Methods for manufacturing polymers, flame-retardant compositions, and polymers

Abstract

A polymer comprising the structural unit shown in general formula (I) below, a flame-retardant composition comprising the polymer, and a method for manufacturing the polymer. (In general formula (I), R 1 R represents any one selected from alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, and aralkyl groups having 7 to 18 carbon atoms. 2 Represents a hydrogen atom or a methyl group. R 3 R 4 Each of the following independently represents any one selected from alkyl, alkoxy, alkenyl, alkenyloxy, aralkyl, arylalkyl, arylalkoxy, aryl, and aryloxy groups having 1 to 6 carbon atoms. R 3 R 4 They can be bonded together, where n is an integer from 0 to 5.

Description

Technical Field

[0001] This invention relates to polymers comprising specific phosphorus-containing structural units, flame-retardant compositions comprising polymers, and methods for manufacturing polymers. Background Technology

[0002] Resins with methyl methacrylate (MMA) as their main component possess excellent properties such as high transparency and weather resistance, making them suitable for various applications. In recent years, the application of these resins in building materials that offer transparency and design flexibility has been increasing, but high flame retardancy is required in these applications.

[0003] As methods for imparting flame retardancy, the methods listed in Patent Documents 1 and 2 have been studied, for example. Specifically, Patent Document 1 discloses a methacrylic resin composition obtained by polymerizing a polymerizable composition containing a monomer composition, a phosphate ester, and an antioxidant, and describes a halophosphate ester or the like as the phosphate ester. Furthermore, Patent Document 2 discloses a flame-retardant acrylic artificial marble formed by curing a composition containing a resin component, an inorganic filler, a crosslinkable vinyl monomer, and an acrylate and / or a crosslinkable vinyl monomer, and describes aluminum hydroxide or the like as the inorganic filler.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2015-74740

[0007] Patent Document 2: Japanese Patent Application Publication No. 10-25146 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] While Patent Document 1 uses halogen-containing compounds, dehalogenation is desired from an environmental perspective, and there is a concern about the generation of toxic gases during combustion. Furthermore, adding inorganic flame retardants, as in Patent Document 2, results in turbidity and loss of transparency. Moreover, if a large amount of flame retardant is added to improve flame retardancy, the performance of the cast plastic sheet itself decreases, and it softens during combustion, thus posing a risk of inducing fires in the surrounding environment.

[0010] Therefore, the objective of this invention is to provide a polymer with excellent flame retardancy and which does not easily soften or lose physical properties when heated, a flame retardant composition, and a method for manufacturing the polymer.

[0011] Methods for solving problems

[0012] In order to solve the above-mentioned problems, the inventors conducted in-depth research and found that by including specific phosphorus-containing structural units in the polymer, it can achieve excellent flame retardancy and is less prone to softening or other physical property reduction when heated, thus completing the present invention.

[0013] That is, the present invention is as follows [1] to

[12] .

[0014] [1]. A polymer comprising the structural unit represented by the following general formula (I).

[0015] [Chemical Formula 1]

[0016]

[0017] (In general formula (I), R) 1 R represents any one selected from alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, and aralkyl groups having 7 to 18 carbon atoms. 2 Represents a hydrogen atom or a methyl group. R 3 R 4 Each of the following independently represents any one selected from alkyl, alkoxy, alkenyl, alkenyloxy, aralkyl, arylalkyl, arylalkoxy, aryl, and aryloxy groups having 1 to 6 carbon atoms. R 3 R 4 They can be bonded together, where n is an integer from 0 to 5.

[0018] [2]. According to the polymer described in [1], wherein R in the above general formula (I) is... 1 It is a methyl group.

[0019] [3]. The polymer according to [1] or [2], wherein n in the above general formula (I) is 1.

[0020] [4]. A compound represented by the following general formula (II).

[0021] [Chemical Formula 2]

[0022]

[0023] (In general formula (II), R) 21 R represents any one selected from alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, and aralkyl groups having 7 to 18 carbon atoms. 22 Represents a hydrogen atom or a methyl group. R 23 R 24Each of the following independently represents any one selected from alkyl, alkoxy, alkenyl, alkenyloxy, aralkyl, arylalkyl, arylalkoxy, aryl, and aryloxy groups having 1 to 6 carbon atoms. R 23 R 24 They can be bonded together, where p is an integer from 0 to 5.

[0024] [5]. According to the compound described in [4], wherein R in the above general formula (II) 21 It is a methyl group, and p is 1.

[0025] [6]. A flame-retardant composition comprising any one of the polymers described in [1] to [3].

[0026] [7]. A flame-retardant sheet or flame-retardant plate formed using any one of the polymers described in [1] to [3] or the flame-retardant composition described in [6].

[0027] [8]. A method for manufacturing a polymer, comprising a step of polymerizing a compound (A1) of the following general formula (III) and a polymerizable monomer (B) in the presence of at least one phosphite compound (C) selected from trivalent phosphonate compounds, phosphonate monoester compounds and phosphite diester compounds.

[0028] [Chemical Formula 3]

[0029]

[0030] (In general formula (III), R) 31 R represents any one selected from alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, and aralkyl groups having 7 to 18 carbon atoms. 32 This represents a hydrogen atom or a methyl group. q is an integer from 0 to 5.

[0031] [9]. The method for manufacturing the polymer according to [8], wherein q in the above general formula (III) is 0 or 1.

