JPH04185651A - Production of crosslinked polyolefin molding - Google Patents
Production of crosslinked polyolefin moldingInfo
- Publication number
- JPH04185651A JPH04185651A JP2317459A JP31745990A JPH04185651A JP H04185651 A JPH04185651 A JP H04185651A JP 2317459 A JP2317459 A JP 2317459A JP 31745990 A JP31745990 A JP 31745990A JP H04185651 A JPH04185651 A JP H04185651A
- Authority
- JP
- Japan
- Prior art keywords
- molded product
- crystalline
- polyolefin
- crosslinking
- ultraviolet rays
- 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)
- Treatments Of Macromolecular Shaped Articles (AREA)
Abstract
Description
この発明は、紫外線照射架橋法によって架橋ポリオレフ
ィン成形物を製造する方法に関する。The present invention relates to a method for producing a crosslinked polyolefin molded article by an ultraviolet irradiation crosslinking method.
ポリエチレンなどに代表されるポリオレフィンの架橋方
法としては、電子線などによる放射線架橋や有機過酸化
物による化学架橋なとか知られているユ
放射線架橋は、架橋効率が良いが、放射線の透過能率の
関係で、厚さがＩ＋＋ｖ程度以下の薄肉の成形品に限ら
れ、まに設備費用が嵩み、操作も危険を伴う欠点がある
。
化学架橋は、厚肉の成形品にも適用可能であるか、架橋
に時間を要し、まｆ二加熱加圧の１こめの架橋設備が必
要となる。また、有機過酸化物を添加しｆコポリオレフ
ィン組成物を押出成形、射出成形する際、有機過酸化物
の一部か分解し、Ｉ）わゆるスコーチなとが生成して成
形装置の長時間運転に支障を来すことがある。
また、絶縁電線の分野では、シラン架橋法が知られてい
る。この〇のでは、水との反応によって架橋反応を行わ
せるため、絶線層などのｍｉの厚さが３〜４ｍｍ以上と
なると水の浸透か遅く、架橋に長時間を要する。また、
微量の水分が残留し、電気的特性が十分でないなどの不
都合がある。
一方、紫外線照射による架橋については、紫外線硬化型
塗料やフォトレジストなどの分野で実用化されでいる。
しかしなから、ポリエチレンなどの結晶性ポリオレフィ
ンに対する紫外線照射による架橋７こついてはいまた実
用化されていない。
一方、本発明者等（Ｊ、先に結晶性ポリオレフィンに、
その結晶融点以上の温度条件で紫外線を照射することて
、結晶性ポリオレフィンを効率よく紫外線架橋できるこ
とを知見し、その実用化を進めている。As a crosslinking method for polyolefins such as polyethylene, radiation crosslinking using electron beams and chemical crosslinking using organic peroxides are known. Radiation crosslinking has good crosslinking efficiency, but there are problems with radiation transmission efficiency. However, it is limited to thin molded products with a thickness of about I++v or less, and has the drawbacks of high equipment costs and dangerous operation. Chemical crosslinking is not only applicable to thick-walled molded products, but also takes time for crosslinking, and requires crosslinking equipment that requires heating and pressurization. In addition, when an f-copolyolefin composition is extrusion molded or injection molded after adding an organic peroxide, a part of the organic peroxide decomposes, and a so-called scorch is generated, which causes the molding equipment to run for a long time. It may interfere with driving. Furthermore, in the field of insulated wires, a silane crosslinking method is known. In this case, the crosslinking reaction is carried out by reaction with water, so if the thickness of mi such as a disconnected wire layer is 3 to 4 mm or more, water permeation is slow and crosslinking takes a long time. Also,
There are disadvantages such as a trace amount of moisture remaining and insufficient electrical characteristics. On the other hand, crosslinking by ultraviolet irradiation has been put to practical use in fields such as ultraviolet curing paints and photoresists. However, due to difficulties in crosslinking crystalline polyolefins such as polyethylene by ultraviolet irradiation, it has not been put into practical use. On the other hand, the present inventors (J) first applied crystalline polyolefin to
We have discovered that crystalline polyolefins can be efficiently crosslinked with ultraviolet rays by irradiating them with ultraviolet rays at a temperature above their crystal melting point, and we are working to put this into practical use.
本発明は前記課題を解決するＴ二めになされｋもので、
結晶性ポリオレフィンからなる成形物に、その結晶性ポ
リオレフイノの結晶融点以上の温度条件で、波長の異な
る多種類の紫外線を照射した６のである。The present invention is the second invention to solve the above problems,
A molded article made of crystalline polyolefin was irradiated with various types of ultraviolet rays of different wavelengths at a temperature higher than the crystalline melting point of the crystalline polyolefin.
