JPS6223782B2 - - Google Patents
Info
- Publication number
- JPS6223782B2 JPS6223782B2 JP53048334A JP4833478A JPS6223782B2 JP S6223782 B2 JPS6223782 B2 JP S6223782B2 JP 53048334 A JP53048334 A JP 53048334A JP 4833478 A JP4833478 A JP 4833478A JP S6223782 B2 JPS6223782 B2 JP S6223782B2
- Authority
- JP
- Japan
- Prior art keywords
- weight
- rubber
- polymerization
- soft component
- 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
Links
- 239000002245 particle Substances 0.000 claims description 28
- 239000011342 resin composition Substances 0.000 claims description 24
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 claims description 21
- 230000008961 swelling Effects 0.000 claims description 14
- 239000000203 mixture Substances 0.000 claims description 11
- 239000005063 High cis polybutadiene Substances 0.000 claims description 10
- 239000004610 Internal Lubricant Substances 0.000 claims description 10
- 150000001491 aromatic compounds Chemical class 0.000 claims description 4
- 230000000379 polymerizing effect Effects 0.000 claims description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 30
- 238000006116 polymerization reaction Methods 0.000 description 15
- 239000003973 paint Substances 0.000 description 10
- 229920001890 Novodur Polymers 0.000 description 9
- 238000000034 method Methods 0.000 description 9
- 229920000642 polymer Polymers 0.000 description 9
- 238000003756 stirring Methods 0.000 description 9
- 229920001971 elastomer Polymers 0.000 description 8
- 238000010438 heat treatment Methods 0.000 description 6
- 239000000178 monomer Substances 0.000 description 6
- 239000011248 coating agent Substances 0.000 description 5
- 238000000576 coating method Methods 0.000 description 5
- 239000000806 elastomer Substances 0.000 description 5
- 239000008188 pellet Substances 0.000 description 5
- 229920005989 resin Polymers 0.000 description 5
- 239000011347 resin Substances 0.000 description 5
- 239000005062 Polybutadiene Substances 0.000 description 4
- 239000013013 elastic material Substances 0.000 description 4
- 238000010422 painting Methods 0.000 description 4
- 229920002857 polybutadiene Polymers 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 3
- 238000012662 bulk polymerization Methods 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 239000005060 rubber Substances 0.000 description 3
- 229920003048 styrene butadiene rubber Polymers 0.000 description 3
- 239000004925 Acrylic resin Substances 0.000 description 2
- 229920000178 Acrylic resin Polymers 0.000 description 2
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 2
- 239000005064 Low cis polybutadiene Substances 0.000 description 2
- 239000002174 Styrene-butadiene Substances 0.000 description 2
- 238000007605 air drying Methods 0.000 description 2
- 239000008346 aqueous phase Substances 0.000 description 2
- DKPFZGUDAPQIHT-UHFFFAOYSA-N butyl acetate Chemical compound CCCCOC(C)=O DKPFZGUDAPQIHT-UHFFFAOYSA-N 0.000 description 2
- ZXEKIIBDNHEJCQ-UHFFFAOYSA-N isobutanol Chemical compound CC(C)CO ZXEKIIBDNHEJCQ-UHFFFAOYSA-N 0.000 description 2
- 239000002480 mineral oil Substances 0.000 description 2
