JPH0573570B2 - - Google Patents
Info
- Publication number
- JPH0573570B2 JPH0573570B2 JP60151973A JP15197385A JPH0573570B2 JP H0573570 B2 JPH0573570 B2 JP H0573570B2 JP 60151973 A JP60151973 A JP 60151973A JP 15197385 A JP15197385 A JP 15197385A JP H0573570 B2 JPH0573570 B2 JP H0573570B2
- Authority
- JP
- Japan
- Prior art keywords
- injection
- temperature
- mold
- molding
- cavity
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000002347 injection Methods 0.000 claims description 34
- 239000007924 injection Substances 0.000 claims description 34
- 238000001746 injection moulding Methods 0.000 claims description 25
- 239000012778 molding material Substances 0.000 claims description 16
- 230000009477 glass transition Effects 0.000 claims description 10
- 238000000465 moulding Methods 0.000 claims description 7
- 239000004033 plastic Substances 0.000 description 14
- 229920003023 plastic Polymers 0.000 description 14
- 238000001816 cooling Methods 0.000 description 10
- 238000000034 method Methods 0.000 description 6
- 238000000748 compression moulding Methods 0.000 description 5
- 239000011347 resin Substances 0.000 description 5
- 229920005989 resin Polymers 0.000 description 5
- 238000010583 slow cooling Methods 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 3
- 229920003229 poly(methyl methacrylate) Polymers 0.000 description 3
- 239000004926 polymethyl methacrylate Substances 0.000 description 3
- 201000009310 astigmatism Diseases 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
Landscapes
- Moulds For Moulding Plastics Or The Like (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
Description
【発明の詳細な説明】
（技術分野）
本発明は、プラスチツクス製レンズ等の光学製
品を射出成形により製作する射出成形方法に関す
るものであり、高精密射出成形品の射出成形に応
用できるものである。[Detailed Description of the Invention] (Technical Field) The present invention relates to an injection molding method for manufacturing optical products such as plastic lenses by injection molding, and is applicable to injection molding of high precision injection molded products. be.
（従来の技術）
従来から、プラスチツクス製光学製品等の高精
密射出成形品の射出成形方法としては、高温射出
成形法、超高速射出成形法、超高圧射出成形法、
射出圧縮成形法等の各種の方法が提案されている
が、いずれの射出成形法も高精密な射出成形品を
製作するのにいまだに十分ではなく、とくに、プ
ラスチツクス製レンズの製作には不向きである。(Prior art) Traditionally, injection molding methods for high precision injection molded products such as plastic optical products include high temperature injection molding, ultra high speed injection molding, ultra high pressure injection molding,
Although various methods such as injection compression molding have been proposed, none of the injection molding methods is still sufficient to produce high-precision injection molded products, and is particularly unsuitable for producing plastic lenses. be.
たとえば、
高温射出成形法は、射出成形金型を成形材料
のガラス転移点温度近傍までに昇温させて、プ
ラスチツクス製レンズの成形を行うのに使用さ
れているが、高精密のプラスチツクス製レンズ
を得難い。 For example, high-temperature injection molding is used to mold plastic lenses by raising the temperature of the injection mold to near the glass transition temperature of the molding material. Lenses are difficult to obtain.
超高速射出成形法は、直径の小さなプラスチ
ツクス製レンズの製作に際しては高精密のプラ
スチツクス製レンズを得られるが、直径の大き
いプラスチツクス製レンズを製作し難い不具合
がある。 Although the ultrahigh-speed injection molding method can produce plastic lenses with high precision when producing plastic lenses with small diameters, it has the disadvantage that it is difficult to produce plastic lenses with large diameters.
超高圧射出圧縮成形法は、成形後の歪の発生
が大きいため、プラスチツクス製レンズの成形
には不向きである。 The ultra-high pressure injection compression molding method is not suitable for molding plastic lenses because it generates a large amount of distortion after molding.
