JPH1142678A - Manufacture of bonding composite of aromatic polyamide resin and silicone rubber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a bonding composite, in which can aromatic polyamide resin and a silicone rubber are strongly bonded together, with a favorable production efficiency. SOLUTION: After a pre-formed aromatic polyamide resin formed body is inserted in the cavity of a mold for arranging at a predetermined position, an addition reaction type liquid silicone rubber composition with a siloxane compound respectively having hydrogen atoms directly linked to a silicon atom and, at the same time, a phenyl group and an ester linkage as an adhesion imparting component is injected in the cavity of a mold heated up to 100-180 deg.C so as to harden under heat.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an adhesive composite of an aromatic polyamide resin and a silicone rubber, and more particularly, to an electric, electronic, automobile, precision instrument,
The present invention relates to a method for producing an adhesive composite in which an aromatic polyamide resin and a silicone rubber widely used in the field of medical equipment and the like are well bonded.

[0002]

2. Description of the Related Art In recent years, electricity, electronics, automobiles, precision equipment,
In the field of medical equipment and the like, thermoplastic resins such as polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, polyamide, and polycarbonate are widely used, and a method of bonding such a thermoplastic resin and silicone rubber is also used. Many have been proposed.

Hitherto, as a method of bonding a thermoplastic resin and silicone rubber, for example, a method has been proposed in which a primer is applied or sprayed onto the surface of a molded article of a thermoplastic resin (Japanese Patent Application Laid-Open No. Sho 62-264920). No.). However, in this method, the primer must be applied after the molded body is once taken out of the mold, and complicated process control is required. Therefore, there is a problem that the production efficiency is low in terms of industrial use.

Further, in order to obtain an adhesive composite of a thermoplastic resin and a silicone rubber, there has been proposed a method of using a self-adhesive silicone rubber to which a component for improving the adhesiveness (adhesion improving agent) is added. As an adhesion improver, a polysiloxane having a hydrogen atom bonded to a silicon atom and a trialkoxysilylalkyl group (JP-A-48-169)
No. 52), silane or siloxane having an acryloxyalkyl group and an organic peroxide (described in JP-A-50-26855), an epoxy group and / or an ester group on a silicon atom and hydrogen directly bonded to the silicon atom. A polysiloxane having an atom (described in JP-A-50-39345) has been proposed. However, none of these methods resulted in satisfactory adhesive strength.

Further, Japanese Patent Application Laid-Open Nos.
As disclosed in JP-A-84780, there is also known a method for producing an adhesive composite in which injection molding is performed using a mold. However, although the addition reaction type liquid silicone rubbers described in these methods show good adhesion to aliphatic polyamide resins such as nylon-6,
It did not adhere to the aromatic polyamide resin, and therefore, an adhesive composite of the aromatic polyamide resin and silicone rubber could not be obtained by these methods. Further, in these methods, since the silicone rubber composition also has an adhesive property to a metal material, it is necessary to use an expensive mold surface-treated with a fluororesin or the like. However, a mold having a complicated structure or a mold having a slide, a protruding pin, and the like has a problem that durability is not sufficient.

[0006]

As described above, the conventional adhesive silicone rubber composition does not provide a satisfactory adhesive strength to a thermoplastic resin or has a good adhesive strength to a thermoplastic resin. However, a material suitable for forming an adhesive composite with a thermoplastic resin using a mold has not been obtained.

[0007] In particular, it is extremely difficult to obtain an adhesive composite with silicone rubber in the case of an aromatic polyamide resin among thermoplastic resins. That is, the aromatic polyamide resin has lower water absorption than other thermoplastic resins,
Because of its excellent creep resistance, fatigue resistance, heat aging resistance, weather resistance, oil resistance, and flame retardancy, it is used in many applications such as automotive connectors and housings. In the connector, a silicone rubber containing a phenyl group-containing polyorganosiloxane having an oil bleed property is used as a sealing material in terms of workability at the time of assembly, detachability, waterproofness, and the like. With silicone rubber, adhesion to an aromatic polyamide resin is hindered by bleeding (leaching) silicone oil, and it has been difficult to obtain an adhesive composite.

The present invention has been made to solve these problems, and an adhesive composite in which an aromatic polyamide resin and a silicone rubber are firmly adhered to each other is manufactured with high productivity using a mold. The aim is to provide a method.

