JPH0463099B2 - - Google Patents
Info
- Publication number
- JPH0463099B2 JPH0463099B2 JP61255835A JP25583586A JPH0463099B2 JP H0463099 B2 JPH0463099 B2 JP H0463099B2 JP 61255835 A JP61255835 A JP 61255835A JP 25583586 A JP25583586 A JP 25583586A JP H0463099 B2 JPH0463099 B2 JP H0463099B2
- Authority
- JP
- Japan
- Prior art keywords
- rubber
- modified polystyrene
- microns
- weight
- gloss
- 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 74
- 239000004793 Polystyrene Substances 0.000 claims description 46
- 229920002223 polystyrene Polymers 0.000 claims description 46
- 229920001971 elastomer Polymers 0.000 claims description 32
- 239000005060 rubber Substances 0.000 claims description 29
- -1 polydimethylsiloxane Polymers 0.000 claims description 22
- 239000004205 dimethyl polysiloxane Substances 0.000 claims description 19
- 239000000203 mixture Substances 0.000 claims description 19
- 229920000435 poly(dimethylsiloxane) Polymers 0.000 claims description 19
- 239000011342 resin composition Substances 0.000 claims description 16
- 241001237745 Salamis Species 0.000 claims description 8
- 235000015175 salami Nutrition 0.000 claims description 8
- 229920005990 polystyrene resin Polymers 0.000 claims description 6
- 238000009826 distribution Methods 0.000 claims description 4
- 229920000642 polymer Polymers 0.000 claims description 3
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 16
- 229920002857 polybutadiene Polymers 0.000 description 11
- 229920005989 resin Polymers 0.000 description 11
- 239000011347 resin Substances 0.000 description 11
- 239000005062 Polybutadiene Substances 0.000 description 10
- 230000007423 decrease Effects 0.000 description 9
- 238000003756 stirring Methods 0.000 description 8
- 238000002156 mixing Methods 0.000 description 6
- 238000000034 method Methods 0.000 description 5
- 238000006116 polymerization reaction Methods 0.000 description 5
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 229920005669 high impact polystyrene Polymers 0.000 description 4
- 239000004797 high-impact polystyrene Substances 0.000 description 4
- 230000000379 polymerizing effect Effects 0.000 description 4
- 229920000122 acrylonitrile butadiene styrene Polymers 0.000 description 3
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- 239000000314 lubricant Substances 0.000 description 3
- 230000000704 physical effect Effects 0.000 description 3
- 229920001296 polysiloxane Polymers 0.000 description 3
- 125000003118 aryl group Chemical group 0.000 description 2
- 238000004040 coloring Methods 0.000 description 2
- 235000014113 dietary fatty acids Nutrition 0.000 description 2
- 239000000975 dye Substances 0.000 description 2
- 238000001125 extrusion Methods 0.000 description 2
- 239000000194 fatty acid Substances 0.000 description 2
- 229930195729 fatty acid Natural products 0.000 description 2
- 150000004665 fatty acids Chemical class 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000178 monomer Substances 0.000 description 2
- 239000008188 pellet Substances 0.000 description 2
- 239000000049 pigment Substances 0.000 description 2
- 239000004033 plastic Substances 0.000 description 2
- 229920003023 plastic Polymers 0.000 description 2
- 229920003048 styrene butadiene rubber Polymers 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
- 239000005064 Low cis polybutadiene Substances 0.000 description 1
- 229920001890 Novodur Polymers 0.000 description 1
- 238000003917 TEM image Methods 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 150000001408 amides Chemical class 0.000 description 1
- 239000002216 antistatic agent Substances 0.000 description 1
- 238000005452 bending Methods 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
- 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
- 230000001413 cellular effect Effects 0.000 description 1
- 235000019646 color tone Nutrition 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 239000000945 filler Substances 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
- 238000000465 moulding Methods 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
- 239000004014 plasticizer Substances 0.000 description 1
- 229920005604 random copolymer Polymers 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000000126 substance 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
Landscapes
- Compositions Of Macromolecular Compounds (AREA)
