JPS59124815A - Novel molding method - Google Patents

Abstract

PURPOSE:To facilitate the molding of a biaxially oriented molding, e.g., thick sheets, pipes, etc., in highly viscous state by molding a thermoplastic resin while covering the resin with a polymer having a specific viscosity. CONSTITUTION:When a compressive force is applied to a compression molding die 11 to press a thick elemental material 12 composed of a thermoplastic resin 13 and a covering polymer 14 whose viscosity is 1,000cps or more, 1/10 or less of the viscosity of the thermoplastic resin during the molding period, containing 1-20wt% an additive having excellent lubricity preferably, the thick elemental material 12 is biaxially oriented. Under the condition, the compression molding die 11 is cooled, a molding 13 is hardened and taken out of the die 11, the polymer of the surface layer of the molding 13 is peeled off to obtain a biaxially oriented molding. By the compression molding method, a biaxially oriented sheet having a 1-10mm. thickness and a 1.5-7 times draw ratio can be molded with good efficiency.

Description

[Detailed description of the invention] This relates to improvements in rolling forming.

The purpose of the present invention is to improve the moldability of resins that are difficult to extrude due to their high viscosity, such as ultra-high molecular weight resins, and to improve molding that requires extrusion in a high viscosity state, such as foam extrusion molding. , improvements in extrusion molding of easily thermally decomposable resins such as polyvinylidene chloride, improvements in the method of biaxially stretching in an extrusion die in a high viscosity state to form biaxially oriented zotes or eaves, and compression molds. This is a new molding method that achieves improvements such as improving the method of compressing thermoplastic resin to form a biaxially oriented sheet, and improving the method of inserting thermoplastic resin between heated rolls and rolling it to form it. be.

In extrusion molding, compression molding, or roll rolling of thermoplastic resins, it is already known to coat the inner surface of the die or the surface of the rolls with a lubricant in order to improve resin flow within the die or between the rolls. For example USP 259
7553, USP 26881.53.

It is described in USP3504075 etc. By coating the inner surface of the die with a lubricant, the flow of the thermoplastic resin within the die is significantly improved, allowing molding to be performed at low pressure. However, there are various problems with lubricant coating on the inner surface of the die.

The biggest problem is that it is difficult for the lubricant to uniformly wet the inner surface of the die, and the resin flows faster in areas coated with a large amount of lubricant, making it difficult to mold uniformly. It is stated in US Pat. No. 4,087,222 that if the inner surface of the die is made rough, it is difficult to uniformly coat the inner surface of the die with lubricant, but this is not sufficient. Furthermore, the lubricant tends to leak from the die, so it is necessary to assemble one die with precision-machined die parts. Furthermore, it is necessary to clean the lubricant from the molded article, and there are problems such as there being no easy cleaning method.

The present invention is a molding method that improves these problems and is characterized by using a polymer having a viscosity of 1000 poise or more during molding instead of the hitherto known lubricant.

That is, 1. The present invention is applicable to extrusion molding, compression molding, or rolling molding in which a heated thermoplastic resin is compressed in a goo, extruded in a goo, or rolled with rolls. This is a novel molding method characterized in that the thermoplastic resin is molded while being coated with a polymer having a viscosity of I/10 or less and 1000 voids or more of the thermoplastic resin at the time of molding.

Preferably, the viscosity of the polymer during molding is 1150 or less and 5000 voids or more, which is the viscosity of the thermoplastic resin.

Further, it is preferable to incorporate additives with excellent lubricity into the polymer.

The lower the viscosity of the polymer of the present invention, the thinner the coating can be, but the more difficult it is to achieve uniform coating. The polymer viscosity at the time of molding is 1000 voids, and 100
When the poise falls below 0 poise, defects that have been a problem with conventional lubricants occur. More preferably, it is 5000 voices or more. On the other hand, as the viscosity of the polymer increases,
In order to improve the flow of resin within the die, it is necessary to increase the thickness of the powder coating. The reason why the coating effect is economically recognized is that the viscosity of the polymer during molding is 1/1 of the viscosity of the thermoplastic resin.
10 or less, preferably GJ: 1150 or less.

In the present invention, the thermoplastic resin may be a multilayer body of two or more types, in which case the viscosity of the thermoplastic resin described in the present invention is the lowest viscosity. That is, of the two or more resins, a polymer having a viscosity of 1/10 or less of the lowest resin viscosity and 1000 poise or more is used for the coating material.

Furthermore, in the present invention, it is particularly effective to coat the inner surface of one die with a solid having excellent sliding properties of polytetrafluoroethylene groups. As solids with poor sliding properties, various fluorinated hydrocarbon polymers that do not soften at molding temperatures, such as polytetrafluoroethylene, can be used favorably. Industrial materials, ■, /M6. Coating the inner surface of the goo with Teflock processing as described in '97 et al. has good wear resistance during molding and can be particularly well used in the present invention.