結晶融点以上の温度においては、結晶性ポリオレフイノ
はその結晶部分が全て融解状態にあり、透明性が良好に
なる。このため、紫外線の透過効率か大幅に向上し、架
橋効率か増加する。
ここで、紫外線照射による架橋効率は、まず被照射体の
光の吸収程度により決定される。
一般に光の吸収は次式で表される。
Ａ−ε・ｄ−Ｃ
Ａ 吸収量（無次元）
ε。光増感剤の分子吸光係数（１／ｍｏｌ・ａｍ）ｄ試
料厚（ｃａ）
Ｃ開始剤濃度（ｍｏｌ／Ｉ）
上式かろ明らかな通り、試料厚と開始剤濃度を一定とす
ると、分子吸光係数（ε）が大きい程、吸収量は大きく
なる。
この分子吸光係数は物質に固有の値であり、例えば、ベ
ンゾフェノンでは、ε＝１８９０Ｑ（λ＝ ２５２ ｎ
ｍ）、ε＝Ｉ５６（λ−３３１ｎｍ）である。
尚、λは、吸収ピークの紫外線波長である。
ところで、紫外線等の光において、波長が長い程、透過
性が大きいことはよく知られている。従って、肉厚なも
のを架橋（重合）させる場合には、長波長側の紫外線を
吸収させることか不可欠である。
まｆ二、紫外線照射架橋（重合）の場合は、空気中の酸
素禁止作用が存在し、架橋阻害がある為に、表面付近で
の架橋（重合）効率を高める必要がある。
本発明では、長波長の紫外線スペクトルを多くもつ光源
と短波長の紫外線スペクトルを多くもつ光源を併用する
ことで、前記課題を解決しｆコものである。
以下、この発明の詳細な説明する。
この発明で用いられる結晶性ポリオレフイノとしては、
ポリエチレン、ポリプロピレン、ポリブテノ−１、ポリ
−４−メチルペンテン−１、エチレン・ブクピレン共重
合体なとのエチレン共重合体などかあるか、なかでも低
密度ポリエチレン、高密度ポリエチレン、直鎖状ポリエ
チレン、超低密度ポリエチレン、超高分子量ポリエチレ
ンなどのポリエチレンか、架橋効率が高いものとなって
好ましい。勿論、これらの混合物であってもよい。
この結晶性ポリオレフィンは、光増感剤との混合物とし
て、種々の成形手段によって成形物とされる。この混合
物には、さらに架橋助剤あるいはこの架橋助剤と紫外線
吸収剤を混合して、成形物とすることもできる。
ここで用いられる光増感剤としては、ベンゾフェノン、
４−クロロベンゾフェノン、２−クロロベンゾフェノン
、４，４“−ジクロロヘンシフエノン、ヘキサクロロベ
ンゾフェノンなどのベンゾフェノン類や２−ベンジル−
２−ツメチルアミノ−Ｉ−（４−モルフォリンフェノー
ル）−ブタノンやクロレンディックアンハイドライト、
「サンドリー１０００Ｊ（商品名・モンサンド社製）な
どが用いられる。
この光増感剤の配合量は、結晶性ポリオレフィン１００
重量部に対して０２〜３重量重量部加好ましく、０．２
重量部未満では架橋率向上効果が得られず、また３重量
部を越えると過剰となって、架橋後の成形物−０電気的
特性、機緘的特性等が低下して好ましくない。光増感剤
の配合により、架橋効率が格段に向上し、短時間で架橋
を高いレベルまで持っていくことか可能となる。
まに、紫外線吸収剤としては、フェニルサリチレートな
どのサリチル酸誘導体、ｌ（２’−ヒドロキノ−５−メ
チルフェニル）ベンゾトリアゾールなとのベンゾトリア
ゾール類、２−ヒドロキシベンゾフェノン、２−ヒドロ
キン−４−メトキンベンゾフェノン、２−ヒドロキン−
４−オクトキノヘンゾフェノン、２．２°−ジヒドロキ
ノー４−メトキノフェノンなと゛のヒドロキシベンゾフ
ェノン類などが好適に用いられる。例えば、フェニルサ
リチレー）・は３２０ｎ１１以下の紫外線を吸収するも
ので最適である。この紫外線吸収剤の配合量は、結晶性
ポリオレフィン１００重量部に対して００５〜１重量部
の範囲で決められる。配合量が００５重量部未満ては紫
外線照射時の結晶性ポリオレフィンの劣化を防止する能
力が低く、一方１重量部を越えると紫外線劣化を制御す
ること（Ｊてきるものの照射された紫外線が紫外線吸収
剤に吸収される度合が大きくなり、架橋効果が低下し、
好ましくない。
また、架橋助剤としては、トリアリルンアヌレート、ト
リアリルイソノアヌレート、Ｎ、Ｎ’−ｍ〜フェニレン
ジマレイミドなどの水素受容基を有する化合物が用いら
れ、結晶性ポリオレフィン分子間の架橋反応に関し、架
橋反応を促進するためのらのである。この架橋助剤の配
合量は結晶性ポリオレフィン１００重量部に対して通常
０．３〜４重量部の範囲が好ましい。０．３重量部未満
てはこれらの添加の効果が十分に得られず、４重量部を
越えると過剰となり、架橋後の成形物の物性等に悪影響
を与えて不都合である。
また、上記光増感剤、紫外線吸収剤および架橋助剤以外
に、テトラキス−〔メチレン−３−（３°。
５″−ジ第３ブチル−４°−ヒドロキシフェニル）プロ
ピオネートコメタンなどの老化防止剤等の照射時の温度
条件下で透明性を損なわない添加剤、充填材を適宜配合
することができる。さらに、照射時の温度条件下で発泡
する４、４′オキンヒスｌ＼ンゼンスルホニルヒトラジ
）Ｓ、アゾジカルホンアミドなどの発泡剤を添加するこ
ともでき、これによれば発泡架橋成形物を製造すること
ができる。
また、結晶性ポリオレフィンと光増感剤との混合物ある
いは、これに紫外線吸収剤もしくはさらに架橋助剤か添
加された混合物の成形手段としては、従来から結晶性ポ
リオレフィンの成形に用いられている種々のものが適用
できる。成形物の形態がソートやフィルムあるいはチュ
ーブやパイプなどであれば通常の押出成形機による押出
成形が用いられる。また、成形物が電線やケーブルなど
の被覆物、例えば絶縁体やノースなとの場合には、クロ
スへラドダイを装着した押出機によろ押出被覆法やテー
プを巻回する方法などが用いられる。
さらに、通常の射出成形法によって成形物としてもよい
。ただし、形状が複雑な成形物では、紫外線照射時に結
晶融点以上に加熱されるため、その形状か崩れることに
なるため、適切ではないか、紫外線照射時において、紫
外線透過性を有しかっ耐熱性を有する材料、例えば石英
ガラスなどからなる型の内部に成形物を収容するなどの
方策を講ずれば、複雑な形状のものであってもよい。ま
１こ、成形品の肉厚は、形状がシート状のものでその両
面から紫外線照射か可能なものでは１０〜１５ｍｍか上
限となり、片面からのみの照射では５〜８ｍｍが上限と
なる。勿論、紫外線の強度（エネルギー密度）や照射時
間を大きく、長くすれば、さらに肉厚の成形物でもよい
が、結晶性ポリオレフィンの紫外線による劣化も同時に
進行するので注意が必要である。
次いで、このようにして得られた成形物をその結晶性ポ
リオレフィンの結晶融点以上の温度条件で紫外線を照射
する。
この温度条件は、原則として結晶融点以上とされるが、
好ましくはこの結晶融点よりも１０〜２０℃程度高い温
度とされる。しかし、あまりに高い温度では結晶性ポリ
オレフィンの熱劣化が進んで望ましくない。成形物が１
種以上の結晶性ポリオレフィンからなるものでは、その
温度条件を最も高い結晶融点以上とする。
また、紫外線の照射条件としては、波長が２００ｎｍ以
下でない線源を用いる。
そのためには、高圧水銀灯（波長域２５０〜６００ｎｍ
）やメタルハライド（波長域２００〜６００ｎｍ）が適
している。
本発明では、相対的に短波長側に紫外線スペクトルを多
くもつ高圧水銀灯と長波長側に紫外線スペクトルを多く
もつメタルハライドを併用するものである。
ま１こ、その強度（エネルギー密度）は、１０−４〜１
０−’（アインシュタイン／ｃｍ’・分）の範囲か望ま
しい。照射時間は、架橋密度、成形品の厚さなどによっ
て変わり、通常は１０〜６０秒程度であるか、この範囲
に限られるものでなく、例えば成形品の表面部のみを架
橋するものであれば、さらに短時間であってもよい。
さらに、成形物の形状かシートやフィルムなどの平板状
のものでは、その両面側に紫外線光源を配すれば肉厚の
成形物を短時間に架橋することができる。
また、電線、ケーブルなどの被覆物の場合には、その周
囲外方に光源を均一に配して、全外周部分に均一に照射
することもできる。また、銅などの金属導体直上に被覆
物を設けたものでは、金属導体表面か反射面として紫外
線を反射し、紫外線を効率よく利用することができる。
また、成形物の形状かチューブやバイブなどの中空の筒
状物の場合にはその外周部分から同様にして均一に照射
することかでき、中空部の内径が大きいときには中空部
内に紫外線光源を配置して内外側かう同時に照射しても
よい。さらに、押出成形機のダイの出口部分に接近して
紫外線光源を配置しておき、押出成形直後の結晶融点以
上の高温状態で直接紫外線を照射するようにしてもよい
。
このような条件での紫外線照射によって、例えばポリエ
チレンでは約９０％までの架橋密度を持つ程度にまで架
橋でき、また厚さか３ｍｍ程度のポリエチレンのシート
では１０〜３０秒で架橋が行なわれる。
架橋後の成形物は、自然空冷、水冷なとの冷却手段によ
って冷却されて架橋成形物となる。
このような架橋ポリオレフィン成形物の製法においては
、結晶性ポリオレフィンが完全に無定形で透明性が良好
な状態で紫外線の照射を受けるため、紫外線がよく吸収
かつ透過され、成形物の深部にまで到達して均一に架橋
か行われる。また、結晶融点以上となっているので、ポ
リマー分子の動きか活発となっており、架橋反応か一層
速やかに進行する。特に、光増感剤を添加することて、
その増感作用で光エネルギーの利用効率が向上し、架橋
