【発明の詳細な説明】[Detailed description of the invention]
本発明は流体移送用熱硬化性樹脂管に関するも
のである。
従来、水、油その他の液状物質や、空気、ガス
等の気体を移送するための流体移送管としては金
属管やポリ塩化ビニル等の熱可塑性樹脂管が使用
されている。
金属管は強固であるが重くて施工性に劣り、腐
蝕性などの問題があり、また耐熱性および耐炎性
にはすぐれているものの断熱性に乏しく、火炎の
場合には管内部の流体及び管の支持体或は周辺へ
高熱を伝達し、火炎蔓延の原因となる恐れがあ
る。また、熱可塑性樹脂管は、軽量で耐腐蝕性を
有し、安価でもあるが耐熱、耐炎性に劣ることは
周知のことである。
そこで、耐熱性、耐炎性、耐腐蝕性、断熱性等
に富む熱硬化性樹脂管をこの用途に提供すること
が考えられるが、従来の成形法では高価なものと
なり物性的にも問題があるためこの用途には実用
されていない。
即ち、熱硬化性樹脂の長尺管はプランジヤー押
出成形法により成形されるのが一般的であるが、
この成形法に於ては金型部における押出圧力が高
く、しかも間欠押出であるため均一な成形物を得
ることが困難であり、また生産性も低い。
かかる事情からダイスとスクリユー押出機を用
いる成形法も開発されているが、装置内における
樹脂の滞留が起りやすく、従つて局部的に硬化反
応が進行したり、僅かな圧力や温度の変化で硬化
反応が急激に進行するなどの問題があり、連続し
て安定な成形を行なうことが困難であつた。ま
た、前記したいずれの方法に於ても管の円周方向
の強度が低いものしか得られず、その結果内外圧
に対して弱く且つ衝撃に対しては管の軸方向に割
れやすい等の実用上の問題があつた。これは従来
の押出法では、樹脂自体及び繊維状充填物などが
押出方向、すなわち管の軸方向に配向するためと
考えられる。
すなわち、溶融した樹脂が金型内へ導びかれ金
型内の流路に沿つて移動する間に賦形および硬化
が進行するため、その間の樹脂の移動方向は押出
方向、すなわち管軸方向のみとなり樹脂及び繊維
状充填物などがその方向へ配向するためと考えら
れる。
本発明者らは、これらの欠点を解決すると共に
耐熱性、耐炎性、耐腐蝕性を有し、軽量かつ安価
な流体移送用樹脂管を提供すべく種々検討を行な
つた結果、先端部に平滑部を有するスクリユーを
使用し、平滑部に於て押出後自己形状を保持でき
る程度にまで賦形することによりこの目的が達成
されることを見出して本発明に到達した。
即ち本発明は先端部に平滑部を有するスクリユ
ーを使用し平滑部に於て押出後自己形状を保持で
きる程度にまで賦形することにより成形された流
体移送用熱硬化性樹脂管である。
本発明の熱硬化性樹脂管は、例えば特願昭58−
51526に記載した方法により製造されるが、この
製造法の特徴は平滑部を有するスクリユーを使用
し平滑部に於て押出後自己形状を保持できる程度
にまで賦形硬化させることにあり、この方法によ
り従来押出成形が困難であつた熱硬化性樹脂管を
生産性良く安価に製造することができる。
すなわち押出機内に投入された熱硬化性樹脂材
料はスクリユー供給部から圧縮部を移行する間に
加熱溶融され計量部を経て計量部のフライト先端
部よりラセン状で平滑部に移行し、そこでシリン
ダー内壁との摩擦抵抗により、スクリユーフライ
トによつて生ずる間隙部分が狭められついには圧
融着される。ついで樹脂は平滑部を移行する間に
賦形硬化されてシリンダー先端より連続した管と
なつて押出される。この間樹脂は供給部から計量
部に至る間はスクリユー溝に沿つた方向にせん断
を受けながら移行し、樹脂自体および繊維状充填
物等は管の押出方向に対し特に定まつた方向へは
配向することなく不規則な方向へ配向し、平滑部
へ移行した後硬化が進むためそのまゝの状態が固
定され、その結果として樹脂自体および繊維状充
填物等は管の軸方向と円周方向にバランス良く配
向され、得られる管の軸方向及び管軸に対して直
角方向における圧縮強度のバランスが良くなるも
のと考えられる。
後述の第１表に管軸に対し直角方向の圧縮強度
(A)と管軸方向の圧縮強度(B)及び／Ａ／Ｂの比並び
に水圧試験結果を記載した。
この表からも容易に理解されるとおり、従来法
による管はＡ／Ｂの比が0.37と小さく、縦割れを
生じやすいのに比べ、本発明の管はＡ／Ｂの比が
0.4〜1.5と大きく縦割れを生ずることなく、内圧
に対しても強いことがわかる。
本発明に於て管軸方向の圧縮強度とは、JIS−
Ｋ−6911の５，19，５頁による試験（圧縮強度試
験）を行ない管が破壊（亀裂が入つた場合も含
む）した時の強さを表わし、管軸に対し直角方向
の圧縮強度とはJIS、Ｋ 6741の５，６項による
試験（へん平試験）を行なつて管が破壊した時の
強さを表わす。
本発明に使用される熱硬化性樹脂としては、フ
エノール樹脂、メラミン樹脂、キシレン樹脂、尿
素樹脂、不飽和ポリエステル樹脂、エポキシ樹
脂、シリコン樹脂、アリル樹脂、アニリン樹脂等
が挙げられ、特にフエノール樹脂、メラミン樹
脂、キシレン樹脂の使用が好適である。
本発明に用いられる熱硬化性樹脂には、必要に
応じて熱硬化性樹脂の成形に於て一般に用いられ
る充填剤、離型剤、増粘剤、着色剤、分散剤、離
燃剤、発泡剤、重合開始剤、硬化促進剤、重合禁
止剤などを添加することができる。また更に他種
のポリマーあるいは有機または無機の繊維状物、
例えば硝子繊維等を加えることもできる。
これら熱硬化性樹脂による流体移送用管は、耐
熱性に優れると共に重油、ガソリン、灯油等の油
類、アルコール、ケトン、エステル類、芳香族炭
化水素等の有機溶剤、酸、アルカリになどに対し
て耐性を有するのみならず、成形材料として特に
フエノール樹脂、メラミン樹脂、キシレン樹脂等