The present invention will be explained with reference to the drawings.

FIG. 1 is an explanatory diagram showing the flow state of resin and polymer in the die.

FIG. 2 is a graph showing the relationship between temperature and viscosity of various thermoplastic resins or polymers.

FIG. 3 is an explanatory view showing the process of molding a biaxially oriented sheet by compression molding.

Figures 4 and 7 are cross-sectional drawings showing an apparatus for forming biaxially oriented sheets using the extrusion method. Figure 5 is an enlarged view of the stretched portion for forming biaxially oriented sheets using the apparatus shown in Figure 4. FIG.

FIG. 6 is a cross-sectional drawing showing an apparatus for forming biaxially oriented pipes by extrusion molding.

FIG. 8 is a graph showing the relationship between resin viscosity and temperature.

FIG. 9 is a sectional view showing an apparatus for molding a foam by the paper pressing method.

In FIG. 1, heat-plasticized thermoplastic resin or
It shows the velocity at each position when thermoplastic resin and polymer flow inside the goo. When the thermoplastic resin is flowed through the die at a low speed, a speed 1 and a speed curve 2 shown in (1-1) are shown. When flowing at high speed, a velocity curve 3 shown in (1-2) is shown. (
]-1) and (]-2), shearing force acts in the resin,
As a result, flow resistance becomes significantly large when high viscosity resin flows inside the goo. In addition, the flow of the resin shown in (1-1) and (1-2) in the gui is not suitable for biaxial stretching in a die.

When the inner surface of the gou is uniformly and sufficiently coated with lubricant, the resin slides on the gou surface, creating a so-called plug flow state (1-3). However, it is difficult to coat the lubricant uniformly on the inner surface of the goo, and if it becomes uneven, it may flow (] -1
, ) or (1-2) and (1-3), resulting in a large turbulence.

Instead of lubricant, use at least 1/10 of the resin viscosity during molding],
When the polymer 4 having a void size of 000 or more is made to flow together with the thermoplastic resin 5 while covering the inner surface of the goo, a velocity curve 6 shown in (1-4) is obtained. ] If the melt becomes more than 000 poise, it will be difficult to extrude it with a gear pump of an ordinary thermoplastic resin extruder, so when extrusion molding is performed using the method of the present invention, the result will be similar to three-layer extrusion molding. . ] With a polymer having a poise of 000 poise or more, it becomes easy to uniformly coat the Gui white coat m1, and the plug flow of the resin 50 portion can be stably maintained.

As the viscosity of the polymer increases, it is necessary to increase the thickness 7 of the polymer layer, and a thickness of 1/10 or less of the resin viscosity can be used economically. When the polymer viscosity approaches the resin viscosity, (]−
The flow curve 8 as shown in 5) is obtained, and it is necessary to flow a large amount of polymer in order to cause the resin layer to plug flow, and it is necessary to simultaneously push a larger amount of polymer that allows smooth molding than the resin that you want to mold. It will be necessary to take it out.

In the present invention, the viscosity of the coating polymer is appropriately selected, and a small amount of the polymer can be coextruded to achieve good molding. Particularly preferred is the flow curve 6 shown in (1, -6), and it is preferred that the polymer layer has the fastest flow section 9. More preferably, as shown in (]-7), the inner surface of the goo is provided with a coating layer 10 coated with a solid having poor sliding properties, such as polytetrafluoroethylene, and the coating layer 10 is coated with a polymer 40 surface layer and a thermoplastic material. When the three layers consisting of the inner core layer 5 of resin are made to flow, the FM 31. The interface between the o and the 40 polymer layers provides good slippage, allowing for stable and good molding.

Furthermore, when an additive with excellent lubricity is added to the polymer, slippage occurs between the polymer and the inner surface of the goo, resulting in a flow similar to that shown in (1-7), and favorable results can be obtained.

To obtain only a plug-flowed resin layer, the polymer layer is peeled off from the molded product after molding. In this case, the resin and polymer are preferably non-adhesive to the extent that they can be easily peeled off, and if only the resin layer is used, it is more economical to make the assembly layer thinner. The thickness of one surface of the polymer layer is preferably 1/10 or less of the thickness of the resin layer; 1. The viscosity of the polymer is preferably such that the resin/resin layer can be made into a plug flow with a thickness of /1.0 or less.

Figure 2 shows the relationship between temperature and viscosity of various resins.

