JPS5846276B2 - resin paste - Google Patents

Description

[Detailed description of the invention] The present invention relates to a resin paste.

Conventionally, as resin pastes made of organic resins containing fillers, those using epoxy resins, phenol resins, etc. are well known.

However, since all of these resins have low heat resistance, pastes made with these resins have a usable temperature of 30
The temperature is about 0°C.

Heat-resistant resins such as aromatic polyimide, aromatic polyamideimide, and aromatic polyesterimide are known as paste resins that can be used at temperatures of 300° C. or higher.

However, in general, these heat-resistant resins have very poor solubility in solvents, and it is difficult to make the solution highly concentrated, so the amount of solvent in the paste is large, making it difficult to impart thixotropy. Pastes using this method had drawbacks such as a short pot life (tack time) after being applied to a substrate.

The present inventors conducted studies to improve the shortcomings of these conventional heat-resistant resins and resin pastes, and as a result, they arrived at the present invention.

That is, the present invention provides a polyamic acid obtained by reacting an aromatic tetracarboxylic acid ester obtained by reacting an aromatic tetracarboxylic dianhydride with an alcohol and/or an alcohol derivative with an amine and/or a diaminosiloxane. The present invention relates to a resin paste containing an ester oligomer and a filler.

The polyamic acid ester oligomer in the present invention is
If necessary, an aromatic tetracarboxylic acid ester obtained by reacting an aromatic tetracarboxylic dianhydride with an excess of alcohol or an alcohol derivative in the presence of a solvent is preferably added to an aromatic tetracarboxylic acid ester that is preferably approximately equal to the aromatic tetracarboxylic acid ester. It is obtained by reacting moles of aromatic diamine and/or diaminosiloxane.

As the solvent, one or more of ether glycol solvents such as butyl cellosolve, N-methyl-2-pyrrolidone, N,N-diethylformamide, and dimethyl sulfoxide are used.

Aromatic tetracarboxylic dianhydride has the general formula (where R
1 is a tetravalent aromatic hydrocarbon group.

), but for example, 3.3. '4.4'-benzophenonetetracarboxylic dianhydride, pyromellitic dianhydride, 3.3. '4.4'-diphenyltetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, 1.2.5.6-naphthalenetetracarboxylic dianhydride, 2.3.6,7-naphthalenetetracarboxylic dianhydride Acid dianhydride, 2.3.5.6-pyridinetetracarboxylic dianhydride, 1.4.5.8-naphthalenetetracarboxylic dianhydride, 3,4,9.10-perylenetetracarboxylic dianhydride Examples include anhydride, 4,4'-sulfonylsiphthalic dianhydride, etc., and one or more of these may be used.

In addition, examples of alcohols and alcohol derivatives for esterifying aromatic tetracarboxylic dianhydrides include monohydric alcohols such as methanol, ethanol, propatool, isopropyl alcohol, and butanol, ethylene glycol, phlopylene glycol, chrycerin, and trihydric alcohol. Examples include polyhydric alcohols such as methylolpropane, cellosolves, carpitols, etc., and one or more of these may be used.

Alcohol and alcohol derivatives may be used in combination.

Furthermore, the aromatic diamine used in the present invention has the general formula %formula% (Here, R2 is a divalent aromatic hydrocarbon group.

), for example, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4
．． There are 4'-diaminodiphenylsulfone, 4,4'-diaminodiphenyl sulfide, benzidine, metaphenylenediamine, paraphenylenediamine, 1,5-naphthalenediamine, 2,6-naphthalenediamine, etc., and these include one or two types. The above is used.

In addition, the diaminosiloxane used in the present invention (here, R3 is a divalent hydrocarbon group having 1 to 10 carbon atoms, R47R5
J R6+ R7 is a monovalent hydrocarbon group having 1 to 10 carbon atoms, and these may be the same or different.

n is an integer from 1 to 10), for example, etc., and these may be used alone or in combination of two or more.

