JPS61127334A - Molding method of polyamide-imide sheetlike article - Google Patents

Abstract

PURPOSE:To obtain a sheetlike article having no anisotropy in mechanical properties and is superior in mechanical properties themselves, by taking off the sheetlike article having polyamide resin possessing a repeating unit to be shown by an expression 1 for its main structural unit for its main material while heat treatment is being applied to the sheetlike article. CONSTITUTION:When a composite having polyamide resin shown by an expression 1 (in the expression, Ar shows a trivalent aromatic group including at least one carbon 6 member ring, R shows a bivalent aromatic group and/or aliphatic series residue and R' shows a hydrogen or methyl group or phenyl group.) for its main material is melted, extruded through a cap by making the same into a sheetlike state and a sheet is taken off by a cooling roll at a draft ratio of 1.2-20 for cooling and curing, the sheet between the cap and cooling roll is heat-treated at 180-270 deg.C by a heat treatment roll provided between the cap and cooling roll. A polyamide-imide sheetlike article obtained in this manner is used for use making use of its excellent heat resistance, sliding characteristics, electrical characteristics and chemical resistance such as a heat insulation material, insulating material, gasket and packing.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is applicable to applications that take advantage of its excellent heat exchange properties, sliding properties, electrical properties, and chemical resistance, such as heat insulating materials.

The present invention relates to a sheet material mainly made of polyamide-imide resin used for insulating materials, gaskets, backings, etc.

[Prior art]

A method for producing a polyamide-imide resin sheet is usually a method in which the resin is extruded onto a casting drum and cooled, or a method in which the resin is gradually cooled in air and then taken off. However, since the polyamide-imide resin has an extremely high melt viscosity, it easily becomes oriented due to the draft during take-up, and has the disadvantage that the mechanical properties in the width direction deteriorate rapidly.

Therefore, in order to obtain a sheet-like product with well-balanced mechanical properties in the longitudinal and width directions, the draft ratio could only be increased to about 1.1 at most.

[Problem to be solved]

When you want to obtain sheets of various thicknesses.

Since the draft ratio cannot be changed, the mouth lip gap must be changed each time, and no improvement in productivity can be expected.

[Means to solve the problem]

The present invention has the following configuration to achieve the above object.

Namely.

In formula C, Ar is a hexavalent aromatic group containing at least one carbon 6-membered ring, R is a divalent aromatic and/or aliphatic residue, and R/ is hydrogen, a methyl group, or a phenyl group. A composition mainly composed of a polyamideimide resin having repeating units of
．． 2 to 2.0, the sheet between the cap and the cooling roller is heat-treated at 180 to 270° C. with a heat treatment roll provided between the cap and the cooling roll. It is characterized by a method of forming a sheet-like product.

The composition mainly composed of polyamide-imide resin in the present invention is not particularly limited, but preferably 65 wt% or more is aromatic polyamide-imide resin, and more preferably 80 wt% or more is aromatic polyamide-imide resin. Bye.

The aromatic polyamide-imide resin used in the present invention has 50 to 50 to
having 100 mol% (preferably 70 to 100 mol%),
Other binding units in an amount of less than 50 mol% (preferably 30 mol%, n7%), such as the following (II) or (
III) Aromatic polymers which may contain polyamide and/or polyimide units having the general formula III).

Structures CI) and (III) in which a portion of the imide bond remains in the form of an amic acid bond as its ring-closing precursor are also included. Here, Ar is a trivalent aromatic group containing at least one carbon 6-membered ring, and its current divalence means that two carbonyl groups are bonded to adjacent carbon atoms in the benzene ring of the Ar group. It is characterized by being. Although not particularly limited, the number of carbon atoms is usually 6 to 50. for example.

It is possible to specifically enumerate structures such as:

Ar' is a divalent aromatic group or aliphatic group containing at least one 6-membered carbon ring, such as, for example. Ar'' is an aromatic group in which at least one tetravalent carbonyl group containing a 6-membered carbon ring is connected;
each is characterized by being bonded to adjacent carbon atoms in the benzene ring of the Ar″′ group, e.g.

etc. The number of carbon atoms represented by Ar' and Ar/' is usually selected from the range of 6 to 50. R is a divalent aromatic and/or aliphatic residue, and the number of carbon atoms is usually 6 to 50 for aromatic residues and 1 to 5 for aliphatic residues.
It is 0. A specific example is (CH) t CC
Hz) n-1, etc. Further, R' is hydrogen, a methyl group or a phenyl group.

