JPS5891723A - Thermoplastic polyamide-imide copolymer - Google Patents

Abstract

PURPOSE:A thermoplatic polyamide-imide copolymer having both good heat stability and fluidity at 300-400 deg.C, and being injection-moldable into moldings having desirable properties, comprising four specified structural units in a specified ratio. CONSTITUTION:A copolymer consisting of structural unit (A) represented by formulaI, wherein Z is a trifunctional aromatic group, two of the three functional groups of which are bonded to the adjacent carbon atoms, structural unit (B) represented by formula II, structural unit (C) represented by formula III and structural unit (D) represented by formula IV, wherein X is -S- or -O-, wherein the structural units are present in such amounts that 1mol of (C+D) is present per mol of (A+B). A/B is 4-70mol%/96-30mol%, and C/D is 10-70mol%/90- 30mol%. When the amount of unit A is below 4mol% or above 70mol%, based on (A+B) units, the melt viscosity of the polyamideimide copolymer becomes excessively high, which is unfavorable.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a novel thermoplastic that has good thermal stability and fluidity, especially in the temperature range of 300 to 400°C, can be injection molded, and can be used to form molded products with desirable properties. This relates to aromatic polyamide (imide) copolymers.

It is already well known that an aromatic polyamideimide having excellent heat resistance can be obtained by polycondensing an aromatic tricarboxylic acid anhydride or its derivative with an aromatic diamine or its derivative. However, when the aromatic polyamide-imides that have been generally proposed for the purpose of being used as a melt-molded moon phase, the thermal stability during melt molding, the fluidity during melt molding, and the melt molding The physical properties of the body were not necessarily satisfied in terms of the 1-tal balance. On the other hand, for the purpose of improving the overall physical property balance and creating a more economically inexpensive copolymer, aromatic dicarboxylic acid anhydride or its derivative and aromatic dicarboxylic acid dichloride are used in combination as the acid component. Although various studies have been conducted regarding the method, it has not yet been possible to develop a thermoplastic polyamide-imide copolymer with satisfactory properties as a melt molding material (for example, Publication No. 8894, Japanese Patent Application Publication No. 121.397/1983, Japanese Patent Publication No. 16.90/1972
Publication No. 8, Special Publication No. 12,594, Special Publication No. 49-12, No. 4
9-13,240, Japanese Patent Publication No. 49-26,316, etc.).

For example, polyamide-imide represented by the general formula synthesized from three components of trimellitic anhydride/isophthalic acid dichloride/4,4'-diaminodiphenylmethane melts due to the instability of diphenylmethane bonds upon heating and melting. Due to its strong tendency to thermal decomposition and gelation during heating, it is completely unsuitable as a melt molding material for extrusion and injection molding purposes. This property of unsuitability for melt molding can hardly be improved by copolymerizing other diamine components. Polyamideimide, which is made up of three components: trimellitic acid anhydride, isophthalic acid dichloride, and ivy phenylene diamine, has practical heat resistance properties, but it has a high melt viscosity when melted by heating, so it cannot be melt-molded. It's not easy.

In addition, boria ε1!, which is synthesized from the general formula synthesized from anhydrous l.limellitic acid dichloride/isophthalic acid dichloride/4,4'-diaminodiphenylsulfone! Since imide has essentially low polymerization activity of 4,4'-cyamyl phenyl sulfo/,
Only a polymer with a low degree of polymerization can be obtained, which is unsatisfactory as a resin for molded articles having practical strength.

In addition, a polyamideimide represented by the general formula (%) synthesized from I.limellitic anhydride dichloride/isophthalic acid dichloride/4.4'-reaminodiphenyl ether (or 4.4'-cyamylphenyl sulfide) Although it has excellent heat resistance, it is difficult to melt and mold it smoothly because the flow start temperature and the thermal decomposition temperature are close to each other.

Therefore, the present inventors developed an aromatic polyamide that has good melt moldability by combining good thermal stability and fluidity in the temperature range of 500 to 4 (10°C), and has an excellent balance of physical properties in the molded product. As a result of extensive research aimed at obtaining an imide, it was discovered that a new thermoplastic aromatic polyamide-imide copolymer having the desired properties could be obtained by combining four specific components. We have arrived at the present invention.