Aromatic diamine and diaminosiloxane may be used together.

The esterification of aromatic tetracarboxylic dianhydride in the present invention is carried out using equimolar or excess mole of alcohol and/or alcohol derivative per mole of aromatic tetracarboxylic dianhydride.

The reaction temperature varies depending on the solvent, alcohol and alcohol derivative used, and is not particularly limited, but for example 3.3
．． When esterifying '4.4'-benzophenonetetracarboxylic dianhydride in N-methyl-2-pyrrolidone with ethanol, a reaction temperature of 80°C to 150°C is preferred.

Further, after esterification, it is possible to remove excess alcohol or alcohol derivative in order to adjust the concentration, but in this case, the temperature is preferably higher than the boiling point of the alcohol or alcohol derivative.

The next reaction between the aromatic tetracarboxylic acid ester and the aromatic diamine and/or diaminosiloxane is carried out using the aromatic tetracarboxylic acid ester in order to maximize the heat resistance of the polyimide compound obtained by curing the produced polyamic acid ester oligomer. It is preferable to use substantially equimolar amounts of aromatic diamine and/or diaminosiloxane.

In addition, in the reaction between aromatic tetracarboxylic acid ester and aromatic diamine and/or diaminosiloxane, if the reaction temperature is too high, the generated polyamic acid ester oligomer will imidize, its solubility will decrease, and it will precipitate. Preference is given to carrying out the reaction at a temperature of at most 90°C.

Regarding the polyamic acid ester oligomer thus produced, 200°C to 400°C, preferably 250°C to
If heat treatment is performed at 350°C, a polyimide resin with excellent heat resistance will be produced.

The above-mentioned polyamic acid ester oricomer-4ffJ solution is used in a resin paste, and a heat-resistant resin paste can be obtained by dispersing a filler in this solution.

The filler used in the present invention includes conductive powders such as metal powders such as silver and gold, carbon powders such as graphite and carbon black, etc., for the purpose of imparting conductivity.
A species or two or more species can be used, with silver powder being preferred.

When using silver powder, its content is preferably in the range of 50 to 90% by weight based on the total amount of the polyamic acid ester oligomer and silver powder.

If it is less than 50% by weight, the conductivity tends to decrease;
If the amount exceeds % by weight, it tends to become difficult to disperse the silver powder into the polyamic acid ester oligomer.

Furthermore, fillers such as metal oxides such as silica and alumina, and quartz glass powder can be used for the purpose of imparting thixotropy and improving the adhesiveness of the cured resin.

The above-mentioned polyamic acid ester oligomer is used in the resin paste as a solution of the polyamic acid ester oligomer, but as the solvent at this time, the solvent used in the production of the polyamic acid ester oligomer may also be used. Other solvents may also be used.

When the alcohol and/or ha-alcohol derivative is used in excess with respect to the aromatic tetracarboxylic dianhydride, these serve as a solvent, so it is not necessarily necessary to add another solvent.

Further, the resin paste of the present invention contains the above-mentioned polyamic acid ester oligomer solution and filler, and has adhesive properties itself, but if necessary, as an adhesion aid,
A coupling agent such as a silane type or a titanium type may be contained, and a coloring agent or the like may be contained as necessary.

The resin paste of the present invention is applied to a base material such as glass or metal by a dispensing method, a printing method, etc., and then applied at a temperature of 200°C to 400°C, preferably 250°C to
By performing heat treatment at 0° C., a polyimide resin composition with excellent heat resistance can be obtained.

When used as an adhesive, it can also be applied to an adherend using a dispensing method, a printing method, etc., lightly pressed, and then subjected to the same heat treatment as described above to obtain strong adhesion even at high temperatures. I can do it.

The resin paste of the present invention can obtain a cured product with extremely high heat resistance, has a long pot life (tack time) after being applied to a base material, and has a high concentration and low viscosity of the polyamic acid ester oligomer solution. Therefore, there is no limit to the amount of filler added, and properties such as thixotropy and conductivity can be easily imparted.

The present invention will be explained below with reference to Examples.

Example 1 3, 3. 322.1f of '4.4'-benzophenonetetracarboxylic dianhydride was added to N-methyl-2-pyrrolidone 7801, and dissolved by heating to 80°C.

Next, 50 f of methanol was added and the mixture was reacted at 150° C. for 3 hours, after which excess methanol was removed.

The solution thus obtained was cooled to 80°C and 4.4'-
Diaminodiphenylmethane 198. After adding Of8
The reaction was carried out at 0°C for 3 hours.

The obtained polyamic acid ester oligomer solution was 25
The viscosity was 3.0 poise at 8C.

Next, 50f of silver powder (Silvest TCG-1 manufactured by Tokuriki Kagaku Co., Ltd.) was added to the obtained polyamic acid Estyluo IJ coma solution 301, and the mixture was kneaded for 2 hours using a sieve machine to prepare a resin paste.

The viscosity of this paste was 1200 poise as measured at 25° C. using an E-HD type high viscosity analyzer at Q, 5 rpm, and the thixotropy was 70.

Moreover, the tack time was 10 hours or more.

Further, a cured product was prepared using this paste under curing conditions of 300°C for 30 minutes, and the heat resistance was measured, and the thermal decomposition initiation temperature was found to be 400°C or higher.

Also, when the conductivity was measured, the specific resistance was 3.0X10-5
It was Ωbi.

Next, glass plates were bonded using this paste under curing conditions of 250° C. for 30 minutes, and the adhesive strength was measured at 350° C., showing an adhesive strength of 50 to 7 or more per unit area.

Example 2 3, 3. '4.4'-benzophenone tetracarboxylic dianhydride 161.11 and pyromellitic dianhydride 1
09.11 was added to 700 g of N,N-diethylformamide and dissolved by heating to 80°C.

Next, ethanol 801 was added and the mixture was reacted at 1-20°C for 3 hours, after which excess alcohol was removed.

The solution thus obtained was cooled to 80°C and the 4,4'-
After adding 190 f of diaminodiphenyl ether and 12.4 l of 1,3 bis(aminopropyl)tetramethyldisiloxane, the mixture was reacted at 80° C. for 3 hours.

The obtained polyamic acid ester oligomer solution was 25
The viscosity was 2.0 poise at °C.

A resin paste was prepared in the same manner as in Example 1, and a thixotropic paste with good tack time, heat resistance, conductivity, and adhesiveness was obtained.

As shown in the examples, the resin paste of the present invention uses a polyamic acid ester oligomer with good solubility, so it has a long pot life (tack time) after being applied to a base material, and is suitable for printing methods, etc. It is easy to use the surface painting method.

Further, since the polyamic acid ester oligomer solution can be made to have a low viscosity even at a high concentration, there is no limit to the amount of filler added, and thixotropy and conductivity can be easily imparted.

In addition, while having these properties, the heat resistance was very good because the cured product after curing was similar to that of a normal polyimide resin composition.

Therefore, the resin paste of the present invention is useful for aircraft parts and electronic parts that require heat resistance, particularly for semiconductor chip bonding, conductive adhesive for light emitting diodes, and the like.

Claims (1)

[Claims] 1. A polyamic obtained by reacting an aromatic tetracarboxylic acid ester obtained by reacting an aromatic tetracarboxylic dianhydride with an alcohol and/or an alcohol derivative with an amine and/or a diaminosiloxane. A resin paste containing an acid ester oligomer and a filler. 2. The resin paste according to claim 1, wherein the filler is a conductive powder. 3. The resin paste according to claim 1, wherein the filler is silver powder. 4. The resin paste according to claim 3, wherein the content of silver powder is 50 to 90% by weight based on the total amount of polyamic acid ester oligomer and silver powder.