JPS6262859A - Polyimide resin composition - Google Patents

Abstract

PURPOSE:The titled composition having not only improved melt processing properties but also improved viscosity stability in melt molding, obtained by blending a thermoplastic polyimide resin with a small amount of an aromatic polycarboxylic acid ester. CONSTITUTION:(A) 100pts.wt. polyimide resin having no polymerizable group at its end groups and side chains, showing substantially a melt state at <=a decomposition temperature, capable of being processed in a molten state, having preferably 150-300 deg.C glass transition temperature, such as polyimide resin shown by the formula (Ar<1> is tetrafunctional aromatic residue as a tetracarboxylic acid residue wherein two carbonyl groups are bonded to neighboring carbon atoms and other two carbonyl groups are bonded to neighboring carbon atoms; Ar<2> is bifunctional aromatic group as diamine residue) is blended with (B) >=0.002pt.wt., preferably 0.005-0.5pt.wt. aromatic polycarboxylic acid ester such as tributyl trimellitate, tatrabutyl pyromellitate, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thermoplastic polyimide resin composition having improved viscosity stability during melt molding.

Conventional technology Non-thermoplastic polyimide resins, such as polyimide obtained by the reaction of pyromellitic anhydride and diaminodiphenyl ether, are widely known to have excellent heat resistance and durability and are used industrially. . However, these polyimide resins have poor processability,
It is extremely difficult to mold parts into complex shapes. Therefore, while maintaining the excellent properties of polyimide resin as much as possible,
There is a strong demand for the development of thermoplastic polyimide resins that can be processed by melt molding means. In order to meet these industrial needs, several types of thermoplastic polyimide resins have been developed in recent years, for example, in JP-A-49-103997 and JP-A-5.
Proposals have been made, as typified by publications such as 9-136327 and JP-A-59-170122.

Problems to be Solved by the Invention Conventionally proposed thermoplastic polyimide resins have poor viscosity stability and fluidity retention during melting, considering that they are molded into various complex shapes as melt molding materials. etc. were not always sufficient.

For example, when trying to obtain a molded product by injection molding or a film by extrusion molding, the viscosity of the resin increases in the molding machine, making it impossible to continuously and stably obtain molded products. The problem was that there wasn't. Moreover, this phenomenon becomes more pronounced as the molding temperature increases, and as the heat resistance of thermoplastic polyimide resin increases, molding processing at high temperatures becomes necessary.Therefore, stabilizing the melt viscosity is an important issue. An early resolution is desired.

On the other hand, it has been speculated that polymer terminal amino groups are involved as a factor in changing the melt viscosity of thermoplastic polyimide resins, and for example, attempts have been made to suppress polymer terminal amine groups by solution reaction during polymer production ( (See Japanese Unexamined Patent Publication No. 170122/1983). However, it is virtually impossible to completely reduce the number of terminal amino groups to zero through such a reaction, and even if a small amount of amino groups remain at the end of the polymer, the viscosity increases, and furthermore, during molding at high temperatures, polyimide resin There is also the problem that trace amounts of water contained therein cause cleavage of imide bonds and generate terminal amine groups.

Means for Solving the Problems The present inventors conducted intensive studies to improve the melt moldability of the above-mentioned thermoplastic polyimide resin, and as a result, they added a small amount of aromatic polycarboxylic acid ester to the thermoplastic polyimide resin. The present invention was achieved by discovering that by doing so, not only the melt processability of thermoplastic polyimide resins is improved, but also the viscosity stability during melt molding is improved.

That is, according to the present invention, at least 0.0% of aromatic polycarboxylic acid ester is added to 100 parts by weight of thermoplastic polyimide.
A stabilized thermoplastic polyimide resin composition containing 0.002 parts by weight is provided.

The thermoplastic polyimide resin that is the first component of the stabilized thermoplastic polyimide resin composition of the present invention does not have polymerizable groups at the terminal or side chain, and is substantially molten at a temperature below the decomposition temperature, and is melt-processable. A typical example thereof is the following formula (I). Furthermore, in consideration of heat resistance and practical molding temperature range, preferred polyimide resins have a glass transition temperature of 150 to 300°C.