- 235000010446 mineral oil Nutrition 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 150000003440 styrenes Chemical class 0.000 description 2
- 239000000725 suspension Substances 0.000 description 2
- 238000010557 suspension polymerization reaction Methods 0.000 description 2
- QORWJWZARLRLPR-UHFFFAOYSA-H tricalcium bis(phosphate) Chemical compound [Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O QORWJWZARLRLPR-UHFFFAOYSA-H 0.000 description 2
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 2
- 229920002554 vinyl polymer Polymers 0.000 description 2
- QMMJWQMCMRUYTG-UHFFFAOYSA-N 1,2,4,5-tetrachloro-3-(trifluoromethyl)benzene Chemical compound FC(F)(F)C1=C(Cl)C(Cl)=CC(Cl)=C1Cl QMMJWQMCMRUYTG-UHFFFAOYSA-N 0.000 description 1
- PAOHAQSLJSMLAT-UHFFFAOYSA-N 1-butylperoxybutane Chemical compound CCCCOOCCCC PAOHAQSLJSMLAT-UHFFFAOYSA-N 0.000 description 1
- XHAFIUUYXQFJEW-UHFFFAOYSA-N 1-chloroethenylbenzene Chemical compound ClC(=C)C1=CC=CC=C1 XHAFIUUYXQFJEW-UHFFFAOYSA-N 0.000 description 1
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 1
- 239000004342 Benzoyl peroxide Substances 0.000 description 1
- OMPJBNCRMGITSC-UHFFFAOYSA-N Benzoylperoxide Chemical compound C=1C=CC=CC=1C(=O)OOC(=O)C1=CC=CC=C1 OMPJBNCRMGITSC-UHFFFAOYSA-N 0.000 description 1
- SNRUBQQJIBEYMU-UHFFFAOYSA-N Dodecane Natural products CCCCCCCCCCCC SNRUBQQJIBEYMU-UHFFFAOYSA-N 0.000 description 1
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 description 1
- GWFGDXZQZYMSMJ-UHFFFAOYSA-N Octadecansaeure-heptadecylester Natural products CCCCCCCCCCCCCCCCCOC(=O)CCCCCCCCCCCCCCCCC GWFGDXZQZYMSMJ-UHFFFAOYSA-N 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- XYLMUPLGERFSHI-UHFFFAOYSA-N alpha-Methylstyrene Chemical compound CC(=C)C1=CC=CC=C1 XYLMUPLGERFSHI-UHFFFAOYSA-N 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- 235000019400 benzoyl peroxide Nutrition 0.000 description 1
- 125000000484 butyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 239000001506 calcium phosphate Substances 0.000 description 1
- 229910000389 calcium phosphate Inorganic materials 0.000 description 1
- 235000011010 calcium phosphates Nutrition 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- NRVKWKPZZQHRSP-UHFFFAOYSA-N cyclohexyl octadecanoate Chemical compound CCCCCCCCCCCCCCCCCC(=O)OC1CCCCC1 NRVKWKPZZQHRSP-UHFFFAOYSA-N 0.000 description 1
- 238000010908 decantation Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- GVGUFUZHNYFZLC-UHFFFAOYSA-N dodecyl benzenesulfonate;sodium Chemical compound [Na].CCCCCCCCCCCCOS(=O)(=O)C1=CC=CC=C1 GVGUFUZHNYFZLC-UHFFFAOYSA-N 0.000 description 1
- 125000003438 dodecyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000007720 emulsion polymerization reaction Methods 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 150000002168 ethanoic acid esters Chemical class 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- -1 for example Substances 0.000 description 1
- 239000012456 homogeneous solution Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 238000005461 lubrication Methods 0.000 description 1
