JPS6028665B2 - Method for producing thermosetting organopolysiloxane composite material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a thermosetting organopolysiloxane composite material, particularly a sheet-like molding material.

Molded products made from silicone molding materials have superior heat resistance, flame resistance, moisture resistance, and electrical properties compared to molded products made from general synthetic resin molding materials. It is widely applied in the electrical industry, high temperature industry, etc.

Depending on the molding method, this type of silicone resin molding material can be molded by compression molding, transfer molding, or injection molding, or it can be molded by compression molding or lamination molding. It is roughly divided into types that can only be molded using molding methods.

The former type of silicone resin molding material is made by adding short glass fibers with a fiber length of 1 side or less to a composition consisting of a silicone resin and an inorganic filler, if necessary, and then processing this together with a curing catalyst, lubricant, pigment, etc. in a kneader. ,. It is obtained by uniformly kneading it under heating and melting using a mill, Banbury mixer, high-speed stirrer, etc., then cooling it and, if necessary, crushing it with a crusher such as a hammer mill. Although it has the advantage of being easy to handle and allowing a variety of molding methods to be selected as mentioned above, on the other hand, the mechanical strength of the resulting molded product, especially its impact strength and bending strength, is low, making its use difficult. The problem is that it is limited to fields that are not subject to too much external force. The latter type of silicone resin molding material includes a silicone resin, an inorganic filler, a curing catalyst and, if necessary, a lubricant. A composition containing pigments and the like is dissolved in an organic solvent, applied to or impregnated with a long glass fiber, heated to remove the solvent, and laminated as it is, or formed into a long glass fiber. The fibers and the like are suitably cut or crushed into a size of 3 to 6 ribs and compression molded. The molded products obtained from this type of molding material have significantly improved impact strength and bending strength compared to the molded products obtained from the former molding material, and are suitable for applications where high mechanical strength is required. 300qo~400℃
It can be used at temperatures as high as
It has the feature of heat shock resistance). However, this product has the disadvantage that its molding is limited to compression molding or lamination molding, and the glass fiber length is 3 to 6.
Ribs for compression molding have a low bulk specific gravity and a large bulky shape, so it takes a long time to fill the mold and has a "fat roll" that is quite large compared to the volume of the final molded product. A mold is required and therefore the mold must be tall, which not only increases the cost of the mold, but also increases the weight of the mold and makes it difficult to handle. Such a tall mold has a disadvantage in that the temperature distribution is large and it is difficult to obtain a proper molded product. On the other hand, when using a normal-sized mold, it is necessary to fill the material by hand and wait until the resin melts and the basket becomes smaller before attaching the upper mold. During filling, the first filled resin may be heated and turn into a gel, or the flow may become poor.
The disadvantage is that it is difficult to obtain a good molded product. Furthermore, since this type of product requires coating and uses organic solvents or water during impregnation, it is necessary to remove them before molding.Especially in the case of organic solvents, it is necessary to remove them from the viewpoint of pollution prevention and environmental hygiene. They are subject to various restrictions, and their removal requires the use of a large amount of thermal energy, which is economically disadvantageous.

The present invention aims to provide a method for producing a new and improved thermosetting organopolysiloxane composite material that solves the various problems described above. It is characterized by superimposing 90 to 1 part by weight of glass fibers having a fiber length of 1 to 10 m on a mixed powder of 1 part by weight and a catalytic amount of a curing catalyst, melting the resin, and then cooling it. According to this method, it is not necessary to use the '1' solvent at all, so there is no pollution and hygiene problem, and no thermal energy is required to remove it, so it is extremely economical.

{2nd) It has the following effects: Stretching is small and workability during molding is very good; and 3) The resulting molded product has excellent mechanical strength and heat shock resistance. The present invention will be explained in more detail below.

First, the organopolysiloxane resin used in the method of the present invention has, for example, an average compositional formula of RnSi○ (where R represents a monovalent hydrocarbon group such as an alkyl group, an alkenyl group, or an aryl group, and n is 1 .0 to 1.6), contain a small amount of condensable functional groups such as hydroxyl groups and alkoxy groups directly connected to elementary atoms, and are organic acid salts of metals or amine compounds. The condensation curing type cures by the action of a catalyst, the vinyl polymerization type cures by an organic peroxide, the catalytic action of platinum or a platinum compound, and the catalytic action of platinum or a platinum compound. Addition type, which cross-links and cures through addition reaction.
In addition, the mechanism of the crosslinking reaction is not particularly limited, and any type of thermosetting organopolysiloxane resin can be used.