[In the formula, Ar1 is a tetravalent aromatic group as a tetracarboxylic acid residue in which two carbonyl groups are attached to adjacent carbon atoms, and Ar2 is a divalent aromatic group as a diamine residue. be. ] As the thermoplastic polyimide resin represented by the above formula (1), for example, the following (If) to (V
), but it goes without saying that these examples do not limit the scope of the present invention.

[In the above formula, Ar3 is -A r'' -0-←◎-3O2
-Q-0-^, j2-0. +.

O-5O2-()-0-Ar” (II 1 ),
@+0-Ar"-0-◎-so, 2-shown, where Ar
represents meta- or paraphenylene, X and y are independently 0.1 or 2, R1 is a direct bond, -o-, -s-, -
5o2-, -co-1 is an alkylene or alkylidene group with 1 to 6 carbon atoms, Ar is an ortho- or meta-phenylene group, l is H3 A, 5ba-R2-◎- or Ar3, and Ar6 is It is the same as A and 32, and Ar7 is an aromatic-grade diamine residue, which is the same as Ar3, Ar31, and Ar32. ]A
A polyimide resin having a structure in which r1 is Maro or H generally exhibits high heat resistance and is preferable as the thermoplastic polyimide resin used in the present invention. In particular, in the polyimide represented by the formula (ff), Ar3 is represented by (II-1) or (n-2), and a polymer in which AR32 does not have an aliphatic group generally has a high glass transition. In addition, it has good heat aging resistance and is the most preferred thermoplastic polyimide resin for use in the present invention.

Aromatic polycarboxylic acid esters which are other essential components of the thermoplastic polyimide resin composition of the present invention include aromatic dicarboxylic acids, tricarboxylic acids, and tetracarboxylic acids having carboxylic acids bonded to at least two adjacent carbon atoms. Examples include acid esters, such as those represented by the following general formulas (VI) to (■).

[In the formula, R3 represents an alkyl group, an aryl group, or a substituted aryl group having 1 to 30 carbon atoms, which is a residue of a monohydric alcohol or a -valent phenol, and from the viewpoint of the degree of reactivity with amines. , preferably an alkyl group having 1 to 10 carbon atoms, and R4 is -R3, -〇R3 or -G-0
-R3, and R5 is a divalent organic group or -o-, -s
-, -5o2-.

-CO-, n is 0.1 or 2, especially (
■) In the formula, nwl or 2, and R4 is -0R
3. -C-0-R3 is preferable because it has a high boiling point and does not cause foaming in the molded product. ] Examples of the above-mentioned aromatic polycarboxylic acid esters include tributyl trimellitate, trioctyl trimellitate, tetrabutyl pyromelli-nodate, tetraoctyl pyromellitate, etc., but these are merely examples. However, the scope of the present invention is not limited in any way.

The thermoplastic polyimide resin composition according to the present invention contains at least 0.002 parts by weight of the aromatic polycarboxylic acid ester, preferably from o, oos to 0.5 parts by weight, based on 100 parts by weight of the thermoplastic polyimide resin. Particularly preferably, the amount is 0.01 to 0.3 parts by weight. That is, if the amount of aromatic polycarboxylic acid ester blended is too small, the desired effect will not be obtained, and on the other hand, if it is too large, the effect will not be particularly high, but foaming may be observed in the molded product. This is not preferable because it may cause deterioration of physical properties.

When producing the thermoplastic polyimide resin composition according to the present invention, the thermoplastic polyimide resin and the aromatic polycarboxylic acid ester can be mixed by any method conventionally used for blending resin compositions. No special device or equipment is required as a mixing device for producing the resin composition of the present invention, and any known device can be used as appropriate. As such an apparatus, for example, a common melt extruder or kneading roll may be used for melt kneading.

Furthermore, the thermoplastic polyimide resin composition according to the present invention includes:
Depending on the purpose, various additives such as weather resistant agents, light resistant agents, heat resistant agents, flame retardants, molding process improvers (e.g. mold release agents and lubricants), and filler reinforcing agents such as glass fibers and inorganic powders are blended as necessary. be able to.

