JP3125418B2 - Method for producing expandable vinyl resin particles - Google Patents
Method for producing expandable vinyl resin particlesInfo
- Publication number
- JP3125418B2 JP3125418B2 JP6337992A JP6337992A JP3125418B2 JP 3125418 B2 JP3125418 B2 JP 3125418B2 JP 6337992 A JP6337992 A JP 6337992A JP 6337992 A JP6337992 A JP 6337992A JP 3125418 B2 JP3125418 B2 JP 3125418B2
- Authority
- JP
- Japan
- Prior art keywords
- polymerization
- weight
- resin particles
- particles
- vinyl resin
- 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.)
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- Processes Of Treating Macromolecular Substances (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
- Polymerisation Methods In General (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Description
【0001】[0001]
【産業上の利用分野】本発明は、スチレンに代表される
ビニル系単量体の懸濁重合により、粒径分布の狭いビニ
ル系樹脂粒子を製造する方法であって、粒子内に気泡が
なく、偏平粒子の生成しない発泡性ビニル系樹脂粒子の
製造法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing vinyl resin particles having a narrow particle size distribution by suspension polymerization of a vinyl monomer represented by styrene. And a method for producing expandable vinyl resin particles that do not produce flat particles.
【0002】[0002]
【従来の技術】一般に懸濁重合によって生成されるビニ
ル系樹脂は、撹拌と懸濁剤(分散剤)の働きによって水
中に分散され粒子状で生成される。懸濁剤はビニル系単
量体または単量体と重合体の混合物、すなわち油系粒子
が合一して塊状となるのを防止する働きをもつ。樹脂粒
子は、一般に用途によって、粒径の均一化が求められ
る。例えば、発泡性スチレン系樹脂粒子は、次の3つの
分野に分けられる。すなわち、(1)粒子径約300μ
m〜700μmの発泡性スチレン系樹脂粒子はインスタ
ント食品等のカップ用、(2)粒子径約700μm〜1
800μmの粒子径のものは各種の梱包用および魚箱
用、(3)粒子径約1300μm〜3000μmのもの
は、建材用、ボード等に使用される。これらの用途の違
いから、要求される発泡性スチレン系樹脂粒子の性質も
異なるので、用途別に発泡性スチレン系樹脂粒子を製造
する必要に迫られるが、懸濁重合で得られた樹脂粒子の
粒子径分布が広いとその目的を達し難い。2. Description of the Related Art In general, vinyl resins produced by suspension polymerization are dispersed in water by the action of stirring and a suspending agent (dispersant) to be produced in the form of particles. The suspending agent has a function of preventing the vinyl-based monomer or the mixture of the monomer and the polymer, that is, the oil-based particles from being united and formed into a mass. Resin particles are generally required to have a uniform particle size depending on the application. For example, expandable styrene resin particles are divided into the following three fields. That is, (1) a particle diameter of about 300 μm
Expandable styrene resin particles of m to 700 μm are used for cups of instant foods, etc. (2) Particle diameter of about 700 μm to 1
Those having a particle diameter of 800 μm are used for various packing and fish boxes, and (3) those having a particle diameter of about 1300 μm to 3000 μm are used for building materials, boards and the like. Due to the difference in these uses, the properties of the expandable styrene resin particles required are also different, so it is necessary to produce expandable styrene resin particles for each application, but the resin particles obtained by suspension polymerization are required. If the diameter distribution is wide, it is difficult to achieve its purpose.
【0003】従来から、スチレン等のビニル系単量体の
懸濁重合に用いられる懸濁剤には主懸濁剤としては、難
溶性リン酸塩、懸濁助剤としては陰イオン界面活性剤な
どが用いられることが公知である。具体的にはリン酸三
カルシウムとドデシルベンゼンスルフォン酸ナトリウム
が最も一般的な懸濁剤である。この懸濁剤を用いての懸
濁重合によって生成される樹脂粒子の粒子径は約0.1
〜3mmの範囲にあり、粒子径分布は幅広いものであっ
た。従来、樹脂粒子の粒子径は懸濁剤濃度及び撹拌効果
等の機械的要因等によって任意にコントロールすること
は可能であった。しかし、樹脂粒子の粒子径分布を狭く
することは非常に困難であった。Heretofore, a suspending agent used for suspension polymerization of vinyl monomers such as styrene has been a poorly soluble phosphate as a main suspending agent, and an anionic surfactant as a suspending aid. It is known that such is used. Specifically, tricalcium phosphate and sodium dodecylbenzene sulfonate are the most common suspending agents. The particle size of the resin particles produced by suspension polymerization using this suspending agent is about 0.1
33 mm, and the particle size distribution was broad. Conventionally, the particle diameter of the resin particles can be arbitrarily controlled by mechanical factors such as the concentration of the suspending agent and the stirring effect. However, it was very difficult to narrow the particle size distribution of the resin particles.
