JP6156638B2 - Cyanate ester resin composition - Google Patents

Description

The present invention relates to a one-component cyanate ester resin composition having a storage stability (latency) and a thermosetting property in which a reaction starts at 200 ° C. or lower.

Cyanate ester resins have heat resistance and have been used for electronic substrates for a long time. However, since the cyanate ester resin used for the application is solid at room temperature and is used for injection molding, impregnation and the like, the cyanate ester resin composition does not need to start the reaction at 200 ° C. or less, and 200 Curing was performed at a high temperature of ℃ or higher. Further, it was not necessary to have storage stability such that it was liquid at 25 ° C. and the viscosity did not change. Conventionally, metal catalysts such as zinc naphthenate and phenol resins are also known as curing catalysts. However, when they are made into compositions, they cannot prevent thickening even if they are stored frozen at −20 ° C.

Table 2 of Patent Document 1 describes titanocene dichlorides classified as titanocene, and a comparison is made by DSC measurement regarding the presence or absence of addition of a metal catalyst. However, it is a conventionally known fact that the peak shifts to the low temperature side in the composition to which the metal catalyst is added as compared with the composition to which the metal catalyst is not added. Moreover, it is estimated that the hydroxyl group of the polyalkylene glycol described in Patent Document 1 does not react with the cyanate ester group, and the polyalkylene glycol is a plasticizer. It is thought that there is a deterioration in the physical properties of

Patent Document 2 discloses a metal catalyst having a specific structure classified as titanocene. However, verification by the type of ligand in titanocene has been made. However, the invention of Patent Document 2 substantially contains a solvent, and the storage stability and reactivity of the composition itself have not been verified.

Japanese National Patent Publication No. 11-501077 JP-A-9-157391

Conventionally, a one-component curable cyanate ester resin composition that is liquid at 25 ° C. and does not contain a solvent maintains storage stability with low viscosity and starts reactivity at 200 ° C. or lower. It was difficult.

As a result of intensive studies to achieve the above object, the present inventors have completed an invention relating to a cyanate ester resin composition having latency and storage stability.

The gist of the present invention will be described next. A first embodiment of the present invention is a one-component curable resin composition that includes the following components (A) and (B), is liquid at 25 ° C., and does not include a solvent.
(A) component: cyanate ester resin (B) component: at least one metallocene selected from the group consisting of metallocenes of chemical formula 2 and derivatives thereof

The second embodiment of the present invention is the curable resin composition according to the first embodiment that does not contain an epoxy resin.

The third embodiment of the present invention is the curable resin composition according to any one of the first and second embodiments which does not contain a curing agent or a curing catalyst in addition to the component (B).

The fourth embodiment of the present invention is the curable resin composition according to any one of the first to fourth embodiments, wherein the component (A) includes a cyanate ester resin having a bisphenol E-type skeleton.

The fifth embodiment of the present invention is an adhesive comprising the curable resin composition described in any of the first to fourth embodiments.

The one-component cyanate ester resin composition of the present invention maintains the storage stability while maintaining low physical properties while maintaining physical properties, and has a reaction initiation temperature of 200 ° C. or lower.

FIG. 1 shows the results of DSC measurement in Examples 1 and 2 and Comparative Examples 1 to 5.

Details of the present invention will be described below. The component (A) that can be used in the present invention is a cyanate ester resin. If it is liquid at 25 ° C., it can be used, and if it is difficult to recrystallize, it can be used. Cyanate ester resins that are solid at 25 ° C. need to be dissolved with a solvent or the like, are inferior in handleability, and are not suitable because the solvent cannot be volatilized by the method of laminating adherends because the solvent remains inside.

Specific examples of the cyanate ester resin include a bisphenol E type cyanate ester resin represented by Formula 1, but the cyanate ester resin is not limited thereto. Cyanate ester resins such as biphenyl type, novolak phenol type, and bisphenol A type are solid at 25 ° C, but can be used if they are dissolved in a cyanate ester resin that is liquid at 25 ° C and liquid at 25 ° C. it can.

