JPH101609A - Modified resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a modified resin for adhesives, etc., excellent in strength of the weld parts of moldings and capable of improving environmental stress- crack resistance characteristics by adding bismaleimide to an aromatic polysulfone resin and subjecting the resin to dynamic addition reaction with bismaleimide. SOLUTION: This modified resin is obtained by melting and kneading (A) 100 pts.wt. aromatic polysulfone resin with (B) 0.3-8 pts.wt. bismaleimide at 300-390 deg.C in 3-30min heat retention time so that the component B in an amount of 65-100wt.% based on charged amount of the component B is dynamically added to the resin and final addition amount of the component B becomes 0.2-8 pts.wt. Furthermore, a component A having a structural unit represented by formula I and/or formula II is preferably used as the component A and N,N'-(methylene-di-p-phenylene) bismaleimide is preferably used as the component B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a modified aromatic polysulfone resin. More specifically, the present invention relates to a modified aromatic polysulfone resin excellent in the strength of a weld portion of a molded product, its environmental stress cracking resistance, and adhesion to a metal.

[0002]

2. Description of the Related Art Aromatic polysulfone resins have excellent characteristics such as heat resistance, mechanical strength and flame retardancy, and are widely used as engineering plastics in the field of metal replacement.

[0003] Since the resin is amorphous, it is affected by some polar solvents such as ethers and ketones, and cracks are liable to occur (especially environmental stress cracking is likely to occur when the resin comes into contact with these solvents during stress loading). )There's a problem. In particular, when a molded product obtained by injection molding has a weld portion (flow-bonded portion of a molten resin), this problem appears remarkably.

In recent years, the resin has been increasingly used as a material for IC sockets such as burn-in sockets and PGA sockets in the field of electric and electronic parts. In this type of application, there are many occasions where the molded article comes into contact with a cleaning agent for washing off the soldering flux of the IC. In recent years, there has been a strong tendency to replace detergents with ether-based ones in order to eliminate chlorofluorocarbons. Therefore, environmental stress cracking in welds, such as screwed parts and places where IC pins are inserted, is a new problem. Began to be recognized.

For the purpose of improving general chemical resistance of the resin, alloying with a crystalline thermoplastic resin has been studied. For example, Japanese Patent Publication No. 5-87541 discloses an aromatic polysulfone resin and an aromatic polysulfone resin. Japanese Patent Application Publication No. Sho 60-11063 discloses a technique for alloying with a polyetherketone resin and a technique relating to an alloy with a polyphenylene sulfide resin. However, in these systems, although the chemical resistance in a general sense is improved, the weld strength is reduced, and there is a problem that the environmental stress cracking of the weld is not improved.

On the other hand, aromatic polysulfone resins have applications in heat-resistant varnishes. In this case, the aromatic polysulfone resin and other necessary components are dissolved and / or dispersed in a solvent, applied to a substrate (often a metal), and baked. Is more preferred. Japanese Patent Publication No. 55-8351 discloses a technique for increasing the strength of a coating film by making a part of the molecular chain terminal group of an aromatic polyether sulfone resin a hydroxyl group. This utilizes the fact that the degree of polymerization is increased by reacting with oxygen in the air during the baking process, but according to the results obtained by the inventors, this technique makes it possible to reduce the thickness of the coating film and the peel strength. There is a strong negative correlation between them, and there is a problem that the thicker the coating film, the easier it is to peel off.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a modified polysulfone resin in which the weld portion of a molded article has improved resistance to environmental stress cracking and adhesion to metal.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, added bismaleimide to an aromatic polysulfone resin, and melt-kneaded in a kneading machine to form a dynamic kneader. It has been found that the above object can be achieved by causing an addition reaction, and the present invention has been completed.

That is, the present invention relates to an aromatic polysulfone resin 1
And 100 parts by weight of bismaleimide and 0.3 to 8 parts by weight of bismaleimide, wherein 0.2 to 8 parts by weight of bismaleimide is added to an aromatic polysulfone resin. The present invention relates to a modified aromatic polysulfone resin having improved properties.

[0010] The aromatic polysulfone resin used in the present invention comprises a monomer having a difunctional phenolate obtained by the action of an alkali on a difunctional phenol and a monomer having a difunctional aromatic halogen group activated with an electron-withdrawing sulfone. It is a polymer obtained by performing a condensation reaction in an aprotic polar solvent, and has an arylene bond, an ether bond and a sulfone bond as essential bond units. As a very typical example, for example, the formula (1)
To (4) and a polymer having a structural unit represented by the formula (6), and these may be used alone or in combination of two or more.

[0011]

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[0012]

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[0013]

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[0014]

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These aromatic polysulfone resins are described, for example, in JP-B-40-10067 and JP-B-42-779.
No. 9 and JP-B-47-617 can be easily produced.

In the present invention, those comprising only the structural unit of the formula (1), those comprising only the structural unit of the formula (2), or those comprising both are particularly preferably used. The meaning of containing both means that the amount of the bisphenol A residue to the diphenylsulfone residue is 0 to 50 mol%.
Point that it can be changed within the range.

The weight average molecular weight of the aromatic polysulfone resin used in the present invention is in the range of 20,000 to 50,000, more preferably 30,000 to 40,000 (polyethylene oxide) as measured by gel permeation chromatography. Conversion value) is preferable. When the weight average molecular weight is less than 20,000, the effect of improving the environmental stress cracking resistance of the modified resin of the present invention may be insufficient, and when it exceeds 50,000, the moldability may be poor.

The bismaleimide used in the present invention is a compound having a structure represented by the formula (5) (Formula 7).

[0019]

Embedded image (In the formula, R is a single unit or a combination of two or more types of structural units represented by-(CH ₂ ) _n- , -Ar (R ') _m- , -O-, and n is an integer of 1 to 6. , Ar represents an arylene, R ′ represents an alkyl group or a halogen group having 1 to 5 carbon atoms, and m represents an integer of 0 to 4.) For example, N, N ′-(methylene-di-p-phenylene) bismaleimide, N, N ′-(methylene-p-phenylene) bismaleimide, N, N′-m-phenylenebismaleimide, N, N′-hexamethylenebismaleimide,
N, N ′-(oxy-di-p-phenylene) bismaleimide, N, N ′-(methylene-di-3-methyl-p-phenylene) bismaleimide and the like, and bismaleimide alone or in combination of two or more Used as a mixture.

In the present invention, those having a structure in which R in the formula (5) contains an aromatic ring and has no side chain are preferred from the viewpoint of heat resistance. In particular, N, N '-(methylene-di-p-phenylene) bismaleimide is preferred. It is preferable because it can be obtained at low cost as a so-called thermosetting monomer for polybismaleimide resin.

An important requirement in the present invention is that bismaleimide is dynamically added to the aromatic polysulfone resin by hot-melt kneading (chemical modification). The “state in which bismaleimide is added to the aromatic polysulfone resin” as used herein means that the added bismaleimide is not eluted from the denatured resin even after extraction with a 20% by volume methanol solution of chloroform, and N-methyl- 2-pyrrolidone refers to those that dissolve without residue. That is, it is not that the bismaleimide is not extracted because only the thermal curing of the bismaleimide alone has occurred (gelled).

As the method for producing the modified resin, a generally known method can be adopted. However, after uniformly mixing the aromatic polysulfone resin and bismaleimide, the mixture is melt-kneaded with a single-screw or multi-screw extruder and continuously mixed. It is preferred to produce. In the present invention, an initiator such as a radical generator is not required.

In the present invention, the aromatic polysulfone resin 100
The bismaleimide is added in the range of 0.3 to 8 parts by weight based on the weight of the bismaleimide, and the final addition amount is in the range of 65 to 100% by weight of the charged amount of the bismaleimide, ie, in the range of 0.2 to 8 parts by weight. It is necessary that As a production condition of the modified resin satisfying such conditions, the kneading temperature is set to 300 to 39.
A suitable result is obtained when the temperature is in the range of 0 ° C. and the heat residence time is in the range of 3 to 30 minutes. If the kneading temperature is less than 300 ° C., the addition reaction of bismaleimide may not proceed sufficiently,
On the other hand, if the temperature exceeds 390 ° C., decomposition of the aromatic polysulfone resin or bismaleimide may occur, which is not preferable. Similarly, if the heat residence time is less than 2 minutes, the addition reaction of bismaleimide may not proceed sufficiently, and if it exceeds 30 minutes, decomposition of the aromatic polysulfone resin or bismaleimide may occur, which is not preferable.

When the added amount of bismaleimide is less than 0.2 parts by weight, the modified resin of the present invention may have an insufficient effect of improving the environmental stress cracking resistance at the weld portion (which is the main point). Exceeding the weight part is not preferred because the weld strength itself may be reduced or bismaleimide may preferentially cure and lose the thermoplasticity.

When the modified aromatic polysulfone resin obtained as described above is used as an adhesive or varnish for increasing the metal / metal or metal / resin interface strength, any of a wet method and a dry method can be used. In the case of a wet method, the modified resin is dissolved and / or dispersed in a solvent, for example, N-methyl-2-pyrrolidone or a mixed solvent mainly containing the modified resin, and further, necessary components are dissolved and / or dispersed, and then applied to a substrate. , 320-380 ° C. In the case of a dry method, powder, pellets, tablets or sheets of modified resin are brought into contact with each other by sandwiching them between base materials.
It is preferable to perform pressure bonding in the range of 20 to 380 ° C. What is important is that a composition obtained by simply mixing an aromatic polysulfone resin and a bismaleimide in a wet or dry manner cannot provide an adhesive strength. The effect cannot be obtained unless melt kneading is performed by a kneader and modification by addition reaction is not advanced. The above-mentioned modified aromatic polysulfone resin may be used in accordance with the purpose and application of other thermoplastic resins, various elastomers, various additives, various fillers, etc. within a range that does not impair the characteristics of the present invention in any application. it can.

[0026]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The measurement and evaluation of the physical properties of the resins in Examples and Comparative Examples were performed in the following manner. (1) Addition rate of bismaleimide Pellets (cutouts of molded products only in Comparative Example 7) were 360
A film having a thickness of 10 μm was prepared by hot pressing at 0 ° C., which was subjected to Soxhlet extraction to which bismaleimide remaining without being extracted was added, and the addition rate was determined. Here, the extraction solvent used was a 20% by volume methanol solution of chloroform, and the extraction time was 7 hours. Here, the addition rate of bismaleimide was determined by the following equation by measuring the infrared absorption spectrum. (A1700 ′ / A1100 ′) / (A1700 / A1100) × 100 A1700: Absorbance of absorption at 1700 cm ⁻¹ derived from carbonyl group of bismaleimide before extraction A1700 ′: 1700 cm derived from carbonyl group of bismaleimide after extraction ^-1 absorbance of the A1100: absorbance of A1100 of 1100 cm ^-1 derived from a sulfonic group of the aromatic polysulfone resin before extraction ': derived from a sulfonic group of the aromatic polysulfone resin after extraction of the absorption of 1100 cm ^-1 A1100 of absorbance (2) Addition amount of bismaleimide The product of the charge amount of bismaleimide and the addition ratio obtained in the above (1) per 100 parts by weight of the aromatic polysulfone resin. (3) Gel fraction Pellets (cutouts of molded articles only in Comparative Example 7) were dissolved in N-methyl-2-pyrrolidone at room temperature to obtain a 3% by weight solution, and this solution was filtered using a G5 glass filter. Then, the dry weight of the residue was measured to determine the gel fraction.

(4) Environmental stress cracking test of weld part A constant bending stress (400 k) is applied to the weld part of a bending test piece (width 1/2 ", thickness 1/8") having a weld at the center.
gf / cm ² ), and at room temperature at room temperature, a cleaning agent for ICs (manufactured by Kao Corporation, trade name: Cleanthrough 750H, mainly composed of monoalkyl ether of diethylene glycol).
Alternatively, it was immersed in methyl cellosolve, and the state after 3 hours was visually evaluated. Here, those with no change in appearance are marked with ○,
Those with cracks and cracks were rated as x, and those that broke only by applying stress were rated as xx. (5) Tensile test Based on JIS-K7113. Here, both those with and without a weld at the center of the test piece were evaluated. The ratio between the two values was taken as the retention rate. (6) Bond strength test with metal (tensile shear bond strength) Based on JIS-K6850. SUS as adherend
304 strips, two of them are overlapped and the width is 12.5mm
And sandwich 0.2 g of pellets (compressed tablets of powder in Comparative Example 7 only) at 360 ° C./200 kgf
After pressing and fusing for 1 minute under the condition of / cm ² , JIS
A tensile test according to -7113 was performed to measure the strength. (7) Film strength test for metal (cross cut tape peel test) Based on JIS-K5400. SUS3 as base material
No. 04 plate, 20 wt% N-methyl-
After the 2-pyrrolidone solution was applied and baked at 350 ° C. for 30 minutes, a grid was cut at 1 mm incision intervals, a cellophane tape was stuck and peeled off, and the state after tape peeling was observed. The thickness of the coating film was 10 μm and 30 μm.
In this method, a score is expressed using an even number between 0 and 10, and a larger number indicates a better one with less peeling.