The aromatic polyamideimide resin having the structural unit formula CI) used in the present invention can be produced by reacting a combination of dimethylformamide, dimethylacetamide, N-methylpyrrolidone, cresol, etc. in a polar organic solvent. In addition, the introduction of the structural unit (II) polyamide unit and/or (I[) polyimide unit which can be partially copolymerized to η as the main component, This is achieved by substituting and reacting raw materials in the structure of polyamideimide.

Among them, a typical polyamide-imide resin is sold by Amoco Corporation in the United States.

It has a molecular structure of These manufacturing methods are disclosed in detail in British Patent No. 1056→64 filed by Standard Oil Co., Ltd., US Patent No. 3,661,832, and the like. Other methods for producing polyamide-imide resins are also disclosed in U.S. Patent No. 56699.
No. 37 (Bayer AG), French Patent No. 2°09645
No. 4 (Ceralac Fabric Co., Ltd.), French patent No. 1
No. 515066 (Dupont Company), Special Publication No. 1831/1973
No. 6 (Hitachi Chemical), British Patent No. 1181446 (Hitachi Chemical), French Patent No. 2086324 (General Electric Company), Special Publication No. 5072 (Nitto Denko), U.S. Patent No. 1625911 ( Mopil Oil Co., Ltd.), British Patent No. 1277834 (Mornboulin Co.), British Patent No. 1032649 (Westinghouse Co.), and Japanese Patent Publication No. 49-4077 (Toshisha Co., Ltd.).

' In the present invention, the polyamide-imide resin is added with reinforcing agents such as glass fiber and carbon fiber, flame retardant improvers such as calcium carbonate and magnesium carbonate, electrical property improvers such as clay, mica, graphite, and carborundum. An antifriction agent or a good fluidizing agent such as aromatic polyamide or polyphenylene sulfide may be added as necessary in an amount of 55 wt % or less based on the total amount of the nine compositions.

In particular, it is desirable to add less than 2 Qwt% from the viewpoint of mixing ratio and impact resistance.

The extruder used in the present invention may be any known extruder and is not particularly limited.
36. It is preferred to use an extruder equipped with a screw having a compression ratio of 1.2 to 4.5.

The draft ratio in the present invention is defined as the ratio (A/B) between the gap A of the metal lip slit and the obtained sheet thickness B. In the present invention, the draft ratio is set to 1.2 to 2.0 and the sheet shape I need to pick up things. This is when the draft ratio is less than 1.2.

The orientation relaxation effect caused by the heat treatment roll is not significant.

This is also because it is somewhat difficult to take off and the flatness is poor.

If it exceeds 2.0, the sheet-like material will have poor spinnability, resulting in holes or increased thickness unevenness, and in severe cases, the sheet-like material will break, which is not preferable.

The material of the cooling roll in the present invention is not particularly limited, but 1
Hard chrome, silicon or Teflon coated rolls, or sandblasting rolls are usually used. The cooling roll surface temperature is usually 100°C or less.
Preferably, the temperature is 80"C or less. 9 Usually, a predetermined temperature is maintained by circulating water or a refrigerant.

Further, it is preferable that the cooling roll has a nip mechanism so that the sheet can be taken up at a constant speed, but in this case, the nip roll material and temperature may be selected from the same material and temperature conditions as the co-cooling roll.

Although the speed of the cooling roll is not particularly limited, it is preferable to take it off at a speed of about 1.01 to 1.1 with respect to the speed of the heat treatment roll. By doing so, the sheet flatness is improved.

In the present invention, one or more heat treatment rolls are provided between one die and the cooling roll. The upper limit of the number of heat treatment rolls is not particularly limited, but is usually 5 or less. In the present invention, at least one of the heat treatment rolls is 18
Must be maintained at 0-270°C. In particular, it is particularly suitable that the roll closest to the die is kept at 180 to 270°0, and the temperature gradually decreases as it approaches the cooling roll. Alternatively, the slow cooling step may be performed by natural heat radiation. Further, it is preferable to have a nip mechanism in order to improve adhesion to the heat treatment roll and to reduce fluctuations in draft ratio. Although steam may be used as the heating medium for the heat treatment roll, it is preferable to use side heating oil such as silicone. If the roll surface temperature is lower than 180°C, distortion due to melt orientation remains,
This is not preferable because anisotropy in the mechanical properties of the sheet remains and the mechanical properties themselves become insufficient. On the other hand, if the temperature exceeds 270°C, the sheet tends to stick to the roll, which may cause the sheet surface to become rough or cause new anisotropy in mechanical properties due to the force when separating from the roll, which is not preferable.