The above-mentioned condensation-curing organopolysiloxane resin is of the type that cures by dehydration condensation of hydroxyl groups, from the viewpoint of quickly curing and obtaining molded products with excellent mechanical strength. The content of hydroxyl groups bonded to elementary atoms is often 0.25% by weight or more, and if the amount of hydroxyl groups is less than 0.25%, not only will the curing speed during molding decrease, but also sufficient curing will occur. is not obtained.

This organopolysiloxane resin may contain an alkoxy group such as a methoxy group, an ethoxy group, or a propoxy group. Furthermore, the vinyl polymerizable organopolysiloxane resin has a molar ratio of vinyl groups/poppy atoms to 0.02 to 0.0.
7 is better.

Furthermore, the addition-type organopolysiloxane resin may be used for an addition reaction with a vinyl group, and the hydrogen atom directly connected to the elementary atom may be in the same molecule as the vinyl group, and
Even if it is a mixture of organopolysiloxane having at least two vinyl groups bonded to elementary atoms in one molecule and organohydrogenpolysiloxane having at least two hydrogen atoms bonded to silicon atoms in one molecule. However, in any case, the ratio of the number of hydrogen atoms directly bonded to silicon atoms to the number of vinyl groups is preferably within the range of 0.75 to 2.0.

It is desirable that such organopolysiloxane resin is a pulverizable solid at room temperature and easily melted by heating, and the siloxane resin has a particle size of 30 mesh or more, preferably 50 mesh or more. is preferred.

Next, as the curing catalyst that can be used in the present invention, any conventionally known catalyst can be used depending on the mechanism of the crosslinking curing reaction. If it has a directly linked hydroxyl group, zinc stearate, iron octylate, lead octylate,
Organic acid salts of metals such as octyl tin, dibutyl tin diacetylate, and dibutyl tin dilaurate, and amine compounds such as dibutylamine, triethanolamine, ethylene diamine, and triethylene diamine are used, and the organopolysiloxane resin is・When it has a vinyl group bonded to an elementary atom, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide,
Organic peroxides such as dicumyl peroxide, di-te-9-butyl peroxide, and rt-butyl perbenzoate are used, and the organopolysiloxane resin contains vinyl atoms bonded to elementary atoms in one molecule. If it is a mixture of an organopolysiloxane resin and an organohydrogenpolysiloxane having a group and a hydrogen atom or a vinyl group bonded to a silicon atom, platinum,
Used are chloroplatinic acid, a complex of chloroplatinic acid and alcohol, ether, aldehyde, etc., and carriers such as alumina, silica gel, asbestos, etc. in which platinum is supported.

Next, as the glass fiber that can be used in the present invention, various conventionally known glass fibers can be used, but in the present invention, the fiber length is 1 to 1.
It is essential to use a substance in the range of 0 to 5, preferably 3 to 5.

This is because when using fibers with a fiber length of less than one fiber, it is not possible to obtain a molded product with excellent mechanical strength, and on the other hand,
If fibers with a length exceeding 100 mm are used, it becomes difficult to develop them into layers, resulting in the inconvenience that it is difficult to obtain a uniform composition. In general, glass fibers are surface-treated with a so-called coupling agent to increase their affinity with resins, and they also have polymeric substances, organic substances such as oils and fats, and water attached to their surfaces, but these Ideally, this glass fiber should be heat-cleaned or chemically cleaned to avoid compatibility with the polysiloxane resin, but in reality, long glass fiber products other than glass cloth should be coated with organic substances as much as possible. You can use a commercially available product with a small amount of organic substances, but if the amount of organic substances attached is extremely small, for example, when cutting the roving into lengths of 1~low cape, it will become fluffy and continuous cutting will not be possible. This has the disadvantage of interfering with the next process.

