JPH05117389A - Maleimide resin composition - Google Patents

Abstract

PURPOSE:To provide a resin composition excellent in the adhesiveness in a high-temperature atmosphere and the shear adhesiveness after left to stand in a high-temperature atmosphere, also good in fluidity, comprising each specific maleimide resin, diamine and imidazole. CONSTITUTION:The objective composition can be obtained by incorporating (A) 100 pts.wt. of a maleimide resin of formula I with (B) 30-110 pts.wt. of a diamine of formula II as curing agent and (C) pref. 0.2-5 pts.wt. of an imidazole of formula III as curing promoter, and, where appropriate, (D) pref. 0.5-200 (esp. 0.5-50) wt.%, based on the whole composition, of various ingredients (e.g. filler, pigment, flow regulator) followed by kneading in a molten state and then grinding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a maleimide resin composition having excellent heat resistance and fluidity.

[0002]

2. Description of the Related Art In recent years, powder compositions, such as powder coatings, are being replaced with solvent-based coatings that have been conventionally used over a wide range as pollution-free, resource-saving and energy-saving coatings. However, since general powder coatings have a high viscosity when melted, they have the advantage of enabling thick film finishing with a single coating operation, but on the other hand, wettability with the object to be coated and penetration into details. That is, it has a drawback that it is inferior in the gap filling property and the thin film coating property. Further, along with the expansion of applications in recent years, there has been a demand for improvement in heat resistance and adhesiveness as well as improvement in the above-mentioned drawbacks, and development of new materials is required to meet these demands.

Epoxy resin compositions have been widely used as the paints often used. The epoxy resin composition is mainly composed of an epoxy resin such as a bisphenol resin A type resin, a novolak type epoxy resin, an alicyclic epoxy resin, and a curing agent such as an acid anhydride and polyamine, and a tertiary amine. , Those containing a curing accelerator such as imidazole, a filler, and other additives are known.

[0004]

However, the heat resistance is limited in the epoxy resin composition, and it is difficult to cope with it in the field where higher heat resistance is required.

On the other hand, a resin composition containing a maleimide resin as a main component is mentioned as a material having excellent heat resistance. Although this material has improved heat resistance, the coating film formed is brittle and mechanical strength is lowered. However, as a result, there arises a problem that the adhesive force is significantly reduced.

The present invention has been made in view of such circumstances, and an object thereof is to provide a maleimide resin composition which is excellent in fluidity and heat-resistant adhesiveness and is also excellent in workability.

[0007]

In order to achieve the above object, the maleimide resin composition of the present invention has the following (A)
To (C) component, and the blending amount of the (B) component is set to 30 to 110 parts by weight with respect to 100 parts by weight of the (A) component. (A) A maleimide resin represented by the following general formula (1).

[Chemical 4] (B) A diamine resin represented by the following general formula (2).

[Chemical 5] (C) An imidazole resin represented by the following general formula (3).

[Chemical 6]

[0008]

That is, the present inventors have conducted a series of studies in order to obtain a maleimide resin composition having excellent fluidity and heat-resistant adhesiveness and excellent workability. As a result, the maleimide resin represented by the above general formula (1) as the main component,
The diamine resin represented by the general formula (2) is used as the curing agent, the imidazole resin represented by the general formula (3) is used as the curing accelerator, and the diamine resin is used in a specific ratio with respect to the maleimide resin. They have found that when used, they have excellent fluidity and can suppress a decrease in adhesive strength caused by thermal history due to continuous use in a high-temperature atmosphere and the like, and arrived at the present invention.

Next, the present invention will be described in detail.

The maleimide resin composition of the present invention is obtained by using a specific maleimide resin (component A), a specific diamine resin (component B) and a specific imidazole resin (component C).

The above specific maleimide resin (component A) is
It is represented by the following general formula (1) and is a commonly used bismaleimide resin, and has a characteristic of being significantly superior in heat resistance as compared with, for example, an epoxy resin, but on the other hand, its structural rigidity is large and mechanical It has the disadvantage of poor strength.