を使用することにより、火炎にさらされても延焼
しない、ドロツピングを起さない、原形をほゞ維
持する、有毒ガスを発生しない等の優れた耐炎特
性を有する。
本発明の方法により製造された管は、耐熱性、
耐炎性、耐腐蝕性、耐薬品性を有するのみなら
ず、本製造方法の特長として管の成形時に樹脂或
は繊維状充填物が管の押出方向と円周方向にバラ
ンス良く配向するためめ、管の押出方向及びそれ
に垂直な方向の強度のバランスが良く、耐圧性に
優れたものとなり、流体移送管に好適である。
本発明の熱硬化性樹脂管の用途を具体的に説明
すれば、液体移送用として一般住宅やビル、工場
あるいは温泉などの給水管、給湯管、排水管（例
えば風呂、湯沸し器、クーラー、ソーラーシステ
ム等の給排水管、一般排水管等）、工場、車輌、
船舶、航空機等の給排油管、薬品移送管などが挙
げられる。
また気体移送用としては、一般住宅やビル、工
場等の送気管、通気管、排気管（例えば、ガスレ
ンジ、ストーブ、内燃機関の送気管、排気管、一
般通気管、一般送気管、一般排気管等）、化学工
場の気体（例えばチツソ、アルゴン、ヘリウム
等）の移送管などが挙げられる。
以下、製造例により本発明を更に説明する。
製造例 １
口径30mm、Ｌ／Ｄ＝22の押出機により、スクリ
ユー底部の径が25mmの計量部に続く先端部に径が
25mm長さが120mm（4D）の平滑部を有する圧縮比
が2.3のスクリユーを用い、成形材料としてフエ
ノール樹脂（日本オイルシール(株)製、商品名ロジ
ヤースRX−6684）を使用してパイプを押出成形
した。
シリンダー各部の温度は
C1（ ０ 〜 2D）…水冷
C2（ 3D〜10D）…80℃
C3（11D〜18D）…100℃
C4（19D〜22D）…120℃
に設定し、スクリユー回転数35rpmの条件で押出
成形を行なつて外径30mm、肉厚2.5mmのパイプを
得た。
製造例 ２
製造例１と同じ押出装置を使用して成形材料を
してフエノール樹脂（松下電工(株)製、商品名CN
−4610）を用い、パイプを押出成形した。シリン
ダー各部の温度はC1＝水冷、C2＝80℃、C3＝110
℃、C4＝120℃に設定し、スクリユー回転数
35rpmの条件で押出成形を行なつて、外径30mm、
肉厚2.5mmのパイプを得た。
製造例 ３
製造例１と同じ押出装置を用い、成形材料とし
てフエノール樹脂（住友ベークライト(株)製、商品
名PM−795J）を用いてパイプを押出成形した。
シリンダー各部の温度はC1＝水冷、C2＝75℃、
C3＝105℃、C4＝120℃に設定し、スクリユー回
転数35rpmで押出成形を行なつて外径30mm、肉厚
2.5mmのパイプを得た。
製造例 ４
製造例１と同じ押出装置を用い、成形材料とし
てメラミン−フエノール樹脂（松下電工(株)製、商
品名ME−Ａ）を使用してパイプを押出成形し
た。シリンダー各部の温度はC1＝水冷、C2＝90
℃、C3＝120℃、C4＝130℃に設定し、スクリユ
ー回転数35rpmで押出成形を行なつて外径30mm肉
厚2.5mmのパイプを得た。
各製造所にて得られたパイプの性能は第１表及
び第２表に示したとおりであつた。これらの結果
から、本発明の熱硬化性樹脂管は管軸方向と管軸
に直角な方向の強度のバランスが良く内圧に対し
強く且つ耐熱性、耐燃性、耐薬品性にも優れてい
ることがわかる。
The present invention relates to a thermosetting resin tube for fluid transfer. Conventionally, metal pipes and thermoplastic resin pipes such as polyvinyl chloride have been used as fluid transfer pipes for transporting water, oil, and other liquid substances, and air, gas, and other gases. Although metal pipes are strong, they are heavy, have poor workability, and have problems such as corrosion, and although they have excellent heat resistance and flame resistance, they have poor insulation properties, and in the case of a flame, the fluid inside the pipe and the pipe may transfer high heat to the supporting body or the surrounding area, causing the spread of flame. Furthermore, it is well known that thermoplastic resin pipes are lightweight, have corrosion resistance, and are inexpensive, but are inferior in heat resistance and flame resistance. Therefore, it is possible to provide thermosetting resin pipes with high heat resistance, flame resistance, corrosion resistance, heat insulation properties, etc. for this purpose, but conventional molding methods are expensive and have physical problems. Therefore, it has not been put into practical use for this purpose. That is, long tubes of thermosetting resin are generally formed by plunger extrusion, but
