JPH0525897B2 - - Google Patents
Info
- Publication number
- JPH0525897B2 JPH0525897B2 JP63087305A JP8730588A JPH0525897B2 JP H0525897 B2 JPH0525897 B2 JP H0525897B2 JP 63087305 A JP63087305 A JP 63087305A JP 8730588 A JP8730588 A JP 8730588A JP H0525897 B2 JPH0525897 B2 JP H0525897B2
- Authority
- JP
- Japan
- Prior art keywords
- rubber
- microns
- gloss
- modified polystyrene
- weight
- 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
- 239000002245 particle Substances 0.000 claims description 71
- 239000004793 Polystyrene Substances 0.000 claims description 30
- 229920002223 polystyrene Polymers 0.000 claims description 30
- 229920001971 elastomer Polymers 0.000 claims description 25
- 239000005060 rubber Substances 0.000 claims description 23
- 239000011342 resin composition Substances 0.000 claims description 15
- 239000000203 mixture Substances 0.000 claims description 12
- 229920005990 polystyrene resin Polymers 0.000 claims description 9
- 229920000642 polymer Polymers 0.000 claims description 4
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 12
- 239000005062 Polybutadiene Substances 0.000 description 11
- 229920002857 polybutadiene Polymers 0.000 description 11
- 229920005989 resin Polymers 0.000 description 11
- 239000011347 resin Substances 0.000 description 11
- 230000007423 decrease Effects 0.000 description 8
- 238000003756 stirring Methods 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 241001237745 Salamis Species 0.000 description 3
- 229920000122 acrylonitrile butadiene styrene Polymers 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 238000006116 polymerization reaction Methods 0.000 description 3
- 230000000379 polymerizing effect Effects 0.000 description 3
- 235000015175 salami Nutrition 0.000 description 3
- 229920003048 styrene butadiene rubber Polymers 0.000 description 3
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 2
- 125000003118 aryl group Chemical group 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 235000014113 dietary fatty acids Nutrition 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 238000001125 extrusion Methods 0.000 description 2
- 229930195729 fatty acid Natural products 0.000 description 2
- 239000000194 fatty acid Substances 0.000 description 2
- 150000004665 fatty acids Chemical class 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 239000000314 lubricant Substances 0.000 description 2
- 239000000178 monomer Substances 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 150000003440 styrenes Chemical class 0.000 description 2
- OEVVKKAVYQFQNV-UHFFFAOYSA-N 1-ethenyl-2,4-dimethylbenzene Chemical compound CC1=CC=C(C=C)C(C)=C1 OEVVKKAVYQFQNV-UHFFFAOYSA-N 0.000 description 1
- NVZWEEGUWXZOKI-UHFFFAOYSA-N 1-ethenyl-2-methylbenzene Chemical compound CC1=CC=CC=C1C=C NVZWEEGUWXZOKI-UHFFFAOYSA-N 0.000 description 1
- JZHGRUMIRATHIU-UHFFFAOYSA-N 1-ethenyl-3-methylbenzene Chemical compound CC1=CC=CC(C=C)=C1 JZHGRUMIRATHIU-UHFFFAOYSA-N 0.000 description 1
- QEDJMOONZLUIMC-UHFFFAOYSA-N 1-tert-butyl-4-ethenylbenzene Chemical compound CC(C)(C)C1=CC=C(C=C)C=C1 QEDJMOONZLUIMC-UHFFFAOYSA-N 0.000 description 1