[0032]

[10] . The method for manufacturing the polymer according to [8] or [9], wherein the amount of the above-mentioned phosphite ester compound (C) added is 40 to 160 mol% relative to 100 mol% of the above-mentioned compound (A1).

[0033]

[11] . A composition comprising a compound (A1) of general formula (III), a polymerizable monomer (B), and at least one phosphite ester compound (C) selected from trivalent phosphonate compounds, phosphonite monoester compounds and phosphite diester compounds.

[0034] [Chemical Formula 4]

[0035]

[0036] (In general formula (III), R) 31 R represents any one selected from alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, and aralkyl groups having 7 to 18 carbon atoms. 32 This represents a hydrogen atom or a methyl group. q is an integer from 0 to 5.

[0037]

[12] . The composition according to

[11] , wherein the content of the phosphite ester compound (C) is 40 to 160 mol% relative to 100 mol% of the above compound (A1).

[0038] Invention Effects

[0039] According to the present invention, it is possible to provide a polymer with excellent flame retardancy and which does not easily suffer from softening or other physical property reduction when heated, a flame retardant composition, and a method for manufacturing the polymer. Detailed Implementation

[0040] The following description is based on an example of an embodiment of the present invention (hereinafter sometimes referred to as "this embodiment"). However, the embodiments shown below are illustrative examples used to embody the technical concept of the present invention, and the present invention is not limited to the following description.

[0041] Furthermore, while preferred embodiments are shown in this specification, combinations of two or more preferred embodiments are also preferred. Regarding the numerical ranges, when several numerical ranges exist, their lower and upper limits can be selectively combined as preferred embodiments.

[0042] It should be noted that in this specification, when a numerical range of "XX to YY" is specified, it means "above XX and below YY". Additionally, in this specification, "(meth)acrylate" refers to both methacrylate and acrylate.

[0043] The polymer of this embodiment has excellent flame retardancy by including specific phosphorus-containing structural units, and can suppress the reduction of physical properties such as softening upon heating.

[0044] Flame-retardant compositions containing the above-mentioned polymers exhibit low burning rates and produce virtually no burning drips. Furthermore, by using the above-mentioned polymers or flame-retardant compositions, flame-retardant sheets and flame-retardant boards with excellent flame-retardant properties can be provided.

[0045] Furthermore, the polymer can be easily obtained by employing the manufacturing method of the polymer that includes specific steps. Moreover, by using the compound represented by the general formula (II), excellent flame retardant properties can be achieved.

[0046] <Polymer>

[0047] The polymer of this embodiment comprises the structural unit shown in the following general formula (I).

[0048] [Chemical Formula 5]

[0049]

[0050] The reason why the polymer in this embodiment improves flame retardancy is still uncertain, but as one reason, it is believed that due to its high phosphorus-carbon interbonding, the amount of oxygen consumed during combustion is greater, thus improving flame retardancy.

[0051] In general formula (I), R 1 It means selected from any one of alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, and aralkyl groups having 7 to 18 carbon atoms.

[0052] In general formula (I), from the viewpoint of improving the physical properties of the obtained polymer, R 1 The alkyl group having 1 to 18 carbon atoms is preferably an alkyl group having 1 to 6 carbon atoms. Examples of alkyl groups having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. More preferably, it is an alkyl group having 1 to 3 carbon atoms, and even more preferably, it is methyl.

[0053] In general formula (I), from the viewpoint of improving the physical properties of the obtained polymer, R 1 The alkenyl group with 2 to 18 carbon atoms is preferably an alkenyl group with 2 to 10 carbon atoms, and more preferably an alkenyl group with 2 to 6 carbon atoms. Examples of alkenyl groups with 2 to 6 carbon atoms include vinyl, allyl, propenyl, isopropenyl, butenyl, isobutenyl, pentenyl, hexenyl (cis-3-hexenyl, etc.), cyclohexenyl, etc.

[0054] In general formula (I), R 1 The aralkyl group with 7 to 18 carbon atoms is preferably an aralkyl group with 7 to 14 carbon atoms. Examples of aralkyl groups with 7 to 14 carbon atoms include benzyl, 2-phenylethyl, 2-naphthylethyl, and diphenylmethyl.

[0055] In general formula (I), R 2 The symbol represents a hydrogen atom or a methyl group. From the point of view of polymerization operability, a methyl group is preferred.

[0056] In general formula (I), R 3 R 4 Each of the following independently represents any one selected from alkyl, alkoxy, alkenyl, alkenyloxy, aralkyl, arylalkyl, arylalkoxy, aryl, and aryloxy groups having 1 to 6 carbon atoms. R 3 R 4 They can bond with each other.

[0057] In general formula (I), as R 3 R 4 Examples of alkyl groups with 1 to 6 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

[0058] In general formula (I), as R 3 R 4 Examples of alkoxy groups with 1 to 6 carbon atoms include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, isopentoxy, neopentoxy, n-hexoxy, cyclopropoxy, cyclobutoxy, cyclopentoxy, and cyclohexoxy.

[0059] In general formula (I), as R 3 R 4 Examples of alkenyl groups with 2 to 6 carbon atoms include vinyl, allyl, propenyl, isopropenyl, butenyl, isobutenyl, pentenyl, hexenyl (cis-3-hexenyl, etc.), and cyclohexenyl.

[0060] In general formula (I), as R 3 R 4 Examples of olefins with 2 to 6 carbon atoms include ethyleneoxy, allyloxy, propenoxy, isopropenoxy, butenoxy, isobutenoxy, pentenoxy, hexenoxy (cis-3-hexenoxy, etc.), and cyclohexenoxy.