【0004】[0004]
【発明が解決しようとする課題】特公昭63−1248
1号公報に記載される方法は、これらの課題に対し解決
する方法を提供しており、所望の粒子径の球状粒子を高
収率で得ることができ、経済的に非常に有利である。し
かし、この方法で得られたスチレン系樹脂を含む懸濁系
に、常温で気体または液体の液化石油ガス、具体的には
プロパン、ブタン、ペンタン、ヘキサン等の脂肪族炭化
水素の1種又は2種以上の混合物を含浸させて得られる
発泡性スチレン系樹脂粒子中には、楕円状の粒子(30
0〜600μm、以下偏平粒子と呼ぶ)が多量に含ま
れ、これらは篩分けによっては、分離不能のため、一部
の製品中に混入し著しく商品価値を低下させていた。こ
れら偏平粒子が製品中に含まれると1次発泡(予備発
泡)した際に、ブロッキングが発生する。予備発泡中に
ブロッキングすると、予備発泡機の篩が目詰りし、発泡
粒を熟成サイロに送ることが困難となる。またブロッキ
ングが多いと発泡機内の槽壁に発泡粒が付着し、発泡倍
数のばらつきの原因となったり、成形機に送る配管内が
ブロッキング物で詰まり充てん不良の原因となったりす
る。さらに球状の正常な発泡粒と同時にこの偏平粒子が
成形されると成形品の外観が著しく低下する。本発明
は、かかる欠点を解決したものである。[Problems to be Solved by the Invention] JP-B-63-1248
The method disclosed in Japanese Patent Publication No. 1-2005-179 provides a method for solving these problems, and spherical particles having a desired particle diameter can be obtained in a high yield, which is very economically advantageous. However, a liquefied petroleum gas which is gaseous or liquid at room temperature, specifically one or two or more aliphatic hydrocarbons such as propane, butane, pentane and hexane is added to the suspension containing the styrene resin obtained by this method. Among the expandable styrene resin particles obtained by impregnating a mixture of at least two kinds of particles, elliptical particles (30
0 to 600 μm, hereinafter referred to as flat particles), which cannot be separated by sieving, and were mixed into some products to significantly lower the commercial value. When these flat particles are contained in a product, blocking occurs at the time of primary foaming (preliminary foaming). If blocking is performed during the prefoaming, the sieve of the prefoaming machine becomes clogged, and it becomes difficult to send the expanded granules to the aging silo. Also, if there is a lot of blocking, the foam particles adhere to the tank wall in the foaming machine, causing a variation in the number of times of foaming, and the inside of the pipe sent to the molding machine is blocked with a blocking substance, thereby causing poor filling. Furthermore, when the flat particles are molded simultaneously with the normal spherical expanded particles, the appearance of the molded product is significantly reduced. The present invention has solved such a drawback.
【0005】[0005]
【課題を解決するための手段】すなわち、本発明は、難
溶性リン酸塩及び陰イオン界面活性剤の存在下に、ビニ
ル系単量体を懸濁重合するに際し、水溶性亜硫酸塩又は
その前駆物質を、重合開始前又は重合率30重量%以下
の段階で加え、その後でかつ重合率が20〜60重量%
の間に難溶性リン酸塩を1回以上添加し、さらに難溶性
リン酸塩の添加後であって重合率50〜70重量%の間
に過酸化水素を添加して重合を行い、重合途中又は重合
後に発泡剤を含浸せしめることを特徴とする発泡性ビニ
ル系樹脂粒子の製造法に関する。That is, the present invention relates to a method for preparing a water-soluble sulfite or a precursor thereof in suspension polymerization of a vinyl monomer in the presence of a sparingly soluble phosphate and an anionic surfactant. The substance is added before the start of the polymerization or at the stage of the conversion of 30% by weight or less, and thereafter, the conversion is 20 to 60% by weight.
During the polymerization, the hardly soluble phosphate is added once or more, and after the addition of the hardly soluble phosphate, hydrogen peroxide is added during the polymerization rate of 50 to 70% by weight to carry out the polymerization. Alternatively, the present invention relates to a method for producing expandable vinyl resin particles, which comprises impregnating a foaming agent after polymerization.
