JPH0380805B2 - - Google Patents
Info
- Publication number
- JPH0380805B2 JPH0380805B2 JP60109054A JP10905485A JPH0380805B2 JP H0380805 B2 JPH0380805 B2 JP H0380805B2 JP 60109054 A JP60109054 A JP 60109054A JP 10905485 A JP10905485 A JP 10905485A JP H0380805 B2 JPH0380805 B2 JP H0380805B2
- Authority
- JP
- Japan
- Prior art keywords
- polymerization
- monomer
- methacrylic acid
- added
- styrene
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000000178 monomer Substances 0.000 claims description 50
- 238000006116 polymerization reaction Methods 0.000 claims description 46
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical group C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 claims description 27
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 claims description 18
- 238000010557 suspension polymerization reaction Methods 0.000 claims description 12
- 239000012736 aqueous medium Substances 0.000 claims description 9
- 238000004519 manufacturing process Methods 0.000 claims description 8
- 229920006249 styrenic copolymer Polymers 0.000 claims description 7
- JLBJTVDPSNHSKJ-UHFFFAOYSA-N 4-Methylstyrene Chemical compound CC1=CC=C(C=C)C=C1 JLBJTVDPSNHSKJ-UHFFFAOYSA-N 0.000 claims description 4
- 125000003011 styrenyl group Chemical group [H]\C(*)=C(/[H])C1=C([H])C([H])=C([H])C([H])=C1[H] 0.000 claims 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 21
- 229920001577 copolymer Polymers 0.000 description 14
- 229920003145 methacrylic acid copolymer Polymers 0.000 description 10
- 239000000203 mixture Substances 0.000 description 9
- JQXYBDVZAUEPDL-UHFFFAOYSA-N 2-methylidene-5-phenylpent-4-enoic acid Chemical compound OC(=O)C(=C)CC=CC1=CC=CC=C1 JQXYBDVZAUEPDL-UHFFFAOYSA-N 0.000 description 8
- 229920000642 polymer Polymers 0.000 description 6
- 239000004372 Polyvinyl alcohol Substances 0.000 description 5
- 229940117841 methacrylic acid copolymer Drugs 0.000 description 5
- 229920002451 polyvinyl alcohol Polymers 0.000 description 5
- 239000004342 Benzoyl peroxide Substances 0.000 description 4
- OMPJBNCRMGITSC-UHFFFAOYSA-N Benzoylperoxide Chemical compound C=1C=CC=CC=1C(=O)OOC(=O)C1=CC=CC=C1 OMPJBNCRMGITSC-UHFFFAOYSA-N 0.000 description 4
- 235000019400 benzoyl peroxide Nutrition 0.000 description 4
- 239000002270 dispersing agent Substances 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 3
- QIGBRXMKCJKVMJ-UHFFFAOYSA-N Hydroquinone Chemical compound OC1=CC=C(O)C=C1 QIGBRXMKCJKVMJ-UHFFFAOYSA-N 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000007334 copolymerization reaction Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000004945 emulsification Methods 0.000 description 2
- 150000002148 esters Chemical class 0.000 description 2
- 239000003112 inhibitor Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 239000003505 polymerization initiator Substances 0.000 description 2
- LPXPTNMVRIOKMN-UHFFFAOYSA-M sodium nitrite Chemical compound [Na+].[O-]N=O LPXPTNMVRIOKMN-UHFFFAOYSA-M 0.000 description 2
- GJBRNHKUVLOCEB-UHFFFAOYSA-N tert-butyl benzenecarboperoxoate Chemical compound CC(C)(C)OOC(=O)C1=CC=CC=C1 GJBRNHKUVLOCEB-UHFFFAOYSA-N 0.000 description 2
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 1
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 1
- IMROMDMJAWUWLK-UHFFFAOYSA-N Ethenol Chemical compound OC=C IMROMDMJAWUWLK-UHFFFAOYSA-N 0.000 description 1
