Fastness is ensured, color migration is suppressed, storage stability is improved, and staining is less likely to occur.

Acrylic resin (B) contains at least one of a structural unit derived from a monomer (b2), a structural unit derived from a monomer (b3), and a structural unit derived from another monomer (b4). When seeds are included, the ratio of these monomers (b2) to (b4) is not particularly limited. For example, the mass ratio of monomer (b2) to monomer (b3) is preferably (b2):(b3)=100:0 to 90:10, and (b2):(b3)= More preferably, the ratio is 100:0 to 95:5. Further, for example, the mass ratio of monomer (b2) to other monomer (b4) is preferably (b2):(b4)=99.5:0.5 to 70:30, More preferably, the ratio is 99.5:0.5 to 80:20.

1.2.6 Glass transition temperature of acrylic resin (B) Acrylic resin (B) preferably has a glass transition temperature (Tg) of -50°C to 5°C, and a Tg of -40°C to -10°C. It is more preferable to have a Tg of -40°C to -20°C even more preferably. When Tg is less than -50°C, the surface of the flame-retardant sheet material becomes tacky, and the resulting sheet material may be difficult to handle. Since the higher the Tg, the harder the texture tends to be, the Tg is preferably 5°C or lower, more preferably 0°C or lower, and even more preferably -5°C or lower. The glass transition temperature (Tg) of the acrylic resin (B) can be calculated from the glass transition temperature and composition ratio of each monomer.

1.2.7 Commercially available acrylic resin (B) Acrylic resin B may be a commercially available product. Commercially available products include the Boncourt series, the Watersol series (manufactured by DIC Corporation) that contain structural units derived from acrylonitriles, and the Nikazol series (manufactured by Nippon Carbide Industries Co., Ltd.). Examples include those containing structural units derived from acrylonitriles, and those containing structural units derived from acrylonitriles in the Cybinol series (for example, Cybinol EC-072, manufactured by Saiden Chemical Co., Ltd.).

1.2.8 Synthesis method of acrylic resin (B) Acrylic resin (B) can be synthesized, for example, by the following method. Although not particularly limited, for example, in the presence of water, a surfactant, an emulsifying dispersant, 0.01 to 5 parts by mass of a chain transfer agent (per 100 parts by mass of monomers in total), a polymerization initiator, etc. as necessary. Then, by emulsifying and dispersing monomer (b1) and monomers (b2) to (b4) in the above-mentioned mass ratio, an emulsified dispersion of acrylic resin (B) can be obtained. In this disclosure, emulsification and dispersion are collectively expressed as emulsification and dispersion.

In addition to water, an organic solvent can be used as a solvent in the emulsion dispersion polymerization depending on the case. Examples of such organic solvents include glycols such as ethylene glycol, diethylene glycol, butyl glycol, and butyl diglycol, and alcohols such as methanol, ethanol, and isopropanol.

In the above emulsion dispersion polymerization, commonly used known non-reactive surfactants such as nonionic, anionic, cationic, or amphoteric surfactants, and reactive surfactants having polymerizable groups such as vinyl groups or allyl groups. can be used. One type of surfactant or a combination of two or more types can be used.

The content of the surfactant is preferably in the range of 0.1 to 10 parts by mass per 100 parts by mass of the total monomers, and the total concentration of the monomers in the emulsion when producing the acrylic resin (B) is 30 parts by mass. ~73% by mass is preferred.

Nonionic surfactants include, for example, alkylene oxide adducts of linear or branched C8-C24 alcohols or alkenols, alkylene oxide adducts of monocyclic or polycyclic phenols, and linear or branched alkylene oxide adducts. Alkylene oxide adducts of aliphatic amines with a chain of 8 to 44 carbon atoms, alkylene oxide adducts of linear or branched chain fatty acid amides with 8 to 44 carbon atoms, linear or branched chain fatty acids with 8 to 24 carbon atoms Examples include alkylene oxide adducts of polyhydric alcohols, linear or branched fatty acids having 8 to 24 carbon atoms, and alkylene oxides, and alkylene oxide adducts of oils and fats.

Examples of anionic surfactants include sulfuric acid ester salts, phosphoric acid ester salts, carboxylic acid salts, and sulfosuccinic acid type anionic surfactants of the nonionic surfactants, sulfuric acid ester salts and phosphoric acid ester salts of higher alcohols, oils and fats. Examples include sulfonated products of the same class, alkylbenzene sulfonates, alkylnaphthalene sulfonates, and formalin condensates of naphthalene sulfonates.

Examples of cationic surfactants include aliphatic amine salts, their quaternary ammonium salts, and aromatic quaternary ammonium salts; examples of amphoteric surfactants include carboxybetaine, sulfobetaine, aminocarboxylate, and imidazoline. Examples include derivatives.

Among these, from the viewpoint of emulsification dispersibility and stability, alkylene oxide adducts of linear or branched alcohols having 8 to 24 carbon atoms, alkylene oxide adducts of monocyclic or polycyclic phenols, and their anions At least one selected from the group consisting of compounds is preferred.

Examples of monocyclic or polycyclic phenols include (3 to 8 mol) styrene adducts, (3 to 8 mol) α-methylstyrene adducts of phenol, 4-cumylphenol, 4-phenylphenol, or 2-naphthol. or (3 to 8 moles) benzyl chloride reactants are preferred.