Effects of the Invention The thermoplastic polyimide resin composition according to the present invention described above is characterized in that it not only has a lower melt viscosity and is easier to mold, but also has a stable melt viscosity. The reason why this effect is obtained is not necessarily clear, but it is because the amine remaining at the end of the thermoplastic polyimide or the amine generated during molding reacts with the aromatic polycarboxylic acid ester without producing water as a by-product. This is thought to be because it prevents undesirable side reactions that lead to increased viscosity. However, it goes without saying that this concept does not limit the present invention. Such an effect was not possible with conventional technology.

EXAMPLES Hereinafter, embodiments of the present invention will be explained in detail with reference to Examples, but these Examples are not intended to limit the scope of the present invention in any way.

In addition, in the following Examples and Comparative Examples, the obtained thermoplastic polyimide resin compositions were evaluated as follows.

That is, the polymer resin composition was sufficiently vacuum-dried in advance, and the polymer from which water was removed was heat-treated at a constant temperature and for a constant time. After the heat treatment, the logarithmic viscosity was measured at 30° C. at a concentration of 0.5 g/d1), and the difference from the logarithmic viscosity before the heat treatment was measured.

Δη1nh - ηinh (after heat treatment) - ηinh
(Before heat treatment) Examples 1 to 5 and Comparative Example 1 Thermoplastic polyimide resin (A) was manufactured as follows.

1) Synthesis of oligomer diamine (A) 215. Og (0,749 mol), hydroquinone 61.9 g (0,561 mol), anhydrous potassium carbonate 134.5 g (0,965 mol), triphenylphosphine 1.5 g (0,006 mol) and N
380 g of M P was added. This mixture was allowed to react at about 180° C. for 4 hours with sufficient stirring under a N 2 stream. 41.7% of P-aminephenol was added to the resulting reaction mixture.
g (0,382 mol) followed by a temperature of approx.
The reaction was carried out at 0°C for 7 hours. The obtained reaction product was collected by pouring it into a large amount of water, and then thoroughly washed repeatedly with hot water. It was dried at a temperature of 140° C. for 30 hours to obtain 247 g (yield: 95%) of oligomer diamine (A).

The average molecular weight of this diamine determined by titration method is 1425
(Theoretical molecular weight: 1405). The obtained oligomer diamine (A) had an amino group at the terminal of the following formula.

kNQ -0-+-o-502-o-0-GO valve 0SO
2-o-oQ -N1123.06 2) Polymer synthesis Polymer synthesis was performed using the oligomer diamine obtained above.

2I equipped with stirrer, N2 inlet, thermometer and cooling tower
! The oligomer diamine (A) was added to a Yotsuro flask.
240 g (0,168 mol) and m-cresol 9
60 g was charged and heated to 150° C. under N2 atmosphere to form a homogeneous solution. Add to this 33.6g of pyromellitic anhydride.
(0,154 mol) and 180 moles of toluene were added, and the temperature was raised while stirring thoroughly. An azeotrope of toluene and water was distilled out at an internal temperature of 155 to 160°C, water was separated and collected, and toluene was automatically refluxed into the flask. Under this condition 4
The reaction continued for hours. Thereafter, the reflux of distilled toluene into the flask was stopped, and water and toluene were extracted while gradually raising the temperature. Finally, raise the internal temperature to 180°C,
Most of the toluene was distilled off. The reaction solution was cooled and transferred to another container. Next, 750 methanol was added to the reaction solution while stirring at a temperature of 30° C. or lower to precipitate a polymer. After filtering off the precipitated fine powdery yellow polymer, this polymer was extracted with 750 methanol under stirring for 1 hour. After filtration, the polymer was extracted with fresh methanol twice and then dried. Polymer yield is 260g
(yield 97%), logarithmic viscosity (in NMP) is 0.448
, Tg was 236°C.

The obtained polymer was found to have a terminal amino group and the following repeating unit according to elemental analysis and IR. In addition, thermoplastic polyimide (
A).

O Add a predetermined amount of various aromatic polycarboxylic acid esters to the above polymer (A), pelletize with an extruder at a temperature of about 360 to 370°C, and analyze the aromatic polycarboxylic acid esters in the resulting pellets using a gas chromatograph. After quantification, this was taken as the content. Vacuum drying (180℃/
After sufficiently drying (for 16 hours), a heat treatment test was conducted under certain conditions, and after the test, the logarithmic viscosity was determined, and the change in viscosity before and after the treatment was measured. The measurement results were as shown in Table 1. As is clear from the results in Table 1, aromatic polycarboxylic acid esters were found to have a significant effect on viscosity stability during melting.