- 230000000873 masking effect Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 150000002816 nickel compounds Chemical class 0.000 description 1
- NKBWPOSQERPBFI-UHFFFAOYSA-N octadecyl octadecanoate Chemical compound CCCCCCCCCCCCCCCCCCOC(=O)CCCCCCCCCCCCCCCCC NKBWPOSQERPBFI-UHFFFAOYSA-N 0.000 description 1
- 150000001451 organic peroxides Chemical class 0.000 description 1
- 238000007591 painting process Methods 0.000 description 1
- 150000002978 peroxides Chemical class 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 239000003505 polymerization initiator Substances 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 229940080264 sodium dodecylbenzenesulfonate Drugs 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000000375 suspending agent Substances 0.000 description 1
- 238000010558 suspension polymerization method Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Compositions Of Macromolecular Compounds (AREA)
- Graft Or Block Polymers (AREA)
Description
本発明は耐塗装性の改良された、高光沢を有す
るゴム変性スチレン系樹脂組成物に関する。
硬質で脆いスチレン系重合体の耐衝撃性を改良
するために、ゴム状弾性体とスチレン系重合体と
をブレンドしたり、ゴム状弾性体の存在下にスチ
レン系単量体を重合させたりしてゴム変性スチレ
ン系樹脂組成物とする事はよく知られている。従
来のゴム変性スチレン系樹脂組成物は、スチレン
系重合体に比べ耐衝撃性が向上する点ではその目
的を達しているが、反面、本来スチレン系重合体
のもつ優れた光沢が失われるという欠点があつ
た。しかしゴム状弾性体として１、４シス結合の
含量の多いポリブタジエンを使用することによつ
て優れた光沢をもつゴム変性スチレン系樹脂組成
物を得ることが可能になり（例えば特開昭52−
86444）一層商品価値が高まつた。
更に詳しく説明すると、ゴム変性スチレン系樹
脂組成物は軟質成分（スチレンとグラフト共重合
したゴム状弾性体とこれに封じこめられたスチレ
ン系重合体からなる）が粒子として分散してお
り、この軟質成分粒子の大きさと耐衝撃性、光沢
とは密接な関係がある。すなわち、軟質成分粒子
が大きい程耐衝撃性があがり、光沢がさがる。ゴ
ム変性スチレン系樹脂組成物を製造する際ゴム状
弾性体として上記の高シス含量ポリブタジエンを
使用する長所は、他のゴム状弾性体に比べ、同等
の耐衝撃性をもちながら、この樹脂組成物から成
形したものの表面に高い光沢を実現できる点にあ
る。このように高シス含量ポリブタジエンを使用
して得られた高光沢ゴム変性スチレン系樹脂組成
物は弱電機器、雑貨等の産業分野に使用されてい
る。具体的用途としてはテレビ、ラジオ、クリー
ナー等のハウジング、台所用品、種々の容器等が
ある。
さて、このような用途分野においては、成形物
自体の持つ優れた光沢を生かしつつ、さらに一層
商品価値を高める目的で成形物の一部に塗装を施
す場合が多い。しかし、塗装することによつて成
形物の耐衝撃性が塗装前に比べかなり低下すると
いう重大な欠点が存在するのである。
さらに詳しく説明すると、通常ゴム変性スチレ
ン系樹脂組成物の成形物への塗装は、塗装不要部
をマスキングして、スプレーガンを用いて実施さ
れる。
この際に使用する塗料は、塗装された塗膜の硬
さ、厚み、外観等の点で満足されるものが得ら
れ、かつ塗装工程が円滑になされるように選ばれ
た塗料樹脂とシンナーを調合して、調製される。
塗料樹脂としては常乾型アクリル樹脂が多く用い
られる。又シンナーとしては酢酸エステル類、ケ
トン類、アルコール類、芳香族化合物、セロソル
ブ類等を混合して用いる。このような塗装後の成
形物の耐衝撃性の低下は著しく、塗装前耐衝撃強
度の30％に低下することもある。
本発明の目的は、このような従来技術の欠点を
改良し、耐塗装性の改良された高光沢をもつスチ
レン系樹脂組成物を提供することである。
すなわち本発明は、シス１、４結合が90モル％
以上である高シスポリブタジエンを70重量％以上
含有するゴム状弾性体１〜10重量部とモノビニル
芳香族化合物90〜99重量部とを混合し、溶解し、
重合して得られる樹脂組成物において
(a) 組成物中に分散された軟質成分粒子が0.5〜
1.5μの平均粒径を有し、
(b) 軟質成分のトルエン中における膨潤指数が
9.5〜12であり、
(c) かつ、組成物に対して0.1重量部以上の内部
潤滑剤を含有する
ことを特徴とする樹脂組成物を提供する。
本発明の目的を達成するには、ゴム状弾性体と
して、高シスポリブタジエンを使用するゴム変性
スチレン系樹脂組成物において、上記の如く、軟
質成分粒子の粒径、軟質成分の膨潤指数および内
部潤滑剤の量をそれぞれ特定することが必要であ
り、これらの要件のどの一つが欠けても本発明の
目的は達成できない。
以下さらに詳しく説明する。
本発明の樹脂組成物を製造する方法は前記の特
徴が満足されるように配慮されているかぎり、任
意の公知の重合方法、例えば乳化重合法、塊状重
合法、塊状−懸濁重合法等を用いることができる
が、好ましくはゴム状弾性体の存在下にスチレン
を重合せしめる塊状重合法又は塊状−懸濁２段重
合法が適用される。例として塊状−懸濁２段重合
法について説明する。
まず、高シスポリブタジエンをスチレンに添加
し、60〜80℃に加熱、溶解する。この溶解はでき
るだけ均一であることが好ましい。次に90〜120
℃で撹拌下にスチレンの重合率が10〜40％になる
まで塊状重合を行なう。この工程を「予備重合工
程」と呼ぶこととし、この工程においてゴム状弾
性体の撹拌は撹伴の作用を受け粒子状に分散され
る。
予備重合工程終了後、第３リン酸カルシウム等
を懸濁剤として含む水相に懸濁し、懸濁重合を行
なう。重合は通常100％近くまで行なう。この予
備重合後の工程を「主重合工程」と呼ぶこととす
る。要すれば主重合工程に引き続き実質的に単量
体のない状態で加熱を続ける「后加熱工程」を行
なつても良い。
このようにして得たスラリーを脱水しビーズを
分取し、乾燥し、さらに押出工程でペレツト化す
る。
重合が完全に終つたとき、組成物中にはスチレ