- JLBJTVDPSNHSKJ-UHFFFAOYSA-N 4-Methylstyrene Chemical compound CC1=CC=C(C=C)C=C1 JLBJTVDPSNHSKJ-UHFFFAOYSA-N 0.000 description 1
- 239000005063 High cis polybutadiene Substances 0.000 description 1
- 239000002174 Styrene-butadiene Substances 0.000 description 1
- 238000003917 TEM image Methods 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- XYLMUPLGERFSHI-UHFFFAOYSA-N alpha-Methylstyrene Chemical compound CC(=C)C1=CC=CC=C1 XYLMUPLGERFSHI-UHFFFAOYSA-N 0.000 description 1
- 150000001408 amides Chemical class 0.000 description 1
- 239000002216 antistatic agent Substances 0.000 description 1
- 229920001400 block copolymer Polymers 0.000 description 1
- 238000012662 bulk polymerization Methods 0.000 description 1
- MPMBRWOOISTHJV-UHFFFAOYSA-N but-1-enylbenzene Chemical compound CCC=CC1=CC=CC=C1 MPMBRWOOISTHJV-UHFFFAOYSA-N 0.000 description 1
- MTAZNLWOLGHBHU-UHFFFAOYSA-N butadiene-styrene rubber Chemical compound C=CC=C.C=CC1=CC=CC=C1 MTAZNLWOLGHBHU-UHFFFAOYSA-N 0.000 description 1
- CJZGTCYPCWQAJB-UHFFFAOYSA-L calcium stearate Chemical compound [Ca+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O CJZGTCYPCWQAJB-UHFFFAOYSA-L 0.000 description 1
- 239000008116 calcium stearate Substances 0.000 description 1
- 235000013539 calcium stearate Nutrition 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 239000000975 dye Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- -1 etc. Substances 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000006082 mold release agent Substances 0.000 description 1
- RKISUIUJZGSLEV-UHFFFAOYSA-N n-[2-(octadecanoylamino)ethyl]octadecanamide Chemical compound CCCCCCCCCCCCCCCCCC(=O)NCCNC(=O)CCCCCCCCCCCCCCCCC RKISUIUJZGSLEV-UHFFFAOYSA-N 0.000 description 1
- MMSLOZQEMPDGPI-UHFFFAOYSA-N p-Mentha-1,3,5,8-tetraene Chemical compound CC(=C)C1=CC=C(C)C=C1 MMSLOZQEMPDGPI-UHFFFAOYSA-N 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 239000004014 plasticizer Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000011115 styrene butadiene Substances 0.000 description 1
- 238000010558 suspension polymerization method Methods 0.000 description 1
- XOOUIPVCVHRTMJ-UHFFFAOYSA-L zinc stearate Chemical compound [Zn+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O XOOUIPVCVHRTMJ-UHFFFAOYSA-L 0.000 description 1
Description
〔産業上の利用分野〕
本発明は、優れた品質総合バランスを有する耐
衝撃性ポリスチレン樹脂組成物に関するものであ
る。
例えば、ゴム変性ポリスチレンは、家庭電機製
品の部品等に多く用いられているが、従来ABS
樹脂に比して、成形品表面の光沢に劣り、衝撃強
度も低く、着色した際の風合が及ばないと云う欠
点を有していた。最近、ABS樹脂の特性に近づ
いたゴム変性ポリスチレンの出現の要望がコスト
ダウン、薄肉化志向により市場から強まつて来て
いる。
本発明の樹脂組成物は、光沢、衝撃強度、剛性
の優れた品質総合バランスが射出成形品、押出シ
ート、押出真空成形等にて発現される。高価な
ABS樹脂からの代替、製品薄肉化が可能となり、
コストダウンを図れる経済的な樹脂としての価値
は大である。
〔従来の技術〕
ゴム変性ポリスチレンは、従来から工業的に多
く用いられているが、その分散ゴム粒子径は一般
に1.0〜5.0ミクロン程度であり、最近は成形品の
光沢を向上させるためにゴム粒子径の小さいもの
が開発上市されて来ているが、1.0ミクロン以下
の小さいゴム粒子径の場合には衝撃強度の低下が
著しく、好ましい樹脂は得られていない。又、衝
撃強度と光沢のバランスを改良するために1.0ミ
クロン以下の小さなゴム粒子径を有するゴム変性
ポリスチレンと大きなゴム粒子径を有するゴム変
性ポリスチレンとのブレンドからなる組成物が、
特公昭46−41467号公報、特公昭59−1519号公報、
米国特許第4146589号明細書、米国特許第4214056
号明細書、米国特許第4493922号明細書等の先行
文献に述べられているが、使用されている大粒子
が２ミクロン以上と大きいために成形品の外観が
劣り、特に光沢勾配が大きい（成形品においてゲ
ートからの遠い個所の光沢の低下が大きい）、金
型温度の低い条件で成形されると、光沢が十分で
ないなどの問題があつた。
〔発明が解決しようとする問題点〕
先に述べた優れた品質総合バランスを有するゴ
