JPH03212474A - Adhesive composition and its production - Google Patents

Abstract

PURPOSE:To obtain the composition containing a phenol resin, butylal resin, epoxy resin, noncarboxylated acrylonitrile-butadiene copolymer and carboxylated acrylonitrile-butadiene copolymer at a specific ratio and having excellent adhesion and heat resistance to soldering. CONSTITUTION:The objective composition containing (A) phenolic resin, (B) butylal resin, (C) epoxy resin, (D) non-carboxylated acrylonitrile-butadiene copolymer [preferably having >=27-45wt.% acrylonitrile content and 1-10wt.% carboxylic acid content and being >50ML1+4 in Mooney viscosity at 100 deg.C] being solid at 25 deg.C and (E) carboxylated acrylonitrile-butadiene copolymer (preferably having 20-40wt.% acrylonitrile content and 1-10wt.% carboxyl group content) being solid at 25 deg.C at blend amounts of the component D of 10-80 pts.wt. and the component E of 10-80 pts.wt. based on 100 pts.wt. total amount of these components A to C.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an adhesive composition having excellent adhesive properties and soldering heat resistance, and a method for producing the same.

[Conventional technology]

Conventionally, phenolic resin/butyral resin adhesives, epoxy resin adhesives, acrylic resin adhesives, etc. have been widely used as adhesives for producing flexible printed circuit boards, and acrylonitrile has also been used as the adhesive for the above adhesives. - Improved adhesives containing butadiene copolymer (hereinafter referred to as rNBRJ) have been proposed and used in some cases (JP-A-49-33987, JP-A-61-2).
No. 13277, No. 49-33988.

61-100445, 61-108679, 50-72930, 63-3074, 58-202583, 60-7907
Publication No. 9, etc.). The above adhesive is made by adding NBR to phenol resin, butyral resin, and epoxy resin alone or in combination.By blending NBR in this way, it improves adhesiveness, soldering heat resistance, chemical resistance, and flexibility. The purpose of this is to improve the properties such as flexibility.

[Problem to be solved by the invention]

However, among the above adhesives, among the above characteristics, adhesives with excellent peel strength (adhesiveness) at room temperature (approximately 25°C) have poor soldering heat resistance, and conversely, adhesives with excellent soldering heat resistance The adhesive has poor adhesive properties, and the reality is that a product that can simultaneously satisfy both adhesive properties and soldering heat resistance has not yet been obtained.

The present invention was made in view of the above circumstances, and an object thereof is to provide an adhesive having excellent adhesive properties and soldering heat resistance, and a method for producing the same.

[Means to solve the problem]

In order to solve the above object, the present invention provides the following (A) to
Contains component (E), the blending amount of component (D) is 10 to 80 parts by weight per 100 parts by weight of components (A) to (C);
The first aspect is an adhesive composition in which the amount of the component (A) is set to be 10 to 80 parts by weight, and (A) a phenolic resin.

(B) Butyral resin.

(C) Epoxy resin.

(D) Non-carboxylated acrylonitrile-butadiene copolymer solid at 25°C.

(E) Carboxylated acrylonitrile-butadiene copolymer solid at 25°C.

The second gist is an adhesive composition consisting of a solution A formed by dissolving the following components (A) to (C) and a solution B formed by dissolving the following components (D) and (E), (A) (B) (C) (D) (E) Phenol resin.

Butyral resin.

Epoxy resin.

Solid non-carboxylated acrylate at 25°C Ronitrile-butadiene copolymer.

Carboxylated acrylic solid at 25°C Li B Nitrile-butadiene copolymer.

A step of uniformly dissolving the following components (A) to (C) in an organic solvent containing an alcohol-based organic solvent as a main component, and a step of uniformly dissolving the following components (D) and (E) in a ketone-based organic solvent. The third gist is a method for producing an adhesive composition comprising the steps of: 1. and a step of uniformly mixing both liquids.

(A) Phenol resin.

(B) Butyral resin.

(C) Epoxy resin.

(D) Non-carboxylated acrylonitrile-butadiene copolymer solid at 25°C.

(E) Carboxylated acrylonitrile-butadiene copolymer solid at 25°C.

It should be noted that the term "main component" here includes the case where the entire component consists only of the main component.

[Effect]

In other words, in order to obtain an adhesive composition with excellent adhesive properties and soldering heat resistance, the inventor conducted a series of researches and found that the inventors have developed an adhesive composition that has traditionally been used in organic solvents, mainly alcohol-based organic solvents. It uniformly dissolves a mixed base resin consisting of three types of phenolic resin, butyral resin, and epoxy resin, and also adds solid non-carboxylated NBR, which contributes to improved adhesiveness, to the ketone organic solvent, and contributes to improved soldering heat resistance. If solid carboxylated NBR is uniformly mixed with the above-mentioned mixed base resin at a specific ratio, and these two liquids are uniformly mixed in advance or just before use, a product with excellent adhesiveness and soldering heat resistance can be obtained. The present invention was achieved by discovering that it can be obtained.