[0012]

[Chemical 7]

The specific diamine resin (component B) acts as a curing agent for the specific maleimide resin and is represented by the following general formula (2). This diamine resin is a substantially linear polymer.

[0014]

[Chemical 8]

The above-mentioned specific diamine resin (component B) has a higher linear chain than that of 4,4'-diaminodiphenylmethane (DDM) which is generally known as a curing agent for epoxy resins and maleimide resins. Because it has a molecular structure,
When used as a curing agent for a resin having a strong rigidity such as a maleimide resin, it gives flexibility to the cured product and is effective in relaxing internal stress. Further, when DDM or the like is used as a curing agent, a large number of bubbles, which are considered to be due to the sublimation gas of the curing agent, are generated at the time of melting the resin, and the resin may thicken and cannot be completely removed and remain as voids inside the resin. is there. On the other hand, the diamine resin (B component) represented by the general formula (2) hardly generates bubbles as described above (a polymer substance as compared with DDM, and may be sublimated). Is considered to be low), voids are less likely to remain inside the resin, and reliability is excellent. Also, regarding the flow characteristics,
Diamine resin represented by the general formula (2) (component B)
Has a characteristic not found in other curing agents such as DDM that the more it increases, the more it improves. This is because the diamine resin is a linear polymer and thus has low reactivity, so the gel time is relatively long, and the number of functional groups per unit is the maleimide resin represented by the general formula (1). It is considered that this is because the amount becomes smaller than that when it is cured by DDM.

The mixing ratio of the specific maleimide resin (component A) and the specific diamine resin (component B) is 30 to 110 parts of the diamine resin with respect to 100 parts by weight of the maleimide resin (hereinafter abbreviated as "part"). It must be set within the range. That is, when the amount of the diamine resin (component B) exceeds 110 parts, the heat resistance of the obtained maleimide resin composition decreases, and conversely, when it is less than 30 parts, the fluidity decreases.

The above specific imidazole resin (component C)
Acts as a curing accelerator and is represented by the following general formula (3).

[0018]

[Chemical 9]

The blending amount of the specific imidazole resin (component C) is 100 parts of the specific maleimide resin (component A).
It is preferable to set it in the range of 0.2 to 5.0 parts with respect to parts. That is, if the blending amount of the imidazole resin (component C) is less than 0.2 parts, the curing time may be long and the workability may be deteriorated. On the contrary, if it exceeds 5.0 parts, the melting time may be shortened and the fluidity may be deteriorated. This is because there is a tendency to do so.

In the maleimide resin composition of the present invention, in addition to the above-mentioned components A to C, various additives conventionally used can be appropriately blended if necessary.

Examples of the above various additives include fillers such as talc, silica sand, silica, calcium carbonate and barium sulfate, pigments such as carbon black, red iron oxide, titanium oxide, chromium oxide, cyanine blue and cyanine green, and other streams. Examples include regulators.

The amount of such additives to be added is usually preferably 0.5 to 200% by weight (hereinafter abbreviated as "%") of the total maleimide resin composition, and particularly preferably 0. 5 to 50%.

In the maleimide resin composition of the present invention, the components A to C and various additives are mixed by a conventionally known means such as a melt mixing method, and the components are pulverized and classified. Can be manufactured by.

The particle size in the classification is preferably set so as to pass through 30 mesh.

The maleimide resin composition thus obtained has a viscosity at the time of melting by the action of the above-mentioned specific maleimide resin (component A), specific diamine resin (component B) and specific imidazole resin (component C). It has a low porosity, excellent gap filling properties, good wettability with respect to an object to be coated and good coatability with a coating film, and has excellent heat resistance after curing.

[0026]

As described above, the maleimide resin composition of the present invention comprises the maleimide resin represented by the general formula (1), the diamine resin represented by the general formula (2), and the general formula (3). Since it is a resin composition containing an imidazole resin represented by the above formula (1) in a specific blending ratio, it has both excellent adhesive strength in a high temperature atmosphere and shear adhesive strength after being left in a high temperature atmosphere, and also has excellent flow characteristics.

