JPH04496B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing polyamide-imide resin that has excellent heat resistance, melt flowability, mechanical strength, and economic efficiency. (Prior Art) Conventionally, as a thermoplastic polyamide-imide resin that can be injection molded, The product name ``Torlon'' manufactured by Amoco is well known. Although it has excellent heat resistance (thermal softening temperature: approximately 285°C), it has limitations in use, such as poor melt flowability and the need for a special molding machine. There is a polyetherimide for injection molding with significantly improved melt flowability under the trade name ``Ultem'' manufactured by General Electric Company, but it has insufficient heat resistance (thermal softening temperature: approximately 210°C) and Cannot be used in applications that require heat-resistant solderability at temperatures around ℃. Therefore, the heat resistance is close to that of Torlon, and the melt fluidity is similar to that of Ultem.
There is a long-awaited need for a thermoplastic molding material similar to As a thermoplastic polyamide-imide resin aiming at the above-mentioned well-balanced heat resistance and melt fluidity, Japanese Patent Laid-Open Nos. 1983-129421 and 1982-112933 disclose
No. 79019, JP 58-79019, JP 58-
Publication No. 79020, Japanese Patent Application Laid-Open No. 1982-91723, Japanese Patent Application Publication No. 1983
This method has been proposed in JP-A-91724, Japanese Patent Laid-Open No. 58-91727, etc. However, these are extremely disadvantageous in terms of economy because they use expensive diaminodiphenyl ether, polyether diamine, or diaminodiphenylsulfone as the main constituent material of the polyamide-imide resin, and are therefore not suitable for general purpose use. It is unsuitable for Many methods for producing inexpensive polyamide-imide resins have been known for a long time, unless they are specifically limited to thermoplastic resins. The following two methods are known as typical methods for manufacturing inexpensive polyamide-imide resins. (1) Isocyanate method: A method of reacting trimellitic anhydride with diphenylmethane-4,4'-diisocyanate (for example,
Publication No. 19274, Japanese Patent Publication No. 54-44719, Japanese Patent Publication No. 1987-44719
50-70452, JP-A-57-125220). (2) Amine method: trimellitic anhydride and 4,4'-
A method of reacting diaminodiphenylmethane (for example, Japanese Patent Publication No. 49-4077, Japanese Unexamined Patent Application Publication No. 1988-57)
-14622, Japanese Patent Application Laid-open No. 104596/1983). As a result of examining the polyamide-imide resins obtained by methods (1) and (2) above as thermoplastic molding materials, it was found that both have sufficient heat resistance and economic efficiency because they are obtained as general-purpose aromatic two-component systems. It was found that only a very low level of melt fluidity could be obtained. In addition, trimellitic acid chloride and 4,4'-
The acid chloride method, which involves reacting with diaminodiphenylmethane, is uneconomical in that it has insufficient melt fluidity and requires an extremely uneconomical process to remove and purify by-product hydrogen chloride (for example,
(Japanese Patent Publication No. 42-15637, Japanese Patent Application Laid-open No. 182323/1983). In addition to the two components of trimellitic anhydride or its derivative and 4,4'-diaminodiphenylmethane in the amine method of (2), the present inventors added specific amounts of the two components of isophthalic acid and lactam to Surprisingly, by combining isophthalic acid and lactam in the same proportions, it is possible to obtain a high degree of melt fluidity that cannot be obtained by modifying each component individually.As a result, the heat resistance and melt fluidity described above are obtained. It was discovered that a thermoplastic polyamide-imide resin with an excellent balance of mechanical strength and economical efficiency can be obtained. Isophthalic acid and lactam are industrially inexpensive materials and pose no economic disadvantage. It is known that a single component of lactam is used in combination with the polyamide-imide resin obtained by the isocyanate method (1) (for example, Japanese Patent Publication No. 46-29730, Japanese Patent Publication No. 56-34209, Japanese Patent Publication No. 58-18926). (Japanese Patent Application Laid-open No. 56-41218). Furthermore, it is already known that the two components of isophthalic acid and lactam are used in combination with the polyamideimide resin obtained by the isocyanate method (1) (for example, Japanese Patent Publication No. 53-47157, Japanese Patent Application Laid-open No. 50-25698). Publication, JP-A-53-106795, JP-A-58-
208323, Japanese Patent Application Laid-Open No. 1983-80326). However, the polyamide-imide resin obtained by the isocyanate method (1) is obtained by a solution polymerization method, and the synthesis solvent used is an acidic solvent such as cresol or a basic solvent such as N-methylpyrrolidone. When an acidic solvent is used, a high molecular weight polyamideimide resin cannot be produced, resulting in poor heat resistance and mechanical properties. Furthermore, when a basic solvent is used, undesirable side reactions occur, resulting in a disadvantage that melt fluidity is significantly impaired. It is known that a single component of isophthalic acid is used in combination with the polyamide-imide resin obtained by the amine method (2) (Japanese Patent Publication No. 49-4077, JP-A-57-