The adhesive composition of the present invention uses a phenolic resin (component A), a butyral resin (component B), and an epoxy resin (component C) as a mixed base resin, in addition to which uncarboxylated NBR (component D) and carboxylated It is obtained by using NBR (component E) and an organic solvent that dissolves these, and is in a -liquid or two-liquid form.

The first aspect of the present invention is a one-liquid type, and the second aspect is a one-liquid type.
The gist of this is a two-liquid type.

The phenol resin (component A) is not particularly limited, but an ammonia aresol type phenol resin obtained by condensation polymerization using ammonia, hexamethylenetetrazine, etc. as a catalyst is usually preferably used. In addition to the above ammonia resol type phenol resin, other resol type phenol resins, novolac type phenol resins, alkyl phenol resins, etc. can also be used in combination.

Further, the above-mentioned butyral resin (component B) is not particularly limited like the above-mentioned phenol resin, but when the adhesive composition of the present invention is used for flexible printed circuit boards, for example, butyral resin with a polymerization degree of 1700 or more is used. It is preferable to use a material having a degree of oxidation of 65 mol% or more.

Further, the above-mentioned epoxy resin (component C) is not particularly limited like the above-mentioned phenol resin and butyral resin, and conventionally known ones can be used, such as bisphenol type, phenol novolac type, talesol novolak type, and cyclic aliphatic resin. Group type epoxy resins are used, and those having an epoxy equivalent of 150 to 1000 are generally used.

The mixing ratio of the above A-C components is not particularly limited, but is usually a solid content ratio (parts by weight (hereinafter referred to as "parts")).
(abbreviated as )), and it is preferable to set it as follows.

Phenol resin (A component) 20-50 parts Butyral resin (B component) 30-70 parts Epoxy resin (C component)
5 to 30 parts Next, non-carboxylated NBR (D component) used together with the above mixed base resin (A-C components)
As such, it is necessary to use one that is solid at room temperature (25°C). And, as the above-mentioned non-carboxylated NBR,
Acrylonitrile content is 27-45% by weight (hereinafter "%")
), and the Mooney viscosity is JIS-6300.
In the test method, it is preferable to use a material with a value of 50MLL+4 or more at 100°C. More preferably, the acrylonitrile content is 33 to 43% and the Mooney viscosity is 50 or more, and even more preferably, the Mooney viscosity is 60 to 80. That is, if the acrylonitrile content exceeds 45%, the solubility of the non-carboxylated NBR in a solvent decreases, and conversely, if it is less than 27%, the effect of improving adhesion becomes insufficient.

Moreover, if the Mooney viscosity is less than 50, the effect of improving adhesiveness will still be insufficient.

The blending ratio of the above non-carboxylated NBR (component D) is:
It is necessary to set the blending ratio to 10 to 80 parts, preferably 20 to 70 parts, with respect to 100 parts of the mixed base resin consisting of the above A-C components. That is, if the blending ratio of component D is less than 10 parts, a sufficient effect of improving the adhesive strength cannot be obtained, whereas if it exceeds 80 parts, the adhesive strength is improved but the soldering heat resistance is decreased.

As the above-mentioned carboxylated NBR (component E), it is necessary to use one that is solid at room temperature (25° C.) like the above-mentioned components. The carboxylated NBR preferably has an acrylonitrile content of 20 to 40% and a carboxyl group content of 1 to 10%.

The blending ratio of such carboxylated NBR (component E) needs to be set at a blending ratio of 10 to 80 parts with respect to 100 parts of the mixed base resin consisting of the above A-C components,
Preferably it is 20 to 70 parts. That is, if the blending ratio of component E is less than 10 parts, a sufficient effect of improving soldering heat resistance cannot be obtained, and if it exceeds 80 parts, the adhesiveness will decrease.

In addition, the above two types of NBR (D component, E component) have a Mooney viscosity of 100 in the JIS-6300 test method.
At 50 ML1+4 or higher at ℃, mastication with a roller may be performed before dissolution. By performing mastication in this way, the compatibility of the two types of NBR (separation stability of uniformly dissolved components of component D and component E) can be improved. can be further improved.

In addition, as the above two types of NBR (D component, E component) used in the present invention, metal ions (Na・, Cu'', etc.)
It is more preferable to use an adhesive composition manufactured with a reduced content of halogen ions (CCl-, etc.), as the electrical properties (electrical insulation properties) of the adhesive composition of the present invention are improved.

In addition, in addition to the above-mentioned A-E components, other additives such as anti-aging agents, epoxy resin curing agents, and metal ion sequestering agents may be appropriately blended into the adhesive composition of the present invention, as necessary. .

The above-mentioned anti-aging agent is an amine-ketone type.

Examples include aromatic amine type, monophenol type, bisphenol type, benzimidazole type, and thiourea type.

Examples of the epoxy resin curing agent include imidazoles, dicyandiamide, modified fatty acid amines, aromatic amines, acid anhydrides, and mercaptans.

Further, examples of the metal ion sequestering agent include benzotriazole, imidazole compounds, silane compounds, chelate forming compounds such as hydroxypropylethylenediamineethylenediaminetetraacetic acid, and the like.

Furthermore, organic solvents for dissolving the above components include methanol, ethanol, propatool, isopropatool (
IPA), alcohols such as butanol and amyl alcohol, ketones such as acetone, methyl ethyl ketone (MEK) and methyl isobutyl ketone, aromatics such as benzene, toluene and xylene, ethyl acetate, butyl acetate, ethyl formate, propyl formate, Esters such as amyl formate, methyl propionate, ethyl propionate, ethylene glycol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, cellosolve acetate methyl carbitol, ethyl carbitol and their derivatives, nitrohydrocarbons such as nitromethane, nitroethane, etc. These can be used alone or in combination.

The adhesive composition of the present invention is usually produced as follows. That is, the components A to E each have different solubility in the organic solvent and compatibility between the resins,
Each component tends to separate if left for a long time, so
The A-E components are classified into two groups, and the A-C components are uniformly mixed in the alcoholic organic solvent (single solvent or mixed solvent) to prepare a solution A. Separately from this solution A, solution B is prepared by uniformly mixing the above components and component E in the ketone organic solvent (single solvent or mixed solvent). Then, it can be produced by adding and mixing solution B to solution A while stirring at high speed and uniformly dispersing it. The adhesive composition thus obtained is in liquid form and is usually adjusted to have a solids content of 15 to 30%.

The above-adjusted adhesive composition maintains separation stability for about 2 days to 2 weeks, but if left for a longer period than this, the adhesive composition may separate, so it must be re-used before use. It is best to use the mixture after stirring to uniformly disperse it. In addition, for two-liquid products, prepare solution A as described above.
and solution B, and produce a product using these as a two-component system. This two-liquid product is stored as it is and stirred and mixed immediately before use as an adhesive.

The adhesive composition obtained in this way contains non-carboxylated NBR and carboxylated NBR in the mixed base resin consisting of the above-mentioned phenol resin, butyral resin and epoxy resin.
It has excellent adhesive properties and soldering heat resistance due to the action of R. Therefore, such an adhesive is suitably used, for example, as an adhesive between a copper foil circuit pattern and a film layer such as polyimide when producing a flexible printed circuit board.

[Effects of the Invention] As described above, the adhesive composition of the present invention includes a -liquid type and a two-liquid type, as well as a phenol resin, a butyral resin, an epoxy resin, a non-carboxylated NBR that is solid at room temperature, and a non-carboxylated NBR that is solid at room temperature. Because it is used in combination with carboxylated NBR, adhesiveness and soldering heat resistance are significantly improved. Therefore, it is extremely useful as an adhesive for bonding polyimide coverlay films, etc. onto the copper foil circuit pattern of the board, has high peel strength (adhesiveness) at room temperature, and has excellent peel strength (adhesive properties) for bonding semiconductor elements on the board. It will be able to withstand the solder bath when mounting. In addition, the method for manufacturing the adhesive composition of the present invention involves classifying phenol resin, butyral resin, epoxy resin, and two types of NBR, dissolving each class using a suitable solvent, and then mixing both liquids. As a result, precipitation of components does not occur during the manufacturing process, and the melting process can be carried out simultaneously for each section, making it possible to significantly shorten the dissolving process time.

Next, examples will be described together with comparative examples.

[Examples 1 to 7, Comparative Examples 1 to 8] 100 parts of phenol resin (manufactured by Showa Kobunshi Co., Ltd., BLS-362, concentration 60%), butyral resin (manufactured by Block Chemical Co., Ltd.,
75 parts of S-LEC BX-1) and 30 parts of epoxy resin (Epicoat 1001, manufactured by Yuka Shell Co., Ltd.) were added to IPA/MEK.
A mixed base resin having a solid content of 20% was prepared by dissolving it in a mixed organic solvent of =1/1 (weight ratio). On the other hand, using the various NBRs shown in Table 1 below in the proportions shown in the same table, NBR
A 20% MEK solution of BR was prepared. An adhesive composition was obtained by uniformly mixing a 20% MEK solution of 20 NBR and the above mixed base resin using a disper.

(Margins below) Using the actual height measurements and comparative height measurements obtained in this way, coating was applied to a 25 μm thick polyimide film (manufactured by Toshi DuPont, Kapton) so that the thickness after drying would be 30 μm. and dried at 120'C for 10 minutes. Next, an electrolytic copper foil with a thickness of 35 μm was superimposed on the adhesive-coated surface of the polyimide film, and heated at 170 °C and 30 kg/c.
After hot-pressing at a pressure of rA for 5 minutes to release the pressure, after-curing was performed at 150° C. for 30 minutes to produce a flexible copper foil laminated film.

Then, this flexible copper foil laminated film was heated at 20°C and 16°C.
After being left in 0% humidity for 24 hours or more, the peel strength, soldering heat resistance, and degree of curling of the copper foil were measured and evaluated, and the results are shown in Table 2 below. In addition, the compatibility stability of the formulations of the above adhesive compositions is also shown in Table 2 below. The peel strength, solder heat resistance, degree of curling, and compatibility stability of the blends of the copper foil were measured as follows.

(Peeling strength of copper foil) Using a Tensilon machine (manufactured by Toyo Side Cover Co., Ltd., UTM5), 25
The measurement was performed at a temperature of 50 mm/akin at a tensile rate of 50 mm/akin.

(Solder Heat Resistance) The flexible copper foil laminated film was cut into test pieces of 25 mm x 25 am, immersed in a solder bath adjusted to each temperature for 10 seconds, the test pieces were pulled out, and then cooled to room temperature. The occurrence of swelling, peeling, etc. on the test piece was visually confirmed, and the maximum temperature at which the above conditions occurred was determined and displayed.

(Degree of curl) Flexible copper foil laminate film was cut into 250 mm x 250 m test pieces and left on a horizontal surface in an environment of 60% humidity at 20°C for 24 hours. Items that cannot be completed are indicated as ○.

(Compatibility stability of formulations) Approximately 400 g of each adhesive composition was
After uniformly mixing and stirring for 15 minutes at 00rprrI, the mixture was sealed and left at 20°C for one week. Then, cases with no abnormalities were expressed as ○, and cases where the mixture was separated were expressed as ×.

(Left below) From the results in Table 2 above, two types of NB were added to the mixed base resin.
Examples in which R is blended at a specific blending ratio have all the characteristics,
Among these, it can be seen that it has excellent adhesive properties and soldering heat resistance.

Claims (7)

[Claims] (1) Contains the following components (A) to (E), and contains (A) to (C)
) The blending amount of component (D) is 1 per 100 parts by weight of component
0 to 80 parts by weight, and the amount of component (E) is set to be 10 to 80 parts by weight. (A) Phenol resin. (B) Butyral resin. (C) Epoxy resin. (D) Non-carboxylated acrylonitrile-butadiene copolymer solid at 25°C. (E) Carboxylated acrylonitrile-butadiene copolymer solid at 25°C. (2) Solution A obtained by dissolving the following components (A) to (C)
and a solution B obtained by dissolving the following components (D) and (E). (A) Phenol resin. (B) Butyral resin. (C) Epoxy resin. (D) Non-carboxylated acrylonitrile-butadiene copolymer solid at 25°C. (E) Carboxylated acrylonitrile-butadiene copolymer solid at 25°C. (3) The uncarboxylated acrylonitrile-butadiene copolymer of component (D) has an acrylonitrile content of 27
~45% by weight, and Mooney viscosity is JIS-K-63
The adhesive composition according to claim 1 or 2, which has a ML of 50 ML1+4 or more at 100° C. according to the 00 test method. (4) The carboxylated acrylonitrile copolymer of component (E) has an acrylonitrile content of 20 to 40% by weight.
The adhesive composition according to any one of claims (1) to (3), wherein the carboxyl group content is 1 to 10% by weight. (5) A step of homogeneously dissolving the following components (A) to (C) in an organic solvent whose main component is an alcohol-based organic solvent, and uniformly dissolving the following components (D) and (E) in a ketone-based organic solvent. 1. A method for producing an adhesive composition, comprising a step of uniformly mixing both liquids. (A) Phenol resin. (B) Butyral resin. (C) Epoxy resin. (D) Non-carboxylated acrylonitrile-butadiene copolymer solid at 25°C. (E) Carboxylated acrylonitrile-butadiene copolymer solid at 25°C. (6) The uncarboxylated acrylonitrile-butadiene copolymer of component (D) has an acrylonitrile content of 27
~45% by weight, and Mooney viscosity is JIS-K-63
6. The method for producing an adhesive composition according to claim 5, wherein the adhesive composition has an adhesive composition of 50 ML1+4 or more at 100° C. according to the 00 test method. (7) The method for producing an adhesive composition according to claim (4) or (5), wherein the carboxylated acrylonitrile copolymer as component (E) has an acrylonitrile content of 20 to 40% by weight.