Next, examples will be described together with comparative examples.

[0028]

Examples 1 to 11 and Comparative Examples 1 to 11 Tables 1 to 4 below
The components shown in Table 1 were blended in the proportions shown in the same table, melt-kneaded, and pulverized to obtain the target maleimide resin composition.

The maleimide resins A, epoxy resins B to D, diamine resins E and F in Tables 1 to 4 below,
The imidazole resin G is shown below.

[Maleimide resin A]

[Chemical 10]

[Epoxy resins B to D]

[Chemical 11] [In the above structural formula, the epoxy resin B is a = 0 to
1, epoxy resin C a = 2-3, epoxy resin D a
= 4-5. ]

[Diamine Resin E]

[Chemical 12]

[Diamine resin F]

[Chemical 13]

[Imidazole Resin G]

[Chemical 14]

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

[Table 3]

[0038]

[Table 4]

With respect to the maleimide resin compositions of Examples and Comparative Examples thus obtained, the shear adhesive strength at 250 ° C., the heat resistance rate, the gap filling rate, and the crack generation rate were measured and evaluated according to the following methods. did. The results are shown in Table 5 below.
~ Shown in Table 8.

(A) 250 ° C. shear adhesive strength Two steel sheets having a width of 10 mm, a length of 150 mm and a thickness of 1.0 mm were preheated at 250 ° C. and then lapped by 5 mm and bonded with this maleimide resin composition. Next, this is 250 ℃ ×
It was held for 20 minutes to be cured to prepare a shear adhesive strength test piece. Then, the shear adhesive strength of this test piece in an atmosphere of 250 ° C. was measured.

(B) Heat resistance The test piece prepared in the above shear adhesive strength test was left in an atmosphere of 250 ° C. for 1200 hours, then cooled to room temperature, the shear adhesive strength was measured, and the ratio to the initial adhesive strength ( %).

(C) Gap filling rate Two spacers having a thickness of 0.5 mm are sandwiched between two steel plates having a width of 10 mm, a length of 150 mm and a thickness of 1.0 mm at intervals of 10 mm, and the steel plates are heated to 250. When the temperature reached ℃, the maleimide resin composition was sprinkled into the slit-like gap formed between both steel plates and the spacer, and the melt was poured. Then, the mixture was held at 250 ° C. for 20 minutes to be cured, cooled to room temperature, and then the shear adhesive strength was measured. The shear adhesive strength was expressed as a ratio (%) to the initial shear adhesive strength obtained in (b) above.

(D) Crack generation rate The maleimide resin composition was heated at 230 ° C. to 80%.
A molded product of mm × 20 mm × 5 mm was prepared, and 20 minutes after the start of heating, it was cooled to room temperature. After cooling, the number of samples in which cracks were generated inside the cured body of the maleimide resin composition within 24 hours was shown as a ratio to the total number of measured samples.

[0044]

[Table 5]

[0045]

[Table 6]

[0046]

[Table 7]

[0047]

[Table 8]

From the results shown in Tables 5 to 8 above, the comparative examples have low shear adhesive strength, heat resistance, gap filling rate and crack generation rate. On the other hand, in the case of the example product, good values were obtained for all the test results. From this,
It can be seen that the example products are excellent in both heat resistance and fluidity.

Continued Front Page (72) Kenjiro Hayashi, 1-2 1-2 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto Denko Corporation

Claims (1)

[Claims] 1. The following components (A) to (C) are included:
A maleimide resin composition, wherein the blending amount of the component (B) is set to 30 to 110 parts by weight with respect to 100 parts by weight of the component (A). (A) A maleimide resin represented by the following general formula (1). [Chemical 1] (B) A diamine resin represented by the following general formula (2). [Chemical 2] (C) An imidazole resin represented by the following general formula (3). [Chemical 3]