The chain transfer agent is not particularly limited, but for example, mercaptan compounds, alcohols, and the like can be used. Examples of the mercaptan compounds include n-hexyl mercaptan, n-octyl mercaptan, t-octyl mercaptan, n-decyl mercaptan, n-dodecyl mercaptan, and t-dodecyl mercaptan. Also included are mercapto group-containing alcohols such as mercaptoethanol and mercaptopropanol. Examples of the alcohol include C1 to C6 aliphatic alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, and n-butyl alcohol, and C7 to C13 aromatic alcohols such as benzyl alcohol. Can be mentioned. Chain transfer agents other than these include α-methylstyrene dimer. One type of chain transfer agent or a combination of two or more types can be used. Preferred is a chain transfer agent having a mercapto group.

The polymerization initiator is not particularly limited, but known initiators commonly used in emulsion dispersion polymerization of acrylic resins can be used. For example, as a water-soluble polymerization initiator, persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate, hydrogen peroxide, and the like can be used alone or in combination. As an oil-soluble polymerization initiator, one or more types of peroxides such as benzoyl peroxide and lauroyl peroxide, azobis compounds such as azobisisobutyronitrile and azobisvaleronitrile, and polymer azo polymerization initiators are used. can be used in combination. A water-soluble polymerization initiator and an oil-soluble polymerization initiator can also be used in combination. Further, a redox initiator consisting of a combination of the above peroxide and a reducing agent such as sodium bisulfite, sodium thiosulfate, Rongalit, ascorbic acid, etc. can also be used.

The emulsion dispersion polymerization can be carried out by heating the monomer mixture in an aqueous liquid with stirring in the presence of a chain transfer agent, a polymerization initiator, an emulsification dispersant, etc. as necessary. The reaction temperature is, for example, about 30 to 100°C, and the reaction time is, for example, about 1 to 10 hours. The reaction temperature can be adjusted by adding the monomer mixture or the monomer emulsion dispersion all at once or dropwise for a while into a reaction vessel containing water and a polymerization initiator.

Emulsion dispersion polymerization can be carried out using any of the following methods: the usual one-stage continuous monomer uniform dropping method, the multi-stage monomer feed core-shell polymerization method, and the power-feed polymerization method that continuously changes the monomer composition fed during polymerization. A polymerization method can also be used.

From the viewpoint of maintaining a more stable emulsion of the acrylic resin (B), the content of the acrylic resin (B) in the emulsified dispersion is set to 40 to 60% by mass, and the pH of the emulsified dispersion is set to 6.0 to 9. It is preferable to adjust it to .0. The pH may be adjusted before, during, or after the polymerization reaction.

1.3 Thickener (C)
The flame retardant coating agent may contain a thickener (C). The thickener (C) adjusts the viscosity and viscosity of the flame-retardant coating agent, and adjusts the applicability to the sheet material. Thickeners (C) include natural organic polymers such as gum arabic, gum tragacanth, guar gum, locust bean gum, sodium alginate, carrageenan, xanthan gum, pullulan; methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose, etc. Semi-synthetic organic polymers such as polyvinyl alcohol, polyurethane resins, alkali-thickened acrylic resins, ethylene oxide higher fatty acid esters, polyethylene oxide, and other synthetic organic polymers can be used. One kind or two or more kinds of thickeners (C) can be used.

The thickener (C) is preferably water-insoluble from the viewpoint of suppressing stiffness. "Water-insoluble" means that if the thickener (C) is solid, it is powdered, then 10g of the thickener (C) is placed in 100g of ion-exchanged water at 20℃, This refers to the degree of dissolution (g) of thickener (C) in 100 g of ion-exchanged water of 1.0 g or less when vigorously shaken for 1 minute at ℃. "Dissolve" means to give a clear solution or to mix in a clear manner in any proportion. Examples of the water-insoluble thickener (C) include alkali thickening acrylic resins, ethylene oxide higher fatty acid esters, and combinations thereof.

As the alkali-thickening acrylic resin, one type of conventionally known alkali-thickening acrylic resin can be used alone or in combination of two or more types. The alkali thickening acrylic resin is preferably a polymer of a monomer composition containing at least one monomer selected from the group consisting of carboxyl group-containing monomers and (meth)acrylic acid ester monomers. In addition, when the said polymer corresponds to both an acrylic resin (B) and an alkali thickening type acrylic resin, it is considered that it is an acrylic resin (B).

Among such alkali-thickened acrylic resins, a monomer composition containing at least one monomer selected from the group consisting of carboxyl group-containing monomers and (meth)acrylic acid ester monomers is combined with a polymerization initiator, a surfactant, and Preferably, it is obtained by emulsion polymerization in the presence of a chain transfer agent, a crosslinking agent, etc., if necessary. The polymerization temperature is 5 to 100°C, preferably 50 to 80°C, and other conditions and methods may be carried out according to general polymerization conditions and methods, such as adding monomers etc. to the polymerization system. Examples of the addition method include a batch addition method, a continuous addition method, and a divided addition method, which may be employed.

Examples of carboxyl group-containing monomers that are constituents of alkali-thickened acrylic resins include monocarboxylic acid monomers such as (meth)acrylic acid, crotonic acid, cinnamic acid, and atropaic acid; itaconic acid, maleic acid, and fumaric acid. Examples include acid, dicarboxylic acid monomers such as citraconic acid and mesaconic acid, and their acid anhydrides; furthermore, dicarboxylic acid monoalkyl ester monomers and the like. Among these, acrylic acid and methacrylic acid are preferred, and methacrylic acid is particularly preferred.

Examples of (meth)acrylic acid ester monomers include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, ( sec-butyl meth)acrylate, tert-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, decyl (meth)acrylate, ( Dodecyl (meth)acrylate, Tetradecyl (meth)acrylate, Hexadecyl (meth)acrylate, Octadecyl (meth)acrylate, Icosyl (meth)acrylate, Henicosyl (meth)acrylate, Docosyl (meth)acrylate, (Meth) ) octadecenyl acrylate, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, etc., preferably ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, Butyl methacrylate is particularly preferred, and ethyl acrylate is particularly preferred.