[0061] In general formula (I), as R 3 R 4 Examples of aralkyl groups with 7 to 12 carbon atoms include benzyl, 2-phenylethyl, and 2-phenylpropyl.

[0062] In general formula (I), as R 3 R 4 Examples of arylalkoxy groups with 7 to 12 carbon atoms include benzyloxy, 2-phenylethoxy, and 2-phenylpropoxy.

[0063] In general formula (I), as R 3 R 4 Examples of aryl groups representing 6 to 12 carbon atoms include phenyl, 2-methylphenyl, 2,4-dimethylphenyl, and 2-naphthyl.

[0064] In general formula (I), as R 3 R 4 Examples of aryloxy groups with 6 to 12 carbon atoms include phenoxy, 2-methylphenoxy, 2,4-dimethylphenoxy, and 2-naphthoxy.

[0065] From the perspective of improving flame retardancy, R 3 R 4 The preferred compounds are ethoxy, n-butoxy, phenoxy, and phenyl, with ethoxy and n-butoxy being more preferred.

[0066] In general formula (I), R is included. 3 R 4 The structure of the phosphorus-containing part can be exemplified by the following structures.

[0067] [Chemical Formula 6]

[0068]

[0069] From the viewpoint of improving the flame retardancy of the obtained polymer and flame retardant composition, R is included. 3 R 4 The phosphorus-containing portion preferably has the following structure.

[0070] [Chemical Formula 7]

[0071]

[0072] In general formula (I), n is any integer from 0 to 5, and from the viewpoint of improving the physical properties of the obtained polymer and flame retardant composition when heated, it is preferably 0 or 1, and more preferably 1.

[0073] The content of the structural unit shown in the above general formula (I) in the polymer of this embodiment is preferably 1 to 99% by mass, more preferably 5 to 80% by mass, even more preferably 10 to 70% by mass, even more preferably 10 to 60% by mass, and can also be 40 to 60% by mass. If the content of the structural unit shown in the above general formula (I) is within the above range, it is easy to improve the flame retardancy and further suppress the decrease in physical properties such as softening during heating.

[0074] (polymeric monomer (B))

[0075] The polymer of the present embodiment may include structural units other than the structural units represented by the general formula (I). For example, by including structural units derived from the polymerizable monomer (B), the polymer can exhibit properties such as decorativeness.

[0076] Examples of the polymerizable monomer (B) include vinyl monomers, (meth)acrylic acid alkyl esters, (meth)acrylic esters (Japanese: (メタ)アクリル酸エステル), (meth)acrylates (Japanese: (メタ)アクリレート), unsaturated dicarboxylic acids, etc. As the (meth)acrylic ester (Japanese: (メタ)アクリル酸エステル), for example, (meth)acrylic esters having a cyclic structure, a hydroxyl group, or a terminal epoxy group can be used. In addition, as the (meth)acrylate (Japanese: (メタ)アクリレート), for example, (meth)acrylates having an alkylene glycol structure, a silane, or a silyl terminal can be used.

[0077] Examples of the vinyl monomer include styrene, 2-methylstyrene, vinyl acetate, vinyl chloride, etc.

[0078] Examples of the (meth)acrylic acid alkyl ester include methyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, etc.

[0079] Examples of the (meth)acrylic ester having a cyclic structure include cyclohexyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, adamantyl (meth)acrylate, 3-hydroxyadamantyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, etc.

[0080] Examples of the (meth)acrylic ester having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, caprolactone-modified 2-hydroxyethyl (meth)acrylate, etc.

[0081] Examples of the (meth)acrylic ester having an epoxy group at the terminal include glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, etc.

[0082] Examples of the (meth)acrylic ester having an alkylene glycol structure include methoxydiethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, isooctoxydiethylene glycol (meth)acrylate, phenoxytriethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, etc.

[0083] Examples of (meth)acrylates that are silane or silyl-terminated include 2-trimethylsiloxyethyl (meth)acrylate.

[0084] Examples of unsaturated dicarboxylic acids include maleic anhydride and its derivatives.

[0085] Furthermore, as the polymerizable monomer (B), compounds having two or more polymerizable groups within the molecule can be used (excluding compounds (A1) described later). Examples of compounds having two or more polymerizable groups within the molecule include 2-propenyl (meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and neopentyl glycol di(meth)acrylate. 1,9-Nonadiol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, tricyclodecanediethanol di(meth)acrylate, glycerol di(meth)acrylate, di(meth)acrylate of hydrogenated bisphenol A or hydrogenated bisphenol F, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, trimethylolpropane tri(meth)acrylate, etc.

[0086] Alternatively, hydroxyl-containing poly(meth)acrylates can be used as the polymerizable monomer (B). Examples of hydroxyl-containing poly(meth)acrylates include glycerol di(meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol di(meth)acrylate, and dipentaerythritol monohydroxypenta(meth)acrylate.

[0087] From a processability and decorative point of view, methyl methacrylate and butyl methacrylate are preferred among these polymerizable monomers (B), and methyl methacrylate (i.e., Methyl(meta)acrylate) is more preferred. One of these polymerizable monomers (B) may be used alone, or two or more may be used in combination.