- PIICEJLVQHRZGT-UHFFFAOYSA-N Ethylenediamine Chemical class NCCN PIICEJLVQHRZGT-UHFFFAOYSA-N 0.000 description 1
- 229920000663 Hydroxyethyl cellulose Polymers 0.000 description 1
- 239000004354 Hydroxyethyl cellulose Substances 0.000 description 1
- YIVJZNGAASQVEM-UHFFFAOYSA-N Lauroyl peroxide Chemical compound CCCCCCCCCCCC(=O)OOC(=O)CCCCCCCCCCC YIVJZNGAASQVEM-UHFFFAOYSA-N 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- XYLMUPLGERFSHI-UHFFFAOYSA-N alpha-Methylstyrene Chemical compound CC(=C)C1=CC=CC=C1 XYLMUPLGERFSHI-UHFFFAOYSA-N 0.000 description 1
- UPIWXMRIPODGLE-UHFFFAOYSA-N butyl benzenecarboperoxoate Chemical group CCCCOOC(=O)C1=CC=CC=C1 UPIWXMRIPODGLE-UHFFFAOYSA-N 0.000 description 1
- 239000001768 carboxy methyl cellulose Substances 0.000 description 1
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 1
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- OPQARKPSCNTWTJ-UHFFFAOYSA-L copper(ii) acetate Chemical compound [Cu+2].CC([O-])=O.CC([O-])=O OPQARKPSCNTWTJ-UHFFFAOYSA-L 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 235000014113 dietary fatty acids Nutrition 0.000 description 1
- 239000003995 emulsifying agent Substances 0.000 description 1
- 238000007720 emulsion polymerization reaction Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000000194 fatty acid Substances 0.000 description 1
- 229930195729 fatty acid Natural products 0.000 description 1
- 150000004665 fatty acids Chemical class 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 235000019447 hydroxyethyl cellulose Nutrition 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000003999 initiator Substances 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 229940057995 liquid paraffin Drugs 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 230000000873 masking effect Effects 0.000 description 1
- 239000002609 medium Substances 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 229920000609 methyl cellulose Polymers 0.000 description 1
- 239000001923 methylcellulose Substances 0.000 description 1
- 235000010981 methylcellulose Nutrition 0.000 description 1
- 239000012778 molding material Substances 0.000 description 1
- 150000001451 organic peroxides Chemical class 0.000 description 1
- 229920000620 organic polymer Polymers 0.000 description 1
- 229920001083 polybutene Polymers 0.000 description 1
- 230000000379 polymerizing effect Effects 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 235000019422 polyvinyl alcohol Nutrition 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 235000010288 sodium nitrite Nutrition 0.000 description 1
- 150000003440 styrenes Chemical class 0.000 description 1
- 238000010558 suspension polymerization method Methods 0.000 description 1
Description
(イ) 産業上の利用分野
本発明はスチレン系共重合体の製造方法に関す
る。さらに詳しくは、懸濁重合方法によつて耐熱
性、透明性の秀れたスチレン―メタクリル酸共重
合体やパラメチルスチレン−メタクリル酸共重合
体等のスチレン系共重合体を得る製造方法に関す
る。
(ロ) 従来の技術
スチレンとメタクリル酸との共重合体を得る方
法として、従来から種々の手法が提案されてお
り、比較的透明なスチレン−メタクリル酸共重合
体が懸濁重合法によつて作成可能であることは特
開昭58−96641号公報に開示されているように公
知である。
(ハ) 発明が解決しようとする問題点
しかしながら、従来の懸濁重合条件によつて得
られたスチレン―メタクリル酸共重合体の透明性
は依然充分なものではなく、ことに、本発明者の
実験によれば、前記公報にあるように、ただ単に
使用されるモノマーと水の割合が１：２の条件下
でメタクリル酸単量体を重合開始時に加えて開始
剤の存在下に重合したのでは耐熱性のすぐれた透
明性のよいスチレン−メタクリル酸共重合体を得
ることが出来ないということが確認されている。
この点に関し、先に本発明者は、スチレンやパ
ラメチルスチレンのごときスチレン系単量体とメ