Description
（産業上の利用分野）
本発明は、優れた品質総合のバランスを有する
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
の部品など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いが及ばないという欠
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、着色性、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、コストダウンを計れる経済的な樹脂
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
光沢を向上させる為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。また衝撃強
度と光沢のバランスを改良する為に1.0ミクロン
以下の小さなゴム粒子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
チレンとのプレンドからなる組成物が特公昭46−
41467号公報、特開昭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号明細書などの先行文献
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為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
の問題点があつた。
また、ゴム変性スチレン系樹脂と有機ポリシロ
キサンからなる樹脂組成物はModern Plastics
1972年11月号114〜116ページ、プラスチツクス・
エージ1974年20巻５月号107ページ、特開昭55−
3494号公報、特開昭53−124561号公報、特開昭57
−187345号公報、特開昭57−187346号公報などの
先行文献に述べられているが、ゴム粒子径の小さ
いゴム変性ポリスチレンを用いた場合には好まし
い樹脂組成物が得られていない。
（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
光沢勾配の少いこと）、着色性、衝撃強度、剛性
の品質バランスのよいゴム変性ポリスチレン樹脂
が必要となる。上記する優れた成形品外観、着色
性、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得ることが本発明
の目的である。
（問題点を解決するための手段）
本発明の組成物は、特定のミクロ構造を有する
ゴム変性ポリスチレンとポリジメチルシロキサン
よりなる。
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
分散粒子は単一オクルージヨン構造の小粒子部分
とサラミ構造の大粒子部分との２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、大粒子部分の平均粒子径が0.7
〜2.0ミクロンにあることを特徴とするゴム変性
ポリスチレンからなる樹脂組成物である。
有機ポリシロキサンのなかのポリジメチルシロ
キサンと上記に述べた特定のミクロ構造を有する
ゴム変性ポリスチレンとを組み合せることによつ
て驚くべきことに非常に品質総合バランスが優れ
た耐衝撃性ポリスチレン樹脂組成物を得ることに
成功したものである。
本発明で用いる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ピニル単量体を重
合せしめる塊状重合法又は塊状懸濁重合法にて製
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。
また、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、シス含有量の低いローシスポリ
ブタジエンとも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２つの山か
らなる分布を示す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つく
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、また0.6ミクロン
を越えると成型品の外観、特に光沢勾配が大きく
なりまた光沢の低下がみられ好ましくない。更に
小粒子ゴムは単一オクルージヨン構造（シエル／
コア形ともいわれる）を有していることが、光沢
と耐衝撃強度のバランスを良好ならしめるために
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良く製
造することができる。なお大粒子ゴムは従来のゴ
ム変性ポリスチレンに見られるサラミ構造（セル
状または細胞状ともいわれる）を有するものであ
る。このような大粒子ゴムは、公知の方法に従
い、ポリブタジエンゴムやスチレンとブタジエン
のランダム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容易に製造することが出
来る。また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、また2.0ミクロン
を越えると成型品の外観、特に光沢勾配が大きく
なり、また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。また
ゴム粒子径分布は小粒子部分と大粒子部分からな
る２つの山からなる分布を有していることが成型
品外観、衝撃強度、着色性、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
を測定して次式により算出したものである。
平均粒子径＝ΣniDi4／ΣniDi3
（ここにniは粒子径Diのゴム状重合体粒子の個
数である。）
また本発明において、組成物中のゴムの総量の
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
％を越えると衝撃強度が低下し好ましくない。
また、本発明の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為に、実質上２ミクロン
を越える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
を越える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ミクロンを越える大きなゴム
粒子が20重量％以上存在すると光沢勾配が大きく
なり、また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。
本発明で用いるポリジメチルシロキサンは
(Industrial Application Field) The present invention relates to a high-impact polystyrene resin composition having an excellent overall quality balance. For example, rubber-modified polystyrene is often used in parts of home appliances, but conventionally 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, colorability, impact strength, and rigidity in injection molded products, extrusion sheets, extrusion vacuum molding, and the like. It has great value as an economical resin that can replace expensive ABS resin, make products thinner, and reduce costs. (Prior art) Rubber-modified polystyrene has been widely used industrially, but its dispersed rubber particle size is generally about 1.0 to 5.0 microns, and recently rubber-modified polystyrene has been used to improve the gloss of molded products. Although rubber particles with small diameters have been developed and put on the market, a desirable resin has not yet been obtained in which the impact strength significantly decreases when the rubber particle diameter is as small as 1.0 microns or less. In addition, in order to improve the balance between impact strength and gloss, a composition consisting of a blend of rubber-modified polystyrene with small rubber particles of 1.0 microns or less and rubber-modified polystyrene with a large rubber particle size was developed.
