JP7352906B2 - Phosphate ester flame retardant, (meth)acrylic resin composition and resin molding - Google Patents

Description

The present invention relates to a phosphate ester flame retardant, a (meth)acrylic resin composition, and a resin molded article.

(Meth)acrylic resin, whose main component is methyl methacrylate, has excellent transparency, heat resistance, and weather resistance, and has well-balanced performance in resin physical properties such as mechanical strength, thermal properties, and moldability. have. For this reason, it is used in many applications such as lighting materials, optical materials, signboards, displays, decorative components, architectural components, and face plates of electronic devices.In recent years, these applications have been used to prevent fire spread and evacuation time in the event of a fire. (Meth)acrylic resins with excellent flame retardancy are needed to create such materials.

In particular, for canopy signboards at gas stations, it has flame retardancy that is better than self-extinguishing according to JIS K6911 flame resistance test method A, as well as heat resistance and mechanical strength that can withstand outdoor use (meta). Acrylic resin is needed.

In addition, for internal parts of electronic devices such as computer cases and heat exhaust ducts, the vertical combustion test specified by UL94, which requires higher flame retardancy than the above-mentioned JIS K6911 flame resistance test method A, has been tested. In addition to having flame retardancy of , V-0, high stability against heat and external forces is required, and (meth)acrylic resins with excellent heat resistance and mechanical strength are required.

As a technique for imparting flame retardance and heat resistance to (meth)acrylic resin, for example, Patent Document 1 describes a flame retardant resin made of methacrylic resin containing a heat resistance improving monomer and a halogenated phosphate ester. A methacrylic resin plate has been proposed, and dicyclopentanyl (meth)acrylate has been disclosed as a heat resistance improving monomer.

Further, Patent Document 2 proposes a flame-retardant methacrylic resin board containing a (meth)acrylic polymer containing methyl methacrylate and isobornyl (meth)acrylate, and a phosphorus compound as a flame retardant.

In addition, Patent Document 3 proposes a flame-retardant methacrylic resin board that uses a specific structure as a phosphoric ester, and uses a mixture of polymerization degrees n of 1 and 2 as a phosphoric ester, that is, an average polymerization Phosphate esters having a degree of less than 2 are disclosed.
Patent Document 4 discloses a flame retardant containing a polyphosphate type organic phosphorus compound having a reduced content of an organic phosphorus compound having a hydroxyl group and a phosphate ester monomer.
Further, Patent Document 5 discloses a halogen-containing system made by reacting phosphorus oxychloride and alkylene glycol at a molar ratio of 1.5 to 3.0:1.0, and reacting the reaction product with alkylene oxide. A method for producing a condensed phosphate ester is disclosed.

Japanese Patent Application Publication No. 2011-046835 International Publication No. 2016/063898 JP2003-277568A International Publication No. 2016/104263 Japanese Patent Application Publication No. 8-259577

However, in the methacrylic resin board described in Patent Document 1, it is necessary to add a large amount of flame retardant in order to obtain flame retardance that makes it non-flammable in the flame resistance test method A of JIS K6911-1979, and the heat resistance improvement unit Due to the low content of methacrylic resin, the heat resistance of the methacrylic resin plate was insufficient, and it could not be used in applications requiring heat resistance of 90° C. or higher at a deflection temperature under load (HDT). In addition, the flame retardance was insufficient for use in electronic device parts that require V-0 in the vertical combustion test specified by UL94.
In addition, in the methacrylic resin board described in Patent Document 2, when the amount of isobornyl (meth)acrylate added to improve flame retardance and heat resistance is increased, the mechanical strength tends to decrease, and some applications In some cases, it was not possible to meet the higher stability required for external forces. Therefore, it has been difficult to obtain a (meth)acrylic resin plate that has both high flame retardancy, heat resistance, and sufficient mechanical strength.
Furthermore, the methacrylic resin plate described in Patent Document 3 still did not have sufficient heat resistance.
Furthermore, the flame retardants of Patent Documents 4 and 5 still have insufficient flame retardancy and heat resistance.
Under these circumstances, resin moldings with excellent heat resistance, flame retardance, and mechanical strength, (meth)acrylic resin compositions for producing the resin moldings, and (meth)acrylic resins are needed. There was a need for flame retardants for inclusion in compositions.

The present invention provides a phosphate ester flame retardant capable of imparting excellent flame retardancy, heat resistance, and mechanical strength to a resin molded article, a (meth)acrylic resin composition containing the flame retardant, and the aforementioned flame retardant. A resin molded article made of a (meth)acrylic resin composition can be provided.

［式（Ｉ）中、Ｒ^１、Ｒ^２、及びＲ^３は、それぞれ独立に、水素原子、炭素数１～４のアルキル基又は炭素数１～４のクロロアルキル基を示す。Ｙは－（ＣＨ_２）_ｘ－又は－ＣＨ_２ＣＨ_２－（ＯＣＨ_２ＣＨ_２）_ｚＯＣＨ_２ＣＨ_２－を示し、ｘは３～６の整数であり、ｚは０～３の整数であり、ｎは０～８の整数である。
ゲルパーミエーションクロマトグラフィー（ＧＰＣ）で測定したときに、前記一般式（Ｉ）におけるｎ＝０～８の各化合物の含有量から算出される平均重合度Ｎが２．１～３．３の範囲にある。］
［２］ 前記一般式（Ｉ）で表される化合物において、平均重合度Ｎが２．３以上である、［１］に記載のリン酸エステル系難燃剤（Ｃ１）。
［３］ 前記一般式（Ｉ）で表される化合物において、平均重合度Ｎが３．１以下である、［１］又は［２］に記載のリン酸エステル系難燃剤（Ｃ１）。
［４］ 前記一般式（Ｉ）で表される化合物において、２５℃における粘度が１５００～４５００ｍＰａ・ｓである、［１］～［３］のいずれか一項に記載のリン酸エステル系難燃剤（Ｃ１）。
［５］ 前記一般式（Ｉ）において、Ｒ^１、Ｒ^２、及びＲ^３がそれぞれ独立に水素原子、メチル、エチル、クロロメチル又はクロロエチル基であり、Ｙが１，２－プロピレン基、１，３－プロピレン基、－ＣＨ₂ＣＨ₂ＯＣＨ₂ＣＨ₂－又は－ＣＨ₂ＣＨ₂ＯＣＨ₂ＣＨ₂ＯＣＨ₂ＣＨ₂－である、［１］～［４］のいずれか一項に記載のリン酸エステル系難燃剤（Ｃ１）。
［６］ （メタ）アクリル系樹脂組成物用難燃剤である、［１］～［５］のいずれか一項に記載のリン酸エステル系難燃剤（Ｃ１）。
［７］ 下記一般式（Ｉ）で表される化合物を含有し、
２５℃における粘度が１５００～３７００ｍＰａ・ｓである、リン酸エステル系難燃剤（Ｃ２）。

［式（Ｉ）中、Ｒ^１、Ｒ^２、及びＲ^３は、それぞれ独立に、水素原子、炭素数１～４のアルキル基又は炭素数１～４のクロロアルキル基を示す。Ｙは－（ＣＨ_２）_ｘ－又は－ＣＨ_２ＣＨ_２－（ＯＣＨ_２ＣＨ_２）_ｚＯＣＨ_２ＣＨ_２－を示し、ｘは３～６の整数であり、ｚは０～３の整数であり、ｎは０～８の整数である。］
［８］ 前記一般式（Ｉ）において、Ｒ^１、Ｒ^２、及びＲ^３がそれぞれ独立に水素原子、メチル、エチル、クロロメチル又はクロロエチル基であり、Ｙが１，２－プロピレン基、１，３－プロピレン基、－ＣＨ₂ＣＨ₂ＯＣＨ₂ＣＨ₂－又は－ＣＨ₂ＣＨ₂ＯＣＨ₂ＣＨ₂ＯＣＨ₂ＣＨ₂－である、［７］に記載のリン酸エステル系難燃剤（Ｃ２）。
［９］ （メタ）アクリル系樹脂組成物用難燃剤である、［７］又は［８］に記載のリン酸エステル系難燃剤（Ｃ２）。
［１０］ （メタ）アクリル系重合体（Ｐ）と、［１］～［６］のリン酸エステル系難燃剤（Ｃ１）及び［７］～［９］のリン酸エステル系難燃剤（Ｃ２）からなる群から選択される少なくとも１種と、を含有する、（メタ）アクリル系樹脂組成物。
［１１］ リン酸エステル系難燃剤（Ｃ１）及びリン酸エステル系難燃剤（Ｃ２）の合計の含有量が、（メタ）アクリル系重合体（Ｐ）１００質量部に対して、５質量部以上２０質量部以下である、［１０］に記載の（メタ）アクリル系樹脂組成物。
［１２］ 前記（メタ）アクリル系重合体（Ｐ）が、メタクリル酸メチルの単独重合体、及び前記（メタ）アクリル系重合体（Ｐ）の総質量に対して、メタクリル酸メチル由来の繰り返し単位を８５．０質量%以上１００質量％未満含む共重合体からなる群から選択される少なくとも１種である、［１０］又は［１１］に記載の（メタ）アクリル系樹脂組成物。
［１３］ 前記（メタ）アクリル系重合体（Ｐ）が、さらに、前記（メタ）アクリル系重合体（Ｐ）の総質量に対して、ビニル基を２個以上有する単量体（Ｂ）由来の繰り返し単位を０．０５質量％以上０．４０質量％以下含む、［１２］に記載の（メタ）アクリル系樹脂組成物。
［１４］ 前記（メタ）アクリル系重合体（Ｐ）が、前記（メタ）アクリル系重合体（Ｐ）の総質量に対して、メタクリル酸メチル由来の繰り返し単位を９０．０質量%以上９８．０質量％以下、芳香族炭化水素基又は炭素数３～２０の脂環式炭化水素基を側鎖に有する（メタ）アクリル酸エステル（Ｍ）由来の繰り返し単位を２．０質量％以上１０．０質量％以下含む共重合体を含む、［１０］又は［１１］に記載の（メタ）アクリル系樹脂組成物。
［１５］ 前記（メタ）アクリル系重合体（Ｐ）が、さらに、前記（メタ）アクリル系重合体（Ｐ）の総質量に対して、ビニル基を２個以上有する単量体（Ｂ）由来の繰り返し単位を０．０５質量％以上０．４０質量％以下含む、［１４］に記載の（メタ）アクリル系樹脂組成物。
［１６］ ［１０］～［１５］のいずれか一項に記載の（メタ）アクリル系樹脂組成物を成形してなる樹脂成形体。 The present invention has the following aspects.
[1] A phosphate ester flame retardant (C1) containing a compound represented by the following general formula (I).