ン系重合体の硬い相の中に軟質成分が粒子として
分散しており、この軟質成分はスチレンとグラフ
ト共重合したゴム状弾性体とこれに封じこめられ
たスチレン系重合体とからなつている。
本発明の目的を達するには、上記軟質成分の平
均粒径が0.5〜1.5μの範囲にあることが必要であ
る。平均粒径がこれ以外の範囲では他の諸要件を
本発明内に調整したとしても得られる樹脂組成物
の耐衝撃性、光沢は本発明の樹脂組成物に劣る。
即ち、平均粒径が0.5μ以下では、耐衝撃性が劣
り、粒径が1.5μ以上では光沢が劣る。
平均粒径とは樹脂の超薄切片法による電子顕微
鏡写真を撮影し写真中の軟質成分粒子200〜500個
の粒子径を測定し、次式により重量平均したもの
である。
重量平均径＝ΣnD4／ΣnD3
ここにｎは粒子径Ｄの軟質成分粒子の個数であ
る。
本発明で規定する平均粒径は予備重合工程の撹
拌条件を適切に定める事により達成できる。即
ち、撹拌翼の撹拌数を大きくすれば平均粒径は小
さくなり、撹拌数を小さくすれば平均粒径は大に
なるので適切な撹拌数を選択することにより所望
の平均粒径を達成できる。
本発明の目的を達成するためには軟質成分のト
ルエン中の膨潤指数が9.5〜12の範囲にあること
が必要である。この指数が上記範囲内にあつて、
かつ他の諸要件を満足するとき始めて塗装後の耐
衝撃性の低下を少なくできる。この範囲外即ち膨
潤指数が9.5以下であつても又12以上であつても
塗装した後の耐衝撃性は著しく低下する。
本発明でいう膨潤指数は次の方法で定められ
る。即ち、樹脂組成物2.00ｇを室温においてトル
エン40c.c.に溶解し、不溶のゲル分を遠心分離し、
溶液のデカンテーシヨンによつて単離し、湿つた
状態で秤量し、その後乾燥し再秤量する。膨潤指
数は次式で定義される。
膨潤指数
＝軟質成分の湿潤重量／軟質成分の乾燥重量
膨潤指数は溶剤の種類によつて異なるが本発明
に用いられる数値はトルエンに関するものであ
る。
本発明で規定する膨潤指数の調整は、公知の方
法で重合物を製造する際に、それぞれの製法にお
ける操業条件を定めることにより達成できる。普
通には、これは后加熱工程において適切な温度を
選ぶことおよび／又は架橋助剤たとえば過酸化物
の添加によつて調整される。即ち后加熱工程をよ
り高温にすれば重合物の膨潤指数は小さくなる
し、又この工程で有機過酸化物を添加する場合、
その分解量が多いほど膨潤指数が小さくなるので
ある。
本発明の目的を達成するには内部潤滑剤を0.1
重量％以上含有することが必要である。内部潤滑
剤が0.1重量％以下であると、たとえ他の諸要件
を満足しても、塗装による耐衝撃性の低下が大き
くなる。本発明の目的を達成するためには、内部
潤滑剤が0.1％以上であればよく、上限は特定す
る必要がないが、内部潤滑剤量が多くなると樹脂
組成物の軟化点が低下するので、実用上５％まで
が好ましい添加量である。
本発明で云う内部潤滑剤としては通常ポリスチ
レン添加用として使われている潤滑剤、例えば、
鉱油、ブチルステアレート、ステアリルステアレ
ート、シクロヘキシルステアレート等のエステル
類等が使用される。
本発明においては、シス−１、４結合を90モル
％以上有するポリブタジエンを70％重量以上含有
するゴム状弾性体を使用することが必要である。
この範囲外のゴム状弾性体を用いる場合は本発明
の対象とならない。即ち他のゴム状弾性体、例え
ばシス１、４結合が90モル％未満の低シスポリブ
タジエン、スチレン−ブタジエン共重合体ゴム
（SBR）等を用いたのでは他の諸要件を本発明の
範囲内に調整しても得られる樹脂組成物の光沢、
耐衝撃性が、本発明の如き高シスポリブタジエン
を用いた樹脂組成物に比較して、著しく劣つてい
るからである。
もちろん、本発明の目的を妨げない範囲で、即
ち全ゴム量の30重量％未満で、高シスポリブタジ
エン以外のゴム状弾性体、例えば低シスポリブタ
ジエン、SBR等を併用することは支障ない。
上記高シスポリブタジエンは、公知の方法例え
ば有機アルミニウム化合物とコバルト又はニツケ
ル化合物を含んでなる触媒を用いて１、３ブタジ
エンを重合して製造される。
上記高シスポリブタジエンの溶液粘度（５重量
％スチレン溶液の30℃における粘度）は本発明の
限定するところではないが、より優れた光沢を得
るには、溶液粘度は好ましくは30〜200センチス
トークスである事が望ましい。
本発明で使用されるモノビニル芳香族化合物と
はスチレン単独あるいはスチレンと共重合し得る
他のビニル系単量体とスチレンの混合物である。
スチレンと共重合し得る他のビニル系単量体と
は、例えばアクリロニトリル、メチルメタクリレ
ート、α−メチルスチレン、α−クロルスチレン
等である。これらの単量体は通常全単量体のうち
30重量％、好ましくは10重量％以下である。
以下、実施例により具体的に説明する。
実施例 １
内容積120の撹拌機付重合槽に
高シスポリブタジエン ７Kg
スチレン 93Kg
内部潤滑剤 1.0Kg
ターシヤリドデシルメチルカプタン 0.07Kg
（ここに高シスポリブタジエンは日本ゼオン社
製のニツポール1220であり、このゴムのシス１、
４結合含量は98.4モル％である。内部潤滑剤は出
光興産社製の鉱油CP−50である。）
を仕込み、撹拌下に65℃で５時間加熱し均一溶液
とした。その後、撹拌数を300rpmとして昇温
し、115℃で５時間重合を行ない、スチレンの重
合率を30％とした。そして、内容積300の撹拌
機付重合槽に下記の水相を用意し、上記予備重合
で得た重合混合物を加え粒子状に分散させた。
水 150Kg
第３リン酸カルシウム ３Kg
ドデシルベンゼンスルホン酸ソーダ 0.02Kg
この懸濁液にさらにベンゾイルパーオキサイド
0.20Kg、ジターシヤリブチルパーオキサイド0.02
Kgを添加し、90℃で７時間主重合を行なつた。そ
の後140℃で２時間、后加熱を行なつた。得られ
た懸濁粒子を別し乾燥し懸濁粒子100重量部に
対してBHT0.5重量部を加え押出機で押し出しペ
レツト化した。
この樹脂組成物中に分散された軟質成分の平均
粒径は1.0μであり、軟質成分のトルエン中にお
ける膨潤指数は10.9であつた。
実施例２、比較例１〜６
予備重合工程の撹拌数、内部潤滑剤量、重合開
始剤、后加熱工程の条件を表−１の如く変えた以
外は実施例１に従がい、実施例２、比較例１〜６
の樹脂組成物ペレツトを得た。比較例は本発明の
要求する要件の一部だけを満足するものである。
これらのペレツトを用い、射出成形により耐衝
撃性、光沢の測定用の試験片をつくり以下の測定
をした。結果は表−１にまとめた。
(1) 耐衝撃性の測定
50ｍ／ｍ×550ｍ／ｍ×2.5ｍ／ｍの角板に1/
４インチＲの撃芯をあて上部より一定荷重を落
下させ、試験片の50％が破壊するエネルギーを
もつて表わす。
破壊エネルギー（Kg・cm）＝荷重の落下高さ
（cm）×荷重（Kg）
(2) 光沢の測定
140ｍ／ｍ×80ｍ／ｍ×４ｍ／ｍの角板を成
形し、JIS K8741の方法によつてグロスを測定
した。
(3) 耐塗装性テスト
(1)と同じ角板に下記組成の塗料を塗膜が20μ
になるようにスプレーガンで塗装し、80℃で２
時間乾燥後、(1)と同様に耐衝撃性を測定した。
