JP3606970B2 - Melamine phosphate and flame retardant - Google Patents

Description

（式中、Ｒは置換基を有していてもよいアルキル基，ｍは０〜２の整数、ｎおよびｐはそれぞれ１〜３の整数を示す）で表され、米国特許第３２９３３２７号明細書、米国特許第３８７３４９６号明細書、特開昭５８−１７１２６号公報などに記載されている。
アルキル基には、例えば、直鎖又は分岐鎖状のＣ_１−３０アルキル基（例えば、Ｃ_１−２０アルキル基）、好ましくは直鎖又は分岐鎖状のＣ_１−２４アルキル基などが含まれ、これらのアルキル基は、ヒドロキシル基、Ｃ_１−４アルコキシ基、カルボキシル基、Ｃ_１−４アルコキシ−カルボニル基、Ｃ_１−４アシル基などの置換基が置換していてもよい。ｍ、ｎおよびｐは、通常、それぞれ１又は２（特に１）である場合が多い。
【００２３】
前記ビシクロリン酸エステルには、例えば、２，６，７−トリオキサ−１−ホスホビシクロ（２，２，２）オクタン−１−オキシド、２，６，７−トリオキサ−１−ホスホビシクロ（２，２，２）オクタン−４−メチル−１−オキシド、２，６，７−トリオキサ−１−ホスホビシクロ（２，２，２）オクタン−４−エチル−１−オキシド、２，６，７−トリオキサ−１−ホスホビシクロ（２，２，２）オクタン−４−ヘキシル−１−オキシド、２，６，７−トリオキサ−１−ホスホビシクロ（２，２，２）オクタン−４−ヘキサデシル−１−オキシドなどの２，６，７−トリオキサ−１−ホスホビシクロ（２，２，２）オクタン−４−アルキル−１−オキシド；２，６，７−トリオキサ−１−ホスホビシクロ（２，２，２）オクタン−４−ニトロ−１−オキシド、２，６，７−トリオキサ−１−ホスホビシクロ（２，２，２）オクタン−４−アミノ−１−オキシド、２，６，７−トリオキサ−１−ホスホビシクロ（２，２，２）オクタン−４−メタノール−１−オキシド、２，８，９−トリオキサ−１−ホスホビシクロ（３，３，１）ノナン−５−メチル−１−オキシド、２，６，７−トリオキサ−１−ホスホビシクロ（２，２，１）ヘプタン−４−ヘキサデシル−１−オキシドなどが含まれる。これらのビシクロリン酸エステルは、単独で又は二種以上組み合わせて使用できる。好ましいビシクロリン酸エステルには、２，６，７−トリオキサ−１−ホスホビシクロ（２，２，２）オクタン−４−メタノール−１−オキシドなどが含まれる。
ビシクロリン酸エステルの使用量は、例えば、前記リン酸メラミン１００重量部に対して１〜２００重量部、好ましくは５〜１００重量部、さらに好ましくは１０〜８０重量部（例えば、２０〜５０重量部）程度である。
【００２４】
前記多価アルコールには、複数のヒドロキシル基（例えば、３又は４以上のヒドロキシル基）を有する環状又は非環状化合物、例えば、ペンタエリスリトール、ジペンタエリスリトール、トリペンタエリスリトール、ペンチトール類（アドニトール、アラビトールなど）、ヘキシトール類（ズルシトール、イノシトールなど）、およびサッカリド類（アミロース、キシランなど）およびこれらの誘導体（例えば、Ｎ−メチルグルカミンなど）などが含まれる。これらの多価アルコールは単独で又は二種以上混合して使用できる。好ましい多価アルコールにはペンタエリスリトール、ジペンタエリスリトールなどが含まれる。
多価アルコールの使用量は、例えば、リン酸メラミン１００重量部に対して１〜２００重量部、好ましくは５〜１５０重量部、さらに好ましくは１０〜１００重量部（例えば、２０〜５０重量部）程度である。
【００２５】
前記難燃剤は、さらにシリコーンオイルを含んでいてもよい。シリコーンオイルには、種々のポリシロキサンが含まれ、例えば、流動性シリコーンおよびシリコーンガムのいずであってもよい。シリコーンオイルには、例えば、ポリジメチルシロキサンなどのポリジアルキルシロキサン、ポリジフェニルシロキサンなどのポリジアリールシロキサン、ポリメチルフェニルシロキサンなどのポリアルキルアリールシロキサンなどが含まれる。シリコーンオイルのケイ素原子には、水素原子、ヒドロキシル基、アルコキシ基、アリール基、ビニル基又はアリル基などが結合していてもよい。これらのシリコーンオイルは単独で又は二種以上混合して使用できる。好ましいシリコーンオイルにはポリジメチルシロキサンが含まれる。シリコーンオイル（オルガノポリシロキサン）の粘度は、例えば、温度２５℃で６００〜３００，０００，０００センチポイズ、好ましくは１０，０００〜２００，０００センチポイズ、さらに好ましくは９０，０００〜１５０，０００センチポイズ程程度である。
シリコーンオイルの使用量は、例えば、リン酸メラミン１００重量部に対して０〜１００重量部、好ましくは５〜８０重量部、さらに好ましくは１０〜７０重量部（例えば、２０〜５０重量部）程度である。
なお、必要に応じて、上記シリコーンオイルとともに、又はシリコーンオイルを用いることなく、シリコーン樹脂を用いてもよい。
【００２６】
さらに、リン酸メラミンは、有機リン酸エステル及びモリブデン化合物のうち好くなくとも一方の成分と組み合わせることにより難燃剤としてもよい。
有機リン酸エステル（非環状ホスフェート系難燃剤）には、モノホスフェート、ジホスフェートおよびトリホスフェートが含まれ、トリホスフェートが好ましい。有機リン酸エステルには縮合したリン酸エステルも含まれる。有機リン酸エステルには、トリフェニルホスフェート、トリキシレニルホスフェートなどのなどのトリアリールホスフェート、イソプロピルトリフェニルホスフェートなどのアルキルアリールホスフェート、トリブチルホスフェートなどのトリアルキルホスフェートなどが含まれる。これらの有機リン酸エステルは一種又は二種以上混合して使用できる。好ましい有機リン酸エステルには、トリアリールホスフェート（トリフェニルホスフェート、炭素数１〜４程度の低級アルキル基がベンゼン環に１〜３個程度置換したトリフェニルホスフェートなど）が含まれる。
リン酸エステルの使用量は、例えば、リン酸メラミン１００重量部に対して０〜２００重量部、好ましくは５〜１５０重量部、さらに好ましくは１０〜１００重量部（例えば、２０〜５０重量部）程度である。
【００２７】
モリブデン化合物には、例えば、三酸化モリブデンなどの酸化物、二硫化モリブデンなどの硫化物、ジモリブデン酸アンモニウム、モリブデン酸カルシウム、モリブデン酸亜鉛、モリブデン酸カリウム、モリブデン酸ナトリウムなどのモリブデン酸塩などが含まれる。これらの化合物も一種又は二種以上使用できる。モリブデン化合物としては三酸化モリブデンなどの酸化物を用いる場合が多い。 モリブデン化合物の使用量は、例えば、前記リン酸メラミン１００重量部に対して０〜５０重量部、好ましくは０．０１〜２５重量部（例えば、０．０５〜２０）重量部、さらに好ましくは０．１〜１０重量部（例えば、０．５〜５重量部）程度である。