ム変性ポリスチレンに対する市場の要望に合致す
るには、優れた成形品外観（特に光沢値が高く光
沢勾配の小さいこと）、衝撃強度、剛性の品質バ
ランスの良いゴム変性ポリスチレン樹脂が必要と
なる。
本発明の目的は、上記の優れた成形品外観、衝
撃強度、剛性の品質バランスの優れた安価な耐衝
撃性ポリスチレン樹脂を提供することである。
〔問題点を解決するための手段〕
この目的は、特定のミクロ構造を有するゴム変
性ポリスチレンよりなる本発明の樹脂組成物によ
つ達成される。
即ち、本発明は、耐衝撃性ポリスチレン樹脂組
成物において、該組成物中のゴム変性ポリスチレ
ン中のゴム状重合体が粒子状に分散しており、そ
の分散粒子は小粒子部分と大粒子部分との二つの
山からなる分布を示し、小粒子部分の平均粒子径
が0.1〜0.6ミクロンであり、かつ単一オクルージ
ヨン構造を有し、大粒子部分の平均粒子径が0.7
〜2.0ミクロンであることを特徴とする光沢と耐
衝撃性に優れたポリスチレン樹脂組成物に関する
ものである。
本発明のゴム変性ポリスチレンは、ゴム状重合
体の存在下に芳香族モノビニル単量体を重合せし
める塊状重合法又は塊状懸濁重合法で製造するこ
とができる。本発明に特定された特殊なミクロ構
造を有するゴム変性ポリスチレンは、重合工程に
おける撹拌の状態、ゴム粒子生成時の混合状態な
どをコントロールすることにより製造することが
できる。
芳香族モノビニル単量体としては、スチレン及
びｏ−メチルスチレン、ｐ−メチルスチレン、ｍ
−メチルスチレン、２，４−ジメチルスチレン、
エチルスチレン、ｐ−tert−ブチルスチレン等の
核アルキル置換スチレン、α−メチルスチレン、
α−メチル−ｐ−メチルスチレン等のα−アルキ
ル置換スチレンなどが用いられる。又、ゴム状重
合体としては、ポリブタジエン、スチレン−ブタ
ジエン共重合体等であり、ポリブタジエンとして
はシス含有量の高いハイシスポリブタジエン共に
用いることができる。
本発明においてゴム粒子径の分布が二つ山から
なる分布を示すゴム変性ポリスチレンは、小粒子
ゴムを含有するゴム変性ポリスチレンと大粒子ゴ
ムを含有するゴム変性ポリスチレンとを別々に造
り、押出機などでブレンドすることにより製造す
ることもできるし、小粒子ゴムと大粒子ゴムとを
重合反応器にて混合することにより製造すること
もできる。
小粒子部分の平均粒径は0.1〜0.6ミクロンであ
ることが必要であり、好ましくは0.2〜0.5ミクロ
ンである。この平均粒子径が0.1ミクロン未満で
は衝撃強度が低下し、又、0.6ミクロンを超える
と成形品の外観、特に光沢勾配が大きくなり、
又、光沢の低下が見られ好ましくない。更に小粒
子ゴムは、単一オクルージヨン構造（シエル／コ
ア型とも言われる）を有していることが、光沢と
耐衝撃強度のバランスを保つために必要である。
このような小粒子ゴムは、スチレンとブタジエン
のブロツク共重合体の存在下で撹拌下にスチレン
を重合することによつて効率的に製造することが
できる。又、大粒子部分の平均粒径は0.7〜2.0ミ
クロンであることが必要であり、好ましくは1.0
〜1.5ミクロンである。この平均粒子径が0.7ミク
ロン未満では衝撃強度が低下し、又、2.0ミクロ
ンを超えると成形品の外観、特に光沢勾配が大き
くなり、又、金型温度の低い条件で成形される
と、光沢が不十分となるなどの点で好ましくな
い。又、ゴム粒子径分布は小粒子部分と大粒子部
分からなる二つの山からなる分布を有しているこ
とが成形品外観、衝撃強度、剛性の品質バランス
の優れた樹脂を与えている。
ここで云う平均粒子径とは、ゴム変性ポリスチ
レンの超薄切片法による透過型電子顕微鏡写真を
撮影し、写真中のゴム状重合体粒子1000個の粒子
径を測定し、次式により算出したものである。
平均粒子径＝Σni・Di4／Σni・Di3
（ここにniは粒子径Diのゴム状重合体粒子の個
数である。）
又、本発明において、組成中のゴムの総量の20
〜95重量％、好ましくは50〜90重量％、最も好ま
しくは60〜80重量％が小粒子部分であり、５〜80
重量％、好ましくは10〜50重量％、最も好ましく
は20〜40重量％が大粒子部分である。小粒子部分
が20重量％未満では成形品外観が低下し、95重量
％を超えると衝撃強度が低下し好ましくない。
又、本発明に用いるゴム変性ポリスチレンは良
好な成形品外観を得るために、実質上２ミクロン
以上の大きなゴム粒子を含有していないことが好
ましい。実質上含有していないとは、２ミクロン
以上のゴム粒子が組成物中のゴムの総量の20重量
％以下、好ましくは５重量％以下であることを示
す。組成物中に２ミクロン以上の大きなゴム粒子
が20重量％以上存在すると、光沢勾配が大きくな
り、又、低い金型温度で得た成形品の光沢が低下
するなどして、好ましい成形品外観を得ることが
できない。
本発明の耐衝撃性ポリスチレン樹脂組成物に
は、高級脂肪酸の金属塩、例えば、ステアリン酸
亜鉛、ステアリン酸カルシウム等、高級脂肪酸の
アミド類、例えば、エチレンビスステアロアミド
等の滑剤を組合せて用いることにより、衝撃強度
及び光沢の点で好ましい結果が得られる。用いる
滑剤の量は0.01〜1.0重量％、好ましくは0.01〜
0.2重量％である。
又、本発明の耐衝撃性ポリスチレン樹脂組成物
には、染顔料、滑剤、充填剤、離型剤、可塑剤、
帯電防止剤等の添加剤を必要に応じて添加するこ
とができる。
〔発明の効果〕
本発明の樹脂組成物は衝撃強度、光沢、剛性の
物性面での品質総合バランスに優れる。このよう
な特性を有することから特に大型の射出成形品を
得るための樹脂として非常に好ましい。
本発明の樹脂組成物は、弱電機器、雑貨等の分
野において成形品として使用できる。特に鮮明な
外観が要求される成形品において好ましい結果を
得ることができる。
〔実施例〕
以下に実施例を示す。なお、実施例に示された
データーは次の方法に基づいて測定されたもので
ある。
アイゾツト衝撃強度：ASTM D256によつた。
曲げ強さ、曲げ弾性率：ASTM D759によつた。
光沢：ASTM D638のダンベル試験片のゲート
部とエンドゲート部の光沢度を測定した。
実施例１〜５及び比較例１、２
スチレン−ブタジエンブロツク共重合体の存在
下にスチレンモノマーを撹拌下で重合することに
よつて得た平均粒子径が0.2ミクロンで単一オク
ルージヨン構造を有し、樹脂中のポリブタジエン
成分の含有量が９重量％であるゴム変性ポリスチ
レン(A)と、ポリブタジエンの存在下にスチレンモ
ノマーを撹拌下で重合することによつて得た平均
粒子径が1.5ミクロンでサラミ構造を有し、樹脂
中のポリブダシエン成分の含有量が12重量％であ
るゴム変性ポリスチレン(B)とを第１表に示した比
率で混合し、押出機で溶融混練して樹脂組成物を
得た。該樹脂組成物の光沢、アイゾツト衝撃強
度、曲げ弾性率を評価した。この結果を第１表に
示す。
小粒子径ゴム粒子を含有するゴム変性ポリスチ
レン(A)と大粒子径ゴム粒子を含有するゴム変性ポ
リスチレン(B)とを適当な比率で配合することによ
つて光沢、特にエンドゲート部の光沢値が良好で
著しく衝撃強度の高い組成物が得られる。ゴム変
性ポリスチレン(A)単独の場合には衝撃強度の優れ