Example 1 An aromatic polysulfone resin having a structural formula of the above formula (1) (trade name, Ultrason E-3010, manufactured by BASF)
Hereinafter, "aromatic polysulfone resin 1", weight average molecular weight 3
5000) and N, N '-(methylene-di-p-phenylene) bismaleimide (manufactured by Mitsui Toatsu Chemicals, Inc., hereinafter referred to as "bismaleimide 1") in the proportions shown in Table 1, and then a tumbler mixer is sufficient. And screw diameter 37
The mixture was melt-mixed with a twin-screw extruder having an L / D of 32 mm at 350 ° C. and a screw rotation speed of 80 rpm, and extruded to obtain a pellet-shaped modified resin. The heat residence time at this time is from 3 minutes to 6
Minutes. The pellets were used to evaluate the “bismaleimide addition rate and gel fraction / tensile shear adhesive strength / cross-cut tape peel test”. Pellets 38
Molded into test pieces with an injection molding machine set at 0-360 ° C,
"Environmental stress cracking resistance / tensile rupture strength at weld" was evaluated. The heat residence time in the injection molding machine at this time is about 1
Minutes. Table 1 shows the results.

Example 2 The bismaleimide 1 of Example 1 was replaced with N, N '-(methylene-
Di-3-methyl-p-phenylene) bismaleimide (manufactured by Mitsui Toatsu Chemicals, Inc .; hereinafter, “bismaleimide 2”) was used, and the other conditions were evaluated as in Example 1. Table 1 shows the results.

Example 3 Bismaleimide 1 of Example 1 was changed to N, N'-m-phenylenebismaleimide (manufactured by Mitsui Toatsu Chemicals, Inc .; hereinafter, "bismaleimide 3"), and the other conditions were the same as those of Example 1. The same evaluation was performed. Table 1 shows the results.

Example 4 An aromatic polysulfone resin having a structural formula of the above formula (2) (trade name, Ultrason S-3010, manufactured by BASF)
Hereinafter, "aromatic polysulfone resin 2", weight average molecular weight 3
3000) and bismaleimide 1 were blended in the proportions shown in Table 2, and the other conditions were evaluated as in Example 1. Table 2 shows the results.

Example 5 Bismaleimide 1 of Example 4 was replaced with bismaleimide 2
Other conditions were evaluated as in Example 1. Table 2 shows the results.

Example 6 Bismaleimide 1 of Example 4 was replaced with bismaleimide 3.
Other conditions were evaluated as in Example 1. Table 2 shows the results.

Examples 7 to 8 The same conditions as in Example 1 were evaluated except that the amount of bismaleimide 1 added in Example 1 was changed. Table 3 shows the results.

Examples 9 to 10 The same conditions as in Example 1 were evaluated except that the amount of bismaleimide 1 added in Example 4 was changed. Table 3 shows the results.

COMPARATIVE EXAMPLE 1 Aromatic polysulfone resin 1 and polyetherketone resin (PEEK450P, manufactured by Victrex Corp.) were blended in the proportions shown in Table 2, and the other conditions were the same as in Example 1. In this case, "Weld part environmental stress cracking resistance
Only the tensile strength at break was evaluated in the same manner as in Example 1.
Table 4 shows the results.

Comparative Example 2 The aromatic polysulfone resin 1 of Comparative Example 1 was replaced with the aromatic polysulfone resin 2, and the other conditions were the same as in Example 1.
In this case as well, only the “environmental stress cracking resistance / tensile rupture strength” of the weld portion was evaluated in the same manner as in Example 1. Table 4 shows the results.

Comparative Example 3 The polyetheretherketone resin of Comparative Example 1 was a polyphenylene sulfide resin (manufactured by Topren Co., Ltd., trade name: Topren LN-2), and the other conditions were the same as in Example 1. In this case as well, only the “environmental stress cracking resistance / tensile rupture strength” of the weld portion was evaluated in the same manner as in Example 1. Table 4 shows the results.

Comparative Example 4 The polyetheretherketone resin of Comparative Example 2 was a polyphenylene sulfide resin, and the other conditions were the same as in Example 1. In this case as well, only the “environmental stress cracking resistance / tensile rupture strength” of the weld portion was evaluated in the same manner as in Example 1. Table 4 shows the results.

COMPARATIVE EXAMPLE 5 The amount of bismaleimide 1 added in Example 1 was outside the preferred range, and the other conditions were evaluated as in Example 1. Table 5 shows the results.

Comparative Example 6 Evaluation was made as in Example 1 except that the amount of bismaleimide 1 added in Example 1 was less than a suitable range. Table 5 shows the results.

Comparative Example 7 A powder blend of aromatic polysulfone resin 1 and bismaleimide 1 having the same compounding ratio as in Example 1 was directly injection molded without extruding with a twin screw extruder and evaluated. The heat residence time in the injection molding machine at this time was also about 1 minute. Table 5 shows the results. Only in this case, the term “addition rate / addition amount” is a measured value obtained by cutting out a molded product and hot-pressing it to form a film. In the “Gel fraction / cross cut tape peeling test”, a molded product was cut out and N-
It is a measured value obtained by dissolving in methyl-2-pyrrolidone. "Tensile shear adhesive strength" was evaluated by using a powder blend having the same composition as a tablet with a tableting machine for infrared absorption measurement and using the tablet. Table 5 shows the results.

Comparative Example 8 In Example 4, the temperature of the twin-screw extruder was set to 280 ° C., and the other conditions were evaluated in the same manner as in Example 1. Table 5 shows the results.

Comparative Example 9 The aromatic polysulfone resin 1 alone was evaluated. Table 6 shows the results.

Comparative Example 10 The evaluation was made using the aromatic polysulfone resin 2 alone. Table 6 shows the results.

Comparative Example 11 Using an aromatic polysulfone resin (trade name: 5003P, manufactured by Sumitomo Chemical Co., Ltd .; hereinafter, referred to as "aromatic polysulfone resin 3") having a hydroxyl group-enriched molecular chain terminal, "tensile shear adhesive strength / cross cut" Only the "tape peel test" was evaluated. Table 6 shows the results.

[0047]

[Table 1]

[0048]

[Table 2]

[0049]

[Table 3]

[0050]

[Table 4]

[0051]

[Table 5]

[0052]

[Table 6]

[0053]

Industrial Applicability The modified aromatic polysulfone resin of the present invention is excellent in the strength of the weld portion of the molded article and can improve the resistance to environmental stress cracking, and its application is not limited as in the conventional aromatic polysulfone resin. A wide range of applications in the electrical and electronic fields are possible. Also, it has excellent metal adhesion and can be applied as an adhesive or a varnish composition.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Sachino Hiruda 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Mitsui Toatsu Chemicals Co., Ltd.

Claims (6)

[Claims] 1. A modified resin comprising 100 parts by weight of an aromatic polysulfone resin and 0.3 to 8 parts by weight of bismaleimide, wherein 0.2 to 8 parts by weight of bismaleimide is added to the aromatic polysulfone resin. 2. 100 parts by weight of an aromatic polysulfone resin and 0.3 to 8 parts by weight of bismaleimide are heated at a temperature of 300 to
Melt and knead in a range of 390 ° C. and a heat residence time of 3 to 30 minutes, and 65 to 100% by weight of the charged amount of bismaleimide
The modified resin according to claim 1, wherein the modified resin is dynamically added to make the final addition amount of bismaleimide 0.2 to 8 parts by weight. 3. An aromatic polysulfone resin of the formula (1)
The modified resin according to claim 1, wherein a structural unit represented by formula (1) and / or formula (2) (formula 2) is used. Embedded image Embedded image 4. The modified resin according to claim 1, wherein N, N ′-(methylene-di-p-phenylene) bismaleimide is used as the bismaleimide. 5. An adhesive using the modified resin according to claim 1. 6. A varnish composition using the modified resin according to claim 1.