タクリル酸との共重合体の懸濁重合においては、
メタクリル酸が水と単量体双方に自由に溶解する
ため、モノマーと水の使用する割合が共重合組成
に重要な影響を及ぼしているとの観点に立ち研究
を行なつた。そしてその結果、まずメタクリル酸
を重合開始時に全量加えて重合する場合には使用
される全単量体と水の割合を１：３から１：７の
範囲に調整して懸濁重合することにより耐熱性と
透明性に秀れたスチレン−メタクリル酸共重合が
得られる事実を見出した。
しかし上記方法では単量体に対する水の使用量
が多い（１：３〜１：７）ので生産性が低下する
という実用的な問題がのこる。
本発明はかかる状況に鑑みなされたものであ
り、生産性を低下させることなく優れた耐熱性及
び透明性を備えたスチレン系共重合体を得る方法
を提供しようとするものである。
本発明者は、さらに鋭意研究した結果、使用す
る単量体と水の割合が１：0.8〜１：３の範囲で
使用するメタクリル酸全量の30〜80％を重合開始
時に加え残りの70〜20％を重合中に後添加して懸
濁重合することにより耐熱性のすぐれた、透明性
のよいスチレン−メタクリル酸共重合体やパラメ
チルスチレン−メタクリル酸共重合体を製造しう
る事実を見出し本発明に到達した。
(ハ) 問題点を解決するための手段及び作用
かくして本発明によればスチレン系単量体とメ
タクリル酸単量体とを水媒体中に添加し懸濁重合
条件に付してスチレン系共重合体を製造する方法
において、
添加する単量体の合計量と水媒体との割合が
１：0.8〜１：３（重量比）の範囲内でスチレン系
単量体とメタクリル酸単量体との添加比率を前
者：後者として95〜75重量％：５〜25重量％に設
定すると共に、添加するメタクリル酸単量体全量
の約30〜80％を実質的に全量のスチレン系単量体
と共に水媒体中に存在させて重合反応を開始し、
残りの約70〜20％を重合の進行に対応して断続的
又は連続的に後添加して共重合させることを特徴
とするスチレン系共重合体の製造方法が提供され
る。
この発明の最も特徴とする点は、使用する全単
量体と水の割合が１：３よりも水が少ない系で懸
濁重合する場合において、使用するメタクリル酸
（以下MAAと記す）単量体の全量を加えてから
重合を開始するのではなくて重合開始時と重合中
とに分割して加えた点にある。
本発明者の認識によれば、MAA単量体を重合
開始時に全量加えて懸濁重合するとき、使用する
水の割合が多い場合にはMAA単量体の水系に分
配する量が多くなり、スチレン系単量体相への分
配はその分少なくなつて重合率の低い時点で生成
する共重合体中のMAA含有量が全仕込組成に近
い値を示す。しかし、上記のごとき水の割合が少
ない場合にはスチレン系単量体相のMAA単量体
も多くなり重合初期の低重合率のときには仕込組
成よりも非常に高いMAA含有量の共重合体が生
成し重合後期の重合率の高い時点ではMAA含有
量の低い共重合体が生成するので不均一組成の共
重合体しか得られない。このような共重合体は耐
熱性も透明性も不満足なものである。すなわち、
重合開始時にMAA単量体の全量を加えて重合を
開始するのでは使用する全単量体に対する水の使
用する割合が少ない場合には比較的均一な共重合
体を得ることは出来ない。しかしながら、本発明
においては、前記のごとく、MAA単量体の添加
を重合開始時と重合進行中に特定比で分割して行
なうため、水使用割合が少ないにもかかわらず初
期におけるMAA単量体のスチレン系単量体中へ
の過度の分配が防止され、かつ重合の進行と共に
減少するMAA単量体が実質的に補充された状態
でスチレン系単量体とMAA単量体との共重合が
行なわれ、均一な組成で耐熱性及び透明性の優れ
たスチレン系共重合体を得ることが可能となる。
本発明において重合開始時に添加しておく
MAA単量体の量は、重合初期に生成する共重合
体の組成と最終の仕込組成がほぼ一致するよう調
整しておくのが適しており、具体的には添加を意
図するMAA単量体全量の約30〜80％を水媒体中
に存在させて重合を開始する。そして残りの約70
〜20％の後添加は、重合の進行にともない重合系
内で消費されるMAA単量体の量に見合うように
MAA単量体を断続もしくは連続的に添加するの
が適している。
重合開始時に加えるMAA単量体の量がMAA
単量体全量の30％よりも少ないと重合初期に生成
する共重合体中のMAA含有量が最終仕込組成よ
りも大巾に少ないものとなる。又80％よりも多い
と逆にMAA含有量の多すぎるものが生成する。
いずれもMAA含有量のいちじるしく不均一な共
重合体になり耐熱性、透明性が損なわれる。
一方のスチレン系単量体は通常、重合開始時に
水媒体中に全量添加されるが、場合によつてはそ
の一部ことに少量を後添加することも可能であ
り、重合開始時に実質的に全量、水媒体中に存在
しておればよい。例えば、少量のスチレン系単量
体の後添加としては、MAA単量体は融点が約16
℃にあるため冬期凍結の問題があるので後添加す
るMAA単量体１部に対し0.2〜１部のスチレン系
単量体を加えた溶液を添加する例が挙げられる。
この発明に用いるスチレン系単量体としてはス
チレン、低級アルキル基置換スチレン等が挙げら
れるが、通常、スチレン又はメチルスチレンを用
いるのが好ましい。一方、スチレン系単量体全量
とMAA単量体全量の使用比率は、前者：後者と
して95〜75重量％：５〜25重量％とされる。
MAA単量体５重量％以下では耐熱性向上のメリ
ツトが小さく、25重量％以上では機械的物性の低
下が大きいので好ましくない。なお、場合によつ
ては上記懸濁重合系中に他の重合可能な単量体を
存在させてもよく、例えば、アクリル酸及びメタ
クリル酸のエステル、α−メチルスチレン、アク
リロニトリルなどを加えてそれぞれの目的に合つ
た特徴をもたせることも出来る。
本発明における懸濁重合に使用される分散剤は
保護コロイド性を有する水溶性有機高分子化合物
が好ましい。例えば部分鹸化ポリビニルアルコー
ル、ヒドロキシエチルセルロース、メチルセルロ
ース、カルボキシメチルセルロースなどでその使
用量は水に対して0.03〜0.5重量％が適している。
又乳化重合を防止するのに亜硝酸ソーダ、酢酸
銅、エチレンジアミン化合物、ハイドロキノンな
どの水溶性重合禁止剤を水に対して0.0005〜0.3
重量％加えることが必要である。
重合開始剤としてはベンゾイルパーオキサイ
ド、ラウロイルパーオキサイド、１，１−ビスタ
ーシヤリーブチルーパーオキシ−３，３，５−ト
リメチルシクロヘキサン、ジターシヤリーブチル
ーパーオキシヘキサハイドロテレフタレートなど
の有機過酸化物が使用される。
懸濁重合の温度は使用される重合開始剤の分解
温度に応じた温度に設定する。通常は70〜95℃の
範囲で重合率70−95％まで反応したのち120〜140
℃に昇温して重合を完結させるのが望ましい。
又通常のポリスチレンの場合のように流動パラ
フイン、ポリブデン、高級脂肪酸、及びそのエス
テルなどの滑剤、あるいはマスキング剤を重合開
始前に単量体に溶解して重合を開始することも出
来る。
このようにして得られた本発明の共重合体は粒
状であり、これを用いて種々の成形用素材や成形
品を作成することができる。
(ヘ) 実施例
実施例 １
５の反応器に水2000ｇ、分散剤としてPVA
（ポリビニルアルコール；日本合成化学工業kkゴ
ーセノールGM−14L）３ｇを加え、80℃に昇温
して撹拌溶解したのち、乳化防止剤として
EDTA0.4ｇを加えた。次にスチレン850ｇにベン
ゾイルパーオキサイド2.5ｇ、ターシヤリーブチ
ルーパーオキシベンゾエート１ｇを溶解して加え
た。メタクリル酸150ｇは第１表に示すように重
