JP2018154763A - (meth)acrylic resin composition and resin molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a (meth)acrylic resin composition having moderate light diffusivity, high flame retardancy and high heat resistance, and to provide a resin molding comprising the (meth)acrylic resin composition.SOLUTION: The (meth)acrylic resin composition contains a (meth)acrylic polymer (P), a halogen-containing phosphorus-based flame retardant (C), an inorganic pigment (D), and a halogen-free phosphate ester (E). The (meth)acrylic polymer (P) contains: a repeating unit derived from a methacrylate ester (M1) having an aromatic hydrocarbon group or a C3-20 alicyclic hydrocarbon group in a side chain; and a repeating unit derived from an acrylate ester (M2) having an aromatic hydrocarbon group or a C3-20 alicyclic hydrocarbon group in a side chain.SELECTED DRAWING: None

Description

  The present invention relates to a (meth) acrylic resin composition and a resin molded body.

(Meth) acrylic resin based on methyl methacrylate is excellent in transparency and weather resistance, and has a relatively balanced performance in terms of resin properties such as mechanical strength, thermal properties, and moldability. doing. In particular, (meth) acrylic resin having high flame retardancy is used in many applications such as lighting materials, signboards, decorative members, and building members.
Recently, when flame-retardant (meth) acrylic resin is used for signboards and lighting applications installed indoors and outdoors, the shape of light sources such as fluorescent lamps and LEDs is concealed by signboards and lighting covers. In addition, a (meth) acrylic resin having an appropriate light diffusibility is demanded.

As a technique for improving the flame retardancy of a (meth) acrylic resin, for example, Patent Document 1 discloses a flame-retardant (meth) acrylic resin plate containing a halogen-containing phosphate ester as a flame retardant. Discloses a flame-retardant (meth) acrylic resin plate containing a halogen-free organophosphorus compound as a flame retardant.
In addition, as a technology for imparting flame retardancy and light diffusibility to a (meth) acrylic resin plate, Patent Document 3 discloses (meth) acrylic resin, phosphorus flame retardant, barium sulfate and titanium oxide as a light diffusing agent, etc. A (meth) acrylic resin plate containing the inorganic pigment is disclosed.

International Publication No. 2016/063898 JP2015-86250A Japanese Patent Laid-Open No. 5-311026

The methacrylic resin plate disclosed in Patent Document 1 has excellent flame retardancy and heat resistance, and the methacrylic resin plate disclosed in Patent Document 2 has improved flame retardancy. However, simply adding an existing inorganic pigment as a light diffusing agent to these methacrylic resin plates reduces the flame retardancy of the methacrylic resin plates because the light diffusing agent itself reduces the flame retardant properties of the methacrylic resin plates. That was a challenge.
Moreover, in the flame-retardant methacrylic resin plate using the inorganic pigment disclosed in Patent Document 3 as a light diffusing agent, flame retardance suitable for a lighting cover, a signboard or the like is not obtained. That is, it has been difficult to obtain a (meth) acrylic resin excellent in flame retardancy, heat resistance, and light diffusibility by the prior art.

  An object of the present invention is to provide a (meth) acrylic resin composition having moderate light diffusivity, high flame retardancy and heat resistance, and a resin molded body comprising the (meth) acrylic resin composition. .

（式（Ｉ）中、Ｒは炭素数１〜２４のアルキル基、炭素数３〜６のシクロアルキル基、炭素数１〜２４のアリール基、炭素数１〜２４のアルコキシ基、炭素数１〜２４のアルコキシカルボニル基、炭素数１〜２４のアルキルカルボキシル基、又は炭素数１〜２４のアルキレン基、を示し、ｎは１又は２である。）
［５］前記式（Ｉ）中、Ｒが炭素数４〜２４の芳香族アルキル基又は炭素数４〜２４の脂肪族アルキル基である、［４］に記載の（メタ）アクリル樹脂組成物。
［６］前記ハロゲン非含有リン酸エステル（Ｅ）が２−エチルヘキシルアシッドホスフェートである、［４］又は［５］に記載の（メタ）アクリル樹脂組成物。
［７］前記メタクリル酸エステル（Ｍ１）由来の繰り返し単位の割合が、（メタ）アクリル重合体（Ｐ）の総質量に対し、１０質量％以上８０質量％以下であり、
前記アクリル酸エステル（Ｍ２）由来の繰り返し単位の割合が、（メタ）アクリル重合体（Ｐ）の総質量に対し、０．５０質量％以上２０質量％以下であり、
前記単量体（Ｂ）由来の構造単位の割合が、（メタ）アクリル重合体（Ｐ）の総質量に対し、０．０５質量％以上０．４０質量％以下である、［２］に記載の（メタ）アクリル樹脂組成物。
［８］前記ハロゲン含有リン系難燃剤（Ｃ）が、ハロゲン含有リン酸エステル及びハロゲン含有ホスホン酸エステルからなる群から選ばれる少なくとも１種である、［１］〜［７］のいずれか一項に記載の（メタ）アクリル樹脂組成物。
［９］［１］〜［８］のいずれか一項に記載の（メタ）アクリル樹脂組成物からなる樹脂成形体。
［１０］下記条件（１）〜（３）を満足する樹脂成形体。
条件（１）：ＪＩＳ Ｋ６９１１ 難燃性Ａ法試験にて燃焼試験を行った場合に３分以内で自消する難燃性を有する。
条件（２）：ＤＩＮ ５０３６にて測定した拡散率が９０％以上９９％以下である。
条件（３）：ＪＩＳ Ｋ ７１９１に準拠して測定した荷重たわみ温度が７５℃以上である。
［１１］ＪＩＳ Ｋ ７１９１に準拠して測定した荷重たわみ温度が９０℃以上である、［９］又は［１０］に記載の樹脂成形体。
［１２］ＵＬ９４で規定される垂直燃焼試験においてＶ−０の難燃性を有する、［９］〜［１１］のいずれか一項に記載の樹脂成形体。 The present invention has the following aspects.
[1] A (meth) acrylic resin composition containing a (meth) acrylic polymer (P), a halogen-containing phosphorus-based flame retardant (C), an inorganic pigment (D), and a halogen-free phosphate ester (E). And
The (meth) acrylic polymer (P) is a repeating unit derived from a methacrylic acid ester (M1) having an aromatic hydrocarbon group or an alicyclic hydrocarbon group having 3 to 20 carbon atoms in the side chain, and aromatic carbonization. Containing a repeating unit derived from an acrylate ester (M2) having a hydrogen group or an alicyclic hydrocarbon group having 3 to 20 carbon atoms in the side chain, and
Content of the said halogen-containing phosphorus flame retardant (C) is 5.0 mass parts or more and 35 mass parts or less with respect to 100 mass parts of said (meth) acrylic polymers (P),
The content of the inorganic pigment (D) is 0.05 parts by mass or more and 0.35 parts by mass or less with respect to 100 parts by mass of the (meth) acrylic polymer (P),
The content of the halogen-free phosphate ester (E) is 0.005 parts by mass or more and 0.15 parts by mass or less with respect to 100 parts by mass of the (meth) acrylic polymer (P). Resin composition.
[2] The (meth) acrylic resin composition according to [1], wherein the (meth) acrylic polymer (P) contains a structural unit derived from the monomer (B) having two or more vinyl groups.
[3] The (meth) acrylic resin composition according to [1] or [2], wherein the inorganic pigment (D) is titanium oxide.
[4] The (meth) acrylic resin composition according to any one of [1] to [3], wherein the halogen-free phosphate ester (E) is a compound represented by the following formula (I).

