JPH03231967A - Polyimide composition - Google Patents

Abstract

PURPOSE:To obtain the title composition with high toughness capable of injection molding by blending a high-toughness prepolymer with another prepolymer of high thermosetting rate each of which has been prepared by reaction between each specific bismaleimide and diamine. CONSTITUTION:The objective composition can be obtained by blending (A) 100 pts.wt. of a prepolymer produced by reaction between A1: a bismaleimide of formula I (A is >=2C divalent organic group) and A2: a diamine of formula II B is <=30C divalent organic group) at the molar ratio A1/A2=1.5-10 (esp. 2-5) with (B) 20-100 (pref. 50-100) pts.wt. of another prepolymer produced by reaction between B1: a bismaleimide of formula III R1 and R2 are each H, methyl, nitro, cyano or halogen) and B2: a diamine of formula) IV[X is of formula V or formula VI (n is integer >=1; Y is O, CH2, CO, etc.)] at the molar ratio B1/B2=1-1.4 (esp. 1.1-1.3).

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention (Industrial Application Field) The present invention relates to a polyimide composition having high toughness and capable of being injection molded.

(Prior art) Some industrial machine parts are used under harsh conditions with high loads, and it is necessary to prevent wear of these parts as much as possible and improve their mechanical strength. It is required to do so.

Polyimide resin is widely used as a material for sliding parts because it has excellent heat resistance.

Such polyimide resin can be turned into a liquid (UL) by heating.
, thermosetting, which exhibits fluidity or softens and exhibits plasticity, and at the same time hardens by creating two-dimensional crosslinks between molecules through a chemical reaction, and has irreversible properties that do not soften even when heated again. It is resin.

Various imide compositions obtained by reacting bismaleimide and cyamine have been developed to improve the curing speed and curing reaction during thermal curing.

(Problems to be Solved by the Invention) Such polyimide resins have various properties that change depending on the components to be reacted, and have completely opposite properties. Sometimes it is done.

Therefore, when performing these moldings, it is necessary to use a molding method suitable for the properties of the polyimide resin.

For example, the imide prepolymer obtained by reacting unsaturated bismaleimide and aromatic diamine described in Jikai 1zl-+q4so publication has a temperature of +00-200°C.
It takes about one hour to melt and harden by heating to around 200°C until it is hard enough to be removed from the mold.

On the other hand, the polybismaleimide prepolymer prepared by reacting bismaleimide and diamine described in Japanese Patent Publication No. 4G-23250, which is different from the above-mentioned imide prepolymer, becomes molten at about 100°C and has a
It hardens in about 2 minutes when heated to °C.

That is, although the polybismaleimide prepolymer has a fast curing reaction and can be used by injection molding with high molding efficiency, there is a problem that the obtained cured product is hard and brittle.

On the other hand, injection molding cannot be applied to imide-based prepolymers because the curing reaction takes time.Compression molding is mainly applied, but the prepolymer itself has high solubility in solvents, and the resulting cured product is It has the characteristic of high toughness.

However, compression molding has poor molding efficiency, tends to cause distortions and cracks depending on the pressurized state, and is difficult to produce molded products with complex shapes. Therefore, polyimide compositions that can be injection molded and have toughness are desired.

In other words, while it has certain excellent properties, it also has problematic properties [2], and the current situation is that sacrifices must be made somewhere.

Therefore, the development of a polyimide composition that compensates for the problematic properties and has both a rapid curing reaction rate and high toughness has become a major issue.

The present invention was made to solve these problems, and one object thereof is to provide a polyimide composition that has both injection moldability, high strength, and high toughness.

[Structure of the Invention] (Means for Solving the Problems) The polyimide composition of the present invention has the following features: (wherein A represents a divalent i-organic group containing at least two carbon atoms r-.) Bismaleimide represented by the general formula: 112N-B-11112...(b)(
In the formula, B represents a divalent organic group containing 30 or more carbon atoms. ) to 100 parts by weight of the prepolymer obtained by reacting with the diamine represented by (B) - Funato: (In the formula, "l, l?2 are hydrogen ha; miko, methyl group, respectively. , does not indicate a nitro group, cyano group, or halogen group.)
Bismaleimide represented by -Sailor: H2N%ox-xoshaNH2...
(d) (in the formula, X is 9) yo, or -ec y%
-1 (TI is an integer greater than or equal to 1, Y is 10--CI
l2C(CIl3)2--C(CF3
)2--8--802 or a divalent group of -CO-. It is characterized by being blended in a range of 20 to 100 parts by weight of a monopolymer obtained by reacting with a diamine represented by ).