In addition to at least one monomer selected from the group consisting of carboxyl group-containing monomers and (meth)acrylic acid ester monomers, monomers copolymerizable with these monomers are used as constituent components of the alkali-thickened acrylic resin. be able to. Examples of such copolymerizable monomers include vinyl carboxylate monomers, styrene monomers, hydroxyl group-containing monomers, amide group-containing monomers, and cyano group-containing monomers.

Vinyl carboxylate monomers include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl valerate, vinyl papyrate, vinyl caproate, vinyl octoate, vinyl nonanoate, vinyl decanoate, vinyl undecanoate, vinyl laurate, Examples include vinyl tridecanoate, vinyl myristate, vinyl palmitate, vinyl stearate, vinyl monochloroacetate, vinyl benzoate, and vinyl acetate and vinyl propionate are preferred. Styrenic monomers include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, o-isopropylstyrene, m- Examples include isopropylstyrene, p-isopropylstyrene, o-tert-butylstyrene, m-tert-butylstyrene, and p-tert-butylstyrene, with styrene being preferred. Hydroxyl group-containing monomers include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, polyoxyethylene mono(meth)acrylate, polyoxypropylene mono(meth)acrylate, polyoxybutylene mono (meth)acrylate, polyoxydecylene mono(meth)acrylate, polyoxydodecylene mono(meth)acrylate, polyoxytetradecylene mono(meth)acrylate, polyoxyhexadecylene mono(meth)acrylate, polyoxyocta Decylene mono(meth)acrylate, polyoxyicosylene mono(meth)acrylate, polyoxytriacontylene mono(meth)acrylate, polyoxyethylene polyoxypropylene mono(meth)acrylate, glycerin mono(meth)acrylate, pentaerythritol mono Examples include (meth)acrylate, (meth)allyl alcohol, and glycerin mono(meth)allyl ether. Examples of amide group-containing monomers include (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, N-butyl(meth)acrylamide, and N-methylol(meth)acrylamide. Acrylamide, N-ethylol (meth)acrylamide, N-hydroxypropyl (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, N-propoxymethyl (meth)acrylamide, N-butoxymethyl Examples include (meth)acrylamide, diacetone (meth)acrylamide, maleic acid amide, maleic acid imide, and the like. Examples of the cyano group-containing monomer include (meth)acrylonitrile, α-chloroacrylonitrile, α-ethyl acrylonitrile, and the like. In the above, (meth)acrylic means either acrylic or methacryl, (meth)acrylonitrile means either acrylonitrile or methacrylonitrile, and (meth)allyl means methallyl or allyl. means any of the following.

Polymerization initiators that can be used in the production of alkali-thickened acrylic resins include hydrogen peroxide, ammonium persulfate, potassium persulfate, redox initiators (hydrogen peroxide - ferrous chloride, ammonium persulfate - acidic sodium sulfite, Ascorbic acid (salt), Rongalit, etc.), 1,1-di-t-butylperoxy-2-methylcyclohexane, 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane, water-soluble Examples include radical donors such as azo initiators. Further, radicals may be generated by photopolymerization using ultraviolet rays, electron beams, radiation, etc. In this case, a photosensitizer or the like may be used.

Surfactants that can be used in the production of alkali-thickened acrylic resin include nonionic surfactants and anionic surfactants that can be used in emulsion dispersion polymerization of the hydroxyl group-containing acrylic resin B mentioned above. things can be used. In addition to these surfactants, compounds that have both a polymerizable group such as a vinyl group or an allyl group and a hydrophilic group such as a sulfonic acid group or a polyoxyethylene group, called reactive surfactants, can also be used effectively. can do. These surfactants can be used alone or in combination of two or more. The amount of surfactant added is preferably 0.1 to 10% by mass based on the total amount of monomers. If the amount added is less than 0.1% by mass, the polymerization reaction tends to be poor and the desired alkali-thickened acrylic resin cannot be obtained. When it exceeds 10% by mass, the effect of further improving the polymerization reaction is small, and the flame retardance and stiffness of the flame-retardant sheet material tend to decrease.

Chain transfer agents that can be used in the production of alkali-thickened acrylic resins include mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, and n-stearyl mercaptan, and pentaphenyl. Ethane, terpinolene, α-methylstyrene dimer, and other materials that can be used in ordinary emulsion polymerization can be used alone or in combination of two or more. Furthermore, the method of use may be one-time addition, divided addition, or continuous addition. The amount of the chain transfer agent used is preferably 2% by mass or less, more preferably 0.5% by mass or less based on the total amount of monomers. If the amount added exceeds 2% by mass, the alkali thickened acrylic resin tends to have a low molecular weight, making it difficult to obtain sufficient viscosity and viscosity.

The crosslinking agent that can be used in the production of alkali-thickened acrylic resin is not particularly limited as long as it is a compound having two or more radically polymerizable double bonds, but ethylene glycol di(meth) is an example. ) acrylate, propylene glycol di(meth)acrylate, glycerin di(meth)acrylate, glycerin tri(meth)acrylate, diethylene glycol di(meth)acrylate, diallyl phthalate, diallyl maleate, diallyl fumarate, allyl(meth)acrylate, N , N'-methylenebis(meth)acrylamide, divinylbenzene, etc., and can be used as necessary.

In addition, pH buffering agents, chelating agents, etc. may be used during polymerization. Examples of pH buffering agents include sodium bicarbonate, sodium carbonate, sodium dihydrogen phosphate, sodium phosphate, sodium acetate, potassium acetate, etc., and examples of chelating agents include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, etc. .