これに対して射出圧縮成形法は、上記〜
の射出成形法に較べてプラスチツクス製レンズ
を高精密に成形することができる利点がある
が、複写機用レンズ、カメラの一眼レフ用レン
ズ等に使用されるプラスチツクス製レンズのよ
うに直径の大きいプラスチツクス製レンズを高
精密に射出成形できるまでには至つていない。
たとえば、複写機用レンズ等に使用されるプラ
スチツクス製レンズの直径が40mmのものでは、
その要求精度がニユートンリング評価法で干渉
縞の本数を３〜４本とされているが、この射出
圧縮成形法による場合、干渉縞の本数がせいぜ
い10本程度のものしか製作できない。また、こ
の射出圧縮成形法では、キヤビテイとランナー
との間のゲート部の形状によつてアスの発生も
ある。 On the other hand, the injection compression molding method is
Compared to injection molding methods, plastic lenses have the advantage of being able to be molded with high precision. It has not yet been possible to injection mold large plastic lenses with high precision.
For example, a plastic lens used for copying machine lenses has a diameter of 40 mm.
The required accuracy is 3 to 4 interference fringes according to the Newton ring evaluation method, but when using this injection compression molding method, it is possible to manufacture a product with only about 10 interference fringes at most. Furthermore, in this injection compression molding method, asperities may occur depending on the shape of the gate portion between the cavity and the runner.
（発明の目的）
そこで、本発明の目的は高精密な射出成形品を
成形することのできる射出成形方法を提供するこ
とにあり、とくに、直径が従来に較べて大きいプ
ラスチツクス製レンズがあつても高精密なプラス
チツクス製レンズを成形することのできる射出成
形方法を提供することにある。(Object of the Invention) Therefore, the object of the present invention is to provide an injection molding method capable of molding high-precision injection molded products. Another object of the present invention is to provide an injection molding method capable of molding highly precise plastic lenses.
（発明の構成）
本発明の射出成形方法は、成形材料のガラス転
移点温度以上の温度にあらかじめ昇温された射出
成形金型のキヤビテイに、可塑化された成形材料
をスプルーに連通するランナーとそのキヤビテイ
との間に形成されたゲートを介して注入充填した
後、このゲートをメカニカルに封止し、その後そ
の射出成形金型の温度をそのガラス転移点温度以
下に徐冷しつつ下降させて、そのキヤビテイに充
填された成形材料を硬化させて射出成形品を成形
することを特徴とするものである。(Structure of the Invention) The injection molding method of the present invention includes a runner that communicates the plasticized molding material to the sprue, which is placed in the cavity of an injection mold whose temperature has been raised in advance to a temperature equal to or higher than the glass transition temperature of the molding material. After injecting and filling through the gate formed between the mold and the cavity, this gate is mechanically sealed, and then the temperature of the injection mold is gradually lowered to below its glass transition temperature. The molding material filled in the cavity is cured to form an injection molded product.
以下に、本発明に係る射出成形方法の実施例を
図面を参照しつつ説明する。 Embodiments of the injection molding method according to the present invention will be described below with reference to the drawings.
第１図において、１は射出成形金型としての固
定側金型を示し、この固定側金型１に対向する射
出成形金型としての可動側金型は図示が省略され
ている。固定側金型１は回転体２と本体３とから
構成され、回転体２にはスプルー４とランナー５
とが形成され、本体３にはキヤビテイ６が形成さ
れている。ここでは、このキヤビテイ６はプラス
チツクス製レンズ成形用とされ、キヤビテイ６は
略半球形面形状とされ、その直径は略40mmであ
る。本体３は回転体２とキヤビテイ６との間がゲ
ート部７とされ、成形材料はスプルー４、ランナ
ー５、ゲート部７を通つてキヤビテイ６に注入充
填されるものであり、ここでは、成形材料にはポ
リメチルメタクリレートが使用されている。この
ポリメチルメタクリレートは図示を略す射出成形
機から射出されるもので、その樹脂温度は200〜
260℃とされ、ポリメチルメタクリレートは可塑
化されて溶融状態となつている。 In FIG. 1, reference numeral 1 indicates a fixed side mold as an injection mold, and illustration of a movable side mold as an injection mold opposite to the fixed side mold 1 is omitted. The stationary mold 1 is composed of a rotating body 2 and a main body 3, and the rotating body 2 has a sprue 4 and a runner 5.