In Figure 2, PMMA, (]'# 4,4.00,
000) is polymethyl methacrylate 1, J with a weight average molecular weight of 4/10000, molded by Celgiast polymerization.
) MMA (MW ], 5o, o o o) is a methyl methacrylate copolymer with a weight average molecular bond of 150,000 methyl acrylate and 3%, A] 3S #301 is ABS resin, Stylac #30J ( Asahi Kasei Industries, Ltd.
), Ps #666 is polystyrene resin, Styron #
666 (manufactured by Asahi Kasei Industries, Ltd.) (MI O, 5)
and PP (MI4) are polypropylenes with me/l'l-'1 indexes of 0.5 and 4, and PEM6520 is low-density polyethylene M6'520 (manufactured by Asahi Kasei Industries, Ltd.). In the molding of PMMA, PS, A]3S, PP and PR can be favorably used as polymers to coat the inner surface of the die. Soft resins such as PP and PE are PMMA, P
It can be successfully used as a coating polymer for the inner surface of the molding die.

Polyolefins such as PP and PE have the property of easily slipping inside the die and are good as coating polymers.

In order to make the inside of the goo more slippery, it is preferable to add an additive having excellent lubricity to the polymer. As additives with excellent lubricity, fatty acid salts such as fatty acid calcium stearate such as stearic acid, silicone oils such as various fatty acid ester polydimethylzologisane, or low molecular compounds that bleed more easily than polymers are used. The more these additives with excellent lubricity V1- are added, the better the slippage will be, but if too much is added, the polymer will become brittle, which is not preferable. Generally, it is preferable to add 1 to 20% by weight. In the present invention, the fact that the viscosity during molding is 1/1o or less and 1000 voids or more indicates the viscosity after adding additives.

Next, a case in which 2M orientation molding of a thermoplastic resin is performed using the method of the present invention will be described.

FIG. 3 shows the process of forming a biaxially oriented sheet by compression molding. A thick-walled base material 12 heated to a temperature above the glass transition temperature and below the melting point of the thermoplastic resin is placed in a compression molding die 11 heated appropriately (3-1).

The thick-walled base material 12 is composed of a thermoplastic resin 13 and a polymer covering it. It contains 1 to 20 C, 6% additives. In this state, when a compressive force is applied to the compression molding die 11 to compress the thick-walled base material 12, the thick-walled base material 12 is biaxially oriented (3-2). After the compression molding die 11 is cooled and the molded product 13 is cooled and solidified, it is removed from the die and the surface polymer is peeled off from the molded product 1.
An iIqII oriented molded product is obtained.

An even better biaxially oriented molded product can be obtained by coating the inner surface of the compression molding die with a fluororesin such as polytetrafluoroethylene. By this compression molding method, a 211id+ oriented sheet with a thickness of 1 to 10 mm and a stretch ratio of 15 to 7 times in terms of area ratio can be favorably molded. This IJ: cotton molding method is particularly suitable for molding thick-walled biaxially oriented trunks of one or more cylinders.

FIG. 4 shows an apparatus for forming thick 2 dlr oriented sheets by extrusion according to the present invention. In FIG. 4, the thermoplastic resin heated and plasticized by the first extruder 14 is press-fitted into a die 15 in the form of a sheet. The polymer heat-plasticized in the second extruder 17 is press-fitted into the die 5 to become the surface layer of the thermoplastic resin, and in the A section of the die 15 it becomes a 3-layer notebook-like thick-walled molded product. Part A is cooled, and here the three-layer sheet-like thick-walled molded body is cooled to a humidity that is above the glass transition temperature and below the melting point of the thermoplastic resin.

Portion A requires a length that allows the resin to be cooled almost uniformly, and after cooling, it may be heated slightly to make the temperature uniform, if necessary.

Next, the three-layer molded body is biaxially oriented using part B of the die. The die has a structure in which the thickness becomes thinner in the B portion and 11J widens. Figure 5 shows the change in flow of the molded product in part B.

The inner thermoplastic resin layer of the molded body flows in a plug flow due to the action of the surface polymer layer, and is simultaneously biaxially oriented in the flow direction and in the direction perpendicular to the flow direction.

The force for biaxially orienting the molded body is the extrusion force from the extrusion molding machine. /10
It is preferably 1,150 or less, and 1,000 or more, preferably 5,000 or more.

The biaxially oriented molded body is further cooled in the C part of the die,
Preferably, the resin exits the die after being cooled to below the glass transition humidity of the resin. If necessary, it is further cooled with cold water 18, passes through a rubber roll 16, and becomes biaxially oriented. In order to uniformize the sheet coming out of the die 15, it is also effective to provide resistance to the rotation of the rubber roll to prevent the sheet from coming out.

It is particularly effective to add additives that favor i'fl) properties to the polymer, and it is preferable to add 1 to 20% by weight of the additives.

If the inner surface of the die is coated with a fluororesin such as polytetrafluoroethylene, the flow inside the die will be even better.
The biaxial orientation is stable and good in row 11 tL.