In the present invention, the amount of attached organic substances, etc. is 1.0% by weight.
As mentioned above, it is preferable to use a hard chopped strand which is preferably about 3% by weight and is heated at a temperature of 350 to 400 pm to remove 90% or more of the attached organic matter.

The ratio of the above-mentioned thermosetting organopolysiloxane resin and glass fiber is 10 parts of the above-mentioned organopolysiloxane resin.
-9 parts by weight, preferably 20-7 parts by weight of glass fibers to 90-1 parts by weight, preferably 80-3 parts by weight.

This is because if the proportion of organopolysiloxane resin is below this range, the flow of the composition during molding will be poor and it will not be possible to obtain a good molded product.On the other hand, if it exceeds this range, the flow will become large and the molded product will not be able to be obtained. This is because it has many "s" and has poor mechanical strength. In addition, it is sufficient to use the curing catalyst in the usual amount, that is, in the range of 0.05 to 5 parts by weight based on 100 parts by weight of the above-mentioned thermosetting organopolytic IJ siloxane resin. There is no problem in increasing or decreasing the amount as appropriate depending on the desired curing time and the like.

To carry out the method of the present invention, first, a curing catalyst and other additives as necessary are uniformly mixed into a thermosetting organopolysiloxane resin using a high-speed stirrer such as a Henschel mixer. Alternatively, after kneading at the melting temperature of the organopolysiloxane resin using a heated roll or kneader, cooling and pulverizing, or further mixing them with a solvent and removing the solvent,
Glass fibers are layered on a finely pulverized mixed powder, the resin is melted, and then cooled. Thermosetting organopolysiloxane resin, curing catalyst, and glass fiber are spread out simultaneously or in advance into a layer, and then a mixed powder is spread on top of this, and then the same film or metal foil as described above is spread. or covered with a plate-shaped body and heated to above the melting point of the organopolysiloxane resin or heated under pressure,
A method may be adopted in which the resin is melted and then compressed and cooled. According to this method, a thermosetting organopolysiloxane composite material in the form of a sheet or plate can be obtained. The synthetic resin films used in the above prevent the organopolysiloxane resin from breaking or scattering,
In addition, it is possible to prevent the escape of the sublimable substance added to the composition as necessary, and to facilitate the handling of the obtained composite material. Any material may be used as long as it has a melting point higher than the softening point of the resin and has good malleability and thermal conductivity.Specifically, materials made of synthetic resins such as polyethylene, polyester, Teflon, and Tetron, aluminum, stainless steel, and iron. Examples include foils or plate-shaped bodies made of metals such as.

In addition, this film has a thickness of 1 to 1 for ease of use.
A film of 100 μm is preferable, and in the present invention, it is particularly preferable to use a synthetic resin film.

In order to obtain a molded article using the organopolysiloxane composite material of the present invention obtained as described above, various molding methods are employed to mold the molded article from conventional organopolysiloxane resin. Molding may be performed under almost the same conditions as .

Additives that may be added to the thermosetting organopolysiloxane resin of the present invention as necessary include, for example, a mold release agent,
Examples include thickeners, stabilizers, plasticizers, pigments, dyes, extenders, and fillers other than glass fibers.

Next, examples of the present invention will be given. In each example, all parts indicate parts by weight, and the bending strength, impact strength, and compressive strength are all JISK 69.
Measured according to 11.

Example 1 Methyl group (Me
) molar ratio (Me/Ph) is 0.9 poppy, elementary atoms (S
The molar ratio (R/Si) of the organic group (R) to i) is 1.
10 parts of methylphenylpolysiloxane resin with a hydroxyl group content of 3.2% by weight and a melting point of about 60 oo, 20 parts of quartz powder, 1.0 part of zinc stearate (lubricant), 1.0 parts of neutral lead carbonate. Anchor and benzoic acid 1. The anchor portion was stirred at high speed for 1 minute using a Henschel mixer, and then powdered to obtain a 60-mesh full-pass mixed powder.