A cavity 6 is formed in the main body 3. Here, this cavity 6 is used for molding a plastic lens, and the cavity 6 has a substantially hemispherical surface shape, and its diameter is approximately 40 mm. The main body 3 has a gate section 7 between the rotating body 2 and the cavity 6, and the molding material is injected into the cavity 6 through the sprue 4, the runner 5, and the gate section 7. Here, the molding material polymethyl methacrylate is used. This polymethyl methacrylate is injected from an injection molding machine (not shown), and the resin temperature is 200~
At 260°C, polymethyl methacrylate is plasticized and in a molten state.
射出成形金型としての固定側金型１と可動側金
型（図示を略す）とは、成形材料の射出充填前に
あらかじめ成形材料のガラス転移点温度以上の温
度に温度調節されているものであり、ここでは、
固定側金型１と可動側金型とは射出時の温度が
130℃に設定されている。射出後は充填状態を考
慮して0.1〜20secの保圧をかけながら回転体２を
第１図に示すランナー５とキヤビテイ６との連通
状態から第２図に示す非連通状態になるように矢
印方向に回転させてメカニカルにゲート部７を封
止し、キヤビテイ６の内圧が失われないようにす
る。この実施例のものでは、そのキヤビテイ６の
内圧は400〜1200Kg／cm2である。その後、射出成
形金型の型温度を徐々に下降させてガラス転移点
温度以下まで徐冷する。この実施例では、成形材
料のガラス転移点温度が104〜105℃と想定される
ので104〜90℃まで射出成形金型としての固定側
金型１と可動側金型（図示を略す）とを徐冷す
る。 The fixed side mold 1 and the movable side mold (not shown), which serve as injection molding molds, are temperature-controlled in advance to a temperature higher than the glass transition temperature of the molding material before injection and filling of the molding material. Yes, here:
Fixed side mold 1 and movable side mold have temperatures at the time of injection.
The temperature is set at 130℃. After injection, while applying a holding pressure of 0.1 to 20 seconds in consideration of the filling state, move the rotor 2 from the state of communication between the runner 5 and the cavity 6 shown in FIG. 1 to the state of non-communication shown in FIG. 2 using the arrows. The gate portion 7 is mechanically sealed by rotating in the direction to prevent the internal pressure of the cavity 6 from being lost. In this embodiment, the internal pressure of the cavity 6 is 400 to 1200 kg/cm 2 . Thereafter, the mold temperature of the injection mold is gradually lowered to slowly cool the mold to below the glass transition temperature. In this example, since the glass transition point temperature of the molding material is assumed to be 104 to 105°C, the fixed mold 1 and the movable mold (not shown) as injection molding molds are used up to 104 to 90°C. Cool slowly.
この射出成形金型の徐冷は第３図に符号Ａで示
すように直線的に行うものであつてもよいし、ま
た、第３図に符号Ｂで示すように自然に徐冷する
ものであつてもよいが、自然放置による徐冷は環
境条件によつて冷却速度が大きく変化することが
あるから、なるべく自然放置によらずコントロー
ルしつつ徐冷することが望ましい。なお、自然放
置による場合、射出成形金型への成形材料の充填
によつて温度調節された射出成形金型の型温度が
第３図に符号Ｃで示すように若干上昇する。 This slow cooling of the injection mold may be carried out linearly as shown by the symbol A in FIG. 3, or it may be carried out naturally as shown by the symbol B in FIG. However, since the cooling rate may vary greatly depending on the environmental conditions in slow cooling by leaving to stand naturally, it is desirable to perform slow cooling under control, rather than by leaving to stand naturally. Incidentally, when the mold is left to naturally stand, the mold temperature of the injection mold, whose temperature has been adjusted by filling the injection mold with the molding material, rises slightly as shown by symbol C in FIG.