When the surface polymer of the sheet that has come out of the rubber roll is peeled off, a biaxially oriented sheet of thermoplastic resin is obtained.

This extrusion molding method is particularly effective for forming thick biaxially oriented sheets/r with a thickness of 1 mm or more at a stretching ratio of 15 to 7 times in area ratio. Suitable for l1ql+ oriented sheets.

The formed biaxially oriented sheet can then be further formed into a corrugated sheet, if desired. Such corrugated sheets are also included in the sheet of the present invention.

FIG. 6 shows a method for forming biaxially oriented fibers by a similar method.

In FIG. 6, the thermoplastic resin heated and plasticized in the first extruder 4 is press-fitted into a die 19 in the form of a tube. The polymer extruded by the second extruder 17 is press-fitted into the die 19 and becomes the front and back layers of the thermoplastic resin tube, resulting in a pipe with a three-layer structure.

The pipe becomes a constant thick-walled tube at the D portion of the die 19, and is cooled to a temperature above the glass transition temperature and below the melting point temperature. The D portion of the die 19 needs to be long enough for the resin to be sufficiently cooled. For uniform cooling, it is preferable to provide appropriate cooling sections and heating sections in the D section.

Next, in the E portion of the die 19, the diameter of the pipe is enlarged, the wall thickness is reduced, and the pipe is biaxially oriented. In part B, the resin layer in the inner layer of the pipe has a flow similar to a plug flow, and the thick-walled pipe is extruded, expanded in diameter, rolled, and biaxially oriented simultaneously in the flow direction and diametrical direction.

2: The I#l+ oriented pipe is further cooled in the D portion of the die, preferably to below the glass transition temperature of the resin, and exits the die 19.

The rubber roll 21 is further cooled with cold water 20 as needed.
It becomes a biaxially oriented vibrator. In order to extrude the pipe uniformly, resistance is applied to the rotation of the rubber roll 21, and the die]9
It is effective to apply counter pressure to the pipe exiting the pipe.

In pipe molding, biaxially oriented molding can be achieved even better by coating the inner surface of the die with a fluororesin such as polytetrafluoroethylene, as in sheet molding.

According to the present invention, a three-layer body made of two types of resins can also be oriented and molded favorably.

FIG. 7 shows an apparatus for biaxially aligning a three-layer body made of two types of resins in the same manner as shown in FIGS. 4 and 5. In FIG. 7, the first resin heat-plasticized by the first extruder 22 is press-fitted into a die 25. As shown in FIG.

The second resin heat-plasticized by the second extruder 23 is press-fitted into the die 25 and becomes the surface layer of the first tree finger to form a three-layered resin. Furthermore, a low viscosity polymer is extruded from the third extruder 24 onto the surface of the three-layered body to coat the three-layered resin body.

Next, the film is cooled, biaxially stretched, and further cooled in the same manner as in FIGS. 4 and 5, and exits from the die 25. The polymer 26 is peeled off from the 211ζ11 stretch sort, and a good three-layer biaxial stretch 27 is obtained.
is obtained. In this case, it is preferable that the first resin has a higher viscosity than the second resin within the die.

The present invention can be successfully applied to various types of extrusion molding in addition to biaxially oriented molding, and some further application examples will be shown below.

In order to extrude a foam by extrusion molding, a resin having an appropriate viscosity in which a foaming agent is uniformly dispersed is extruded into the atmosphere through a die.

It has been said that there is a viscosity range suitable for foam molding, and that it is essential to extrude within this range. When the viscosity is lower than the appropriate viscosity range, the foaming gas breaks through the foaming cells and escapes into the atmosphere, and when the viscosity becomes high, it becomes difficult to extrude from the extrusion die, and the expanding force of the foaming gas no longer works.

The viscosity of polystyrene and the like changes slowly with temperature, and by adjusting the temperature appropriately, the viscosity can be brought to an appropriate range for foam molding. However, it has been said that for resins such as polypropylene and polyethylene whose viscosity changes rapidly, it is difficult to bring the viscosity to a range suitable for foaming by adjusting the temperature.

Until now, methods such as intermolecular cross-linking by electron beam irradiation, addition of chemical cross-linking agents, etc. have been used to slow the temperature-induced viscosity changes of polypropylene, polyethylene, etc., and cross-linked polyethylene, etc. have been used for foam molding. It's here.

However, such a crosslinking reaction involves various problems such as an increase in processing costs, and there is a need for a method for stably performing extrusion foam molding without performing a crosslinking reaction.

As a result of various studies, it was discovered that the molding method of the present invention is very suitable for extrusion foam molding. That is, by using the method of the present invention, it is possible to extrude resin in a high viscosity state, which conventionally required only one extrusion. By extruding into the atmosphere, foam extrusion and foam molding can be performed well.