[0088] The content of structural units from polymeric monomer (B) in the polymer of this embodiment is not particularly limited, but is preferably 1 to 99% by mass, more preferably 20 to 95% by mass, even more preferably 30 to 90% by mass, and even more preferably 40 to 90% by mass. Alternatively, it can be 40 to 60% by mass. If the content of structural units from polymeric monomer (B) is within the above range, the flame retardancy can be improved, and the processability and decorative properties of the polymer can be improved.

[0089] For purposes such as operability and shortening polymerization time, these polymerizable monomers (B) can be polymerized to a certain extent before being mixed with other components and used in slurry form. This operation can be applied to all polymerizable monomers (B) or only to a portion of them.

[0090] <Polymer Manufacturing Methods (1)>

[0091] The polymer of this embodiment can be manufactured by applying known polymerization methods such as cationic polymerization, anionic polymerization, or free radical polymerization to polymerizable monomers that form the structural units shown in general formula (I).

[0092] (Compound (A))

[0093] As a polymerizable monomer forming the structural unit shown in general formula (I), a compound (A) shown in general formula (II) can be used. For example, a polymer manufacturing method (1) can be adopted by polymerizing a raw material composition containing compound (A) and the above-mentioned polymerizable monomer (B) as an arbitrary component by the above-mentioned known polymerization method.

[0094] By using compound (A), a polymer containing the structural unit shown in general formula (I) can be obtained. Furthermore, the polymer's molecular structure can contain a large number of phosphorus atoms, so that the dissolution and leakage (also known as exudation) of phosphorus-containing components caused by heating will not occur, and good performance can be maintained.

[0095] [Chemical Formula 8]

[0096]

[0097] In general formula (II), R 21 R 22 R 23 and R 24 R in the above general formula (I) respectively 1 R 2 R 3 and R 4 The same applies; repeated descriptions are omitted here.

[0098] R 21 R 21 R 22 R 23 and R 24 The preferred methods are respectively related to R in the above general formula (I). 1 R 2 R 3 and R 4 The same applies; repeated descriptions are omitted here.

[0099] In general formula (II), p is any integer from 0 to 5, and from the viewpoint of improving the physical properties of the obtained polymer and flame retardant composition when heated, it is preferably 0 or 1, and more preferably 1.

[0100] The aforementioned compound (A) can be synthesized, for example, by utilizing and applying well-known chemical reactions.

[0101] In the above-described method (1) for manufacturing the polymer, the amount of compound (A) added is not particularly limited. From the viewpoint of improving the flame retardancy of the flame-retardant composition described later, when the total amount of raw materials is set to 100 parts by mass, it is preferably 0.1 parts by mass or more, more preferably 1.0 parts by mass or more, and even more preferably 5.0 parts by mass or more. In addition, from the viewpoint of formability, when the total amount of raw materials is set to 100 parts by mass, the upper limit of the amount of compound (A) added is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, and can be 20 parts by mass or less.

[0102] <Polymer Manufacturing Methods (2)>

[0103] In addition to the polymer manufacturing method (1) described above, the polymer manufacturing method of this embodiment may also be a manufacturing method (2) that includes a step of polymerizing a compound (A1) of general formula (III) and a polymerizable monomer (B) in the presence of at least one phosphite ester compound (C) selected from trivalent phosphonate compounds, phosphonate monoester compounds and phosphite diester compounds.

[0104] As described above, the polymer of this embodiment can be manufactured by using a known polymerization method to produce a raw material composition containing compound (A). On the other hand, by employing the polymer manufacturing method (2), the polymer can be obtained without multi-stage processes. Furthermore, a molded article can be obtained by preparing a composition (raw material composition) containing a compound (A1) of general formula (III), a polymerizable monomer (B), and at least one phosphite ester compound (C) selected from trivalent phosphonate compounds, phosphonite monoester compounds, and phosphite diester compounds, and then injecting the above raw material composition into a mold for polymerization and curing.

[0105] (Compound (A1))

[0106] Compound (A1) is represented by the following general formula (III).

[0107] [Chemical Formula 9]

[0108]

[0109] In general formula (III), R 31 and R 32 R in the above general formula (I) respectively1 and R 2 The same applies; repeated descriptions are omitted here.

[0110] From the perspective of aggregation operations, R 31 Methyl group is preferred.

[0111] R 32 The symbol represents a hydrogen atom or a methyl group. From the point of view of polymerization operability, a methyl group is preferred.

[0112] In general formula (III), q is any integer from 0 to 5. From the viewpoint of improving the physical properties of the obtained polymer and flame retardant composition when heated, q is preferably 0 or 1, and more preferably 1.

[0113] In the polymer manufacturing method (2), the amount of compound (A1) added is not particularly limited. On the other hand, from the viewpoint of imparting more sufficient flame retardancy to the polymer and the flame-retardant composition, when the total amount of raw materials is set to 100 parts by mass, the amount of compound (A1) added is preferably 0.1 parts by mass or more, more preferably 3.0 parts by mass or more, and can also be 10 parts by mass or more, or 20 parts by mass or more. There is no particular upper limit to the amount of compound (A1) added. On the other hand, from the viewpoint of molding processability, when the total amount of raw materials is set to 100 parts by mass, the amount of compound (A1) added is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and more preferably 30 parts by mass or less.

[0114] It should be noted that the preferred method for adding the above-mentioned compound (A1) can be interpreted as the preferred method for the content of compound (A1) relative to 100 parts by mass of the total amount of the raw material composition.

[0115] (polymeric monomer (B))

[0116] In the polymer manufacturing method (2), the polymerizable monomer (B) used is the same as the polymerizable monomer (B) described above, and repeated descriptions are omitted here.