[In formula (I), R ¹ , R ² and R ³ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a chloroalkyl group having 1 to 4 carbon atoms. Y represents -(CH ₂ ) _x - or -CH ₂ CH ₂ -(OCH ₂ CH ₂ ) _z OCH ₂ CH ₂ -, x is an integer from 3 to 6, and z is an integer from 0 to 3. , n is an integer from 0 to 8.
When measured by gel permeation chromatography (GPC), the average degree of polymerization N calculated from the content of each compound of n = 0 to 8 in the general formula (I) is in the range of 2.1 to 3.3. It is in. ]
[2] The phosphate ester flame retardant (C1) according to [1], wherein the compound represented by the general formula (I) has an average degree of polymerization N of 2.3 or more.
[3] The phosphate ester flame retardant (C1) according to [1] or [2], wherein the compound represented by the general formula (I) has an average degree of polymerization N of 3.1 or less.
[4] The phosphate ester flame retardant according to any one of [1] to [3], wherein the compound represented by the general formula (I) has a viscosity of 1500 to 4500 mPa·s at 25°C. (C1).
[5] In the general formula (I), R ¹ , R ² and R ³ are each independently a hydrogen atom, methyl, ethyl, chloromethyl or chloroethyl group, and Y is a 1,2-propylene group, 1, The phosphoric acid according to any one of [1] to [4], which is a 3-propylene group, -CH ₂ CH ₂ OCH ₂ CH ₂ - or -CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ - Ester flame retardant (C1).
[6] The phosphate ester flame retardant (C1) according to any one of [1] to [5], which is a flame retardant for (meth)acrylic resin compositions.
[7] Contains a compound represented by the following general formula (I),
A phosphate ester flame retardant (C2) having a viscosity of 1500 to 3700 mPa·s at 25°C.

[In formula (I), R ¹ , R ² and R ³ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a chloroalkyl group having 1 to 4 carbon atoms. Y represents -(CH ₂ ) _x - or -CH ₂ CH ₂ -(OCH ₂ CH ₂ ) _z OCH ₂ CH ₂ -, x is an integer from 3 to 6, and z is an integer from 0 to 3. , n is an integer from 0 to 8. ]
[8] In the general formula (I), R ¹ , R ² and R ³ are each independently a hydrogen atom, methyl, ethyl, chloromethyl or chloroethyl group, and Y is a 1,2-propylene group, 1, The phosphate ester flame retardant (C2) according to [7], which is a 3-propylene group, -CH ₂ CH ₂ OCH ₂ CH ₂ - or -CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ -.
[9] The phosphate ester flame retardant (C2) according to [7] or [8], which is a flame retardant for (meth)acrylic resin compositions.
[10] (Meth)acrylic polymer (P), phosphate ester flame retardants (C1) of [1] to [6] and phosphate ester flame retardants (C2) of [7] to [9] A (meth)acrylic resin composition containing at least one selected from the group consisting of:
[11] The total content of the phosphate ester flame retardant (C1) and the phosphate ester flame retardant (C2) is 5 parts by mass or more based on 100 parts by mass of the (meth)acrylic polymer (P). The (meth)acrylic resin composition according to [10], which contains 20 parts by mass or less.
[12] The (meth)acrylic polymer (P) is a homopolymer of methyl methacrylate, and the repeating unit derived from methyl methacrylate is based on the total mass of the (meth)acrylic polymer (P). The (meth)acrylic resin composition according to [10] or [11], which is at least one copolymer selected from the group consisting of copolymers containing 85.0% by mass or more and less than 100% by mass.
[13] The (meth)acrylic polymer (P) is further derived from a monomer (B) having two or more vinyl groups relative to the total mass of the (meth)acrylic polymer (P). The (meth)acrylic resin composition according to [12], which contains 0.05% by mass or more and 0.40% by mass or less of repeating units.
[14] The (meth)acrylic polymer (P) contains 90.0% by mass or more of repeating units derived from methyl methacrylate based on the total mass of the (meth)acrylic polymer (P). 0% by mass or less, 2.0% by mass or more of repeating units derived from (meth)acrylic acid ester (M) having an aromatic hydrocarbon group or an alicyclic hydrocarbon group having 3 to 20 carbon atoms in the side chain; 10. The (meth)acrylic resin composition according to [10] or [11], which contains a copolymer containing 0% by mass or less.
[15] The (meth)acrylic polymer (P) is further derived from a monomer (B) having two or more vinyl groups relative to the total mass of the (meth)acrylic polymer (P). The (meth)acrylic resin composition according to [14], which contains 0.05% by mass or more and 0.40% by mass or less of repeating units.
[16] A resin molded article obtained by molding the (meth)acrylic resin composition according to any one of [10] to [15].

The present invention provides a phosphate ester flame retardant capable of imparting excellent flame retardance, heat resistance, and mechanical strength to a resin molded article, a (meth)acrylic resin composition containing the flame retardant, and the aforementioned flame retardant. A resin molded article formed by molding a (meth)acrylic resin composition can be provided. Such resin molded bodies are suitable for applications that require high flame retardancy, heat resistance, and mechanical strength, such as outdoor signboards such as gas station canopy signs and electronic equipment parts.

The present invention will be explained in detail below. In the present invention, "(meth)acrylate" and "(meth)acrylic acid" refer to at least one kind selected from "acrylate" and "methacrylate" and at least one kind chosen from "acrylic acid" and "methacrylic acid," respectively. means.

Moreover, "monomer" means an unpolymerized compound, and "repeat unit" means a unit derived from the monomer formed by polymerizing the monomer. The repeating unit may be a unit directly formed by a polymerization reaction, or a portion of the unit may be converted into a different structure by processing the polymer.
In the present invention, "mass %" indicates the content ratio of a predetermined component contained in 100 mass % of the total amount.
Unless otherwise specified, a numerical range expressed using "~" in this specification means a range that includes the numerical values written before and after "~" as the lower limit and upper limit, and "A to B" means greater than or equal to A and less than or equal to B.

<<Phosphate ester flame retardant (C)>>
The phosphate ester flame retardant (C) of the present invention is at least one selected from the group consisting of the following phosphate ester flame retardants (C1) and phosphate ester flame retardants (C2).

In the first aspect of the present invention, the phosphate flame retardant (C1) contains a compound represented by the following general formula (I).

[In formula (I), R ¹ , R ² and R ³ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a chloroalkyl group having 1 to 4 carbon atoms. Y represents -(CH ₂ ) _x - or -CH ₂ CH ₂ -(OCH ₂ CH ₂ ) _z OCH ₂ CH ₂ -, x is an integer from 3 to 6, and z is an integer from 0 to 3. , n is an integer from 0 to 8. ]
When measured by gel permeation chromatography (GPC), the average degree of polymerization N calculated from the content of each compound of n = 0 to 8 in the general formula (I) is in the range of 2.1 to 3.3. It is a compound found in

In the second embodiment of the present invention, the phosphate ester flame retardant (C2) contains a compound represented by the following general formula (I) and has a viscosity of 1500 to 3700 mPa·s at 25°C.

[In formula (I), R ¹ , R ² and R ³ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a chloroalkyl group having 1 to 4 carbon atoms. Y represents -(CH ₂ ) _x - or -CH ₂ CH ₂ -(OCH ₂ CH ₂ ) _z OCH ₂ CH ₂ -, x is an integer from 3 to 6, and z is an integer from 0 to 3. Yes, and n is an integer from 0 to 8. ]

Substituents R ¹ , R ² and R ³ in general formula (I) are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a monochloroalkyl group.
The alkyl group having 1 to 4 carbon atoms may be linear or branched, such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, and tert-butyl group. Examples include groups. Among these, methyl group and ethyl group are preferred, and methyl group is more preferred, since the phosphorus content in compound (I) increases.