Although it is described in prior documents such as JP 41467, JP 59-1519, US Patent No. 4146589, US Patent No. 4214056, and US Patent No. 4493922, it has not been used. There are 2 large particles
Because it is larger than microns, the appearance of the molded product is inferior.
In particular, there were problems such as a large gloss gradient (a large drop in gloss at parts far from the gate in the molded product) and insufficient gloss when molded at low mold temperatures. In addition, a resin composition consisting of a rubber-modified styrenic resin and an organic polysiloxane is manufactured by Modern Plastics.
November 1972 issue, pages 114-116, Plastics.
Age 1974 Vol. 20 May issue page 107, 1974-
Publication No. 3494, Japanese Unexamined Patent Publication No. 124561/1983, Japanese Patent Unexamined Publication No. 1983-124561
Although described in prior documents such as JP-A-187345 and JP-A-57-187346, a preferred resin composition has not been obtained when rubber-modified polystyrene having a small rubber particle size is used. (Problems to be Solved by the Invention) In order to meet the market demand for rubber-modified polystyrene with an excellent overall balance of quality as described above, it is necessary to have an excellent molded product appearance (in particular, a high gloss value and a low gloss gradient). A rubber-modified polystyrene resin with a good balance of colorability, impact strength, and rigidity is required. It is an object of the present invention to obtain an inexpensive impact-resistant polystyrene resin having an excellent quality balance among the above-mentioned excellent molded product appearance, colorability, impact strength, and rigidity. (Means for Solving the Problems) The composition of the present invention consists of rubber-modified polystyrene and polydimethylsiloxane having a specific microstructure. That is, the present invention provides an impact-resistant polystyrene resin composition in which a rubber-like polymer is dispersed in the form of particles in rubber-modified polystyrene in the composition, and the dispersed particles have a small particle portion with a single occlusion structure. It shows a distribution consisting of two peaks, the large particle part and the salami structure, and the average particle diameter of the small particle part is 0.1 to 0.6.
micron, and the average particle diameter of the large particle part is 0.7
This is a resin composition made of rubber-modified polystyrene characterized by a particle size of ~2.0 microns. By combining polydimethylsiloxane, which is an organic polysiloxane, and rubber-modified polystyrene having the specific microstructure described above, an impact-resistant polystyrene resin composition surprisingly has an excellent overall quality balance. It was successfully obtained. The rubber-modified polystyrene used in the present invention can be produced by a bulk polymerization method or a bulk suspension polymerization method in which an aromatic monopynyl 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. Examples of aromatic monovinyl monomers include styrene and nuclear alkyl-substituted styrenes such as o-methylstyrene, p-methylstyrene, m-methylstyrene, 2,4-dimethylstyrene, ethylstyrene, and p-tert-butylstyrene; α-alkyl substituted styrenes such as -methylstyrene and α-methyl-p-methylstyrene are used. Further, examples of the rubbery polymer include polybutadiene, styrene-butadiene copolymer, etc., and as the polybutadiene, both high-cis polybutadiene with a high cis content and low-cis polybutadiene with a low cis content can be used. In the present invention, modified polystyrene having a rubber particle size distribution consisting of two peaks 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 be produced by blending or by mixing small particle rubber and large particle rubber in a polymerization reactor. The average particle size of the small particle portion must be 0.1 to 0.6 microns, preferably 0.2 to 0.6 microns.