Specific examples of the component (A) include Cyanate LeCy, PT-15, PT30, PT-60 manufactured by Lonza, L-10 manufactured by Huntsman, XU366, XU371, XU378, etc., manufactured by Mitsubishi Gas Chemical Co., Ltd. Examples include CA200, but are not limited thereto.

The component (B) that can be used in the present invention is a metallocene represented by the general formula 2 and derivatives thereof. R in the general formula is an independent halogen or organic group, and M is a metal of Group 4A of the periodic table excluding titanium. Considering the low price, availability, and catalyst stability, the metal is preferably zirconium or hafnium.

Specific examples of the component (B) include, but are not limited to, zirconocene dichloride, zirconocene chloride hydride, 1,1-dibutylzirconocene dichloride, decamethylzirconocene dichloride, zirconocene dimethyl, and hafnocene dichloride. .

(B) A component may be used individually or in mixture of 2 or more types. (A) It is preferable to add 0.01-1.0 mass part of (B) component with respect to 100 mass parts of component. When the amount is more than 0.01 parts by mass, heat curability can be maintained, and when the amount is less than 1.0 parts by mass, thickening can be suppressed. As a heating method, it can harden | cure using general methods, such as ventilation of a hot air by a hot air drying furnace.

The cyanate ester resin composition of the present invention preferably contains no curing agent or curing catalyst other than the epoxy resin or component (B). The epoxy resin cannot be cured using the component (B) as a curing agent. Therefore, if an epoxy resin is simply added to the cyanate ester resin composition of the present invention, the epoxy resin does not participate in curing and corresponds to a mere plasticizer. As a result, the physical properties of the cured product are greatly changed. Specifically, the glass transition point is lowered, the storage elastic modulus is lowered, and the tensile shear bond strength is lowered. In the worst case, the curability is deteriorated, and the uncured portion is partially generated in the cured product. The component (A) is hard to be cured by an amine-based curing agent exemplified as an epoxy resin curing agent, and it is necessary to add a large amount of an amine-based curing agent in order to cure the component. Therefore, it has thixotropy and is unlikely to have an optimal property, and even if it can be cured, it is difficult to express optimal physical properties. Moreover, when a phenol resin is added as a curing agent, there is no storage stability even if it is stored at -20 ° C. Therefore, in order to express optimal properties and physical characteristics, it is preferable not to contain a curing agent or a curing catalyst in addition to the component (B).

It is preferable not to add a solvent to the cyanate ester resin composition of the present invention. When it is used by adhering to the purpose of bonding or in the gap, the solvent may remain in the composition and foam. When a solvent is not added, it can be used for bonding and sealing.

The present invention can be used in various applications such as electrical applications used for assembling electric / electronic parts and in-vehicle applications that require heat resistance.

In the cyanate ester resin composition of the present invention, within the range not impairing the effects of the present invention, colorants such as pigments and dyes, inorganic powders such as metal powder, calcium carbonate, talc, silica, alumina, aluminum hydroxide, An appropriate amount of additives such as an organic filler, a flame retardant, a plasticizer, an antioxidant, an antifoaming agent, a leveling agent, a rheology control agent, and a coupling agent may be blended.

EXAMPLES Next, although an Example is given and this invention is demonstrated further in detail, this invention is not limited only to these Examples.

[Examples 1 and 2 and Comparative Examples 1 to 5]
The following components were prepared to prepare a cyanate ester resin composition. (Hereinafter, the cyanate ester resin composition is simply abbreviated as a composition.)