The monochloroalkyl group having 1 to 4 carbon atoms may be either linear or branched, and includes, for example, a chloromethyl group, a chloroethyl group, a chloropropyl group, and a chlorobutyl group. Among these, chloromethyl group or chloroethyl group is preferred, and chloromethyl group is more preferred, since the phosphorus content in compound (I) increases.
The substituents R ¹ , R ² , and R ³ are preferably a hydrogen atom, a methyl group, an ethyl group, a chloromethyl group, and a chloroethyl group, more preferably a hydrogen atom, a methyl group, and a chloromethyl group; A methyl group is particularly preferred. The substituents R ¹ , R ² and R ³ may be the same or different, and are particularly preferably the same.

The substituent Y in general formula (I) is represented by an alkylene group having 3 to 6 carbon atoms or -CH ₂ CH ₂ (OCH ₂ CH ₂ ) _z OCH ₂ CH ₂ - (z is an integer of 0 to 3) It is the basis.
The alkylene group having 3 to 6 carbon atoms may be either linear or branched, such as 1,2-propylene group, 1,3-propylene group, 1,2-butylene group, 1,3 -butylene group, 1,4-butylene group, 2,3-butylene group, 1,6-hexylene group, 2,4-hexylene group, and 2,5-hexylene group. Among these, 1,2-propylene and 1,3-propylene groups are preferable because they increase the phosphorus content in compound (I).

The group represented by -CH ₂ CH ₂ (OCH ₂ CH ₂ ) _z OCH ₂ CH ₂ - (z is an integer from 0 to 3) is a residue of oxyalkylene glycol, and specifically, -CH ₂ CH ₂ OCH ₂ CH ₂ -, -CH ₂ CH ₂ OCH ₂ CH _{2 OCH 2} CH ₂ -, -CH ₂ CH ₂ (OCH ₂ CH ₂ ) ₂ OCH ₂ CH ₂ -, and -CH ₂ CH ₂ (OCH ₂ CH ₂ ) ₃ OCH ₂ CH ₂ - is mentioned. Among these, -CH ₂ CH ₂ OCH ₂ CH ₂ -, -CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ - are preferred, and -CH ₂ CH ₂ OCH ₂ CH ₂ - is more preferred.
As the substituent Y, 1,2-propylene group, 1,3-propylene group, and -CH ₂ CH ₂ OCH ₂ CH ₂ - are particularly preferred.

The phosphate ester flame retardant (C) has the general formula (I), in which R ¹ , R ² , and R ³ are each independently a hydrogen atom, a methyl group, an ethyl group, a chloromethyl group, or a chloroethyl group, Compounds in which Y is a 1,2-propylene group, a 1,3-propylene group, -CH ₂ CH ₂ OCH ₂ CH ₂ - or -CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ - are preferred. Further, in the general formula (I), a compound in which R ¹ , R ² and R ³ are each independently a hydrogen atom, methyl or chloromethyl group, and Y is -CH ₂ CH ₂ OCH ₂ CH ₂ - More preferred. Furthermore, compounds in which R ¹ , R ² and R ³ are each a methyl group and Y is -CH ₂ CH ₂ -OCH ₂ CH ₂ - are particularly preferred.

In the phosphoric acid ester flame retardant (C), in the general formula (I), n is preferably an integer of 0 to 8, more preferably n is an integer of 1 to 6, and n is 2 to 6. More preferably, it is an integer of 5.

The first aspect of the present invention is characterized in that the average degree of polymerization N of the phosphate ester flame retardant (C1) is in the range of 2.1 to 3.3.

Until now, conventional (meth)acrylic resin compositions containing phosphate ester flame retardants have improved the flame retardancy of resin molded products, but have lowered heat resistance such as deflection temperature under load and glass transition temperature. There was a tendency. The present inventors investigated the reason and found that conventional phosphate ester flame retardants have the effect of coordinating between molecules of (meth)acrylic polymer (P) and weakening the intermolecular force. It has been found that the deflection temperature under load and the glass transition temperature originally possessed by the (meth)acrylic polymer (P) are lowered, and as a result, the heat resistance of the resulting resin molded article is lowered.

Furthermore, the present inventors conducted studies and found that phosphate ester flame retardants with an average degree of polymerization controlled within a specific numerical range that is higher than the average degree of polymerization of conventional phosphate ester flame retardants. By using the flame retardant (C), the obtained resin molded product has heat resistance equivalent to or better than the heat resistance originally possessed by the (meth)acrylic polymer (P), and , and found that it has excellent flame retardancy. Although the reason is not clear, coordination of the phosphate ester flame retardant (C) between the molecules of the (meth)acrylic polymer (P) is suppressed, so the (meth)acrylic resin composition It is presumed that this is because it is possible to suppress a decrease in the deflection temperature under load and the glass transition temperature of , and the glass transition temperature of the phosphate ester flame retardant (C) itself is increased.

That is, when conventional phosphate ester flame retardants are used, there is a so-called trade-off relationship between the heat resistance and flame retardance of the resulting resin molded product, but in the present invention, the average degree of polymerization is controlled within a specific range. By using a phosphate ester flame retardant (C1) with a viscosity of Both characteristics can be achieved.

The phosphate ester flame retardant (C2) may also have the same average degree of polymerization N as the phosphate ester flame retardant (C1).

The lower limit of the average degree of polymerization N of the phosphate ester flame retardant (C) is preferably 2.1 or more, more preferably 2.3 or more, since the heat resistance and weather resistance of the resin molded product are improved. More preferably 4 or more. In addition, the upper limit of the average degree of polymerization N is that if the average degree of polymerization of the phosphate ester flame retardant is too high, the phosphate ester flame retardant will be dispersed in the (meth)acrylic resin composition in the form of aggregated particles. 3.3 or less is preferable, 3.1 or less is more preferable, and 3.0 or less is still more preferable. The above upper limit and lower limit can be arbitrarily combined. For example, the average degree of polymerization N of the phosphoric acid ester flame retardant (C) of the present invention is preferably 2.1 or more and 3.3 or less, more preferably 2.3 or more and 3.1 or less, and 2.4 or more and 3.1 or less. It is more preferably 0 or less. The average degree of polymerization N of the phosphate ester flame retardant (C) can be arbitrarily controlled by adjusting the ratio of raw materials and reaction temperature when synthesizing the phosphate ester flame retardant (C).

Here, a method for calculating the average degree of polymerization N of the phosphate ester flame retardant (C) in this specification will be explained. The average degree of polymerization N can be determined by the following formula using the GPC area fraction (A _n ) of each component where n=0 to 8 in GPC measurement.
N=Σ(n・A _n )/Σ(A _n )
Note that GPC is measured according to the method described below.

The lower limit of the viscosity of the phosphate ester flame retardant (C) is not particularly limited, but from the viewpoint of increasing the heat resistance of the resin molded product, it is preferably 1500 mPa·s or more at 25°C, and more preferably 2000 mPa·s or more. Further, the upper limit of the viscosity is not particularly limited, but from the viewpoint of improving the flame retardance and transparency of the resin molded product, it is preferably 4500 mPa·s or less, more preferably 3700 mPa·s or less, and particularly preferably 3000 mPa·s or less. The above upper limit and lower limit can be arbitrarily combined. For example, the viscosity of the phosphoric acid ester flame retardant (C) of the present invention at 25° C. is preferably 1,500 mPa·s or more and 4,500 mPa·s or less, more preferably 1,500 mPa·s or more and 3,700 mPa·s or less, and 2,000 mPa·s or more and 3,000 mPa·s or less. s or less is more preferable. The viscosity of the phosphate ester flame retardant (C) can be arbitrarily controlled by adjusting the ratio of raw materials and reaction temperature when synthesizing the phosphate ester flame retardant (C).
In this specification, the viscosity of the phosphate ester flame retardant (C) is measured according to the method described below.

<<Synthesis method of phosphate ester flame retardant (C)>>
The phosphoric acid ester flame retardant (C) in the present invention can be obtained, for example, by the following two-stage reaction production method.

(1) First reaction step Phosphorus oxychloride and alkylene glycol or oxyalkylene glycol are reacted to obtain a corresponding chlorophosphate ester as shown in the following general formula (II).

(In general formula (II), Y and n have the same meanings as in general formula (I).)

Here, in the first reaction step, phosphorus oxychloride and alkylene glycol or oxyalkylene glycol are continuously supplied to the reaction tank at a molar ratio of 1.30 to 1.70:1 and reacted. The molar ratio is preferably 1.35 to 1.60:1. By reacting phosphorus oxychloride and alkylene glycol or oxyalkylene glycol at a molar ratio within the above range, a chlorophosphate ester represented by general formula (II) can be obtained. Thereby, a compound of general formula (I) having an average degree of polymerization N within a desired range can be obtained.

The reaction temperature is 0 to 50°C, preferably 15 to 20°C, and the generated heat is removed by passing a coolant through a jacket or coil attached to the reaction vessel.

The alkylene glycol used in the reaction includes 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, and 2,3-butylene glycol. Examples include, but are not limited to, glycol, 1,6-hexanediol, 2,4-hexanediol, and 2,5-hexanediol. As the alkylene glycol, 1,2-propylene glycol and 1,3-propylene glycol are preferred.
Oxyalkylene glycols include, but are not limited to, diethylene glycol, triethylene glycol, and tetraethylene glycol. As the oxyalkylene glycol, diethylene glycol and triethylene glycol are preferred, and diethylene glycol is more preferred.
As the alkylene glycol or oxyalkylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, and diethylene glycol are particularly preferred.