Since extrusion in a high viscosity state can be easily carried out, the area over which the temperature of the resin can be uniformly adjusted can be lengthened, and as a result of being able to uniformize the resin temperature, a good, uniform foam can be obtained.

If the resin is extruded at a lower temperature and at a high viscosity that does not cause foaming, a foaming resin in which the foaming agent is dissolved in the resin can be obtained. Good for producing foaming resin pellets impregnated with a large amount of physical foaming agent. Low boiling point substance J: lJj blowing agent,
It has been difficult to manufacture foaming resins such as resins with high softening temperatures, and this problem has been solved.

Furthermore, the present invention allows for molding that has been difficult with conventional extrusion foam molding.
It can also be applied to ultra-high foam molding with a foaming ratio of 50 times or more.

In other words, since the resin can be extruded with a high viscosity, it is no longer possible to extrude stably with a larger amount of blowing agent than before, and a foam with a high expansion ratio can be extruded.

Even in foam molding, if the inner surface of the die is coated with a fluororesin, the flow within the die will be even better, and a good foamed product will be obtained.

Foam extrusion molding will be explained using FIGS. 8 and 9. 8th
The figure shows crystalline resins such as polyethylene and polypropyref,
It is a graph showing the relationship between viscosity and temperature of amorphous resin such as polystyrene. As is clear from the figure, the viscosity of the crystalline resin changes rapidly in the foamable viscosity range, so the temperature range H in which the foamable viscosity is achieved is very small. On the other hand, the suitable temperature range G for foaming amorphous resin is wide, and therefore foam molding is easy. The present invention can be favorably used for extrusion foam molding of resins having a narrow foaming temperature range.

FIG. 9 shows an apparatus for molding extruded foam according to the method of the present invention.

In FIG. 9, a thermoplastic resin containing a foaming agent (preferably a crystalline resin in the present invention) is heated and plasticized in a first extruder 28, cooled to a temperature suitable for foaming as much as possible, and then transferred to a die. Press fit into 29.

A polymer covering the resin is extruded by the second extruder 30 and press-fitted into the interface between the inner surface of the die and the resin to cover the resin.

The part of the die brings the entire resin to a uniform temperature suitable for foaming.

In order to maintain a uniform temperature suitable for foaming in both the surface and inner core of the resin, the length of the K section must be long enough, and the pressure loss that occurs locally is generally large due to the fairly high viscosity. . In the present invention, since the pressure loss in the K part can be significantly reduced by the coated polymer, it is possible to make the K part sufficiently long, and as a result, the foamable resin at a uniform foaming temperature can be pressed. I can put it out.

The extruded foamable resin becomes a foam 31. The polymer 32 on the surface can be peeled off if necessary.

In the case of foamable resin or high-density polyethylene, the surface-coating polymer does not have the adhesive properties of polyethylene (polyolefin, such as polypropylene kneaded with a large amount of lubricant, can be used well. When the resin is polypropylene, a polymer such as polyethylene kneaded with a large amount of lubricant can be used satisfactorily.

Furthermore, in the present invention, polyethylene terephthalate having a large molecular weight,
For example, polyethylene terephthalate having [η] of 016 or more (measured at 25°C with a mixed solution of phenol/tetrachloroethane weight ratio 60/40), preferably 09 or more, mixed with various blowing agents can be used.

Next, another application example of the present invention will be described.

Molded articles made of ultra-high molecular weight polyethylene with a weight average molecular weight of 1 million or more are excellent in wear resistance, lubricity, impact resistance, chemical resistance, sound absorption, etc. However, molding processability is poor, and so far no satisfactory molded product has been obtained. For example, it is molded by powder compression molding, ram extrusion molding, calender molding, etc.

The extrusion molding method of the present invention enables extrusion molding of a resin in a high viscosity state, and can satisfactorily extrude a highly viscous body of ultra-high molecular weight polyethylene. The molding method of the present invention is suitable for molding various ultra-high molecular weight materials such as polyethylene, polyzolopyrene, and ABS resin, which have been difficult to mold in the past.

Trying to flow an ultra-high molecular weight polymer in a laminar flow through an extrusion die requires extremely high extrusion pressure, and when high extrusion pressure is applied, melt fractures occur, making it difficult to obtain a good extrusion molded product. There are many cases where there is no.

By using the method of the present invention, that is, by covering the bulk polymer material with a low-viscosity polymer during molding, the ultra-high molecular weight material can be flowed in a plug flow state in the die, reducing the extrusion pressure. The molded product can also be obtained in good condition. According to the present invention, it is possible to extrude sheets, pipes, irregularly shaped products, etc. of ultra-high molecular weight polymers, which have been difficult to mold up to now.