塗料の組成 樹脂：三井東圧社製常乾型アクリル
樹脂Ｌ−1090F
シンナ：酢酸エチル20％、酢酸ｎ−ブ
チル10％
IPA 10％、イソブタノール
30％
トルエン15％、ブチルセロソ
ルフ15％
樹脂とシンナーを１：１に混合して使用した。
実施例 ３〜５
原料であるゴム状弾性体と単量体を表−２の如
く変えた以外は実施例１に従つて樹脂組成物ペレ
ツトを得た。これらのペレツトは前記と同じく射
出成形して試験片をつくり、耐衝撃性、光沢を測
定し、耐塗装性をテストした。
結果を表−２に示す。
The present invention relates to a rubber-modified styrenic resin composition with improved paint resistance and high gloss. In order to improve the impact resistance of hard and brittle styrenic polymers, rubber-like elastomers and styrenic polymers are blended, or styrenic monomers are polymerized in the presence of rubber-like elastomers. It is well known that rubber-modified styrenic resin compositions can be prepared using rubber-modified styrene resin compositions. Conventional rubber-modified styrene-based resin compositions have achieved their goal in terms of improved impact resistance compared to styrene-based polymers, but on the other hand, they have the disadvantage of losing the excellent gloss that styrene-based polymers originally have. It was hot. However, by using polybutadiene with a high content of 1,4 cis bonds as a rubber-like elastic material, it has become possible to obtain rubber-modified styrenic resin compositions with excellent gloss (for example,
86444) The product value has further increased. To explain in more detail, the rubber-modified styrenic resin composition has a soft component (consisting of a rubbery elastic material graft-copolymerized with styrene and a styrenic polymer encapsulated therein) dispersed in the form of particles. There is a close relationship between the size of component particles, impact resistance, and gloss. That is, the larger the soft component particles, the higher the impact resistance and the lower the gloss. The advantage of using the above-mentioned high cis content polybutadiene as a rubbery elastomer when manufacturing a rubber-modified styrenic resin composition is that this resin composition has the same impact resistance as other rubbery elastomers. It is possible to achieve high gloss on the surface of molded materials. High-gloss rubber-modified styrenic resin compositions obtained using high-cis content polybutadiene are used in industrial fields such as light electrical equipment and miscellaneous goods. Specific applications include housings for televisions, radios, cleaners, etc., kitchen utensils, and various containers. Now, in such application fields, a part of the molded product is often painted in order to take advantage of the excellent gloss of the molded product itself and further increase its commercial value. However, there is a serious drawback in that by painting, the impact resistance of the molded product is considerably lower than before painting. To explain in more detail, coating of the rubber-modified styrenic resin composition on the molded article is usually carried out using a spray gun while masking unnecessary areas. The paint used at this time is a paint resin and thinner selected to ensure that the hardness, thickness, appearance, etc. of the painted film are satisfactory, and that the painting process is smooth. Mixed and prepared.