(2) Second reaction step The chlorophosphate obtained in the first reaction step is reacted with alkylene oxide or chloroalkylene oxide to obtain the phosphate ester flame retardant (C) described in the general formula (I). .

(In general formula (III), R ¹ , R ² , R ³ , Y and n have the same meanings as in general formula (I), and R represents a substituent R ¹ , R ² or R ³ )

Examples of the alkylene oxide used in the reaction include ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, 1,2-pentylene oxide, and 1,2-hexylene oxide. , but is not limited to this. Among these, ethylene oxide and propylene oxide are preferred, and propylene oxide is more preferred.
Examples of the chloroalkylene oxide include, but are not limited to, epichlorohydrin.

The reaction temperature is 30-100°C, preferably 40-90°C. At temperatures below 30°C, the reaction progresses very slowly and becomes impractical; at temperatures above 100°C, phenomena such as coloring of the reaction liquid and an increase in side reactants occur, making it difficult to obtain high-quality products. become unable to do so.

(3) Washing and dehydration process The reaction mixture is discharged from the reactor, and is converted into a product through a washing and dehydration process as a purification process.
The washing step is generally carried out by a known method, and can be carried out either batchwise or continuously. Specifically, the reaction mixture is washed with a mineral acid solution such as sulfuric acid or hydrochloric acid, followed by alkaline washing and water washing, and then dehydrated under reduced pressure. Alternatively, the reaction mixture is not washed with a mineral acid but washed with an alkali, the produced water-insoluble titanium compound (catalyst component) is removed by filtration or centrifugation, washed with water, and dehydrated under reduced pressure.

The temperature of the washing step is 95°C or lower, preferably 85°C or lower, more preferably 70°C or lower, and even more preferably 55 to 65°C.
The dehydration step is preferably carried out under reduced pressure. The temperature of the dehydration step is 120° C. or lower, preferably 110° C. or lower, more preferably 95 to 105° C., and the pressure is 10 kPa or lower, preferably 1 to 5 kPa.

The phosphate ester flame retardant (C) of the present invention has excellent flame retardancy when added to a resin. Moreover, the heat resistance of the resin can be improved compared to the case where a conventionally known flame retardant is added. The phosphate ester flame retardant (C) of the present invention has excellent flame retardancy when blended into a (meth)acrylic resin composition, and has improved heat resistance compared to when conventionally known flame retardants are added. It is particularly preferred as a flame retardant for (meth)acrylic resin compositions.

≪(Meth)acrylic resin composition≫
The (meth)acrylic resin composition of the present invention is a (meth)acrylic resin composition containing a (meth)acrylic polymer (P) described below and a phosphate ester flame retardant (C) of the present invention. It is a thing.
Examples of the (meth)acrylic polymer (P) include a repeating unit derived from methyl methacrylate and a repeating unit derived from a monomer (B) having two or more vinyl groups described below. can.

The lower limit of the content of the phosphate ester flame retardant (C) contained in the (meth)acrylic resin composition of the present invention is the resin molded article (hereinafter referred to as Since the flame retardance of the "obtained resin molded product" or "resin molded product" will be good, the amount of 5 parts by mass or more per 100 parts by mass of the (meth)acrylic polymer (P) is It is preferably at least 6 parts by mass, more preferably at least 7 parts by mass. On the other hand, the upper limit of the content of the phosphate ester flame retardant (C) is 20 parts by mass based on 100 parts by mass of the (meth)acrylic polymer, since the resulting resin molded product has good heat resistance. The following is preferable, 19 parts by mass or less is more preferable, and even more preferably 18 parts by weight or less. The above upper limit and lower limit can be arbitrarily combined. For example, the content of the phosphate ester flame retardant (C) contained in the (meth)acrylic resin composition of the present invention is 5 parts or more and 20 parts by mass or more based on 100 parts by mass of the (meth)acrylic resin composition. It is preferably at most 6 parts by mass and at most 19 parts by mass, and even more preferably at least 7 parts by mass and at most 18 parts by mass.

The lower limit of the content of the (meth)acrylic polymer (P) contained in the (meth)acrylic resin composition of the present invention is set so that the heat resistance and mechanical strength of the resulting resin molded product are good. It is preferably 80% by mass or more, more preferably 81% by mass or more, and even more preferably 82% by mass or more, based on 100% by mass of the (meth)acrylic resin composition. On the other hand, the upper limit of the content of the (meth)acrylic polymer (P) is set based on 100% by mass of the (meth)acrylic resin composition from the viewpoint of maintaining good flame retardancy of the resulting resin molded product. , is preferably 95% by mass or less, more preferably 94% by mass or less, even more preferably 93% by mass or less. The above upper limit and lower limit can be arbitrarily combined. For example, the content of the (meth)acrylic polymer (P) contained in the (meth)acrylic resin composition of the present invention is 80% by mass or more based on 100% by mass of the (meth)acrylic resin composition. The content is preferably 95% by mass or less, more preferably 81% by mass or more and 94% by mass or less, and even more preferably 82% by mass or more and 93% by mass or less.

<(meth)acrylic polymer (P)>
The (meth)acrylic resin composition in the present invention contains the following (meth)acrylic polymer (P) as one of the constituent components.
By including the (meth)acrylic polymer (P) as one of the components, it has excellent flame retardancy, heat resistance, and mechanical strength (meth) due to the synergistic effect with other components described below. ) It becomes possible to obtain an acrylic resin molded body.

In the present invention, the (meth)acrylic polymer (P) is a homopolymer of methyl methacrylate or a polymer containing repeating units derived from methyl methacrylate (MMA) (hereinafter referred to as "MMA units"). Coalescing can be used.

Although the lower limit of the content of MMA units contained in the (meth)acrylic polymer (P) is not particularly limited, it is important that the resulting resin molded product have good impact resistance and mechanical strength. , is preferably 85.0% by mass or more, more preferably 90.0% by mass or more, and even more preferably 95.0% by mass or more, based on 100% by mass of the (meth)acrylic polymer (P). On the other hand, the upper limit of the content ratio of MMA units is not particularly limited, but since the flame retardance of the resin molded product is good, the total mass of the (meth)acrylic polymer (P) should be 100% by mass. On the other hand, it is preferably less than 100% by mass, more preferably 98.0% by mass or less, and even more preferably 96.4% by mass or less. Alternatively, it can also be 100% by mass. The above upper limit and lower limit can be arbitrarily combined. For example, the content of MMA units contained in the (meth)acrylic polymer (P) of the present invention is 85.0% by mass with respect to 100% by mass of the total mass of the (meth)acrylic polymer (P). It is preferably at least 90.0 mass% and less than 100 mass%, more preferably at least 90.0 mass% and at most 98.0 mass%, and even more preferably at least 95.0 mass% and at most 96.4 mass%.

However, the lower limit and upper limit of the content of the MMA unit are values that do not take into account the content of repeating units derived from monomer (B), which will be described later, and are substantially less than the lower limit and the upper limit. It is preferable to set the lower limit and upper limit of the MMA unit to values obtained by subtracting the content ratio of repeating units derived from the monomer (B) actually contained. That is, the practical lower limit of the content of the MMA unit is preferably 84.95% by mass or more, and 89.95% by mass or more based on 100% by mass of the (meth)acrylic polymer (P). is more preferable, and even more preferably 94.95% by mass or more. On the other hand, the practical upper limit is preferably 99.95% by mass or less, more preferably 97.95% by mass or less, and even more preferably 96.35% by mass or less. The above upper limit and lower limit can be arbitrarily combined. For example, the content of MMA units contained in the (meth)acrylic polymer (P) of the present invention is 84.95% by mass with respect to 100% by mass of the total mass of the (meth)acrylic polymer (P). It is preferably 99.95% by mass or less, more preferably 89.95% by mass or more and 97.95% by mass, even more preferably 94.95% by mass or more and 96.35% by mass.

Furthermore, the (meth)acrylic polymer (P) contains an aromatic hydrocarbon group or an alicyclic hydrocarbon group having 3 to 20 carbon atoms, based on the total mass of the (meth)acrylic polymer (P). It can contain a repeating unit derived from (meth)acrylic ester (M) having a group in its side chain (hereinafter referred to as "(meth)acrylic ester (M) unit").

The lower limit of the content ratio of (meth)acrylic acid ester (M) units contained in the (meth)acrylic polymer (P) is not particularly limited, but since the flame retardance of the obtained resin molding will be good. , is preferably 2.0% by mass or more, more preferably 3.0% by mass or more, and even more preferably 3.6% by mass or more, based on 100% by mass of the (meth)acrylic polymer (P). On the other hand, the upper limit of the content ratio of (meth)acrylic acid ester (M) units is determined by the total mass of the (meth)acrylic polymer (P) because the impact resistance and mechanical strength of the resin molded product are good. It is preferably 10.0% by weight or less, more preferably 7.0% by weight or less, and even more preferably 5.0% by weight or less, based on 100% by weight. The above upper limit and lower limit can be arbitrarily combined. For example, the content ratio of (meth)acrylic acid ester (M) units contained in the (meth)acrylic polymer (P) of the present invention is 100% by mass of the total mass of the (meth)acrylic polymer (P). On the other hand, the content is preferably 2.0% by mass or more and 10.0% by mass or less, more preferably 3.0% by mass or more and 7.0% by mass or less, and even more preferably 3.6% by mass or more and 5.0% by mass or less. In addition, the specific (meth)acrylic ester (M) will be described later.

