JPS5917670B2 - laminate board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a laminate that has good adhesive strength and excellent flame retardancy, heat resistance, and various electrical properties, and is particularly suitable for rigid printed wiring boards. It is related to.

Conventionally, various types of laminates have been known. For example, copper-clad laminates include phenolic resin, epoxy resin,
A laminated plate made of polyester resin or the like and a reinforcing material with copper foil bonded and integrated has been put into practical use.

However, these copper-clad laminates have the disadvantage of poor flame retardancy and heat resistance, and when placed in a high temperature atmosphere of 150°C or higher, electrical properties such as dielectric constant deteriorate significantly. For this reason, attempts have been made to use phenolic resins mixed with flame retardants in order to impart flame retardancy to the laminates, but these flame retardants have the disadvantage of impairing electrical properties. On the other hand, laminates obtained by impregnating glass cloth with silicone varnish for lamination and molding them have excellent flame retardancy, heat resistance, and various electrical properties at high temperatures, so this silicone glass laminate and A product made by integrating copper foil is known, but this product has the drawback of weak adhesive strength.

This invention (') aims to provide a laminate that eliminates the conventional drawbacks as described above, and this invention (') molar ratio (R/
/Si) is applied or impregnated with an organopolysiloxane resin of 1.0 to 1.7, and a metal foil and an inorganic fiber prepreg are directly connected to an alkenyl group-containing diorganopolysiloxane and a silicon atom. It is formed by laminating and integrating an organopolysiloxane composition consisting of an organohydrodiene polysiloxane having hydrogen atoms, an inorganic filler, and platinum or a platinum compound.

Next, to explain the present invention in more detail, the prepreg used in the present invention is made by impregnating or coating an inorganic fiber with an organopolysiloxane resin. Cloth, glass mat, glass yarn, asbestos cloth, etc. can be used, and in the present invention, it is particularly preferable to use glass cloth.

Further, as mentioned above, the organopolysiloxane resin is required to have a YVSi ratio (mole ratio) of 1.0 to 1.7, and if the molar ratio is less than 1.0, the organopolysiloxane resin The heat curing properties of
This has the disadvantage that the resulting prepreg is too hard and brittle, while a molar ratio greater than 1.7 slows down the curing rate of the organopolysiloxane resin and the resulting prepreg has poor mechanical strength at high temperatures. There is a disadvantage of being inferior.

Note that this organopolysiloxane resin (1) preferably contains at least 0.25% by weight of hydroxyl groups directly bonded to silicon atoms, taking into account bonding conditions with inorganic fibers.

Therefore, the constituent units of such an organopolysiloxane resin can be selected from diorganosiloxane units represented by (', RSiOl, diorganosiloxane units represented by R2SiO, and triorganosiloxane units represented by R3SiOO5). , R//Si
As long as the ratio (molar ratio) of (1) is 1.0 to 1.7, there are no particular restrictions on the types and blending ratios of (1).

Suitable organic groups R directly bonded to the silicon atom include alkyl groups such as methyl, ethyl and propyl groups, aryl groups such as phenyl, alkenyl groups such as vinyl and allyl groups, and even methoxy groups. , an alkoxy group such as an ethoxy group or a propoxy group.
This organopolysiloxane resin can be produced by a conventionally known method, for example by (co)hydrolyzing the corresponding organochlorosilanes or (or alkoxysilanes) and condensing them if necessary. In order to obtain a prepreg by coating or impregnating the above-mentioned inorganic fiber with an organopolysiloxane resin, for example, the above-mentioned organopolysiloxane resin is coated with hum silica, precipitated silica, quartz powder, etc. A curing agent such as an inorganic optical filler, an organic peroxide, a metal salt of an organic acid, an organic amine (or an organic acid salt of this organic amine), and an organic solvent such as benzene, toluene, or xylene are combined, and these three Prepare a coating solution by blending it with a roll or a ball mill until it becomes completely uniform, and then apply it to or impregnate the inorganic fiber.
Precure at an appropriate temperature (about 130°C), then heat and pressurize at a temperature of 150 to 20°C and a pressure of 5 to 100 kg/~.