(In the formula (I), R is an alkyl group having 1 to 24 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an aryl group having 1 to 24 carbon atoms, an alkoxy group having 1 to 24 carbon atoms, and 1 to 1 carbon atoms. 24 represents an alkoxycarbonyl group, an alkylcarboxyl group having 1 to 24 carbon atoms, or an alkylene group having 1 to 24 carbon atoms, and n is 1 or 2.)
[5] The (meth) acrylic resin composition according to [4], wherein in the formula (I), R is an aromatic alkyl group having 4 to 24 carbon atoms or an aliphatic alkyl group having 4 to 24 carbon atoms.
[6] The (meth) acrylic resin composition according to [4] or [5], wherein the halogen-free phosphate ester (E) is 2-ethylhexyl acid phosphate.
[7] The ratio of the repeating unit derived from the methacrylic acid ester (M1) is 10% by mass or more and 80% by mass or less with respect to the total mass of the (meth) acrylic polymer (P).
The ratio of the repeating unit derived from the acrylate ester (M2) is 0.50% by mass or more and 20% by mass or less with respect to the total mass of the (meth) acrylic polymer (P).
The ratio of the structural unit derived from the monomer (B) is 0.05% by mass or more and 0.40% by mass or less with respect to the total mass of the (meth) acrylic polymer (P). (Meth) acrylic resin composition.
[8] Any one of [1] to [7], wherein the halogen-containing phosphorus flame retardant (C) is at least one selected from the group consisting of a halogen-containing phosphate ester and a halogen-containing phosphonate ester. The (meth) acrylic resin composition as described in 2.
[9] A resin molded body comprising the (meth) acrylic resin composition according to any one of [1] to [8].
[10] A resin molded body that satisfies the following conditions (1) to (3).
Condition (1): Has a flame retardancy that self-extinguishes within 3 minutes when a combustion test is performed in JIS K6911 flame retardancy A method test.
Condition (2): The diffusivity measured by DIN 5036 is 90% or more and 99% or less.
Condition (3): The deflection temperature under load measured in accordance with JIS K 7191 is 75 ° C. or higher.
[11] The resin molded product according to [9] or [10], wherein a deflection temperature under load measured in accordance with JIS K 7191 is 90 ° C or higher.
[12] The resin molded body according to any one of [9] to [11], which has a flame retardancy of V-0 in a vertical combustion test defined by UL94.

  According to the present invention, it is possible to obtain a resin molded article having moderate light diffusibility and high flame retardancy and heat resistance as a signboard / illuminating material, and a (meth) acrylic resin composition for obtaining the resin molded article.

The present invention is described in detail below.
In the present invention, “(meth) acrylate” means at least one selected from the group consisting of “acrylate” and “methacrylate”. “(Meth) acrylic acid” means at least one selected from the group consisting of “acrylic acid” and “methacrylic acid”.

  “Monomer” means an unpolymerized compound, and “repeating unit” means a unit derived from the monomer formed by polymerization of the monomer. The repeating unit may be a unit directly formed by a polymerization reaction, or may be a part of the unit converted into another structure by treating the polymer. “Structural unit” means a unit derived from a monomer used in the production of a (meth) acrylic resin composition. Further, “mass%” indicates the content of a predetermined component contained in the total amount of 100 mass%.

<(Meth) acrylic resin composition>
The resin molded product of the present invention contains a (meth) acrylic polymer (P), a halogen-containing phosphorus-based flame retardant (C), an inorganic pigment (D), and a halogen-free phosphate ester (E) described later (meta). ) A resin molded body made of an acrylic resin composition.

  The content of the halogen-containing phosphorus flame retardant (C) in the (meth) acrylic resin composition is not particularly limited, but is 5.0 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer (P). The amount can be 35 parts by mass or less.