[0117] (Phosphite ester compounds (C))

[0118] Examples of trivalent phosphonate compounds include diphenylphosphine oxide, diethylphosphine oxide, and dibutylphosphine oxide.

[0119] Examples of phosphonic acid monoester compounds include ethyl phenylphosphonate, butyl phenylphosphonate, phenyl phenylphosphonate, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0120] Examples of phosphite diester compounds include diethyl phosphite, diisopropyl phosphite, dibutyl phosphite, 1,3-dioxa-2-phosphacyclohexane-2-oxide, 1,3-dioxa-5,5-dimethyl-2-phosphacyclohexane-2-oxide, diphenyl phosphite, bis(2,4-dimethyl)phenyl phosphite, and 1,2,3,4-tetrahydro-1,3-dioxa-2-phosphanaphthalene-2-oxide.

[0121] These phosphite ester compounds (C) can be used alone or in combination of two or more.

[0122] From the viewpoint of raw material mixability and flame retardancy, the preferred phosphite ester compound (C) is diethyl phosphite, dibutyl phosphite, diphenyl phosphite, or 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and more preferably diethyl phosphite, dibutyl phosphite, or 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0123] The amount of phosphite ester compound (C) added is not particularly limited. However, from the viewpoint of imparting more sufficient flame retardancy to the polymer and the flame-retardant composition, when the total amount of raw materials is set to 100 parts by mass, the amount of phosphite ester compound (C) added is preferably 0.1 parts by mass or more, more preferably 3.0 parts by mass or more, and can also be 10 parts by mass or more, or 15 parts by mass or more. There is no particular upper limit to the amount of phosphite ester compound (C) added. However, from the viewpoint of processability, when the total amount of raw materials is set to 100 parts by mass, the amount of phosphite ester compound (C) added is preferably 30 parts by mass or less, more preferably 25 parts by mass or less.

[0124] It should be noted that the preferred method for adding the above-mentioned phosphite ester compound (C) can be interpreted as the preferred method for the content of phosphite ester compound (C) relative to 100 parts by mass of the total amount of the raw material composition.

[0125] Furthermore, the amount of phosphite ester compound (C) added relative to 100 mol% of the aforementioned compound (A1) is not particularly limited. On the other hand, from the viewpoint of further improving flame retardancy, it is preferable to add 40 mol% or more, more preferably 60 mol% or more, and even more preferably 90 mol% or more. In addition, from the viewpoint of easily balancing the improvement of flame retardancy and avoiding the dissolution and leakage of phosphite ester compound (C), the amount of phosphite ester compound (C) added relative to 100 mol% of the aforementioned compound (A1) is preferably 160 mol% or less, more preferably 130 mol% or less, and even more preferably 110 mol% or less.

[0126] It should be noted that the preferred method of adding 100 mol% of phosphite ester compound (C) relative to the above-mentioned compound (A1) can be interpreted as the preferred method of the content of phosphite ester compound (C) in the raw material composition relative to 100 mol% of compound (A1).

[0127] (Free radical polymerization initiator (D))

[0128] The polymer manufacturing method (2) can use a free radical polymerization initiator (D). There are no particular restrictions on the type of free radical polymerization initiator (D), and it can be appropriately selected according to the type of compound (A1), polymerizable monomer (B), phosphite ester compound (C), etc. Examples of free radical polymerization initiators (D) include thermal free radical polymerization initiators that generate free radicals using heat, and photofree radical polymerization initiators that generate free radicals using light.

[0129] Examples of organic peroxides that can be used as initiators for thermal free radical polymerization include azo compounds such as 2,2'-azobis(2,4-dimethylpentanonitrile) (AIBN) and 2,2'-azobis(2,4-dimethylpentanonitrile) (ADVN); diacyl peroxides such as benzoyl peroxide; peroxide esters such as tert-butyl peroxide; hydroperoxides such as cumene hydroperoxide; dialkyl peroxides such as diisopropylbenzene peroxide; ketone peroxides such as methyl ethyl ketone peroxide and acetylacetone peroxide; peroxide ketals; alkyl peresters; and percarbonate systems.

[0130] Commercially available products can be used as photoradical polymerization initiators. Examples include Irgacure (registered trademark, hereinafter the same) 651, Irgacure 184, Irgacure 2959, Irgacure 127, Irgacure 907, Irgacure 369, Irgacure 379, Irgacure 819, Irgacure 784, Irgacure OXE01, Irgacure OXE02, and Irgacure 754 (all manufactured by BASF).

[0131] Free radical polymerization initiator (D) can be used alone or in combination of two or more.

[0132] The amount of free radical polymerization initiator (D) added is not particularly limited. In order to obtain a polymer with sufficient degree of polymerization, when the total amount of raw materials is set to 100 parts by mass, it is preferably 0.001 parts by mass or more, more preferably 0.001 parts by mass or more and 3 parts by mass or less.

[0133] The polymer manufacturing method (2) can be implemented using a mold. By using a mold for polymerization and curing, the polymer can be given the shape of the mold, resulting in a cured polymer with excellent flame retardancy. Examples of molds include a mold consisting of a pair of plate-like bodies such as tempered glass, chrome-plated plate, or stainless steel plate and a gasket such as soft vinyl chloride resin, and a mold consisting of the opposing faces of a pair of annular belts traveling in the same direction at the same speed and gaskets on both sides of the annular belts traveling at the same speed as the two annular belts.

