JPH03215528A - Method of irradiation-induced vulcanization of natural rubber latex - Google Patents
Method of irradiation-induced vulcanization of natural rubber latexInfo
- Publication number
- JPH03215528A JPH03215528A JP25756189A JP25756189A JPH03215528A JP H03215528 A JPH03215528 A JP H03215528A JP 25756189 A JP25756189 A JP 25756189A JP 25756189 A JP25756189 A JP 25756189A JP H03215528 A JPH03215528 A JP H03215528A
- Authority
- JP
- Japan
- Prior art keywords
- hydroperoxide
- natural rubber
- latex
- added
- rubber latex
- 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.)
- Pending
Links
- 229920006173 natural rubber latex Polymers 0.000 title claims abstract description 26
- 238000004073 vulcanization Methods 0.000 title claims abstract description 23
- 238000000034 method Methods 0.000 title claims description 31
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims abstract description 17
- 229920001971 elastomer Polymers 0.000 claims abstract description 17
- 239000007787 solid Substances 0.000 claims abstract description 10
- 230000005865 ionizing radiation Effects 0.000 claims abstract description 9
- CIHOLLKRGTVIJN-UHFFFAOYSA-N tert‐butyl hydroperoxide Chemical compound CC(C)(C)OO CIHOLLKRGTVIJN-UHFFFAOYSA-N 0.000 claims abstract description 6
- 239000000203 mixture Substances 0.000 claims abstract description 5
- 230000001678 irradiating effect Effects 0.000 claims abstract 2
- 230000005855 radiation Effects 0.000 claims description 18
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 claims description 10
- 238000010894 electron beam technology Methods 0.000 claims description 4
- XSZYESUNPWGWFQ-UHFFFAOYSA-N 1-(2-hydroperoxypropan-2-yl)-4-methylcyclohexane Chemical compound CC1CCC(C(C)(C)OO)CC1 XSZYESUNPWGWFQ-UHFFFAOYSA-N 0.000 claims description 2
- YQHLDYVWEZKEOX-UHFFFAOYSA-N cumene hydroperoxide Chemical compound OOC(C)(C)C1=CC=CC=C1 YQHLDYVWEZKEOX-UHFFFAOYSA-N 0.000 claims description 2
- CQEYYJKEWSMYFG-UHFFFAOYSA-N butyl acrylate Chemical compound CCCCOC(=O)C=C CQEYYJKEWSMYFG-UHFFFAOYSA-N 0.000 claims 4
- SPTHWAJJMLCAQF-UHFFFAOYSA-N 1,2-di(propan-2-yl)benzene;hydrogen peroxide Chemical compound OO.CC(C)C1=CC=CC=C1C(C)C SPTHWAJJMLCAQF-UHFFFAOYSA-N 0.000 claims 1
- MIRQGKQPLPBZQM-UHFFFAOYSA-N 2-hydroperoxy-2,4,4-trimethylpentane Chemical compound CC(C)(C)CC(C)(C)OO MIRQGKQPLPBZQM-UHFFFAOYSA-N 0.000 claims 1
- 229920000126 latex Polymers 0.000 abstract description 21
- 239000004816 latex Substances 0.000 abstract description 21
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 abstract description 3
- 238000002156 mixing Methods 0.000 abstract description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 8
- 238000003756 stirring Methods 0.000 description 8
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 5
- 235000011114 ammonium hydroxide Nutrition 0.000 description 5
- 239000011521 glass Substances 0.000 description 5
- 229910021529 ammonia Inorganic materials 0.000 description 4
- 239000007864 aqueous solution Substances 0.000 description 4
- 239000005018 casein Substances 0.000 description 3