On the other hand, chopped strands (product name: FECS-○0
6-0408, made by Fuji fiberglass, fiber length 6 ribs)
The 12 anchors were placed in a metal container and heat-treated in a 350 qo blower oven for 5 days to obtain heat-cleaned chopped strands (weight loss due to this heat treatment was 0.62%). Next, a polyethylene net with a mesh opening of 6 sides was placed on a polyester transparent film with a thickness of 10 mm, and the 4 chopped strands obtained above were placed on it and lightly vibrated to disperse it evenly. Next, the base of the mixed powder 4 obtained above was evenly spread, and on top of this, the layer of the chopped strand 4 and the mixed powder 4 Hakari were further spread, and this operation was repeated 3 times to form 3 layers. The above film was layered thereon. This whole thing is 130
After being placed in a blower oven at 150 °C and left for 3 minutes, it was taken out, quickly clamped between iron plates, and cooled by pressing at a pressure of 150 °C. Next, when the film was peeled off,
A sheet-like molding material is obtained, which has a thickness of 2.5 to 3
．． The bulk specific gravity was 1.1. This is compression molded,
When the mechanical properties of the obtained molded body were examined, the following results were obtained. bending strength
11.5kg/cooperative impact strength
60k9・Skin/Skin compression strength
6kg/Kyo* Heat shock test: No cracks * A disk with a diameter of 10 moulds, and a thickness of 4 sails was formed, heated to 35 mm, then placed in cold water (500 mm) and left for 1 hour. Changes in appearance were observed with the naked eye to determine the presence or absence of cracks (the same applies hereinafter).

Example 2 The molar ratio (Me/Ph) of methyl group (Me) to phenyl group (Ph) is 3.1, and the molar ratio (R/Si) of organic group (R) to elementary atom (Si) is 1. Of this R, the molar ratio of vinyl groups (Vi) to elementary atoms (Vi/Sj) is 0.40, and the hydroxyl group content is 1.35.
5% by weight, 10 parts of methylphenylpolysiloxane resin with a melting point of about 55°C, 10 parts of poppy, stone powder, 1. dicumyl peroxide. After adding 1.0 part of calcium stearate and 1.0 part of calcium stearate (boar powder) and stirring and mixing for 2 minutes using a Henschel mixer, this was pulverized to obtain a mixed powder of 60 mesh pass.

On the other hand, chopped strand (product name: FECS-G0
6-122 pine, made of Fuji fiberglass, fiber length 6 sides)
Ten anchors were heat-treated at 40,000 for 2 days to obtain heat-cleaned chopped strands (weight loss due to this heat treatment was 1.08%).

Next, chopped strands 5 were placed on a polyester transparent film having a thickness loAm using the same device as in Example 1.
55 parts of the mixed powder obtained above was further sprinkled on top of this, and after repeating this operation twice to form two layers, the film was placed again and this was heated with air at 100°C. Put it in the oven for 3 minutes, then take it out and quickly clamp it between iron plates.15
It was compressed and cooled by applying a pressure of 0 pm/earth.

The sheet-like molding material obtained by peeling off the film had a thickness of 2.5 to 3.0 mm and a basket specific gravity of 1.0. Next, the molding material obtained above was compression molded, and the mechanical properties of the obtained molded product were examined, and the results shown below were obtained.

Bending strength 10.5X9/pine Impact strength 60k9/arc/compression strength
5k9/fence heat shock test No cracks occurred Example 3 Mixed powder used in Example 1 and chopped strands (product name: CS
- JA-861A, manufactured by Asahi Fiberglass Co., Ltd., organic matter adhesion 0.2%, fiber length 10 ribs) was passed through a polyethylene net with a 13-mesh opening on a Teflon film so that their weight ratio was 1:1. The mixture was sprayed in three layers alternately, and then the Teflon film was placed again and heat treated for 3 minutes using a 130 mm open oven to obtain a sheet-like molding material.

When this material was compression molded and the mechanical properties of the obtained molded product were examined, the following results were obtained.
Bending strength 13.0k9/Hiro Impact strength 70kg/Skin/Skin compression strength
5k9/fence heat shock test No cracks occurred Example 4 Poppy, all organic groups bonded to elementary atoms are methyl groups (Me/Si=1.0
), the hydroxyl group content is 5.5% by weight, and the melting point is about 75qo
Methyl polysiloxane resin 10 parts, neutral lead carbonate 0.
7 parts, benzoic acid 0.7 parts and zinc stearate 1.0 parts
The mixture was stirred and mixed for 2 minutes using a Henschel mixer, and then pulverized to obtain a mixed powder of 80 mesh all passes.