[0134] Furthermore, by injecting a composition containing various additives that can be used in the flame-retardant composition described later into a mold, in addition to the raw material composition of the polymer, a cured product containing the flame-retardant composition of the polymer can be obtained in a state that imparts the shape of the mold.

[0135] Regarding the polymerization temperature, from the perspective of improving transparency and polymerization rate, it is preferable to set it to two stages: a primary curing at 40–90°C and a secondary curing at 110–140°C.

[0136] <Flame-retardant compositions>

[0137] The flame-retardant composition of this embodiment contains a polymer comprising the structural unit shown in the general formula (I) above. Since the polymer contains phosphorus atoms in its molecular structure, there is no dissolution or leakage of phosphorus-containing components caused by heating, and the flame-retardant composition can maintain good flame retardancy.

[0138] The proportion of the aforementioned polymer contained in the flame-retardant composition is not particularly limited, but from the viewpoint of flame retardancy, it is preferably 0.1 parts by mass or more, more preferably 1.0 parts by mass or more, relative to 100 parts by mass of the flame-retardant composition. The upper limit of the proportion of the aforementioned polymer contained in the flame-retardant composition is not particularly limited, but considering processability, it is preferably 50 parts by mass or less, more preferably 30 parts by mass or less.

[0139] (Various additives)

[0140] Flame retardant compositions may contain various additives such as diluents, pigments, dyes, fillers, UV absorbers, thickeners, low-shrinkage agents, anti-aging agents, plasticizers, aggregates, flame retardants, stabilizers, fiber reinforcement materials, antioxidants, leveling agents, and anti-sagging agents.

[0141] <Application>

[0142] The use of the polymer and flame-retardant composition of this embodiment is not particularly limited, and it can be particularly suitable for flame-retardant sheets, polymer boards, molded boards, coatings, adhesives, bonding agents, etc.

[0143] As a preferred embodiment of the use of the polymer and flame-retardant composition, flame-retardant sheets or flame-retardant plates are provided. Flame-retardant sheets or plates made using the polymer and flame-retardant composition are superior in that they do not contain harmful halogen atoms and are less prone to degradation of physical properties such as dripping when heated.

[0144] The aforementioned flame-retardant sheets and flame-retardant plates can be processed into arbitrary three-dimensional shapes through secondary forming using known methods. Examples of secondary forming methods include vacuum forming and pneumatic forming.

[0145] After preheating the flame-retardant sheet or plate to a suitable temperature using a heating furnace or similar means, it is then shaped into the desired form by using vacuum, compression, air, mechanical pressure, or a combination thereof along a mold.

[0146] Example

[0147] The present invention will be described in detail below through embodiments, but the present invention is not limited to these embodiments.

[0148] <Synthesis of Compound (A) 1>

[0149] The compounds shown in the following reaction formulas were synthesized by the synthesis methods described in [Manufacturing Examples 1] to [Manufacturing Examples 4] and [Example 1], and compound (A) (the compound shown in chemical formula A2 in the following reaction formulas) was synthesized by general formula (II).

[0150] [Chemical Formula 10]

[0151]

[0152] [Manufacturing Example 1] Synthesis of Compound (a1)

[0153] In a nitrogen-purified four-necked flask, 19.23 g (150.0 mmol) of ethyl 3-methyl-2-butenoate and 150 mL of carbon tetrachloride were added, and the mixture was heated to reflux. 29.3 g (165.0 mmol) of N-bromosuccinimide and 126 mg (0.75 mmol) of azobisisobutyronitrile were added, and the mixture was stirred for 30 minutes. An additional 126 mg of azobisisobutyronitrile was added, and the mixture was stirred for another 30 minutes and then cooled. The insoluble matter was filtered off, and the resulting reaction solution was concentrated to give a solution containing compound (a1).

[0154] [Manufacturing Example 2] Synthesis of Compound (a2)

[0155] A concentrated solution containing compound (a1) obtained in Preparation Example 1 (equivalent to 150.0 mmol of compound (a1)) was added to a nitrogen-purified four-necked flask and dissolved in 75 mL of toluene. 38.9 mL (225.0 mmol) of triethyl phosphite was added, and the mixture was stirred at 95 °C for 12 hours. The resulting reaction solution was concentrated and purified by silica gel column chromatography to give 14.7 g (55.7 mmol, 37.1 mol%) of compound (a2).

[0156] [Manufacturing Example 3] Synthesis of Compound (a3)

[0157] 14.6 g (55.2 mmol) of compound (a2) obtained in Preparation Example 2 and 80 mL of ethanol were added to a nitrogen-purified four-necked flask and dissolved. 2.9 g of 20% Pd / C catalyst was added, and the atmosphere was replaced with hydrogen. The mixture was stirred for 12 hours. The resulting reaction solution was filtered through diatomaceous earth and purified by silica gel column chromatography to give 13.7 g (51.9 mmol, 93.2 mol%) of compound (a3).

[0158] [Manufacturing Example 4] Synthesis of Compound (a4)

[0159] In a nitrogen-purified four-necked flask, 17.4 g (65.3 mmol) of compound (a3) ​​obtained in Preparation Example 3, 330 mL of dichloromethane, and 295 mL (295 mmol) of 1 M diisobutylaluminum hydride solution were added and dissolved. 50 mL of water and 35 mL of 6 M hydrochloric acid were added, and the mixture was stirred at temperatures below 30°C. An additional 35 mL of 6 M hydrochloric acid was added. The organic layer was separated, extracted with ethyl acetate, and dried over sodium sulfate. The organic layer was purified by silica gel column chromatography to give 12.6 g of an oily product.