- BECPQYXYKAMYBN-UHFFFAOYSA-N casein, tech. Chemical compound NCCCCC(C(O)=O)N=C(O)C(CC(O)=O)N=C(O)C(CCC(O)=N)N=C(O)C(CC(C)C)N=C(O)C(CCC(O)=O)N=C(O)C(CC(O)=O)N=C(O)C(CCC(O)=O)N=C(O)C(C(C)O)N=C(O)C(CCC(O)=N)N=C(O)C(CCC(O)=N)N=C(O)C(CCC(O)=N)N=C(O)C(CCC(O)=O)N=C(O)C(CCC(O)=O)N=C(O)C(COP(O)(O)=O)N=C(O)C(CCC(O)=N)N=C(O)C(N)CC1=CC=CC=C1 BECPQYXYKAMYBN-UHFFFAOYSA-N 0.000 description 3
- 235000021240 caseins Nutrition 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 239000002516 radical scavenger Substances 0.000 description 2
- VZGDMQKNWNREIO-UHFFFAOYSA-N tetrachloromethane Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- GOXQRTZXKQZDDN-UHFFFAOYSA-N 2-Ethylhexyl acrylate Chemical compound CCCCC(CC)COC(=O)C=C GOXQRTZXKQZDDN-UHFFFAOYSA-N 0.000 description 1
- GUTLYIVDDKVIGB-OUBTZVSYSA-N Cobalt-60 Chemical compound [60Co] GUTLYIVDDKVIGB-OUBTZVSYSA-N 0.000 description 1
- 206010040880 Skin irritation Diseases 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- -1 acrylic ester Chemical class 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 230000015271 coagulation Effects 0.000 description 1
- 238000005345 coagulation Methods 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000007429 general method Methods 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 239000003112 inhibitor Substances 0.000 description 1
- 235000013336 milk Nutrition 0.000 description 1
- 239000008267 milk Substances 0.000 description 1
- 210000004080 milk Anatomy 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 229930014626 natural product Natural products 0.000 description 1
- XKLJHFLUAHKGGU-UHFFFAOYSA-N nitrous amide Chemical compound ON=N XKLJHFLUAHKGGU-UHFFFAOYSA-N 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000007781 pre-processing Methods 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000002285 radioactive effect Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000036556 skin irritation Effects 0.000 description 1
- 231100000475 skin irritation Toxicity 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
Landscapes
- Heating, Cooling, Or Curing Plastics Or The Like In General (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
- Processes Of Treating Macromolecular Substances (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は天然ゴムラテックス（以下ＮＲＬと略記する場
合がある）の放射線加硫方法に関する．更に詳しくは、
アクリル酸ｒｌ−ブチル（以下ＢＡと略記する場合があ
る）を加え、ｔＭ性放射線を照射する天然ゴムラテック
スの放射線加硫において、あらかじめヒドロパーオギサ
イドを添加することを特徴とする天然ゴムラテックスの
前処理方法に関する．
（従来の技術）
ＮＲＬの放射線加硫は、ニトロソアミンの副生かない加
硫法であり、得られるゴムが高い透明性と柔軟性を有す
るため、手術用手袋、放射性汚染防護用ゴム手袋、カテ
ーテル等種々のゴム製品の製造原料として幅広い用途が
ある．しかし、放射線加硫では、照射のコストが安価で
はないため、少ない照射線量で放射線加硫する技術の開
発が望まれている．本発明者らはすでにアクリル酸２エ
チルヘキシル（以下２ＥＨＡと略記する場合がある）と
四塩化炭素を加え、電離性放射線を照射するに先立ち親
水性で液状のヒドロパーオキサイドを添加することを特
徴とする天然ゴムラテックスの前処理方法を提案した（
特願昭６３−５４５１４），これは、前述の照射コスト
低減を目的としたしのであり、１０〜２０ｋｌｌｌ’／
程度の少ない線量で加硫できる方法を提供した．しかし
ながら、この方法で製造したゴム製品は特異な臭気を有
し、使用者に不快感を与えたり皮膚を刺激することであ
った．（発明が解決しようとする課題》
本発明者らはこの臭気の原因について研究したところ、
この臭気が残存した２ＥＨＡによることがわかった，２
ＥＨＡは重合性の高いモノマーであるが、放射線加硫の
過程で完全に１００％重合することが困難で、微量の２
ＥＨＡがラテックス中に残存し、この２ＥＨＡの蒸気圧
が低いため、ラテックスから手段などを製造する過程で
１００％完全に除去することが困龍で、Ｗ！１ｊＬの２
ＥＨＡが手袋などに残存するのであった．ＦＲ量とはい
え２ＥＨＡが手袋などに残存することは、単に臭気の点
からだけではなく、皮膚刺激などの点からも好ましくな