た組成物は得られない。
実施例６、７及び比較例３、４
ポリブタジエンの存在下にスチレンモノマーを
撹拌下で重合し、その際の撹拌力の強さをコント
ロールすることによつて得た平均粒子径が0.6ミ
クロン、0.9ミクロン、1.5ミクロン2.7ミクロン、
でサラミ構造を有し、樹脂中のポリブタジエン成
分の含有量が12重量％である４種のゴム変性ポリ
スチレン(B)を得た。ここで得たゴム変性ポリスチ
レン(B)25重量％と実施例１〜５で用いたゴム変性
ポリスチレン(A)75重量％を、第２表に示す如く加
え、実施例１と同様に樹脂組成物を得て物性を評
価した。その結果を第２表に示す。ゴム変性ポリ
スチレン(A)と組合せるゴム変性ポリスチレンの平
均粒子径が２ミクロンを超えると光沢勾配が大き
くなり（エンドゲート部の光沢が低い）好ましく
ない結果を示している。又、平均粒子径が0.6ミ
クロンと小さくなると衝撃強度が低下して好まし
くない。
比較例 ５
実施例３におけるゴム変性ポリスチレン(A)に代
えて平均粒子径が0.7ミクロンでサラミ構造を有
し、樹脂中のポリブタジエン成分の含有量が９重
量％であるゴム変性ポリスチレンを用いて同様の
評価を行つた。その結果を第２表に示す。光沢勾
配が大きくなり好ましくない。
比較例 ６
実施例３において、平均粒子径が0.2ミクロン
で単一オクルージヨン構造を有し、樹脂中のポリ
ブタジエン成分の含有量が９重量％であるゴム変
性ポリスチレンに代えて、ポリブタジエン及びス
チレン−ブタジエンブロツク共重合体の存在下に
スチレンモノマーを撹拌下で重合することによつ
て得た平均粒子径が0.2ミクロンで大部分が単一
オクルージヨン構造でなく樹脂中のポリブタジエ
ンの含有量が９重量％であるゴム変性ポリスチレ
ンを用いる他は同様にして樹脂組成物を得、同様
の評価を行つた。アイゾト衝撃強度4.5Kg・cm／
cm、光沢：エンドゲート部98％、ゲート部89％；
曲げ弾性率25000Kg／cm2であつた。
小粒子ゴムが単一オクルージヨン構造を有しな
いと、衝撃強度が劣る。
[Industrial Application Field] The present invention relates to an impact-resistant polystyrene resin composition having an excellent overall quality balance. For example, rubber-modified polystyrene is often used in parts of home appliances, but conventional ABS
Compared to resins, they have the disadvantages of inferior gloss on the surface of molded products, low impact strength, and poor texture when colored. Recently, there has been a growing demand in the market for rubber-modified polystyrene that has properties close to those of ABS resin due to the desire for cost reduction and thinner walls. The resin composition of the present invention exhibits an excellent overall quality balance of gloss, impact strength, and rigidity in injection molded products, extrusion sheets, extrusion vacuum molding, and the like. Expensive
It becomes possible to replace ABS resin and make products thinner.
It has great value as an economical resin that can reduce costs. [Prior art] Rubber-modified polystyrene has been widely used industrially, but the dispersed rubber particle size is generally about 1.0 to 5.0 microns, and recently rubber particles have been used to improve the gloss of molded products. Rubber particles with small diameters have been developed and put on the market, but in the case of small rubber particle diameters of 1.0 microns or less, the impact strength decreases significantly, and a desirable resin has not been obtained. In addition, in order to improve the balance between impact strength and gloss, a composition consisting of a blend of rubber-modified polystyrene with a small rubber particle size of 1.0 microns or less and a rubber-modified polystyrene with a large rubber particle size,
Special Publication No. 46-41467, Publication No. 59-1519,
U.S. Patent No. 4146589, U.S. Patent No. 4214056