[0160] The above oily product was replaced with a nitrogen atmosphere and dissolved in 40 mL of methanol and 40 mL of tetrahydrofuran. After stirring at room temperature (25 °C), 3.6 mL of glacial acetic acid was added. The reaction solution was concentrated and extracted with dichloromethane. The residue was purified by silica gel column chromatography to give 10.7 g (42.9 mmol, 65.7 mol%) of compound (a4).

[0161] [Example 1] Synthesis of compound (A)

[0162] In a nitrogen-purified four-necked flask, 9.0 g (40.0 mmol) of compound (a4) obtained in Preparation Example 4, 80 mL of dichloromethane, 25.1 mL (180 mmol) of diisopropylethylamine, and 15.6 mL (180 mmol) of methacryloyl chloride were added, and the mixture was stirred at room temperature (25 °C) for 2 hours. 40 mL of 1 M citric acid aqueous solution and 80 mL of ethyl acetate were added to the reaction mixture, and the organic layer was extracted. After drying with sodium sulfate, the mixture was purified by silica gel column chromatography to give 7.0 g (65.7 mol%) of compound (A) represented by the above chemical formula A2.

[0163] <Synthesis of Compound (A) 2>

[0164] Using the synthesis methods of [Manufacturing Example 5] and [Example 2], the compounds shown in the following reaction formulas were synthesized, and the compound (A) shown in the general formula (IJ) (the compound shown in the chemical formula A3 in the following reaction formulas) was synthesized.

[0165] [Chemical Formula 11]

[0166]

[0167] [Manufacturing Example 5] Synthesis of Compound (a5)

[0168] In a nitrogen-purified four-necked flask, 500 g of toluene, 29.9 g (347 mmol) of 3-methyl-3-buten-1-ol, 79.1 g (364 mmol) of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and 3.75 g (17.3 mmol) of PERBUTYL (registered trademark) O (manufactured by Nippon Oil Co., Ltd.) were added. The mixture was heated to 95°C and stirred for 3.5 hours. After cooling, the resulting reaction solution was concentrated to give 159.7 g of a solution containing compound (a5).

[0169] [Example 2] Synthesis of compound (A)

[0170] In a nitrogen-purified four-necked flask, 159.7 g of a solution containing compound (a5) obtained in Preparation Example 5, 500 g of acetonitrile, and 58.1 g (575 mmol) of triethylamine were added. The mixture was cooled in an ice bath, and 44.1 g (418 mmol) of methacrylamide chloride was added dropwise at a rate that maintained the reaction temperature within the range of 5°C to 8°C. After the addition was complete, the mixture was stirred at room temperature for 2 hours. 200 g of deionized water and 0.4 g (3.3 mmol) of 4-dimethylaminopyridine were added to the reaction mixture, and the organic layer was extracted with ethyl acetate. After drying with sodium sulfate, the mixture was purified by silica gel column chromatography to give 118.0 g (319 mmol, 91.8 mol%) of compound (A) represented by the above chemical formula A3.

[0171] <Preparation of Polymer Plates and Experimental Sheets>

[0172] [Examples 3-11], [Comparative Examples 1 and 2]

[0173] Add the mixture of raw materials from Table 1 to a beaker containing a stir bar, and stir until completely dissolved to prepare a raw material composition (raw material liquid). Inject the above raw material liquid into a compartment consisting of two stainless steel plates (2 mm thick, 20 cm square) and a polyvinyl chloride resin gasket, and polymerize in a 60°C water bath for 6 hours, followed by polymerization in a 130°C oven for 2 hours to obtain a sheet with a thickness of 3.2 mm.

[0174] Test pieces with a length of 127 mm × width of 13 mm × thickness of 3.2 mm were cut from the obtained sheet. These test pieces were then used to conduct the following combustion tests for evaluation. The evaluation results of the combustion tests are shown in Table 1.

[0175] It should be noted that Examples 3 and 10 are examples of manufacturing method (1) of the polymer described above, while Examples 4 to 9 and 11 are examples of manufacturing method (2) of the polymer described above.

[0176] <Evaluation (Combustion Test)>

[0177] [Burn speed]

[0178] A 3.2 mm thick test piece was left to stand at 23°C and 50% RH for 18 hours. Following JIS K 6911:1995A, the horizontally positioned test piece was exposed to a flame for 30 seconds using a burner. The average value of three test pieces was taken, and the flame retardancy was evaluated by their respective burning speeds (mm / s). The lower the burning speed, the better the flame retardancy.

[0179] [Drip Test]

[0180] In the above combustion speed test, it is determined whether dripping or sag occurs from the test piece during combustion. If no dripping or sag occurs, it is rated as "A"; if dripping occurs, it is rated as "B".

[0181] [Exudation]

[0182] Observe the surface of the test piece prepared as described above, and determine whether there is any leaching (dissolution, leakage) of phosphorus-containing components by sight and touch. If leaching cannot be confirmed, it is evaluated as "none"; if it can be confirmed, it is evaluated as "present".

[0183] [Flame-retardant carbonized layer]

[0184] Visually inspect the test piece after the above combustion test. If the formation of a black flame-retardant carbonized layer caused by phosphorus components can be confirmed, it is evaluated as "present". If it cannot be confirmed, it is evaluated as "absent".

[0185] [Table 1]

[0186]

[0187] <Ingredients>

[0188] The raw materials listed in Table 1 are as follows.