  If the lower limit of the content of the halogen-containing phosphorus-based flame retardant (C) is 5.0 parts by mass or more, the flame retardancy of the resin molded article is improved, and 8.0 parts by mass or more is more preferable. If the upper limit of the content of the halogen-containing phosphorus-based flame retardant (C) is 35 parts by mass or less, the heat resistance of the resin molded article is improved, and 23 parts by mass or less is more preferable.

  By setting the content of the inorganic pigment (D) to 0.05 parts by mass or more and 0.35 parts by mass or less with respect to 100 parts by mass of the (meth) acrylic polymer (P), a resin molded body having an appropriate diffusivity is obtained. It is done. Moreover, if the upper limit of content of an inorganic pigment (D) is 0.35 mass part or less, it is preferable from the ability to maintain the flame retardance of a resin molding, and 0.25 mass part or less is more preferable. If the minimum of content of an inorganic pigment (D) is 0.1 mass part or more, it is preferable from the ability to provide a moderate diffusion rate to a resin molding, and 0.25 mass part or less is more preferable.

  Furthermore, in the resin molded body of the present invention, the halogen-free phosphate ester (E) interacts with the inorganic pigment (D), and has an effect of uniformly dispersing the inorganic pigment (D) in the resin molded body. Since it has, the flame retardance of a resin molding can be improved. If the lower limit of the content of the halogen-free phosphate ester (E) with respect to 100 parts by mass of the (meth) acrylic polymer (P) is 0.005 parts by mass or more, the dispersion of the inorganic pigment (D) in the resin molded body The flame retardance of the resin molding can be improved. Moreover, if the upper limit of content is 0.15 mass part or less, the dispersibility of the inorganic pigment (D) in a resin molding will become favorable.

<(Meth) acrylic polymer (P)>
The (meth) acrylic resin composition in this invention contains the following (meth) acrylic polymer (P) as one of the structural components. By including the (meth) acrylic polymer (P) as one of the constituent components, a resin molded product having an appropriate light diffusibility and high flame retardancy is obtained by a synergistic effect with other constituent components described later. It becomes possible.

In the present invention, the (meth) acrylic polymer (P) is a repeating unit derived from a methacrylic acid ester (M1) having an aromatic hydrocarbon group or an alicyclic hydrocarbon group having 3 to 20 carbon atoms in the side chain; It contains a repeating unit derived from an acrylate ester (M2) having an aromatic hydrocarbon group or an alicyclic hydrocarbon group having 3 to 20 carbon atoms in the side chain.
In the present specification, “side chain” means an ester moiety.
Furthermore, the (meth) acrylic polymer (P) can contain a structural unit derived from the monomer (B) having two or more vinyl groups.
Details of the methacrylic acid ester (M1), the acrylic acid ester (M2) and the monomer (B) will be described later.

Further, the (meth) acrylic polymer (P) is 10% by mass to 80% by mass of the repeating unit derived from the methacrylic acid ester (M1) with respect to the total mass of the (meth) acrylic polymer (P). By containing 0.50% by mass or more and 20% by mass or less of the repeating unit derived from the acrylate ester (M2), the flame retardancy of the resin molded product can be further improved.
Further, the (meth) acrylic polymer (P) is 0.05% by mass or more and 0.40% by mass of the structural unit derived from the monomer (B) with respect to the total mass of the (meth) acrylic polymer (P). By containing at most%, the flame retardancy of the resin molded product can be further improved.

  The lower limit of the content of the repeating unit derived from the methacrylic acid ester (M1) is 10% with respect to the total mass of the (meth) acrylic polymer (P) because the flame retardancy and heat resistance of the resin molded article are improved. The mass% or more is preferable. Moreover, since the weather resistance of a resin molding becomes favorable, the upper limit of content is preferable 80 mass% or less.

  The lower limit of the content of the repeating unit derived from the acrylate ester (M2) is 0 with respect to the total mass of the (meth) acrylic polymer (P) because the flame retardancy and weather resistance of the resin molded article are improved. .50% by mass or more is preferable, 1.0% by mass or more is more preferable, and 2.0% by mass or more is more preferable. The upper limit of the content is preferably 20% by mass or less, more preferably 5.0% by mass or less, and even more preferably 4.0% by mass or less because the heat resistance of the resin molded article becomes favorable.

  The lower limit of the total content of the repeating unit derived from the methacrylic acid ester (M1) and the repeating unit derived from the acrylate ester (M2) is not particularly limited, but the flame retardancy of the resin molded article becomes favorable. 15 mass% or more is preferable with respect to the total mass of a (meth) acrylic polymer (P), and 20 mass% or more is more preferable. The upper limit of the content is preferably 80% by mass or less, more preferably 45% by mass or less, and even more preferably 25% by mass or less because the heat resistance of the resin molded article can be maintained satisfactorily.

    Moreover, the said (meth) acrylic polymer (P) can make the transparency and mechanical strength of a resin molding favorable by including the repeating unit derived from methyl methacrylate. The lower limit of the content of the repeating unit derived from methyl methacrylate in the (meth) acrylic polymer (P) is not particularly limited. However, since the transparency and mechanical strength of the resin molded article are improved, ( 20 mass% or more is preferable with respect to the total mass of a meth) acrylic polymer (P). Moreover, although the upper limit of content is not specifically limited, Since the flame retardance of a resin molding can be maintained favorable, 85 mass% or less is preferable.

Although the minimum of content of the structural unit derived from the said monomer (B) is not specifically limited, Since the flame retardance of a resin molding becomes favorable, with respect to the total mass of a (meth) acrylic polymer (P). 0.05 mass% or more is preferable. Moreover, although the upper limit of content is not specifically limited, 0.40 mass% or less is preferable since the impact resistance and mechanical strength of a resin molding become favorable. A specific monomer (B) will be described later.
Examples of the method for producing the (meth) acrylic polymer (P) include a bulk polymerization method, a solution polymerization method, an emulsion polymerization method, and a suspension polymerization method. Among these, bulk polymerization is preferred from the viewpoint of the production cost of the (meth) acrylic polymer, the environmental load due to the use of a solvent, and the productivity.