Next, 10 anchor parts of the heat-cleaned chopped strands used in Example 2 and 7 anchor parts of the mixed powder obtained above were simultaneously sprinkled onto the polyester film, and then the film was Re-lay, 15
After heating at 0℃ for 2 minutes, press and cool to a thickness of 1.5~2
．． A sheet-shaped molding material with a cage specific gravity of 1.0 was obtained. When this molding material was compression molded and the mechanical properties of the obtained molded product were examined, the following results were obtained. Bending strength: 12.5k9/Hiro impact strength: 60k9/Skin compression strength: 6.5k9/Matsu heat shock test: No cracks were generated Example 5: The methylpolysiloxane resin used in Example 4, 10 types of quartz fine 300 parts of powder, 1.0 part of zinc stearate, 0.0 parts of neutral lead carbonate.
7 parts of benzoic acid, 0.7 parts of benzoic acid, and 5 parts of iron oxide (red iron oxide) were mixed uniformly using a hot roll heated to 100°C, and after cooling, a mixed powder was prepared using a pulverizer and passed through 100 mesh. I got it.

This powder was mixed with the 80 mesh full-pass mixed powder used in Example 4 by high-speed stirring for 1 minute using a Henschel mixer. Next, the heat-cleaned chopped strands used in Example 2 and the mixed powder obtained above were simultaneously sprinkled on a polyester film at a ratio of 1:2 (weight ratio), and then Place the film in a 140 qo oven and heat for 2 minutes, then press and cool to a thickness of 2.0 to 2.5.
A sheet-like molding material having a bulk specific gravity of 1.2 was obtained.

This product was compression molded, and the mechanical properties of the resulting molded product were examined, and the results shown below were obtained. Bending strength 11.3k9/Muse impact strength Mottled kg/Suppression/Compressive strength
6.0k9/masu heat shock test No crack occurred Example 6 Phenyl group (Ph
), the molar ratio (Me/Ph) of methyl group (Me) to
The molar ratio (R to Si) is 1.10, and the hydroxyl group content is 4.
5% by weight, 10 strands of methylphenylpolysiloxane resin with a melting point of approximately 80mm, 1 bale of diatomaceous earth (product name: Celite Super Floss, manufactured by John Manville), 15 strands of fused silica powder, basic 0.7 parts of lead carbonate, 0.8 parts of 2-ethylhexylic acid and 1.0 parts of calcium stearate. The anchor part was uniformly stirred and mixed in a ball mill with 30 degrees of toluene, and the toluene was removed under reduced pressure while heating to 80 degrees, and the remaining solid was crushed using a crusher to 100 degrees.
A mixed powder of all mesh passes was obtained.

Next, the chopped strands used in Example 3 and the mixed powder obtained above were alternately sprinkled on a polyester film in three layers at a ratio of 1:3 (weight ratio). A film was placed on top and heat treated at 14,000 for 2 minutes, followed by compression cooling to obtain a sheet-like molding material having 2.0 to 2.5 ribs and a bulk specific gravity of 1.4. When this material was compression molded and the mechanical properties of the obtained molded product were examined, the following results were obtained. bending strength
9.8kg'Iso impact strength
60k9・Skin/Skin compression strength
7.2k9/Match Heat Shock Test No cracks were generated Example 7 The molar ratio of methyl group (Me) to phenyl group (Ph) (Me/Ph) was 1.4 or more.
Poppy, molar ratio of organic group (R) to elementary atom (Si) (
R/Si) is 1.27, and the molar ratio of vinyl group (Vi) to silicon atom (Si) among organic groups (R) (Vi/S
i) 63 parts of a pinyl group-containing organopolysiloxane having a melting point of about 0.2 and a molar ratio of methyl groups (Me) to phenyl groups (Ph) (Me/Ph) of 3.90,
Poppy, molar ratio of organic group (R) to elementary atom (Si) (
R/Si) is 1.71, the molar ratio of hydrogen atoms (H) to elementary atoms (Si) (H/Si
) was mixed with 35 parts of organohydrogenpolysiloxane having a melting point of about 40 qo and a melting point of about 40 qo.