合開始時と重合中とに分割して加えた。次いで85
℃で６時間重合したのち125℃まで昇温して２時
間保持して反応を完了した。重合中及び得られ重
合体のデーターを表１に示す。
(a) Industrial Application Field The present invention relates to a method for producing a styrenic copolymer. More specifically, the present invention relates to a method for producing styrene copolymers such as styrene-methacrylic acid copolymers and para-methylstyrene-methacrylic acid copolymers having excellent heat resistance and transparency by a suspension polymerization method. (b) Prior art Various methods have been proposed to obtain copolymers of styrene and methacrylic acid, and relatively transparent styrene-methacrylic acid copolymers have been produced by suspension polymerization. It is known that it can be produced as disclosed in Japanese Patent Application Laid-Open No. 58-96641. (c) Problems to be Solved by the Invention However, the transparency of the styrene-methacrylic acid copolymer obtained by conventional suspension polymerization conditions is still not sufficient, and in particular, the present inventor's problem According to experiments, as stated in the above publication, methacrylic acid monomer was simply added at the start of polymerization under conditions where the ratio of monomer to water used was 1:2, and polymerization was carried out in the presence of an initiator. It has been confirmed that it is not possible to obtain a styrene-methacrylic acid copolymer with excellent heat resistance and good transparency. Regarding this point, the present inventor previously found that in suspension polymerization of a copolymer of a styrene monomer such as styrene or paramethylstyrene and methacrylic acid,
Since methacrylic acid is freely soluble in both water and monomers, the research was conducted from the viewpoint that the ratio of monomers and water used has an important influence on the copolymer composition. As a result, when polymerizing by adding the entire amount of methacrylic acid at the beginning of polymerization, it is possible to adjust the ratio of the total monomers and water used in the range of 1:3 to 1:7 and carry out suspension polymerization. We have discovered that a styrene-methacrylic acid copolymer with excellent heat resistance and transparency can be obtained. However, in the above method, the amount of water used relative to the monomer is large (1:3 to 1:7), so a practical problem remains that productivity is reduced. The present invention was made in view of this situation, and it is an object of the present invention to provide a method for obtaining a styrenic copolymer having excellent heat resistance and transparency without reducing productivity. As a result of further intensive research, the present inventor discovered that by adding 30 to 80% of the total amount of methacrylic acid to be used at the start of polymerization, the ratio of monomer to water used was in the range of 1:0.8 to 1:3. Discovered the fact that it is possible to produce styrene-methacrylic acid copolymers and para-methylstyrene-methacrylic acid copolymers with excellent heat resistance and transparency by post-adding 20% during polymerization and carrying out suspension polymerization. We have arrived at the present invention. (c) Means and effects for solving the problems Thus, according to the present invention, a styrenic monomer and a