Furthermore, the (meth)acrylic polymer (P) has repeating units derived from a monomer (B) having two or more vinyl groups, based on the total mass of the (meth)acrylic polymer (P). (hereinafter referred to as "monomer (B) unit").

Although the lower limit of the content ratio of the monomer (B) units contained in the (meth)acrylic polymer (P) is not particularly limited, since the flame retardance of the obtained resin molded product is good, ( It is preferably 0.05% by mass or more, more preferably 0.10% by mass or more, based on 100% by mass of the total mass of the meth)acrylic polymer (P). On the other hand, the upper limit of the content ratio of the monomer (B) units is not particularly limited, but since the impact resistance and mechanical strength of the resin molding are good, the total content of the (meth)acrylic polymer (P) is It is preferably 0.40% by mass or less, more preferably 0.36% by mass or less, based on 100% by mass. The above upper limit and lower limit can be arbitrarily combined. For example, the content ratio of the monomer (B) units contained in the (meth)acrylic polymer (P) of the present invention is based on 100% by mass of the total mass of the (meth)acrylic polymer (P). , preferably 0.05% by mass or more and 0.40% by mass or less, more preferably 0.10% by mass or more and 0.36% by mass or less. In addition, the specific monomer (B) will be described later.

The above-mentioned (meth)acrylic polymer (P) includes MMA units and (meth)acrylic ester (M) units based on 100% by mass of the (meth)acrylic polymer (P). , polymers containing monomer (B) units in the following content ratios (a) to (d) can be mentioned.
(a) A copolymer containing 85.00% by mass or more and less than 100% by mass of MMA units, or a homopolymer of MMA.
(b) A copolymer containing 99.60% by mass or more and 99.95% by mass or less of MMA units and 0.05% by mass or more and 0.40% by mass or less of monomer (B) units.
(c) A copolymer containing 90.00% by mass or more and 98.00% by mass or less of MMA units and 2.00% by mass or more and 10.00% by mass or less of (meth)acrylate (M) units.
(d) 89.95% by mass or more and 97.95% by mass or less of MMA units, 2.00% by mass or more and 10.00% by mass or less of (meth)acrylic acid ester (M) units, and monomer (B) A copolymer containing 0.05% by mass or more and 0.40% by mass or less of units.
However, the total of each monomer unit does not exceed 100% by mass.

<(meth)acrylic acid ester (M)>
The (meth)acrylic ester (M) is a (meth)acrylic ester having an aromatic hydrocarbon group or an alicyclic hydrocarbon group having 3 to 20 carbon atoms in its side chain.
In the present invention, the (meth)acrylic polymer (P) can contain (meth)acrylic acid ester (M) units as one of the constituent components.
When the (meth)acrylic polymer (P) contains (meth)acrylic acid ester (M) units, the flame retardance of the obtained resin molded product becomes better.

Examples of the (meth)acrylic ester (M) include cyclohexyl (meth)acrylate, bornyl (meth)acrylate, norbornyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, ( Dimethyladamantyl (meth)acrylate, Methylcyclohexyl methacrylate, Norbornylmethyl (meth)acrylate, Menthyl (meth)acrylate, Fenthyl (meth)acrylate, Dicyclopentanyl (meth)acrylate, (meth)acrylic dicyclopentenyl acid, dicyclopentenyloxyethyl (meth)acrylate, cyclodecyl (meth)acrylate, 4-t-butylcyclohexyl (meth)acrylate, trimethylcyclohexyl (meth)acrylate, phenyl (meth)acrylate, Examples include (meth)acrylic acid esters such as benzyl (meth)acrylate and phenoxyethyl (meth)acrylate, and derivatives thereof. These can be used alone or in combination of two or more.

When heat is applied to the (meth)acrylic acid ester (M) unit contained in the (meth)acrylic polymer (P), the side chain is detached and converted into a methacrylic acid structural unit. The methacrylic acid structural unit and the phosphoric acid ester flame retardant (C) act together, and due to their synergistic effect, the amount of carbide produced when the obtained resin molded article is combusted increases. In addition, since the (meth)acrylic polymer (P) further contains a monomer (B) unit having two or more vinyl groups, the formation of carbide when the obtained resin molded product is burned is further suppressed. promoted. The carbide functions as a barrier layer that prevents the transfer of radiant heat to the resin composition, and improves the flame retardancy of the resulting resin molded article. On the other hand, the side chains released from the (meth)acrylic acid ester (M) units consume oxygen, resulting in an oxygen-deficient combustion field, which further improves the flame retardancy of the resin composition.

In the (meth)acrylic resin composition of the present invention, the (meth)acrylic ester (M) includes cyclohexyl (meth)acrylate from the viewpoint of being excellent in improving the flame retardance of the obtained resin molded product. and at least one selected from isobornyl (meth)acrylate.

<Monomer (B)>
The monomer (B) is a monomer having two or more vinyl groups, and the monomer (B) unit is one of the constituent components of the (meth)acrylic polymer (P). When the (meth)acrylic polymer (P) contains the monomer (B) unit, the flame retardance of the obtained resin molded article can be further improved.

As the monomer (B), difunctional (meth)acrylates are preferred, such as ethylene glycol di(meth)acrylate, 1,2-propylene glycol di(meth)acrylate, and 1,3-propylene glycol di(meth)acrylate. Acrylate, 1,2-butylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, 2,3-butylene glycol di(meth)acrylate, Examples include alkanediol di(meth)acrylates such as 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, and tricyclodecane dimethanol di(meth)acrylate. These can be used alone or in combination of two or more.

Among the monomers (B) mentioned above, monomers having 10 to 18 carbon atoms have good handling properties as raw materials, and therefore improve workability when producing a (meth)acrylic resin composition. can.

Furthermore, among the above-mentioned monomers (B), at least one selected from ethylene glycol di(meth)acrylate and neopentyl glycol di(meth)acrylate not only has excellent raw material handling properties, but also provides resin molded products. This is preferable because it can improve the flame retardancy of the material.

<Copolymerizable monomer>
In the present invention, if necessary, a monomer copolymerizable with methyl methacrylate and (meth)acrylic acid ester (M) is added to 100% by mass of the (meth)acrylic polymer (P). It can be contained in the (meth)acrylic polymer (P) in a range of 0 to 12% by mass, preferably 0.8 to 9.0% by mass.

Examples of the copolymerizable monomer include ethyl (meth)acrylate, isopropyl (meth)acrylate, t-butyl (meth)acrylate, I-butyl (meth)acrylate, and (meth)acrylic acid. Unsaturated carboxylic acids such as n-butyl, (meth)acrylic acid, maleic acid, and itaconic acid; acid anhydrides such as maleic anhydride and itaconic anhydride; maleimide derivatives such as N-phenylmaleimide and N-cyclohexylmaleimide; Vinyl esters such as vinyl acetate and vinyl benzoate; vinyl chloride, vinylidene chloride and their derivatives; nitrogen-containing monomers such as methacrylamide and acrylonitrile; epoxy group-containing monomers such as glycidyl acrylate (meth)acrylate; and Examples include aromatic vinyl compounds such as styrene and α-methylstyrene.

The (meth)acrylic resin composition of the present invention can contain general compounding agents, if necessary. Examples of compounding agents include solvents, stabilizers, lubricants, processing aids, plasticizers, impact aids, foaming agents, fillers, antibacterial agents, antifungal agents, foaming agents, mold release agents, antistatic agents, Colorants, matting agents, ultraviolet absorbers, thermoplastic polymers, etc. can be mentioned.

≪Method for producing (meth)acrylic resin composition≫
As a method for obtaining the (meth)acrylic resin composition of the present invention, for example, a polymerizable composition (S2) containing a phosphate ester flame retardant (C) in the monomer composition (S1) shown below is used. ) is obtained by polymerizing.

The content of the phosphate ester flame retardant (C) contained in the polymerizable composition (S2) is as follows: 100 parts by mass of the polymerizable composition (S2) By setting the content to 5 parts by mass or more and 20 parts by mass or less, the flame retardance, heat resistance, and mechanical strength of the obtained resin molded article can be made good.

<Monomer composition (S1)>
The monomer composition (S1) is one embodiment of a raw material for obtaining a (meth)acrylic resin composition, and is a composition containing methyl methacrylate.

Although the content ratio of methyl methacrylate contained in the monomer composition (S1) is not particularly limited, methacrylic acid is By containing 85.0% by mass or more and 100% by mass or less of methyl, the resulting resin molded article can have good transparency and mechanical strength.

Further, the monomer composition (S1) contains the monomer (B) in an amount of 0.05% by mass or more and 0.40% by mass based on 100% by mass of the total mass of the monomer composition (S1). By containing the following, the obtained resin molded article can have good flame retardancy.