Such alkali-thickened acrylic resins are usually obtained as emulsified dispersions of resins and distributed on the market. It is preferable to use the alkali thickened acrylic resin in such an emulsified and dispersed state. As the alkali thickening acrylic resin (C), commercially available products can be used, such as Nikazol VT-253A (manufactured by Nippon Carbide Industries Co., Ltd.), Aron A-20P, Aron A-7150, Aron A- 7070, Aron B-300, Aron B-300K, Aron B-500 (manufactured by Toagosei Co., Ltd.), Julimar AC-10LHP, Julimar AC-10SHP, Rheosic 250H, Rheosic 835H, Junron PW-110, Junron PW- 150 (manufactured by Nippon Junyaku Co., Ltd.), Primal ASE-60, Primal TT-615, Primal RM-5 (manufactured by Rohm and Haas Japan Co., Ltd.), SN Thickener A-818, SN Thickener A -850 (manufactured by Sannopco Co., Ltd.), Paragum 500 (manufactured by Parachem Southern Co., Ltd.), Rheolate 430 (manufactured by Elementis Japan Co., Ltd.), Neosticker V-500 (manufactured by Nicca Chemical Co., Ltd.) (manufactured by).

Further, in order to adjust the applicability of the flame retardant coating agent, a polyurethane resin may be used in combination with the alkali thickening acrylic resin. Such polyurethane resins can be used in amounts of 0.3 to 1% by weight, based on the flame-retardant coating.

Examples of polyurethane resins that can be used in combination with alkali-thickened acrylic resins include nonionic polyether polyol-based urethane polymers.
Commercial products can be used as such polyether polyol-based urethane polymers, such as ADEKA NOL UH-420, ADEKA NOL UH-450, ADEKA NOL UH-540, ADEKA NOL UH-752 (manufactured by Asahi Denka Kogyo Co., Ltd.). , SN Thickener 601, SN Thickener 612, SN Thickener 621N, SN Thickener 623N (manufactured by San Nopco Co., Ltd.), Rheolate 244, Rheolate 278, Rheolate 300 (manufactured by Elementis Japan Co., Ltd.), DK Thickener SCT-275 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

Examples of the ethylene oxide higher fatty acid ester include polyethylene glycol monohigher fatty acid ester, polyethylene glycol dihigher fatty acid ester, polyethylene glycol castor oil ester, and polyethylene glycol hydrogenated castor oil ester. The degree of polymerization of polyethylene glycol is preferably 4 to 100. The higher fatty acid preferably has an alkyl group or an alkenyl group having 10 to 24 carbon atoms.

Commercially available ethylene oxide higher fatty acid esters include Ionet DO-4000, Ionet DO-800, Ionet DO-1000, Emulmin 862 (manufactured by Sanyo Chemical Co., Ltd.), Emanon 1112, Emanon 3199VB, Emanon 3299VB, Emanon 4110 ( (manufactured by Kao Corporation).

1.4 Ratio of flame retardant component (A), acrylic resin (B) and thickener (C) The ratio is not particularly limited. For example, the mass ratio of the flame retardant component (A) and the acrylic resin (B) in the flame retardant coating agent is preferably (A):(B) = 99:1 to 50:50, and 95:5. More preferably, the ratio is between 65:35, 95:5 and 75:25, or between 95:5 and 80:20. When the mass ratio of (A) and (B) is within this range, even more excellent flame retardance can be imparted to perforated sheet materials. The blending amount of the thickener (C) in the flame-retardant coating agent may be appropriately set according to the processing suitability of the coating machine.

1.5 Other matters 1.5.1 Other components The flame-retardant coating agent may contain components other than the above-mentioned flame-retardant component (A), acrylic resin (B), and thickener (C) (for example, other components). (resin). Further, when foam coating is performed, a foaming agent such as N,N-dimethyldodecylamine oxide or sodium dodecyl diphenyl ether disulfonate may be included. Furthermore, it may contain a dispersion medium, a surfactant, etc. for emulsification.

1.5.2 Viscosity and viscosity (PVI value)
The flame retardant coating agent can be used by adjusting the viscosity to suit the processing equipment used. Although the viscosity is not particularly limited, it is preferably 1,000 to 50,000 mPa·s, more preferably 3,000 to 30,000 mPa·s, and 6,000 to 12,000 mPa·s. It is even more preferable that it is s. If the viscosity is less than 1,000 mPa·s, strike-through may occur, and if the viscosity exceeds 50,000 mPa·s, blur may occur.

When foam-coating a flame-retardant coating agent onto a sheet material, the viscosity of the flame-retardant coating agent is preferably 500 to 15,000 mPa·s, more preferably 6,000 to 12,000 mPa·s. preferable. If it is less than 500 mPa·s, the product stability of the flame retardant coating agent tends to be poor, and if it exceeds 15,000 mPa·s, foaming may be poor.

The viscosity (unit: mPa・s) of the flame-retardant coating agent is determined by placing 200 ml of the flame-retardant coating agent in a glass bottle with an inner diameter of 50 mm, and using a B-type viscometer (Tokimec Co., Ltd., BM-type viscometer, No. 4 rotor). , 12 rpm, measurement temperature 20° C.).