【0006】本発明におけるビニル系単量体としては、
スチレン、α−メチルスチレン、ビニルトルエン、パラ
クロルスチレン等のスチレン誘導体、アクリロニトリ
ル、メタクリロニトリル等のシアン化ビニル、アクリル
酸メチル、アクリル酸エチル、アクリル酸プロピル、ア
クリル酸ブチル等のアクリル酸エステル、同様のメタク
リル酸エステル、ビニルピリジン、ビニルカルバゾー
ル、ブタジエンなどがあるが、発泡性ビニル系樹脂粒子
としての諸特性の面から、スチレンを50重量%以上含
有するビニル系単量体が好ましい。[0006] The vinyl monomer in the present invention includes:
Styrene, α-methylstyrene, vinyltoluene, styrene derivatives such as parachlorostyrene, acrylonitrile, vinyl cyanide such as methacrylonitrile, acrylic acid esters such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, Similar methacrylic acid esters, vinyl pyridine, vinyl carbazole, butadiene and the like are available, but from the viewpoint of various properties as expandable vinyl resin particles, a vinyl monomer containing 50% by weight or more of styrene is preferable.
【0007】難溶性リン酸塩としては、リン酸三カルシ
ウム、リン酸マグネシウム等があり、サブミクロン単位
と呼ばれる0.2〜0.05μmの大きさのものが有用
である。難溶性リン酸塩の合計の使用量としては重合系
に存在する物質全量に対して0.01%重量以上が好ま
しく、上限は特別に制限はないが、1重量%を超えると
必要量を超え無駄になるため、それ以下が好ましい。特
に好ましくは、0.05〜0.5重量%として使用され
る。この量が0.01重量%未満では生成される樹脂粒
子の粒子径分布を狭くすることができない。最初に反応
系に存在させる難溶性リン酸塩の量は、上記範囲におい
て特に制限はないが、好ましくは使用される難溶性リン
酸塩の合計量の1/4〜3/4の量で使用される。[0007] Examples of poorly soluble phosphates include tricalcium phosphate and magnesium phosphate, and those having a size of 0.2 to 0.05 µm, called a submicron unit, are useful. The total amount of the sparingly soluble phosphate is preferably at least 0.01% by weight based on the total amount of the substances present in the polymerization system, and the upper limit is not particularly limited. Less than that is preferable because it is useless. Particularly preferably, it is used as 0.05 to 0.5% by weight. If the amount is less than 0.01% by weight, the particle size distribution of the produced resin particles cannot be narrowed. The amount of the hardly soluble phosphate initially present in the reaction system is not particularly limited in the above range, but is preferably used in an amount of 1/4 to 3/4 of the total amount of the hardly soluble phosphate used. Is done.
【0008】陰イオン界面活性剤は、たとえば、ドデシ
ルベンゼンスルフォン酸ナトリウム等のアルキルベンゼ
ンスルフォン酸塩、アルキル基に直接SO3Naが付加
したアルキルスルフォン酸塩、ナフタリンにSO3Na
が付加したβ−テトラヒドロナフタリンスルフォン酸
塩、N−イソプロピルシクロヘキシルアシドスルフォン
酸ナトリウム等の高級脂肪酸塩、スルホコハク酸ジ−2
−エチルヘキシルナトリウム等のジアルキルスルホコハ
ク酸塩などが使用される。これらの添加量は目的とする
粒子径、機械的条件、懸濁剤濃度等によって決定される
ものではないが、一応の目安として重合系に存在する物
質全量に対して、好ましくは0.0002〜0.02重
量%、特に好ましくは0.001〜0.01重量%の範
囲である。Anionic surfactants include, for example, alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate, alkyl sulfonates in which SO 3 Na is directly added to alkyl groups, and SO 3 Na in naphthalene.
Higher fatty acid salts such as β-tetrahydronaphthalene sulfonate, sodium N-isopropylcyclohexyl acid sulfonate, di-2 sulfosuccinate
-Dialkyl sulfosuccinates such as sodium ethylhexyl and the like are used. The amount of these additives is not determined by the intended particle size, mechanical conditions, concentration of the suspending agent, etc., but as a rough guide, the amount is preferably from 0.0002 to the total amount of the substances present in the polymerization system. 0.02% by weight, particularly preferably in the range of 0.001 to 0.01% by weight.
【0009】水溶性亜硫酸塩またはその前駆物質の存在
は目的粒子径より大きい粒子及び小さい粒子の発生量を
減少させるのに特に有効である。前駆物質としては、水
溶性のピロ亜硫酸塩、ピロ硫酸塩、亜二チオン酸塩、チ
オ硫酸塩、スルホキシル酸塩、硫酸塩等があげられる。
水溶性亜硫酸塩またはその前駆物質で特に効果の高いも
のとしては、亜硫酸ナトリウム、ピロ亜硫酸ナトリウ
ム、亜硫酸水素ナトリウム、ピロ硫酸ナトリウム、亜二
チオン酸ナトリウム、硫酸水素ナトリウム、チオ硫酸ナ
トリウム、ホルムアルデヒドナトリウムスルフォキシラ
ート、亜硫酸等が含まれる。これらの亜硫酸塩およびそ
の前駆物質は単独で用いても併用してもよい。これらの
使用量としては、上記の単量体に対し、0.0001重
量%以上、好ましくは0.0001〜0.05重量%の
範囲で使用される。0.0001重量%未満では生成さ
れる重合体粒子の粒子径分布を狭くすることはできず、
一方0.05重量%を超えて使用してもその効果の増大
はあまり期待できない。これらは、重合開始前又は重合
率30重量%以下の段階で加えることにより粒子径分布
を狭くすることができる。30重量%を超えると充分な
効果は得られない。The presence of the water-soluble sulfite or its precursor is particularly effective in reducing the amount of particles larger and smaller than the target particle size. Examples of the precursor include water-soluble pyrosulfite, pyrosulfate, dithionite, thiosulfate, sulfoxylate, sulfate and the like.