Heat-decomposable resins that easily undergo thermal decomposition, such as polyvinyl chloride and polyvinylidene chloride, are required to be molded at as low a temperature as possible. Until now, these resins have been molded at low temperatures by adding large amounts of heat stabilizers, plasticizers, etc. to lower the viscosity and improve moldability.

The method of the present invention allows molding in a high viscosity state, and can be molded at low temperatures by reducing the amount of stabilizers, plasticizers, etc. added.

When molding ultra-high molecular weight polymers or easily heat-decomposable resins, coating the inner surface of the die with a fluororesin such as polytetrafluoroethylene improves the flow within the die, resulting in more favorable results. is obtained.

Furthermore, the present invention can be used for roll forming. In a molding method in which the temperature of a thermoplastic resin extruded by an extrusion molding machine is adjusted to above the glass transition temperature and below the melting point temperature of the resin, and then inserted between rolls heated to approximately the same temperature for rolling orientation. , 1/10 or less of the viscosity of the thermoplastic resin during rolling 1
A good oriented sheet can be obtained by molding the thermoplastic resin while covering it with a polymer of 000 poise or more.

The viscosity during molding described in the present invention is, in biaxially oriented molding,
It is the viscosity when biaxially oriented, for example, 2
In the axial orientation, the viscosity is in the 3rd section of Figure 4. In foam extrusion molding, the viscosity is from the resin cooling part to the exit part of the die, in the molding of easily thermally decomposable resins, the viscosity is the highest temperature part of the die, and in the extrusion molding of ultra-high molecular weight materials, it is the viscosity in the center of the die. The viscosity is the viscosity from the point to the outlet, and in the case of roll rolling, it is the viscosity on the roll. In both cases, viscosity is the most important part during molding.

The thermoplastic resin mentioned in the present invention can be any thermoplastic resin that is generally used for extraction molding or compression molding.
Furthermore, thermoplastic resins that can be heat-plasticized using an extrusion molding machine can be used. For example, polystyrene, styrene-acrylonitrile copolymer, ABS resin, polyvinyl chloride, polymethyl methacrylate-1, polycarbonate, polyester, nylon, boron ether, or a blend or copolymer of these resins. be.

The polymer mentioned in the present invention is particularly preferably a polyolefin having a low glass transition temperature, such as polyethylene, polypropylene, various modified polypropylenes, etc., but a polymer having a viscosity within the range mentioned in the present invention can be widely used.

Various physical foaming agents and chemical foaming agents can be used as the foaming agent described in the present invention. Examples include hydrocarbon compounds such as propane, butane, pentane, and hexane, chlorinated hydrocarbon compounds such as chloromethane and dichloromethane, various freons, azodicarboxylic acid amide, and sodium bicarbonate.

In the present invention, the temperature below the glass transition temperature (2111+drawing temperature) and -1 melting point temperature is generally a temperature suitable for orienting a synthetic resin, and the preferable temperature range differs depending on the resin. For crystalline resins, the temperature above which crystallization occurs,
The temperature is preferably below the temperature at which the crystals melt. For non-crystalline resins, the temperature is below the molding temperature of general injection molding, extrusion molding, etc., preferably below (the molding temperature -30°C) and above (glass transition temperature +10°C).

Biaxially oriented molding according to the method of the present invention is suitable for molding thick molded products, preferably 1 mm or more, more preferably 1.5 mm or more. It is particularly suitable for forming biaxially oriented molded products such as thick sheets and pipes.

By the method of the present invention, an oriented molded product having an arbitrary stretching ratio can be obtained, but a stretching ratio of 15 times to 10 times (thickness ratio) is preferable due to the effects of stretching.

The method of the present invention facilitates the molding of thermoplastic resins in a high viscosity state, making it possible to favorably perform biaxially oriented molding, foam molding, molding of ultra-high molecular weight materials, molding of easily thermally decomposable resins, etc. The effect is strong.

Example 1 A 20 mm thick sheet-like preform of polymethyl methacrylate with a weight average molecular weight of 4.4 million (+1). Furthermore, 3% by weight of stearic acid was kneaded into l mm thick polypropylene of Ml 4 on the front and back of the preform. The three-layer preformed product (2) to which the sheet was attached was subjected to two-layer orientation molding by compression molding.Using the molding apparatus shown in Figure 3, the inner surface of the compression die was coated with industrial material, 26, A;, 6,
The coating and preform were coated with polytetrafluoroethylene using the Teflon coating described in 97.
After heating to 0°C, place the pre-captured molded product in the die and
A biaxially oriented sheet was formed by compressing it to a thickness of mm and stretching it 1 to 5 times the thickness. 3 with polypropylene on the front and back
The layer preform (2) is well and uniformly stretched.
Although an axially oriented sheet was obtained, the single layer preform +1+ could not be stretched uniformly, and severe brittle fracture occurred, especially at the sheet edges.