methacrylic acid monomer are added to an aqueous medium and subjected to suspension polymerization conditions to form a styrenic copolymer. In the method for producing a styrene monomer and a methacrylic acid monomer, the ratio of the total amount of monomers to be added to the aqueous medium is within the range of 1:0.8 to 1:3 (weight ratio). The addition ratio is set to 95 to 75% by weight: 5 to 25% by weight as the former: the latter, and about 30 to 80% of the total amount of methacrylic acid monomer to be added is added to water along with substantially the entire amount of styrene monomer. present in the medium to initiate the polymerization reaction,
There is provided a method for producing a styrenic copolymer, characterized in that the remaining approximately 70 to 20% is post-added intermittently or continuously in accordance with the progress of polymerization for copolymerization. The most distinctive feature of this invention is that when suspension polymerization is carried out in a system where the ratio of all monomers to water used is less than 1:3, the amount of methacrylic acid (hereinafter referred to as MAA) monomer used is Rather than starting the polymerization after adding the entire amount of the polymer, the polymer was added in portions at the beginning and during the polymerization. According to the present inventor's understanding, when the entire amount of MAA monomer is added at the start of polymerization and suspension polymerization is carried out, if a large proportion of water is used, the amount of MAA monomer distributed to the aqueous system increases; The distribution to the styrenic monomer phase decreases accordingly, and the MAA content in the copolymer produced at a low polymerization rate shows a value close to the total feed composition. However, when the proportion of water is small as described above, the amount of MAA monomer in the styrene monomer phase increases, and at a low polymerization rate in the early stage of polymerization, a copolymer with a much higher MAA content than the starting composition is produced. When the polymerization rate is high in the late stage of polymerization, a copolymer with a low MAA content is produced, so only a copolymer with a heterogeneous composition can be obtained. Such copolymers have unsatisfactory heat resistance and transparency. That is,
If the entire amount of MAA monomer is added at the start of polymerization to initiate polymerization, a relatively uniform copolymer cannot be obtained if the proportion of water to the total monomers used is small. However, in the present invention, as mentioned above, since the MAA monomer is added at a specific ratio at the beginning of polymerization and during the progress of polymerization, the MAA monomer is added at the initial stage even though the proportion of water used is small. Copolymerization of styrenic monomers and MAA monomers in a state in which excessive distribution of styrenic monomers into the styrenic monomers is prevented and MAA monomers, which decrease as the polymerization progresses, are substantially replenished. This makes it possible to obtain a styrenic copolymer with a uniform composition and excellent heat resistance and transparency. In the present invention, it is added at the start of polymerization.