From the viewpoint of obtaining good applicability of the flame retardant coating agent to the sheet material, it is preferable to adjust the viscosity within a specific range. Viscosity can be evaluated by PVI value. The PVI value is a printing viscosity index, and in the present disclosure, the viscosity of the flame retardant coating agent is measured under the above viscosity measurement conditions at a rotation speed of 60 rpm and 6 rpm, and is a value calculated by the following formula. .
PVI value = Measured value at a rotation speed of 60 rpm ÷ Measured value at a rotation speed of 6 rpm

The PVI value of the flame retardant coating agent is preferably 0.15 to 0.60, more preferably 0.19 to 0.40, even more preferably 0.19 to 0.25, Most preferably it is 0.19 to 0.21. When the PVI value is 0.15 or more, a sufficient amount of coating can be applied without causing blurring during coating, indicating processability. Furthermore, if the PVI value is greater than 0.60, there is a risk that the amount of coating may be excessive or that the texture may be hardened.

The viscosity and viscosity of the flame-retardant coating agent may be adjusted by changing the type and amount of the thickener (C).

1.5.3 Manufacturing conditions for flame retardant coating agent The method for obtaining the flame retardant coating agent is not particularly limited, and the flame retardant component (A), acrylic resin (B), and thickener (C) For example, the viscosity, pH, solid content, etc. may be adjusted by mixing and stirring arbitrary components such as the following. The order and method of blending each component can be changed as appropriate.

As a method for stirring and mixing, a conventionally known stirring device or emulsification dispersion device can be used. Conventionally known stirring devices and emulsifying and dispersing devices are not particularly limited, and include stirring devices such as propellers, colloid mills, bead mills, milders, homogenizers, ultrasonic homogenizers, homomixers, homodispers, nanomizers, ultimizers, starbursts, etc. Examples include emulsifying and dispersing machines.

From the viewpoint of preventing spot-like stains from occurring on the treated surface treated with the flame-retardant coating agent, it is desirable to use the flame-retardant component (A) after pulverizing it into fine particles in advance.

1.5.4 Emulsified dispersion As a flame retardant coating agent, a pre-emulsified dispersion of the flame retardant component (A), acrylic resin (B), and thickener (C) may be used (emulsified dispersion). can. When emulsifying the flame retardant component (A), acrylic resin (B), and thickener (C), a conventionally known stirring device or emulsification dispersion device similar to the above can be used.

A surfactant can be used when emulsifying and dispersing the flame retardant component (A), acrylic resin (B), and thickener (C). By using a surfactant, stable emulsification and dispersion can be achieved, the miscibility of each component is improved, and it becomes easier to produce a flame-retardant coating agent.

Such a surfactant is not particularly limited, and at least one kind selected from the same known nonionic, anionic, cationic, and amphoteric surfactants as mentioned above can be used.

Among these, from the viewpoint of emulsification dispersibility and stability, alkylene oxide adducts of linear or branched alcohols having 8 to 24 carbon atoms, alkylene oxide adducts of monocyclic or polycyclic phenols, and their anions Preferably, it is at least one selected from the group consisting of compounds.

Examples of monocyclic or polycyclic phenols include (3 to 8 mol) styrene adducts, (3 to 8 mol) α-methylstyrene adducts of phenol, 4-cumylphenol, 4-phenylphenol, or 2-naphthol. or (3 to 8 moles) benzyl chloride reactants are preferred.

The amount of surfactant contained in the flame-retardant coating agent is preferably 0.1 to 3 parts by weight based on 100 parts by weight of the total active ingredients. If it is less than 0.1 part by mass, the product stability of the flame-retardant coating agent may be reduced, and if it exceeds 3 parts by mass, the stiffness, fastness, and flame retardance of the flame-retardant sheet material may be reduced. There is a possibility.

1.5.5 Amount of Active Ingredients In the flame retardant coating agent, the total amount of active ingredients is preferably 20 to 60% by mass. If the total amount is less than 20% by mass, the amount of these components applied to the sheet material may be insufficient, resulting in a decrease in flame retardancy. If it exceeds 60%, the coating amount will be excessive, and in addition to reducing further improvement in flame retardancy, various fastnesses may deteriorate.

1.5.6 Average particle size The flame retardant coating agent preferably has an average particle size D50 of 0.5 to 30 μm, a maximum particle size Dmax of 200 μm or less, and an average particle size D50 of 0.5 to 30 μm. It is more preferable that the maximum particle diameter Dmax is 100 μm or less. If the average particle diameter D50 or maximum particle diameter Dmax is too large, the product stability of the flame-retardant coating agent may decrease, the flame retardance of the flame-retardant sheet material may decrease, or the surface of the flame-retardant sheet material may deteriorate. Powder may appear. If the average particle diameter D50 is too small, a large amount of time and cost will be required to reduce the particle diameter, which may be industrially unfavorable. The method for measuring the average particle diameter is as described above. In other words, the cumulative volume particle size distribution is measured using a laser diffraction/scattering particle size distribution analyzer, and the particle diameter (median diameter) at which the cumulative volume is 50% is defined as the average particle diameter D50, and the particles whose cumulative volume is 100% are defined as the average particle diameter D50. It can be determined by setting the diameter (maximum particle diameter) to the maximum particle diameter Dmax.

1.5.7 pH
The pH of the flame retardant coating agent is preferably 6.0 to 10.0, more preferably 7.0 to 9.0. When the pH is less than 6.0, the viscosity of the flame-retardant coating agent decreases, resulting in decreased product stability, difficulty in controlling the amount applied to the sheet material, and strike-through. If it exceeds 10.0, there may be a decrease in flame retardancy or deterioration of the fabric. In addition, pH is a value measured based on JIS Z 8802:2011.

1.6 Applications of Flame Retardant Coating Agent The flame retardant coating agent of the present disclosure can provide excellent flame retardance to various sheet materials. For example, the flame retardant coating agent according to one embodiment may be used to impart flame retardancy to a plain sheet material, or may be used to impart flame retardance to a perforated sheet material. It may also be used for According to the flame retardant coating agent of the present disclosure, it is possible to impart excellent flame retardancy not only to plain sheet materials but also to perforated sheet materials. Hereinafter, a method for manufacturing a flame-retardant sheet material using a flame-retardant coating agent will be described.