(A) Component: Cyanate ester resin / bisphenol E type cyanate ester (Cyanate LeCy; manufactured by Lonza)
(B) component:
・ Catalyst 1: Zirconocene dichloride (reagent)
・ Catalyst 2: Hafnocene dichloride (reagent)
Component (B ′): Metal catalyst / catalyst other than component (B) 3: Bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole-1) -Yl) -phenyl) titanium (IRGACURE784 manufactured by BASF)
Catalyst 4: titanocene dichloride (reagent)
Catalyst 5: Titanocene bis trifluoromethane sulfonate (reagent)
Catalyst 6: Ferrocene (reagent)
Catalyst 7: Zinc naphthenate (reagent)

The component (A) is weighed in a container, and then the component (B) is weighed and put into the container. The mixture was stirred for 1 hour with a stirrer. Detailed preparation amounts follow Table 1, and all numerical values are expressed in parts by mass.

The composition was subjected to viscosity measurement, storage stability confirmation, tensile shear bond strength measurement, DMA measurement, and TMA measurement. Table 2 shows the results of viscosity measurement and storage stability confirmation, and Table 3 shows the results of tensile shear bond strength, DMA measurement, and TMA measurement.

[Viscosity measurement]
The viscosity immediately after adjusting the composition is measured according to the following specifications, and is defined as “initial viscosity (mPa · s)”. The remaining composition is stored in a container.
Specifications Viscometer: VISCOMETER TV-33 manufactured by Toki Sangyo Co., Ltd.
Cone: 1 ° 34 '× R24
Measurement conditions: 20 rpm / 3 min

[Confirm storage stability]
The composition is stored in a dark place at 25 ° C., extracted after 7 days and 14 days, and the viscosity is measured by the same method as the above viscosity measurement. The respective viscosities are referred to as “viscosity after 7 days (mPa · s)” and “viscosity after 14 days (mPa · s)”. It is defined as “change rate (%)” of the initial viscosity and the viscosity after 14 days. From the viewpoint of handleability of the composition, the initial viscosity is preferably 100 mPa · s or less, and from the viewpoint of storage stability, the rate of change is preferably 100% or less. When the upper limit of measurement of the viscometer is exceeded, if the rate of change cannot be calculated along with it, it is described as “not measurable”.

[Measurement of tensile shear bond strength]
An SPCC-SD adherend of width 25 mm × length 10 mm × thickness 1.6 mm was bonded and fixed at 25 mm × 10 mm, and then heated at 150 ° C. × 1 h + 200 ° C. × 1 h as a curing condition to prepare the composition. Cure to create a test piece. Both ends of the test piece are fixed, pulled at a pulling speed of 50 mm / min, and “adhesive strength (MPa)” is measured from the maximum strength. When used as an adhesive, it is preferably 10 MPa or more for fixing the adherend.

[DSC measurement (differential scanning calorimetry)]
Using an SSC5200 manufactured by Seiko Instruments Inc., the composition is set in an uncured state, measured from 25 to 300 ° C. at a heating rate of 5 ° C./min, and the peak top of DSC (μW) The temperature is defined as “reaction temperature (° C.)”. The reaction temperature of the composition is preferably 100 to 200 ° C. in consideration of line tact.

[DMA measurement (dynamic viscoelasticity measurement)]
The composition is sandwiched between two polytetrafluoroethylene plates with a clearance of 1.0 mm. Thereafter, the cured product is prepared by heating at 150 ° C. × 1 h + 200 ° C. × 1 h as curing conditions. The cured product was cut into a size of 10 mm × 50 mm, and measured with a DMS6100 manufactured by Seiko Instruments Inc. in a tensile mode with a temperature range of 25 to 350 ° C., 5 ° C./min, and a frequency of 1 Hz. Two measurements are made on the same cured product. In the second measurement, “storage elastic modulus (MPa) at 25 ° C.” is E ′, “peak top temperature of loss elastic modulus (° C.)” is E ”, and“ tan δ peak top temperature (° C.) ”is This is indicated as tan δ. E ″ or tan δ is considered to correspond to the glass transition point in the DMA measurement. From the viewpoint of heat resistance, the cured product is hard, and E ′ is preferably 5.0 or less. From the viewpoint of heat resistance. The temperature at which the cured product softens needs to be high, and E ″ is preferably 250 ° C. or higher, or tan δ is preferably 250 ° C. or higher.