However, because the large particles used are as large as 2 microns or more, the appearance of the molded product is poor, and the gloss gradient is especially large (molding There were problems such as a large drop in gloss in areas far from the gate) and insufficient gloss when molded at low mold temperatures. [Problems to be solved by the invention] In order to meet the market demand for rubber-modified polystyrene having an excellent overall quality balance as described above, it is necessary to have excellent molded product appearance (especially high gloss value and small gloss gradient). ), a rubber-modified polystyrene resin with a good balance of impact strength and rigidity is required. An object of the present invention is to provide an inexpensive impact-resistant polystyrene resin that has an excellent quality balance between the above-mentioned excellent appearance of molded products, impact strength, and rigidity. [Means for solving the problem] This object is achieved by the resin composition of the present invention, which consists of rubber-modified polystyrene having a specific microstructure. That is, the present invention provides an impact-resistant polystyrene resin composition in which the rubber-like polymer in the rubber-modified polystyrene in the composition is dispersed in the form of particles, and the dispersed particles are divided into small particle portions and large particle portions. It shows a distribution consisting of two peaks, the average particle size of the small particle part is 0.1 to 0.6 microns, and has a single occlusion structure, and the average particle size of the large particle part is 0.7
This invention relates to a polystyrene resin composition with excellent gloss and impact resistance, characterized by a particle size of ~2.0 microns. The rubber-modified polystyrene of the present invention can be produced by a bulk polymerization method or a bulk suspension polymerization method in which an aromatic monovinyl monomer is polymerized in the presence of a rubbery polymer. The rubber-modified polystyrene having the special microstructure specified in the present invention can be produced by controlling the stirring state during the polymerization process, the mixing state during rubber particle production, and the like. Aromatic monovinyl monomers include styrene, o-methylstyrene, p-methylstyrene, m
-methylstyrene, 2,4-dimethylstyrene,
Nuclear alkyl-substituted styrene such as ethylstyrene, p-tert-butylstyrene, α-methylstyrene,
α-alkyl substituted styrene such as α-methyl-p-methylstyrene is used. Further, examples of the rubbery polymer include polybutadiene, styrene-butadiene copolymer, etc., and high-cis polybutadiene having a high cis content can also be used as the polybutadiene. In the present invention, the rubber-modified polystyrene exhibiting a two-peak distribution of rubber particle diameters is obtained by separately producing rubber-modified polystyrene containing small-particle rubber and rubber-modified polystyrene containing large-particle rubber, and using an extruder or the like. It can also be produced by blending small particle rubber and large particle rubber in a polymerization reactor. The average particle size of the small particle portion should be 0.1 to 0.6 microns, preferably 0.2 to 0.5 microns. If the average particle size is less than 0.1 micron, the impact strength will decrease, and if it exceeds 0.6 micron, the appearance of the molded product, especially the gloss gradient, will increase.