【００２８】
前記難燃剤は、さらにフッ素含有樹脂などを含んでいてもよい。フッ素含有樹脂としては、例えば、ポリテトラフルオロエチレン、ポリフッ化ビニリデン、テトラフルオロエチレン−ヘキサフルオロプロピレン共重合体、エチレン−テトラフルオロエチレン共重合体、エチレン−ヘキサフルオロプロピレン共重合体などが挙げられる。これらのフッ素含有樹脂のフッ素含有量は、６５〜７６重量％、好ましくは７０〜７６重量％程度である。また、フッ素含有樹脂の密度は１．２〜２．３ｇ／ｃｍ^３程度である場合が多い。
フッ素含有樹脂は、通常、粉粒状で使用され、フッ素含有樹脂の粒径は、例えば、平均粒径０．０５〜１０００μｍ、好ましくは０．０５〜１００μｍ、さらに好ましくは０．０８〜２０μｍ程度である。
フッ素含有樹脂の使用量は、ドリッピングを抑制できる範囲で選択でき、例えば、前記リン酸メラミン１００重量部に対して０〜５０重量部、好ましくは０．０１〜２５重量部（例えば、０．０５〜２０）重量部、さらに好ましくは０．１〜１０重量部（例えば、０．５〜５重量部）程度である。
【００２９】
好ましい難燃剤の組み合わせには、（１）リン酸メラミンとビシクロリン酸エステル及び／又は多価アルコールとの組み合わせ、（２）リン酸メラミンとビシクロリン酸エステル及び／又は多価アルコールとシリコーンオイルとの組み合わせ、（３）前記（１）及び（２）の成分に加えて、さらにモリブデン化合物、リン酸エステルおよびフッ素含有樹脂から選ばれた少なくとも一種の成分を添加した組み合わせなどが含まれる。なお、前記（３）の組み合わせにおいては、モリブデン化合物およびリン酸エステルの少なくともいずれか一方を添加する場合が多い。また、フッ素含有樹脂の添加は、溶融軟化に伴うドリッピングを防止するために有効である。
【００３０】
本発明のリン酸メラミンおよび難燃剤は、種々の樹脂を難燃化する上で有用である。前記樹脂としては、例えば、ポリエチレン、ポリプロピレンなどのポリオレフィン、ポリブタジエンなどのジエン系ポリマー、ポリ塩化ビニルなどのビニル樹脂、ポリメタクリル酸メチルなどのアクリル樹脂、スチレン系樹脂、ポリエチレンテレフタレート、ポリブチレンテレフタレートなどのポリエステル、ポリアミド６，ポリアミド６６などのポリアミド、ポリカーボネート、熱可塑性ポリウレタン、ポリフェニレンオキサイド、ポリエーテル、ポリアセタール、ポリフェニレンエーテル、ポリスルホン、ポリエーテルスルホン、ポリエーテルイミド、ポリアミドイミドなどの熱可塑性樹脂のみならず、エポキシ樹脂、ビニルエステル樹脂、フェノール樹脂、アミノ樹脂（尿素樹脂、メラミン樹脂など）、熱硬化性ポリウレタン、不飽和ポリエステル、ポリイミドなどの熱硬化性樹脂が挙げられる。
【００３１】
本発明のリン酸メラミンおよび難燃剤は、好ましくは熱可塑性樹脂、特にスチレン系樹脂の難燃化に有用である。
スチレン系樹脂には、スチレン、α−メチルスチレン、ビニルトルエンなどのスチレン系単量体の単独重合体又は共重合体、スチレン系単量体とビニル単量体（アクリロニトリル、メタクリル酸メチルなどの（メタ）アクリル系単量体、無水マレイン酸など）との共重合体、ゴム成分Ｘ（例えば、ポリブタジエンなどのジエン系ゴム、エチレン／プロピレン系ゴム、アクリル系ゴムなど）の存在下、スチレン系単量体とビニル単量体（アクリロニトリルなど）とをグラフト重合させたグラフト重合体、スチレン系ブロック共重合体などが含まれる。スチレン系樹脂としては、例えば、ポリスチレン、スチレン−メタクリル酸メチル共重合体、スチレン−無水マレイン酸共重合体、アクリロニトリル−スチレン共重合体（ＡＳ樹脂）、耐衝撃性ポリスチレン、スチレン系グラフト重合体であるＡＸＳ樹脂（ゴム成分がポリブタジエンであるＡＢＳ樹脂、ゴム成分がアクリルゴムであるＡＡＳ樹脂、ゴム成分がエチレン−プロピレンゴム（ＥＰＤＭ）であるＡＥＳ樹脂など）、スチレン系ブロック共重合体（例えば、スチレン−ブタジエン−スチレン（ＳＢＳ）共重合体、スチレン−イソプレン−スチレン（ＳＩＳ）共重合体、スチレン−エチレン−ブチレン−スチレン（ＳＥＢＳ）共重合体など）などが挙げられる。好ましいスチレン系樹脂には、ポリスチレン、アクリロニトリル−スチレン共重合体、耐衝撃性ポリスチレン、ＡＢＳ樹脂などのＡＸＳ樹脂、スチレン系ブロックコポリマーが含まれる。これらのスチレン系樹脂は一種又は二種以上混合して使用できる。
【００３２】
本発明のリン酸メラミンおよび難燃剤は、前記樹脂に対して難燃性を付与できる広い範囲で添加できる。リン酸メラミンの添加量は、樹脂１００重量部に対して１〜１００重量部、好ましくは５〜７５重量部、さらに好ましくは１０〜５０重量部（例えば、２０〜４０重量部）程度である。難燃剤をリン酸メラミンと他の成分とで構成する場合、難燃剤の使用量は、難燃剤の構成成分に応じて、樹脂１００重量部に対して１〜１５０重量部、好ましくは５〜１２５重量部、さらに好ましくは１０〜１００重量部（例えば、２０〜７０重量部）程度である。
【００３３】
リン酸メラミンや前記難燃剤を含む樹脂組成物は、前記樹脂とリン酸メラミン又は難燃剤とを乾湿又は湿式混合したり、溶融混練することにより調製できる。樹脂組成物には、慣用の添加剤、例えば、酸化防止剤、紫外線吸収剤、耐光安定剤などの安定化剤、可塑剤、帯電防止剤、滑剤、充填剤、耐衝撃改良剤、充填剤、補強剤、着色剤、色相改良剤などを添加してもよい。前記樹脂組成物は、押出し成形、射出成形などの種々の成形法により成形品を製造する上で有用である。
【００３４】
【発明の効果】
本発明のリン酸メラミンは、示差熱分析における特定の吸熱特性やＸ線回折スペクトルを示し、スチレン系樹脂などの種々の樹脂に高い難燃性を付与できる。また、非ハロゲン系化合物であるため、リン酸メラミンは、腐食性や有毒性ガスを発生することがないだけでなく、難燃性が高い。そのため、比較的少量の添加により難燃性を高めることができる。
【００３５】
【実施例】
以下に、実施例に基づいて本発明をより詳細に説明するが、本発明はこれらの実施例により限定されるものではない。
実施例１
撹拌機、還流冷却管、および温度計を備えたジャケット付き反応器に、メラミン１００ｇ（０．７９モル）および水３５００ｇを仕込んだ後、撹拌下、９０℃に昇温した。次いで、８５重量％オルトリン酸水溶液９１．５ｇ（０．７９モル）を３０分かけて滴下し、９０℃で１時間反応させた。反応混合液を２５℃に冷却し、スリラー状の反応混合液を取出して濾過することにより白色結晶が得られた。この結晶を水２００ｇで水洗し、濾過することにより白色のリン酸メラミンの湿結晶１９５ｇが得られた。この湿結晶を熱風乾燥機にて１８０℃で２時間乾燥することにより、リン酸メラミン１４０ｇが得られた。
図１に得られたリン酸メラミンの示差熱分析曲線、図６にＸ線回折スペクトルを示す。
【００３６】
実施例２