Air-drying acrylic resin is often used as paint resin. As the thinner, a mixture of acetic acid esters, ketones, alcohols, aromatic compounds, cellosolves, etc. is used. The impact resistance of molded products after painting is significantly reduced, sometimes to 30% of the impact strength before painting. It is an object of the present invention to overcome these drawbacks of the prior art and to provide a styrenic resin composition with improved paint resistance and high gloss. That is, in the present invention, the cis 1,4 bond is 90 mol%
1 to 10 parts by weight of the above-mentioned rubber-like elastic body containing 70% by weight or more of high-cis polybutadiene and 90 to 99 parts by weight of a monovinyl aromatic compound are mixed and dissolved,
In the resin composition obtained by polymerization, (a) the soft component particles dispersed in the composition are 0.5 to
It has an average particle size of 1.5μ, and (b) the swelling index of the soft component in toluene is
9.5 to 12, and (c) contains an internal lubricant of 0.1 part by weight or more based on the composition. In order to achieve the object of the present invention, in a rubber-modified styrenic resin composition using high-cis polybutadiene as a rubber-like elastic body, the particle size of the soft component particles, the swelling index of the soft component, and the internal lubrication are determined as described above. It is necessary to specify the amount of each agent, and the object of the present invention cannot be achieved if any one of these requirements is missing. This will be explained in more detail below. The method for producing the resin composition of the present invention may be any known polymerization method, such as emulsion polymerization, bulk polymerization, bulk-suspension polymerization, etc., as long as the above-mentioned characteristics are satisfied. Preferably, a bulk polymerization method or a bulk-suspension two-stage polymerization method in which styrene is polymerized in the presence of a rubber-like elastomer is used. As an example, a two-stage bulk-suspension polymerization method will be explained. First, high-cis polybutadiene is added to styrene and heated to 60-80°C to dissolve it. It is preferred that this dissolution be as uniform as possible. then 90-120
Bulk polymerization is carried out at ℃ under stirring until the polymerization rate of styrene reaches 10-40%. This step is referred to as a "prepolymerization step", and in this step, the rubber-like elastic body is stirred and dispersed into particles under the action of stirring. After the preliminary polymerization step is completed, the mixture is suspended in an aqueous phase containing tertiary calcium phosphate or the like as a suspending agent to carry out suspension polymerization. Polymerization is usually carried out to nearly 100%. The step after this preliminary polymerization will be referred to as the "main polymerization step." If necessary, a "post-heating step" in which heating is continued in a state substantially free of monomers may be performed following the main polymerization step. The slurry thus obtained is dehydrated, the beads are separated, dried, and pelletized in an extrusion process. When the polymerization is completely completed, the soft component is dispersed as particles in the hard phase of the styrene polymer in the composition, and this soft component is combined with the rubber-like elastic body graft-copolymerized with styrene. It is made up of encapsulated styrenic polymer. In order to achieve the object of the present invention, it is necessary that the average particle size of the soft component be in the range of 0.5 to 1.5 microns. If the average particle diameter is outside this range, even if other requirements are adjusted within the scope of the present invention, the resulting resin composition will have inferior impact resistance and gloss to the resin composition of the present invention.
That is, if the average particle size is 0.5 μm or less, the impact resistance will be poor, and if the particle size is 1.5 μm or more, the gloss will be poor. The average particle size is determined by taking an electron microscope photograph of the resin using an ultra-thin section method, measuring the particle diameters of 200 to 500 soft component particles in the photograph, and calculating the weight average using the following formula. Weight average diameter=ΣnD 4 /ΣnD 3 where n is the number of soft component particles having particle diameter D. The average particle size defined in the present invention can be achieved by appropriately determining the stirring conditions in the prepolymerization step. That is, increasing the stirring number of the stirring blade will reduce the average particle size, and decreasing the stirring number will increase the average particle size, so by selecting an appropriate stirring number, the desired average particle size can be achieved. In order to achieve the object of the present invention, it is necessary that the swelling index of the soft component in toluene be in the range of 9.5 to 12. If this index is within the above range,
The reduction in impact resistance after coating can be reduced only when other requirements are satisfied. If the swelling index is outside this range, that is, if the swelling index is 9.5 or less, or if it is 12 or more, the impact resistance after coating will be significantly reduced. The swelling index referred to in the present invention is determined by the following method. That is, 2.00 g of the resin composition was dissolved in 40 c.c. of toluene at room temperature, and the undissolved gel was centrifuged.