<Methacrylic acid ester (M1), acrylic acid ester (M2)>
In the present invention, the (meth) acrylic polymer (P) is an aromatic hydrocarbon or a repeating unit derived from a methacrylic acid ester (M1) having an alicyclic hydrocarbon having 3 to 20 carbon atoms in the side chain, and an aromatic It contains a repeating unit derived from an acrylate ester (M2) having a hydrocarbon group or an alicyclic hydrocarbon group having 3 to 20 carbon atoms in the side chain. (Hereinafter, the methacrylic acid ester (M1) and the acrylic acid ester (M2) are combined and abbreviated as “(meth) acrylic acid ester (M)”, if necessary.)

When heat is applied to the (meth) acrylic acid ester (M), the side chain is detached and converted to a (meth) acrylic acid structural unit. The (meth) acrylic acid structural unit acts on and interacts with the halogen-containing phosphorus-based flame retardant (C), thereby increasing the amount of carbide (char) generated when the resin composition burns. As a result, the flame retardancy of the resin molded body is improved. On the other hand, the side chain desorbed from the (meth) acrylic acid ester (M) consumes oxygen and the combustion field becomes in a state of oxygen deficiency, so that the flame retardancy of the resin composition is further enhanced.
Moreover, the production | generation of a carbide | carbonized_material (char) is further accelerated | stimulated by adding the monomer (B) mentioned later.
In particular, by including the acrylic ester (M2), the unreacted monomer in the (meth) acrylic resin composition after polymerization can be further reduced, and the weather resistance of the resin molded product becomes better. . Furthermore, since the acrylic ester (M2) interacts with the halogen-containing phosphorus-based flame retardant (C) and has the effect of synergistically increasing the flame retardancy improving effect of the halogen-containing phosphorus-based flame retardant (C). The flame retardancy of the resin molded product can be improved.

  Specific examples of the (meth) acrylate ester (M) include cyclohexyl (meth) acrylate, bornyl (meth) acrylate, norbornyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, Dimethyl adamantyl (meth) acrylate, methyl cyclohexyl methacrylate, norbornyl methyl (meth) acrylate, menthyl (meth) acrylate, phenethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, (meth) Dicyclopentenyl acrylate, dicyclopentenyloxyethyl (meth) acrylate, cyclodecyl (meth) acrylate, 4-t-butylcyclohexyl (meth) acrylate, trimethylcyclohexyl (meth) acrylate, benzyl (meth) acrylate , (Meta) a (Meth) acrylic acid esters such as acrylic acid phenoxy ethyl, and derivatives thereof, but are not limited thereto. These can be used alone or in combination of two or more.

  In the (meth) acrylic resin composition of the present invention, the methacrylic acid ester (M1) is at least selected from the group consisting of cyclohexyl methacrylate and isobornyl methacrylate from the viewpoint of excellent effects of improving flame retardancy and heat resistance. One monomer can be used.

  In the (meth) acrylic resin composition of the present invention, the acrylic ester (M2) is a group consisting of cyclohexyl acrylate and isobornyl acrylate, from the viewpoint of improving the flame retardancy and weather resistance of the resin molded product. At least one monomer selected from can be used.

<Monomer (B)>
The monomer (B) is a monomer having two or more vinyl groups and is one of the components of the (meth) acrylic polymer (P). By containing the monomer (B) in the (meth) acrylic resin composition, the flame retardancy of the resin molded product can be further improved.

  Examples of the monomer (B) include ethylene glycol di (meth) acrylate, 1,2-propylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, and 1,6-hexanediol diene. Examples include alkanediol di (meth) acrylates such as (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) described above, the monomer (B) having 10 to 14 carbon atoms has good handleability of raw materials, and therefore, workability when producing a (meth) acrylic resin composition. Will improve.

  Furthermore, if the monomer (B) is at least one monomer selected from the group consisting of ethylene glycol di (meth) acrylate and neopentyl glycol di (meth) acrylate, the raw material handling properties are excellent. In addition, it is preferable from the viewpoint that the flame retardancy of the resin molded product can be made more excellent.

<Copolymerizable monomer>
In the present invention, a monomer that can be copolymerized with methyl methacrylate or (meth) acrylic acid ester (M) in (meth) acrylic polymer (P), if necessary, (meth) acrylic polymer It can copolymerize in 0-10 mass% with respect to the total mass of (P).

  As a monomer copolymerizable with (meth) acrylic acid ester (M), for example, ethyl (meth) acrylate, isopropyl (meth) acrylate, t-butyl (meth) acrylate, (meth) acrylic acid i-butyl, n-butyl (meth) acrylate, (meth) acrylic acid, maleic acid, itaconic acid and other unsaturated carboxylic acids, maleic anhydride, itaconic anhydride and other acid anhydrides, N-phenylmaleimide, N -Maleimide derivatives such as 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, glycidyl acrylate (meth) acrylate, etc. Epoxy group-containing monomers and aromatic vinyl compounds such as styrene and α-methylstyrene And the like.

<Halogen-containing phosphorus flame retardant (C)>
The halogen-containing phosphorus flame retardant (C) is one of the components of the (meth) acrylic resin composition. When the (meth) acrylic resin composition contains the halogen-containing phosphorus-based flame retardant (C), flame retardancy can be imparted to the resin molded body.
Combining the halogen-containing phosphorus-based flame retardant (C) having the effect of improving flame retardancy with the repeating unit derived from the (meth) acrylic acid ester (M) contained in the acrylic polymer (P) provides a flame retardant synergistic effect. It is obtained and the flame retardancy of the resin molding can be improved.