Particularly effective water-soluble sulfites or their precursors include sodium sulfite, sodium pyrosulfite, sodium hydrogen sulfite, sodium pyrosulfite, sodium dithionite, sodium hydrogen sulfate, sodium thiosulfate, and sodium formaldehyde sulfo. Xylate, sulfurous acid and the like. These sulfites and their precursors may be used alone or in combination. These are used in an amount of 0.0001% by weight or more, preferably 0.0001 to 0.05% by weight, based on the above monomers. If the content is less than 0.0001% by weight, the particle size distribution of the produced polymer particles cannot be narrowed,
On the other hand, if the content exceeds 0.05% by weight, the effect cannot be expected to increase much. These can be added before the start of polymerization or at a stage of polymerization rate of 30% by weight or less to narrow the particle size distribution. If it exceeds 30% by weight, a sufficient effect cannot be obtained.
【0010】また、重合系には水溶性高分子保護コロイ
ドとして、ポリビニルアルコール、アルキルセルロー
ス、ヒドロキシアルキルセルロース、カルボキシアルキ
ルセルロース等の水溶性セルロース誘導体、ポリアクリ
ル酸ナトリウム等を存在させるのが好ましい。これらは
一種で又は二種以上使用される。これらの使用範囲は、
重合系に存在する物質全量に対して0.0002〜0.
05重量%であるのが好ましく、特に好ましくは0.0
002〜0.005重量%の範囲である。水溶性高分子
保護コロイドを使用することにより、一層懸濁系を安定
させることができ、粒子径分布を狭くするうえで好まし
い。In the polymerization system, a water-soluble polymer derivative such as polyvinyl alcohol, alkylcellulose, hydroxyalkylcellulose, carboxyalkylcellulose and the like, and sodium polyacrylate are preferably present as a water-soluble polymer protective colloid. These may be used alone or in combination of two or more. These usage ranges are:
0.0002 to 0.1 based on the total amount of the substances present in the polymerization system.
It is preferably 0.05% by weight, particularly preferably 0.05% by weight.
002 to 0.005% by weight. The use of the water-soluble polymer protective colloid is preferable in that the suspension system can be further stabilized and the particle size distribution is narrowed.
【0011】反応系に最初に存在させられる難溶性リン
酸塩、陰イオン界面活性剤および亜硫酸塩またはその前
駆物質の量は得られるスチレン系重合体粒子に対して重
要な因子となるが、その量は上記範囲内において目的と
するスチレン系重合体粒子の粒径によって適宜決定され
る。たとえば目的とする粒径を大きくするためには、最
初に反応系に存在させる難溶性リン酸塩の量を少なくす
るか、陰イオン界面活性剤の量を多くする。目的とする
粒径を小さくするためには、その逆にすればよい。The amount of the poorly soluble phosphate, anionic surfactant and sulfite or its precursor initially present in the reaction system is an important factor for the obtained styrenic polymer particles. The amount is appropriately determined according to the particle size of the target styrene-based polymer particles within the above range. For example, in order to increase the target particle size, first, the amount of the hardly soluble phosphate to be present in the reaction system is reduced, or the amount of the anionic surfactant is increased. In order to reduce the target particle size, the opposite may be performed.
【0012】本発明では、重合反応途中で難溶性リン酸
塩を、1回または2回以上に分割して添加する。添加時
期は亜硫酸塩またはその前駆物質の添加後で、重合率2
0〜60重量%の間とされる。これは、ビニル系樹脂粒
子の最終的な粒子径がこの時期に決定されるため、難溶
性リン酸塩を添加することにより目的の粒子径以上に粒
子が成長しないようにするためである。添加時期がこの
時期でないと、前記効果がない。In the present invention, the sparingly soluble phosphate is added once or in two or more portions during the polymerization reaction. The time of addition is after the addition of the sulfite or its precursor, and the polymerization rate is 2
It is between 0 and 60% by weight. This is because the final particle size of the vinyl-based resin particles is determined at this time, so that the addition of the sparingly soluble phosphate prevents the particles from growing beyond the target particle size. If the addition time is not this time, the above-mentioned effect is not obtained.