In this molding method, the extrusion pressure in the mold section is high and intermittent extrusion is used, so it is difficult to obtain a uniform molded product and the productivity is low. For this reason, a molding method using a die and screw extruder has been developed, but the resin tends to stagnate inside the equipment, resulting in the curing reaction progressing locally or curing due to slight changes in pressure or temperature. There were problems such as the rapid progress of the reaction, making it difficult to perform continuous and stable molding. In addition, in any of the above-mentioned methods, only a pipe with low strength in the circumferential direction can be obtained, and as a result, it is weak against internal and external pressure and easily cracks in the axial direction when subjected to impact. I had the above problem. This is thought to be because in conventional extrusion methods, the resin itself and the fibrous filler are oriented in the extrusion direction, that is, in the axial direction of the tube. In other words, shaping and curing progress while the molten resin is guided into the mold and moves along the flow path in the mold, so the only direction of movement of the resin during that time is in the extrusion direction, that is, in the tube axis direction. This is thought to be because the resin, fibrous filler, etc. are oriented in that direction. The inventors of the present invention have conducted various studies in order to solve these drawbacks and provide a resin pipe for fluid transfer that is heat resistant, flame resistant, corrosion resistant, lightweight, and inexpensive. The present invention was achieved by discovering that this object can be achieved by using a screw having a smooth portion and shaping the material to the extent that it can maintain its own shape after extrusion in the smooth portion. That is, the present invention is a thermosetting resin tube for fluid transfer which is formed by using a screw having a smooth portion at the tip and shaping the tube to the extent that it can maintain its own shape after extrusion in the smooth portion. The thermosetting resin pipe of the present invention can be used, for example, in Japanese Patent Application No.