It is 0.5 micron. If the average particle diameter 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, and the gloss will decrease, which is undesirable. Furthermore, small particle rubber has a single occlusion structure (shell/
It is necessary to have a core shape (also called a core shape) in order to achieve a good balance between gloss and impact strength. Such small particle rubber can be efficiently produced by polymerizing styrene under stirring in the presence of a block copolymer of styrene and butadiene. The large particle rubber has a salami structure (also called cellular or cell-like) that is found in conventional rubber-modified polystyrene. Such large particle rubber can be easily produced by polymerizing styrene under stirring in the presence of polybutadiene rubber or a random copolymer of styrene and butadiene, according to a known method. In addition, the average particle diameter of the large particle portion must be 0.7 to 2.0 microns, preferably 1.0 to 2.0 microns.
It is 1.5 microns. 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 low mold temperatures, the gloss may be insufficient. It is unfavorable in that it becomes In addition, the rubber particle size distribution has two peaks 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, colorability, 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. be. Average particle diameter = ΣniDi 4 /ΣniDi 3 (here, ni is the number of rubbery polymer particles with a particle diameter Di).
20-95% by weight, preferably 50-90%, most preferably 60-80% by weight are small particle fractions, and 5-95% by weight are small particle fractions.
80% 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 deteriorates, and if it exceeds 95% by weight, the impact strength decreases, which is not preferred. Furthermore, 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 exceeding 2 microns. Substantially free means that rubber particles larger than 2 microns account for less than 20% by weight, preferably less than 5% by weight of the total amount of rubber in the composition. If 20% by weight or more of large rubber particles exceeding 2 microns are present in the composition, the gloss gradient becomes large, and the gloss of molded products obtained at low mold temperatures decreases, making it difficult to obtain a desirable molded product appearance. I can't. The polydimethylsiloxane used in the present invention is
【式】で表わされる構造単位を有して
いることが必要である。本発明のようなゴム粒子
径を有するゴム変性ポリスチレンの場合には、ポ
リジメチルシロキサン以外の先行技術文献に述べ
られているような有機ポリシロキサンでは好まし
い樹脂組成物が得られない。更に好ましくは、ポ
リジメチルシロキサンの粘度も25℃で、10〜
10000センチストークスと比較的分子量の低い範
囲にあることである。
更に耐衝撃性ポリスチレン組成物中のポリジメ
チルシロキサンの含有量は、0.005〜0.8重量％の
範囲にあることである。含有量が0.005重量％未
満となると衝撃強度の低下が見られ、0.8重量％
を越えると、着色性および樹脂成形品の二次加工
性（化学接着性、印刷性、塗装性等）の点で好ま
しくない。添加量が多くなつた場合、着色性及び
二次加工性が悪化する理由は定かでないがゴム変
性ポリスチレン中へのポリジメチルシロキサンの
相溶性が低下する為ではないかと考えられる。
このような点から、ポリジメチルシロキサンの
含有量が好ましい耐衝撃性ポリスチレン組成物を
得るために重要である。
本発明の耐衝撃性ポリスチレン組成物を製造す
る方法は、特に限定されることはなく、例えばス
チレンモノマーにポリジメチルシロキサンを添加
して重合を行なつてもよいし、ゴム変性ポリスチ
レンとポリジメチルシロキサンを押出機等を用い
て溶融混合を行なつてもよい。更にはポリジメチ
ルシロキサンとポリスチレンからポリジメチルシ
ロキサン濃度の高いマスターペレツトを製造し、
そのマスターペレツトとゴム変性ポリスチレンを
混合し成形物を得てもよい。
本発明の耐衝撃性ポリスチレン組成物には高級
脂肪酸の金属塩、たとえばステアリン酸亜鉛、ス
テアリン酸カルシウムなど高級脂肪酸のアミド
類、たとえばエチレンビスステアロアミドなど、
の滑剤を組み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。
また、本発明の耐衝撃性ポリスチレン組成物に
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。
（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。特に、特
殊なミクロ構造を有するゴム変性ポリスチレンと
ポリジメチルシロキサンとの組み合せにて得た樹
脂組成物は、従来のゴム変性ポリスチレンに比べ
て耐衝撃強度が大巾に向上し、かつ成形品外観、
特に射出成形された成形品においてゲート部分か
ら遠く離れた部分の光沢が非常に良好である。こ
のような特性を有することから特に大型の射出成
形品を得る為の樹脂として非常に好ましい。更に
着色性が良好であることは、着色時に使用する染
顔料コストが大巾に安くなり工業的に非常に大き
な意味を持つでのある。
本発明の樹脂は、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。特に鮮やかな色調