【0013】次いで、本発明においては過酸化水素を添
加する。使用される過酸化水素は、亜硫酸塩またはその
前駆物質の添加量に対し、当量比で0.8以上であるの
が好ましく、特に好ましくは0.8〜1.5である。当
量比0.8未満では、偏平粒子が発生しやすく、1.5
を超えるとその効果がそれ以上に向上しにくく無駄であ
る。またその添加時期は、重合率50〜70重量%の時
であり、好ましくは、55〜65重量%であり、特に好
ましくは最終的な粒子径が決定された重合率が約60重
量%の時である。添加時期が重合率50重量%より前で
あると粒子径分布が広くなり、70重量%を超えては偏
平粒子が発生する。Next, in the present invention, hydrogen peroxide is added. The amount of hydrogen peroxide to be used is preferably 0.8 or more, more preferably 0.8 to 1.5, in terms of equivalent ratio with respect to the amount of sulfite or a precursor thereof. If the equivalent ratio is less than 0.8, flat particles are likely to be generated,
When the value exceeds, it is difficult to further improve the effect, and it is useless. The addition time is when the degree of polymerization is 50 to 70% by weight, preferably 55 to 65% by weight, and particularly preferably when the degree of polymerization in which the final particle size is determined is about 60% by weight. It is. If the addition time is before the polymerization rate of 50% by weight, the particle size distribution becomes wide, and if it exceeds 70% by weight, flat particles are generated.
【0014】本発明において、重合に使用する重合開始
剤としては、過酸化ベンゾイル、過安息香酸ブチル等の
有機過酸化物、アゾビスイソブチロニトリル等のアゾ化
合物など一般にビニル系単量体のラジカル重合に用いら
れている重合開始剤が挙げられる。重合開始剤はビニル
系単量体に対して0.05〜1重量%使用されるのが好
ましく、重合系にはビニル系単量体に溶解して添加させ
るのが好ましい。In the present invention, the polymerization initiator used in the polymerization is generally a vinyl monomer such as an organic peroxide such as benzoyl peroxide or butyl perbenzoate, or an azo compound such as azobisisobutyronitrile. The polymerization initiator used for radical polymerization is mentioned. The polymerization initiator is preferably used in an amount of 0.05 to 1% by weight based on the vinyl monomer, and it is preferable that the polymerization initiator is dissolved in the vinyl monomer and added.
【0015】本発明における懸濁重合は50〜100
℃、好ましくは70〜98℃の温度で行なわれるのが好
ましい。また、本発明における懸濁重合において、スチ
レン系単量体と水溶性媒体の使用割合は前者/後者が重
量比で0.9/1〜1.5/1になるようにするのが好
ましい。なお、重合転化率は、たとえば、ガスクロマト
グラフ法、比重液法により測定できる。The suspension polymerization in the present invention is 50 to 100.
C., preferably at a temperature of 70 to 98.degree. Further, in the suspension polymerization in the present invention, it is preferable that the ratio of the styrene monomer to the water-soluble medium used is 0.9 / 1 to 1.5 / 1 by weight in the former / the latter. The polymerization conversion can be measured, for example, by a gas chromatography method or a specific gravity liquid method.
【0016】本発明において使用する発泡剤としては、
種々の公知のものが挙げられるが、炭素数3〜6の飽和
炭化水素、例えば、プロパン、ブタン、n−ペンタン、
i−ペンタン、ネオペンタン、n−ヘキサン、シクロヘ
キサン等を用いるのが得られる樹脂の諸特性等の面から
好ましい。添加、含浸させる量は、ビニル系樹脂粒子に
対して3〜10重量%が好ましい。添加、含浸時期は、
重合途中又は重合後のいずれでもよいが、重合率90重
量%以上の時点が好ましい。The foaming agent used in the present invention includes:
Various known ones may be mentioned, but a saturated hydrocarbon having 3 to 6 carbon atoms, for example, propane, butane, n-pentane,
It is preferable to use i-pentane, neopentane, n-hexane, cyclohexane and the like in view of various properties of the obtained resin. The amount added and impregnated is preferably 3 to 10% by weight based on the vinyl resin particles. Addition and impregnation time
Either during the polymerization or after the polymerization may be used, but a point at which the conversion is 90% by weight or more is preferable.