Thermoplastic polyimide (B) was produced as follows.

(E) Synthesis of oligomer diamine (B) Oligomer diamine was synthesized using the same recipe as in Examples 1 to 5. The average molecular weight of the obtained oligomer diamine (B) was 1417 (theoretical molecular weight 1405), and it had a structure having an amino group at the terminal as shown below.

Polymer synthesis was performed using this oligomer.

2) Polymer synthesis In a 2N flask equipped with a stirrer, N2 inlet, thermometer, cooling tower, etc., oligomer diamine (B) 240
g (0,169 mol) and m-cresol 960
g was charged and heated to 150° C. under N2 atmosphere to form a homogeneous solution. 34.2 g of pyromellitic anhydride (0,15
7 mol) and 180 g of toluene were added, and the temperature was raised while stirring thoroughly. An azeotrope of toluene and water was distilled out at an internal temperature of 155 to 160°C, water was separated and collected, and toluene was automatically refluxed to the flask. After continuing the reaction under these conditions for 4 hours, 17.7 g (Q. 12 moles) of phthalic anhydride was added to block the excess amine group remaining at the end of the polymer, and the reaction was continued for 1 hour. Thereafter, the reflux of the distilled toluene to the reactor was stopped, and the internal temperature was gradually raised to 180° C. to distill off most of the toluene. The reaction solution was cooled, and polymers were obtained in the same manner as in Examples 1-5. The yield of polymer was 257g (96% yield)
), logarithmic viscosity (in NMP) is 0.470 ST g is 2
The temperature was 38°C.

The obtained polymer was found to be a polymer whose terminal amino groups reacted with phthalic anhydride according to elemental analysis and IR, and was a thermoplastic polyimide (B) having the following repeating unit and capable of melt molding at 300° C. or higher. Further, the amount of terminal amine in the polymer was measured by titration with 1150 ONm of perchloric acid and acetic acid, and it was found that the polymer had 3 x 10 mol of amino groups per gram of polymer.

Various amounts of tri-2-ethylhexyl trimellitate were kneaded by the same method as in Examples 1 to 5, and a heat treatment test was conducted, and the presence or absence of foaming after the heat treatment was observed. The results were as shown in Table 2.

As is clear from the results in Table 2, the addition of the aromatic polycarboxylic acid ester resulted in no foaming and excellent viscosity stability during melting.

Examples 11 to 15 and Comparative Examples 3 to 5 Thermoplastic polyimide (C) was manufactured by the following method.

1) Synthesis of oligomer diamine (C) 2I equipped with a stirrer, N2 inlet, condenser and thermometer! In a Yotsuro flask, 229.7 g (0.8 mol) of 4,4''-dichlorodiphenylsulfone, 130.3 g (0.7 mol) of 4.4''-dihydroxydiphenyl, and 143.74 g (1,04 mol) of anhydrous potassium carbonate were added. mole), triphenylphosphine 1.5 g (0,006
mol) and 430 g of NMP were added. The mixture was reacted at about 180''C for 4 hours under a N2 stream with thorough stirring.

reaction? 22.0g of P-aminophenol (0,
202 mol) was added thereto, and the reaction was subsequently carried out at about f80°C for 7 hours. The reaction product was collected by pouring it into a large amount of water, and then thoroughly washed with hot water repeatedly. 140℃/30
Oligomeric diamine (C) after drying for 310.7 hours
g (yield 96%) was obtained. The average molecular weight of the diamine determined by titration was 3200 (theoretical molecular weight 3236). The obtained oligomer diamine was an oligomer diamine (C) having an amino group at the terminal as shown below.

82 N 4 502-c>O-0'O” 0 +-D
S 02-O-0-Or N H26,91 Polymer synthesis was performed using this oligomer.

2) Polymer Synthesis 224 g (0.07 mol) of oligomer diamine (C), 13.1 g (0.06 mol) of pyromellitic anhydride and 14 phthalic anhydride were prepared in the same manner as in the polymer synthesis of Examples 6 to 10. Polymer (C) was synthesized using .8 g (0.1 mol).