51526, the feature of this manufacturing method is that a screw with a smooth part is used and the smooth part is shaped and hardened to the extent that it can maintain its own shape after extrusion. This makes it possible to manufacture thermosetting resin pipes, which have conventionally been difficult to extrude, with good productivity and at low cost. In other words, the thermosetting resin material fed into the extruder is heated and melted while moving from the screw supply section to the compression section, passes through the metering section, and moves from the tip of the flight of the metering section to the smooth section in a helical shape, where it forms the inner wall of the cylinder. Due to the frictional resistance, the gap created by the screw flight is narrowed and finally pressure fused. The resin is then shaped and hardened while traveling through the smooth section, and is extruded from the tip of the cylinder in the form of a continuous tube. During this time, the resin transfers while being subjected to shear in the direction along the screw groove from the supply section to the metering section, and the resin itself and the fibrous filler are oriented in a particular direction with respect to the extrusion direction of the tube. The resin itself and the fibrous filler etc. are oriented in an irregular direction without being oriented in the axial direction and the circumferential direction of the pipe. It is considered that the tubes are oriented in a well-balanced manner, and the resulting tube has a good balance of compressive strength in the axial direction and in the direction perpendicular to the tube axis. Table 1 below shows the compressive strength in the direction perpendicular to the tube axis.
(A), the compressive strength in the tube axis direction (B), the ratio of /A/B, and the results of the water pressure test are listed. As can be easily understood from this table, the pipe made by the conventional method has a small A/B ratio of 0.37 and is prone to vertical cracking, whereas the pipe of the present invention has a low A/B ratio.
It can be seen that it is resistant to internal pressure with a value of 0.4 to 1.5 without causing large vertical cracks. In the present invention, the compressive strength in the tube axis direction is defined as JIS-
The test (compressive strength test) according to pages 5, 19, and 5 of K-6911 indicates the strength when the pipe is broken (including cracks), and the compressive strength in the direction perpendicular to the pipe axis is This indicates the strength of the pipe when it breaks when tested in accordance with sections 5 and 6 of JIS K 6741 (flattening test). Thermosetting resins used in the present invention include phenolic resins, melamine resins, xylene resins, urea resins, unsaturated polyester resins, epoxy resins, silicone resins, allyl resins, aniline resins, etc. In particular, phenolic resins, Melamine resin and xylene resin are preferably used. The thermosetting resin used in the present invention includes fillers, mold release agents, thickeners, colorants, dispersants, flame release agents, and blowing agents that are generally used in the molding of thermosetting resins, as necessary. , a polymerization initiator, a curing accelerator, a polymerization inhibitor, etc. can be added. Furthermore, other types of polymers or organic or inorganic fibrous materials,
For example, glass fibers etc. can also be added. Fluid transfer pipes made of these thermosetting resins have excellent heat resistance and are resistant to oils such as heavy oil, gasoline and kerosene, organic solvents such as alcohol, ketones, esters, and aromatic hydrocarbons, acids, and alkalis. By using phenolic resin, melamine resin, xylene resin, etc. as the molding material, it does not spread, does not drop, and almost maintains its original shape even when exposed to flame. It has excellent flame resistance such as not emitting poisonous gas. The tube produced by the method of the present invention has heat resistance,