撹拌機、還流冷却管、および温度計を備えたジャケット付き反応器に、メラミン１００ｇ（０．７９モル）および水３５００ｇを仕込んだ後、撹拌下、９５℃に昇温した。次いで、８５重量％オルトリン酸水溶液９１．５ｇ（０．７９モル）を１５分かけて滴下し、還流下で１時間反応させた。反応混合液を２５℃に冷却し、スリラー状の反応混合液を取出して濾過することにより白色結晶が得られた。この結晶を水２００ｇで水洗し、濾過することにより白色のリン酸メラミンの湿結晶１９８ｇが得られた。この湿結晶を熱風乾燥機にて２００℃で１時間乾燥することにより、リン酸メラミン１３８ｇが得られた。
実施例３
実施例２と同様の反応条件及び後処理により得られたリン酸メラミンの湿結晶１９５ｇを、撹拌式減圧乾燥機を用いて、ジャケット温度９０℃、１ｔｏｒｒで１０時間乾燥することにより、リン酸メラミン１３７ｇを得た。図２に得られたリン酸メラミンの示差熱分析曲線、図７にＸ線回折スペクトルを示す。
【００３７】
実施例４
撹拌機、還流冷却管、および温度計を備えたジャケット付き反応器に、メラミン１００ｇ（０．７９モル）および水３０００ｇを仕込んだ後、撹拌下、９５℃に昇温した。次いで、８５重量％オルトリン酸水溶液８２．４ｇ（０．７１モル）を１５分かけて滴下し、還流下で１５分間反応させた。反応混合液を２５℃に冷却し、スリラー状の反応混合液を取出して濾過することにより白色のリン酸メラミンの湿結晶２００ｇが得られた。この湿結晶を熱風乾燥機にて１５０℃で２時間乾燥することにより、リン酸メラミン１４１ｇが得られた。
【００３８】
実施例５
撹拌機、還流冷却管、および温度計を備えたジャケット付き反応器に、メラミン１００ｇ（０．７９モル）および水２０００ｇを仕込んだ後、撹拌下、９５℃に昇温した。次いで、８５重量％オルトリン酸水溶液７３．２ｇ（０．６３モル）を１５分かけて滴下し、還流下で１５分間反応させた。反応混合液を２５℃に冷却し、スリラー状の反応混合液を取出して濾過することにより白色のリン酸メラミンの湿結晶１９２ｇが得られた。この湿結晶を熱風乾燥機にて１５０℃で２時間乾燥することにより、リン酸メラミン１３５ｇが得られた。
【００３９】
比較例１
撹拌機、還流冷却管、および温度計を備えたジャケット付き反応器にメラミン１００ｇ（０．７９モル）および水３５００ｇを仕込んだ後、９０℃に昇温した。次いで、８５重量％オルトリン酸水溶液１０１ｇ（０．８８モル）を３０分間かけて滴下し、９０℃で１時間反応させた。反応混合液を２５℃に冷却し、スリラー状の反応混合液を取出して濾過することにより白色結晶が得られた。この結晶を水２００ｇで水洗し、濾過することにより、白色のリン酸メラミンの湿結晶２２３ｇが得られた。この湿結晶を１８０℃で２時間乾燥することにより、リン酸メラミン１５３ｇが得られた。図３にリン酸メラミンの示差熱分析曲線、図８にＸ線回折スペクトルを示す。
【００４０】
比較例２
撹拌機、還流冷却管、および温度計を備えたジャケット付き反応器にメラミン１００ｇ（０．７９モル）および水３５００ｇを仕込んだ後、９０℃に昇温した。次いで、８５重量％オルトリン酸水溶液１３７ｇ（１．１９モル）を３０分間かけて滴下し、９０℃で１時間反応させた。反応混合液を２５℃に冷却し、スリラー状の反応混合液を取出して濾過することにより白色結晶が得られた。この結晶を水２００ｇで水洗し、濾過することにより、白色のリン酸メラミンの湿結晶２０３ｇが得られた。この湿結晶を１８０℃で２時間乾燥することにより、リン酸メラミン１５５ｇが得られた。図４にリン酸メラミンの示差熱分析曲線、図９にＸ線回折スペクトルを示す。
【００４１】
比較例３
市販品のリン酸メラミン（三和ケミカル（株）製，商品名ＭＰＰ−Ａ）を用いた。図５にリン酸メラミンの示差熱分析曲線、図１０にＸ線回折スペクトルを示す。
【００４２】
［熱分析及びＸ線回折］
そして、前記実施例及び比較例で得られたリン酸メラミンの示差熱分析を、熱重量−示差熱測定装置（リガク（株）製，サーモフレックス８１１０）を用いて室温から５００℃まで１０℃／分の昇温速度で行なった。表１に、観測された吸熱ピークのうち、主要な３つのピークの観測位置（温度℃）を示す。
また、前記リン酸メラミンのＸ線回析スペクトルを、Ｘ線回析装置（リガク（株）製，ＲＩＮＴ−１５００）を用いて測定した。表１に、観測された回析ピークのうち、最大強度を示すピークから順に、上位３本の主要ピークの回析角２θ（°）を示す。
【００４３】
［難燃性］
さらに、前記リン酸メラミンの難燃剤としての評価を下記の要領で行った。すなわち、耐衝撃性ポリスチレン（ＨＩＰＳ，ポリブタジエン含量９重量％，ポリスチレンの重量平均分子量２３×１０^４）１００重量部に、前記リン酸メラミン３０重量部、ジペンタエリスリトール１０重量部および２，６，７−トリオキサ−１−ホスホビシクロ（２，２，２）オクタン−４−メタノール−１−オキシド１０重量部を添加してタンブラーブレンダーで混合した後、押出機にて溶融混練し、ペレット状の樹脂組成物を得た。射出成形機（シリンダー温度２００℃、金型温度５０℃）を用い、得られたペレット状樹脂組成物から一般物性用試験片を作製し、次のようにして、試験片の特性を測定した。結果を表１に示す。
【００４４】
（１）難燃性
米国ＵＬ規格に規定されている垂直燃焼性試験（９４Ｖ−０）に準拠し、厚み１／８インチの試験片の難燃性を評価した。
（２）耐衝撃強度
厚み１／４インチの試験片についてノッチ無しのアイゾット衝撃強度を評価した。
【００４５】
【表１】

表１から明らかなように、実施例で得られたリン酸メラミンを用いると、耐衝撃性などに悪影響を及ぼすことなく、耐炎性を格段に改善でき、高い難燃性を樹脂に付与できる。
【図面の簡単な説明】
【図１】図１は実施例１で得られたリン酸メラミンの示差熱分析曲線を示す図である。
【図２】図２は実施例３で得られたリン酸メラミンの示差熱分析曲線を示す図である。
【図３】図３は比較例１で得られたリン酸メラミンの示差熱分析曲線を示す図である。
【図４】図４は比較例２で得られたリン酸メラミンの示差熱分析曲線を示す図である。
【図５】図５は比較例３のリン酸メラミンの示差熱分析曲線を示す図である。
【図６】図６は実施例１のリン酸メラミンのＸ線回折スペクトルを示す図である。
【図７】図７は実施例３のリン酸メラミンのＸ線回折スペクトルを示す図である。
【図８】図８は比較例１のリン酸メラミンのＸ線回折スペクトルを示す図である。
【図９】図９は比較例２のリン酸メラミンのＸ線回折スペクトルを示す図である。
【図１０】図１０は比較例３のリン酸メラミンのＸ線回折スペクトルを示す図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to melamine phosphate useful as a flame retardant.