この徐冷は、極めて冷却速度を遅くするのが好
ましく、実験的に冷却速度を１℃／min、２℃／
min、６℃／minに設定して行つてみたが、１
℃／minの冷却速度で射出成形金型を徐冷して得
た射出成形品の品質は他の冷却速度で射出成形金
型を徐冷して得た射出成形品の品質よりも良好で
あつた。しかし、射出成形品の肉厚によつて最適
な冷却速度が存在するものと考えている。要する
に、金型に接している溶融樹脂部分の樹脂温度と
中央部分の樹脂温度とに温度差が極力生じないよ
うにして冷却させることである。 It is preferable to slow down the cooling rate of this slow cooling, and experimentally the cooling rate was set to 1°C/min, 2°C/min.
I tried setting it to min, 6℃/min, but 1
The quality of the injection molded product obtained by slowly cooling the injection mold at a cooling rate of ℃/min is better than the quality of the injection molded product obtained by slowly cooling the injection mold at other cooling rates. Ta. However, we believe that there is an optimal cooling rate depending on the wall thickness of the injection molded product. In short, the purpose is to cool the molten resin in a manner that minimizes the temperature difference between the resin temperature of the molten resin portion in contact with the mold and the resin temperature of the central portion.
（発明の効果）
本発明に係る射出成形方法は、以上説明したよ
うに、成形材料のガラス転移点温度以上の温度に
あらかじめ昇温された射出成形金型のキヤビテイ
に、可塑化された成形材料をスプルーに連通する
ランナーとそのキヤビテイとの間に形成されたゲ
ートを介して注入充填した後、このゲートをメカ
ニカルに封止し、その後その射出成形金型の温度
をそのガラス転移点温度以下に徐冷しつつ下降さ
せて、そのキヤビテイに充填された成形材料を硬
化させて射出成形品を成形することを特徴とする
ものであるから、高精密な成形品を成形でき、特
に、レンズの製作にあつては成形精度がニユート
ンリング法で評価して１〜２本のプラスチツクス
製レンズを成形することができる。(Effects of the Invention) As explained above, in the injection molding method according to the present invention, a plasticized molding material is placed in the cavity of an injection molding die whose temperature has been raised in advance to a temperature equal to or higher than the glass transition temperature of the molding material. is injected and filled through a gate formed between the runner communicating with the sprue and its cavity, this gate is mechanically sealed, and the temperature of the injection mold is then lowered to below its glass transition temperature. Since it is characterized by slowly cooling and lowering the molding material filled in the cavity to harden the injection molded product, it is possible to mold highly precise molded products, and is particularly suitable for manufacturing lenses. In this case, the molding accuracy can be evaluated by the Newton ring method, and one or two plastic lenses can be molded.
また、従来の射出成形法によるとアスが発生し
やすいが、本発明に係る射出成形方法によればこ
のアスの発生を抑制できる効果を奏する。 In addition, although the conventional injection molding method tends to generate astigmatism, the injection molding method according to the present invention has the effect of suppressing the occurrence of astigmatism.
第１図は本発明に係る射出成形方法に使用する
射出成形金型の固定側金型を示す平面図、第２図
は第１図に示すゲートをメカニカルに封止した状
態を示す固定側金型の平面図、第３図は射出成形
金型の徐冷の一例を示す冷却特性図である。
１……固定側金型、２……回転体、３……本
体、４……スプルー、５……ランナー、６……キ
ヤビテイ、７……ゲート部。
FIG. 1 is a plan view showing the stationary side mold of an injection mold used in the injection molding method according to the present invention, and FIG. 2 is a plan view showing the stationary side mold in which the gate shown in FIG. 1 is mechanically sealed. FIG. 3, which is a plan view of the mold, is a cooling characteristic diagram showing an example of slow cooling of an injection mold. 1... Fixed side mold, 2... Rotating body, 3... Main body, 4... Sprue, 5... Runner, 6... Cavity, 7... Gate section.