Example 2 A biaxially oriented sheet was molded by extrusion using the molding apparatus shown in FIG. As the core resin, a copolymer acrylic resin of methyl methacrylate and methyl acrylate (5% by weight of methyl acrylate, weight average molecular weight 150,000),
As the surface layer resin, a resin in which 3% by weight of stearic acid was kneaded into Mj4 polypropylene was used. The first extruder and the second extruder extrude the surface resin and the inner core resin to form a thick three-layer body with the inner core of 20 mm and the front and back layers of 1 layer using the 4 parts of the die.
Cooled to 50°C. The inner surfaces of the four parts, B part, and C part of the die were coated with polytetrafluoroethylene using Teflock processing. Biaxial orientation was performed five times in the B part of the die, and cooled in the C part to obtain a biaxially oriented three-layer sheet with a thickness of 4 mm. A good biaxially oriented acrylic sheet was obtained by peeling off the polypropylene surface layer. Similarly, a single-layer acrylic resin without polypropylene on the surface layer was subjected to biaxially oriented molding, but the flow in the die was unstable, and uneven flow due to poor flow was observed on the surface of the biaxially oriented sheet obtained. However, a uniform biaxially oriented sheet could not be obtained.

Example 3 A three-layer biaxially oriented sheet was molded by extrusion molding as described in the specification using the molding apparatus shown in FIG. In FIG. 7, a first extruder extruded polycarbonate, a second extruder extruded polymethyl methacrylate, and a third extruder extruded polypropylene kneaded with 3% by weight of stearic acid. Inside the die, the inner core polycarbonate
0 thickness, 5 each from polymethyl methacrylate on the surface layer
mm thick, and polypropylene is 1 mm thick. The extruded biaxially oriented sheet was 4 mm thick and 5 times stretched.

Example 4 A foam was extrusion molded using the molding apparatus shown in FIG. 9 by the molding method described in the text. MI 0.5 (ASTMD)
Freon 1 as a blowing agent in polypropylene (238)
A foamable resin containing 5% by weight of 14 and 05% by weight of a nucleating agent was used, and low density polyethylene M was used as the surface coating polymer.
A polymer obtained by kneading 5% by weight of stearic acid into 6520 was used. The foamable resin was press-fitted into a die using an extrusion molding machine at a temperature as low as possible, and after being cooled uniformly in the inner part of the die, it was extruded out of the die and foamed to obtain a foam. When extruding a foamable resin without surface coating with a polymer, the flow resistance in the die was large and the extrusion could not be performed.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the flow state of resin and polymer in the die. FIG. 2 is a graph showing the relationship between temperature and viscosity of various thermoplastic resins or polymers. FIG. 3 is an explanatory view showing the process of molding a biaxially oriented thread by compression molding. FIGS. 4 and 7 are cross-sectional drawings showing an apparatus for forming a 2IIIIII oriented sheet by extrusion molding. FIG. 5 is an explanatory diagram showing an enlarged stretching portion for forming a biaxially oriented sheet using the apparatus shown in FIG. 4. FIG. 6 is a cross-sectional drawing showing an apparatus for forming a 2+li+b oriented pipe by extrusion molding. FIG. 8 is a graph showing the relationship between resin viscosity and temperature. FIG. 9 is a cross-sectional drawing showing an apparatus for molding a foam by an extrusion method. 1. Speed, 2.3.6.8... Speed curve (flow curve)
, 4, 26.32 Polymer, 5-Thermoplastic resin, 7
・Thickness of polymer layer, 9...- Fastest flowing part, 1
0...Covering layer, 11...Compression molding die, 12...
Thick-walled base material, 13... Molded product, 14,] 7.22.
23.24.28.30...Extruder, 15, 19.
25.29 - Die, 16.21...-Rubber roll, 18.20... Cold water, 27... Biaxially stretched sheet, 31... Foam. Applicant: Asahi Kasei Kogyo Co., Ltd. Agent Yutaka 1) Yoshio Procedural Amendment April 18, 1980 Kazuo Wakasugi, Commissioner of the Japan Patent Office 1 Indication Patent Application No. 1983-234240 2 Name of Invention New Molding Method 3 Amendment Relationship with the Nagisa Incident Patent Applicant: 1-2-6 Dojimahama, Kita-ku, Osaka-shi, Osaka Prefecture (003) Teru Miyazaki, Representative Director and President of Asahi Kasei Industries Co., Ltd. 4 Agent: 1-4-1 Yurakucho, Chiyoda-ku, Tokyo Sanshin Building, Room 204, Telephone: 501-21386 Contents of Amendment (1) The following sentence should be inserted next to "Preferably..." on page 10, line 8 of the specification. [Generally, the coefficient of dynamic friction between the steel (S45C) that makes up the die and various resins is the following value. (lubrication, u912 (196
6) Quoted from 485) Polymethyl methacrylate
0568 polystyrene 0368A
ES resin 0366 polyvinyl chloride
0219 Polypropylene O: 300 High Density Polyethylene 0139 Resins with a small coefficient of dynamic friction, such as PP and PE, easily slide inside the goo and are suitable as surface layer resins. In particular, when 1゛P or PE is applied as a surface layer to a material such as PMMA, which has a large coefficient of friction, the effect becomes remarkable. (2) Same No. 14
Insert the following text between the first and second lines of the page. ``The most preferable surface layer resin used in the compression molding method is one in which the resin viscosity changes gradually due to temperature by partially crosslinking a soft polyolefin such as PE or PP. In addition, in the compression molding method, it is preferable to mold with the surface layer resin covering the entire surface of the thick-walled base.For example, the entire thick-walled base is coated with PE,
A method of covering with a Seelink sheet such as PI) can be used. More preferably, the inside of the covering sheet is evacuated by vacuum packaging, and then the shrink packaging is performed to achieve good molding. (3) Insert the following sentence between lines 19 and 200 on page 18. A 15-layer biaxially stretched sheet is formed, the outermost layer is peeled off, and 3
Forming a biaxially oriented sheet of layers can also be performed by compression molding. When forming a 5-layer biaxially stretched sheet by extrusion molding or compression molding, the innermost core layer (third
It is preferable that the resin of the layer) has a higher softening temperature and/or a higher viscosity during molding than the resin of the white coat layer (second layer and fourth layer). In other words, the resin in the innermost core layer (third layer) has a higher molecular weight or has a higher zetaization temperature and is more heat resistant than the resin in the white coat layer (second and fourth layers). Preferably using resin 3,” (4)
Insert the following sentence between the second and third lines of page 19. ``With the extrusion molding of the present invention, 1 i1i+I+ orientation molding can be performed in the same way. Uniaxially oriented round bars, etc. can be formed well. A strong linear body can be obtained by forming a uniaxially oriented round bar such as -1. "Extrusion foam molding" is corrected to "foam extrusion molding." (6) Same page 23] In the 8th line, "It can be used." [Furthermore, it can be similarly applied to foam molding of nylon, nylon-modified resin, etc. ] Insert. (7) Same page 26, 16-] "Extraction molding" in line 7 is corrected to "extrusion molding."