[0002]
[Prior art]
Conventionally, halogen-containing compounds represented by decabromodiphenyl ether have been added as a method for imparting flame retardancy to styrene-based thermoplastic resins. However, halogen-containing compounds generate toxic gases that are highly corrosive during molding or combustion.
[0003]
In recent years, with increasing interest in environmental problems, a method for making a thermoplastic resin flame retardant without using a halogen-containing compound has been studied as a method for solving these drawbacks. As a representative example, it has been proposed to add a phosphate compound such as an organic phosphate, red phosphorus, or a nitrogen-containing phosphate as a flame retardant. For example, JP-A-58-17126 discloses a resin selected from polyolefin, polyvinyl aromatic resin, polycarbonate, polyacrylate, polyamide, polyvinyl chloride, 2,6,7-trioxa-1-phosphobicyclo. [2.2.2] A foamable flame retardant composition containing nitrogen compounds such as 1-octane-4-methanol-1-oxide and melamine phosphate has been proposed. Japanese Patent Application Laid-Open No. 64-14277 includes 100 parts by weight of a thermoplastic resin, 2 to 30 parts by weight of a flame retardant additive, and includes 20 to 60% by weight of silicone oil and 10% of silicone resin. Disclosed is a composition composed of ˜40 wt% and a gas generating agent consisting of 5 to 60 wt% of a compound containing phosphorus and nitrogen. In this document, melamine pyrophosphate is exemplified as the gas generating agent, and it is described that the flame retardant additive may further contain a polyhydric alcohol with respect to the gas generating agent.
[0004]
Furthermore, melamine phosphate, which is one of the nitrogen-containing phosphates, is used as a flame retardant for nitrogen-containing and oxygen-containing polymers such as polyurethane and polyamide. The shape and composition of the melamine phosphate vary greatly depending on the production method, and the melamine phosphate that has been heat-treated at a temperature of 210 ° C. for at least 5 hours is a plate crystal. It has been reported that the flame retardancy is improved when added in an amount of 30% by weight or 30% by weight (M. Kay and A. F. Price, Fire and Materials, Vol. 6, No. 3, 119-121, 1982). However, even if the melamine phosphate is added to a thermoplastic resin such as a styrene resin, it is difficult to greatly improve the flame retardancy. In addition, in order to impart high flame retardancy, it is necessary to add a large amount of melamine phosphate, but the addition of a large amount of flame retardant deteriorates the mechanical properties of the resin composition.
[0005]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide melamine phosphate that can impart high flame retardancy to various resins such as styrene resins.
Another object of the present invention is to provide melamine phosphate that is highly flame retardant and does not generate corrosive or toxic gases.
Still another object of the present invention is to provide a melamine phosphate which can enhance the flame retardancy by adding a relatively small amount.
[0006]
[Means for Solving the Problems]
As a result of intensive investigations to achieve the above object, the present inventors have found that the crystal structure of melamine phosphate has a great influence on flame retardancy, and when a specific melamine phosphate is used for a thermoplastic resin. On the other hand, it was found that extremely high flame retardancy can be imparted, and the present invention was completed.
That is, the melamine phosphate of the present invention is a reaction product of melamine and phosphoric acid, and (1) the endothermic region is 290 ± 10 ° C. when measured by a differential thermal analysis method at a heating rate of 10 ° C./min. (First endothermic region), 320 ± 10 ° C. (second endothermic region) and 390 ± 10 ° C. (third endothermic region).
The melamine phosphate of the present invention has (2) X-ray diffraction spectrum with diffraction angles 2θ of 17.5 ± 0.5 °, 19.3 ± 0.5 ° and 24.9 ± 0.5 °. Also included is melamine phosphate in which a peak is observed in the region.
In the melamine phosphate, (3) the atomic ratio (N / P) of nitrogen (N) to phosphorus (P) is about 6.2 to 7.8.
[0007]
Furthermore, the melamine phosphate of the present invention includes a melamine phosphate which is a reaction product of melamine and phosphoric acid and has the characteristics (1), (2) and (3). That is, this melamine phosphate has the following characteristics.
(1) An endothermic region is observed in the temperature range of 290 ± 10 ° C., 320 ± 10 ° C., and 390 ± 10 ° C. when measured at 10 ° C./min by a differential thermal analysis method.
(2) In the X-ray diffraction spectrum, peaks are observed in the regions of diffraction angles 2θ = 17.5 ± 0.5 °, 2θ = 19.3 ± 0.5 ° and 2θ = 24.9 ± 0.5 °. Is observed
(3) The atomic ratio (N / P) of nitrogen (N) and phosphorus (P) is 2.8 to 3.5.
The present invention further discloses a flame retardant composed of the melamine phosphate.
In the present specification, “melamine phosphate” means a reaction product of melamine and phosphoric acid, and includes a salt of melamine and phosphoric acid. “Phosphoric acid” means orthophosphoric acid unless otherwise specified.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The first melamine phosphate of the present invention is characterized by (1) three endothermic regions, that is, 290 ± 10 ° C. (for example, 290 ± 7) when measured at a temperature rising rate of 10 ° C./min according to differential thermal analysis. A first endothermic region of about 320 ° C. (for example, about 320 ± 7 ° C.) and a third endothermic region of about 390 ± 10 ° C. (for example, about 390 ± 7 ° C.). It is at a point to be observed. In differential thermal analysis, the height of the endothermic peak in the first endothermic region is Ph1, the endothermic peak height in the second endothermic region is Ph2, and the endothermic peak height in the third endothermic region. Is Ph3, the endothermic peaks are in the order of Ph1 <Ph2 <Ph3. In particular, a sharp endothermic peak is shown in the second endothermic region and the third endothermic region, a sharp endothermic peak is shown in the first endothermic region (temperature region), and a broad or moderate endothermic behavior is exhibited.
[0009]
The endothermic peaks in the first endothermic region, the second endothermic region, and the third endothermic region are, for example, the second endothermic when the intensity of the peak Ph3 in the third endothermic region from the baseline is 100. The endothermic peak Ph2 has a strength (intensity ratio) of about 25 to 70 (for example, 25 to 65), preferably about 30 to 60 (for example, 30 to 50). In many cases, the endothermic peak Ph1 has a strength (intensity ratio) of about 5 to 40 (for example, 10 to 40), preferably about 10 to 30 (for example, 15 to 25).
[0010]
The feature of the second melamine phosphate according to the present invention is that (2) in the diffraction spectrum by X-ray diffraction using Cu-Ka line, the diffraction angle 2θ = 17.5 ± 0.5 ° (first Region), 2θ = 19.3 ± 0.5 ° (second region) and 2θ = 24.9 ± 0.5 ° (third region). The intensity of the peaks Px1, Px2, and Px3 in each region in the diffraction spectrum is smaller in the order of the first region peak Px1> the third region peak Px3> the second region peak Px2.
[0011]
Further, among all the peaks appearing in the X-ray diffraction spectrum, the peak Px1 in the first region shows the maximum intensity, and the peak Px3 in the third region shows the intensity at the second or third position. Has a pattern. In the diffraction spectrum, the peak Px3 in the third region often shows the second-order intensity.
When the intensity of the peak Px1 in the first region is 100, the intensity (intensity ratio) of the peak Px3 in the third region is about 45 to 80 (preferably about 55 to 70). The intensity (intensity ratio) of the peak Px2 is about 30 to 65 (preferably about 40 to 60).
[0012]
In the melamine phosphate of the present invention, (3) the atomic ratio (N / P) of nitrogen (N) to phosphorus (P) is, for example, 6.2 to 7.8, preferably 6.4 to 7.5. More preferably, it is about 6.6 to 7.4 (for example, 6.6 to 7.2).
[0013]
Furthermore, the melamine phosphate of the present invention includes melamine phosphate having the characteristics (1) to (3), particularly melamine phosphate having the following characteristics.
(1) When measured by differential thermal analysis at a rate of temperature increase of 10 ° C./min, the endothermic peak is the endothermic peak Ph1 in the first endothermic region <endothermic peak Ph2 in the second endothermic region <third endothermic. Endotherm peak in the order of Ph3, showing a sharp or broad endothermic peak in the first endothermic region (temperature region),
(2) In an X-ray diffraction spectrum, a peak Px1 at a diffraction angle 2θ = 17.5 ± 0.5 °, a peak Px2 at 1θ ± 19.3 ± 0.5 °, and 2θ = 24.9 ± 0.5 The peak Px3 at 0 °, the peak Px1 shows the maximum intensity in the diffraction spectrum, the peak Px3 shows the second or third intensity in the diffraction spectrum,
(3) The atomic ratio (N / P) of nitrogen (N) to phosphorus (P) is 6.2 to 7.8.
[0014]
Melamine phosphate exhibiting such characteristics, particularly the differential thermal characteristics and X-ray diffraction spectrum, is greatly different from the characteristics of commercially available melamine phosphate. As is apparent from the examples described later, the melamine phosphate of the present invention exhibits high flame retardancy that cannot be expected from melamine phosphate that does not exhibit the above-mentioned properties.
[0015]
The specific melamine phosphate can be produced, for example, by reacting melamine and phosphoric acid at a specific ratio and drying the reaction product.
Examples of phosphoric acid include orthophosphoric acid, pyrophosphoric acid, metaphosphoric acid, triphosphoric acid, tetraphosphoric acid, polyphosphoric acid, phosphorous acid, and the like. These phosphoric acids can be used alone or in combination of two or more. As phosphoric acid, orthophosphoric acid is often used. In addition, melamine phosphate is not only a direct reaction between melamine and phosphoric acid, but also an indirect method via an intermediate, for example, a reaction product of melamine and hydrochloric acid or acetic acid (for example, melamine acetate) It can also be obtained by reaction with a phosphate such as sodium dihydrogen phosphate.
The amount of phosphoric acid used is, in terms of orthophosphoric acid, 0.6 to 1.1 mol, preferably 0.7 to 1.05 mol, more preferably about 0.8 to 1.0 mol with respect to 1 mol of melamine. It is.
[0016]
Melamine and phosphoric acid may be charged into the reactor at the same time, or phosphoric acid may be added continuously or stepwise to the melamine previously charged into the reactor by a method such as dropping. The concentration of phosphoric acid is not particularly limited, and an aqueous phosphoric acid solution of about 75 to 89% by weight that is easily available industrially may be used, or an aqueous solution diluted to an appropriate concentration with water may be used. In addition, various reactors, such as a tank reactor and a tube reactor, can be employed as the reactor, and the reaction type may be any of batch type, semi-batch type, continuous type, and the like.
[0017]
The reaction between melamine and phosphoric acid may be performed in the absence of a solvent or in the presence of a solvent that does not impair the reaction. As the solvent, a solvent such as water and / or a hydrophilic solvent (for example, a water-soluble alcohol, a water-soluble ketone, a water-soluble ether, etc.) may be used. The reaction is usually carried out in the presence of water.
The reaction temperature can be selected from an appropriate range, and is, for example, 0 to 200 ° C., preferably about 20 to 150 ° C. (for example, about 50 to 120 ° C.), and the reaction may be performed under normal pressure or increased pressure. Further, the reaction time is not particularly limited, but is usually 15 minutes or longer (for example, about 15 minutes to 12 hours) in many cases.
[0018]
From the reaction mixture produced by such a reaction, melamine phosphate is usually precipitated as crystals. Therefore, melamine phosphate can be easily separated from the solvent by conventional separation means such as filtration and centrifugation. The separated melamine phosphate may be washed by a method such as washing with water.
[0019]
The melamine phosphate thus obtained is a wet crystal and contains a small amount of solvent (usually water). In order to remove this solvent, the wet crystalline melamine phosphate is subjected to a heat drying treatment.
In the drying process, the drying method and the type of the dryer are not particularly limited. The heat transfer type may be any of convection heat transfer (so-called hot air drying), conduction heat transfer, radiant heat transfer, microwave type, and the like. The drying temperature is not particularly limited. Usually, when a dryer of a type such as convection heat transfer or conduction heat transfer is used, the temperature is 50 to 205 ° C., preferably 90 to 200 ° C. (for example, 150 to 200 ° C.). Degree. Although drying is often performed at normal pressure, it may be performed under reduced pressure. The drying time is not particularly limited, but in order to increase production efficiency, it is often a relatively short time, for example, about 10 minutes to 3 hours, preferably about 30 minutes to 2 hours.
[0020]
The resin composition containing melamine phosphate thus obtained exhibits extremely excellent flame retardancy. Therefore, the melamine phosphate of the present invention is useful as a flame retardant.
The flame retardant should just contain the said melamine phosphate at least. That is, the flame retardant may be composed of the melamine phosphate alone or in combination with other flame retardants (particularly non-halogen flame retardants). For example, in order to further enhance the flame retardancy due to melamine phosphate, it may be used as a flame retardant in combination with at least one component of, for example, a bicyclophosphate ester (bicyclic phosphate) and a polyhydric alcohol.
[0021]
The bicyclophosphate ester has the following formula (I)
[0022]
[Chemical 1]

Wherein R is an alkyl group which may have a substituent, m is an integer of 0 to 2, and n and p are each an integer of 1 to 3, and U.S. Pat. No. 3,293,327 U.S. Pat. No. 3,873,496, JP-A-58-17126, and the like.
The alkyl group includes, for example, linear or branched C _1-30 An alkyl group (eg C _1-20 Alkyl group), preferably linear or branched C _1-24 Alkyl groups and the like, and these alkyl groups include hydroxyl group, C _1-4 Alkoxy group, carboxyl group, C _1-4 Alkoxy-carbonyl group, C _1-4 A substituent such as an acyl group may be substituted. In many cases, m, n and p are usually 1 or 2 (particularly 1), respectively.
[0023]
Examples of the bicyclophosphate include 2,6,7-trioxa-1-phosphobicyclo (2,2,2) octane-1-oxide, 2,6,7-trioxa-1-phosphobicyclo (2,2 , 2) Octane-4-methyl-1-oxide, 2,6,7-trioxa-1-phosphobicyclo (2,2,2) octane-4-ethyl-1-oxide, 2,6,7-trioxa- 1-phosphobicyclo (2,2,2) octane-4-hexyl-1-oxide, 2,6,7-trioxa-1-phosphobicyclo (2,2,2) octane-4-hexadecyl-1-oxide, etc. 2,6,7-trioxa-1-phosphobicyclo (2,2,2) octane-4-alkyl-1-oxide; 2,6,7-trioxa-1-phosphobicyclo (2,2,2) octane -4-ni Rho-1-oxide, 2,6,7-trioxa-1-phosphobicyclo (2,2,2) octane-4-amino-1-oxide, 2,6,7-trioxa-1-phosphobicyclo (2, 2,2) Octane-4-methanol-1-oxide, 2,8,9-trioxa-1-phosphobicyclo (3,3,1) nonane-5-methyl-1-oxide, 2,6,7-trioxa -1-phosphobicyclo (2,2,1) heptane-4-hexadecyl-1-oxide and the like are included. These bicyclophosphates can be used alone or in combination of two or more. Preferred bicyclophosphates include 2,6,7-trioxa-1-phosphobicyclo (2,2,2) octane-4-methanol-1-oxide and the like.
The amount of the bicyclophosphate used is, for example, 1 to 200 parts by weight, preferably 5 to 100 parts by weight, and more preferably 10 to 80 parts by weight (for example, 20 to 50 parts by weight) with respect to 100 parts by weight of the melamine phosphate. )
[0024]
Examples of the polyhydric alcohol include cyclic or acyclic compounds having a plurality of hydroxyl groups (for example, 3 or 4 or more hydroxyl groups), such as pentaerythritol, dipentaerythritol, tripentaerythritol, and pentitols (adonitol, arabitol). ), Hexitols (such as dulcitol, inositol), and saccharides (such as amylose and xylan) and derivatives thereof (such as N-methylglucamine). These polyhydric alcohols can be used alone or in combination. Preferred polyhydric alcohols include pentaerythritol, dipentaerythritol and the like.
The amount of polyhydric alcohol used is, for example, 1 to 200 parts by weight, preferably 5 to 150 parts by weight, more preferably 10 to 100 parts by weight (for example, 20 to 50 parts by weight) with respect to 100 parts by weight of melamine phosphate. Degree.
[0025]
The flame retardant may further contain silicone oil. Silicone oil includes various polysiloxanes, and may be, for example, free flowing silicone or silicone gum. Examples of the silicone oil include polydialkylsiloxanes such as polydimethylsiloxane, polydiarylsiloxanes such as polydiphenylsiloxane, and polyalkylarylsiloxanes such as polymethylphenylsiloxane. A hydrogen atom, a hydroxyl group, an alkoxy group, an aryl group, a vinyl group, or an allyl group may be bonded to the silicon atom of the silicone oil. These silicone oils can be used alone or in admixture of two or more. Preferred silicone oils include polydimethylsiloxane. The viscosity of the silicone oil (organopolysiloxane) is, for example, about 600 to 300,000,000 centipoise at a temperature of 25 ° C., preferably about 10,000 to 200,000 centipoise, more preferably about 90,000 to 150,000 centipoise. It is.
The amount of silicone oil used is, for example, about 0 to 100 parts by weight, preferably 5 to 80 parts by weight, more preferably 10 to 70 parts by weight (for example, 20 to 50 parts by weight) with respect to 100 parts by weight of melamine phosphate. It is.
In addition, you may use a silicone resin with the said silicone oil or without using a silicone oil as needed.
[0026]
Furthermore, melamine phosphate may be used as a flame retardant by combining it with one of the organic phosphate esters and molybdenum compounds, at least if it is not preferred.
Organophosphate esters (acyclic phosphate flame retardants) include monophosphates, diphosphates and triphosphates, with triphosphates being preferred. Organic phosphate esters include condensed phosphate esters. Organophosphates include triaryl phosphates such as triphenyl phosphate, trixylenyl phosphate, alkylaryl phosphates such as isopropyl triphenyl phosphate, trialkyl phosphates such as tributyl phosphate, and the like. These organophosphates can be used singly or in combination. Preferred organic phosphates include triaryl phosphates (triphenyl phosphate, triphenyl phosphate having about 1 to 4 carbon atoms having a lower alkyl group substituted on the benzene ring).
The amount of the phosphate ester used is, for example, 0 to 200 parts by weight, preferably 5 to 150 parts by weight, more preferably 10 to 100 parts by weight (for example, 20 to 50 parts by weight) with respect to 100 parts by weight of melamine phosphate. Degree.
[0027]
Molybdenum compounds include, for example, oxides such as molybdenum trioxide, sulfides such as molybdenum disulfide, molybdates such as ammonium dimolybdate, calcium molybdate, zinc molybdate, potassium molybdate, and sodium molybdate. included. These compounds can also be used alone or in combination. As the molybdenum compound, an oxide such as molybdenum trioxide is often used. The amount of the molybdenum compound used is, for example, 0 to 50 parts by weight, preferably 0.01 to 25 parts by weight (for example, 0.05 to 20) parts by weight, more preferably 0 to 100 parts by weight of the melamine phosphate. About 1 to 10 parts by weight (for example, 0.5 to 5 parts by weight).
[0028]
The flame retardant may further contain a fluorine-containing resin. Examples of the fluorine-containing resin include polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer, and ethylene-hexafluoropropylene copolymer. The fluorine content of these fluorine-containing resins is 65 to 76% by weight, preferably about 70 to 76% by weight. The density of the fluorine-containing resin is 1.2 to 2.3 g / cm. ³ Often it is a degree.
The fluorine-containing resin is usually used in a granular form, and the particle size of the fluorine-containing resin is, for example, an average particle diameter of 0.05 to 1000 μm, preferably 0.05 to 100 μm, more preferably about 0.08 to 20 μm. is there.
The amount of the fluorine-containing resin used can be selected within a range in which dripping can be suppressed. For example, 0 to 50 parts by weight, preferably 0.01 to 25 parts by weight (for example, 0. 05-20) parts by weight, more preferably about 0.1-10 parts by weight (for example, 0.5-5 parts by weight).
[0029]
Preferred flame retardant combinations include (1) a combination of melamine phosphate and bicyclophosphate ester and / or polyhydric alcohol, (2) a combination of melamine phosphate and bicyclophosphate ester and / or polyhydric alcohol and silicone oil. (3) In addition to the components (1) and (2), a combination in which at least one component selected from a molybdenum compound, a phosphate ester, and a fluorine-containing resin is further added. In the combination (3), at least one of a molybdenum compound and a phosphate ester is often added. Addition of a fluorine-containing resin is effective for preventing dripping accompanying melt softening.
[0030]
The melamine phosphate and the flame retardant of the present invention are useful for making various resins flame retardant. Examples of the resin include polyolefins such as polyethylene and polypropylene, diene polymers such as polybutadiene, vinyl resins such as polyvinyl chloride, acrylic resins such as polymethyl methacrylate, styrene resins, polyethylene terephthalate, and polybutylene terephthalate. Polyesters such as polyester, polyamide 6, polyamide 66, polycarbonate, thermoplastic polyurethane, polyphenylene oxide, polyether, polyacetal, polyphenylene ether, polysulfone, polyethersulfone, polyetherimide, polyamideimide, and other thermoplastic resins, as well as epoxy Resin, vinyl ester resin, phenol resin, amino resin (urea resin, melamine resin, etc.), thermosetting polyurethane, unsaturated Riesuteru include thermosetting resins such as polyimide.