In addition, a decrease in gloss is observed, which is not preferable. Furthermore, it is necessary for the small particle rubber to have a single occlusion structure (also referred to as shell/core type) in order to maintain a balance between gloss and impact strength.
Such small particle rubbers can be efficiently produced by polymerizing styrene under stirring in the presence of a block copolymer of styrene and butadiene. In addition, the average particle size of the large particle portion needs to be 0.7 to 2.0 microns, preferably 1.0 microns.
~1.5 micron. If the average particle size is less than 0.7 microns, the impact strength will decrease, and if it exceeds 2.0 microns, the appearance of the molded product, especially the gloss gradient will become large, and if molded at a low mold temperature, the gloss will decrease. This is not preferable because it may be insufficient. Furthermore, the rubber particle size distribution has a two-peak distribution consisting of a small particle portion and a large particle portion, which provides a resin with an excellent quality balance of molded product appearance, impact strength, and rigidity. The average particle diameter referred to here is calculated by taking a transmission electron micrograph of rubber-modified polystyrene using an ultra-thin section method, measuring the particle diameter of 1000 rubber-like polymer particles in the photograph, and using the following formula. It is. Average particle size = Σni・Di 4 /Σni・Di 3 (here, ni is the number of rubber-like polymer particles with a particle size Di).
~95% by weight, preferably 50-90%, most preferably 60-80% by weight are small particle fractions, and 5-80% by weight
% by weight, preferably 10-50% by weight, most preferably 20-40% by weight, is the large particle portion. If the small particle portion is less than 20% by weight, the appearance of the molded product will deteriorate, and if it exceeds 95% by weight, the impact strength will decrease, which is not preferable. Further, in order to obtain a good appearance of the molded product, the rubber-modified polystyrene used in the present invention preferably does not substantially contain large rubber particles of 2 microns or more. "Substantially free" means that rubber particles of 2 microns or larger account for 20% by weight or less, preferably 5% by weight or less of the total amount of rubber in the composition. If 20% by weight or more of large rubber particles of 2 microns or more are present in the composition, the gloss gradient becomes large and the gloss of molded products obtained at low mold temperatures decreases, resulting in unfavorable molded product appearance. can't get it. The impact-resistant polystyrene resin composition of the present invention may be used in combination with metal salts of higher fatty acids such as zinc stearate and calcium stearate, and amides of higher fatty acids such as ethylene bisstearamide. This gives favorable results in terms of impact strength and gloss. The amount of lubricant used is 0.01 to 1.0% by weight, preferably 0.01 to 1.0% by weight.