It is appropriate to adjust the amount of MAA monomer so that the composition of the copolymer produced at the initial stage of polymerization and the final charged composition almost match. About 30-80% of the total amount is present in the aqueous medium to initiate the polymerization. and the remaining approximately 70
~20% post-addition to match the amount of MAA monomer consumed within the polymerization system as the polymerization progresses.
It is suitable to add MAA monomer intermittently or continuously. The amount of MAA monomer added at the start of polymerization is MAA
If it is less than 30% of the total amount of monomers, the MAA content in the copolymer produced at the initial stage of polymerization will be significantly lower than the final composition. On the other hand, if the amount is more than 80%, products containing too much MAA will be produced.
In either case, the MAA content becomes a significantly non-uniform copolymer, resulting in loss of heat resistance and transparency. On the other hand, the styrenic monomer is usually added in its entirety to the aqueous medium at the start of polymerization, but in some cases it is also possible to add a small amount to a portion of the aqueous medium, so that it is substantially It is sufficient that the entire amount is present in the aqueous medium. For example, as a post-addition of small amounts of styrenic monomer, MAA monomer has a melting point of about 16
℃, there is a problem of freezing in winter, so an example is to add a solution containing 0.2 to 1 part of styrene monomer to 1 part of MAA monomer that is added later. Examples of the styrene monomer used in this invention include styrene and lower alkyl group-substituted styrene, but it is usually preferable to use styrene or methylstyrene. On the other hand, the usage ratio of the total amount of styrene monomers and the total amount of MAA monomers is 95 to 75% by weight: 5 to 25% by weight as the former:the latter.
If the MAA monomer content is less than 5% by weight, the benefit of improving heat resistance will be small, and if it is more than 25% by weight, the mechanical properties will deteriorate significantly, which is not preferable. In some cases, other polymerizable monomers may be present in the suspension polymerization system. For example, esters of acrylic acid and methacrylic acid, α-methylstyrene, acrylonitrile, etc. may be added to each. It is also possible to add features that suit the purpose. The dispersant used in suspension polymerization in the present invention is preferably a water-soluble organic polymer compound having protective colloidal properties. For example, partially saponified polyvinyl alcohol, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, etc., are suitably used in an amount of 0.03 to 0.5% by weight based on water.
Also, to prevent emulsion polymerization, add water-soluble polymerization inhibitors such as sodium nitrite, copper acetate, ethylenediamine compounds, and hydroquinone to 0.0005 to 0.3 of water.
It is necessary to add % by weight. As a polymerization initiator, organic peroxides such as benzoyl peroxide, lauroyl peroxide, 1,1-bistershaributylperoxy-3,3,5-trimethylcyclohexane, and ditertiarybutylperoxyhexahydroterephthalate are used. be done. The temperature of suspension polymerization is set to a temperature corresponding to the decomposition temperature of the polymerization initiator used. Usually, after reacting in the range of 70 to 95℃ to a polymerization rate of 70 to 95%,
It is desirable to complete the polymerization by raising the temperature to .degree. Furthermore, as in the case of ordinary polystyrene, polymerization can be initiated by dissolving a lubricant such as liquid paraffin, polybutene, higher fatty acids, and their esters, or a masking agent in the monomers before the initiation of polymerization. The thus obtained copolymer of the present invention is in the form of particles, and can be used to create various molding materials and molded articles. (f) Examples Example 1 2000g of water in the 5 reactor, PVA as a dispersant
(Polyvinyl alcohol; Nippon Gosei Kagaku Kogyo KK Gohsenol GM-14L) was added, heated to 80°C, stirred and dissolved, and then used as an anti-emulsifying agent.
0.4 g of EDTA was added. Next, 2.5 g of benzoyl peroxide and 1 g of tert-butyl peroxybenzoate were dissolved and added to 850 g of styrene. 150 g of methacrylic acid was added in portions at the beginning of polymerization and during polymerization as shown in Table 1. then 85
After polymerization at 125°C for 6 hours, the temperature was raised to 125°C and maintained for 2 hours to complete the reaction. Table 1 shows the data during polymerization and the obtained polymer.