Furthermore, by containing the (meth)acrylic acid ester (M), the monomer composition (S1) can improve the flame retardancy of the obtained resin molded article for the reason mentioned above.
The monomer composition (S1) contains the (meth)acrylic acid ester (M) in an amount of 2.0% by mass or more based on 100% by mass of the total mass of the monomer composition (S1). By containing 0% by mass or less, the obtained resin molded article can have good flame retardancy and mechanical strength.

Further, based on 100% by mass of the total mass of the monomer composition (S1), 90.0% by mass to 98.0% by mass of methyl methacrylate, an aromatic hydrocarbon group or a carbon atom having 3 to 20 carbon atoms. By containing 2.0% by mass or more and 10.0% by mass or less of (meth)acrylic acid ester (M) having an alicyclic hydrocarbon group in the side chain, the transparency and mechanical properties of the obtained resin molded article are improved. The target strength can be made good.

The monomer composition (S1) may previously include a polymer (P1) containing MMA units as a main component.
Here, "containing as a main component" means that the polymer (P1) contains the MMA unit in an amount of 85.0% by mass or more, with the total mass of the polymer (P1) being 100% by mass.
The polymer (P1) is a homopolymer of methyl methacrylate, or a copolymer of 85.0% by mass or more and less than 100% by mass of MMA units and methyl methacrylate based on the total mass of the polymer (P1). It is a (co)polymer containing more than 0% by mass and 15.0% by mass or less of repeating units derived from polymerizable monomers.
As the monomer copolymerizable with methyl methacrylate, the same monomer as the above-mentioned "copolymerizable monomer" and "(meth)acrylic ester (M)" can be used.

By including the polymer (P1), the polymerizable composition (S2) becomes a viscous liquid (hereinafter referred to as "syrup"), so the polymerization time can be shortened and productivity can be improved.

Examples of methods for obtaining the syrup described above include the following two methods.
(Method 1) A method of dissolving the polymer (P1) in a monomer mixture containing methyl methacrylate, the methacrylate ester (M), and the monomer (B) (Method 2) Methyl methacrylate (MMA) alone, or a monomer mixture containing 85.0% by mass or more and less than 100% by mass of MMA and more than 0% by mass and 15.0% by mass or less of a monomer copolymerizable with MMA, known radical polymerization initiation. and at least one type selected from the methacrylic acid ester (M), the monomer (B), methyl methacrylate, and a monomer copolymerizable with MMA. A method of adding only a predetermined amount of

A radical polymerization initiator used when polymerizing the monomer mixture to obtain syrup of the polymerizable composition (S2), and a (meth)acrylic resin by polymerizing the polymerizable composition (S2). Examples of the radical polymerization initiator used in obtaining the composition include azo initiators such as 2,2'-azobis(isobutyronitrile) and 2,2'-azobis(2,4-dimethylvaleronitrile). and peroxides such as benzoyl peroxide and lauroyl peroxide. In the present invention, an accelerator such as an amine or a mercaptan may be used together with a radical polymerization initiator, if necessary.

The amount of the radical polymerization initiator added can be appropriately determined depending on the purpose, but is usually 0.01 part by mass or more and 0.50 parts by mass based on 100 parts by mass of monomers in the polymerizable composition (S2). It is as follows.

The polymerization temperature during radical polymerization is usually appropriately set in the range of 10 to 150°C depending on the type of radical polymerization initiator used. Moreover, the polymerizable composition (S2) can be polymerized under multistage temperature conditions as necessary.

Examples of the radical polymerization method include bulk polymerization, suspension polymerization, emulsion polymerization, and dispersion polymerization. Among these, bulk polymerization is preferable from the viewpoint of productivity, and bulk polymerization is preferred. Among these, the cast polymerization (pouring polymerization) method is more preferred.

When obtaining a (meth)acrylic resin composition by a cast polymerization method, the (meth)acrylic resin composition can be obtained, for example, by injecting the polymerizable composition (S2) into a mold and polymerizing it.

≪Resin molded body≫
The resin molded article of the present invention is a molded article formed by molding the (meth)acrylic resin composition of the present invention.
The heat resistance of a molded article made of a resin composition is generally in a so-called trade-off relationship with flame retardancy, in that it tends to decrease as flame retardancy improves. That is, the resin molded article of the present invention is a resin molded article that has the remarkable property of achieving both flame retardancy and heat resistance, which are contradictory properties.

Examples of the shape of the resin molded body include a plate-shaped molded body (resin plate). The thickness of the resin plate is generally 1 mm or more and 30 mm or less. When using the above-mentioned casting method, a resin plate with a desired thickness can be obtained by adjusting the thickness (diameter) of the gasket as appropriate.

≪Method for producing resin molded body≫
The method for producing the (meth)acrylic resin molded article of the present invention is not particularly limited, and for example, two inorganic glass plates or metal plates are sealed around the periphery with a gasket such as a soft resin tube and made to face each other. A cell casting method in which the polymerizable composition (S2) is injected into a mold made of a plate (SUS plate) and heated, or two single-sided mirror-polished stainless steel endless belts and gaskets that proceed in the same direction and at the same speed. A method of obtaining a resin molded body by a continuous casting method in which the polymerizable composition (S2) is continuously injected from upstream using the sealed space as a mold and continuously polymerized by heating is exemplified. The spacing between the voids in the mold is adjusted as appropriate to obtain a resin plate of desired thickness, but is generally 1 to 30 mm.

The present invention will be explained below using examples. In the following, "parts" and "%" refer to "parts by mass" and "% by mass," respectively.

Further, the abbreviations of compounds used in Examples and Comparative Examples are as follows.
MMA: Methyl methacrylate IBXMA: Isobornyl methacrylate CHMA: Cyclohexyl methacrylate EDMA: Ethylene glycol dimethacrylate Flame retardant A: Flame retardant synthesized in Synthesis Example 1 described below (average degree of polymerization N = 2.4, viscosity (25 ° C.) 2100mPa・s)
Flame retardant B: Flame retardant synthesized in Synthesis Example 2 described below (average degree of polymerization N = 2.6, viscosity (25°C) 2300 mPa・s)
Flame retardant C: flame retardant synthesized in Synthesis Example 3 described below (average degree of polymerization N = 2.9, viscosity (25°C) 2800 mPa・s)
Flame retardant D: Flame retardant synthesized in Comparative Synthesis Example 1 described below (average degree of polymerization N = 3.4, viscosity (25°C) 11000 mPa・s)
Flame retardant E: flame retardant synthesized in Comparative Synthesis Example 2 described below (average degree of polymerization N = 1.5, viscosity (25°C) 900 mPa・s)
Flame retardant F: flame retardant synthesized in Comparative Synthesis Example 3 described below (average degree of polymerization N = 1.7, viscosity (25°C) 3800 mPa・s)
Flame retardant G: trimethyl phosphate (trade name: TMP, manufactured by Daihachi Kagaku Kogyo Co., Ltd., viscosity (25°C) 2 mPa・s)

<Evaluation method>
Evaluations in Examples and Comparative Examples were conducted by the following method.

(1) Degree of polymerization The average degree of polymerization N was determined by the following formula using the GPC area fraction (A _n ) of each component with n=0 to 8 in GPC measurement.
N=Σ(n・A _n )/Σ(A _n )
The content of each compound (component) with n=0 to 8 in the organic phosphorus compound (I) measured by GPC was analyzed (measured) as follows, for example.
Specifically, 10 ml of tetrahydrofuran (THF) was added to 0.05 g of the sample to prepare a sample solution, which was analyzed using the following equipment and analysis conditions, and the area % of the RI detector was taken as the content (composition) of each compound. . The content of each compound (component) with n=0 to 8 was taken as the GPC area fraction (A _n ) of each compound, and the average degree of polymerization N was determined from the above formula.
(device)
GPC analyzer (manufactured by Tosoh Corporation, model: HLC-8220 or equivalent)
Data analysis device (manufactured by Tosoh Corporation, model: SC-8010 or equivalent)
(column)
Guard column (manufactured by Tosoh Corporation, model: TSKguardcolumnSuperHZ-L 4.6mmI.D. x 2.0cm) 1 sample column (manufactured by Tosoh Corporation, model: TSKGEL SuperHZ1000
6.0mmI. D. ×15cm) 3 pieces (analysis conditions)
INLET temperature 40℃
Column temperature 40℃
RI temperature 40℃
Solvent flow rate 0.35ml/min Detector RI (Refract Index)
Sample solution injection volume 10 μl (loop tube)
(Data processing conditions)
START TIME (minutes) 8.00
STOP TIME (minutes) 18.00

(2) Viscosity For viscosity measurement, an Ubbelohde viscometer (manufactured by Sogo Rikagaku Glass Seisakusho Co., Ltd., standard: 3C) was used, and the kinematic viscosity and viscosity at 25° C. were determined using the formulas shown below.
ν (kinematic viscosity) = C×t
Viscosity (mPa・s)=ν×ρ
At this time, C is the Ubbelohde viscometer constant, t is the number of seconds of flow (sec.), and ρ is the density (kg/m ³ ) at 25°C.

(3) Flame retardancy (JIS)
As an indicator of the flame retardancy of the (meth)acrylic resin composition and resin molding of the present invention, test pieces of resin moldings obtained in Examples and Comparative Examples (length 127 mm x width 12.7 mm x thickness 3 mm), the time required for the test piece to self-extinguish (self-extinguishing time) was measured in accordance with JIS K 6911-1995 flame resistance test method A. Furthermore, flame retardancy (JIS) was determined using the following criteria.
AA: The self-extinguishing time of the test piece is less than 1 minute.
A: Self-extinguishing time of the test piece is 1 minute or more and less than 3 minutes.
B: The self-extinguishing time of the test piece is 3 minutes or more or it does not self-extinguish.