It is 0.2% by weight. The impact-resistant polystyrene resin composition of the present invention also contains dyes and pigments, lubricants, fillers, mold release agents, plasticizers,
Additives such as antistatic agents can be added as necessary. [Effects of the Invention] The resin composition of the present invention has an excellent overall quality balance in terms of physical properties such as impact strength, gloss, and rigidity. Because it has such properties, it is very preferable as a resin particularly for obtaining large injection molded products. The resin composition of the present invention can be used as a molded article in fields such as light electrical equipment and miscellaneous goods. Particularly favorable results can be obtained in molded products that require a clear appearance. [Example] Examples are shown below. Note that the data shown in Examples was measured based on the following method. Izot impact strength: According to ASTM D256. Bending strength, bending modulus: According to ASTM D759. Gloss: The gloss of the gate and end gate portions of the ASTM D638 dumbbell test piece was measured. Examples 1 to 5 and Comparative Examples 1 and 2 Polymerization of styrene monomer with stirring in the presence of a styrene-butadiene block copolymer had an average particle diameter of 0.2 microns and a single occlusion structure. , a salami with an average particle diameter of 1.5 microns obtained by polymerizing rubber-modified polystyrene (A) in which the content of the polybutadiene component in the resin is 9% by weight and a styrene monomer in the presence of polybutadiene under stirring. rubber-modified polystyrene (B) having a polybutadiene component content of 12% by weight in the resin is mixed in the ratio shown in Table 1, and melt-kneaded using an extruder to obtain a resin composition. Ta. The gloss, Izot impact strength, and flexural modulus of the resin composition were evaluated. The results are shown in Table 1. By blending rubber-modified polystyrene (A) containing small-sized rubber particles and rubber-modified polystyrene (B) containing large-sized rubber particles in an appropriate ratio, gloss, especially the gloss value of the end gate area, can be improved. A composition with good impact strength and significantly high impact strength can be obtained. If rubber-modified polystyrene (A) is used alone, a composition with excellent impact strength cannot be obtained. Examples 6 and 7 and Comparative Examples 3 and 4 Styrene monomer was polymerized in the presence of polybutadiene with stirring, and the average particle diameter obtained by controlling the strength of the stirring force at that time was 0.6 microns and 0.9 micron, 1.5 micron 2.7 micron,
Four types of rubber-modified polystyrene (B) having a salami structure and containing a polybutadiene component in the resin of 12% by weight were obtained. 25% by weight of the rubber-modified polystyrene (B) obtained here and 75% by weight of the rubber-modified polystyrene (A) used in Examples 1 to 5 were added as shown in Table 2, and a resin composition was prepared in the same manner as in Example 1. was obtained and the physical properties were evaluated. The results are shown in Table 2. When the average particle diameter of the rubber-modified polystyrene used in combination with the rubber-modified polystyrene (A) exceeds 2 microns, the gloss gradient becomes large (the gloss at the end gate part is low), which is an unfavorable result. Moreover, if the average particle diameter is as small as 0.6 microns, the impact strength decreases, which is not preferable. Comparative Example 5 The same procedure was carried out using rubber-modified polystyrene having an average particle diameter of 0.7 microns, a salami structure, and a polybutadiene component content of 9% by weight in the resin in place of the rubber-modified polystyrene (A) in Example 3. We conducted an evaluation. The results are shown in Table 2. The gloss gradient becomes large, which is not preferable. Comparative Example 6 In Example 3, polybutadiene and styrene-butadiene block were used in place of the rubber-modified polystyrene having an average particle diameter of 0.2 microns and a single occlusion structure, and the content of the polybutadiene component in the resin was 9% by weight. Obtained by polymerizing styrene monomer in the presence of a copolymer with stirring, the average particle size is 0.2 microns, most of the particles do not have a single occlusion structure, and the content of polybutadiene in the resin is 9% by weight. A resin composition was obtained in the same manner except that rubber-modified polystyrene was used, and the same evaluation was performed. Izoto impact strength 4.5Kg・cm/
cm, gloss: end gate 98%, gate 89%;
The flexural modulus was 25000 Kg/cm 2 . If the small particle rubber does not have a single occlusion structure, the impact strength will be poor.
【表】【table】
Claims (1)
該組成物中のゴム変性ポリスチレン中にゴム状重
合体が粒子状に分散しており、その分散粒子は小
粒子部分と大粒子部分との二つの山からなる分布
を示し、小粒子部分の平均粒子径が0.1〜0.6ミク
ロンであり、かつ単一オクルージヨン構造を有
し、大粒子部分の平均粒子径が0.7〜2.0ミクロン
であることを特徴とする光沢と耐衝撃性に優れた
ポリスチレン樹脂組成物。 ２ 組成物中のゴムの総量の20〜95重量％が小粒
子部分であり、５〜80重量％が大粒子部分である
特許請求の範囲第１項記載の組成物。 ３ 小粒子部分の平均粒子径が0.2〜0.5ミクロン
である特許請求の範囲第１項又は第２項記載の組
成物。 ４ 大粒子部分の平均粒子径が1.0〜1.5ミクロン
である特許請求の範囲第１項又は第２項記載の組
成物。[Claims] 1. In an impact-resistant polystyrene resin composition,
The rubber-like polymer is dispersed in the form of particles in the rubber-modified polystyrene in the composition, and the dispersed particles exhibit a distribution consisting of two peaks, a small particle portion and a large particle portion, and the average of the small particle portion is A polystyrene resin composition with excellent gloss and impact resistance, which has a particle diameter of 0.1 to 0.6 microns, has a single occlusion structure, and has an average particle diameter of 0.7 to 2.0 microns in the large particle portion. . 2. The composition according to claim 1, wherein 20 to 95% by weight of the total amount of rubber in the composition is a small particle portion and 5 to 80% by weight is a large particle portion. 3. The composition according to claim 1 or 2, wherein the average particle diameter of the small particle portion is 0.2 to 0.5 microns. 4. The composition according to claim 1 or 2, wherein the average particle diameter of the large particle portion is 1.0 to 1.5 microns.