[0009]

The process for producing an adhesive composite of an aromatic polyamide resin and a silicone rubber according to the present invention comprises:
After inserting and arranging the molded article made of the aromatic polyamide resin into the cavity of the mold, as a component for imparting adhesion, one molecule has at least one hydrogen atom directly bonded to a silicon atom, and at least one An addition-reaction liquid silicone rubber composition containing a siloxane compound having a phenyl group and an ester bond is contacted with the molded body in a cavity of the mold heated to a temperature of 130 to 180 ° C. It is characterized in that it is injected and then cured by heating.

The aromatic polyamide resin used in the present invention is a polyamide resin having an aromatic ring in a molecular chain,
For example, nylon MXD6 (manufactured by Mitsubishi Engineering-Plastics Corporation) represented by the following chemical formula is exemplified.

[0011]

Embedded image In addition, as a commercially available aromatic polyamide resin, PA-MCX manufactured by Mitsui Petrochemical Co., H-PA manufactured by Ube Industries, H-PA manufactured by Teijin Amoco Engineering Plastics, and durethane manufactured by Bayer are used. be able to.

Next, the addition reaction type liquid silicone rubber composition used in the present invention will be described in detail below.

This liquid silicone rubber composition comprises, as an adhesion-imparting component, a siloxane compound having at least one hydrogen atom directly bonded to a silicon atom in one molecule and having at least one phenyl group and an ester bond. It is blended. Examples of such a siloxane compound include compounds each having a (CH ₃ ) HSiO unit and a siloxane unit having an ester bond and a phenyl group represented by the following chemical formula.

[0014]

Embedded image Further, the liquid silicone rubber composition used in the present invention includes (A) an alkenyl group-containing polyorganosiloxane and (B) a polyorganohydrogen having two or more hydrogen atoms directly bonded to silicon atoms in one molecule. Siloxane, (C) a reinforcing filler, (D) an addition reaction catalyst selected from the group consisting of platinum or a platinum compound, and (E) 1-propoxybenzoate as an adhesion-imparting component.
It is desirable to use an adhesive silicone rubber composition containing -1,3,5,7-tetramethylcyclotetrasiloxane. Such an adhesive silicone rubber composition has good adhesiveness to an aromatic polyamide resin and hardly adheres to a metal, so that the resin and the silicone rubber have good adhesion. The composite can be efficiently manufactured using a mold.

Here, the alkenyl group-containing polyorganosiloxane (A) constituting the adhesive silicone rubber composition has a general formula: R ¹ _a R ² _b SiO
_{{4- (a + b)} / 2} (wherein R ¹ represents an alkenyl group;
² is a substituted or unsubstituted 1 which does not contain an aliphatic unsaturated bond.
Represents a monovalent hydrocarbon group. A is an integer of 1 to 3, and b is an integer of 0 to 2. However, a + b is an integer of 1-3. A) having at least two alkenyl groups R ¹ in one molecule at 25 ° C.
Is a polyorganosiloxane having a viscosity of 1,000 to 100,000 cp.

Examples of R ¹ include a vinyl group, an allyl group (2-propenyl group), a 1-butenyl group, a 1-hexenyl group, and the like, but a vinyl group is preferable because of ease of synthesis. Examples of the organic group bonded to the silicon atom of R ² and other siloxane units include an alkyl group such as a methyl group, an ethyl group and a propyl group, an aryl group such as a phenyl group and a tolyl group, and an aralkyl group such as a 2-phenylethyl group. And substituted hydrocarbon groups such as chloromethyl group and 3,3,3-trifluoropropyl group. It is most desirable to use a methyl group among these organic groups because of ease of synthesis. Further, when a methyl group is used, the obtained silicone rubber composition has an advantage that it retains a low viscosity before curing, has a sufficient degree of polymerization after curing, and has good physical properties. Furthermore, if the cured product requires cold resistance, a phenyl group may be selected, and if oil resistance is required, a small amount of a 3,3,3-trifluoropropyl group may be introduced. it can.

The polyorganohydrogensiloxane of the component (B) has the general formula: R ³ _{c Hd} SiO
_{{4- (c + d)} / 2} (wherein, R ³ represents a substituted or unsubstituted monovalent hydrocarbon group; and c is an integer of 0 to 2,
d is an integer of 1 to 3. Here, c + d is an integer of 1 to 3. A) a polyorganosiloxane having a siloxane unit represented by the formula (1) and having at least two hydrogen atoms directly bonded to silicon atoms in one molecule, and reacting with the polyorganosiloxane of the component (A) to act as a crosslinking agent It is.