  Examples of the halogen-containing phosphorus flame retardant (C) include a halogen-containing phosphate ester compound (hereinafter abbreviated as “halogen-containing phosphate ester”) and a halogen-containing phosphonate ester compound (hereinafter “halogen-containing phosphonic acid”). Abbreviated as “ester”). Specifically, the following compounds can be exemplified, but are not limited thereto. These compounds can be used alone or in combination of two or more.

  Examples of halogen-containing phosphate esters include tris (chloroethyl) phosphate, tris (chloropropyl) phosphate, tris (dichloropropyl) phosphate, tris (dibromopropyl) phosphate, and bis (2,3-dibromopropyl) -2. , 3-dichloropropyl phosphate, bis (chloropropyl) octyl phosphate, etc., and derivatives thereof, and their condensates; and polyphosphates containing halogen atoms such as halogenated alkylpolyphosphates (halogen-containing) Condensed phosphate ester), and derivatives thereof.

  Specifically, “TMCPP”, “MCPP”, “CRP”, “CR-900”, “DAIGUARD-540”, “CR-504L”, “CR-570”, etc., manufactured by Daihachi Chemical Industry Co., Ltd. Is mentioned.

  Examples of the halogen-containing phosphonic acid ester include compounds obtained by halogenating dimethyl vinyl phosphonate, diethyl vinyl phosphonate, diphenyl vinyl phosphonate, diphenyl vinyl phosphine oxide, and derivatives thereof.

<Halogen-free phosphate (E)>
Halogen-free phosphate ester (E) is one of the constituent components of the resin molding of the present invention. Since the halogen-free phosphate ester (E) interacts with the inorganic pigment (D) described later and has the effect of synergistically increasing the dispersion stability of the inorganic pigment (D), the flame retardancy of the resin molded product Can be improved. Furthermore, the effect is remarkably obtained when the acrylic polymer (P) contains a repeating unit derived from the (meth) acrylic acid ester (M).

  Examples of the halogen-free phosphate ester (E) include compounds represented by the following formula (I).

(In the formula (I), R is an alkyl group having 1 to 24 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an aryl group having 1 to 24 carbon atoms, an alkoxy group having 1 to 24 carbon atoms, and 1 to 1 carbon atoms. 24 represents an alkoxycarbonyl group, an alkylcarboxyl group having 1 to 24 carbon atoms, or an alkylene group having 1 to 24 carbon atoms, and n is 1 or 2.)

As the halogen-free phosphate ester (E), a halogen-free phosphate ester in which R is an aromatic alkyl group or aliphatic alkyl group having 4 to 24 carbon atoms in the formula (I) is an inorganic pigment (D). It is preferable because it is excellent in the effect of increasing the dispersion stability of the resin.
Specific examples of the halogen-free phosphate ester (E) include monoethyl phosphate, mono n-butyl phosphate, methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, 2-ethylhexyl acid phosphate, and the like However, the present invention is not limited to these compounds. These can be used alone or in combination of two or more. Among the compounds described above, 2-ethylhexyl acid phosphate is preferable because it is excellent in the effect of increasing the dispersion stability of the inorganic pigment (D).

  Commercially available products can be used as the halogen-free phosphate ester (E), for example, “JAMP-2”, “JP-502”, “JP-504” and “JP” manufactured by Johoku Chemical Industry Co., Ltd. -508 ".

<Inorganic pigment (D)>
The resin molding of this invention is manufactured using the (meth) acrylic resin composition containing an inorganic pigment (D). By using the inorganic pigment (D) as a light diffusing agent, the resin molded product can exhibit appropriate light diffusibility while maintaining high flame retardancy.
Examples of the inorganic pigment (D) include barium sulfate, calcium carbonate, aluminum hydroxide, aluminum potassium silicate (mica), aluminum silicate (kaolin), titanium oxide, silicon dioxide, potassium fluoride, and magnesium silicate (talc). ), And inorganic compounds such as glass beads, but are not limited thereto. These can be used alone or in combination of two or more. Of these, titanium oxide is preferable from the viewpoint of the flame retardancy of the resin molded product.
Further, as a method for improving the dispersibility of the inorganic pigment (D) in the (meth) acrylic resin composition, a method of improving the wettability by physically or chemically treating the surface of the inorganic pigment, Known methods such as a method of improving the dispersibility by refining particles aggregated by mechanical dispersion treatment by shearing, and a method of kneading with an arbitrary resin component to form a processed pigment can be used.

The dispersed particle diameter of the inorganic pigment (D) in the (meth) acrylic resin composition is not particularly limited, but can be in the range of 0.1 μm to 10 μm. If the lower limit of the dispersed particle diameter is 0.1 μm or more, it is possible to impart appropriate light diffusibility to the resin molded article, and it is not necessary to excessively contain the inorganic pigment (D), so that high-intensity diffused light is obtained. Therefore, 0.15 μm or more is more preferable. If the upper limit of the dispersed particle diameter is 10 μm or less, the resin molded body is excellent in total light transmittance, so that the brightness can be maintained, and both light transmittance and light diffusibility can be achieved. It is preferable because the flammability can be maintained well.
The “dispersed particle size” is the average particle size of the inorganic pigment particles contained in the resin molded body. After cutting in a direction perpendicular to the surface of the resin molded body, a small piece was cut out using an ultramicrotome (manufactured by Leica, trade name: EM-ULTRACUTUCT). Next, by observing a small piece obtained using a transmission electron microscope (JEM-1011, manufactured by JEOL Ltd., magnification 10,000 times), any resin particle or cross section passing through the vicinity of the center of the resin particle Thirty agglomerated particles were selected, and the maximum particle size of the primary particle size of the resin particles or the secondary particle size of the agglomerated particles was measured and calculated as the average value. In order to judge from an image, it calculated using image analysis software.