Claims (1)

[Claims] (1) Compressing the heated thermoplastic resin in a die;
Or, in extrusion molding, compression molding, or rolling molding, which is formed by extruding inside a die or rolling with a roll, the weight of 1000 voids or more is 1/10 or less of the viscosity at the time of molding of the thermoplastic resin. A new molding method characterized by combining and molding while covering with thermoplastic resin. (2) The polymer has a viscosity of 1750 or less (
3) The polymer is blended with additives that have excellent lubricity.
Molding method. (4) The molding method according to any one of claims (1) to (3), wherein the thermoplastic resin and the polymer can be easily peeled off after molding. (5) The molding method according to any one of claims C11 to (4), wherein the polymer is a polyolefin. (6) Claims (1) to 1, wherein the thickness of one side of the polymer coating layer is 1710 times or less of the thickness of the thermoplastic resin layer.
The molding method according to any one of (5). (Claims (1)-(
The molding method according to any one of item 5). (8) After heating the thermoplastic resin preform to a temperature above the glass transition temperature and below the melting point of the core resin, it is compressed in a die heated to approximately the same temperature to achieve 2 i11+ orientation, and then cooled. Claims (1) to (7) characterized in that the sheet is produced as a biaxially oriented sheet with a thickness of 1 to 10 recesses.
) The molding method according to any one of the above items. (9) After controlling the temperature of the extruded thermoplastic resin to a temperature above the glass transition temperature and below the melting point temperature of the core resin, it is biaxially oriented in a goo under extrusion pressure to form a biaxially oriented sheet with a thickness of 1 to 10 mm. Claims (1) to (1) (The molding method according to any one of the following items. 1)-(7)
A method for forming an extrusion molded product as described in any of the above. (11) A method for molding an extruded foam according to any one of claims (1) to (7), which contains a thermoplastic resin or a blowing agent. FIZ A method for molding an extrusion molded product according to any one of claims (1) to (1), wherein the thermoplastic resin is easily thermally decomposable. After bringing the resin to a temperature above the glass transition temperature and below the melting point, 1 is pressed between rolls heated to approximately the same temperature, rolled, and oriented. The method for forming an oriented sheet according to item 1.