Priority Applications (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63087305A JPH01261444A (en) | 1988-04-11 | 1988-04-11 | Polystyrene resin composition of excellent gloss and impact resistance |
| CA000595991A CA1335524C (en) | 1988-04-11 | 1989-04-07 | Rubber-modified polystyrene resin composition |
| EP89200897A EP0337569B2 (en) | 1988-04-11 | 1989-04-10 | Rubber-modified polystyrene resin composition |
| DE1989604796 DE68904796T2 (en) | 1988-04-11 | 1989-04-10 | Rubber modified polystyrene resin composition. |
| US07/335,373 US5039714A (en) | 1988-04-11 | 1989-04-10 | Rubber-modified polystyrene resin composition |
| KR1019890004774A KR920001046B1 (en) | 1986-10-29 | 1989-04-11 | Rubber-modified polystyrene resin composition |
| TW078102842A TW197460B (en) | 1986-10-29 | 1989-04-17 | |
| SG113094A SG113094G (en) | 1988-04-11 | 1994-08-13 | Rubber-modified polystyrene resin composition |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63087305A JPH01261444A (en) | 1988-04-11 | 1988-04-11 | Polystyrene resin composition of excellent gloss and impact resistance |
| SG113094A SG113094G (en) | 1988-04-11 | 1994-08-13 | Rubber-modified polystyrene resin composition |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01261444A JPH01261444A (en) | 1989-10-18 |
| JPH0525897B2 true JPH0525897B2 (en) | 1993-04-14 |
Family
ID=26428594
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63087305A Granted JPH01261444A (en) | 1986-10-29 | 1988-04-11 | Polystyrene resin composition of excellent gloss and impact resistance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01261444A (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2651491B2 (en) * | 1988-07-28 | 1997-09-10 | 出光石油化学株式会社 | High gloss impact resistant styrenic resin composition |
| JPH0238435A (en) * | 1988-07-28 | 1990-02-07 | Idemitsu Petrochem Co Ltd | Styrene resin composition |
| JP2645409B2 (en) * | 1990-01-26 | 1997-08-25 | 出光石油化学株式会社 | High gloss impact resistant styrenic resin composition |
| JP2657287B2 (en) * | 1990-01-26 | 1997-09-24 | 出光石油化学株式会社 | Styrene resin composition |
| JP2683613B2 (en) * | 1990-01-30 | 1997-12-03 | 出光石油化学株式会社 | Injection molded products made of styrene resin |
| JP2683614B2 (en) * | 1990-01-30 | 1997-12-03 | 出光石油化学株式会社 | Rubber modified styrenic resin composition |
| US5473014A (en) * | 1992-03-23 | 1995-12-05 | Mitsui Toatsu Chemicals, Incorporated | Rubber modified styrenic resin composition having high gloss and impact strength |
| KR100411088B1 (en) * | 2001-08-17 | 2003-12-18 | 제일모직주식회사 | Styrenic Resin Composition with Excellent Heat Resistance and Surface Gloss |
| KR100443211B1 (en) * | 2001-10-19 | 2004-08-04 | 제일모직주식회사 | Method of Preparing Rubber Modified Polystyrene Resin Composition With High Gloss and Impact Resistance |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS51139850A (en) * | 1975-05-15 | 1976-12-02 | Labofina Sa | High impact polystylene composition and process for production thereof |
| US4493922A (en) * | 1980-09-20 | 1985-01-15 | Basf Aktiengesellschaft | Impact-resistant thermoplastic molding material |
| JPH0463099A (en) * | 1990-06-29 | 1992-02-28 | Kyocera Corp | Piezoelectric sounding body with coil and manufacture thereof |
-
1988
- 1988-04-11 JP JP63087305A patent/JPH01261444A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS51139850A (en) * | 1975-05-15 | 1976-12-02 | Labofina Sa | High impact polystylene composition and process for production thereof |
| US4493922A (en) * | 1980-09-20 | 1985-01-15 | Basf Aktiengesellschaft | Impact-resistant thermoplastic molding material |
| JPH0463099A (en) * | 1990-06-29 | 1992-02-28 | Kyocera Corp | Piezoelectric sounding body with coil and manufacture thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01261444A (en) | 1989-10-18 |
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