【表】【table】
【表】
このデーターはモノマーと水の割合が１：２の
場合についてである。重合開始時に加えるMAA
量は使用されるMAA全量の約30−80％くらいが
好ましいことを示している。この範囲以外は重合
過程における生成ポリマー中のMAA含有量の変
化が大きく得られるポリマーが不均一になり耐熱
性が低下し透明性も損われることがわかる。
実施例 ２
この実施例はモノマーと水の割合が１：１の場
合について示す。５の反応器に水2000ｇ、分散
剤としてPVA6ｇを加え、80℃に昇温して撹拌溶
解したのち、乳化防止剤としてEDTA0.6ｇを加
えた。次にスチレン1700ｇにベンゾイルパーオキ
サイド５ｇとターシヤリーブチルーパーオキシベ
ンゾエート２ｇを溶解して加えた。メタクリル酸
300ｇは第２表に示すように分割して加える場合
と分割しない場合の比較をおこなつた。次いで85
℃にて反応を開始し６時間重合したのち125℃ま
で昇温して２時間保持して重合を完了した。その
結果を第２表に示す。[Table] This data is for the case where the ratio of monomer to water is 1:2. MAA added at the start of polymerization
It has been shown that the amount is preferably about 30-80% of the total amount of MAA used. It can be seen that outside this range, the MAA content in the produced polymer changes greatly during the polymerization process, making the resulting polymer non-uniform, resulting in decreased heat resistance and impaired transparency. Example 2 This example shows the case where the ratio of monomer to water is 1:1. 2000 g of water and 6 g of PVA as a dispersant were added to the reactor No. 5, heated to 80° C., stirred and dissolved, and then 0.6 g of EDTA was added as an anti-emulsification agent. Next, 5 g of benzoyl peroxide and 2 g of tert-butyl peroxybenzoate were dissolved and added to 1700 g of styrene. methacrylic acid
As shown in Table 2, 300g was compared between adding it in parts and not adding it in parts. then 85
The reaction was started at .degree. C. and polymerized for 6 hours, then the temperature was raised to 125.degree. C. and maintained for 2 hours to complete the polymerization. The results are shown in Table 2.
【表】
モノマーの水の割合が１：１の場合でも重合開
始時と重合中に分割して添加する方が耐熱性、透
明性ですぐれていることがわかる。
実施例 ３
５の反応器に水2000ｇ、分散剤として実施例
１で用いたPVAを３ｇ加え80℃に昇温して撹拌
溶解したのち、乳化防止剤としてEDTA0.4ｇを
加えた。次にパラメチルスチレン850ｇにベンゾ
イルパーオキサイド2.5ｇ、ターシヤリブチルパ
ーオキシベンゾエート１ｇを溶解し加えた。メタ
クリル酸150ｇは第３表のように加えた。[Table] It can be seen that even when the ratio of water to monomer is 1:1, heat resistance and transparency are better when added separately at the start of polymerization and during polymerization. In the reactor of Example 3-5, 2000 g of water and 3 g of PVA used in Example 1 as a dispersant were added, the temperature was raised to 80° C., and the mixture was stirred and dissolved, and then 0.4 g of EDTA was added as an emulsification inhibitor. Next, 2.5 g of benzoyl peroxide and 1 g of tertiary butyl peroxybenzoate were dissolved and added to 850 g of paramethylstyrene. 150 g of methacrylic acid was added as shown in Table 3.
【表】
重合反応は85℃で６時間30分、粒子が固化して
から125℃まで昇温し２時間維持して重合を完了
させた。その結果得られた重合体のデーターは第
４表の通りである。[Table] The polymerization reaction was carried out at 85°C for 6 hours and 30 minutes. After the particles solidified, the temperature was raised to 125°C and maintained for 2 hours to complete the polymerization. The data of the resulting polymers are shown in Table 4.