  In order to make the dispersed particle diameter of the inorganic pigment (D) in the (meth) acrylic resin composition in the range of 0.1 μm or more and 10 μm or less, the average particle diameter before being contained in the (meth) acrylic resin composition is An inorganic pigment in the range of 0.1 μm to 10 μm may be used. The lower limit of the average particle size is preferably 0.1 μm or more because the dispersibility of the inorganic pigment in the resin molded article is improved. If the upper limit of the average particle diameter of the inorganic pigment is 10 μm or less, it is preferable because the surface appearance of the resin molded article becomes good. The average particle diameter is a measurement of the inorganic pigment (D) alone before being contained in the (meth) acrylic resin composition, and can be measured as a weight average diameter by a Coulter counter method.

<Resin molding>
The resin molding of this invention consists of a (meth) acrylic resin composition mentioned above.
The flame retardancy of the resin molding is generally in a so-called trade-off relationship with the diffusivity, and the flame retardancy tends to decrease as the diffusivity increases. That is, the resin molded body of the present invention is a resin molded body having remarkable characteristics that both flame retardancy and diffusivity, which are opposite characteristics, are compatible.

In the present invention, the value of the diffusivity measured according to DIN 5036 can be used as the diffusivity of the resin molded product. The diffusion rate of the resin molded product of the present invention can be in the range of 60% to 99%. If the lower limit of the diffusivity of the resin molding is 60% or more, it is preferable from the viewpoint of concealing the shape of a light source such as a fluorescent lamp or LED in signboard use or illumination use. Moreover, if the upper limit of a diffusivity is 99% or less, it is preferable from a viewpoint which can ensure sufficient brightness in a signboard use / illumination use. The value of the diffusion rate of the resin molded product can be controlled to a desired value by adjusting the composition of the (meth) acrylic resin composition described later, the type and content of the light diffusing agent, and the like.
The resin molding mentioned above can be manufactured by shape | molding the (meth) acrylic resin composition which satisfy | fills the requirements of this invention by a well-known method, for example.

  Furthermore, the resin molding of this invention has the flame retardance which self-extinguishes within 3 minutes in a JISK6911 flame resistance A method test. If the resin molded body has flame retardance that self-extinguishes within 3 minutes in the above test, it is preferable from the viewpoint of safety because it can prevent the spread of fire and fire in the event of a fire, and it can be used for signboards such as gas stations Suitable for Such a resin molded body can be manufactured by using, for example, a (meth) acrylic resin composition that satisfies the requirements of the present invention.

  Furthermore, the resin molded body of the present invention can have a flame retardancy of V-0 in the vertical combustion test specified by UL94. If the resin molded product has flame resistance of UL94 / V-0 in the above test, it is preferable from the viewpoint of safety because the resin molded product does not continue to burn even if it comes into contact with fire, such as railway vehicles and automobiles. Suitable for use in mobile bodies. Such a resin molded body is, for example, a halogen-containing phosphorus-based flame retardant (C) with respect to 100 parts by mass of the (meth) acrylic polymer (P) in the (meth) acrylic resin composition that satisfies the requirements of the present invention. 15 parts by mass or more and 30 parts by mass or less, and the content of the repeating unit derived from the methacrylic acid ester (M1) contained in the acrylic polymer (P) is 23% by mass or more, derived from the acrylic acid ester (M2). It can manufacture by making content of a repeating unit into 2 mass% or more.

The resin molded body of the present invention can have a heat resistance of a deflection temperature under load (HDT) of 75 ° C. or higher measured according to JIS K 7191. If the resin molded body has a heat resistance of 75 ° C. or higher, it is preferable because the resin molded body can be prevented from being deformed when exposed to a high temperature environment, and is suitable for use in a signboard such as a gas station. Such a resin molded body has, for example, a content of the phosphorus atom-containing compound (C) in the (meth) acrylic resin composition satisfying the requirements of the present invention of 22 parts by mass or less, or an acrylic polymer (P). This is achieved by setting the content of the repeating unit derived from the (meth) acrylic acid ester (M) therein to 45% by mass or less.
Furthermore, in the resin molded body of the present invention, the amount of the halogen-containing phosphorus-based flame retardant (C) is 15 parts by mass or less with respect to 100 parts by mass of the (meth) acrylic polymer (P), and the acrylic polymer (P The content of the repeating unit derived from the (meth) acrylic acid ester (M) contained in ()) is 20% by mass or more, so that the deflection temperature under load (HDT) is 90 ° C. or more. .

Although the shape of this resin molding is not limited, As one Embodiment, it can be set as a plate-shaped resin board. The thickness of the resin plate is not particularly limited, but can be 1 mm or more and 30 mm or less. When the lower limit of the resin plate thickness is 1 mm or more, the strength of the resin molded body can be sufficient. When the upper limit of the thickness of the resin plate is 30 mm or less, the moldability of the resin molded body is good.
The thickness of the resin plate can be measured with a thickness gauge.