The roll material is not particularly limited, but silicone or Hachifuron coated rolls, hard chrome plating rolls, sandblasting rolls, etc. can be used. The contact time between the heat treatment roll and the sheet material is not particularly limited, but 1
Usually 0.3 seconds or more.

Preferably, it is necessary to make the contact for 1 second or more, more preferably for 2 seconds or more. The upper limit of the contact time is not particularly limited, but is usually 5 minutes or less.

The sheet-like material in the present invention has a thickness of 0.1 to 5 mm, but a sheet-like material with a thickness of 0.10 mm to 1.8 mm is preferred because the effects of the present invention are more pronounced. .

Next, regarding a typical manufacturing method of the sheet-like product of the present invention,
As a representative example of polyamide-imide resin, Amoco's "Token" will be used for explanation, but the present invention is not limited thereto.

After blending various additives as necessary with "Token" 4205L (powder), L/D-18 to 56. Pelletization is performed at 600-660°0 using an extruder equipped with a screw with a compression ratio of 1.2-4.5. After drying the pellets to a moisture content of 0.01 to 1.0%, the compression ratio was 1.2.
~600~ using an extruder equipped with ~45 screws
Melt at 380°C.

Next, the molten resin was passed through a nozzle heated to 600 to 380°C to form a sheet, and then the draft ratio was set to 1.
1 to 2.0, at least one roll is brought into contact with a heat treatment roll (one or more rolls) set at a surface temperature of 180° to 270°C, and then taken off while being brought into contact with a cooling roll. The sheet-like product thus obtained is used after being subjected to post-curing (thermal curing treatment) under predetermined conditions.

Post-cure conditions are determined depending on the resin by referring to technical data, etc.9 For example, in the case of "Token", it is performed using a hot air opener and dried at 165°C for one day.

It is carried out at 245°C for one day, and further at 260°C for about one day to one week.

In addition, once 120 kg/c-2 of °Torlon'' is used in one holder.
above, preferably 180 kg/cI112 or above (however, the upper limit is not particularly defined, but 1 usually 800 x 7 cm)
119 kg/cm during the period from when the above-mentioned pressure of 120 kg/cm or more is applied until the pressure is reduced to atmospheric pressure by discharging, that is, during the discharging process. If the time required for the resin composition to reach atmospheric pressure (when the resin composition comes out of the die) from , is suitable because it allows stable take-up even at a high draft ratio. The pressure in this case can be measured directly using a pressure gauge.1. If actual measurement is difficult, calculation may be performed using a known formula and the polymer viscosity determined using a flow tester.

In addition, the time required for dispensing can be determined directly from the passage time of the colored polymer using a nozzle equipped with a peephole.
If actual measurement is difficult, calculate the volume (cs) of the area from 1.19 gun/■2 to atmospheric pressure from the drawing.

The value is divided by the discharge amount (36/sea). In this case, the point at which the pressure is 119 kg/cm2 is calculated from a known formula and the polymer viscosity determined by a flow tester.

In order to create the high-pressure conditions and pressure-lowering conditions shown in the present invention in the mouthpiece, it is necessary to reduce the capacity of the manifold part of the known mouthpiece and to reduce abnormal retention. It is particularly preferable that the shape is an inverted triangle. Also, it is better to make the land length longer in order to increase the mouth pressure.

Furthermore, since the resin has a high viscosity and the pressure difference in the width direction in the manifold portion cannot be ignored, the pressure loss in the land portion changes in the width direction. Specifically, it is preferable to change the land length or the slit gap in the width direction. The cap used in the present invention is preferably a coat hanger type cap or a fishtail type cap, but it is more preferable to select a coat hanger die because the distortion caused by the internal pressure of one cap is small. Specific dimensions can be designed in various ways, and are not particularly limited, for example, width 150 to 2000.
In the case of a mm mouthpiece, the cross-sectional area of the central part of the manifold is 10~
2003", preferably 30-9032, central land length 20-500mm, preferably 40-150III
It may be set to llII.

Note that the melt extrusion device with two nozzles and the cooling roll applied to the present invention are all known.

[Effect]

By heat-treating a sheet-like material mainly made of polyamide-imide resin and then taking it off, it is possible to obtain a sheet-like material that has no anisotropy in mechanical properties and also has excellent mechanical properties.