AO＼ The present invention has the formula NH-CO-Z,...-N
+ structural unit, B, formula (Nl-i-CO-O-Co
-Nl-1-) structural unit, C1 formula, 6Q-so2-Q
It consists of a structural unit of + and a structural unit of formula fQ-x-Q+, and the ratio of each structural unit is (C + D) is 1 mole to (A + B) 1 mole, and A/B is 4 ~70 mol%/96-60 mol% and C70 is 10-70 mol%/
The present invention provides a novel thermoplastic polyamide-imide copolymer characterized in that the polyamide-imide content is 90 to 30 mol%.

(However, in the above formula, Z is a hexafunctional aromatic group in which two of the functional groups are bonded to adjacent carbon atoms, and X represents an -8- group or a 10-group. ) The thermoplastic polyamide-imide copolymer of the present invention is mainly composed of four units represented by A, B, C and D above.

Here, the acid component (A + B) and the cyan component (C + D
) are substantially equimolar ratios, and the ratio of each structural unit is A/
B is 4-70 mol%/96-60 mol%, preferably tL<2
0-60 mol%/80-40 mol%, C70 is 10-7
It is selected from the range of 0 mol%/90 to 70 mol%, preferably 20 to 50 mol%/80 to 50 mol%.

If the amount of A units is 4 mol % or less or 70 mol % or more of the (A+B) units, the melt viscosity of the resulting polyamide-imide copolymer becomes too high, which is inappropriate. still,
If the amount of C units exceeds 70 mol% among (C+D) units, only a polyamide-imide copolymer with essentially a low degree of polymerization will be obtained; If the amount decreases, the flow start temperature and thermal decomposition temperature of the polyamide-imide copolymer become too close to each other, making it unsuitable as a melt molding material, which is not preferable.

In addition, Z in the above A unit is a pentafunctional aromatic group in which two of the O functional groups are bonded to adjacent carbons,
For example, the scope of the present invention also includes cases where the imide bond in the A unit is present in an amount of 50 mol % or less, preferably 60 mol % or less, if the imide bond is closed.

The polyamide-imide copolymer of the present invention can be produced using any of the many general production methods that have been proposed to date, but the following two are representative examples with high practicality. Here are some methods.

(1) Incyanate method: A method in which a mixture of aromatic tricarboxylic anhydride and aromatic dicarboxylic acid is reacted with an aromatic diisocyanate (for example, Japanese Patent Publication No. 51-6).
770, etc.).

(2) Acid chloride method: A method in which a mixture of aromatic tricarboxylic acid anhydride chloride and aromatic dicarboxylic acid dichloride is reacted with an aromatic diamine (for example,
(Japanese Patent Publication No. 16,908, Japanese Patent Publication No. 12,594, 1983, etc.).

Among the above two methods, the acid chloride method has the advantage that raw materials are relatively easy to procure, and that it is easy to obtain a highly polymerized polyamide-imide with excellent linearity (less branched structure) through low-temperature solution polymerization. This is the most recommended manufacturing method. Here, the acid chloride method will be explained in more detail as follows. That is, aromatic tricarboxylic anhydride monochloride/inphthalic acid dichloride (
4-70796-60 mole ratio) mixture 1 mol and aromatic diamine ('I) H2N Q 802 Q NH2 10-70 mol% and aromatic diamine (n) 112N-Q-0-Q-NI12 tau02N-Q
-5-Q-NII2 90-50 mol% mixed diamine 0.9-1.
After dissolving 1 mol of hydrogen chloride in an organic polar solvent and mixing for about 05 to 1 hour at a temperature of -20 to 80°C, about 2 to 4 mol of hydrogen chloride scavenger is added to accelerate the polymerization reaction rate. The polymerization reaction is completed at around room temperature and in a reaction time of 0.5 to 10 hours. The polymer produced in this step has a structure in which most (for example, 50 to 100%) of the A units of the polyamide-imide copolymer of the present invention are converted into amide amic acid units of the ring-closing precursor, so-called polyamide amino acids. ing. It is also possible to stagger the addition times of aromatic tricarboxylic acid anhydride chloride and isophthalic acid chloride, in which case the QJ-1 produced polymer becomes a block copolymer1, and the organic The polar solvent is
N such as dimethylacetamide, dimethylpolamide, etc.
・N-dialkylcarboxylic acid amides, N-methylpyrrolidone, helicyclic compounds such as tetrahydrothiophene-1-dioxide, and phenols such as cresol and xylenol, especially N-methylbi-lidone. and N-N-dimethylacetamide are preferred.