<Production method of resin molding>
The manufacturing method of the resin molding of this invention is not specifically limited, For example, it can manufacture using well-known casting polymerization methods, such as the cell cast method mentioned later and the continuous cast method. In the casting polymerization method, the (meth) acrylic resin composition described above is applied to a mold composed of two inorganic glass plates or metal plates (SUS plates) whose periphery is sealed with a gasket such as a resin tube and arranged to face each other at a predetermined interval. (Meth) acrylic resin composition is formed by injecting and polymerizing a polymerizable raw material for obtaining a product, and the obtained (meth) acrylic resin composition is peeled from the mold to obtain a resin molded body. is there.
The casting polymerization template is not particularly limited, and a known template can be used. Examples of the mold for obtaining a plate-shaped resin molded product include a cell casting mold and a continuous casting mold.
As a casting mold for cell casting, for example, two plate-like bodies such as an inorganic glass plate, a chrome-plated metal plate, and a stainless steel plate are arranged to face each other at a predetermined interval, and a gasket is arranged on the edge thereof to form a plate-like body. And a sealed space formed by a gasket.
As a casting mold for continuous casting, for example, a sealed space is formed by opposing surfaces of a pair of endless belts that run in the same direction at the same speed and gaskets that run at the same speed as the endless belt on both sides of the endless belt. Can be mentioned.
As the polymerization method when the casting polymerization method is used, for example, a known method can be used in the same manner as the above-described method for producing an acrylic polymer.
Although the space | interval of the space | gap of a casting_mold | template is suitably adjusted so that the resin board of desired thickness may be obtained, it is 1-30 mm generally.

  Hereinafter, the present invention will be described with reference to examples. In the following, “part” means “part by mass”.

Moreover, the symbol of the compound used by the Example and the comparative example is as follows.
-MMA: methyl methacrylate-IBXMA: isobornyl methacrylate-IBXA: isobornyl acrylate-TBMA: t-butyl methacrylate-BA: n-butyl acrylate-EDMA: ethylene glycol dimethacrylate-CR-570: chlorine-containing condensed phosphorus Acid ester (trade name, manufactured by Daihachi Chemical Industry Co., Ltd.)
TiO2: Commercially available titanium oxide-containing pigment (dispersed particle size: 0.1 to 1.0 μm)
JP508: 2-ethylhexyl acid phosphate (trade name, manufactured by Johoku Chemical Industry Co., Ltd.)
JP504: Butyl acid phosphate (trade name, manufactured by Johoku Chemical Industry Co., Ltd.)

  In addition, the evaluation in an Example and a comparative example was implemented with the following method.

(1) Diffusivity The following evaluation was performed using a plate-shaped resin molded body having a thickness of 3 mm. The resin molded body was installed at a distance of 1.5 m from the lit 45 W fluorescent lamp, and it was evaluated whether the lamp shape of the fluorescent lamp could be confirmed through the resin molded body.
○: The shape of the fluorescent lamp cannot be confirmed.
(Triangle | delta): The lamp shape of a fluorescent lamp can be confirmed very slightly.
X: The lamp shape of the fluorescent lamp can be clearly confirmed.

(2) Diffusivity The following evaluation was performed using a plate-shaped resin molded body having a thickness of 3 mm. Using a variable angle photometer (trade name: GP-200, manufactured by Murakami Color Research Laboratory Co., Ltd.), when light was incident on the sample at 0 °, the sample was 5 °, 20 °, 70 °. The brightness value of transmitted light at an angle was measured, and the diffusivity was calculated.

(3) Flame resistance (JIS)
A test piece of a resin molded body was prepared based on the JIS K 6911 flame resistance A method test, and the time (self-extinguishing time) required until the test piece was self-extinguished was measured.
○: The self-extinguishing time of the test piece is 3 minutes or less.
X: The self-extinguishing time of the test piece exceeds 3 minutes or the test piece does not self-extinguish.

(4) Flame resistance (UL94)
The flame retardancy of the test piece of the resin molded product was evaluated based on the UL94 vertical combustion test method. The determination of flame retardancy was performed based on the criteria shown in Table 1 below.

(5) Heat resistance (HDT)
A test piece of a resin molded body was prepared according to JIS K 7191, and the heat deflection was evaluated by measuring the deflection temperature under load (hereinafter referred to as “HDT”) (° C.).
○: HDT is 90 ° C. or higher.
(Triangle | delta): HDT is less than 90 degreeC.

[Example 1]
(1) Manufacture of syrup Supply a mixture of MMA 75.0 parts, IBXMA 22.0 parts, IBXA 3.0 parts to a reactor (polymerization kettle) equipped with a cooling pipe, a thermometer and a stirrer, and bubble with nitrogen gas while stirring. After that, heating was started. When the internal temperature of the reactor reached 60 ° C., 0.1 part of 2,2′-azobis- (2,4-dimethylvaleronitrile) was added as a radical polymerization initiator, and the internal temperature of the reactor was further increased. After heating to 100 ° C., it was held for 13 minutes. Subsequently, the reactor was cooled until the internal temperature of the reactor reached room temperature to obtain syrup. The content of the polymer in the syrup was 30% by mass and the content of the monomer composition was 70% by mass with respect to the total mass of the syrup.

(2) Cast polymerization 100 parts of the above syrup, 0.15 part of EDMA as monomer (B), 10.5 parts by weight of CR-570 as halogen-containing phosphorus flame retardant (C), and inorganic pigment (D) 0.123 parts of a commercially available titanium oxide-containing pigment and 0.02 parts by mass of JP-508 as a halogen-free phosphate ester (E) were added to obtain a polymerizable composition. Next, the polymerizable composition was poured into a space having a gap of 4.1 mm provided with a vinyl chloride resin gasket disposed at the end of the SUS plate between the two SUS plates facing each other, at 82 ° C. for 30 minutes, Subsequently, it heated at 130 degreeC for 30 minutes, the polymeric composition was hardened, and the (meth) acrylic resin composition was obtained. Table 4 shows the composition of the obtained (meth) acrylic resin composition. Next, after cooling the (meth) acrylic resin composition together with the SUS plate, the SUS plate was removed to obtain a plate-shaped resin molded body having a thickness of 3 mm. The content of the halogen-containing phosphorus-based flame retardant (C) in the resin molded body was 10.5 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer. Table 6 shows the evaluation results of the resin molding. In Tables 6 and 7, “-” means that no measurement was performed.