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。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 D790光沢；
ASTM D638のダンベル試験片のゲートとエン
ドゲート部の光沢度を測定した。
実施例１〜５及び比較例１〜５
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0.3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1.2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
あるゴム変性ポリスチレンＢとを表−１に示した
比率で混合し、更にゴム変性ポリスチレン100重
量部に対し500センチストークスの粘度を有する
ポリジメチルシロキサン0.05重量部を表−１に示
す如く加え押出機にて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、曲げ弾性率及び着色性を評価した。その結果
を表−１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してポリジメチ
ルシロキサンを加え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
単独の場合にはポリジメチルシロキサンを加えて
も衝撃強度のすぐれた組成物は得られない。
比較例 ６
ポリブタジエンの存在下にスチレンモノマーを
撹拌下に重合し、平均粒子径が0.4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
調整した。かくして得たゴム変性ポリスチレンを
実施例３におけるゴム変性ポリスチレンＡに変え
て樹脂組成物を得、物性を評価した。結果を表−
１に示す。
小粒子ゴムの構造がサラミ構造の場合には、光
沢及び光沢勾配が劣る。
実施例６及び比較例７〜10
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、2.7ミクロン、5.2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B25重量％と実施例１〜５で用いたゴム変性
ポリスチレンA75重量％と、更にゴム変性ポリス
チレン100重量部に対し500センチストークスの粘
度を有するポリジメチルシロキサン0.05重量部を
表−２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。
その結果を表−２に示す。ゴム変性ポリスチレ
ンＡと組み合せるゴム変性ポリスチレンの平均粒
子径が２ミクロンを越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。また平均粒径が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 11
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0.7μ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。その結果を表−２に示す。光沢勾配が大
きくなり好ましくない。It is necessary to have a structural unit represented by the formula: In the case of rubber-modified polystyrene having the rubber particle size of the present invention, a preferred resin composition cannot be obtained with organic polysiloxanes such as those described in prior art documents other than polydimethylsiloxane. More preferably, the viscosity of the polydimethylsiloxane is also 10 to 10 at 25°C.
It has a relatively low molecular weight of 10,000 centistokes. Furthermore, the content of polydimethylsiloxane in the impact-resistant polystyrene composition is in the range of 0.005 to 0.8% by weight. When the content is less than 0.005% by weight, a decrease in impact strength is observed, and 0.8% by weight.
If it exceeds this range, it is unfavorable in terms of colorability and secondary processability (chemical adhesion, printability, paintability, etc.) of the resin molded product. It is not clear why the colorability and secondary processability deteriorate when the amount added is large, but it is thought that it is because the compatibility of polydimethylsiloxane in rubber-modified polystyrene decreases. From this point of view, the content of polydimethylsiloxane is important for obtaining a preferred high impact polystyrene composition. The method for producing the high-impact polystyrene composition of the present invention is not particularly limited, and for example, polymerization may be carried out by adding polydimethylsiloxane to styrene monomer, or polymerization may be carried out by adding polydimethylsiloxane to styrene monomer, or by polymerizing rubber-modified polystyrene and polydimethylsiloxane. Melt mixing may be performed using an extruder or the like. Furthermore, master pellets with a high concentration of polydimethylsiloxane are manufactured from polydimethylsiloxane and polystyrene,
A molded product may be obtained by mixing the master pellets with rubber-modified polystyrene. The high-impact polystyrene composition of the present invention includes metal salts of higher fatty acids, such as zinc stearate, calcium stearate, and amides of higher fatty acids, such as ethylene bisstearamide.