【0017】[0017]
【実施例】以下に本発明を実施例により詳細に説明す
る。実施例中、「部」は、「重量部」、(%)は「重量
%」を意味する。 実施例−1 3Lのオートクレーブに第3リン酸カルシウム2.0
g、ドデシルベンゼンスルフォン酸ナトリウムの1%水
溶液を4.2g、ポリビニルアルコール(ケン価度90
〜99%)の1%水溶液を0.2g、および亜硫酸ナト
リウム0.16gをイオン交換水1200gに分散およ
び溶解させた。これに過酸化ベンゾイル3gとt−ブチ
ルパーオキシベンゾエート0.5gをスチレン1000
gに溶解したものを撹拌しながら添加し、90℃に昇温
して重合を開始した。ついで重合率が30〜35重量%
(比重測定法により測定、以下同様)に達した時点で第
3リン酸カルシウムを1.1g添加し、さらに重合率が
60重量%に達したとき、過酸化水素水 (31%水溶
液)0.14gをイオン交換水10gに溶解後、添加
し、90℃で8時間重合し、重合を完結させた。その後
これに発泡剤としてブタン(n−ブタン/i−ブタン=
60〜65/40〜35)90gをN2で圧入し、11
0℃で3時間含浸し、40℃まで冷却した。オートグレ
ーブ内の余剰のブタンを放出した後、発泡性ポリスチレ
ン粒子を得た。The present invention will be described below in detail with reference to examples. In the examples, “parts” means “parts by weight” and (%) means “% by weight”. Example 1 Tricalcium phosphate 2.0 was added to a 3 L autoclave.
g, 4.2 g of a 1% aqueous solution of sodium dodecylbenzenesulfonate, polyvinyl alcohol (with a saponification degree of 90)
0.2 g of a 1% aqueous solution of -99%) and 0.16 g of sodium sulfite were dispersed and dissolved in 1200 g of ion-exchanged water. 3 g of benzoyl peroxide and 0.5 g of t-butyl peroxybenzoate were added to styrene 1000.
g was added with stirring, and the temperature was raised to 90 ° C. to initiate polymerization. Then the polymerization rate is 30-35% by weight
1.1 g of tribasic calcium phosphate was added when the concentration reached (measured by the specific gravity measurement method, the same applies hereinafter), and when the polymerization rate reached 60% by weight, 0.14 g of aqueous hydrogen peroxide (31% aqueous solution) was added. After dissolving in 10 g of ion-exchanged water, the mixture was added and polymerized at 90 ° C. for 8 hours to complete the polymerization. Then, butane (n-butane / i-butane =
The 60~65 / 40~35) 90g with pressurized N 2, 11
Impregnated at 0 ° C for 3 hours and cooled to 40 ° C. After releasing the excess butane in the autograve, expandable polystyrene particles were obtained.
【0018】実施例−2 亜硫酸ナトリウム0.16gを0.08gに、過酸化水
素水0.14gを0.07gに変更した以外は、実施例
1と同様に行い発泡性スチレン粒子を得た。 実施例−3 亜硫酸ナトリウム0.16gをチオ硫酸ナトリウム0.
12gに、過酸化水素水0.14gを0.17gに変更
した以外は、実施例1と同様に行い発泡性スチレン粒子
を得た。 実施例−4 亜硫酸ナトリウム0.16gを亜硫酸水素ナトリウム
0.2g、過酸化水素水0.14gを0.21gに変更
した以外は、実施例1と同様に行い発泡性スチレン粒子
を得た。 実施例−5 実施例−1において、過酸化水素水0.14gを0.2
1gに変更した以外は、実施例−1と同様の方法で発泡
性スチレン粒子を得た。Example 2 Expandable styrene particles were obtained in the same manner as in Example 1, except that 0.16 g of sodium sulfite was changed to 0.08 g and 0.14 g of hydrogen peroxide solution was changed to 0.07 g. Example 3 0.16 g of sodium sulfite was added to 0.1 ml of sodium thiosulfate.
Expandable styrene particles were obtained in the same manner as in Example 1, except that 0.14 g of aqueous hydrogen peroxide was changed to 0.17 g to 12 g. Example-4 Expandable styrene particles were obtained in the same manner as in Example 1, except that 0.16 g of sodium sulfite was changed to 0.2 g of sodium hydrogen sulfite and 0.14 g of aqueous hydrogen peroxide was changed to 0.21 g. Example-5 In Example-1, 0.14 g of hydrogen peroxide solution was added to 0.2%.
Except that the amount was changed to 1 g, expandable styrene particles were obtained in the same manner as in Example 1.
【0019】比較例−1 3Lのオートクレーブに第3リン酸カルシウム2.0
g、ドデシルベンゼンスルフォン酸ナトリウムの1%水
溶液4.2g、ポリビニルアルコール(ケン価度90〜
99%)の1%水溶液0.2gをイオン交換水1200
gに分散および溶解させた。これに過酸化ベンゾイル3
g、とt−ブチルパーオキシベンゾエート0.5gをス
チレン1000gに溶解したものを撹拌しながら添加
し、90℃に昇温して重合を開始した。ついで重合率が
30〜35重量%に達した時点で第3リン酸カルシウム
を1.1g添加し、そのまま、90℃で8時間重合し
た。これに発泡剤としてブタン90gをN2で圧入し、
110℃で3時間含浸し、40℃まで冷却した。オート
クレーブ内の余剰のブタンを放出した後、発泡性ポリス
チレン粒子を得た。Comparative Example 1 Tricalcium phosphate 2.0 was added to a 3 L autoclave.
g, 4.2 g of a 1% aqueous solution of sodium dodecylbenzenesulfonate, polyvinyl alcohol (with a saponification degree of 90 to 90%).