いことは明らかであり、より安全な放射線加硫法の確立
が望まれていた．このため、本発明者らは、さらに研究
を続け、今回の発明を完成するに至った．
（課趙を解決するための手段）
本発明の目的は、経済的かつ安全な放射線加硫方法を提
供することにある．更に詳しくは、少ない照射線量で天
然ゴムラテックスを放射線加硫し、しかも使用した促進
剤が手袋等に残存しない放射線加硫方法を提供すること
にある．課題を解決するための手段として本発明者らが
とった手段は、蒸気圧の高いアクリル酸エステルの泗択
であった．すでに本発明者らは、各種アクリル酸エステ
ルの放射線加硫効率について研究し、２ＥＨＡの他にア
クリル酸ローブチル（ＢＡ）がすぐれた放射線加硫促進
剤となることを見い出していた（特願昭６０−１８１１
３２） Ｌ．かじ、ＢＡを添加すると天然ゴムラテッ
クスの粘度が上昇し、時には凝固する傾向があり、使用
しにくいという問題があった．そこで本発明者は、この
粘度上昇の原因と防止法について検討し、天然ゴムラテ
ックスに水酸化カリウム水溶液あるいはカゼイン水溶液
を添加するという天然ゴムラテックスの一般的な安定化
の方法が有効であることを見い出した．これによって、
ＢＡを添加しても凝固しない天然ゴムラテックスが得ら
れ、本発明を完成するに至った．以下に本発明の詳細を
述べる．本発明にしたがってラテックスへ配合されるし
ドロパーオキサイドは、ｔ−ブチルヒドロパーオキサイ
ド、クミルハイドロパーオキサイド、ジーイソグロピル
ベンゼンヒドロパーオキサイド、ｐ−メンタンヒドロパ
ーオキサイド、１，１，３．３−テトラメチルブチルヒ
ドロパーオキサイド及びそれらの混合物から成る群から
選択される．配合される割合は、ゴム固形分１００重量
部当り０．０５〜２重量部（以下０．０５〜２ ｐｈｒ
と略記する場合がある）であり、好ましくは０．１〜１
ｐｈｒである、ヒドロパーオキサイドが０．０５ ｐ
ｈｒ以下の場合は加硫促進効果が少なく、２ｐｈｒ以上
では経済性を低くするため好ましくない．これらしドロ
バーオキサイドは液状であるため、天然ゴムラテックス
への添加法は、特殊な添加法を必要とせず、天然ゴムラ
テックスをゆるやかにかき混ぜながら直接添加すればよ
い、ヒドロパーオキサイドをアンモニア水と混合してか
ら添加してもよい、ヒドロパーオキサイドによる天然ゴ
ムラテックスの前処理効果を高めるため、添加後少なく
とも３０分間天然ゴムラテックスをかき混ぜ、２時間以
上放置することが望ましい．この放置の過程でヒドロパ
ーオキサイドがラテックス中でなんらかの反応を引起こ
し、加硫線量の低減をもたらす、ヒドロパーオキサイド
の前処理中の反応の詳細については不明であるが、加硫
線量の低減に極めて効果的である事実と前処理だけでは
前加硫に至らない事実から推定すると、ラテックスの水
中には天然のラジカル捕捉剤が存在し、これが放射線加
硫を抑制しているが、親水性で液状のヒドロパーオキサ
イドがこの天然のラジカル捕捉剤を分解し、放射線加硫
の抑制因子を除去すると考えられる．
本発明にしたがってラテックスへ配合されるＢＡの割合
は、０．５〜１０ ｐｈｒであり、好ましくは１ 〜２
０ ｐｈｒである．ＢＡが０．５ ｐｈｒ以下の場合は
加硫促進効果が少な（ 、３０ ｐｈｒ以上では経済性
を低くするばかりかゴムの引張強さが低下し好ましくな
い，ＢＡのラテックスの添加法は、特殊な添加法を必要
としない．ただし、ラテックスへの急激なＢＡの添加は
ゴムの凝固をまねく恐れがあるので避けなければならず
、ラテックスをゆるやかにかき混ぜながら徐々に添加す
ることが好ましい．添加にあたってあらかじめ界面活性
剤を用いてＢＡを乳化して添加してもよい．ゴム粒子は
ＢＡを吸収して膨潤するため、固形分体積が増加し、ラ
テックスの粘度が上昇するが、これはあらかじめラテッ
クスをアンモニア水などにより希釈して固形分濃度を下
げておくことにより防止できる，ＢＡを均一にゴム粒子
中に溶解させるため、添加後少なくとも３０分間ラテッ
クスをかき混ぜ、少なくとも１０時間〜２４時間程度放
置することが望ましい．放置時間が２４時間以上になる
とＢＡの加水分解などが起るので好ましくない。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a radiation vulcanization method for natural rubber latex (hereinafter sometimes abbreviated as NRL). For more details,
Natural rubber latex is characterized in that hydroperoxide is added in advance during radiation vulcanization of natural rubber latex in which RL-butyl acrylate (hereinafter sometimes abbreviated as BA) is added and tM radiation is irradiated. Concerning pre-processing methods. (Prior art) NRL's radiation vulcanization is a vulcanization method that does not produce nitrosamine by-products, and the resulting rubber has high transparency and flexibility, making it suitable for use in surgical gloves, rubber gloves for protecting against radioactive contamination, catheters, etc. It has a wide range of uses as a raw material for manufacturing various rubber products. However, in radiation vulcanization, the cost of irradiation is not cheap, so there is a desire to develop a technology for radiation vulcanization with a small irradiation dose. The present inventors have already added 2-ethylhexyl acrylate (hereinafter sometimes abbreviated as 2EHA) and carbon tetrachloride, and added a hydrophilic liquid hydroperoxide prior to irradiation with ionizing radiation. We proposed a pretreatment method for natural rubber latex (