Next, the organopolysiloxane composition used in the present invention (as described above) includes an alkenyl group-containing diorganopolysiloxane, an organohydrodiene polysiloxane having a hydrogen atom directly bonded to a silicon atom, and an inorganic optical filler. and platinum or a platinum compound, and as the alkenyl group-containing diorganopolysiloxane (1), various types can be used; mol% is alkenyl group, and 2
and a diorganopolysiloxane having a viscosity at 5°C of 1,000,000 senna stokes or more,
0.01 to 15 mol% of all organic groups directly bonded to silicon atoms
is an alkenyl group, and the viscosity at 25°C is 10
Preference is given to using organopolysiloxane mixtures consisting of diorganopolysiloxanes of less than 0,000 centistokes.

R1 and R3 in the above general formula (1) or () (
is a monovalent hydrocarbon group such as a methyl group, ethyl group, propyl group, vinyl group, or phenyl group, or a substituted monovalent hydrocarbon group in which part or all of the hydrogen atoms of these groups are substituted with a halogen atom, etc. R2 and R4 ( are groups selected from hydroxyl groups or monovalent hydrocarbon groups such as (1 methyl group, ethyl group, propyl group, vinyl group, allyl group, m and n (each is a positive integer.

Diorganopolysiloxane represented by the above general formula (1) (0.0005% of all organic groups directly bonded to silicon atoms)
It is essential that ~5 mol%, preferably 0.005~3 mol%, is an alkenyl group such as a vinyl group;
centistokes or more, preferably 3,000,000 centistokes or more
It is preferably in the range of ~8,000,000 centistokes.

This diorganopolysiloxane has a ratio of alkenyl groups to all organic groups bonded to silicon atoms of 0.0005.
If it is less than 5 mol%, the crosslinking density will be low and the resulting cured film will have poor mechanical strength.If it is more than 5 mol%, the adhesiveness will be reduced, and the resulting film will have too high a crosslinking density, resulting in poor flexibility. It becomes hard and brittle, inferior in quality. In addition, organopolysiloxane (
0.01 to 15 mol%, preferably 10.1 to 5 mol% of all organic groups directly bonded to silicon atoms are alkenyl groups such as vinyl groups, and the viscosity at 25°C is 100%.
,000 centistokes or less, preferably 100 to 5
The alkenyl group content is preferably 0,000 centistokes, and if the alkenyl group content is outside the above range, the purpose cannot be achieved for the same reason as above.

The mixing ratio of the organopolysiloxane described above is represented by the general formula (1), and the diorganopolysiloxane is 95 to 5
0% by weight, preferably 90 to 60% by weight, 5 to 50% of the diorganopolysiloxane represented by general formula (1)
% by weight, preferably from 10 to 40% by weight, but if the proportion of the diorganopolysiloxane represented by general formula (1) exceeds 95% by weight, the composition The wettability to the foil becomes poor, and the adhesion property decreases; on the other hand, if it exceeds 50% by weight, the wettability to the metal foil (1) improves, but the mechanical strength, especially the cohesive strength, decreases. Cohesive failure occurs at the adhesive interface, resulting in significantly poor adhesive strength.

Furthermore, the organohydrodiene polysiloxane in the organosopolysiloxane composition used in the present invention is
It is preferable that one molecule has at least two hydrogen atoms directly bonded to a silicon atom. Any organohydrodiene polysiloxane having a , branched or cyclic structure can be used.

The amount of organohydrodiene polysiloxane used is 1.2 to 6 hydrogen atoms directly bonded to a silicon atom per alkenyl group directly bonded to a silicon atom in the alkenyl group-containing diorganopolysiloxane, preferably 1.2 to 6 hydrogen atoms directly bonded to a silicon atom. 1.
It is said that the amount is necessary to give 4 to 3 pieces, but this (is 1 or 2
(The J composition does not cure well, resulting in a decrease in mechanical strength and extremely poor adhesion. Also, when the number exceeds 6, good curing cannot be achieved and the adhesion resulting in a decrease in power.

The viscosity of this organohydrodiene polysiloxane (''
There is no need to limit it in particular as long as it has fluidity, but when considering workability etc. (viscosity at 25℃ is 10
,000 centistokes or less.

Specific examples of such organohydrodiene polysiloxanes include the following.

\\v Tools j/VV&V/4 Next, concrete examples of inorganic optical fillers include reinforcing optical fillers such as dry silica, wet silica, and silane-treated silica whose surface is treated with trichloromethylsilane. agent,
Examples include fillers that can impart flame retardancy such as zirconium silicate, glass fiber powder, aluminum silicate, diatomaceous earth, zinc oxide, and zinc carbonate. It is preferable to use dry silica of about 300 m2/9, and two or more of these may be used in combination.