【表】
(ハ) 発明の効果
本発明の製造方法によれば、優れた耐熱性及び
透明性を備えたスチレン―メタクリル酸系共重合
体を効率良く得ることができる。そして、前述の
ごとく使用する総単量体に対する水の割合を多く
することなく上記スチレン−メタクリル酸系共重
合体を得ることができるため生産性の点でも優れ
た方法であり、工業上極めて有用である。[Table] (c) Effects of the Invention According to the production method of the present invention, a styrene-methacrylic acid copolymer having excellent heat resistance and transparency can be efficiently obtained. As mentioned above, the styrene-methacrylic acid copolymer can be obtained without increasing the proportion of water to the total monomers used, so it is an excellent method in terms of productivity and is extremely useful industrially. It is.
Claims (1)
水媒体中に添加し懸濁重合条件に付してスチレン
系共重合体を製造する方法において、 添加する単量体の合計量と水媒体との割合が
１：0.8〜１：３（重量比）の範囲内でスチレン系
単量体とメタクリル酸単量体との添加比率を前
者：後者として95〜75重量％：５〜25重量％に設
定すると共に、添加するメタクリル酸単量体全量
の約30〜80％を実質的に全量のスチレン系単量体
と共に水媒体中に存在させて重合反応を開始し、
残りの約70〜20％を重合の進行に対応して断続的
又は連続的に後添加して共重合させることを特徴
とするスチレン系共重合体の製造方法。 ２ スチレン系単量体が、スチレン又はメチルス
チレンである特許請求の範囲第１項記載の製造方
法。[Scope of Claims] 1. A method for producing a styrenic copolymer by adding a styrene monomer and a methacrylic acid monomer to an aqueous medium and subjecting it to suspension polymerization conditions, comprising: The ratio of styrene monomer and methacrylic acid monomer to the total amount of the aqueous medium is within the range of 1:0.8 to 1:3 (weight ratio), and the ratio of the styrene monomer to the methacrylic acid monomer is 95 to 75% by weight as the former:the latter. : 5 to 25% by weight, and about 30 to 80% of the total amount of methacrylic acid monomers to be added is present in an aqueous medium together with substantially the entire amount of styrene monomer to initiate the polymerization reaction,
A method for producing a styrenic copolymer, characterized in that the remaining approximately 70 to 20% is post-added intermittently or continuously in accordance with the progress of polymerization. 2. The manufacturing method according to claim 1, wherein the styrenic monomer is styrene or methylstyrene.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10905485A JPS61266418A (en) | 1985-05-20 | 1985-05-20 | Production of styrene copolymer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10905485A JPS61266418A (en) | 1985-05-20 | 1985-05-20 | Production of styrene copolymer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61266418A JPS61266418A (en) | 1986-11-26 |
| JPH0380805B2 true JPH0380805B2 (en) | 1991-12-26 |
Family
ID=14500434
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10905485A Granted JPS61266418A (en) | 1985-05-20 | 1985-05-20 | Production of styrene copolymer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61266418A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6278023B2 (en) * | 2015-10-23 | 2018-02-14 | 日立化成株式会社 | Method for producing resin composition |
| JP6447665B2 (en) * | 2017-06-09 | 2019-01-09 | 日立化成株式会社 | Method for producing resin composition |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5062292A (en) * | 1973-10-01 | 1975-05-28 | ||
| JPS51119789A (en) * | 1975-04-14 | 1976-10-20 | Sumitomo Chem Co Ltd | Preparation of thermoplastic resins |
| JPS5718708A (en) * | 1980-05-29 | 1982-01-30 | Hoechst Co American | Manufacture of styrenic polymer particle |
| JPS5767606A (en) * | 1980-10-16 | 1982-04-24 | Badische Yuka Co Ltd | Preparation of grain of styrenic polymer |
-
1985
- 1985-05-20 JP JP10905485A patent/JPS61266418A/en active Granted
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5062292A (en) * | 1973-10-01 | 1975-05-28 | ||
| JPS51119789A (en) * | 1975-04-14 | 1976-10-20 | Sumitomo Chem Co Ltd | Preparation of thermoplastic resins |
| JPS5718708A (en) * | 1980-05-29 | 1982-01-30 | Hoechst Co American | Manufacture of styrenic polymer particle |
| JPS5767606A (en) * | 1980-10-16 | 1982-04-24 | Badische Yuka Co Ltd | Preparation of grain of styrenic polymer |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61266418A (en) | 1986-11-26 |
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