(Japanese Patent Application No. 63-54514), this was aimed at reducing the irradiation cost mentioned above, and the
We have provided a method that allows vulcanization with a small amount of radiation. However, the rubber products manufactured by this method have a peculiar odor that causes discomfort to the user and irritates the skin. (Problem to be solved by the invention) The present inventors researched the cause of this odor and found that
It turned out that this odor was due to residual 2EHA, 2
EHA is a highly polymerizable monomer, but it is difficult to completely polymerize 100% during the radiation vulcanization process, and a trace amount of 2
Because EHA remains in latex and the vapor pressure of this 2EHA is low, it is difficult to completely remove it 100% in the process of manufacturing means from latex, so W! 1jL 2
EHA remained on gloves, etc. It is clear that 2EHA remaining in gloves, etc., despite the FR amount, is undesirable not only from the point of view of odor but also from the point of view of skin irritation, and it is desirable to establish a safer radiation vulcanization method. It was being held. For this reason, the inventors continued their research and completed the present invention. (Means for solving the problem) An object of the present invention is to provide an economical and safe radiation vulcanization method. More specifically, it is an object of the present invention to provide a radiation vulcanization method for radiation vulcanization of natural rubber latex with a small radiation dose and in which the accelerator used does not remain on gloves or the like. The method taken by the present inventors to solve the problem was to select an acrylic ester with a high vapor pressure. The present inventors had already studied the radiation vulcanization efficiency of various acrylic esters, and found that in addition to 2EHA, loobyl acrylate (BA) was an excellent radiation vulcanization accelerator (Japanese Patent Application No. 1983). -1811
32) L. When BA is added, the viscosity of natural rubber latex increases and sometimes it tends to coagulate, making it difficult to use. Therefore, the present inventor investigated the causes of this viscosity increase and methods for preventing it, and found that a general method for stabilizing natural rubber latex, which involves adding an aqueous potassium hydroxide solution or an aqueous casein solution to natural rubber latex, is effective. I found it. by this,
Natural rubber latex that does not coagulate even when BA is added has been obtained, and the present invention has been completed. The details of the present invention are described below. The dropperoxides incorporated into the latex according to the present invention include t-butyl hydroperoxide, cumyl hydroperoxide, diisoglopylbenzene hydroperoxide, p-menthane hydroperoxide, 1,1,3. selected from the group consisting of 3-tetramethylbutyl hydroperoxide and mixtures thereof. The blending ratio is 0.05 to 2 parts by weight (hereinafter 0.05 to 2 phr) per 100 parts by weight of rubber solid content.