Hydrogen chloride scavengers added in the first step are: - aliphatic quaternary amines such as trimethylamine, triethylamine, tripropylamine, tributylamine; cyclic amines such as pyridine, lutidine, collidine, quinoline; Organic bases, alkali metal hydroxides, alkali metal carbonates, alkali metal acetates, alkaline earth metal oxides, alkaline earth metal hydroxides, alkaline earth metal carbonates,
These include inorganic bases such as alkali metal acetates, organic oxide compounds such as ethylene oxide, propylene oxide, etc.

The polyamide amic acid obtained in the first two steps is then subjected to a second dehydration ring closure step and converted into the polyamide imide copolymer of the present invention.

The dehydration ring closure operation is carried out either by liquid phase ring closure in a solution or by in-phase thermal closure by heating in a solid state. There are two types of liquid phase ring closure: a liquid phase chemical ring closure method using a chemical dehydrating agent and a simple liquid phase thermal ring closure method9. The chemical ring closure method uses acetic anhydride,
Aliphatic anhydrides such as propionic anhydride, POC imperial 3,
SOC. , e2, molecular sheets, silica gel, P2O3, A. , e203, etc., at a temperature of 0 to 120°C (preferably 10 to 60°C). In addition, the liquid phase thermal closed term method is
This is carried out by heating the polyamide/amic acid solution to 50 to 400°C (preferably 100 to 250°C). In this case, azeotropic solvents useful for water removal, such as benzene, toluene, quinolene, chlorobenzene, etc.
: More effective when used together. The solid phase thermal closure step is carried out by first isolating the entire polyamide/amic acid polymer from the polyamide/amic acid solution obtained in the first step, and then heat-treating it in a solid state. As a precipitant for isolating the polyamide Φamic acid polymer, a liquid that is miscible with the reaction mixture solvent but in which the polyamide/amic acid itself is insoluble, such as water, methanol, etc., is employed. Heat treatment is usually 150-350℃, 0.5-50℃
It is selected to ensure the desired ring closure rate and melting fluidity based on time conditions.

If the treatment is carried out in the 250 to 350° C. range for too long, the polymer itself tends to form six-dimensional crosslinks, which significantly reduces the fluidity during melting, so care must be taken.

Although the polyamide-imide copolymer targeted by the present invention can be obtained by the production method detailed above, other copolymers other than the components constituting the A unit, B unit, C unit, and D unit are further added to the reaction system. It is possible to copolymerize by using them together within a quantitative range that does not significantly reduce the melt processability and physical properties of the polyamideimide forming the component, and it is within the scope of the present invention.

The aromatic polyamide-imide copolymer of the present invention has a structure in which the imide units are partially ring-opened amic acid bonds, but most have a ring-closed structure, and N-
In methylpyrrolidone solvent, polymer concentration 0.5% by weight, 3
The value of logarithmic viscosity (η〕h) measured at 0℃ is 0.2
It is a high polymerization degree polymer with a polymerization degree of 0 or more, preferably 0.25 or more, and can be used for various purposes as described below.

Compression molding is carried out after tri-blending the polyamide-imide copolymer powder of the present invention with different polymers, additives, fillers, reinforcing agents, etc. as necessary, and then processing the mixture at a temperature of usually 600 to 400°C and a pressure of 500°C.
It is carried out under conditions of 0 to 500 Kg/ctI. In addition, extrusion molding and injection molding may be performed by adding different polymers, additives, fillers,
The process is carried out by supplying a tri-blend of reinforcing agents, etc., or pelletizing it by extruding it into an extrusion molding machine or an injection molding machine, at a temperature of 300 to 400°C.

In particular, the aromatic polyamide-imide copolymer of the present invention has a
It has an extremely good balance of thermal stability and flow properties in the range of ~400°C, making it useful for extrusion molding and injection molding.