The polymer yield was 229 g (yield 97%), and the logarithmic viscosity (
) in NMP was 0.465, and T g was 239°C.

The obtained polymer was found to be a thermoplastic polyimide (C) having the following repeating unit and melt moldable at 300° C. or higher based on elemental analysis and IR.

Q Tetra-2-ethylhexyl pyromellitate was kneaded in the same manner as in Examples 1 to 5, and heat treatment tests were conducted under various conditions. The results are shown in Table 3. As is clear from Table 3, 2-ethylhexyl pyromellitate is effective in viscosity stability during melting even after various heat treatments.

i) Production of thermoplastic polyimide (D) 4,4'-bis(3,4-dicarboxyphenoxy)biphenyl anhydride as acid anhydride<acid m hydrate (D)) Examples 1 to 5 as diamine component Obtained by a similar method,
Polymer synthesis was performed using oligomer diamine (D) having the following structure.

H2N-0'O(GSO2-GO-00#, C>5O2
-Q-o-Q-N112, i.e., oligomeric diamine (D) 14 in a manner similar to the polymer synthesis of Examples 6-10.
3.2 g (0.1 mol), acid anhydride (D) 47.
4g (0,099 mol), phthalic anhydride 1.5g
Polyimide (D) was synthesized from <0.01 mol).

The yield of polymer was 170 g (91% yield), the logarithmic viscosity (in NMP) was 0.490, and the T g was 223°C.

The obtained polymer was found to be a thermoplastic polyimide (D) having the following repeating unit and melt moldable at 300° C. or higher based on elemental analysis and IR.

ii) Production of thermoplastic polyimide (E) As the acid anhydride, 3,3'-4,4'-biphenyltetracarboxylic dianhydride (acid anhydride (E) as the diamine component Example 1
Polymer synthesis was carried out using an oligomer diamine (E) having the following structure obtained by the same method as in 5.

(H2N-o-o(0”5O2-OO-O0bo-sO
20-GNt12) That is, oligomeric diamine (E) 141 was prepared in the same manner as in the polymer synthesis of Examples 6 to 10.
．． 2 g (0.1 mol), acid anhydride (E) 28.8
g (0,098 mol), phthalic anhydride 3.0 g
Polyimide (E) was synthesized from (0.02 mol).

Polymer yield was 155g (yield 93%), logarithmic viscosity (
(in NMP) was 0.484, and T g was 215°C.

The obtained polymer was determined by elemental analysis to be a thermoplastic polyimide (E) having the following repeating unit from [R] and melt moldable at 300° C. or higher.

iii) As the synthetic acid anhydride for thermoplastic polyimide (F), 2,2-bis(4-(3,4-dicarboxyphenoxy)phenyl)propanide anhydride (acid anhydride (F)
), polymer synthesis was performed using m-phenylenediamine as the diamine component.

That is, in the same manner as the polymer synthesis of Examples 6 to 10,
Polyimide (F) from 27.0 g (0.25 mol) of m-phenylenediamine, 127.5 g (0.245 mol) of acid anhydride (F) and 7.4 g (0.05 mol) of phthalic anhydride was synthesized.

Polymer yield was 136 g (92.5% yield), logarithmic viscosity (in NMP) was 0.471, and T g was 218°C.

The obtained polymer was found to be a thermoplastic polyimide (F) having the following repeating unit and melt moldable at 300° C. or higher based on elemental analysis and IR.

Sauce H3 Three types of thermoplastic polyimides (D) to (F
) was kneaded with 2-ethylhexyl trimellitate in the same manner as in Examples 1 to 5, and a heat treatment test was conducted. The results obtained are shown in Table 4. As is clear from the results in Table 4, polymers containing tri-2-ethylhexyl trimellitate have significantly improved viscosity stability during melting compared to polymers that do not contain tri-2-ethylhexyl trimellitate. It can be seen that this is significant.

Claims (1)

[Claims] 1. A stabilized thermoplastic polyimide resin composition comprising at least 0.002 parts by weight of aromatic polycarboxylic acid ester per 100 parts by weight of thermoplastic polyimide.