(4) Flame retardant (UL94)
As an indicator of the flame retardancy of the (meth)acrylic resin composition and resin molding of the present invention, test pieces of resin moldings obtained in Examples and Comparative Examples (length 125 mm x width 13 mm x thickness 3 mm) The flame retardancy was determined using the criteria shown in Table 1 in accordance with the vertical burning test method specified in UL94.

(5) Heat resistance (HDT)
As an index of the heat resistance of the (meth)acrylic resin composition and resin molding of the present invention, test pieces of resin moldings obtained in Examples and Comparative Examples (length 127 mm x width 12.7 mm x thickness 3 mm) were used. ), the deflection temperature under load (hereinafter referred to as "HDT") (°C) was measured in accordance with JIS K 7191.

Furthermore, the overall performance of flame retardancy (JIS) self-extinguishing time and heat resistance was determined using the criteria shown in Table 2.

(6) Bending stress As an index of the mechanical strength of the (meth)acrylic resin composition and resin molding of the present invention, test pieces of resin moldings obtained in Examples and Comparative Examples (length 60 mm x width 25 mm) x thickness 3 mm), the bending stress (MPa) at a distance between fulcrums of 48 mm was measured in accordance with JIS K 7171. Furthermore, mechanical strength was determined using the following criteria.
AA: Bending stress is 100 MPa or more A: Bending stress is 93 MPa or more and less than 100 MPa B: Bending stress is less than 93 MPa

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto.

[Synthesis example 1]
1609.7 g (10.5 mol) of phosphorus oxychloride was charged into a four-necked flask equipped with a Dimroth, and after cooling to below 18°C, 742.7 g (7.0 mol) of diethylene glycol was added until the temperature inside the flask was 18°C. I added this to prevent it from rising above that level. After the addition, hydrochloric acid generated by the reaction was collected into water to obtain 1846.5 g of chlorophosphoric acid ester. Furthermore, 835.4 g of toluene and 10.5 g (0.055 mol) of titanium tetrachloride were charged into another four-necked flask, and 1750.0 g of the chlorophosphate ester obtained before and 1024.1 g (17.6 mol) of propylene oxide were charged. ) was added and reacted at a temperature of 60°C or lower. The obtained organic layer had an acid value of 2.05 KOHmg/g, was neutralized with 10 times the amount of soda ash and water, and after washing with hot water, the solvent was removed and water was removed using a flame retardant A (average degree of polymerization N=2. 4, viscosity=2100 mPa·s) was obtained.

[Synthesis example 2]
2360.8 g (15.4 mol) of phosphorus oxychloride was placed in a four-necked flask equipped with a Dimroth, and after cooling to below 18°C, 1167.1 g (11.0 mol) of diethylene glycol was added until the temperature inside the flask was 18°C. I added this to prevent it from rising above that level. After the addition, hydrochloric acid generated by the reaction was collected into water to obtain 2720.1 g of chlorophosphoric acid ester. Furthermore, 400.0 g of the previous chlorophosphate ester and 1.2 g (0.0063 mol) of titanium tetrachloride were placed in another four-necked flask, and 227.5 g (3.9 mol) of propylene oxide was added at a temperature of 60°C or lower. The reaction was terminated by raising the temperature to 75°C. The obtained organic layer had an acid value of 1.40 KOHmg/g, and was neutralized with 10 times the amount of soda ash and water, washed with hot water, and then dehydrated to obtain flame retardant B (average degree of polymerization N = 2.6, A viscosity of 2300 mPa·s was obtained.

[Synthesis example 3]
After charging 1073.1 g (7.0 mol) of phosphorus oxychloride into a four-necked flask equipped with a Dimroth and cooling it to below 18°C, 530.4 g (5.0 mol) of diethylene glycol was added until the temperature inside the flask reached 18°C. I added this to prevent it from rising above that level. After the addition, hydrochloric acid generated by the reaction was collected into water to obtain 1251.9 g of chlorophosphoric acid ester. Furthermore, 1247.3 g of the previous chlorophosphoric acid ester and 3.7 g (0.020 mol) of titanium tetrachloride were placed in another four-necked flask, and 686.5 g (11.8 mol) of propylene oxide was added at a temperature of 40°C or lower. The reaction was terminated by raising the temperature to 80°C. The obtained organic layer had an acid value of 2.58 KOHmg/g, and was neutralized with 10 times the amount of soda ash and water, washed with hot water, and then dehydrated to obtain flame retardant C (average degree of polymerization N = 2.9, A viscosity of 2800 mPa·s was obtained.

[Comparative synthesis example 1]
After charging 690.0 g (4.5 mol) of phosphorus oxychloride into a four-necked flask equipped with a Dimroth and cooling it to below 18°C, 382.0 g (3.6 mol) of diethylene glycol was added until the temperature inside the flask reached 20°C. I added this to prevent it from rising above that level. After the addition, hydrochloric acid generated by the reaction was collected in water to obtain 795.3 g of chlorophosphoric acid ester. Furthermore, 795.3 g of the previous chlorophosphate ester and 3.0 g (0.016 mol) of titanium tetrachloride were placed in another four-necked flask, and 385.5 g (6.6 mol) of propylene oxide was added at a temperature of 50°C or lower. The reaction was terminated by raising the temperature to 80°C. The obtained organic layer had an acid value of 2.76 KOHmg/g, and was neutralized with 10 times the amount of soda ash and water, washed with hot water, and then dehydrated to obtain flame retardant D (average degree of polymerization N = 3.4, A viscosity of 11,000 mPa·s was obtained.

[Comparative synthesis example 2]
Put 282.4 g (1.8 mol) of phosphorus oxychloride into a four-necked flask equipped with a Dimroth, cool it to below 18°C, then add 106 g (1.0 mol) of diethylene glycol until the temperature inside the flask reaches 18°C or above. I added it so it doesn't go up. After the addition, hydrochloric acid generated by the reaction was collected into water to obtain 307.1 g of chlorophosphoric acid ester. Furthermore, 307.1 g of the previous chlorophosphate ester and 2.1 g (0.011 mol) of titanium tetrachloride were placed in another four-necked flask, and 197.2 g (3.4 mol) of propylene oxide was added at a temperature of 40°C or lower. The reaction was terminated by raising the temperature to 80°C. The obtained organic layer had an acid value of 0.80 KOHmg/g, and was neutralized with 10 times the amount of soda ash and water, washed with hot water, and dehydrated to obtain flame retardant E (average degree of polymerization N = 1.5, A viscosity of 900 mPa·s was obtained.

[Comparative synthesis example 3]
(Reaction process)
A 1000 mL flask equipped with a stirring bar, thermometer, blow tube, and condenser was charged with 275 g (2.0 mol) of phosphorus trichloride, 0.55 g of triethylamine, and 0.65 g of ethylene chlorohydrin. Next, 278 g (5 mol) of propylene oxide was blown in gaseous form from a cylinder through a flowmeter and a blowing pipe at 40 to 50°C. The reaction time was 4 hours. Thereafter, it was aged at 50 to 60°C for 1 hour. The active chlorine concentration of the reaction mixture was 6.9% (theoretical value 7.1%).
56 g (1.1 mol) of acetaldehyde was added to this reaction mixture from a dropping funnel at 30 to 40° C. over 30 minutes. Thereafter, the reaction temperature was gradually raised and the reaction was carried out at 80 to 90°C for 4 hours. The acid value of the reaction mixture was 1.5.
Thereafter, 6 g of a 30% aqueous sodium hydroxide solution was added to the reaction mixture at 5 to 10° C. via a dropping funnel over 20 minutes. The pH of the reaction mixture was 10.5. Next, 90 g (1.0 mol) of a 35% aqueous hydrogen peroxide solution was added at 10 to 20° C. over 4 hours. While adding the hydrogen peroxide aqueous solution, the pH of the reaction mixture was adjusted to 9.5 to 10.5 by appropriately adding a 30% sodium hydroxide aqueous solution. The total amount of 30% aqueous sodium hydroxide solution used was 25 g. After the addition of the hydrogen peroxide aqueous solution was completed, the reaction was continued at 30 to 40°C for 2 hours.
(Post-processing process)
10 g of 30% aqueous sodium hydroxide solution was added to the reaction mixture, and the mixture was stirred at 50 to 60° C. for 1 hour. Next, the mixture was placed in a separatory funnel and separated into an aqueous layer and an organic layer. The obtained organic layer was washed twice with 200 mL of warm water at 60 to 70°C, then the pressure was reduced to 1 to 3 kPa, and low boiling components were removed at 90 to 100°C, and the flame retardant F (average degree of polymerization N = 1.7, viscosity = 3800 mPa·s).
Flame retardant F is a known organic phosphorus compound mainly used as a plasticizer, flame retardant, stabilizer, etc. for synthetic resins. For example, it can be obtained by applying the method described in Example 3 of JP-A No. 11-100391 (in the formula (IV) of the same publication, R = methyl group, Z = hydrogen atom, average degree of polymerization N = 1.7, viscosity = 3800 mPa·s).