99%) of 0.2% 1% aqueous solution
g and dispersed. Benzoyl peroxide 3
g and 0.5 g of t-butyl peroxybenzoate dissolved in 1000 g of styrene were added with stirring, and the temperature was raised to 90 ° C. to initiate polymerization. Then, when the polymerization rate reached 30 to 35% by weight, 1.1 g of tricalcium phosphate was added, and polymerization was carried out at 90 ° C. for 8 hours. 90 g of butane as a blowing agent is press-fitted with N 2 ,
Impregnated at 110 ° C. for 3 hours and cooled to 40 ° C. After releasing excess butane in the autoclave, expandable polystyrene particles were obtained.
【0020】比較例−2 実施例−1において、過酸化水素水を添加しない以外
は、同様の方法で、発泡性ポリスチレン粒子を得た。 比較例−3 実施例−2において、過酸化水素水を添加しない以外
は、同様の方法で、発泡性ポリスチレン粒子を得た。 比較例−4 実施例−3において、過酸化水素水を添加しない以外
は、同様の方法で、発泡性ポリスチレン粒子を得た。 比較例−5 実施例−4において、過酸化水素水を添加しない以外
は、同様の方法で、発泡性ポリスチレン粒子を得た。Comparative Example 2 Expandable polystyrene particles were obtained in the same manner as in Example 1, except that no aqueous hydrogen peroxide was added. Comparative Example-3 Expandable polystyrene particles were obtained in the same manner as in Example-2, except that no aqueous hydrogen peroxide was added. Comparative Example-4 Expandable polystyrene particles were obtained in the same manner as in Example-3, except that no aqueous hydrogen peroxide was added. Comparative Example-5 Expandable polystyrene particles were obtained in the same manner as in Example-4, except that no aqueous hydrogen peroxide was added.
【0021】上記の各実施例および比較例で得られた発
泡性ポリスチレン粒子の粒子径分布を表1に示す。ま
た、各実施例、比較例について、Dカット品300gに
ステアリン酸亜鉛0.9gを小型リボンブレンダーで混
合した。これらの発泡性スチレン粒子を小型予備発泡機
でスチーム吹込圧1.0kg/cm2で60倍に発泡し
た。24時間熟成後、寸法300mm×250mm×5
0mmの金型を取付けたVS成形機で成形した。成形条
件はスチーム圧力0.7kg/cm2、10秒加熱後、
金型を3秒水冷し、次いで真空放冷し成形品を取出し
た。予備発泡時のブロッキング量と成形品の外観の結果
を表2に示す。但し、ブロッキング量は、予備発泡粒子
の総重量に対するブロック物(目開き5mmの篩上に残
るもの)の重量比率で示す。Table 1 shows the particle size distribution of the expandable polystyrene particles obtained in the above Examples and Comparative Examples. In each example and comparative example, 0.9 g of zinc stearate was mixed with 300 g of the D-cut product using a small ribbon blender. These expandable styrene particles were foamed 60 times with a small preliminary foaming machine at a steam blowing pressure of 1.0 kg / cm 2 . After aging for 24 hours, dimensions 300mm x 250mm x 5
Molding was performed with a VS molding machine equipped with a 0 mm mold. The molding conditions were as follows: steam pressure 0.7 kg / cm 2 , heating for 10 seconds,
The mold was water-cooled for 3 seconds, then allowed to cool in a vacuum, and a molded product was taken out. Table 2 shows the results of the amount of blocking during prefoaming and the appearance of the molded article. However, the blocking amount is indicated by the weight ratio of the block (the one remaining on the sieve having an opening of 5 mm) to the total weight of the pre-expanded particles.
【0022】[0022]
【表1】 [Table 1]
【0023】Aカット:5メッシュ(4.00mm)を
通過し8メッシュ(2.38mm)を通過しないもの Bカット:8メッシュを通過し12メッシュ(1.41
mm)を通過しないもの Cカット:12メッシュを通過し20メッシュ(0.8
4mm)を通過しないもの Dカット:20メッシュを通過し28メッシュ(0.5
9mm)を通過しないもの Eカット:28メッシュを通過し42メッシュ(0.3
5mm)を通過しないもの 微粒子:42メッシュを通過するもの * 比重1.01の水中に粒子10gを入れ、浮いてく
る気泡混入ビーズの重量を測定し、割合を計算した。 ** 目視判定。偏平粒子は、白色楕円状のため容易に
判別できる。A cut: one that passes 5 meshes (4.00 mm) but does not pass 8 meshes (2.38 mm) B cut: 12 meshes that pass 8 meshes (1.41 mm)
mm) that does not pass through C cut: passes through 12 meshes and 20 meshes (0.8 mm)
4 mm) D cut: 28 mesh (0.5
9 mm) E-cut: 42 mesh (0.3
5 mm) not passing Fine particles: passing 42 mesh * 10 g of particles were put in water having a specific gravity of 1.01, the weight of the floating bubble-containing beads was measured, and the ratio was calculated. ** Visual judgment. Flat particles can be easily identified because of their white elliptical shape.