[0189] <Compound (A)>

[0190] • Chemical Formula A2: The compound represented by Chemical Formula A2 obtained by the synthesis methods described in [Manufacturing Examples 1] to [Manufacturing Examples 4] and [Example 1] above.

[0191] • Chemical Formula A3: The compound represented by Chemical Formula A3 obtained by the synthesis methods described in [Manufacturing Example 5] and [Example 2] above.

[0192] <Compound (A1))

[0193] • 3-Methyl-3-butenyl methacrylate (manufactured by Kuraray Co., Ltd.)

[0194] <Polymerizable Monomer (B)>

[0195] ·MMA: Methyl methacrylate (manufactured by Kuraray Co., Ltd.)

[0196] <Phosphite ester compounds (C)>

[0197] • DOPO: 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0198] • Diethyl phosphite: Diethyl phosphite (manufactured by Fujifilm and Wako Pure Chemical Industries, Ltd.)

[0199] • Dibutyl phosphite: Dibutyl phosphite (manufactured by Fujifilm and Wako Pure Chemical Industries, Ltd.)

[0200] <Free Radical Polymerization Initiator (D)>

[0201] V-65: 2,2'-Azobis(2,4-dimethylvalerate) (manufactured by Fujifilm and Wako Pure Chemical Industries, Ltd.)

[0202] • PerHexa (registered trademark) C: 1,1-Di(tert-butylperoxide)cyclohexane (manufactured by Nippon Oil Co., Ltd.)

[0203] According to Examples 3 and 10 in Table 1, the sheets using polymers comprising the structural units shown in general formula (I) exhibited low burning rates, no dripping, and a flame-retardant carbonized layer on the surface, with no oozing observed. Therefore, Examples 3 and 10 demonstrate excellent flame retardancy.

[0204] In addition, as in Examples 4-9 and 11, the polymers manufactured by polymer manufacturing method (2) also exhibit excellent flame retardancy, similar to Examples 3 and 10.

[0205] On the other hand, the sheet of Comparative Example 1, which used a polymer without the structural unit shown in general formula (I), had a high burning rate, and no flame-retardant carbonized layer was observed. Furthermore, the sheet of Comparative Example 2, which used a polymer without the structural unit shown in general formula (I), dripped. Therefore, Comparative Examples 1 and 2 failed to exhibit excellent flame retardancy.

[0206] Industrial availability

[0207] The polymers of the present invention exhibit excellent flame retardancy and are not prone to softening or other property degradation upon heating. Therefore, the polymers of the present invention and flame-retardant compositions comprising the polymers can be used in applications requiring flame retardancy, and are particularly suitable for use in flame-retardant sheets, flame-retardant boards, flame-retardant coatings and coatings, flame-retardant adhesives, flame-retardant binders, flame-retardant fibers, etc.

Claims

1. A polymer comprising structural units represented by the following general formula (I), In general formula (I), R 1 R represents any one selected from alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, and aralkyl groups having 7 to 18 carbon atoms. 2 R represents a hydrogen atom or a methyl group. 3 R 4 Each independently represents any one selected from alkyl, alkoxy, alkenyl, alkenyloxy, aralkyl, arylalkyl, arylalkoxy, aryl, and aryloxy groups having 1 to 6 carbon atoms, R 3 R 4 Choose any two bonds to each other, where n is 1.

2. The polymer according to claim 1, wherein, R in the general formula (I) 1 It is a methyl group.

3. A compound represented by the following general formula (II), In general formula (II), R 21 R represents any one selected from alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, and aralkyl groups having 7 to 18 carbon atoms. 22 R represents a hydrogen atom or a methyl group. 23 R 24 Each independently represents any one selected from alkyl, alkoxy, alkenyl, alkenyloxy, aralkyl, arylalkyl, arylalkoxy, aryl, and aryloxy groups having 1 to 6 carbon atoms, R 23 R 24 Choose any two bonds to each other, with p = 1.

4. The compound according to claim 3, wherein, R in general formula (II) 21 It is a methyl group.

5. A flame-retardant composition comprising the polymer of claim 1 or 2.

6. A flame-retardant sheet or flame-retardant plate made using the polymer of claim 1 or 2 or the flame-retardant composition of claim 5.

7. A method for manufacturing a polymer, comprising the step of polymerizing a compound (A1) of general formula (III) and a polymerizable monomer (B) in the presence of at least one phosphite ester compound (C) selected from trivalent phosphonate compounds, phosphonite monoester compounds, and phosphite diester compounds. In general formula (III), R 31 R represents any one selected from alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, and aralkyl groups having 7 to 18 carbon atoms. 32 This represents a hydrogen atom or a methyl group, where q is 1.

8. The method for manufacturing the polymer according to claim 7, wherein, The amount of the phosphite ester compound (C) added is 40 mol% to 160 mol% relative to 100 mol% of the compound (A1).

9. A composition comprising a compound (A1) of general formula (III), a polymerizable monomer (B), and at least one phosphite ester compound (C) selected from trivalent phosphonate compounds, phosphonite monoester compounds, and phosphite diester compounds. In general formula (III), R 31 R represents any one selected from alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, and aralkyl groups having 7 to 18 carbon atoms. 32 This represents a hydrogen atom or a methyl group, where q is 1.

10. The composition according to claim 9, wherein, The content of the phosphite ester compound (C) is 40 mol% to 160 mol% relative to 100 mol% of the compound (A1).

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