The amount of this inorganic filler used is 10 to 200 parts by weight based on 100 parts by weight of the above-mentioned alkenyl group-containing diorganopolysiloxane and organohydrodiene polysiloxane.
Parts by weight, preferably in the range of 20 to 100 parts by weight. If it is less than 10 parts by weight, the composition will have poor adhesive properties, and the mechanical strength of the cured product will decrease.
This is because if the amount exceeds 0 parts by weight, the adhesiveness will be poor.

Furthermore, the platinum or platinum compound may be one that has been conventionally known as a catalyst for the addition reaction between an alkenyl group-containing organopolysiloxane and an organohydrodiene polysiloxane, such as chloroplatinic acid, alcohol-modified chloroplatinic acid, Examples include complexes of chloroplatinic acid and olefin, solid platinum supported on carriers such as platinum black, alumina, and silica.

The amount used is a catalytic amount, that is, usually 50% platinum based on the alkenyl group-containing diorganopolysiloxane.
If it is set to ~40 ppm, it is equivalent to light, but it is desirable to increase or decrease it as appropriate depending on the desired curing speed. The above-mentioned composition is prepared by mixing each of the above-mentioned components with a roll kneader, pen shell mixer,
It is manufactured by kneading with a Banbury mixer or the like, but there are no particular restrictions on the order of mixing these ingredients.

However, since the composition may harden due to the action of the platinum compound during heating and kneading, it is advantageous to add the platinum compound last. At this time, if necessary, a conventionally known platinum compound activity inhibitor such as an organic phosphorus compound, a halocarbon, an acetylene compound, a sulfoxide compound, etc. may be added at the same time.
Metal foils that can be used in the present invention include:
Examples include copper foil such as electrolytic copper foil and rolled copper foil, and aluminum foil.

In obtaining the laminate of the present invention (1), for example, prepreg of metal foil and inorganic fibers is prepared using the above-mentioned organopolymer.
A method of integrating the siloxane composition by heating and applying pressure (1) Place a glass cloth on the metal foil, and impregnate or apply the organopolysiloxane composition (diluted with a solvent if necessary) to the glass cloth. After removing the solvent at room temperature to 50℃, inorganic fiber prepreg was layered on glass cloth, and the temperature was 180℃ and the pressure was 80kg/CTIL.
Precure may be carried out for about 60 minutes at a nearby temperature, and if necessary, postcure may be carried out at 200° C. for about 2 to 4 hours to ensure sufficient curing.

The organic solvent used for diluting the organopolysiloxane composition mentioned above may include aliphatic or aromatic hydrocarbon solvents such as toluene, xylene, and mineral turpentine; A mixture of hydrophilic organic solvents such as ethanol, isopropyl alcohol, ethyl acetate, methyl ethyl ketone, acetone, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether can also be used. (1) In particular, it improves wetting to metals and provides stable and uniform adhesion.

Furthermore, the surface of the metal foil may be pretreated with a conventionally known primer, which can further improve adhesion. Examples include those that have a coupling effect mainly based on .

The laminate of the present invention obtained as described above (1) has much superior adhesive strength (2 to 3 times) compared to the conventionally known laminate made of silicone glass laminate and copper foil. This adhesive strength is 1,5009/C at room temperature.
ln or higher, and no decrease in adhesive strength was observed even after being left in an atmosphere of 50°C and 90% RH for 2 months, or for 2 months in an atmosphere of 105°C. It also has excellent resistance to industrially used etching solutions (5% sodium hydroxide solution).

For example, printed wiring, which is made by printing desired wiring on a copper-clad silicone glass laminate using a known method and removing unnecessary copper foil by etching, has excellent adhesive strength, heat resistance, electrical properties, and flame retardancy. This product has excellent heat resistance (can withstand heating at 300°C for 30 minutes in solder welding of printed wiring), and can be used for continuous solder welding. Next, an example of the present invention will be given, and the organopolysiloxane composition (adhesive) used in this example was prepared as follows.

Example Preparation of organopolysiloxane composition (adhesive) The viscosity is 4,000,000 centistokes, 0.004 mol% of all organic groups directly bonded to silicon atoms are vinyl groups, and both ends of the molecular chain are vinyl groups. vinyl group-containing dimethylpolysiloxane capped with dimethylvinylsilyl groups 60.
09, and the viscosity is 10,000 centistokes,
Vinyl group-containing dimethylpolysiloxane 40, in which 0.174 mol% of all organic groups directly bonded to silicon atoms are vinyl groups, and both ends of the molecular chain are blocked with dimethylvinylsilyl groups.
09 and added dry silica fine powder (trade name Aerosil A-300; Nippon Aerosil Co., Ltd.) 5009 and dimethyldimethoxysilane 109, and heated to 180°C while mixing in a secondary oven for about 3 hours. After kneading at the same temperature, the mixture was cooled and further kneaded using a diroller, and the resulting kneaded product was then dissolved in a mixed solvent consisting of xylene 15009 and isopropyl alcohol 8509.

After adding chloroplatinic acid in an amount of 12 ppm based on the weight of platinum, methylhydrodienepolysiloxane (the amount of hydrogen gas generated in the presence of potassium hydroxide (amount of hydrogen gas generated in the presence of potassium hydroxide) shown by the molecular formula: atmospheric pressure)
, when the amount of hydrogen atoms per vinyl group in the stock solution is 1.
Adjustment was made by adding an amount of 5.

Test 1 A glass cloth (WE22, manufactured by Nitto Boseki Co., Ltd.) was layered on an electrolytic copper foil with a thickness of 35 μm, and the glass cloth was impregnated with the organopolysiloxane composition prepared above. The solvent was removed by drying for a minute.

Next, apply laminating varnish (K
R26O7, Shin-Etsu Chemical Co., Ltd. glass cloth (
A stack of 5 prepregs obtained by impregnating WEl8GTl (manufactured by Nittobo Co., Ltd.) was placed and heated at 180°C and 50°C.
kg/d for 60 minutes, and after cooling, the press was released to obtain a laminate.

This material had a thickness of 0.75 mm.Test 2 Five sheets of prepreg made from silicone lamination varnish (KR26O5Bs manufactured by Shin-Etsu Chemical Co., Ltd.) and glass cloth (WEL8Gl manufactured by Nittobo Co., Ltd.) and copper foil were used. A sheet of glass cloth (WE22, manufactured by Nitto Boseki Co., Ltd.) was stacked, the adhesive prepared above was applied on top of the glass cloth, air-dried at room temperature, and the sheets were stacked and pressed at 180°C and 100kg/CTli for 60 hours. A laminate was obtained.

Test 3 Three sheets of silicone lamination prepreg (KMC31O, manufactured by Shin-Etsu Chemical Co., Ltd.) and glass cloth (WE22
, manufactured by Nittobo Co., Ltd.), applied the adhesive prepared above, dried at 50°C for about 10 minutes, stacked them together, and heated them at 180°C at 100kg/CTi. A laminate was obtained by pressing for 30 minutes under the following conditions.

When the adhesive strength, through-layer withstand voltage, volume resistivity, and heat resistance of the laminates prepared in Tests 1 to 3 were examined, the results shown in the table below were obtained.

Claims (1)

[Claims] 1. A silicon atom (Si) and an organic group (R) directly connected to it
An inorganic fiber prepreg coated with or impregnated with an organopolysiloxane resin having a molar ratio (R/Si) of 1.0 to 1.7 and a metal foil are mixed with alkenyl group-containing diorganopolysiloxane, silicon A laminate 2 formed by laminating and integrating an organopolysiloxane composition comprising an organohydrodiene polysiloxane having a hydrogen atom directly connected to an elementary atom, an inorganic filler, and platinum or a platinum compound.The alkenyl group-containing diorganopolysiloxane is a) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R^1 represents a substituted or unsubstituted monovalent hydrocarbon group, and R^2 represents a hydroxyl group or a monovalent hydrocarbon group of the same or different type. , m represents a positive integer), 0.0005 to 5 mol% of all organic groups directly bonded to silicon atoms are alkenyl groups, and the viscosity at 25°C is 1.0
b) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R^3 is a substituted or unsubstituted monovalent hydrocarbon group, and R^4 is represents a hydroxyl group or a monovalent hydrocarbon group of the same or different kind, n represents a positive integer), and 0.01 to 15 mol% of all organic groups directly bonded to silicon atoms are alkenyl groups, and Viscosity at 25°C is 100,
The laminate according to claim 1, which is an organopolysiloxane mixture comprising a diorganopolysiloxane having a diorganopolysiloxane of less than 1,000 centistokes.