The number of hydrogen atoms bonded to a silicon atom is
The number of components (B) is more than two in one molecule as a whole, and particularly preferably three or more when mechanical strength is required. Examples of the organic group bonded to the silicon atom of R ³ and other siloxane units include the same organic groups as those of R ^{2 in the} component (A), and most preferably a methyl group from the viewpoint of easy synthesis.

The amount of component (B) is preferably such that the number of hydrogen atoms bonded to silicon atoms is 0.5 to 4 per alkenyl group of component (A), and more preferably 1 to 4.
It is an amount that will be ~ 3 pieces. If the number of hydrogen atoms per alkenyl group is less than 0.5, curing will not proceed sufficiently,
A cured product of the desired strength cannot be obtained. The number of hydrogen atoms is 4
Exceeding the number is undesirable because the physical properties and heat resistance after curing are reduced.

As the reinforcing filler of the component (C), a silica filler that imparts strength to the cured silicone rubber can be used. In particular, the specific surface area is 50m, such as fumed silica, surface-treated fumed silica, and precipitated silica.
^It is preferred to use finely divided silica of ² / g or more. Commercial products of such finely divided silica include Aerosil 130,
200, 300, and R972 (all manufactured by Nippon Aerosil Co., Ltd.).

The compounding amount of the component (C) is preferably 5 to 60 parts by weight based on 100 parts by weight of the alkenyl group-containing polyorganosiloxane of the component (A). If the amount of the component (C) is less than 5 parts by weight, no reinforcing effect is exhibited by the compounding. On the other hand, if it exceeds 60 parts by weight, other physical properties such as elongation, tensile strength, and tear strength are reduced. Not preferred.

The catalyst selected from the group consisting of platinum or a platinum compound as the component (D) includes (A) an alkenyl group of the polyorganosiloxane and (B) a hydrogen atom directly bonded to a silicon atom of the polyorganohydrogensiloxane ( And a hydrogen group).
Platinum alone (platinum black), chloroplatinic acid, complexes obtained from chloroplatinic acid and alcohol, platinum-olefin complexes, platinum-vinylsiloxane complexes, platinum-triphenylphosphine complexes, other platinum coordination compounds, or alumina,
A carrier in which platinum alone is supported on a carrier such as silica can be used. As the chloroplatinic acid or the platinum-olefin complex, it is desirable to use those dissolved in an alcohol solvent, a ketone solvent, an ether solvent, a hydrocarbon solvent, or the like.

The amount of the component (D) is appropriately increased or decreased depending on the curing speed. Usually, the amount of platinum atoms relative to the component (A) is as small as 0.1 to 100 ppm, and the effect of accelerating the crosslinking is sufficient. In particular, a range of 1 to 30 ppm is effective. (D) The compounding amount of the component is 0.1 ppm as platinum atom.
If it is less than 10, curing will not proceed sufficiently, and even if it exceeds 100 ppm, especially improvement of the curing speed cannot be expected.

Component (E) 1-propoxybenzoate-
1,3,5,7-Tetramethylcyclotetrasiloxane is a siloxane compound (polysiloxane) represented by the following structural formula. By using a compound having such a structure as an adhesion-imparting component, an aromatic compound is obtained. For polyamide resin,
High adhesive strength, which cannot be obtained by using other siloxane compounds, can be obtained.

[0025]

Embedded image The amount of the component (E) is based on 100 parts by weight of the component (A).
Desirably 0.5 to 5 parts by weight, more preferably
1 to 3 parts by weight. If the amount of the component (E) is less than 0.5 part by weight, the adhesiveness to the aromatic polyamide resin is insufficiently developed. If the amount exceeds 5 parts by weight, the effect of improving the adhesiveness is not changed. Properties such as strength are undesirably reduced.