Generally, when a brittle resin is mixed with a resin with excellent toughness, the toughness of the blended resin is affected by the brittle resin, and...
! Do not face each other.

[, the light combination of the rudder and the book is 2J- as the (B) component.
The solubility of the zimide prepolymer is excellent, and (A)
It was discovered that the toughness of the blended resin is improved and the moldability is not impaired because the length between the crosslinking points is lengthened by curing after the component and the component (B) are fully compatible with each other, leading to the present invention. Ta.

In the present invention, the prepolymer of component (A) has a curing speed necessary for injection molding and has good flow moldability of the resin.

Examples of the bismaleimide represented by the formula (A) include N,N'-ethylene bismaleimide, LN'-hegizamethylene bismaleimide, l11. N'-4,4'-diphenylmethane bismaleimide, N,N'-4,4'-
Schiff J Nyl ether bismaleimide, N,N'-3,4
'-Diphenyl ether bismaleimide, N, N'-
m-xylene bismaleimide, N,)l'-1,4-cyclohexane bismaleimide, N,N'-4,4'-diphenylmethane bisninotraconimide, α,α'-bis(N-4-bis Maleimidophenyl)-m-diisopropylbenzene, α,α-bis(t4-bismaleimidophenyl>-p-diisopropylbenzene), and the like.

Among them, particularly preferred bismaleimides are represented by
N,N'-4,4'-diphenylmethane bismaleimide or N,N'-4,4'-diphenyl ether bismaleimide.

In addition to 4,4'-diaminocyclohexylmethane, examples of diamines represented by formula (B) include 1,4'-diaminocyclohegyzan, 100-phenylenediamine, and p-phenylenediamine. , 4.4'-diaminodiphenylmethane, 4.4'-diaminodiphenyl ether, 3.4'-diaminodiphenyl ether, 4.
Examples include 4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, ■-xylenecyamine, p-gysylene amine, and αα-his(4-aminophenyl)-m-diisobrobylberzene. It will be done.

Particularly preferred are 4,4'-diaminodiphenylmethane or 3,4'-diaminodiphenyl ether.

The molar ratio of these two components is (a) bismaleimide/(
When expressed as diamine (b), it is preferably from 1.5 to 1°, and particularly preferably from 2.0 to 5.0.

On the other hand, in the prepolymer of component (B) in the present invention, a network-like crosslinking reaction and a polymerization reaction in which linear chains are extended occur simultaneously during curing, thereby imparting high toughness.

Examples of the bismaleimide represented by formula (c) include N,N'-m-phenylenebismaleimide, N,N
'-p-pheny1 nonbismaleimide, N, N '1
．． 3-bisma 1 neuimido 4-methylbenzene, N, N
'.-4-chloro-f--7, nylene bismaleimide, N,N'-2-bromo p-phenylene bismaleimide, and the like.

Preferred are N,N'-m-phenylene bismaleimide, 11. N'-p-phenylene bismaleimide and 1,3-bismaleimide-4-methylbenzene.

Further, as the diamine represented by the formula (2), for example, 1,3-bis(4-aminophenoxy)benzene, J
, 4-bis(4-aminophenoxy)benzene, 1.6
-bis(4-aminophenoxy)biphenyl, 2.2-
Aromatic diamines such as bisE4-(4-aminophenoxy)phenylpropane and bis[4-(4-aminophenoquine)phenylkoketone are mentioned.

Among them, 1,3-bis(4-aminophenoxy)benzene and 1,4-bis(4-aminophenoxy)benzene are preferred.

The molar ratio of these two components is (c) bismaleimide/(
When expressed as diamine (d), 1.0 to 1.4 is preferable, and 1.1 to 1.3 is particularly preferable.

The reaction between component (c) and component (d) may be carried out in a molten state or in the presence of a small amount of a radical scavenger or carboxylic acid if necessary. A heating reaction is carried out in a solvent such as diglyme.