), preferably 0.1 to 1
phr, hydroperoxide is 0.05 p
If it is less than hr, the effect of accelerating vulcanization will be small, and if it is more than 2 phr, the economical efficiency will be low, which is not preferable. Since these drover oxides are in liquid form, the addition method to natural rubber latex does not require any special addition method, and can be added directly to natural rubber latex while gently stirring. Hydroperoxide is mixed with ammonia water and In order to enhance the effect of pretreatment of natural rubber latex with hydroperoxide, which may be added after mixing, it is desirable to stir the natural rubber latex for at least 30 minutes after addition and leave it for at least 2 hours. During this standing process, the hydroperoxide causes some kind of reaction in the latex, resulting in a reduction in the vulcanization dose.The details of the reaction during the pretreatment of the hydroperoxide are unknown, but the vulcanization dose can be reduced. Judging from the fact that it is extremely effective and the fact that pretreatment alone does not lead to prevulcanization, it is assumed that there are natural radical scavengers in latex water that suppress radiation vulcanization. It is thought that liquid hydroperoxide decomposes this natural radical scavenger and removes the inhibitor of radiation vulcanization. The proportion of BA incorporated into the latex according to the invention is between 0.5 and 10 phr, preferably between 1 and 2 phr.
0 phr. If BA is less than 0.5 phr, the effect of promoting vulcanization is small (and if it is more than 30 phr, it not only becomes less economical but also reduces the tensile strength of the rubber, which is undesirable. No addition method is required.However, sudden addition of BA to latex may cause coagulation of the rubber, so it must be avoided, and it is preferable to add BA gradually while stirring the latex gently.Before adding BA, BA may be emulsified and added using a surfactant.The rubber particles absorb BA and swell, increasing the solid volume and increasing the viscosity of the latex. This can be prevented by lowering the solid content concentration by diluting with water etc. In order to uniformly dissolve BA into the rubber particles, it is necessary to stir the latex for at least 30 minutes after addition and leave it for at least 10 to 24 hours. Desirable.If left for more than 24 hours, hydrolysis of BA will occur, which is not preferable.