The adhesive silicone rubber composition containing the above components (A) to (E) may further contain (F) a phenyl group-containing polyorganosiloxane. The phenyl group-containing polyorganosiloxane imparts oil bleeding properties to the cured silicone rubber, and imparts waterproofness and sealing properties to the adhesive composite. The silicone oil that bleeds (bleeds) onto the surface of the cured silicone rubber acts as a mold release agent for the mold, and facilitates removal of the adhesive composite from the mold. Here, the content ratio of the phenyl group in the (F) phenyl group-containing polyorganosiloxane is preferably from 5 to 35 mol%. If the amount is less than 5 mol%, the effect of imparting oil bleeding property to the cured silicone rubber is not sufficiently exhibited. On the other hand, a polyorganosiloxane having a phenyl group content of more than 35 mol% is not preferable because the amount of the bleeding silicone oil becomes too large and the adhesiveness to the aromatic polyamide resin becomes worse.

The amount of the component (F) is preferably 10 parts by weight or less, more preferably 2 to 5 parts by weight, per 100 parts by weight of the component (A). When the blending amount of the (F) phenyl group-containing polyorganosiloxane exceeds 10 parts by weight per 100 parts by weight of the component (A), the bleed amount of the silicone oil becomes too large, and the adhesiveness to the resin deteriorates.

Further, such an adhesive silicone rubber composition may be appropriately compounded with a commonly used additive as required. As additives, non-reinforcing fillers such as quartz powder, diatomaceous earth, calcium carbonate, pigments, known flame retardants, heat resistance improvers such as iron oxide, cerium oxide, iron carboxylate, and rare earth organic acid salts And the like. Further, a crosslinking reaction retarder such as acetylene alcohol can be added for the purpose of increasing the stability during storage at room temperature.

In the present invention, in order to produce such an adhesive composite of the adhesive silicone rubber composition and the aromatic polyamide resin, first, a molded article made of an aromatic polyamide resin molded by a known method is used. Is inserted into a predetermined position in the cavity of the mold and arranged. Then, a method of injecting an uncured addition-reaction-type liquid silicone rubber composition into the cavity of the heated mold and bringing it into contact with the resin molded body, and then heating and curing in the mold as it is, is adopted. The injection temperature (mold temperature) of the liquid silicone rubber composition
Is desirably 100 to 180 ° C. If the injection molding temperature is lower than 100 ° C, the adhesiveness is not sufficiently developed.
If the temperature is higher than 80 ° C., the dimensional accuracy of the resin molded product deteriorates, which is not preferable.

In the present invention, after a preformed aromatic polyamide resin molded article is inserted and arranged at a predetermined position in a mold cavity, an addition reaction type liquid containing an adhesion imparting component is mixed into the cavity. Since the silicone rubber composition is injected and cured by heating, the silicone rubber adheres only to the aromatic polyamide resin molded article without adhering to the mold, and the aromatic polyamide resin and the silicone rubber are firmly adhered. The body can be obtained with high production efficiency. In the obtained adhesive composite, the properties of both the aromatic polyamide resin and the silicone rubber are sufficiently exhibited, and can be effectively used in the fields of electricity, electronics, automobiles, precision equipment, medical equipment and the like. .

[0031]

Embodiments of the present invention will be described below. In the following text, all “parts” indicate “parts by weight”.

Examples 1 and 2 [Preparation of silicone rubber composition] (A) Polydimethylsiloxane in which both ends are blocked with dimethylvinyl groups (viscosity at 25 ° C of 10,000 cp)
100 parts and (C) 40 parts of finely divided silica obtained by treating Aerosil 200 with octamethyltetracyclosiloxane were charged into a kneader, and stirred and mixed at room temperature for 1 hour.
The temperature was raised to 150 ° C., and the mixture was heated and mixed for 2 hours. Thereafter, the mixture was cooled to room temperature, and (B) (CH ₃ ) HS
67 mol% of 1/2 unit of iO and 33 mol% of (CH ₃ ) ₂ SiO unit
1.5 parts of polymethylhydrogensiloxane and 0.3 parts of (D) a platinum-vinylsiloxane complex solution (platinum atom content: 0.5 wt%) were added and mixed until uniform. The composition was then added to the composition as shown in Table 1.
One part of (E) -1 is added as an adhesion-imparting component,
In Example 1, (F) the phenyl group content was further increased.
A silicone rubber composition was prepared by mixing 3 parts of a 28 mol% phenyl group-containing polyorganosiloxane having a viscosity of 200 cP at 25 ° C. and mixing well until uniform. As a comparative example, a silicone rubber composition was prepared by blending (E) -2 and the (F) component at the ratios shown in Table 1 with the above-described composition.