[Example 1]
(1) Manufacture of syrup 100 parts of MMA was supplied to a reactor (polymerization pot) equipped with a cooling tube, a thermometer, and a stirrer, and while stirring, nitrogen gas was bubbled, and then heating was started. When the internal temperature reached 60°C, 0.1 part of 2,2'-azobis-(2,4-dimethylvaleronitrile), which is a radical polymerization initiator, was added, and the mixture was further heated to an internal temperature of 100°C. , and was held for 13 minutes. Next, the reactor was cooled to room temperature to obtain syrup (A) consisting of 30% by mass of polymer and 70% by mass of monomer.

(2) Cast polymerization 100 parts by mass of the above syrup (A), 0.15 parts by mass of EDMA as the monomer (B), and the flame retardant A8 obtained in Synthesis Example 1 as the phosphate ester flame retardant (C). 7 parts by mass were mixed, and 0.05 parts by mass of t-hexyl peroxypivalate was added as a polymerization initiator to obtain a polymerizable composition (S2). A mold was prepared by installing a soft resin gasket on the peripheral edge between two SUS plates placed opposite each other so that the gap between the two SUS plates was 4.1 mm. After pouring the polymerizable composition (S2) into the mold and completely sealing it with a soft resin gasket, the temperature was raised to 82°C and held for 30 minutes, and then the temperature was raised to 130°C. The mixture was held for 30 minutes to polymerize the polymerizable composition (S2). Thereafter, it was cooled to room temperature, and the SUS plate was removed to obtain a plate-shaped resin molded product with a thickness of 3 mm.

After each test piece was cut out from the obtained resin molded body using a cutting machine, the cut out surface of the test piece was polished using a milling machine. Table 5 shows the evaluation results of the obtained resin moldings.

[Examples 2 to 9]
A resin molded article was obtained in the same manner as in Example 1 except that the composition of the polymerizable composition (S2) was as shown in Table 3. Table 5 shows the evaluation results of the obtained resin moldings.

[Comparative Examples 1 to 3 and 5 to 9]
A resin molded article was obtained in the same manner as in Example 1, except that the flame retardants listed in Table 3 were used in the amounts listed in Table 3 as comparative flame retardants instead of the phosphate ester flame retardant (C). Table 5 shows the evaluation results of the obtained resin moldings.
In Table 5, the average degree of polymerization of the flame retardants of Comparative Examples 5 and 9 is "-" because the phosphate ester flame retardant (G) used is not a polymer.

[Comparative example 4]
A resin molded body was obtained in the same manner as in Example 1, except that flame retardant F was used as a comparative flame retardant instead of the phosphate ester flame retardant (C), and 5 parts of IBXMA was used as the (meth)acrylic ester (M). Ta. Table 5 shows the evaluation results of the obtained resin moldings.

The resin moldings obtained in Examples 1 to 9 contain 100 parts by mass of the (meth)acrylic polymer (P) and 5 parts by mass or more and 20 parts by mass or less of the phosphate flame retardant (C). , all have flame retardancy (JIS) of non-combustible, heat resistance of 90℃ or higher and bending stress of 100MPa or higher, or flame retardancy (UL) of V-0, heat resistance of 70℃ or higher and bending stress of 90MPa or higher. It has excellent flame retardancy, heat resistance, and mechanical strength.

The resin molded article obtained in Comparative Example 1 had insufficient flame retardancy because the comparative flame retardant had a high average degree of polymerization.

The resin molded article obtained in Comparative Example 2 had insufficient heat resistance because the comparative flame retardant had a low average degree of polymerization and low viscosity.

The resin molded bodies obtained in Comparative Examples 3 and 4 had insufficient flame retardancy because the comparative flame retardant had a low average degree of polymerization and low viscosity.

The resin molded articles obtained in Comparative Examples 5 and 8 had low average degree of polymerization and low viscosity because the comparative flame retardant was not a polymer, and therefore had insufficient flame retardancy and heat resistance.

The resin molded article obtained in Comparative Example 6 had insufficient flame retardancy because the comparative flame retardant had a high average degree of polymerization and a high viscosity.

The resin molded bodies obtained in Comparative Examples 7 and 9 had insufficient heat resistance because the comparative flame retardant had a low average degree of polymerization and low viscosity.

By adding the phosphate ester flame retardant (C) of the present invention to a (meth)acrylic resin composition, it can impart flame retardancy while maintaining heat resistance. In addition, the (meth)acrylic resin composition and resin molding of the present invention have excellent transparency, flame retardancy, heat resistance, mechanical strength, and weather resistance, so they can be used as lighting materials, optical materials, signboards, etc. It can be suitably used for displays, decorative members, architectural members, etc.

Claims (14)

A phosphate ester flame retardant (C1) for use in (meth)acrylic resin compositions, containing a plurality of compounds represented by the following general formula (I).

[In formula (I), R ¹ , R ² and R ³ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a chloroalkyl group having 1 to 4 carbon atoms. Y represents -(CH ₂ ) _x - or -CH ₂ CH ₂ -(OCH ₂ CH ₂ ) _z OCH ₂ CH ₂ -, x is an integer from 3 to 6, and z is an integer from 0 to 3. , n is an integer from 0 to 8.
When measured by gel permeation chromatography (GPC), the average degree of polymerization N calculated from the content of a plurality of compounds of n = 0 to 8 in the general formula (I) is 2.1 to 3.3. in range. ] The phosphate ester flame retardant (C1) according to claim 1, wherein the compound represented by the general formula (I) has an average degree of polymerization N of 2.3 or more. The phosphate ester flame retardant (C1) according to claim 1 or 2, wherein the compound represented by the general formula (I) has an average degree of polymerization N of 3.1 or less. The phosphate ester flame retardant (C1) according to any one of claims 1 to 3, wherein the compound represented by the general formula (I) has a viscosity of 1500 to 4500 mPa·s at 25°C. In the general formula (I), R ¹ , R ² and R ³ are each independently a hydrogen atom, methyl, ethyl, chloromethyl or chloroethyl group, and Y is a 1,2-propylene group, 1,3-propylene The phosphate ester flame retardant according to any one of claims 1 to 4, which is a group, -CH ₂ CH ₂ OCH ₂ CH ₂ - or -CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ - C1). Contains a plurality of compounds represented by the following general formula (I),
A phosphate ester flame retardant (C2) having a viscosity of 1500 to 3700 mPa·s at 25° C. and used for (meth)acrylic resin compositions .

[In formula (I), R ¹ , R ² and R ³ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a chloroalkyl group having 1 to 4 carbon atoms. Y represents -(CH ₂ ) _x - or -CH ₂ CH ₂ -(OCH ₂ CH ₂ ) _z OCH ₂ CH ₂ -, x is an integer from 3 to 6, and z is an integer from 0 to 3. , n is an integer from 0 to 8. ] In the general formula (I), R ¹ , R ² and R ³ are each independently a hydrogen atom, methyl, ethyl, chloromethyl or chloroethyl group, and Y is a 1,2-propylene group, 1,3-propylene The phosphate ester flame retardant (C2) according to claim 6 , wherein the group is -CH ₂ CH ₂ OCH ₂ CH ₂ - or -CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ -. Consisting of a (meth)acrylic polymer (P), the phosphate ester flame retardant (C1) according to any one of claims 1 to 5, and the phosphate ester flame retardant (C2) according to claim 6 or 7. A (meth)acrylic resin composition containing at least one member selected from the group consisting of: The total content of the phosphate ester flame retardant (C1) and the phosphate ester flame retardant (C2) is 5 parts by mass or more and 20 parts by mass based on 100 parts by mass of the (meth)acrylic polymer (P). The (meth)acrylic resin composition according to claim 8 , which is as follows. The (meth)acrylic polymer (P) contains 85% of repeating units derived from methyl methacrylate based on the total mass of the methyl methacrylate homopolymer and the (meth)acrylic polymer (P). The (meth)acrylic resin composition according to claim 8 or 9 , which is at least one copolymer selected from the group consisting of copolymers containing 0% by mass or more and less than 100% by mass. The (meth)acrylic polymer (P) further comprises a repeating unit derived from a monomer (B) having two or more vinyl groups relative to the total mass of the (meth)acrylic polymer (P). The (meth)acrylic resin composition according to claim 10 , comprising 0.05% by mass or more and 0.40% by mass or less. The (meth)acrylic polymer (P) contains repeating units derived from methyl methacrylate in an amount of 90.0% by mass or more and 98.0% by mass based on the total mass of the (meth)acrylic polymer (P). Hereinafter, 2.0% by mass or more and 10.0% by mass of repeating units derived from (meth)acrylic acid ester (M) having an aromatic hydrocarbon group or an alicyclic hydrocarbon group having 3 to 20 carbon atoms in the side chain. The (meth)acrylic resin composition according to claim 8 or 9 , comprising a copolymer comprising: The (meth)acrylic polymer (P) further comprises a repeating unit derived from a monomer (B) having two or more vinyl groups relative to the total mass of the (meth)acrylic polymer (P). The (meth)acrylic resin composition according to claim 12 , comprising 0.05% by mass or more and 0.40% by mass or less. A resin molded article obtained by molding the (meth)acrylic resin composition according to any one of claims 8 to 13 .