By using a combination of these lubricants, favorable results are obtained 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. Furthermore, additives such as dyes and pigments, lubricants, fillers, mold release agents, plasticizers, and antistatic agents can be added to the impact-resistant polystyrene composition of the present invention, if necessary. (Effects) 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. In particular, resin compositions obtained by combining rubber-modified polystyrene with a special microstructure and polydimethylsiloxane have greatly improved impact resistance strength compared to conventional rubber-modified polystyrene, and have improved appearance of molded products.
Particularly in injection molded products, the gloss of the parts far away from the gate part is very good. Because it has such characteristics, it is very preferable as a resin particularly for obtaining large injection molded products. Furthermore, good coloring property means that the cost of dyes and pigments used for coloring can be greatly reduced, which is of great industrial significance. The resin of the present invention can be used as molded products in fields such as light electrical equipment and miscellaneous goods. Particularly favorable results can be obtained in molded products that require vivid color tones. (Example) Examples are shown below. The data shown in the examples were measured based on the following method. Izot impact strength: Based on ASTM D256. Bending strength, flexural modulus; ASTM D790 gloss;
The glossiness of the gate and end gate portions of ASTM D638 dumbbell specimens was measured. Examples 1 to 5 and Comparative Examples 1 to 5 Polymerization of styrene monomer with stirring in the presence of a styrene-butadiene block copolymer had an average particle diameter of 0.3 microns and a single occlusion structure. , obtained by polymerizing rubber-modified polystyrene A with a polybutadiene component content of 9% by weight and styrene monomer in the presence of polybutadiene under stirring, with an average particle diameter of 1.2 microns and a salami structure. and rubber-modified polystyrene B having a polybutadiene component content of 12% by weight in the resin at the ratio shown in Table 1. 0.05 parts by weight of polydimethylsiloxane was added as shown in Table 1 and melt-kneaded using an extruder to obtain a resin composition. The gloss, Izot impact strength, flexural modulus, and colorability of the resin composition were evaluated. The results are shown in Table-1. By blending rubber-modified polystyrene A containing small-diameter rubber particles and rubber-modified polystyrene B containing large-particle rubber particles in an appropriate ratio and adding polydimethylsiloxane, gloss, especially the gloss of the end gate area, can be improved. Compositions with good values and extremely high impact strength are obtained. Rubber modified polystyrene A
When used alone, even if polydimethylsiloxane is added, a composition with excellent impact strength cannot be obtained. Comparative Example 6 Styrene monomer was polymerized with stirring in the presence of polybutadiene to prepare rubber-modified polystyrene having an average particle size of 0.4 microns, a salami structure, and a polybutadiene component content of 9% by weight in the resin. . The rubber-modified polystyrene thus obtained was replaced with rubber-modified polystyrene A in Example 3 to obtain a resin composition, and its physical properties were evaluated. Display the results -
Shown in 1. When the structure of the small particle rubber is a salami structure, the gloss and gloss gradient are poor. Example 6 and Comparative Examples 7 to 10 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 micron, 0.9 micron, Four types of rubber-modified polystyrene B having salami structures of 2.7 microns and 5.2 microns and containing 12% by weight of the polybutadiene component in the resin were obtained. 25% by weight of the rubber-modified polystyrene B obtained here, 75% by weight of the rubber-modified polystyrene A used in Examples 1 to 5, and further 0.05 parts by weight of polydimethylsiloxane having a viscosity of 500 centistokes per 100 parts by weight of the rubber-modified polystyrene. In addition, as shown in Table 2, a resin composition was obtained in the same manner as in Example 1, and its 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 rubber-modified polystyrene A exceeds 2 microns, the gloss gradient becomes large (the gloss at the end gate portion is low), resulting in unfavorable results. Furthermore, if the average particle size is as small as 0.6 microns, the impact strength decreases, which is not preferable. Comparative Example 11 In place of the rubber-modified polystyrene A in Example 3, the same procedure was carried out using rubber-modified polystyrene having an average particle diameter of 0.7μ, a salami structure, and a polybutadiene component content of 9% by weight in the resin. I conducted an evaluation. The results are shown in Table-2. The gloss gradient becomes large, which is not preferable.