In addition to having flame resistance, corrosion resistance, and chemical resistance, this manufacturing method is characterized by the fact that the resin or fibrous filler is oriented in a well-balanced manner in the extrusion direction and circumferential direction of the tube during tube molding. The tube has a good balance of strength in the extrusion direction and the direction perpendicular to it, and has excellent pressure resistance, making it suitable for fluid transfer tubes. More specifically, the thermosetting resin pipe of the present invention can be used for liquid transfer in general houses, buildings, factories, hot springs, etc., such as water supply pipes, hot water supply pipes, and drainage pipes (for example, baths, water heaters, air conditioners, solar panels, etc.). water supply and drainage pipes for systems, general drainage pipes, etc.), factories, vehicles,
Examples include oil supply and drainage pipes for ships and aircraft, and chemical transfer pipes. In addition, for gas transfer, air pipes, ventilation pipes, exhaust pipes of general houses, buildings, factories, etc. (for example, gas ranges, stoves, internal combustion engine air pipes, exhaust pipes, general ventilation pipes, general air supply pipes, general exhaust pipes, pipes, etc.), gas transfer pipes for chemical factories (e.g. nitrogen, argon, helium, etc.). The present invention will be further explained below with reference to production examples. Manufacturing example 1 Using an extruder with a diameter of 30 mm and L/D = 22, the screw bottom has a diameter of 25 mm at the tip that follows the measuring section.
A pipe is extruded using a screw with a compression ratio of 2.3, which has a smooth part of 25 mm length and 120 mm (4D), and uses phenol resin (manufactured by Nippon Oil Seal Co., Ltd., trade name Logiyas RX-6684) as the molding material. Molded. The temperature of each part of the cylinder was set to C1 (0 to 2D)...water cooling C2 (3D to 10D)...80℃ C3 (11D to 18D)...100℃ C4 (19D to 22D)...120℃, and the screw rotation. Extrusion molding was performed at several 35 rpm to obtain a pipe with an outer diameter of 30 mm and a wall thickness of 2.5 mm. Production Example 2 Using the same extrusion equipment as Production Example 1, the molding material was molded into phenolic resin (manufactured by Matsushita Electric Works Co., Ltd., product name CN).
-4610) was used to extrude the pipe. The temperature of each part of the cylinder is C 1 = water cooling, C 2 = 80℃, C 3 = 110
℃, C 4 = 120℃, screw rotation speed
Extrusion molding was carried out under the conditions of 35 rpm, and the outer diameter was 30 mm.
A pipe with a wall thickness of 2.5 mm was obtained. Production Example 3 Using the same extrusion apparatus as in Production Example 1, a pipe was extrusion-molded using phenol resin (manufactured by Sumitomo Bakelite Co., Ltd., trade name PM-795J) as a molding material. The temperature of each part of the cylinder is C 1 = water cooling, C 2 = 75℃,
Setting C 3 = 105℃ and C 4 = 120℃, extrusion molding was performed at a screw rotation speed of 35 rpm, and the outer diameter was 30 mm and the wall thickness was
I got a 2.5mm pipe. Production Example 4 Using the same extrusion apparatus as Production Example 1, a pipe was extrusion-molded using melamine-phenol resin (manufactured by Matsushita Electric Works, Ltd., trade name: ME-A) as a molding material. The temperature of each part of the cylinder is C 1 = water cooling, C 2 = 90
℃, C 3 = 120°C, C 4 = 130°C, and extrusion molding was performed at a screw rotation speed of 35 rpm to obtain a pipe with an outer diameter of 30 mm and a wall thickness of 2.5 mm. The performance of the pipes obtained at each manufacturing site was as shown in Tables 1 and 2. From these results, the thermosetting resin tube of the present invention has a good balance of strength in the tube axis direction and in the direction perpendicular to the tube axis, is strong against internal pressure, and has excellent heat resistance, flame resistance, and chemical resistance. I understand.
【表】【table】
【表】【table】
【表】【table】