2. Method for manufacturing flame-retardant sheet material The technology of the present disclosure has an aspect as a method for manufacturing a flame-retardant sheet material in addition to the aspect as a flame-retardant coating agent described above. That is, in the method for producing a flame-retardant sheet material according to one embodiment, one surface of the sheet material is treated with the flame-retardant coating agent of the present disclosure, and then dried, thereby treating the surface of the sheet material and the flame-retardant coating agent. The method includes forming a film containing the flame retardant component (A) and the acrylic resin (B) on one or both of the interiors of the sheet material.

2.1 Presence or absence of dilution of flame-retardant coating agent When treating one side of a sheet material with a flame-retardant coating agent, the flame-retardant coating agent may be used as is or may be diluted as appropriate. .

2.2 Sheet Material Examples of the sheet material include base materials such as woven fabrics, knitted fabrics, and nonwoven fabrics; materials obtained by impregnating or coating resins on base materials such as woven fabrics, knitted fabrics, and nonwoven fabrics; and the like. The flame-retardant coating agent of the present disclosure imparts particularly excellent flame retardancy to a sheet material (artificial leather) in which a nonwoven fabric made from ultrafine thermoplastic synthetic fibers is impregnated with a polymeric elastic material. be able to. The sheet material may be perforated.

2.3 Specific example of a method for producing a flame-retardant sheet material As an example of a method for producing a flame-retardant sheet material, a method of treating artificial leather with a flame-retardant coating agent will be exemplified below.

Methods for treating artificial leather with flame-retardant coating agents include coating methods such as gravure coater, knife coater, roll coater, slit coater, comma coater, air knife coater, flow coater, rotary screen, brush, foaming, and spraying. can be mentioned.

After treating the artificial leather with a flame-retardant coating agent, the resulting flame-retardant artificial leather can be laminated or bonded.

The method of drying after treating one side of the artificial leather with a flame-retardant coating agent is not particularly limited, and includes, for example, dry drying using hot air; high-temperature pulcher steamer (H.T.S.); Wet drying using a pressure steamer (H.P.S.); a microwave irradiation dryer, etc. can be used. These drying methods can be used alone or in combination of two or more. Further, the drying temperature and drying time can be adjusted as appropriate depending on the flame retardant coating agent used, the amount applied, etc., but it is preferable that the drying temperature is 80° C. to 130° C. and the drying time is 1 minute to 30 minutes. More preferably, the drying temperature is 90° C. to 100° C. and the drying time is 2 minutes to 10 minutes. If the drying temperature is low or the drying time is short, sufficient drying may not be obtained, and if the drying temperature is high or the drying time is long, there is a concern that the fastness may decrease. By performing such drying, a flame-retardant coating can be formed on the treated surface of the artificial leather and/or in the sheet material.

The amount (DRY) of the flame retardant coating agent applied to the artificial leather is preferably 20 to 100 g/m ² in total of the active ingredients, more preferably 40 to 80 g/m ² . If the applied amount (DRY) is less than 20 g/m ² , there is a risk that flame retardancy will decrease, and if it exceeds 100 g/m ² , further improvement in flame retardance tends to be small.

Artificial leather treated with a flame-retardant coating agent is, for example, a nonwoven fabric made of ultrafine thermoplastic synthetic fibers with a single fiber fineness of 1 dtex or less, preferably 0.5 dtex or less, more preferably 0.3 dtex or less. The material may be impregnated with a polymeric elastomer such as polyurethane resin, or may be suede-like artificial leather with raised or raised naps formed on the surface. Further, it may be dyed with a disperse dye or the like.

Such artificial leathers include Ultrasuede, Ecsaine (Toray Industries, Ltd., registered trademark), Lamousse (Asahi Kasei Fibers Co., Ltd., registered trademark), Clarino (Kuraray Trading Co., Ltd., registered trademark), Patra, Bereza, Bel Ace, Berlia, and Air Cool. , Celsione (both FILWEL Co., Ltd.), Hyterax (Hitelux Co., Ltd.), Cordley (Teijin Ltd., registered trademark), Chamut (Koron Co., Ltd., registered trademark), Alcantara (Alcantara Co., Ltd., registered trademark), etc. .

The ultrafine synthetic fibers constituting the above-mentioned nonwoven fabric are preferably polyester synthetic fibers such as polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, and copolyester fibers containing these as main components, nylon 6, and nylon 6. , 6 is a polyamide-based synthetic fiber. Among these, polyethylene terephthalate is preferred because of its excellent dyeability, color fastness, and abrasion resistance.

Further, the above-mentioned polymeric elastic body is not limited to a specific material, and for example, acrylonitrile butadiene rubber, natural rubber, polyvinyl chloride, etc. can also be used.

Hereinafter, the flame-retardant coating agent and the method for producing the flame-retardant sheet material of the present disclosure will be further described with reference to Examples, but the technology of the present disclosure is not limited to the following Examples. In the technology of the present disclosure, various conditions may be adopted as long as the purpose is achieved without departing from the gist thereof.