[TMA measurement (thermal mechanical analysis measurement)]
The composition is poured into a cylindrical shape having a diameter of 5 mm and heated at 150 ° C. × 1 h + 200 ° C. × 1 h as curing conditions to prepare a cured product. The sample was cut to a length of 10 mm and measured with a TMA / SS6000 manufactured by Seiko Instruments Inc. in a tension mode of 25 to 380 ° C., 5 ° C./min, and a frequency of 1 Hz. Two measurements are made on the same cured product. In the second measurement, “linear expansion coefficient in the temperature region lower than the glass transition point (ppm / ° C.)” is α1, and “linear expansion coefficient in the temperature region higher than the glass transition point (ppm / ° C.)” is α2. The glass transition point is denoted as Tg. Since less heat expansion has less influence on the adherend, α1 is preferably 70 ppm or less and α2 is preferably 200 ppm or less. In addition, from the viewpoint of heat resistance, the temperature at which the cured product softens needs to be high, and Tg is preferably 250 ° C. or higher.

Comparing the initial viscosities of Examples 1 and 2 and Comparative Example 5, it can be seen that the composition using catalyst 7 is thickened. That is, as can be seen from the result of DSC measurement in FIG. 1, it is considered that Comparative Example 5 has a low calorific value of the DSC peak, and the reaction has already started at the time of measurement. In Examples 1 and 2 and Comparative Examples 1 to 4, the initial viscosity is stable. However, Comparative Examples 2 to 4 are thickened when left at 25 ° C. after 7 days. In Comparative Example 4, it is considered that the reaction temperature is too low from the result of DSC measurement in FIG. 1 and the reaction is progressing because there is no potential, and the viscosity becomes so high that the viscosity cannot be measured. Yes.

Although Examples 1 and 2 and Comparative Examples 1 to 3 have a low rate of change and good storage stability, there is a difference in the reaction temperature in DSC. That is, the reaction temperature of Comparative Examples 1 to 3 is higher than 200 ° C., and Examples 1 and 2 have a reaction temperature of 200 ° C. or lower. Even if the rate of change is low, the higher the reaction temperature, the higher the temperature or the longer it is necessary to heat. Examples 1 and 2 have good storage stability and can be cured at a low temperature of 200 ° C. or lower.

The conventional one-component cyanate ester resin composition is poor in storage stability and has a high curing temperature. The present invention improves these problems and has a low initial viscosity and good handling. In addition, physical properties such as glass transition point are also exhibited as usual. Accordingly, the present invention can be used for adhesives and sealants, which have been rarely used in the past, and the range of use of cyanate ester resins can be expanded.

1: DSC peak top in Example 1: DSC peak top in Example 2: DSC peak top in Comparative Example 1: DSC peak top in Comparative Example 2: DSC peak top in Comparative Example 3 DSC peak top in Comparative Example 3 6: DSC peak top in Comparative Example 4 7: DSC peak top in Comparative Example 5

Claims (5)

A one-component curable resin composition containing a component (A) and a component (B), which is liquid at 25 ° C. and does not contain a solvent.
(A) Component: Cyanate ester resin (B) Component: Metallocene selected from the group consisting of metallocenes of general formula and derivatives thereof
(R in the general formula is an independent halogen or organic group, and M is a metal of Group 4A of the periodic table excluding titanium.) The curable resin composition of Claim 1 which does not contain an epoxy resin. The curable resin composition according to claim 1, which contains no curing agent or curing catalyst other than the component (B). The curable resin composition according to any one of claims 1 to 3, wherein the component (A) includes a cyanate ester resin having a bisphenol E-type skeleton. An adhesive comprising the curable resin composition according to any one of claims 1 to 4.