【0024】[0024]
【表2】 * 目視判定。成形品表面の平滑性、融着性を判別し
た。[Table 2] * Visual judgment. The smoothness and the fusibility of the surface of the molded product were determined.
【0025】[0025]
【発明の効果】本発明によれば、偏平粒子が無くなり、
予備発泡特性や成形特性を損なうことなしに粒子径分布
の狭い発泡性ビニル系樹脂粒子を得ることができ、ビー
ズの利用率が向上し経済的に極めて有利である。According to the present invention, flat particles are eliminated,
Foamable vinyl-based resin particles having a narrow particle size distribution can be obtained without impairing the pre-foaming properties and molding properties, and the utilization rate of beads is improved, which is extremely economically advantageous.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭59−202202(JP,A) 特開 平3−258806(JP,A) (58)調査した分野(Int.Cl.7,DB名) C08F 2/18 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-202202 (JP, A) JP-A-3-258806 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) C08F 2/18
Claims (5)
の存在下に、ビニル系単量体を懸濁重合するに際し、水
溶性亜硫酸塩又はその前駆物質を、重合開始前又は重合
率30重量%以下の段階で加え、その後でかつ重合率が
20〜60重量%の間に難溶性リン酸塩を1回以上添加
し、さらに難溶性リン酸塩の添加後であって重合率50
〜70重量%の間に過酸化水素を添加して重合を行い、
重合途中又は重合後に発泡剤を含浸せしめることを特徴
とする発泡性ビニル系樹脂粒子の製造法。When a vinyl monomer is subjected to suspension polymerization in the presence of a sparingly soluble phosphate and an anionic surfactant, a water-soluble sulfite or a precursor thereof is mixed with a water-soluble sulfite before starting polymerization or at a polymerization rate of 30%. % Of the low-soluble phosphate, and after that, while adding the sparingly soluble phosphate one or more times while the degree of polymerization is 20 to 60% by weight,
The polymerization is carried out by adding hydrogen peroxide between ~ 70% by weight,
A method for producing expandable vinyl resin particles, comprising impregnating a foaming agent during or after polymerization.
が、ビニル系単量体に対して0.0001〜0.05重
量%である請求項1記載のビニル系樹脂粒子の製造法。2. The method for producing vinyl resin particles according to claim 1, wherein the amount of the water-soluble sulfite or its precursor is 0.0001 to 0.05% by weight based on the vinyl monomer.
その前駆物質に対して、当量比で0.8以上である請求
項1又は2記載のビニル系樹脂粒子の製造法。3. The process for producing vinyl resin particles according to claim 1, wherein the amount of hydrogen peroxide is 0.8 or more in equivalent ratio to the water-soluble sulfite or its precursor.
の一種又は二種以上の混合物である請求項1、2又は3
記載のビニル系樹脂粒子の製造法。4. The foaming agent according to claim 1, 2 or 3, wherein the foaming agent is one or a mixture of two or more saturated hydrocarbons having 3 to 6 carbon atoms.
The method for producing vinyl resin particles according to the above.
%以上含有するものである請求項1、2、3又は4記載
のビニル系樹脂粒子の製造法。5. The method for producing vinyl resin particles according to claim 1, wherein the vinyl monomer contains 50% by weight or more of styrene.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP6337992A JP3125418B2 (en) | 1992-03-19 | 1992-03-19 | Method for producing expandable vinyl resin particles |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP6337992A JP3125418B2 (en) | 1992-03-19 | 1992-03-19 | Method for producing expandable vinyl resin particles |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH05262828A JPH05262828A (en) | 1993-10-12 |
JP3125418B2 true JP3125418B2 (en) | 2001-01-15 |
Family
ID=13227606
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JP6337992A Expired - Fee Related JP3125418B2 (en) | 1992-03-19 | 1992-03-19 | Method for producing expandable vinyl resin particles |
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JP (1) | JP3125418B2 (en) |
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CN110713619A (en) * | 2018-07-12 | 2020-01-21 | 第一工业制药株式会社 | Method for producing expandable styrene resin particles |
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- 1992-03-19 JP JP6337992A patent/JP3125418B2/en not_active Expired - Fee Related
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