In addition, by further subjecting the molded product obtained by heating and melt-molding the polyamide-imide copolymer of the present invention to heat treatment under high-temperature conditions, the molded product has further improved physical properties such as heat distortion temperature, tensile strength, bending strength, and friction and wear characteristics. can be obtained. Such heat treatment conditions include heating the molded product at a temperature of 200°C or higher and below the glass transition temperature of the molded product, particularly 220°C or higher and below (glass transition temperature -5°C) of the molded product for 5 hours. It is appropriate to heat it for more than an hour. If the heat treatment temperature exceeds the glass transition temperature of the molded article, the molded article is undesirably deformed during the heat treatment and has a strong tendency to impair its practicality. Although there are no particular restrictions on the equipment for performing this heat treatment, an ordinary electrically heated oven can suffice to achieve the purpose.

For film and fiber manufacturing applications, polymerization termination solutions can be applied in dry or wet-dry casting processes;
Furthermore, the isolated polymer can be melt-molded by adding suitable additives as necessary. The laminate is made by impregnating a cloth or cloak made of glass fiber, carbon fiber, asbestos fiber, etc. with a polymer solution, and then precuring it by drying/heating to obtain a prepreg.
Manufactured by pressing at 0°C, 50~00Kg/cntt7).

For paint applications, after adding and mixing different types of solvents to the polymerized solution as necessary, the concentration can be adjusted and the resultant solution can be used for practical use.

Hereinafter, the present invention will be explained in further detail using all Examples and Comparative Examples. Note that the value of logarithmic viscosity, which is a guideline for the molecular weight of a polymer, is determined when the polymer concentration is 0 in N-methyl-2-pyrrolidone solvent.
．． 5%, measured at a temperature of 30°C. The melt viscosity of the polymer was determined using □■ Shimadzu's "Koka-type Flow Tester" and all three test pieces were dried to an absolutely dry state in advance.
After being placed in a syringe heated to 60°C and staying there for 8 minutes,
Apply a load of 50 mm to the nozzle in the center of the die (diameter Q,
It was measured by extrusion method from 5 mi, length 1 mm). Also,
The glass transition temperature was measured using a PerkinElmer 1B DSC.
Measured using a device.

Note that measurements of various physical properties were performed according to the following methods.

Bending strength (FS)・・・・・・・・・ASTM
D790 Heat distortion temperature (HD T )・・・・・・AS
'['MD64B-56 (18,56K9/cnt
) Examples 1 to 3 and Comparative Examples 1 to 3 Internal volume 5 equipped with stirrer, thermometer and nitrogen gas inlet tube
4. 4'-diaminodiphenyl sulfone (D DS) and 4,4'-diaminodiphenyl ether (T) DE) 1 After preparing the composition shown in Table 1, anhydrous N-N-dimethyl Acetamide 300
0 and stirred to obtain a homogeneous solution. This mixture was cooled to -10°C in a dry ice/acetone bath.
(Chloroformyl) phthalic anhydride (TMAC) 101.
1. P (0.48 mol) and isophthalic acid dichloride 146.2y-(IPC) (0.72 mol) were added in small portions at a rate that maintained the temperature of the polymerization system at -10 to -5°C. . After continuing stirring at 0°C for an additional hour, 214,P (2.1 mol) of anhydrous triethylamine was added in portions at a rate sufficient to maintain the total temperature of the polymerization system at about 5°C or less. Next, after stirring for 52 hours, pyridine 1
50- and 300 m/(approx. 6.2 mol) of acetic anhydride were added and stirred overnight at room temperature.

Next, the polymerization finished liquid was gradually poured into water under high-speed stirring to precipitate the polymer into powder, which was thoroughly washed with water/dehydrated, and then heated in a hot air dryer at 150°C for 5 hours, followed by 200°C. ℃
After drying for 6 hours, the logarithmic viscosity (η1nh) and melt viscosity (μa
) and a glass transition temperature (Tg) was obtained. This Example 1~Rono η1o1. was sufficiently high compared to Comparative Examples 2 and 6. Also, Comparative Example 1
The polymer did not melt at all under the conditions of 660°C.

The theoretical structural formula and molecular formula of the copolymer obtained in Example 1 are as follows, and the elemental analysis results of the copolymer are shown in Table 2, showing good agreement with the theoretical values. .