1. Raw Materials The following raw materials were used in the Examples and Comparative Examples.

1.1 Flame retardant component (A)
・Phosphoramidate (a1):
DAIGUARD850: Phosphoramidate compound represented by the following formula (1) (average particle size 4 μm, manufactured by Daihachi Chemical Industry Co., Ltd.)
・Phosphorus compound (a2) whose solubility in water is 1.0% or less:
FR CROS 486: Silane-coated ammonium polyphosphate (Type II) (average particle size 18 μm, manufactured by CBC)
TERRAJU C-30: Melamine resin coated ammonium polyphosphate (Type II) (manufactured by CBC)
BCA: 9,10-dihydro-10-benzyl-9-oxa-10-phosphaphenanthrene-10-oxide (manufactured by Sanko Co., Ltd.)
ADEKA STAB FP-600: Bisphenol A bis(diphenyl phosphate) (oil, manufactured by ADEKA Co., Ltd.)
- Phosphorous compound (a2) with a solubility in water exceeding 1.0%:
FR CROS 484: Ammonium polyphosphate (Type II) (non-coated type, manufactured by CBC)
Apinone 303: Guanidine phosphate (manufactured by Sanwa Chemical Co., Ltd.)

1.2 Monomers constituting acrylic resin (B) Monomer (b1):
AN: Acrylonitrile (glass transition temperature 97°C)
Monomer (b2):
BA: butyl acrylate (glass transition temperature -55°C),
Other monomers (b4):
AA: acrylic acid (glass transition temperature 106°C),

1.3 Thickener (C)
Neosticker V-420: Alkaline thickening acrylic resin (manufactured by NICCA Chemical Co., Ltd., solid content 28% by mass)

1.4 Surfactant Nucor (registered trademark) 707SF: 50% by mass solution of polyoxyethylene polycyclic phenyl ether sulfate salt (manufactured by Nippon Nyukazai Co., Ltd.)
Nucor (registered trademark) 723: Polyoxyethylene polycyclic phenyl ether (manufactured by Nippon Nyukazai Co., Ltd.)
TSP20E (20 mole ethylene oxide adduct of tristyrenated phenol),
TSP10ES (sulfate ester salt of 10 mole ethylene oxide adduct of tristyrenated phenol, 50% by mass solution)

2. Synthesis of acrylic resin (B) [Synthesis example 1]
In a reaction apparatus, 220 parts by mass of ion-exchanged water, 15 parts by mass of Nucol 707SF, 15 parts by mass of Nucol 723, 46.72 parts by mass of acrylonitrile as monomer (b1), and butyl acrylate as monomer (b2) were added. 432.04 parts by mass and 6.25 parts by mass of acrylic acid as monomer (b3) were charged and mixed with stirring to prepare an emulsified mixture. After replacing the inside of the reaction apparatus with nitrogen gas, the internal temperature of the apparatus was heated to 80±5° C. while stirring. In a separate container, 204 parts by mass of ion-exchanged water, 5 parts by mass of Nucor 707SF, and 20 parts by mass of ammonium persulfate (10% by mass aqueous solution) were charged to prepare an initiator solution. Next, the initiator solution was added dropwise to the emulsified mixture over 3 hours. After the dropwise addition was completed, the reaction was continued for an additional 3 hours while maintaining the internal temperature of the above apparatus at 80±5°C. Thereafter, the internal temperature was cooled to 25±5°C. Next, it was neutralized with 6 parts by mass of 25% aqueous ammonia and adjusted to a resin concentration of 50% by mass to obtain an acrylic resin emulsion (B-1). The content (calculated value) of structural units derived from acrylonitriles in the acrylic resin (B) was 9.6%, and the glass transition temperature (Tg) (calculated value) was -36.7°C.

[Synthesis Examples 2 to 6]
Acrylic resin emulsions (B-2) to (B-7) according to Synthesis Examples 2 to 7 were obtained by performing the same operation as in Synthesis Example 1, except that each component was changed as shown in Table 1 below. Table 1 below shows the content (calculated value) of structural units derived from acrylonitrile and the glass transition temperature (Tg) (calculated value) of each resin.

3. Production of flame retardant coating agent [Example 5]
10 parts by mass of DAIGUARD 850 (average particle size 4 μm, manufactured by Daihachi Kagaku Kogyo Co., Ltd.) as phosphoroamidate (a1), 40 parts by mass of ion exchange water, 0.1 part by mass of TSP20E, Mix and homogenize TSP10ES with 0.1 part by mass, and use a bead mill (manufactured by IGARASHI KIKAI SEIZO CO.LTD, glass bead particle size 0.8-1.2 mm) to reduce the average particle size to 0.6 μm and the maximum particle size. The diameter was 30 μm. Next, 35 parts by mass of FR CROS486 as the phosphorus compound (a2), 10 parts by mass of the acrylic resin emulsion of Synthesis Example 1 as the acrylic resin (B), and Neosticker V- as the thickener (C) 420 and 5 parts by mass were homogenized and the viscosity was adjusted with 25% aqueous ammonia to obtain a flame retardant coating agent. The viscosity of this flame retardant coating agent was 8000 mPa·s, and the PVI value was 0.20.

[Examples 1 to 4, 6 to 20, Comparative Examples 1 to 7]
The procedure was the same as in Example 5, except that the compositions (parts by mass) were as shown in Tables 4 to 7 below, with a viscosity in the range of 6000 to 12000 mPa·s and a PVI value in the range of 0.19 to 0.21. A flame retardant coating agent was obtained in this manner.

4. Manufacture of flame-retardant artificial leather Apply the above-mentioned flame-retardant coating agent to the back side of the following sample fabric A or sample fabric B using a knife coater so that the coating amount (DRY) is 60±5 g/ ^m2 . A flame-retardant artificial leather cloth was prepared by applying the mixture using a flame-retardant artificial leather cloth and drying it at 100° C. for 3 minutes. The coating amount was calculated from [mass of flame-retardant artificial leather (g) - mass of artificial leather before coating (g)]÷area of artificial leather (m ² ).