Isolate by decantation of the solution, weigh wet, then dry and reweigh. The swelling index is defined by the following formula. Swelling index = wet weight of soft component/dry weight of soft component Although the swelling index varies depending on the type of solvent, the numerical value used in the present invention relates to toluene. Adjustment of the swelling index defined in the present invention can be achieved by determining the operating conditions for each production method when producing a polymer by a known method. Usually this is adjusted by choosing a suitable temperature in the post-heating step and/or by adding crosslinking aids such as peroxides. That is, if the temperature of the post-heating step is made higher, the swelling index of the polymer will become smaller, and if an organic peroxide is added in this step,
The larger the amount of decomposition, the smaller the swelling index. To achieve the purpose of this invention, the internal lubricant should be 0.1
It is necessary to contain at least % by weight. If the internal lubricant is 0.1% by weight or less, even if other requirements are met, the impact resistance due to coating will be greatly reduced. In order to achieve the purpose of the present invention, it is sufficient that the internal lubricant is 0.1% or more, and there is no need to specify an upper limit, but as the amount of internal lubricant increases, the softening point of the resin composition decreases. Practically speaking, the preferred addition amount is up to 5%. The internal lubricant referred to in the present invention is a lubricant that is normally used for adding polystyrene, for example,
Mineral oil, esters such as butyl stearate, stearyl stearate, cyclohexyl stearate, etc. are used. In the present invention, it is necessary to use a rubber-like elastic body containing 70% or more by weight of polybutadiene having 90% by mole or more of cis-1,4 bonds.
If a rubber-like elastic body outside this range is used, it is not covered by the present invention. That is, if other rubber-like elastic materials are used, such as low-cis polybutadiene with less than 90 mol% of cis-1,4 bonds, styrene-butadiene copolymer rubber (SBR), etc., other requirements are not within the scope of the present invention. The gloss of the resin composition obtained even when adjusted to
This is because impact resistance is significantly inferior to resin compositions using high-cis polybutadiene such as those of the present invention. Of course, it is possible to use rubber-like elastic bodies other than high-cis polybutadiene, such as low-cis polybutadiene, SBR, etc., in combination, as long as the purpose of the present invention is not hindered, that is, less than 30% by weight of the total rubber amount. The above-mentioned high-cis polybutadiene is produced by a known method, for example, by polymerizing 1,3-butadiene using a catalyst containing an organoaluminum compound and a cobalt or nickel compound. The solution viscosity of the above-mentioned high-cis polybutadiene (viscosity at 30°C of a 5% styrene solution) is not a limitation of the present invention, but in order to obtain better gloss, the solution viscosity is preferably 30 to 200 centistokes. Something is desirable. The monovinyl aromatic compound used in the present invention is styrene alone or a mixture of styrene and other vinyl monomers that can be copolymerized with styrene.
Other vinyl monomers that can be copolymerized with styrene include, for example, acrylonitrile, methyl methacrylate, α-methylstyrene, α-chlorostyrene, and the like. These monomers usually account for
30% by weight, preferably 10% by weight or less. Hereinafter, this will be explained in detail using examples. Example 1 High cis polybutadiene 7 kg styrene 93 kg internal lubricant 1.0 kg tertiary dodecyl methylcaptan 0.07 kg (Here, the high cis polybutadiene is Nippor 1220 manufactured by Nippon Zeon Co., Ltd. rubber sis 1,
The 4-bond content is 98.4 mol%. The internal lubricant was mineral oil CP-50 manufactured by Idemitsu Kosan. ) and heated at 65°C for 5 hours with stirring to form a homogeneous solution. Thereafter, the temperature was raised to 300 rpm, and polymerization was carried out at 115° C. for 5 hours, resulting in a styrene polymerization rate of 30%. Then, the following aqueous phase was prepared in a polymerization tank with an internal volume of 300 and equipped with a stirrer, and the polymerization mixture obtained in the above prepolymerization was added and dispersed in the form of particles. Water 150Kg Calcium phosphate 3Kg Sodium dodecylbenzenesulfonate 0.02Kg Add benzoyl peroxide to this suspension.