To this, 170 parts of fused quartz powder, 0 parts of calcium stearate
．． 5 parts of platinum, 0.02 parts of a 1:1 (weight ratio) mixture of a 2-ethylhexanol-modified chloroplatinic acid solution with a concentration of 2% as platinum and a catalyst activity inhibitor represented by the formula, and
The mixture was uniformly kneaded with a No. 00 hot roll, cooled, and then ground into a 60-mesh full pass using a grinder to obtain a mixed powder.

Next, the chopped strands used in Example 3 and the mixed powder obtained above were simultaneously spread on a polyester film at a ratio (weight ratio) of 1:4, and then heated at 110°C. Heat-treated in an oven for 2 minutes, then compressed and cooled to obtain a sheet-shaped molding material with a thickness of 2.0 to 2.5 willow and a bulk specific gravity of 1.0. This sheet-shaped molding material was compression-molded, When the mechanical properties of the obtained molded body were examined, the following results were obtained. Bending strength: 8.5kg/Son Impact strength: 55k9/Skin' pressure stripe strength
6.5k9/Hiro Heat Shock Test No cracks occurred Example 8 Phenyl group (Ph
), the molar ratio (Me/Ph) of methyl groups (Me) to
The molar ratio (R/Sj) is 1.10, and the hydroxyl group content is 4.
3%, methylphenylpolysiloxane resin with a melting point of about 85°C, all of the organic acids bonded to the elementary atoms are methyl groups (Me/Si=1.0), and the hydroxyl group content is 4.
% by weight, 50 parts of methylpolysiloxane resin with a melting point of about 90 qo, 10 parts of poppy, stone powder, 1. zinc stearate.
0 parts of neutral lead carbonate, 0.8 parts of benzoic acid, and 5 parts of black pigment were uniformly melted and kneaded using hot rolls heated to 110 pm, cooled, and then crushed to pass through 100 mesh. A mixed powder was obtained.

Next, the heat-cleaned chopped strands used in Example 1 and the mixed powder obtained above were simultaneously spread on a polyether film at a ratio (weight ratio) of 2:5. , sent the film to war,
When this was heat-treated to 155 oo for 2 minutes and then compressed and cooled, a sheet-like molding material having a thickness of 2.0 to 2.5 and a basket specific gravity of 1.0 was obtained.

When the mechanical properties of the molded body obtained by compression molding this molding material were investigated, the following results were obtained. Bending strength: 10.5k9/Impact resistance: 50k9/Arc/Kagami Compressive strength: 6k9/Iso heat shock test No cracks Comparative example The mixed powder obtained in Example 1 was dispersed in toluene and milled in a ball mill. Inside 1
A coating solution was prepared by mixing for a certain amount of time.

Next, the coating liquid was uniformly applied to the heat-cleaned chopped strands used in Example 1 so that the amount of adhesion was 50% (the amount of adhesion in the entire coating liquid system), and then 90% of the coating liquid was applied.
When the toluene was evaporated off by heating at 0.000 m for 30 minutes and the fiber length was cut into approximately 6 sides, a fibrous and bulky molding material with a bulk specific gravity of 0.3 was obtained.

Claims (1)

[Scope of Claims] 1 A mixed powder of 10 to 90 parts by weight of a thermosetting organopolysiloxane resin and a catalytic amount of a curing catalyst is added with a fiber length of 1
A method for producing a thermosetting organopolysiloxane composite material, which comprises stacking 90 to 10 parts by weight of glass fibers of ~100 mm to melt the resin and then cooling it. 2 A mixed powder of 10 to 90 parts by weight of a thermosetting organopolysiloxane resin and a catalytic amount of a curing catalyst is mixed with 90 to 10 parts of glass fibers with a fiber length of 1 to 100 mm spread out in layers.
The method for producing a thermosetting organopolysiloxane composite material according to claim 1, characterized in that the resin is sprayed on 0 parts by weight, then the resin is melted and then cooled. 3. The method for producing a thermosetting organopolysiloxane composite material according to claim 1 or 2, wherein the resin is melted under pressure.