【表】【table】
【表】【table】
Claims (1)
状重合体が粒子状に分散しており、その分散粒
子は単一オクルージヨン構造の小粒子部分とサ
ラミ構造の大粒子部分との２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、大粒子部分の平均粒子径が
0.7〜2.0ミクロンであり、 (B) 該組成物中にポリジメチルシロキサンが
0.005〜0.8重量％含有されている事を特徴とす
る高光沢耐衝撃性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
ことを特徴とす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
であることを特徴とする特許請求の範囲第１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
であることを特徴とする特許請求の範囲第１項記
載の組成物。[Scope of Claims] 1. In an impact-resistant polystyrene resin composition, (A) a rubber-like polymer is dispersed in the form of particles in rubber-modified polystyrene in the composition, and the dispersed particles have a single occlusion structure. It shows a distribution consisting of two peaks, a small particle part and a large particle part with a salami structure, and the average particle diameter of the small particle part is 0.1 to 0.6.
microns, and the average particle size of the large particles is
0.7 to 2.0 microns, and (B) polydimethylsiloxane is present in the composition.
A high-gloss impact-resistant polystyrene resin composition characterized by containing 0.005 to 0.8% by weight. 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, wherein the average particle diameter of the small particle portion is 0.2 to 0.5 microns. 4. The composition according to claim 1, wherein the average particle diameter of the large particle portion is 1.0 to 1.5 microns.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25583586A JPS63112646A (en) | 1986-10-29 | 1986-10-29 | High-gloss, impact-resistant 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 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25583586A JPS63112646A (en) | 1986-10-29 | 1986-10-29 | High-gloss, impact-resistant polystyrene resin composition |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63112646A JPS63112646A (en) | 1988-05-17 |
| JPH0463099B2 true JPH0463099B2 (en) | 1992-10-08 |
Family
ID=17284259
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25583586A Granted JPS63112646A (en) | 1986-10-29 | 1986-10-29 | High-gloss, impact-resistant polystyrene resin composition |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63112646A (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2676261B2 (en) * | 1988-07-28 | 1997-11-12 | 出光石油化学 株式会社 | Rubber modified styrenic resin composition |
| JPH0238435A (en) * | 1988-07-28 | 1990-02-07 | Idemitsu Petrochem Co Ltd | Styrene resin composition |
| 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 |
| JPH0689203B2 (en) * | 1989-11-14 | 1994-11-09 | 出光石油化学株式会社 | Styrene resin composition |
| JPH0689202B2 (en) * | 1989-11-14 | 1994-11-09 | 出光石油化学株式会社 | Flame-retardant styrene resin composition |
| JPH0689204B2 (en) * | 1989-11-29 | 1994-11-09 | 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 |
| JP3686681B2 (en) * | 1992-03-10 | 2005-08-24 | 住友化学株式会社 | 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 |
| KR100384385B1 (en) | 1998-03-23 | 2003-08-27 | 주식회사 엘지화학 | Preparation method of rubber-modified styrene-based resin with high gloss and impact resistance |
| KR100401325B1 (en) * | 2000-12-18 | 2003-10-10 | 제일모직주식회사 | High Impact Polystyrene Resin with Good Falling Dart Impact and Anti-abrasion Prepared by Continuous Mass Polymerization Process |
| ITMI20031420A1 (en) * | 2003-07-11 | 2005-01-12 | Polimeri Europa Spa | REINFORCED VINYLAROMATIC POLYMERS WITH RUBBER |
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Also Published As
| Publication number | Publication date |
|---|---|
| JPS63112646A (en) | 1988-05-17 |
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| Date | Code | Title | Description |
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| LAPS | Cancellation because of no payment of annual fees |