[0031]
The melamine phosphate and the flame retardant of the present invention are preferably useful for flame retarding of thermoplastic resins, particularly styrene resins.
Styrene resins include homopolymers or copolymers of styrene monomers such as styrene, α-methylstyrene, vinyltoluene, styrene monomers and vinyl monomers (such as acrylonitrile and methyl methacrylate ( (Meth) acrylic monomer, maleic anhydride, etc.), rubber component X (for example, diene rubber such as polybutadiene, ethylene / propylene rubber, acrylic rubber, etc.) A graft polymer obtained by graft polymerization of a monomer and a vinyl monomer (such as acrylonitrile) and a styrene block copolymer are included. Examples of the styrene resin include polystyrene, styrene-methyl methacrylate copolymer, styrene-maleic anhydride copolymer, acrylonitrile-styrene copolymer (AS resin), impact-resistant polystyrene, and styrene-based graft polymer. Some AXS resins (ABS resin whose rubber component is polybutadiene, AAS resin whose rubber component is acrylic rubber, AES resin whose rubber component is ethylene-propylene rubber (EPDM), etc.), styrene block copolymer (for example, styrene) -Butadiene-styrene (SBS) copolymer, styrene-isoprene-styrene (SIS) copolymer, styrene-ethylene-butylene-styrene (SEBS) copolymer, and the like. Preferred styrenic resins include polystyrene, acrylonitrile-styrene copolymers, high impact polystyrene, AXS resins such as ABS resin, and styrenic block copolymers. These styrene resins can be used alone or in combination.
[0032]
The melamine phosphate and flame retardant of the present invention can be added in a wide range that can impart flame retardancy to the resin. The addition amount of melamine phosphate is about 1 to 100 parts by weight, preferably 5 to 75 parts by weight, more preferably 10 to 50 parts by weight (for example, 20 to 40 parts by weight) with respect to 100 parts by weight of the resin. When the flame retardant is composed of melamine phosphate and other components, the amount of the flame retardant used is 1 to 150 parts by weight, preferably 5 to 125 parts, based on 100 parts by weight of the resin, depending on the components of the flame retardant. It is about 10 to 100 parts by weight (for example, 20 to 70 parts by weight).
[0033]
The resin composition containing melamine phosphate and the flame retardant can be prepared by dry-wetting or wet-mixing or melt-kneading the resin and melamine phosphate or the flame retardant. In the resin composition, conventional additives, for example, stabilizers such as antioxidants, ultraviolet absorbers, light stabilizers, plasticizers, antistatic agents, lubricants, fillers, impact modifiers, fillers, A reinforcing agent, a colorant, a hue improver, and the like may be added. The resin composition is useful for producing a molded product by various molding methods such as extrusion molding and injection molding.
[0034]
【The invention's effect】
The melamine phosphate of the present invention exhibits specific endothermic characteristics and X-ray diffraction spectra in differential thermal analysis, and can impart high flame retardancy to various resins such as styrene resins. In addition, since it is a non-halogen compound, melamine phosphate not only generates corrosive and toxic gases, but also has high flame retardancy. Therefore, flame retardance can be increased by adding a relatively small amount.
[0035]
【Example】
Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.
Example 1
A jacketed reactor equipped with a stirrer, a reflux condenser, and a thermometer was charged with 100 g (0.79 mol) of melamine and 3500 g of water, and then heated to 90 ° C. with stirring. Subsequently, 91.5 g (0.79 mol) of 85 wt% orthophosphoric acid aqueous solution was added dropwise over 30 minutes and reacted at 90 ° C. for 1 hour. The reaction mixture was cooled to 25 ° C., and a thriller-like reaction mixture was taken out and filtered to obtain white crystals. The crystals were washed with 200 g of water and filtered to obtain 195 g of white melamine phosphate crystals. This wet crystal was dried at 180 ° C. for 2 hours with a hot air dryer to obtain 140 g of melamine phosphate.
FIG. 1 shows a differential thermal analysis curve of the obtained melamine phosphate, and FIG. 6 shows an X-ray diffraction spectrum.
[0036]
Example 2
A jacketed reactor equipped with a stirrer, a reflux condenser, and a thermometer was charged with 100 g (0.79 mol) of melamine and 3500 g of water, and then heated to 95 ° C. with stirring. Subsequently, 91.5 g (0.79 mol) of 85 wt% orthophosphoric acid aqueous solution was dropped over 15 minutes, and the mixture was reacted for 1 hour under reflux. The reaction mixture was cooled to 25 ° C., and a thriller-like reaction mixture was taken out and filtered to obtain white crystals. The crystals were washed with 200 g of water and filtered to obtain 198 g of white melamine phosphate wet crystals. The wet crystals were dried at 200 ° C. for 1 hour with a hot air dryer to obtain 138 g of melamine phosphate.
Example 3
The melamine phosphate 195 g obtained under the same reaction conditions and post-treatment as in Example 2 was dried for 10 hours at a jacket temperature of 90 ° C. and 1 torr using a stirring-type vacuum dryer to obtain melamine phosphate. 137 g was obtained. FIG. 2 shows a differential thermal analysis curve of the obtained melamine phosphate, and FIG. 7 shows an X-ray diffraction spectrum.
[0037]
Example 4
A jacketed reactor equipped with a stirrer, a reflux condenser, and a thermometer was charged with 100 g (0.79 mol) of melamine and 3000 g of water, and then heated to 95 ° C. with stirring. Next, 82.4 g (0.71 mol) of an 85 wt% orthophosphoric acid aqueous solution was added dropwise over 15 minutes, and the mixture was reacted for 15 minutes under reflux. The reaction mixture was cooled to 25 ° C., and a thriller-like reaction mixture was taken out and filtered to obtain 200 g of white melamine phosphate wet crystals. This wet crystal was dried at 150 ° C. for 2 hours with a hot air dryer to obtain 141 g of melamine phosphate.
[0038]
Example 5
A jacketed reactor equipped with a stirrer, a reflux condenser, and a thermometer was charged with 100 g (0.79 mol) of melamine and 2000 g of water, and then heated to 95 ° C. with stirring. Subsequently, 73.2 g (0.63 mol) of 85 wt% orthophosphoric acid aqueous solution was added dropwise over 15 minutes, and the reaction was allowed to proceed for 15 minutes under reflux. The reaction mixture was cooled to 25 ° C., and a thriller-like reaction mixture was taken out and filtered to obtain 192 g of white wet crystals of melamine phosphate. The wet crystals were dried with a hot air dryer at 150 ° C. for 2 hours to obtain 135 g of melamine phosphate.
[0039]
Comparative Example 1
A jacketed reactor equipped with a stirrer, a reflux condenser, and a thermometer was charged with 100 g (0.79 mol) of melamine and 3500 g of water, and then heated to 90 ° C. Subsequently, 101 g (0.88 mol) of an 85 wt% orthophosphoric acid aqueous solution was added dropwise over 30 minutes and reacted at 90 ° C. for 1 hour. The reaction mixture was cooled to 25 ° C., and a thriller-like reaction mixture was taken out and filtered to obtain white crystals. The crystals were washed with 200 g of water and filtered to obtain 223 g of white melamine phosphate crystals. This wet crystal was dried at 180 ° C. for 2 hours to obtain 153 g of melamine phosphate. FIG. 3 shows a differential thermal analysis curve of melamine phosphate, and FIG. 8 shows an X-ray diffraction spectrum.