/(-Q-8O='Q-1-n/(-Q-0-Q'l-
8-4; C9H4N2O3+, ti/+ CgH
a N2O2h,. /+ Cl2H802S )n/+
Cl2I]80+.

Swamp / m / n / o = 0.48 / 0.7
2 / 0.24 / 0.96 (molar ratio) = 40 /
60/20/80 (molar ratio) Elemental analysis was also conducted on the polymers of Examples 2 and 30, and the results showed good agreement with the theoretical values.

(19) Next, the obtained copolymer powder was added with tetrafluoroethylene resin as an anti-oxidation agent (Asahi Glass Company, Aflon Polymist F-
After adding 5.2% by weight, the mixture was fed to a Prabender Plastograph extruder (processing temperature 340-660°C) to obtain melt-extruded pellets. Next, the obtained pellets are compression molded (processing temperature 530-360℃, pressure 50-360℃,
100 to 9/cd) to create a test piece, put the formed test piece in a hot air dryer and dry it at 150°C for a day and night.
24 hours at 20°C, 24 hours at 245°C, followed by 260°C.
Heat treatment was performed at ℃ for 24 hours. Subsequently, physical properties were measured, and the results shown in the column of properties of molded product after heat treatment in Table 1 were obtained.

However, the polymer obtained in Comparative Example 1 did not melt at 660°C, and a sufficiently molten molded product could not be obtained under the above compression molding conditions.

Further, in relation to the small ηinh of Comparative Examples 2 and 30 polymers, the bending strength of the molded products was extremely low even after heat treatment.

(20) Table 2 Elemental analysis results Example 4 TMAC75, Bf (0.36 mol) and I P CI 70.57 (0.84 mol) as acid components, D D 874.5 f (0, 3 mol) and DDEl 80.27 (0.9 mol), propylene oxide t 21. as deoxidizer. s y (2
, 1 mole) was carried out in the same manner as in the first half of Example 1 to obtain a polymer powder with η1nh=0.48 and μa-2×103 m2×103 Boise°C.

This polymer has the same theoretical structural formula as in Example 1 (with the exception of 1.
8/”/n/o = o, 36/0.8
410, 3/0.9 molar ratio = 30/70/25/7
5 molar ratio), and the elemental analysis results also agreed well with this theoretical value.

Next, using the obtained polymer, 2% by weight of tetrafluoroethylene resin and 3% of short glass fibers were prepared in the same manner as in the latter half of Example 1.
After blending 0% by weight, compression molding was performed to obtain a molded test piece,
Subsequently, heat treatment was performed under the same conditions as in Example 1, resulting in Tg=281°C, HDT=275°C, FS=2. s
o.

A molded article with excellent physical properties of Kg/crA was obtained.

Example 5 TMAC126,3 (0,6 mol) and IP CI 21,8 y (0,6 mol) as acid components, DDS a 9,4 y (0,3 mol) as diamine components
6 mol) and 4,4'-diaminodiphenylsulfide 181,6 (0.84 mol) and N-methylmorpholine 192p (1,9 mol) as a deoxidizing agent. and ηi, h=0
．． 33, μa-19×10 3 me 19×10 3 poise polymer powder was obtained.

This polymer has the following theoretical structural formula, and the results of elemental analysis also showed good agreement with this theoretical value.

/(Q 802 Q几/[C>-8-Q-)Q-e/
m / n / o = 0.6 / 0° + 1510
．． ! + 670.84 (molar ratio) = 50150/30
/70 (mole ratio) Next, using the obtained polymer, 2% by weight of tetrafluoroethylene resin was blended in the same manner as in the latter half of Example 1, and then compression molded to obtain a molded test piece. When heat treatment was performed under the same conditions as in Example 1, T
g=286℃, HDT=275℃, 1i'S=6
A molded article with excellent physical properties of 50 Kg/crl was obtained.

Claims (1)

[Claims] O Raras, the ratio of each structural unit is 1 mol of (C-1-D) to 1 mol of (A-1-B), and A/B is 4
~70 mol%/96-30 mol%, C/D 10-7
A thermoplastic polyamide-imide copolymer characterized in that the content is 0 mol%/90-30 mol%. (However, Z in the above formula is a functional aromatic group in which two of the three functional groups are bonded to adjacent carbon atoms, and represents an X-S- group or a -0- group. )