[Examples 2 to 12]
A (meth) acrylic resin composition and a resin molded body were produced in the same manner as in Example 1 except that the composition of the polymerizable composition was changed as shown in Tables 2 and 3. The composition of the obtained (meth) acrylic resin composition is shown in Tables 4 and 5. Tables 6 and 7 show the evaluation results of the obtained resin moldings.

[Comparative Examples 1-6]
A (meth) acrylic composition and a resin molded body were obtained in the same manner as in Example 1 except that the composition of the polymerizable composition was as shown in Table 3. Table 5 shows the composition of the obtained (meth) acrylic resin composition. Table 7 shows the evaluation results of the obtained resin molding.

The resin molded body obtained in Comparative Example 1 is flame retardant because the (meth) acrylic polymer (P) does not contain a repeating unit derived from a methacrylic ester (M1) and a repeating unit derived from an acrylate (M2). The sex was poor.
The resin molded product obtained in Comparative Example 2 had a low content of the inorganic pigment (D) and had poor diffusibility.
Since the resin molded product obtained in Comparative Example 3 did not contain the halogen-free phosphate ester (E), flame retardancy (JIS) and diffusibility were poor.
The resin molded product obtained in Comparative Example 4 had a low content of halogen-free phosphate ester (E) and had poor flame retardancy (JIS) and diffusibility.
The resin molded product obtained in Comparative Example 5 contained a large amount of inorganic pigment (D) and had poor flame retardancy (JIS).
The resin molded body obtained in Comparative Example 6 has a halogen-containing phosphorus-based flame retardant (C) content of 19.1 parts by mass, but does not contain a halogen-free phosphate ester (E). (JIS) and diffusibility were poor.

  According to the present invention, it is possible to obtain a resin molded body having flame retardancy, heat resistance and appropriate light diffusibility as a signboard / illumination material, and a resin composition for obtaining the resin molded body.

Claims (12)

A (meth) acrylic resin composition containing a (meth) acrylic polymer (P), a halogen-containing phosphorus-based flame retardant (C), an inorganic pigment (D), and a halogen-free phosphate ester (E),
The (meth) acrylic polymer (P) is a repeating unit derived from a methacrylic acid ester (M1) having an aromatic hydrocarbon group or an alicyclic hydrocarbon group having 3 to 20 carbon atoms in the side chain, and aromatic carbonization. Containing a repeating unit derived from an acrylate ester (M2) having a hydrogen group or an alicyclic hydrocarbon group having 3 to 20 carbon atoms in the side chain, and
Content of the said halogen-containing phosphorus flame retardant (C) is 5.0 mass parts or more and 35 mass parts or less with respect to 100 mass parts of said (meth) acrylic polymers (P),
The content of the inorganic pigment (D) is 0.05 parts by mass or more and 0.35 parts by mass or less with respect to 100 parts by mass of the (meth) acrylic polymer (P),
The content of the halogen-free phosphate ester (E) is 0.005 parts by mass or more and 0.15 parts by mass or less with respect to 100 parts by mass of the (meth) acrylic polymer (P). Resin composition.   The (meth) acrylic resin composition according to claim 1, wherein the (meth) acrylic polymer (P) contains a structural unit derived from the monomer (B) having two or more vinyl groups.   The (meth) acrylic resin composition according to claim 1 or 2, wherein the inorganic pigment (D) is titanium oxide. The (meth) acrylic resin composition according to any one of claims 1 to 3, wherein the halogen-free phosphate ester (E) is a compound represented by the following formula (I).

(In the formula (I), R is an alkyl group having 1 to 24 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an aryl group having 1 to 24 carbon atoms, an alkoxy group having 1 to 24 carbon atoms, and 1 to 1 carbon atoms. 24 represents an alkoxycarbonyl group, an alkylcarboxyl group having 1 to 24 carbon atoms, or an alkylene group having 1 to 24 carbon atoms, and n is 1 or 2.)   The (meth) acrylic resin composition according to claim 4, wherein R is an aromatic alkyl group having 4 to 24 carbon atoms or an aliphatic alkyl group having 4 to 24 carbon atoms in the formula (I).   The (meth) acrylic resin composition according to claim 4 or 5, wherein the halogen-free phosphate ester (E) is 2-ethylhexyl acid phosphate. The ratio of the repeating unit derived from the methacrylic acid ester (M1) is 10% by mass to 80% by mass with respect to the total mass of the (meth) acrylic polymer (P),
The ratio of the repeating unit derived from the acrylate ester (M2) is 0.50% by mass or more and 20% by mass or less with respect to the total mass of the (meth) acrylic polymer (P).
The ratio of the structural unit derived from the monomer (B) is 0.05% by mass or more and 0.40% by mass or less with respect to the total mass of the (meth) acrylic polymer (P). (Meth) acrylic resin composition.   The (meta) according to any one of claims 1 to 7, wherein the halogen-containing phosphorus-based flame retardant (C) is at least one selected from the group consisting of a halogen-containing phosphate ester and a halogen-containing phosphonate ester. ) Acrylic resin composition.   The resin molding which consists of a (meth) acrylic resin composition as described in any one of Claims 1-8. A resin molded body that satisfies the following conditions (1) to (3).
Condition (1): Has a flame retardancy that self-extinguishes within 3 minutes when a combustion test is performed in JIS K6911 flame retardancy A method test.
Condition (2): The diffusivity measured by DIN 5036 is 90% or more and 99% or less.
Condition (3): The deflection temperature under load measured in accordance with JIS K 7191 is 75 ° C. or higher.   The resin molded product according to claim 9 or 10, wherein a deflection temperature under load measured in accordance with JIS K 7191 is 90 ° C or higher.   The resin molding as described in any one of Claims 9-11 which has a flame retardance of V-0 in the vertical combustion test prescribed | regulated by UL94.