The reaction temperature is 80 to 200°C and the reaction time is about 5 minutes to 7 hours.

Then, the prepolymer of component (A) and the prepolymer of component (B) that have been explained so far are combined into 10
Component (B) is mixed in an amount of 20 to 100 parts by weight, preferably 50 to 100 parts by weight, based on 0 parts by weight.

If the mixing ratio of component (B) is less than 20 parts by weight, the toughness ('
This is because the effect of f''j' cannot be sufficiently obtained and if more than 100 parts by weight is mixed, the curing speed in the mold decreases and injection moldability decreases.

These two components can be blended by a conventional method using a kneader or the like.

In addition to the above-mentioned components, the prepolymers of component (A) and component (B) herein may contain ordinary additives, etc., to the extent that they do not impair the properties of each component. I don't mind if you stay there.

Furthermore, graphite, molybdenum disulfide, etc. may be added to improve sliding properties.

(Function) The polyimide composition of the present invention is a mixture of a prepolymer with fast heat curing speed and a prepolymer with high toughness in a predetermined ratio.

Therefore, a polyimide composition can be obtained that exhibits the curing speed and high toughness required for injection molding.

Such a polyimide composition reacts in the following manner during injection molding.

・First stage: The polyimide composition of the present invention, which is injected and filled into the mold, is rapidly cured by the reaction of the component (A), and its shape is maintained even after it is removed from the mold. The result is a molded product with incredible strength.

-Second stage...The polyimide molded body taken out from the mold is given toughness by reacting with the component (B) in the post-curing process.

Therefore, the obtained polyimide molded article has high toughness and is produced by injection molding.

2 (Example) Next, examples of the present invention will be described.

Examples 1 to 5 A prepolymer of component (A) was used, and in contrast, a prepolymer of (B) was used.
) component prepolymers were mixed in the proportions shown in Table 1.

This is a prepolymer obtained by heating reaction with a bismaleimide/diamine molar ratio of 2.5.

This is a prepolymer obtained by heating reaction with a molar ratio of 1.0.

In addition, graphite, molybdenum disulfide, and 3 was added to prepare a polyimide composition.

Using the polyimide composition thus obtained, II? 'sa5
A sheet of 1I1m was produced by injection molding and subjected to a strength test and an elongation test.

These results are shown in Table 1.

Comparative Example 1 A 5 mm thick sheet was produced by injection molding in the same manner as in Example using only the prepolymer of component (A).

Characteristic tests were conducted on this test piece under the same conditions as in the examples.

The results are shown in Table 1 together with the results of Examples.

Comparative Example 2 Using only the prepolymer of component (B), the thickness was 5+nm.
When an attempt was made to produce a sheet by injection molding, the curing speed in the mold was slow, resulting in poor shape and a good molded product could not be obtained.

(Margin below) 4 1 Table 5 As is clear from these results, the test sheet using the polyimide composition of the example can be produced by injection molding, and the impact strength and elongation are significantly improved. Was.

Moreover, the sliding properties were good and the shape was also excellent.

[Effects of the Invention] As explained above, the polyimide composition of the present invention achieves the curing speed necessary for injection molding by blending a prepolymer with a high thermosetting rate and a prepolymer with high toughness. A polyimide composition having high toughness can be obtained.

Therefore, the present invention greatly contributes to improving the quality of polyimide products and expanding the fields of application of polyimide compositions.

Claims (1)

[Claims] (1) (A) General formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(a) (In the formula, A represents a divalent organic group containing at least two carbon atoms. ) and the general formula: H_2N-B-NH_2...(b)(
In the formula, B represents a divalent organic group containing 30 or less carbon atoms. ) For 100 parts by weight of a prepolymer obtained by reacting with a diamine represented by , R_1, and R_2 each represent a hydrogen atom, methyl group, nitro group, cyano group, or halogen atom.) General formula: ▲ Numerical formula, chemical formula, table, etc. ▼・・・・・・
・(d) (In the formula,
, -C(CH_3)_2-, -C(CF_3)_2-,
It represents a divalent group of -S-, -SO_2 or -CO-. A polyimide composition characterized by blending a prepolymer obtained by reacting with a diamine represented by: 20 to 100 parts by weight.