14622). In the amine method (2), side reactions are relatively unlikely to occur and it is possible to develop excellent melt fluidity. (especially melt fluidity) cannot be obtained. It is also known to use the two components of isophthalic acid and a specific amount of lactam together in the amine method (2) (Japanese Patent Publication No. 17374/1982). However, since the amount of lactam used is too large, there is a problem in that only a polymer with a low heat softening temperature can be obtained. (Object of the invention) The object of the present invention is to provide a method for producing a polyamide-imide resin that does not have the above-mentioned drawbacks and has an excellent balance of heat resistance (thermal softening temperature), melt fluidity, mechanical strength, and economic efficiency. It is something. (Structure of the Invention) The present invention provides the following steps: () trimellitic anhydride or its derivative () 4,4'-diaminodiphenylmethane () isophthalic acid () lactam in a polar solvent in the presence of a dehydration catalyst, () ()/()+()=0.03~0.25 (molar ratio), (
) is reacted with () / () + () = 0.08 to 0.25 (molar ratio) and () + () in a ratio of almost equimolar ratio of () to polyamideimide with a reduced viscosity of 0.40 or more. Concerning a method for producing resin. As the derivative of trimellitic anhydride in the present invention, trimellitic acid, an esterified product of trimellitic acid anhydride and alcohol, for example, a methanol half ester of trimellitic acid anhydride, etc. are used. As trimellitic anhydride or its derivative, trimellitic anhydride is preferably used. The lactam in the present invention has the general formula (In the formula, n represents an integer from 2 to 20.) A lactam is used. Preferably, ε-caprolactam is used. The polar solvent used in the present invention is one that can dissolve the polyamideimide resin produced well and has a boiling point of 180°C.
Those mentioned above are preferably used. For example, N-methylpyrrolidone, N-ethylpyrrolidone, N-butylpyrrolidone, phenol, cresol, xylenol, sulfolane, etc. are used. N-methylpyrrolidone is preferably used. As the dehydration catalyst in the present invention, for example, trivalent or pentavalent organic or inorganic phosphorus compounds, lead monoxide, boric acid, boric anhydride, etc. are used. Phosphoric acid, triphenyl phosphate, boric acid, and boric anhydride are preferably used. Isophthalic acid () is ()/()+()=0.03
~0.25 (molar ratio) (() is trimellitic anhydride or its derivative).
If it is less than 0.03, melt fluidity will decrease, and if it exceeds 0.25, heat resistance will decrease. Lactam () is ()/()+()=0.08~0.
It is used at a ratio of 25 (molar ratio). If it is less than 0.08, melt fluidity will decrease, and if it exceeds 0.25, heat resistance will decrease significantly. In particular, when considering the balance between heat resistance and melt fluidity, () is () / () + () = 0.
08 to 0.15 (molar ratio), () to ()/() + () = 0.
It is preferable to use it in a ratio of 10 to 0.18 (molar ratio). The ratio of the acid component (()+()) and the amine component () is such that the ratio of () to ()+() is approximately equimolar. In particular, ()/()+()
= 1.02 to 0.98 (molar ratio). The dehydration catalyst is preferably used in an amount of 0.1 to 10% by weight, particularly 1 to 5% by weight based on ()+(). It is preferable to proceed with the polymerization while distilling off by-product water from the reaction system. The polymerization concentration may be about 40 to 50% by weight at the early stage of the reaction, and is preferably increased to around 65% by weight at the latter stage of the reaction in order to maintain a high temperature. Polymerization is carried out by imidization in the first stage and polymerization in the second stage. It is preferable to carry out the reaction at a temperature around 205 to 210°C. Reduced viscosity of polyamideimide resin produced according to the present invention (dimethylformamide, 0.5g/
dl, 30℃) is considered to be 0.40 or higher. If it is less than 0.40, mechanical strength will be poor. The terminal groups of the polyamideimide resin produced according to the present invention can be blocked with an end group blocking agent after the polymerization reaction is completed. As such a terminal group blocking agent, phthalic anhydride, benzoic acid, acetic anhydride, aniline, n-butylamine, phenyl isocyanate, etc. are used. By capping the terminal groups, thermal stability during molding is improved. The polyamide-imide resin obtained by the production method of the present invention is prepared by adding the above-mentioned polar solvents or low-boiling general organic solvents such as chloroform, tetrahydrofuran, dioxane, toluene, xylene, etc. to the solution after polymerization, if necessary. Additionally, it is diluted. The polyamideimide resin obtained by the production method of the present invention can be used in the form of a solution or powder. In addition, if necessary, different polymers,
Additives, fillers, reinforcing agents, etc. can be blended. The physical properties of the polyamide-imide resin of the present invention can be significantly improved by subjecting it to heat treatment (at 200 to 300°C for 1 to 24 hours) after molding, if necessary. The polyamide-imide resin obtained by the production method of the present invention is mainly suitable for use as a thermoplastic molding material, but it is of course possible to use it for other uses. For example, heat-resistant paint, heat-resistant sheets,
It is useful for heat-resistant adhesives, heat-resistant laminated materials, heat-resistant sliding materials, heat-resistant fibers, heat-resistant films, etc. (Effect of the invention) According to the present invention, a polyamide-imide resin having an excellent balance of heat resistance, melt fluidity, mechanical strength, and economical efficiency can be obtained. (Example) The present invention will be described in Example 1 and This will be explained using a comparative example. Example 1

【table】

[Table] The above ingredients are measured using a thermometer, stirrer, nitrogen inlet pipe,
The mixture was placed in a four-necked flask equipped with a moisture meter, and heated to 160°C while passing nitrogen gas. The temperature was gradually raised to 175° C. in 4 hours while distilled water was removed from the system. then
The temperature was raised to 205°C, and the reaction proceeded in the temperature range of 205-210°C. The end point of the reaction was controlled by Gardner viscosity, and the reduced viscosity (dimethylformamide, 0.5/dl, 30℃,
The same applies hereafter) A polyamideimide resin of 0.41 was obtained.
The obtained polyamide-imide resin solution was diluted with N-methylpyrrolidone to about 25% by weight, and this solution was poured into water that was vigorously stirred with a mixer to recover a solid polyamide-imide resin.
After thoroughly washing this solid resin with hot water, it was boiled and washed with a large amount of water. After taking this, it was dried in a hot air dryer at 130°C for 6 hours to obtain a powdered polyamide-imide resin. Example 2

[Table] A powder polyamide-imide resin having a reduced viscosity of 0.43 was obtained by using the same equipment and operation as in Example 1 except that the above components were used. Example 3

[Table] A powder polyamide-imide resin having a reduced viscosity of 0.49 was obtained by using the same equipment and operation as in Example 1 except that the above components were used. Example 4

[Table] A powdered polyamide-imide resin having a reduced viscosity of 0.41 was obtained by using the same equipment and operation as in Example 1 except for using the above components. Example 5

[Table] A powder polyamide-imide resin having a reduced viscosity of 0.45 was obtained by using the same equipment and operation as in Example 1 except that the above components were used. Example 6

[Table] A powder polyamide-imide resin having a reduced viscosity of 0.43 was obtained by using the same equipment and operation as in Example 1 except that the above components were used. Example 7

【table】

[Table] A powder polyamide-imide resin having a reduced viscosity of 0.53 was obtained by using the same equipment and operation as in Example 1 except that the above components were used. Comparative example 1

[Table] A powder polyamide-imide resin having a reduced viscosity of 0.50 was obtained by using the same equipment and operation as in Example 1 except that the above components were used. Comparative example 2

[Table] A powder polyamide-imide resin having a reduced viscosity of 0.47 was obtained by using the same equipment and operation as in Example 1 except that the above components were used. Comparative example 3

[Table] A powder polyamide-imide resin having a reduced viscosity of 0.53 was obtained by using the same equipment and operation as in Example 1 except that the above components were used. Comparative example 4

【table】

[Table] A powdered polyamide-imide resin having a reduced viscosity of 0.47 was obtained by using the same equipment and operation as in Example 1 except that the above components were used. Comparative example 5

[Table] A powder polyamide-imide resin having a reduced viscosity of 0.43 was obtained by using the same equipment and operation as in Example 1 except that the above components were used. Comparative example 6

[Table] A powdered polyamide-imide resin having a reduced viscosity of 0.35 was obtained by using the same equipment and operation as in Example 1 except for using the above components. Comparative example 7

[Table] A powdered polyamide-imide resin having a reduced viscosity of 0.35 was obtained by using the same equipment and operation as in Example 1 except for using the above components. Comparative example 8