Claims (1)
らかじめ昇温された射出成形金型のキヤビテイ
に、可塑化された成形材料をスプルーに連通する
ランナーと前記キヤビテイとの間に形成されたゲ
ートを介して注入充填した後、該ゲートをメカニ
カルに封止し、その後前記射出成形金型の温度を
前記ガラス転移点温度以下に徐冷しつつ下降させ
て、前記キヤビテイに充填された成形材料を硬化
させて射出成形品を成形することを特徴とする射
出成形方法。1. The plasticized molding material is introduced into the cavity of an injection molding die whose temperature has been raised in advance to a temperature equal to or higher than the glass transition temperature of the molding material through a gate formed between the cavity and a runner that communicates with the sprue. After injecting and filling, the gate is mechanically sealed, and then the temperature of the injection mold is gradually lowered to below the glass transition point temperature to harden the molding material filled in the cavity. An injection molding method characterized by molding an injection molded product.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15197385A JPS6211619A (en) | 1985-07-09 | 1985-07-09 | Process of injection molding |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15197385A JPS6211619A (en) | 1985-07-09 | 1985-07-09 | Process of injection molding |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25806394A Division JPH07251434A (en) | 1994-10-24 | 1994-10-24 | Injection molding method for optical product |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6211619A JPS6211619A (en) | 1987-01-20 |
| JPH0573570B2 true JPH0573570B2 (en) | 1993-10-14 |
Family
ID=15530268
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15197385A Granted JPS6211619A (en) | 1985-07-09 | 1985-07-09 | Process of injection molding |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6211619A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2537231B2 (en) * | 1987-05-07 | 1996-09-25 | キヤノン株式会社 | Plastic lens molding method |
| JP3385491B2 (en) * | 1994-06-21 | 2003-03-10 | コニカ株式会社 | Injection molding method |
| JP4972760B2 (en) * | 2004-06-29 | 2012-07-11 | コニカミノルタアドバンストレイヤー株式会社 | Optical element manufacturing method |
| JP4815898B2 (en) * | 2004-06-29 | 2011-11-16 | コニカミノルタオプト株式会社 | Injection mold and injection molding method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5196854A (en) * | 1975-02-20 | 1976-08-25 | PURASUCHITSUKURENZUNO SEIZOHO | |
| JPS5812738A (en) * | 1981-07-16 | 1983-01-24 | Matsushita Electric Ind Co Ltd | Heat cycle injection compression molding method |
| JPS5924620A (en) * | 1982-08-03 | 1984-02-08 | Konishiroku Photo Ind Co Ltd | Formation of thick resin molding |
| JPS61233520A (en) * | 1985-04-09 | 1986-10-17 | Canon Inc | Preparation of molded product |
| JPS61258719A (en) * | 1985-05-14 | 1986-11-17 | Olympus Optical Co Ltd | Mold for injection molding |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5795911U (en) * | 1980-12-02 | 1982-06-12 | ||
| JPS59169919U (en) * | 1983-04-27 | 1984-11-14 | 矢崎化工株式会社 | Multi-cavity mold |
-
1985
- 1985-07-09 JP JP15197385A patent/JPS6211619A/en active Granted
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5196854A (en) * | 1975-02-20 | 1976-08-25 | PURASUCHITSUKURENZUNO SEIZOHO | |
| JPS5812738A (en) * | 1981-07-16 | 1983-01-24 | Matsushita Electric Ind Co Ltd | Heat cycle injection compression molding method |
| JPS5924620A (en) * | 1982-08-03 | 1984-02-08 | Konishiroku Photo Ind Co Ltd | Formation of thick resin molding |
| JPS61233520A (en) * | 1985-04-09 | 1986-10-17 | Canon Inc | Preparation of molded product |
| JPS61258719A (en) * | 1985-05-14 | 1986-11-17 | Olympus Optical Co Ltd | Mold for injection molding |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6211619A (en) | 1987-01-20 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |