JPS6178613A - Manufacture of polymer molded item - Google Patents

Abstract

PURPOSE:To make it possible to remove a polymer item from a mold without damaging the polymer item, by cooling and solidifying the polymer item confined in the mold while treating the polymer item with ultrasonic waves. CONSTITUTION:A mixture solution that contains a monomer that is a raw material for a polymer, a polymerization initiator and a polymerization regulator is confined in a vessel for producing a polymer item, and is heated under pressure to produce a polymer item. While the produced polymer item is irradiated with ultrasonic waves, the polymer item in the vessel is cooled and hardened, then the polymer item is removed. When the ultrasonic wave treatment is carried out, the vessel in which the polymer item is confined may be placed in a medium and irradiated with ultrasonic waves. The medium used is preferably water. The temperature at which the cooling and hardening is carried out under the irradiation of ultrasonic waves is preferably the transition temperature of the polymer or a temperature a little below the transition temperature of the polymer. The transition temperature refers generally to the glass transition temperature. Since while the polymer item is treated with ultrasonic waves, the polymer item is cooled from the melted state to or below the mold temperature and the glass transition temperature to be solidified, the removal of the polymer item is facilitated with avoiding the damage thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a polymer bottom shape having excellent mold shape stability and production stability.

[Conventional technology]

IM in a heated or heated pressurized atmosphere inside the bottom mold.
At present, the remaining polymer is removed from the polymer manufacturing container by cooling the polymer contents including the bottom mold or the polymer manufacturing container.

This is because the thermal shrinkage rate of the polymer content generally shows a non-negligible difference from that of the mold or container used for producing polymers, and as a result of step 7, the content of the polymer can be easily reduced by simply going through a cooling process. The reason is that since the objects can be separated, there is no major problem in taking them out.

This is because bottom molds and containers for producing polymers are made of metal or hard glass, and the thermal shrinkage rate of polymers is much greater than that of those containers. However, in the above method, the shape of the mold may not be restored due to the content of the polymer. For example, if there is a peeling scratch on the peeling surface, heat shrinkage distortion will occur if the inner surface of the mold or polymer manufacturing container has low smoothness.
In particular, if the mechanical strength is insufficient, stress will concentrate on the weakest part when the polymer content is cooled, often resulting in damage to the content. Therefore, although the content polymer maintains a satisfactory shape in the molding mold or in the polymer production container under heating or heating and pressure, it may break during the removal process and the production stability may deteriorate. The current situation is that this is having a major negative impact on the depth of the product.

[Problems that the invention attempts to solve]

An object of the present invention is to produce a polymer with excellent production stability by ejecting the polymer while maintaining the shape of the polymer enclosed in a mold.

[A precautionary measure to resolve the problem]

After cooling and solidifying the polymer content while irradiating ultrasonic waves to the mold container containing the polymer sealed in a heated state according to the present invention,
A method for producing a polymer content, characterized by taking out a polymer shaped into a mold shape.

When enclosing a polymer in a mold in a heated or heated pressurized atmosphere, the molten polymer is pressed into the mold using oil pressure, air pressure, screw rotor pressure, etc. using ultrasonic waves. The present invention includes cooling and solidifying the polymer content while irradiating it and removing it.

In addition, after sealing a mixed solution containing monomers, which are the raw materials for the polymer, a polymerization initiator, and a polymerization degree regulator in a polymer production container, the produced polymer is heated or heated and pressurized and then subjected to ultrasonic waves. It is included in the present invention that the polymer content is cooled and solidified while being irradiated.

In the case of ultrasonic irradiation, the ultrasonic wave in the present invention means an elastic wave whose frequency exceeds the vibration frequency range or the audible frequency range. As the generated sound waves, piezoelectric vibrators such as crystal, electrostrictive vibrators such as barium titanate, etc. are used at relatively high frequencies. 100
Magnetostrictive vibrators (nickel, ferrite) are often used below M'fl*.

The ultrasonic waves used in the present invention preferably range from I KHz to I GHz, particularly preferably from 5 KFiz to I MHz. From a practical standpoint, an electrostrictive vibrator or a magnetostrictive vibrator is preferable as the camera element.

The intensity of the ultrasonic waves to be irradiated is from IW/cyt" to 1xv,'
A range of 2 is preferable, especially 10W/mouth 2 to 200
A range of W/tan 2 is preferable. If it is more than I KW/cm", the polymer itself may be destroyed. If it is less than I W/3", there is sufficient releasability between the container and the polymer contents. This is because it is not recognized.

Comparatively I8 with metal containers and glass containers! Polymethyl methacrylate resins, acrylonitrile-butadiene-styrene resins, polyacetal resins, polycarbonate resins, polyester resins, and polyarylate resins have good iK strength in the cooling and solidification process from the molten state. In such a case, good shape stabilization can be obtained even if the ultrasonic output is relatively large within the above range.

- In the case of non-polar polymers such as polyethylene, polypropylene/polystyrene, etc., which have relatively low adhesion strength to metal containers and glass containers, good results can be obtained even if the ultrasonic output is low within the above range. .

Among thermosetting resins such as epoxy resins, phenolic resins, urea and melamine resins, and thermosetting 711 resins, epoxy resins and phenolic resins are preferably treated with relatively high frequency and high power ultrasonic waves.

During ultrasonication, the mold container t containing the encapsulated polymer
- Ultrasonic irradiation may be performed in the medium.

The medium to be used is preferably an aqueous medium, but an alkaline aqueous solution or an acidic aqueous solution can also be used. When cooling and solidifying while irradiating ultrasonic waves, the temperature is preferably the transposition temperature of the polymer or a temperature slightly lower than the transposition temperature.

This is because the specific volume of the polymer changes significantly near the transposition temperature of the polymer.

The transition temperature is usually expressed as the glass transition temperature.

Below the glass transition temperature, the coefficient of thermal expansion is smaller than that of a polymer above the glass transition temperature. Therefore, when the polymer is heated in the mold container, it is in a molten state! ! Heat shrinkage occurs by cooling and solidifying below the glass transition temperature, and as a result of step 7, it becomes possible to take out the polymer shaped into the mold shape.

However, if the peeled surface lacks smoothness (such as when the surface has complex peeling scratches), the polymer content will be damaged.While being treated with ultrasonic waves, the molten state is cooled to below the mold temperature and glass transition temperature. Solidification facilitates the removal and prevents damage to the polymer content.

Practically speaking, it is preferable that the ultrasonic irradiation temperature be at a temperature that causes a change in the morphology of the polymer content, such as near the glass transition temperature. ! Even if a substance does not have l, it is possible to obtain a sufficient ultrasonic treatment effect by cooling it from a molten state (as long as the elasticity of the resin content becomes high).

Therefore, by cooling and solidifying after ultrasonic treatment, it becomes possible to eject the mold-shaped polymer without damaging the polymer.

〔Example〕

The present invention will be explained in more detail with reference to Examples below.

The ultrasonic treatment device is a lead zirconate titanate ultrasonic vibrator,
A barium titanate ultrasonic transducer and a ferrite ultrasonic transducer were used.

Example 1 Polymethyl methacrylate (Mitsubishi Rayo/Acrypet VH) pellets were dried at 90°C using a hot air dryer.
After drying for a period of time, the flat transparent plate was processed into a bottom shape using a 30φ screw type injection molding machine (1 oz. Bk'1-50 type manufactured by Yamaguchi Seiki Seisakusho). The mold temperature was 85°C, the cylinder temperature was 250°C, and the injection pressure was 1400 Yu/side 2.

The temperature of the mold was controlled by using an in-mold hot water pipe circulation method, and a lead titanate zirconate ultrasonic vibrator was installed on the lower side of the mold, with an oscillation frequency of 45 KHz and an ultrasonic output of 100 W.

The molten polymer is injected into the mold at an injection pressure of 1400' and 9/cm'', and at the same time, 85°C hot water is passed through the mold to cool it, and while cooling and solidifying the molten polymer in mold P3, it is irradiated with ultrasonic waves for 50 minutes. An injection molded product with good shape stability was obtained. When 100 pieces were produced under the same conditions, all 100 pieces were standard flat transparent plates (80X100X2+
w) was obtained.

Example 2 A polymethyl methacrylate pellet was molded in the same manner as in Example 1. Ultrasonic irradiation was performed for t-5 minutes at a mold temperature of 30° C., and a bottom-shaped product was obtained in the same manner. When 100 sheets were made, all 100 sheets were standard flat transparent plates (80X100X
2*w) was obtained.

Examples 3 to 11 Injection molding was carried out in the same manner as in Example 1 using the polymers shown in Table 1. The results are shown in Table-1.

Example 12 After drying a heavy weight of methyl methacrylate on a molecular sieve (4A1716 chip) and distilling it under atmospheric pressure under an argon gas atmosphere, 1 mol of 2-azobisisobutyronitrile LL0 and Cert-dodeflumerca were added. After dissolving 15 mol% of methyl methacrylate monomer VC, one side of the piston was pressurized and moved into a cylindrical type/linda cell (
The above monomer mixture was charged into a stainless steel (inner surface mirror finished), a pressure of 20 to 9 per unit area was applied to the movable piston, and the oil jacket temperature was 60°C for 7Jn.
It was thermally polymerized.

After the polymerization reaction conversion rate due to polymerization shrinkage reached 100%, the piston pressurized Linder cell was removed from the jacket with the piston attached, and the missing frequency was 45 using a zirco titanate/lead acid ultrasonic vibrator in 70°C warm water. KHz
, irradiated with ultrasonic power of 250 W for 20 minutes ◇ Pressurized moving piston / upper and lower parts were removed from the printer cell 7
A cylindrical mold polymer with a height of 30 mm and a diameter of 2.9 mm was produced in IJ Darcel.

It was a mold polymer that had completely restored the shape inside the cylindrical 7 Linder cell mold, and was a perfect mold polymer with no air bubbles in the cracked 9 polymer. As a result of manufacturing 100 bottles, a standard transparent polymer was obtained for all 100 pieces.

Example 15 After drying the styrene monomer on a molecular sieve (5A1/16), it was distilled under atmospheric pressure in an argon gas atmosphere, and then Z2/-azobisisobutyronitrile (10
After dissolving 2 mol% and 1 mol% of tert-dodecyl mercaptan [L] in styrene monomer, it was prepared in the same manner as in Example 12 in a cylindrical cylinder cell (made of stainless steel with a circular mirror finish) with an oil jacket and a separate pressure moving piston. The above monomer mixture was charged and polymerized by heating at an oil jacket temperature of 70°C by applying a pressure of 920 hours per unit area to a movable piston.

After the polymerization reaction conversion rate due to polymerization shrinkage reached 100%, the piston pressurized moving cylinder cell was released from the jacket, and the oscillation frequency was 45 KHz and the ultrasonic output was 250 using a lead titanate zirconate ultrasonic vibrator in 70°C hot water.
It was irradiated with W for 20 minutes.

The moving piston was removed from the cylinder cell, resulting in a cylindrical mold polymer with a height of 30 cm and a diameter of 2.95 cm, which was green-bottomed within the cylinder cell.

It was a mold polymer that displayed the shape inside the cylindrical cylinder cell mold as it was, and was a perfect mold polymer that did not wrinkle or have air bubbles enter the center of the cell. As a result of manufacturing 100 bottles, a standard transparent polymer was obtained for all 100 pieces.

Implementation@14 A cylindrical template copolymer was obtained in the same manner as in Example 12 using the mixture of methacrylate styrene monomers (weight ratio 1/1) used in Example 12.13 as a raw material.

Example 15 After drying the acrylonitrile monomer on a molecular sieve (4A 1716 chip) and distilling it under normal pressure in an argon gas atmosphere, it was mixed with the styrene monomer used in Example 13 (weight ratio 3 nia). A cylindrical template copolymer was obtained in the same manner as in Example 13 using the following materials.

Example 16 Methyl acrylate monomer was dried on a molecular sieve (4 ml 1/i 6 chips) and then distilled under normal pressure under an argon gas atmosphere, and methyl methacrylate used in Example 12. A cylindrical template copolymer was obtained as a monomer mixture (weight ratio near S) by the method of Example 12 and Iroku.

Example 17 Ethylene glycol dimethacrylate dried on molecular sieves (4 ml 1/16 chips) was distilled under atmospheric pressure under a total argon gas atmosphere, and then a mixture with the methyl methacrylate monomer used in Example 12 (weight ratio 1:9
) was used as a raw material, and the entire cylindrical template crosslinked copolymer was obtained in the same manner as in Example 12.

Example 18 Divinylpe/zene dried on a molecular sieve (4A 1/16 chip) was distilled under normal pressure under an argon atmosphere, and then mixed with the styrene monomer used in Example 15 (weight ratio 1:9). A cylindrical template crosslinked copolymer was obtained in the same manner as in Example 15 using as a raw material.

Example 19 After obtaining a methyl methacrylate monomer in the same manner as in Example 12, the methyl methacrylate monomer was charged into a stirring vessel with a cooling w, and after heating and stirring in a 70°C hot water bath, O, OO5 After t-initiating the polymerization of 2,2'-azobisisobutyronitrile, the methyl methacrylate monomer rapidly polymerized due to the exothermic polymerization.

After boiling and reaching a peak temperature, the mixture was cooled to obtain a 55% methyl methacrylate silub. After passing the obtained sillage through a 50 μm filter, 1c
Into the above methyl methacrylate/Lag solution was added: 2,2'-azobisiso Butyronitrile [1005
After melting and charging mol%, two glass plates were fixed and cell cast polymerization was carried out in 70T warm water. After the polymerization conversion rate reached 90% or more, it was heated at 120°C for 2 hours, then placed in hot water at 70°C and heated with a lead titanate zirconate ultrasonic vibrator at an oscillation frequency of 45 KHz and an ultrasonic output of 250 W for 20 minutes. Irradiated.

A transparent resin plate with a thickness of 7.5 m was obtained, and 100 plates were manufactured, and all 100 plates were made of standard transparent polymer.

Comparative Example 1 When monomers were charged and polymerized in the same manner as in Example 12 and the polymer was taken out without ultrasonic treatment, cracks occurred at the lower part of the cylindrical mold polymer. When 10 pieces were manufactured, cracks occurred in the cylindrical mold polymer in all 10 pieces.

Comparative Example 2 ''Jr: When monomers were charged and polymerized using the same method as in Example 15 and the polymer was extruded without ultrasonic treatment, cracks occurred at the bottom of the cylindrical mold polymer. .1
When 0 pieces were not manufactured, cracks occurred in the cylindrical mold polymer for all 10 pieces.

〔Effect of the invention〕

According to the method of the present invention, while maintaining the shape of the polymer,
The shaped polymer can be easily removed from the mold without being damaged, and the shaped polymer can be manufactured at low production costs.

Claims (1)

[Claims] Manufacture of a polymer molded product characterized by cooling and solidifying the polymer content while irradiating ultrasonic waves to a mold container containing a polymer sealed in a heated state, and then taking out the polymer molded into a mold shape. Method.