反応か促進され、架橋助剤を添加したものでは活性基の
濃度が増加してポリマー分子鎖間の反応を促す二とにな
る。また、紫外線吸収剤の作用により、紫外線による結
晶性ポリオレフィン自体の光分解が最小限に抑えられ、
若干の架橋率の低下はあるものの光分解に伴う成形物の
着色や機械的強度等の低下か防止できる。
以下、具体例を示して作用効果を明確にする。At a temperature equal to or higher than the crystal melting point, all of the crystalline portions of the crystalline polyolefin are in a molten state, resulting in good transparency. Therefore, the transmission efficiency of ultraviolet rays is greatly improved, and the crosslinking efficiency is also increased. Here, the crosslinking efficiency by ultraviolet irradiation is first determined by the degree of light absorption of the irradiated object. Generally, light absorption is expressed by the following formula. A-ε・d-C A Absorption amount (dimensionless) ε. Molecular extinction coefficient of photosensitizer (1/mol/am) d Sample thickness (ca) C Initiator concentration (mol/I) As is clear from the above equation, if the sample thickness and initiator concentration are constant, the molecular absorption The larger the coefficient (ε), the larger the amount of absorption. This molecular extinction coefficient is a value specific to the substance; for example, for benzophenone, ε = 1890Q (λ = 252 n
m), ε=I56(λ-331 nm). Note that λ is the ultraviolet wavelength of the absorption peak. By the way, it is well known that the longer the wavelength of light such as ultraviolet rays, the greater the transmittance. Therefore, when crosslinking (polymerizing) a thick material, it is essential to absorb ultraviolet rays on the longer wavelength side. Second, in the case of ultraviolet irradiation crosslinking (polymerization), there is an oxygen inhibiting effect in the air, which inhibits crosslinking, so it is necessary to increase the crosslinking (polymerization) efficiency near the surface. The present invention solves the above problem by using a light source with a large amount of long wavelength ultraviolet spectrum and a light source with large amount of short wavelength ultraviolet spectrum. The present invention will be described in detail below. The crystalline polyolefin used in this invention includes:
Are there ethylene copolymers such as polyethylene, polypropylene, polybuteno-1, poly-4-methylpentene-1, ethylene-bupyrene copolymers, among others, low-density polyethylene, high-density polyethylene, linear polyethylene, Polyethylenes such as ultra-low density polyethylene and ultra-high molecular weight polyethylene are preferred because they have high crosslinking efficiency. Of course, a mixture of these may be used. This crystalline polyolefin is made into a molded product by various molding methods as a mixture with a photosensitizer. This mixture can be further mixed with a crosslinking aid or a crosslinking aid and an ultraviolet absorber to form a molded product. The photosensitizers used here include benzophenone,
Benzophenones such as 4-chlorobenzophenone, 2-chlorobenzophenone, 4,4"-dichlorohensiphenone, hexachlorobenzophenone, and 2-benzyl-
2-trimethylamino-I-(4-morpholinephenol)-butanone and chlorendic anhydrite,
"Sandry 1000J (trade name, manufactured by Monsando) etc. is used. The amount of this photosensitizer is 100% of crystalline polyolefin.
Preferably, 0.2 to 3 parts by weight are added to the parts by weight, preferably 0.2 parts by weight.
If it is less than 3 parts by weight, the effect of improving the crosslinking rate cannot be obtained, and if it exceeds 3 parts by weight, it is excessive and the electrical properties, mechanical properties, etc. of the molded product after crosslinking deteriorate, which is not preferable. By adding a photosensitizer, the crosslinking efficiency is significantly improved, making it possible to achieve a high level of crosslinking in a short period of time. However, as ultraviolet absorbers, salicylic acid derivatives such as phenyl salicylate, benzotriazoles such as l(2'-hydroquino-5-methylphenyl)benzotriazole, 2-hydroxybenzophenone, 2-hydroquine-4- Metquin benzophenone, 2-hydroquine-
Hydroxybenzophenones such as 4-octoquinohenzophenone, 2.2°-dihydroquino-4-methoquinophenone, and the like are preferably used. For example, phenyl salicylate) absorbs ultraviolet rays of 320n11 or less and is optimal. The amount of the ultraviolet absorber to be blended is determined in the range of 0.05 to 1 part by weight per 100 parts by weight of the crystalline polyolefin. If the amount is less than 0.005 parts by weight, the ability to prevent the deterioration of crystalline polyolefin during ultraviolet irradiation will be low, while if it exceeds 1 part by weight, it will be difficult to control ultraviolet deterioration. The degree of absorption into the agent increases, the crosslinking effect decreases,
Undesirable. In addition, as a crosslinking aid, a compound having a hydrogen accepting group such as triallyrunanurate, triallylisonoanurate, N,N'-m~phenylene dimaleimide is used, and it , to promote the cross-linking reaction. The amount of this crosslinking aid to be blended is preferably in the range of usually 0.3 to 4 parts by weight per 100 parts by weight of the crystalline polyolefin. If the amount is less than 0.3 parts by weight, the effect of these additions cannot be sufficiently obtained, and if it exceeds 4 parts by weight, it is excessive, which is disadvantageous because it adversely affects the physical properties of the molded product after crosslinking. In addition to the above-mentioned photosensitizers, ultraviolet absorbers, and crosslinking aids, aging agents such as tetrakis-[methylene-3-(3°.5″-di-tert-butyl-4°-hydroxyphenyl)propionate comethane, Additives and fillers that do not impair transparency under the temperature conditions during irradiation, such as inhibitors, can be appropriately blended.Furthermore, 4,4'-benzene sulfonyl hydroxide, which foams under the temperature conditions during irradiation, can be added as appropriate. It is also possible to add a foaming agent such as radi) S, azodicarbonamide, etc., and with this, a foamed crosslinked molded product can be produced.Also, a mixture of a crystalline polyolefin and a photosensitizer or a mixture thereof Various methods conventionally used for molding crystalline polyolefins can be used as a molding method for the mixture in which a UV absorber or a crosslinking aid is added.The shape of the molded product may be sorted, film, tube, or For pipes, etc., extrusion molding using a normal extrusion molding machine is used.Also, when the molded product is a covering such as an electric wire or cable, such as an insulator or a north, an extrusion machine equipped with a cross-to-rad die is used. A method such as extrusion coating or winding a tape is used.Furthermore, a molded product may be made using a normal injection molding method.However, if the shape is complex, the molded product may be heated above the crystal melting point during ultraviolet irradiation. It may not be appropriate to place the molded product inside a mold made of a material that is transparent to UV rays and has heat resistance, such as quartz glass, during UV irradiation. If the following measures are taken, it is possible to have a complex shape.Also, the wall thickness of the molded product is 10 to 15 mm if it is sheet-like and can be irradiated with ultraviolet rays from both sides. The upper limit is 5 to 8 mm when irradiated only from one side.Of course, if the intensity (energy density) of the ultraviolet rays and the irradiation time are increased and the irradiation time is increased, a thicker molded product can be obtained, but Care must be taken as deterioration due to ultraviolet rays also progresses at the same time. Next, the molded product thus obtained is irradiated with ultraviolet rays at a temperature higher than the crystalline melting point of the crystalline polyolefin. In principle, this temperature condition is Although it is said to be above the crystal melting point,
Preferably, the temperature is about 10 to 20°C higher than the crystal melting point. However, too high a temperature is undesirable because thermal deterioration of the crystalline polyolefin progresses. 1 molded item
In the case of a crystalline polyolefin containing more than one seed, the temperature condition is set to be equal to or higher than the highest crystal melting point. Further, as the ultraviolet irradiation conditions, a radiation source with a wavelength not less than 200 nm is used. For this purpose, a high-pressure mercury lamp (wavelength range 250-600nm) is required.
) and metal halides (wavelength range 200 to 600 nm) are suitable. In the present invention, a high-pressure mercury lamp having a relatively large ultraviolet spectrum on the short wavelength side and a metal halide having a large ultraviolet spectrum on the long wavelength side are used in combination. Well, its strength (energy density) is 10-4 to 1
A range of 0-'(Einstein/cm'·min) is desirable. The irradiation time varies depending on the crosslinking density, the thickness of the molded product, etc., and is usually about 10 to 60 seconds, but is not limited to this range. For example, if only the surface of the molded product is crosslinked. , it may be even shorter. Furthermore, if the molded product is in the form of a flat plate such as a sheet or film, a thick molded product can be crosslinked in a short time by placing ultraviolet light sources on both sides of the molded product. Further, in the case of a covered object such as an electric wire or cable, the light source can be uniformly arranged outside the periphery of the covered object, so that the entire outer periphery can be uniformly irradiated. Further, in the case where a coating is provided directly on a metal conductor such as copper, the surface of the metal conductor acts as a reflective surface to reflect ultraviolet rays, and the ultraviolet rays can be efficiently utilized. In addition, in the case of molded objects or hollow cylindrical objects such as tubes and vibrators, it is possible to uniformly irradiate from the outer periphery in the same way, and if the inner diameter of the hollow part is large, the ultraviolet light source can be placed inside the hollow part. It is also possible to irradiate the inside and outside at the same time. Furthermore, an ultraviolet light source may be placed close to the exit portion of the die of the extrusion molding machine, and the ultraviolet light source may be directly irradiated with ultraviolet light at a high temperature equal to or higher than the crystal melting point immediately after extrusion. By irradiating ultraviolet rays under such conditions, for example, polyethylene can be crosslinked to a degree with a crosslinking density of up to about 90%, and a polyethylene sheet with a thickness of about 3 mm can be crosslinked in 10 to 30 seconds. The molded product after crosslinking is cooled by cooling means such as natural air cooling or water cooling to become a crosslinked molded product. In this method of manufacturing cross-linked polyolefin molded products, the crystalline polyolefin is completely amorphous and has good transparency when it is irradiated with ultraviolet rays, so the ultraviolet rays are well absorbed and transmitted, reaching deep into the molded material. crosslinking is carried out uniformly. In addition, since the temperature is above the crystal melting point, the movement of polymer molecules becomes active, and the crosslinking reaction proceeds more quickly. In particular, by adding a photosensitizer,
Its sensitizing effect improves the utilization efficiency of light energy and promotes the crosslinking reaction, and when a crosslinking aid is added, the concentration of active groups increases and the reaction between polymer molecular chains is promoted. In addition, due to the action of the ultraviolet absorber, photodecomposition of the crystalline polyolefin itself due to ultraviolet rays is minimized,
Although there is a slight decrease in the crosslinking rate, it is possible to prevent coloring of the molded product and decrease in mechanical strength due to photodecomposition. Hereinafter, specific examples will be shown to clarify the effects.
メルトインデックス（Ｍ Ｉ ＞かｌの低密度ポリエチ
レン１００重量部に対し、光増感剤として４−クロロヘ
ンシフエノンを１重量部、架橋助剤としてトリアリルイ
ソノアヌレ−８１重量部添加し、断面積］ ００ ｍｍ
”の導体上に押出様により１６０℃の温度で絶縁体を厚
さ３ＩｌｌＩｎに被覆した。
押出被覆後、絶縁体温度が１５０℃以上に保持されてい
る条件下で紫外Ｓ照射した。この際の紫外線照射は、高
圧水銀灯（１２０ｗ／ｃｍ）を０〜１０秒、メタルハラ
イド灯（１２０Ｗ／ ｃｉ＋）を０〜１０秒とした。
紫外線照射後、冷却槽に導き、絶縁電線を得た。
得られた各絶縁電線の内層、中層、外層の各架橋度を調
べ、結果を第１表に示した。
以 下 余 白
第 Ｉ 表
八 Ｂ 架橋度（％）・
１（秒）：（秒）、内層沖層外層□
； ０ミ ｏｌｏｌｏ”０□□
ｉ ０ ： ５ ・７０．３０’Ｉ Ｏ’１０１１
Ｏ’、８５１７０１４０
１５１１１１１Ｏ：ｌ０１１４計８０・：、 ５： ５
・８０，８０．８０
１ ５１１０１８５・８計：８０
１ ′
：、１０．０：１０５０・、８５
ゴ１０１□ ５）８０□８０□８５゜
Ａ：高圧水銀灯
Ｂ：メタルハライド灯
第１表の結果から、高圧水銀灯とメタル／）ライド灯か
らなる紫外線スペクトルの最多波長領域の異なる紫外線
を光源に併用することで、内層、中層、外層共に均一な
架橋度の絶縁体を得ることができることが認められる。To 100 parts by weight of low-density polyethylene with a melt index (M I > kl, 1 part by weight of 4-chlorohensiphenone as a photosensitizer and 81 parts by weight of triallylisonoanule as a crosslinking aid were added, Cross-sectional area] 00 mm
An insulator was coated on the conductor by extrusion to a thickness of 3 IllIn at a temperature of 160°C. After extrusion coating, the insulator was irradiated with ultraviolet S under the condition that the insulator temperature was maintained at 150°C or higher. Ultraviolet irradiation was carried out using a high-pressure mercury lamp (120 W/cm) for 0 to 10 seconds and a metal halide lamp (120 W/ci+) for 0 to 10 seconds. After ultraviolet irradiation, the wire was guided to a cooling tank to obtain an insulated wire. The degree of crosslinking of the inner layer, middle layer, and outer layer of each insulated wire was investigated, and the results are shown in Table 1. Table 8 B Crosslinking degree (%) 1 (seconds): (seconds), inner layer Outer offshore layer □ ; 0 mi ololo"0 □□ i 0: 5 ・70.30'I O'1011
O', 85170140 1511111O:l0114 total 80・:, 5: 5
・80, 80.80 1 5110185・8 total: 80 1 ′ :, 10.0: 1050・, 85 go 101□ 5) 80□80□85°A: High pressure mercury lamp B: Metal halide lamp From the results in Table 1 It has been found that by using ultraviolet rays with different maximum wavelength regions of the ultraviolet spectrum as light sources, such as a high-pressure mercury lamp and a metal/)ride lamp, it is possible to obtain an insulator with a uniform degree of crosslinking in the inner, middle, and outer layers.
以上説明したように、本発明の架橋ポリオレフィン成形
物の製法は、結晶性ポリオレフィンからなる成形物に、
その結晶性ポリオレフィンの結晶融点以上の温度条件で
、波長の異なる多種類の紫外線を照射するものであるの
で、肉厚のポリオレフィン成形物に対しても効率よく、
その深部まで均一に高い架橋密度で、短時間で架橋させ
ることができる。As explained above, the method for producing a crosslinked polyolefin molded product of the present invention includes forming a molded product made of crystalline polyolefin.