[Table] A powder polyamide-imide resin having a reduced viscosity of 0.48 was obtained by using the same equipment and operation as in Example 1 except that the above components were used. Comparative example 9

[Table] Add the above ingredients to a four-necked flask equipped with a thermometer, stirrer, and nitrogen inlet tube while stirring.
The temperature was raised to 100°C while passing nitrogen gas, and the reaction was continued at this temperature for 1 hour, then at 125°C for 2 hours, at 140°C for 2 hours, and further at 175°C for 4 hours. The obtained polyamide-imide resin solution was subjected to exactly the same operation as in Example 1 to obtain a powdered polyamide-imide resin having a reduced viscosity of 0.35. Comparative example 10

[Table] Add the above ingredients to a four-necked flask equipped with a thermometer, stirrer, and nitrogen inlet tube while stirring.
Heat to 150℃ while passing nitrogen gas, then at this temperature for 2 hours, then at 170℃ for 2 hours, and then at 200℃.
The reaction proceeded for 12 hours. The obtained polyamide-imide resin solution was diluted with cresol to a concentration of about 25% by weight, and this solution was poured into methanol that had been vigorously stirred with a mixer to recover a solid polyamide-imide resin. This solid resin was boiled and washed with a large amount of methanol. After this was taken, it was dried at 80° C. for 6 hours under reduced pressure to obtain a powdered polyamideimide resin with a reduced viscosity of 0.12. Comparative Example 11 Heat resistance (thermal softening temperature) of Amoco's product name "Torlon" 4000T (powdered polyamide-imide resin)
The melt fluidity was evaluated and the results are shown in Table 2. Comparative Example 12 The heat resistance (thermal softening temperature) and melt fluidity of "Ultem" 1000 (a pellet-like polyetherimide resin) manufactured by General Electric Company were evaluated, and the results are shown in Table 2. The heat resistance (thermal softening temperature), melt fluidity, and mechanical strength of the polyamide-imide resins of Examples 1 to 7 and Comparative Examples 1 to 12 were evaluated. The results are shown in Tables 1, 2 and 3. Thermal softening temperature is determined by PerkinElmer's "TMS-
Measurement was carried out using a "Model 1" thermophysical testing machine with a load of 100 g·f and the penetration method. Melt fluidity was measured using a "Koka Type Flow Tester, CFT-500" manufactured by Shimadzu Corporation. After putting 1.5g of a sufficiently dried sample into a cylinder heated to 300℃ and allowing it to distill for 3 minutes, it was passed through the center nozzle of the die (diameter 1.0mm, length 2mm) with a load of 300Kg・f.
It was measured by extrusion method. Mechanical strength (Izotsu impact value) was measured using an Izotsu impact tester (manufactured by Toyo Seiki) using a hammer load.
Measured at 2.742Kg・f and launch angle of 150°. The sample is 2.5
An extruded rod of mmφ was used.

【table】

【table】

[Table] From Tables 1, 2, and 3, the polyamide-imide resins of Examples 1 to 7 have heat resistance and melt fluidity that are intermediate between those of "Ultem" and "Torlon."
It is shown that it is particularly well-balanced as a heat-resistant molding material. In addition, by setting the reduced viscosity to 0.4 or more,
It is shown to have excellent mechanical strength, with an Izot impact value of 0.5 or higher. Furthermore, since the polyamideimide resin obtained by the production method of the present invention is made of a general-purpose and inexpensive material, it is also highly economical.

Claims (1)

[Scope of Claims] 1 () Trimellitic anhydride or its derivative () 4,4'-diaminodiphenylmethane () Isophthalic acid () Lactam is prepared by treating () in a polar solvent in the presence of a dehydration catalyst. )/()+()=0.03-0.25 (molar ratio), (
) is reacted with () / () + () = 0.08 to 0.25 (molar ratio) and () + () in a ratio of approximately equal moles of () to make the reduced viscosity 0.40 or more. Characteristic manufacturing method of polyamide-imide resin. 2. The method for producing a polyamideimide resin according to claim 1, wherein the lactam is ε-caprolactam. 3. The method for producing a polyamideimide resin according to claim 1 or 2, wherein the polar solvent is N-methylpyrrolidone. 4 () to ()/()+()=1.02-0.98 (molar ratio), () to ()/()+()=0.08-0.15 (molar ratio), () to ()/()+ Claims 1, 2 or 3 used at a ratio of ( ) = 0.10 to 0.18 (molar ratio)
2. Method for producing polyamideimide resin described in Section 1.