[Method of measuring characteristics]

In addition, the measuring method and evaluation criteria of the characteristics in the present invention are as follows.

(1) Toughness: A sample with a width of 10 mm and a length of 100 mm was pulled at a tensile speed of 300 + nm/min using an Instron type tensile tester, and its breaking strength (lcg/a2
), the elongation at break (%) was measured, and breaking strength x elongation at break was used as a parameter for toughness (chaos%/m1lo2). The elongation at break in both the longitudinal and width directions is l'-
QJ of less than 150 was judged as "x".

(2) Smoothness: Determined by sensitivity test. If it is smooth to the touch, mark it as "○", and if it is rough or rough, mark it as "x".
It was determined that

〔Example〕

Hereinafter, embodiments of the present invention will be described based on Examples.

Examples 1-4. Comparative examples 1 to 6 Amoco ■1 Torron''4203L powder.

After compressing to a moisture content of 0.01 to 0.06, the compression ratio was set to 1.
Melt at 340'O using an 8°L/D-28 screw and extrude through a fishtail die at 340°C.

In this case, the 9-metal lip portion slit gap is 1.5wn. The draft ratio of the extruded sheet material (same as between the metal and heat treatment rolls) 1.05.1.2.1゜5.1
．． 8, 2.1, and after the surface temperature reached 200 °C (the two heat treatment rolls were at the same speed), a cooling roll with a nip mechanism (both materials are silicone coated) with a surface temperature of 80 °C was used. Take over (Comparative Example 1. Examples 1 to 3. Comparative Example 2).

Also, with a similar take-up mechanism, the draft ratio was kept constant at 1.5,
Heat treatment roll at 250°c, 150°o, 100'c,
The angle was changed to 280°0 (Example 4, Comparative Examples 4 to 6).

Also, the draft ratio is set to 1. ．． 05, heat treatment roll 15
Comparative Example 6 was prepared at 0°C. However, the draft ratio between the heat treatment roll and the cooling roll was kept constant at 1.05.

The sheet-like material thus obtained was dried at 165° C. for one day, then heat-cured at 245° C. and 260° C. for one day in a hot air open environment, and its physical properties were evaluated.

It is shown in Table-1. As shown in Table 1, Example 9 has excellent toughness, isotropy, and smoothness, but when the heat treatment roll is at a low temperature (Comparative Examples 4 and 5) or too high (Comparative Example 6) 9. Toughness 1. Isotropy is insufficient, or smoothness is insufficient.

In addition, in the case of a low draft ratio, the effect of the heat treatment roll is not remarkable, and although it is not listed in Table 9, the flatness is insufficient and the toughness of the mouth body is also slightly insufficient (Comparative Example 1.3).

Example 5 Under exactly the same take-up and heat treatment conditions as Example 2, maximum rt'10 total internal pressure 220 kg/an'', mouth internal pressure jP & = 9 yen/
cI! The time required for the pressure to drop from 2 to the outside of the nozzle is 2
A sheet-like product was obtained as 6 sec. Evaluate this and Table-1
It was shown to. In the case of this sheet-like material, the 9 toughness is further improved and is suitable. However, the sheet version has a width of 450m.
m manifold cross-sectional area 8 C111', land length 20 coat hanger type nozzle, extrusion temperature 550°C2
Metal temperature 640°C1 Discharge amount 6.5 kg7 Hr (
7) Conducted under the following conditions.

Comparative Example 7 The heat treatment roll was removed and the draft ratio between the second roll and the cooling roll was set to 1.5, and the film was formed and heat treated in the same manner as in the example, and the obtained sheet material was evaluated. Shown in 1.

At the same time as the toughness was insufficient, although not shown in Table 2, the flatness was completely impaired, so that only a sheet-like product was obtained that was difficult to commercialize.

Claims (1)

[Claims] (1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, Ar is a trivalent aromatic group containing at least one carbon 6-membered ring, R is a divalent aromatic and/or aliphatic residue , R' represents hydrogen, a methyl group, or a phenyl group) A composition mainly composed of a polyamideimide resin having repeating units represented by the following as main structural units is melted and extruded into a sheet from a die, and the sheet is drafted. ratio 1
．． A polyamide-imide sheet characterized by heat-treating the sheet between the die and the cooling roll at 180 to 270°C with a heat treatment roll provided between the die and the cooling roll when taking the sheet at 2 to 2.0 with a cooling roll and cooling and solidifying it. A method for forming shaped objects.