ヒドロパーオキサイドとＢＡを添加したラテツクスに照
射する電離性放射線としては、種類を限定する必要はな
いが、γ線、電子線、電子線などが工業的意義を有して
いる．
しドロパーオキサイドとＢＡを添加したラテックスを加
硫するに必要な線量は、ＢＡとしドロパオキサイドの添
加量に依存して決定されるが、通常１〜３０κＧｌ／で
あり、好ましくは５〜２０ ＫＧｙである．線量率は特
に限定する必要がない．照射にあたってはラテックスが
安定に存在しうる温度であれば特に限定する必要はない
が、温度が高いほど必要線量は少なくなる．照射中の雰
囲気についても特に限定する必要はない．本発明によっ
て得られる放射線加硫ラテックスのコロイド的性質は、
照射前と変りがなく、当該技術分野で通常行われている
各種配合技術を適用でき、さらに浸漬その他の方法によ
って各種ゴム製品を製造することができる．
以下に本発明の実施例及び比較例にしたがって説明する
．なお、天然物であるラテックスは、産地によって、ま
た産地の天候、季節によって性質が異なることがあるた
め本実施例及び比較例と異なる物性値となることもある
が、それは本発明の本質的意義をそこなうものではない
．
（実施例》
Ｋ胤旦ユ
かき混ぜ棒をとりつけたガラスフラスコに高アンモニア
天然ゴムラテックス（マレイシア産、ゴム固形分６０．
１％》を７５０ｇ取り、毎分４０回転の速度でかき混ぜ
ながら１％のアンモニア水を２３０ｍｌと１０％の水酸
化カリウム水溶液を９ｍｌ加えた．このラテックスに０
．１５ ｐｈｒのｔ−ブチルヒドロパーオキサイド（日
本油脂株式会社製、バーブチルＨ、純度６９％）を添加
し、３０分間かき混ぜた．一昼夜放置した後、５ ｐｈ
ｒのＢＡを添加し、３０分間かき混ぜた．一昼夜放置し
た．これを１００ ｍｌのガラス製容器に移し、室温で
コバルト６０からのγ線を線量率１０ ＫＧＶ／時で所
定の時間照射した．照射後ラテックスを水平なガラス板
の上に流延し、室温で透明になるまで乾燥した後ガラス
板から剥離し、８０′″で１時間乾燥し、厚さ０． ４
５ｍのフィルムを得た．これをＪＩＳ ２−６３０１の
方法にしたがって引張強さを測定した．結果を表−１に
示した．Ｌ帆勇ユ
かき混ぜ棒をとりつけたガラスフラスコに高アンモニア
天然ゴムラテックス（マレイシア産、ゴム固形分６０．
１％）を７５０ｇ取り、毎分４０回転の速度でかき混ぜ
ながら１％のアンモニア水を２３０ｍｌと１０％の水酸
化カリウム水溶液を９ ｍｌ加えた．これに５ ｐｈｒ
のＢＡを添加し実施例１と同様にして照射し、乾燥して
引張強さを測定した．結果を表−１に示した．
Ｋ止■ユ
かき混ぜ棒をとりつけたカラスフラスコに高アンモニア
天然ゴムラテックス（マレイシア産、ゴム固形分６０．
３％）を７５０ｇ取り、毎分４０回転の速度でかき混ぜ
ながら１％のアンモニア水を２３０ｍｌと１０％のミル
クカゼイン水溶液を９０］１加えた．このラテックスに
Ｏ． Ｉｐｈｒのｔ−ブチルヒドロパーオキサイド（日
本油脂株式会社製、パーブチルＨ、純度６９％）を添加
し、３０分間かき混ぜた．一昼夜放置した後１００ｍｌ
のガラス製容器に移し、室温で加速電圧が３ ｍｙ，電
流が２５ｍＡの電子加速器からの電子線を線量率２．３
３κＧｙ／秒で所定の時間照射した．照射後ラテックス
を水平なガラス板の上に流延し、室温で透明になるまで
乾燥した後ガラス板から剥離し、８０゜で１時間乾燥し
、厚さ０．４５ｍのフィルムを得た．これを ＪＩＳ
７− ６３０１の方法にしたがって引張強さを測定した
．結果を表−２に示した．
匿敷！ユ
かき混ぜ棒とりつけたガラスフラスコに高アンモニア天
然ゴムラテックス（マレイシア産、ゴム固形分６０．３
％）を７５０ｇ取り、毎分４０回転の速度でかき混ぜな
がら１％のアンモニア水を２３０ｍｌと１０％のカゼイ
ン水溶液を９ｍｌ加えた．これに５ｐｈｒのＢＡを添加
し実施例２と同様にして照射し、乾燥して引張強さを測
定した．結果を表−２に示した。Although there is no need to limit the type of ionizing radiation irradiated to latex containing hydroperoxide and BA, gamma rays, electron beams, electron beams, etc. have industrial significance. The dose required to vulcanize latex containing dropperoxide and BA is determined depending on the amounts of BA and dropperoxide added, but is usually 1 to 30 kGl/, preferably 5 to 20 kGl/. It is KGy. There is no need to specifically limit the dose rate. There is no need to limit the irradiation temperature as long as the temperature allows the latex to exist stably, but the higher the temperature, the lower the required dose. There is no need to particularly limit the atmosphere during irradiation. The colloidal properties of the radiation-cured latex obtained by the present invention are as follows:
There is no difference from before irradiation, and various compounding techniques commonly used in the technical field can be applied, and various rubber products can be manufactured by dipping and other methods. The following describes examples of the present invention and comparative examples. Note that latex, which is a natural product, may have different properties depending on the region of production, weather, and season of the region, so the physical property values may differ from those of this example and comparative example. However, this is not the essential meaning of the present invention. It does not harm the (Example) High ammonia natural rubber latex (produced in Malaysia, rubber solid content 60.