0.20Kg, ditarsia butyl peroxide 0.02
Kg was added and main polymerization was carried out at 90°C for 7 hours. Thereafter, heating was performed at 140°C for 2 hours. The obtained suspended particles were separated and dried, and 0.5 parts by weight of BHT was added to 100 parts by weight of the suspended particles and extruded using an extruder to form pellets. The average particle size of the soft component dispersed in this resin composition was 1.0 μm, and the swelling index of the soft component in toluene was 10.9. Example 2, Comparative Examples 1 to 6 Example 1 was followed except that the number of stirrings in the prepolymerization step, the amount of internal lubricant, the polymerization initiator, and the conditions of the post-heating step were changed as shown in Table-1. , Comparative Examples 1 to 6
Resin composition pellets were obtained. The comparative example satisfies only part of the requirements of the present invention. Using these pellets, test pieces for measuring impact resistance and gloss were made by injection molding, and the following measurements were made. The results are summarized in Table-1. (1) Impact resistance measurement A square plate of 50m/m x 550m/m x 2.5m/m is
It is expressed as the energy required to break 50% of the test piece when a constant load is dropped from above using a 4-inch radius striking core. Fracture energy (Kg・cm) = Falling height of load (cm) x Load (Kg) (2) Measurement of gloss A square plate of 140 m/m x 80 m/m x 4 m/m was formed and processed according to the method of JIS K8741. Then, the gloss was measured. (3) Paint resistance test The same square plate as in (1) was coated with paint of the following composition to a coating film of 20 μm.
Paint with a spray gun and heat at 80℃ for 2
After drying for a period of time, impact resistance was measured in the same manner as in (1). Composition of paint Resin: Mitsui Toatsu air-drying acrylic resin L-1090F Thinner: ethyl acetate 20%, n-butyl acetate 10% IPA 10%, isobutanol
30% toluene 15%, butyl cellosol 15% Resin and thinner were mixed at a ratio of 1:1. Examples 3 to 5 Resin composition pellets were obtained in accordance with Example 1, except that the rubbery elastic material and monomer used as raw materials were changed as shown in Table 2. These pellets were injection molded in the same manner as above to make test pieces, and impact resistance and gloss were measured, and paint resistance was tested. The results are shown in Table-2.
【表】【table】
【表】【table】
Claims (1)
ポリブタジエンを70重量％以上含有するゴム状弾
性体１〜10重量部とモノビニル芳香族化合物90〜
99重量部とを混合し、溶解し、重合して得られる
樹脂組成物において (a) 組成物中に分散された軟質成分粒子が0.5〜
1.5μの平均粒径を有し (b) 軟質成分のトルエン中における膨潤指数が
9.5〜12であり (c) 且つ、前記組成物に対して0.1重量部以上の
内部潤滑剤を含有することを特徴とする樹脂組
成物。[Scope of Claims] 1. 1 to 10 parts by weight of a rubber-like elastic body containing 70% by weight or more of high-cis polybutadiene having 90% by mole or more of cis 1,4 bonds and 90 to 90% by weight of a monovinyl aromatic compound.
In the resin composition obtained by mixing, dissolving and polymerizing 99 parts by weight, (a) the soft component particles dispersed in the composition are 0.5 to
It has an average particle size of 1.5μ and (b) the swelling index of the soft component in toluene is
9.5 to 12, and (c) contains an internal lubricant of 0.1 part by weight or more based on the composition.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4833478A JPS54141838A (en) | 1978-04-25 | 1978-04-25 | Styrene resin composition |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4833478A JPS54141838A (en) | 1978-04-25 | 1978-04-25 | Styrene resin composition |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS54141838A JPS54141838A (en) | 1979-11-05 |
| JPS6223782B2 true JPS6223782B2 (en) | 1987-05-25 |
Family
ID=12800504
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4833478A Granted JPS54141838A (en) | 1978-04-25 | 1978-04-25 | Styrene resin composition |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS54141838A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01136085U (en) * | 1987-11-12 | 1989-09-18 | ||
| JPH0522190U (en) * | 1991-09-09 | 1993-03-23 | 弘治 毛利 | Brake lamp device for bicycle |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6011517A (en) * | 1983-07-01 | 1985-01-21 | Idemitsu Petrochem Co Ltd | Monovinyl aromatic resin composition |
| KR100413355B1 (en) * | 1998-07-21 | 2004-03-30 | 제일모직주식회사 | Styrene-based plastic resin composition with excellent antistatic property and surface gloss |
| US20170217263A1 (en) * | 2016-01-29 | 2017-08-03 | The Goodyear Tire & Rubber Company | Air maintenance tire |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4846691A (en) * | 1971-10-14 | 1973-07-03 |
-
1978
- 1978-04-25 JP JP4833478A patent/JPS54141838A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4846691A (en) * | 1971-10-14 | 1973-07-03 |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01136085U (en) * | 1987-11-12 | 1989-09-18 | ||
| JPH0522190U (en) * | 1991-09-09 | 1993-03-23 | 弘治 毛利 | Brake lamp device for bicycle |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS54141838A (en) | 1979-11-05 |
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