Since it irradiates multiple types of ultraviolet rays with different wavelengths at a temperature higher than the crystal melting point of the crystalline polyolefin, it is efficient even for thick polyolefin moldings.
Crosslinking can be carried out uniformly and at a high crosslinking density deep within a short period of time.
Claims (7)
ィンの結晶融点以上の温度条件で、波長の異なる多種類
の紫外線を照射することを特徴とする架橋ポリオレフィ
ン成形物の製法。(1) A method for producing a crosslinked polyolefin molded product, which comprises irradiating a crystalline polyolefin with various kinds of ultraviolet rays having different wavelengths at a temperature equal to or higher than the crystalline melting point of the crystalline polyolefin.
に、その結晶性ポリオレフィンの結晶融点以上の温度条
件で、波長の異なる多種類の紫外線を照射することを特
徴とする架橋ポリオレフィン成形物の製法。(2) A crosslinked polyolefin molded product, which is characterized in that a molded product made of a crystalline polyolefin and a photosensitizer is irradiated with multiple types of ultraviolet rays with different wavelengths at a temperature higher than the crystalline melting point of the crystalline polyolefin. Manufacturing method.
なる成形物に、その結晶性ポリオレフィンの結晶融点以
上の温度条件で、波長の異なる多種類の紫外線を照射す
ることを特徴とする架橋ポリオレフィン成形物の製法。(3) Crosslinking characterized by irradiating a molded product consisting of a crystalline polyolefin, a photosensitizer, and a crosslinking aid with multiple types of ultraviolet rays of different wavelengths at a temperature higher than the crystal melting point of the crystalline polyolefin. Manufacturing method for polyolefin molded products.
橋ポリオレフィン成形物の製法において、紫外線照射に
用いる光源が高圧水銀灯とメタルハライド灯であること
を特徴とする架橋ポリオレフィン成形物の製法。(4) The method for producing a crosslinked polyolefin molded product according to any one of claims (1) to (3), wherein the light source used for ultraviolet irradiation is a high-pressure mercury lamp and a metal halide lamp. .
１）ないし（４）のいずれかに記載の架橋ポリオレフィ
ン成形物の製法。(5) Claim in which the molded product is a covering for electric wires or cables (
1) The method for producing a crosslinked polyolefin molded product according to any one of (4).
求項（１）ないし（４）のいずれかに記載の架橋ポリオ
レフィン成形物の製法。(6) The method for producing a crosslinked polyolefin molded product according to any one of claims (1) to (4), wherein the molded product is a cylindrical object such as a tube or a pipe.
ある請求項（１）ないし（４）のいずれかに記載の架橋
ポリオレフィン成形物の製法。(7) The method for producing a crosslinked polyolefin molded product according to any one of claims (1) to (4), wherein the molded product is in the form of a flat plate such as a film or a notebook.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2317459A JPH04185651A (en) | 1990-11-21 | 1990-11-21 | Production of crosslinked polyolefin molding |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2317459A JPH04185651A (en) | 1990-11-21 | 1990-11-21 | Production of crosslinked polyolefin molding |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04185651A true JPH04185651A (en) | 1992-07-02 |
Family
ID=18088464
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2317459A Pending JPH04185651A (en) | 1990-11-21 | 1990-11-21 | Production of crosslinked polyolefin molding |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04185651A (en) |
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0722973A1 (en) * | 1995-01-20 | 1996-07-24 | The University Of Southern California | Chemically crosslinked ultrahigh molecular weight polyethylene for artificial human joints |
| WO1997029793A1 (en) * | 1996-02-13 | 1997-08-21 | Massachusetts Institute Of Technology | Radiation and melt treated ultra high molecular weight polyethylene prosthetic devices |
| US5879400A (en) * | 1996-02-13 | 1999-03-09 | Massachusetts Institute Of Technology | Melt-irradiated ultra high molecular weight polyethylene prosthetic devices |
| US6228900B1 (en) | 1996-07-09 | 2001-05-08 | The Orthopaedic Hospital And University Of Southern California | Crosslinking of polyethylene for low wear using radiation and thermal treatments |
| US6245276B1 (en) | 1999-06-08 | 2001-06-12 | Depuy Orthopaedics, Inc. | Method for molding a cross-linked preform |
| US6562540B2 (en) | 1996-10-02 | 2003-05-13 | Depuy Orthopaedics, Inc. | Process for medical implant of cross-linked ultrahigh molecular weight polyethylene having improved balance of wear properties and oxidation resistance |
| US6627141B2 (en) | 1999-06-08 | 2003-09-30 | Depuy Orthopaedics, Inc. | Method for molding a cross-linked preform |
| US6692679B1 (en) | 1998-06-10 | 2004-02-17 | Depuy Orthopaedics, Inc. | Cross-linked molded plastic bearings |
| US6786933B2 (en) | 1996-02-13 | 2004-09-07 | The General Hospital Corporation | Radiation and melt treated ultra high molecular weight polyethylene prosthetic devices |
| US6818172B2 (en) | 2000-09-29 | 2004-11-16 | Depuy Products, Inc. | Oriented, cross-linked UHMWPE molding for orthopaedic applications |
| US7169186B2 (en) | 2000-07-31 | 2007-01-30 | Massachusetts General Hospital | Monopolar constrained acetabular component |
| US7819925B2 (en) | 2002-01-28 | 2010-10-26 | Depuy Products, Inc. | Composite prosthetic bearing having a crosslinked articulating surface and method for making the same |
| US7938861B2 (en) | 2003-04-15 | 2011-05-10 | Depuy Products, Inc. | Implantable orthopaedic device and method for making the same |
| JP2016518498A (en) * | 2013-05-03 | 2016-06-23 | ウポノール・イノベーション・エービーＵｐｏｎｏｒ Ｉｎｎｏｖａｔｉｏｎ Ａｂ | Polyolefin pipe |
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-
1990
- 1990-11-21 JP JP2317459A patent/JPH04185651A/en active Pending
Cited By (22)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6281264B1 (en) | 1995-01-20 | 2001-08-28 | The Orthopaedic Hospital | Chemically crosslinked ultrahigh molecular weight polyethylene for artificial human joints |
| EP0722973A1 (en) * | 1995-01-20 | 1996-07-24 | The University Of Southern California | Chemically crosslinked ultrahigh molecular weight polyethylene for artificial human joints |
| US6786933B2 (en) | 1996-02-13 | 2004-09-07 | The General Hospital Corporation | Radiation and melt treated ultra high molecular weight polyethylene prosthetic devices |
| US5879400A (en) * | 1996-02-13 | 1999-03-09 | Massachusetts Institute Of Technology | Melt-irradiated ultra high molecular weight polyethylene prosthetic devices |
| US6464926B1 (en) | 1996-02-13 | 2002-10-15 | The General Hospital Corporation | Process of making ultra high molecular weight polyethylene prosthetic devices |
| WO1997029793A1 (en) * | 1996-02-13 | 1997-08-21 | Massachusetts Institute Of Technology | Radiation and melt treated ultra high molecular weight polyethylene prosthetic devices |
| US8865788B2 (en) | 1996-02-13 | 2014-10-21 | The General Hospital Corporation | Radiation and melt treated ultra high molecular weight polyethylene prosthetic devices |
| US6228900B1 (en) | 1996-07-09 | 2001-05-08 | The Orthopaedic Hospital And University Of Southern California | Crosslinking of polyethylene for low wear using radiation and thermal treatments |
| US6562540B2 (en) | 1996-10-02 | 2003-05-13 | Depuy Orthopaedics, Inc. | Process for medical implant of cross-linked ultrahigh molecular weight polyethylene having improved balance of wear properties and oxidation resistance |
| US6692679B1 (en) | 1998-06-10 | 2004-02-17 | Depuy Orthopaedics, Inc. | Cross-linked molded plastic bearings |
| US6245276B1 (en) | 1999-06-08 | 2001-06-12 | Depuy Orthopaedics, Inc. | Method for molding a cross-linked preform |
| US6627141B2 (en) | 1999-06-08 | 2003-09-30 | Depuy Orthopaedics, Inc. | Method for molding a cross-linked preform |
| US8608806B2 (en) | 2000-07-31 | 2013-12-17 | The General Hospital Corporation | Monopolar constrained acetabular component |
| US7169186B2 (en) | 2000-07-31 | 2007-01-30 | Massachusetts General Hospital | Monopolar constrained acetabular component |
| US9060865B2 (en) | 2000-07-31 | 2015-06-23 | The General Hospital Corporation | Monopolar constrained acetabular component |
| US6818172B2 (en) | 2000-09-29 | 2004-11-16 | Depuy Products, Inc. | Oriented, cross-linked UHMWPE molding for orthopaedic applications |
| US7819925B2 (en) | 2002-01-28 | 2010-10-26 | Depuy Products, Inc. | Composite prosthetic bearing having a crosslinked articulating surface and method for making the same |
| US7938861B2 (en) | 2003-04-15 | 2011-05-10 | Depuy Products, Inc. | Implantable orthopaedic device and method for making the same |
| JP2016518498A (en) * | 2013-05-03 | 2016-06-23 | ウポノール・イノベーション・エービーＵｐｏｎｏｒ Ｉｎｎｏｖａｔｉｏｎ Ａｂ | Polyolefin pipe |
| WO2019148407A1 (en) * | 2018-02-01 | 2019-08-08 | Dow Global Technologies Llc | Masterbatch with semi-crystalline polyolefin carrier resin |
| JP2021517594A (en) * | 2018-02-01 | 2021-07-26 | ダウ グローバル テクノロジーズ エルエルシー | Masterbatch with semi-crystalline polyolefin carrier resin |
| US11952470B2 (en) | 2018-02-01 | 2024-04-09 | Dow Global Technologies Llc | Masterbatch with semi-crystalline polyolefin carrier resin |
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