1%'' was taken, and while stirring at a speed of 40 revolutions per minute, 230 ml of 1% ammonia water and 9 ml of 10% potassium hydroxide aqueous solution were added. 0 for this latex
．． 15 phr of t-butyl hydroperoxide (Verbutyl H, manufactured by NOF Corporation, purity 69%) was added and stirred for 30 minutes. After leaving it for a day and night, 5 ph
of BA was added and stirred for 30 minutes. I left it overnight. This was transferred to a 100 ml glass container and irradiated with gamma rays from cobalt-60 at a dose rate of 10 KGV/hour at room temperature for a predetermined period of time. After irradiation, the latex was cast onto a horizontal glass plate, dried at room temperature until transparent, peeled off from the glass plate, and dried at 80'' for 1 hour to a thickness of 0.4.
A 5m film was obtained. The tensile strength of this was measured according to the method of JIS 2-6301. The results are shown in Table 1. High ammonia natural rubber latex (produced in Malaysia, rubber solids content 60.
1%) was taken, and while stirring at a speed of 40 revolutions per minute, 230 ml of 1% ammonia water and 9 ml of 10% potassium hydroxide aqueous solution were added. 5 phr for this
BA was added and irradiated in the same manner as in Example 1, dried, and the tensile strength was measured. The results are shown in Table 1. High ammonia natural rubber latex (produced in Malaysia, rubber solids content 60.
3%) was taken, and while stirring at a speed of 40 revolutions per minute, 230ml of 1% ammonia water and 90ml of 10% milk casein aqueous solution were added. This latex has O. Iphr t-butyl hydroperoxide (Perbutyl H, manufactured by NOF Corporation, purity 69%) was added and stirred for 30 minutes. 100ml after leaving it for a day and night
The electron beam from an electron accelerator with an accelerating voltage of 3 my and a current of 25 mA was applied at room temperature to a dose rate of 2.3.
Irradiation was performed at 3κGy/sec for a predetermined period of time. After irradiation, the latex was cast onto a horizontal glass plate, dried at room temperature until it became transparent, peeled off from the glass plate, and dried at 80° for 1 hour to obtain a film with a thickness of 0.45 m. This is JIS
The tensile strength was measured according to the method of 7-6301. The results are shown in Table 2. Hidden! High ammonia natural rubber latex (produced in Malaysia, rubber solids content 60.3
%) was taken, and while stirring at a speed of 40 revolutions per minute, 230 ml of 1% ammonia water and 9 ml of 10% casein aqueous solution were added. 5 phr of BA was added to this, irradiated in the same manner as in Example 2, dried, and the tensile strength was measured. The results are shown in Table-2.
実施例と比較例を対比させると、本発明の有為なことが
明白である．Comparing Examples and Comparative Examples, it is clear that the present invention is advantageous.
Claims (1)
し、しかる後にアクリル酸ｎ−ブチルを添加し、電離性
放射線を照射することを特徴とする天然ゴムラテックス
の放射線加硫方法。 ２、アクリル酸ｎ−ブチルを添加しても、粘度が著しく
上昇しないよう水酸化カリウム等で安定化された天然ゴ
ムラテックスを用いることを特徴とする特許請求の範囲
第１項記載の方法。 ３、ヒドロパーオキサイドの添加量がゴム固形分１００
重量部当り０．０５〜２．０重量部であることを特徴と
する特許請求の範囲第１項記載の方法。 ４、ヒドロパーオキサイドを添加した天然ゴムラテック
スを２時間以上放置した後、アクリル酸ｎ−ブチルを添
加することを特徴とする特許請求の範囲第１項記載の方
法。 ５、アクリル酸ｎ−ブチルをゴム固形分１００重量部当
り０．５〜２０重量部添加する特許請求の範囲第１項記
載の方法。 ６、ヒドロパーオキサイドがｔ−ブチルヒドロパーオキ
サイド、クミルハイドロパーオキサイド、ジ−イソプロ
ピルベンゼンヒドロパーオキサイド、ｐ−メンタンヒド
ロパーオキサイド、１，１，３，３−テトラメチルブチ
ルヒドロパーオキサイド及びそれらの混合物から成る群
から選択されることを特徴とする特許請求の範囲第１項
記載の方法。 ７、電離性放射線５〜３０ＫＧＹ照射することを特徴と
する特許請求の範囲第１項記載の方法。 ８、電離性放射線がγ線である特許請求の範囲第１項記
載の方法。 ９、電離性放射線が電子線である特許請求の範囲第１項
記載の方法。 １０、電離性放射線がＸ線である特許請求の範囲第１項
記載の方法。[Claims] 1. A radiation vulcanization method for natural rubber latex, which comprises adding hydroperoxide to natural rubber latex, then adding n-butyl acrylate, and irradiating the mixture with ionizing radiation. 2. The method according to claim 1, characterized in that natural rubber latex stabilized with potassium hydroxide or the like is used so that the viscosity does not increase significantly even when n-butyl acrylate is added. 3. The amount of hydroperoxide added is 100% rubber solids.
The method according to claim 1, characterized in that the amount is 0.05 to 2.0 parts by weight per part by weight. 4. The method according to claim 1, wherein n-butyl acrylate is added after the natural rubber latex to which hydroperoxide has been added is left to stand for 2 hours or more. 5. The method according to claim 1, wherein n-butyl acrylate is added in an amount of 0.5 to 20 parts by weight per 100 parts by weight of rubber solids. 6. The hydroperoxide is t-butyl hydroperoxide, cumyl hydroperoxide, di-isopropylbenzene hydroperoxide, p-menthane hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, and the like. A method according to claim 1, characterized in that the method is selected from the group consisting of mixtures of. 7. The method according to claim 1, characterized in that 5 to 30 KGY of ionizing radiation is irradiated. 8. The method according to claim 1, wherein the ionizing radiation is gamma rays. 9. The method according to claim 1, wherein the ionizing radiation is an electron beam. 10. The method according to claim 1, wherein the ionizing radiation is X-rays.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25756189A JPH03215528A (en) | 1989-10-02 | 1989-10-02 | Method of irradiation-induced vulcanization of natural rubber latex |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25756189A JPH03215528A (en) | 1989-10-02 | 1989-10-02 | Method of irradiation-induced vulcanization of natural rubber latex |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03215528A true JPH03215528A (en) | 1991-09-20 |
Family
ID=17307987
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25756189A Pending JPH03215528A (en) | 1989-10-02 | 1989-10-02 | Method of irradiation-induced vulcanization of natural rubber latex |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03215528A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008535998A (en) * | 2005-04-13 | 2008-09-04 | アール．ティー． ヴァンダービルト カンパニー インコーポレーティッド | Compositions and methods for curing latex compounds |
-
1989
- 1989-10-02 JP JP25756189A patent/JPH03215528A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008535998A (en) * | 2005-04-13 | 2008-09-04 | アール．ティー． ヴァンダービルト カンパニー インコーポレーティッド | Compositions and methods for curing latex compounds |
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