[0040]
Comparative Example 2
A jacketed reactor equipped with a stirrer, a reflux condenser, and a thermometer was charged with 100 g (0.79 mol) of melamine and 3500 g of water, and then heated to 90 ° C. Subsequently, 137 g (1.19 mol) of 85 wt% orthophosphoric acid aqueous solution was added dropwise over 30 minutes, and reacted at 90 ° C. for 1 hour. The reaction mixture was cooled to 25 ° C., and a thriller-like reaction mixture was taken out and filtered to obtain white crystals. The crystals were washed with 200 g of water and filtered to obtain 203 g of white melamine phosphate wet crystals. This wet crystal was dried at 180 ° C. for 2 hours to obtain 155 g of melamine phosphate. FIG. 4 shows a differential thermal analysis curve of melamine phosphate, and FIG. 9 shows an X-ray diffraction spectrum.
[0041]
Comparative Example 3
A commercially available melamine phosphate (manufactured by Sanwa Chemical Co., Ltd., trade name MPP-A) was used. FIG. 5 shows a differential thermal analysis curve of melamine phosphate, and FIG. 10 shows an X-ray diffraction spectrum.
[0042]
[Thermal analysis and X-ray diffraction]
And the differential thermal analysis of the melamine phosphate obtained by the said Example and the comparative example was 10 degreeC / from room temperature to 500 degreeC using the thermogravimetric-differential-heat measuring apparatus (Rigaku Co., Ltd. product, Thermoflex 8110). Min. Table 1 shows the observation positions (temperature ° C) of three main peaks among the observed endothermic peaks.
The X-ray diffraction spectrum of the melamine phosphate was measured using an X-ray diffraction apparatus (RINT-1500, manufactured by Rigaku Corporation). Table 1 shows diffraction angles 2θ (°) of the top three main peaks in order from the peak showing the maximum intensity among the observed diffraction peaks.
[0043]
[Flame retardance]
Furthermore, the evaluation as a flame retardant of the said melamine phosphate was performed in the following way. That is, high impact polystyrene (HIPS, polybutadiene content 9% by weight, polystyrene weight average molecular weight 23 × 10 ⁴ ) 30 parts by weight of the melamine phosphate, 10 parts by weight of dipentaerythritol and 2,6,7-trioxa-1-phosphobicyclo (2,2,2) octane-4-methanol-1-oxide 10 After adding a weight part and mixing with a tumbler blender, it melt-kneaded with the extruder and obtained the pellet-shaped resin composition. Using an injection molding machine (cylinder temperature 200 ° C., mold temperature 50 ° C.), a test piece for general physical properties was prepared from the obtained pellet-shaped resin composition, and the characteristics of the test piece were measured as follows. The results are shown in Table 1.
[0044]
(1) Flame resistance
In accordance with the vertical flammability test (94V-0) defined in the US UL standard, the flame retardance of a 1/8 inch thick test piece was evaluated.
(2) Impact strength
The Izod impact strength without a notch was evaluated about the 1 / 4-inch-thick test piece.
[0045]
[Table 1]

As is apparent from Table 1, when the melamine phosphate obtained in the examples is used, flame resistance can be remarkably improved without adversely affecting impact resistance and the like, and high flame retardancy can be imparted to the resin.
[Brief description of the drawings]
1 is a diagram showing a differential thermal analysis curve of melamine phosphate obtained in Example 1. FIG.
2 is a diagram showing a differential thermal analysis curve of melamine phosphate obtained in Example 3. FIG.
3 is a diagram showing a differential thermal analysis curve of melamine phosphate obtained in Comparative Example 1. FIG.
4 is a diagram showing a differential thermal analysis curve of melamine phosphate obtained in Comparative Example 2. FIG.
5 is a diagram showing a differential thermal analysis curve of melamine phosphate of Comparative Example 3. FIG.
6 is a diagram showing an X-ray diffraction spectrum of melamine phosphate of Example 1. FIG.
7 is a view showing an X-ray diffraction spectrum of melamine phosphate of Example 3. FIG.
8 is a view showing an X-ray diffraction spectrum of melamine phosphate of Comparative Example 1. FIG.
9 is a view showing an X-ray diffraction spectrum of melamine phosphate of Comparative Example 2. FIG.
10 is a diagram showing an X-ray diffraction spectrum of melamine phosphate of Comparative Example 3. FIG.

Claims (13)

It is a reaction product of melamine and phosphoric acid, and when measured by differential thermal analysis at a heating rate of 10 ° C./min, endothermic regions are observed at 290 ± 10 ° C., 320 ± 10 ° C. and 390 ± 10 ° C. Melamine phosphate. The endothermic peak height in the endothermic region of 290 ± 10 ° C is Ph1, the endothermic peak height in the endothermic region of 320 ± 10 ° C is Ph2, and the endothermic peak height in the endothermic region of 390 ± 10 ° C is 2. The melamine phosphate according to claim 1, wherein the endothermic peak is large in the order of Ph 1 <Ph 2 <Ph 3 when Ph 3 is set. The melamine phosphate according to claim 1, wherein a sharp endothermic peak is shown in the temperature range of 320 ± 10 ° C and 390 ± 10 ° C, and a sharp or broad endothermic region is shown in the temperature range of 290 ± 10 ° C. A reaction product of melamine and phosphoric acid, wherein the diffraction angle 2θ is 17.5 ± 0.5 °, 19.3 ± 0.5 °, and 24.9 ± 0.5 in the X-ray diffraction spectrum. Melamine phosphate with a peak observed in the region of °. The peak height of diffraction angle 2θ = 17.5 ± 0.5 ° is Px1, 2θ = 19.3 ± 0.5 ° peak height is Px2, 2θ = 24.9 ± 0.5 °. The melamine phosphate according to claim 4, wherein when the peak height is Px3, the intensity in the diffraction spectrum is smaller in the order of Px1> Px3> Px2. The peak Px1 at 2θ = 17.5 ± 0.5 ° shows the maximum intensity in the diffraction spectrum, and the peak Px3 at 2θ = 24.9 ± 0.5 ° is the second or third position in the diffraction spectrum. The melamine phosphate according to claim 4, which has an X-ray diffraction pattern showing the intensity of the following. The atomic ratio (N / P) of nitrogen (N) and phosphorus (P) is 6.2 to 7.8. Melamine phosphate according to any one of claims 1 to 6. Melamine phosphate, a reaction product of melamine and phosphoric acid, having the following characteristics:
(1) Endothermic regions are observed at 290 ± 10 ° C., 320 ± 10 ° C., and 390 ± 10 ° C. when measured at 10 ° C./min by differential thermal analysis (2) X-ray diffraction spectrum , Peaks are observed in the regions of diffraction angles 2θ = 17.5 ± 0.5 °, 2θ = 19.3 ± 0.5 ° and 2θ = 24.9 ± 0.5 ° (3) Nitrogen The atomic ratio (N / P) of (N) to phosphorus (P) is 6.2 to 7.8. A flame retardant comprising the melamine phosphate according to claim 1, 4 or 8. The flame retardant according to claim 9, further comprising at least one component of a bicyclophosphate ester and a polyhydric alcohol. Furthermore, the flame retardant of Claim 9 or 10 containing a silicone oil. The flame retardant according to any one of claims 9 to 11, further comprising at least one component of a molybdenum compound and a phosphate ester. The flame retardant according to any one of claims 9 to 12, further comprising a fluorine-containing resin.

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