(E) -1 is 1-propoxybenzoate-1,3,5,7-tetramethylcyclotetrasiloxane represented by the aforementioned chemical formula (I), and (E) -2 is The following chemical formula

Embedded image A tetrasiloxane having a glycidoxy group represented by the following formula was used.

[Production of Aromatic Polyamide Resin Molded Body] H-PA of Teijin Amoco Engineering Plastics Co., Ltd. was injected into a thermoplastic resin injection molding machine, melt-plasticized, and then injected into a mold cavity. Width 10mm × length 10
A small piece of an aromatic polyamide resin molded article having a size of mm × 1 mm was obtained. The injection conditions were that the mold clamping pressure was 200kgf /
cm ² , injection time 2 seconds, cooling time 20 seconds, mold temperature 100 ° C.

Next, the aromatic polyamide resin molded article is inserted and arranged at a predetermined position in a mold cavity of an injection molding apparatus, and the mold is clamped at a pressure of about 120 kgf / cm ^2. Was heated to a temperature of 140 ° C. Then, the silicone rubber compositions of Examples 1 and 2 and Comparative Examples 1 and 2 were injected into the cavities at an injection pressure of 50 kgf / cm ² (the rear end of the screw) for about 4 seconds, and then heated for about 60 seconds. Subsequently, the mixture was cured to obtain a disc-shaped integral molded body (adhesive composite) having a diameter of 30 mm and a thickness of 3 mm.

Next, the adhesion test between the resin molded product and the silicone rubber molded product was performed on the thus obtained adhesive composite. Further, the ease of removal from the mold was examined. The test results are shown in the lower column of Table 1.

[0037]

[Table 1] From the results shown in Table 1, in the adhesive composites obtained in Examples 1 and 2, the aromatic polyamide resin molded article and the silicone rubber molded article were firmly adhered to each other. It was found that the amount of oil to bleed was appropriate and it was easy to extract from the mold. In contrast, in the adhesive composite obtained in the comparative example,
The adhesion between the aromatic polyamide resin molded article and the silicone rubber molded article was insufficient, and it was easy to peel off.

[0038]

As is apparent from the above description, according to the present invention, after the aromatic polyamide resin molded article is inserted and arranged in the mold, it has a hydrogen atom directly bonded to a silicon atom, and a phenyl group and an ester. Since the addition-reaction liquid silicone rubber containing a siloxane compound having a bond and an adhesion-imparting component is injected into the mold and cured by heating, the silicone rubber does not adhere to the mold, and the aromatic polyamide An adhesive composite in which the resin and the silicone rubber are firmly bonded can be obtained with high production efficiency. In addition, the obtained adhesive composite exhibits excellent properties of both the aromatic polyamide resin and the silicone rubber, and can be used for electric, electronic,
It is effectively used in the fields of automobiles, precision equipment, and the like.

[0039]

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Tatsuhiko Sawamura, Inventor 6-2-31 Roppongi, Minato-ku, Tokyo Inside Toshiba Silicone Corporation (72) Inventor Shuji Chiba 6-2-1, Roppongi, Minato-ku, Tokyo (72) Inventor Michio Zenbayashi 6-31 Roppongi, Minato-ku, Tokyo Toshiba Silicone Corporation

Claims (2)

[Claims] After inserting and arranging a molded article made of an aromatic polyamide resin into a cavity of a mold, it has at least one hydrogen atom directly bonded to a silicon atom in one molecule as an adhesion-imparting component, And an addition reaction type liquid silicone rubber composition containing a siloxane compound having at least one phenyl group and an ester bond,
Injection into the cavity of the mold heated to a temperature of 100 to 180 ° C. so as to be in contact with the molded body, and then heat-curing the molded body to bond the aromatic polyamide resin and the silicone rubber. A method for producing a composite. 2. The addition reaction type liquid silicone rubber composition according to claim 1, wherein (A) an alkenyl group-containing polyorganosiloxane and (B) a polyorganohydro having two or more hydrogen atoms directly bonded to silicon atoms in one molecule. Gensiloxane, (C) a reinforcing filler, (D) an addition reaction catalyst selected from the group consisting of platinum or a platinum compound, and (E) 1-propoxybenzoate as an adhesion-imparting component.
The method for producing an adhesive composite of an aromatic polyamide resin and a silicone rubber according to claim 1, which is an adhesive silicone rubber composition containing 1,3,5,7-tetramethylcyclotetrasiloxane.