Sample fabric A:
Polyester base fabric with a basis weight of 370 g/m ² and a thickness of 1 mm Suede-like plain patterned fabric Artificial leather impregnated with water-based polyurethane resin Black dyed fabric Sample fabric B:
Test fabric A was perforated using a perforation machine so that the perforation density was 30,000 holes/m ² , and the back side was made of 100% polyester tricot fabric (fabric weight 70 g/m ² , thickness 0.2 m, white). using

5. Evaluation of storage stability of flame retardant coating agent The storage stability of the above flame retardant coating agent was evaluated by the following method. 200 g of the flame-retardant coating agent was placed in a glass container with a diameter of 65 mm, and the container was covered with a lid and stored stationary in an environment of 20° C.±5° C. The state of the flame retardant coating agent after 6 months was checked and evaluated according to the following criteria.
○ (Pass): Uniform with no separation, sediment, floating matter, etc., and viscosity change is ±30% or less of the initial viscosity × (Fail): Is there any separation, sediment, floating matter, etc. , or even if the viscosity is uniform, the viscosity change exceeds ±30% of the initial viscosity.

6. Evaluation of flame-retardant artificial leather 6.1 Flammability The burning rate in the vertical direction of five test pieces was measured in accordance with FMVSS-302 (US Automobile Safety Standards). An "evaluation score" was specified for each of the five test pieces, and the lowest evaluation score was defined as the "overall evaluation score." Each evaluation point was specified according to Table 2 below. A case where the overall evaluation score was 3 or more was judged as passing. Note that Table 3 below shows an example of how to specify the "overall evaluation score". In Table 3 below, the evaluation scores for the first to fifth sheets are in random order. As shown in Table 3 below, if four of the five test pieces had an evaluation score of 5 and only one had an evaluation score of 4, the overall evaluation score was exceptionally set to 4.5.

6.2 Rubbing fastness Rubbing fastness was measured using a Gakushin type rubbing fastness tester (Daiei Kagaku Seiki Seisakusho) according to the method of JIS L 0849:2013. The larger the evaluation series, the better the fastness, and the case where the series was grade 3 or higher was judged as passing.

6.3 Color Migration A flame-retardant artificial leather cloth (sample cloth B) was kept suspended with a clip in an oven dryer set at 110° C. for 4 hours. After 4 hours, the degree of contamination from the artificial leather cloth to the tricot cloth was evaluated and determined. The hue change of the tricot fabric was determined using a stain gray scale (JIS L0805:2005). Grade 5 indicates the state in which there is no contamination and is good, and the design quality is maintained, and Grade 1 indicates the state in which the contamination is the strongest and the design quality is impaired. Grade 3 or above was considered passing.

7. Evaluation Results The evaluation results are shown in Tables 4 to 7 below.

The following can be seen from the results shown in Tables 4 to 7.
(1) Regarding the flame-retardant coating agents according to Comparative Examples 1 and 2, the flame-retardant component (A) did not contain phosphoroamidate (a1), and the perforated sample fabric B It was not possible to impart sufficient flame retardancy.
(2) Regarding the flame-retardant coating agents according to Comparative Examples 3 to 5, the acrylic resin (B) does not contain a structural unit derived from acrylonitriles (b1), and the perforated sample fabric B It was not possible to impart sufficient flame retardancy to the material.
(3) Regarding the flame retardant coating agent according to Comparative Example 6, the flame retardant component (A) does not contain phosphoroamidate (a1), does not contain acrylic resin (B), and has no perforation. It was not possible to impart sufficient flame retardancy to the processed sample fabric B.
(4) The flame-retardant coating agent according to Comparative Example 7 does not contain acrylic resin (B) and cannot impart sufficient flame retardancy to perforated sample fabric B. could not.
(5) On the other hand, the flame retardant coating agents according to Examples 1 to 22 were applied not only to the plain sample fabric A without perforation, but also to the perforated sample fabric B. It was also possible to impart sufficient flame retardancy to these materials. The flame-retardant coating agents according to Examples 1 to 22 contain a flame-retardant component (A) containing a phosphoroamidate (a1) represented by the above formula (1) and a structural unit derived from acrylonitriles (b1). It is considered that excellent flame retardancy could be imparted by including the acrylic resin (B).

By using the flame retardant coating agent of the present disclosure, a sheet material with excellent flame retardancy can be obtained. According to the flame retardant coating agent of the present disclosure, excellent flame retardance can be imparted even to perforated sheet materials. A sheet material imparted with flame retardance by the flame retardant coating agent of the present disclosure can be suitably used, for example, as a vehicle sheet material (for example, a car seat or a seat for a railway vehicle).

Claims (5)

A flame retardant component (A) containing a phosphoroamidate (a1) represented by the following formula (1),
an acrylic resin (B) containing a structural unit derived from acrylonitriles (b1);
flame-retardant coatings, including
The acrylonitrile (b1) is contained in an amount of 5 to 30% by mass based on the total amount of monomers constituting the acrylic resin (B),
The mass ratio of the flame retardant component (A) and the acrylic resin (B) is (A):(B) = 99:1 to 50:50.
The flame retardant coating agent according to claim 1. The flame retardant component (A) further contains a phosphorus compound (a2) other than the phosphoroamidate (a1),
The flame retardant coating agent according to claim 1 or 2. further comprising a thickener (C);
The flame retardant coating agent according to claim 1 or 2. After treating one side of the sheet material with the flame retardant coating agent according to claim 1 or 2, by drying, the retardant coating agent is applied to one or both of the surface of the sheet material and the inside of the sheet material. forming a film containing a combustion component (A) and the acrylic resin (B);
A method for producing a flame retardant sheet material, comprising: