JPH08156188A - Composite member consisting of plastic and rubber and production thereof - Google Patents

Abstract

PURPOSE: To omit or shorten a complicated process and to freely select a combination corresponding to a use by bonding a member composed of an epoxy group-containing resin compsn. and a vulcanized elastic rubber member having a carboxyl group and an acid anhydride group at the interface between them. CONSTITUTION: A composite member is produced by bringing a member composed of an epoxy group-containing resin compsn. and a member composed of an elastic rubber compsn. having a carboxyl group or an acid anhydride group compounded with a vulcanizing agent to a close contact state and vulcanizing the elastic rubber compsn. to strongly bond both members at the interface between them. When the composite member is produced by a two-stage method, a molded object of the epoxy group-containing resin compsn. produced by press molding, injection molding or extrusion molding and the elastic rubber compsn. having the carboxyl group or the acid anhydride group compounded with the vulcanizing agent are combined to be closely bonded and subsequently exposed to a predetermined rubber vulcanzing condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite member composed of a rubber component and an adhesive thermoplastic resin component and a method for producing the same.

[0002]

BACKGROUND OF THE INVENTION Rubber is sometimes used as a component of composite materials by adhesion with other materials such as metals, fibers and plastics. However, the adhesion of vulcanized rubber to other materials generally has to go through several steps.

When vulcanized rubber is regarded as an adherend, it differs from other adherends in that it contains many compounding agents such as a softening agent, a filler, a vulcanization accelerator, and an antiaging agent, in addition to rubber. It is that you are. Usually, the rubber surface is often contaminated by the adhesion of such blooms, dusting powder, and dust.

Therefore, when the vulcanized rubber is adhered to another material, 1) first, the surface of the rubber is roughened with sandpaper, a wire brush, blast, etc. 2) The rubber shavings adhering to the surface are removed by air. Or wipe with a solvent such as acetone, toluene, rubber volatile oil, etc. 3) Adhere with an appropriate primer or adhesive, and then dry.

However, non-polar rubbers such as natural rubber, styrene-butadiene rubber and ethylene-propylene rubber have poor "wetting" due to highly polar adhesives, and they are not compatible with the adhesive layer.
The secondary bond strength is also insufficient. In many cases, adhesives, primers and the like contain a solvent, and there are many problems in working environment or safety. Moreover, some of these cumbersome steps make automation of the process difficult.

[0006]

Several attempts have been made to simplify the process of bonding rubber to other materials.
For example, Japanese Unexamined Patent Publication (Kokai) No. 2-150439 describes a method for producing a chemical composite in which one side is a molding material having an aliphatic polyamide as a base material and the other side is a carboxyl group-containing rubber. The formation of amide bonds at the rubber-plastic interface achieves strong adhesion without adhesive.

However, since the formation of the amide bond in this case is performed by the reaction between the side chain carboxyl group in the rubber and the terminal amino group of the polyamide, when the polyamide has a high molecular weight, the concentration of the terminal amino group decreases. , Results in less amide covalent bonds at the interface and in some cases insufficient interfacial adhesion. Generally, it is difficult to synthesize a polyamide having an amino group in the side chain,
It is practically impossible to increase the amino group concentration unless measures such as blending are taken. Further, a polymer containing an amino group tends to be thickened due to a chemical change and has a high adhesiveness with a metal, so that it has a problem that extrusion and molding processability are poor.

Further, 1) the only general-purpose polymer having an amino group at the end is polyamide. 2) When rubber is directly vulcanized to plastic, the plastic is not allowed to undergo thermal deformation during the vulcanization process of rubber. The above-mentioned patent has a drawback in that the selection of resin is greatly restricted because a polymer having a heat distortion temperature higher than the vulcanization temperature of rubber is required for this purpose.

As a result of intensive studies to solve these technical problems, the inventor of the present invention has found that the combination of a specific vulcanized rubber composition and a specific thermoplastic resin composition causes the above-mentioned complicated physical and chemical reactions. The present invention has been achieved by finding that a composite member can be firmly bonded in one step without requiring treatment or use of an adhesive.

[0010]

That is, according to the present invention, a member made of a resin composition containing an epoxy group and an elastic rubber member having a vulcanized carboxyl group or acid anhydride group are bound at an interface. Which is a composite member composed of an epoxy group and an elastic rubber composition having a carboxyl group or an acid anhydride group blended with a vulcanizing agent, adhered and vulcanized to firmly bond both members at the interface. It is characterized by binding to.

The elastic rubber used is not particularly limited as long as it contains a carboxyl group or an acid anhydride group.
Specifically, natural rubber (NR), butadiene rubber (B
R), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), ethylene-propylene- (diene) -rubber (EPM or EPDM), chloroprene rubber (CR), isobutene-isoprene rubber (IIR), isoprene rubber (IR), acrylic rubber (ACM), ethylene-acrylic rubber and the like can be mentioned. Further, it may be an appropriate mixture of these various rubbers, or a mixture of a rubber containing a carboxyl group and a rubber not containing it.

To introduce a carboxyl group or an acid anhydride group into an elastic rubber, 1) a method of copolymerizing an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, sorbic acid, maleic acid or maleic anhydride, 2) elasticity A method of reacting the above-mentioned unsaturated carboxylic acid or the like with rubber in the presence of peroxide can be adopted.

As the filler used in the present invention, a general substance used in rubber compositions such as carbon black, silicic acid, silicates, calcium carbonate, zinc oxide, barium sulfate, kaolin and the like can be used. The blending amount of the filler can be arbitrarily determined in the range of 50 to 300 parts by weight with respect to 100 parts by weight of the elastic rubber having a carboxyl group or an acid anhydride group in order to satisfy the required physical properties of the rubber.

Examples of the vulcanizing agent used in the present invention include sulfur, sulfur compounds and organic peroxides.
Since the elastic rubber used in the present invention has a carboxyl group, it can be vulcanized even by using a polyvalent amine or a metal oxide. Examples of the sulfur compound other than sulfur include sulfur donors such as dithiodimorpholine, dipentamethylene thiuram hexasulfide, tetramethylene thiuram disulfide, 2-morpholino dithiodibenzothiazole and caprolactam disulfide.

Examples of organic peroxides include 2,5-
Dimethyl-2,5-bis (tertiary butyl peroxide)
Hexane, dicumyl peroxide, 4,4-di-tert-butylperoxy-n-butylvalerate, 1,1-di- (tert-butylperoxy) -3,3,5-trimethylcyclohexane and 1, 3-bis- (tertiary butyl peroxy isopropyl) benzene etc. can be mentioned.

As the polyvalent amine, hexamethylenediamine, triethylenetetramine, tetraethylenepentamine, hexamethylenediamine carbamate, ethylenediamine carbamate, 4,4'-methylene-bis (2
-Chloroaniline), triethylenediamine and the like. Examples of the metal oxide include zinc oxide, magnesium oxide, lead monoxide and the like. The compounding amount of these vulcanizing agents is preferably in the range of 1 to 10 parts by weight with respect to 100 parts by weight of the elastic rubber having a carboxyl group or an acid anhydride group.

The vulcanization accelerator or activator used in the present invention differs depending on what is used as the vulcanization agent. That is,
When sulfur or a sulfur compound is used as the vulcanizing agent, benzothiazoles, benzothiazole sulfenamides,
Examples thereof include dithiocarbamate salts, xanthogens, thioureas, dithiocarbamylsulfenamides and guanidines. When an organic peroxide is used as a vulcanizing agent, ethylene glycol dimethacrylate, butylene glycol dimethacrylate, methacrylates such as trimethylolpropane trimethacrylate as a vulcanization activator, triallyl cyanurate, triallyl isocyanurate, and triallyl isocyanurate. Examples include allyl phosphates, triallylates such as triallyl trimellilate, and metaphenylene dimaleimide.

The blending amount of the vulcanization accelerator or activator is 0 depending on 100 parts by weight of the elastic rubber having a carboxyl group or an acid anhydride group, depending on the required physical properties of the rubber, the vulcanization rate, the type of the vulcanizing agent, and the like. It can be arbitrarily set within the range of 0.5 to 4 parts by weight.

As the softening agent used in the present invention, a general petroleum-based process oil is used. Specifically, it is paraffin oil, naphthene oil, aromatic oil and the like. Further, for oil-resistant acrylic rubber, NBR and the like, low molecular weight plasticizers such as phthalic acid ester, sebacic acid ester, adipic acid ester and phosphoric acid ester can be used. Other various polyester plasticizers, chlorinated polyethylene, etc. can also be used according to the application. The blending amount of the softening agent can be arbitrarily determined in the range of 0 to 150 parts by weight with respect to 100 parts by weight of the elastic rubber having a carboxyl group or an acid anhydride group according to the required rubber physical properties.

In addition, an antioxidant, an antioxidant, an antiozonant, an ultraviolet absorber, a tackifier, a plasticizer and the like may be blended depending on the required performance of the rubber portion.

These raw rubbers, fillers, vulcanizing agents, accelerators, activators, softening agents and other additives are blended in the same manner as in the usual kneading of rubber compositions. That is, generally, a method of blending a raw material rubber, a filler, and a softening agent with a kneader or a roll, and then blending the obtained composition with a vulcanizing agent, an accelerator, an activator, etc. at a low temperature using a roll is used. Used. It goes without saying that the order may be changed slightly depending on the dispersibility of the compounding agent and the risk of scorch.

The epoxy group-containing resin composition used in the present invention is not particularly limited as long as the epoxy group is present in the composition. The method for preparing a resin composition containing an epoxy group includes 1) a method of blending a low molecular weight or a polymer containing an epoxy group with a resin composition, 2) glycidyl methacrylate, 3,4-epoxycyclohexyl methacrylate, 3,4- Dimethyl-4-glycidyloxy-
Examples thereof include a method of bonding an epoxy group-containing unsaturated monomer such as phenylacrylamide by copolymerization or a polymer reaction. It is considered that the epoxy group in this resin composition reacts with the carboxyl group in the rubber to form an ester bond, thereby dramatically improving the interfacial adhesiveness between the two layers.

The epoxy group-containing resin composition used in the present invention must not be deformed in the rubber vulcanization process. The vulcanization temperature of rubber is usually 140-18
Since the temperature is around 0 ° C., the resin composition whose softening temperature or heat distortion temperature is higher than those temperatures is suitable for the purpose of the present invention. Since a general-purpose polymer containing an epoxy group in the molecule generally has a softening temperature of 140 ° C. or less, a polymer having a high softening temperature such as engineering plastic is blended with a polymer containing an epoxy group and the blending thereof. It is practical to control the softening temperature and epoxy content of the composition by ratio. Examples of such engineering plastics include polyamide resin, PBT resin, PET resin, polyarylate resin, polyacetal resin, polycarbonate resin, polysulfone resin, and various plastics reinforced by a filler.

Of course, when the rubber composition can be vulcanized at a low temperature by using a combination of a vulcanizing agent, a vulcanization activator and an auxiliary agent, it may be practically acceptable even if the resin portion is slightly deformed during the vulcanization process of the rubber. Needless to say, there is no problem with plastics having a low softening temperature.

The epoxy group-containing low molecular weight or high molecular weight used in the present invention is specifically bisphenol / epichlorohydrin condensate, halogenated bisphenol /
Epichlorohydrin condensate, resorcinol / epichlorohydrin condensate, 1,1,2,2-tetrakis (hydroxyphenylmethane) / epichlorohydrin condensate,
Novolak epoxy resin, polyalkylene glycol / epichlorohydrin condensate, polyhydric alcohol such as glycerin / epichlorohydrin condensate, epoxidized soybean oil,
Epoxidized diene polymers such as polybutadiene, polyisoprene, polychloroprene, ethylene / glycidyl methacrylate copolymer, styrene / acrylonitrile / glycidyl methacrylate copolymer, ethylene / vinyl acetate / glycidyl methacrylate copolymer, ethylene / methyl methacrylate / Glycidyl methacrylate copolymer, styrene / glycidyl methacrylate copolymer, ethylene / propylene / 3,4-dimethyl-4-glycidylmethoxyphenylacrylamide copolymer, styrene / 3,4-epoxycyclohexyl methacrylate copolymer, etc. containing epoxy Homopolymers or copolymers of unsaturated monomers, vinylcyclohexene dioxide, dicyclopentadiene dioxide, 3 ', 4'-epoxy-
6'-methylcyclohexylmethyl 3,4-epoxy-
Examples thereof include alicyclic epoxy compounds such as 6-methylcyclohexane carbonate. Also, various polymers are combined with epoxy-containing unsaturated monomers such as glycidyl methacrylate, 3,4-epoxycyclohexyl methacrylate, and 3,4-dimethyl-4-glycidyloxyphenyl acrylamide using organic peroxides. Can be used. In either case, it is necessary to have two or more epoxy groups in the molecule.

When blending these epoxy group-containing low-molecular or high-molecular compounds with Engineer-Link plastic, melt blending using a kneader, extruder or the like, or dry blending using a tumbler or the like is an appropriate method depending on the situation. Can be used. However, when a low-molecular epoxy compound is melt-blended with a polymer, it may scatter depending on the melting temperature. Therefore, a high-molecular epoxy compound is desirable for quantitative and uniform blending.

The production of the composite member comprising the above-mentioned resin composition containing an epoxy group and an elastic rubber member having a carboxyl group or an acid anhydride group can be carried out by a one-step or two-step method. .

In the case of the two-step method, a molded product of a resin composition containing an epoxy group, which is produced by press molding, injection molding or extrusion molding, and a carboxyl group or an acid anhydride group mixed with a vulcanizing agent. And the elastic rubber composition having the above are closely contacted and then exposed to a predetermined rubber vulcanizing condition. When the molded body of the resin composition and the elastic rubber composition are combined, the elastic rubber composition may be preformed.

In the case of the two-step injection molding method, it is carried out in the same manner as in the case of manufacturing a two-color injection molded article in two steps. A thermoplastic resin molding is used as the fitting member. The cylinder and screw of the injection molding machine are designed for rubber processing as is known. The device can be preheated to the vulcanization temperature. The optimum co-vulcanization conditions depend on the elastic rubber composition selected, the vulcanization system and the shape of the molded body. Needless to say, the thermal deformation of the resin portion must be taken into consideration. Typical vulcanization temperature range is 12
The vulcanization time is 0 to 200 ° C. and the vulcanization time is 3 to 60 minutes, but it is 1 for reasons such as prevention of deformation and burning of the resin portion and reduction of the vulcanization time.
It is preferable to select at 40 to 180 ° C. for 5 to 30 minutes.

When the combination and the vulcanization are performed according to the two-step extrusion molding method, for example, after the resin composition profile is manufactured in the first step, the rubber composition profile is extruded in the next step, combined and adhered to each other. Vulcanize.

In the case of the one-step injection molding method, it is carried out in the same manner as the one-step two-color injection molding. First, after molding the resin composition,
The elastic rubber composition is injection-molded, the vulcanization temperature is set below the deformation temperature of the resin composition, and pressure is applied for a predetermined time.

[0032]

The method for producing a composite member made of plastic and rubber according to the present invention can omit and shorten the complicated process which has been required to bond the plastic and rubber up to now, and thereby greatly reduces the process. It has become possible to obtain various cost reductions. Further, the resin composition used for this composite member can be easily obtained by blending a commercially available low molecular weight or high molecular weight epoxy resin with various engineering plastics, and the combination can be freely selected according to the application. Have.

[0033]

The present invention will be further described based on the following examples.

Examples 1 to 16 (Preparation of Elastic Rubber Composition) Two kinds of elastic rubber compositions containing a carboxyl group shown in Table 1 were prepared. The rubber, the filler, and the softening agent were kneaded with a kneader, and then the vulcanizing agent, the vulcanization accelerator, and the antioxidant were kneaded at 50 ° C. or lower using a roller.

(Preparation of Resin Composition) Six kinds of resin compositions containing epoxy groups shown in Table 2 were prepared. Nylon 6 manufactured by Ube Industries, Ltd. for engineering plastics
(1013B) and PBT resin (Toughpet N1000) manufactured by Mitsubishi Rayon Co., Ltd. were used. These resins and epoxy-modified polyethylene (Sumitomo Chemical Co., Ltd. ethylene / glycidyl methacrylate copolymer, Bondfast E and 7M) were blended in the ratios shown in Table 2, melt-blended using an extruder and pelletized. did.

(Preparation of adhesion test piece) 25 mm × 50 mm
A × 3 mm plastic piece was molded using each of the fat compositions shown in Table 2. 25mm x 140 pieces of these plastic pieces
It was fitted in a metal frame having a cavity of mm × 3 mm so that a cavity of 25 mm × 40 mm × 3 mm remained in the central part. The elastic rubber composition shown in Table 1 was placed in this cavity and pressed at a predetermined temperature for a predetermined time. The pressing pressure is 500 kgf / cm ² . After the protrusion of rubber such as burr was removed to clarify the interface, it was subjected to a tensile test. The tensile speed was 25 mm / min, and the breaking strength and the elongation were measured. The results are shown in Table 3.

Comparative Examples 1 to 6 Nylon 6 (1013B) manufactured by Ube Industries, Ltd. and PBT resin (Toughpet N1000) manufactured by Mitsubishi Rayon Co., Ltd. were used to mold 25 mm × 50 mm × 3 mm plastic pieces. A plastic / rubber / plastic test piece similar to that in the example was prepared and subjected to a tensile test. The results are shown in Table 3.

[0038]

[Table 1]

[Table 2]

[Table 3]

Claims (5)

[Claims] 1. A composite member in which a member made of a resin composition containing an epoxy group and an elastic rubber member having a vulcanized carboxyl group or an acid anhydride group are bound at an interface. 2. A member made of a resin composition containing an epoxy group, and 50 to 300 parts by weight of a filler and 1 to 10 parts by weight of a vulcanizing agent with respect to 100 parts by weight of an elastic rubber having a carboxyl group or an acid anhydride group. , Vulcanization accelerator or activator 0.5-4
A composite member obtained by binding at the interface with a rubber member obtained by vulcanizing an elastic rubber composition comprising 1 part by weight and a softening agent of 0 to 150 parts by weight. 3. The epoxy group-containing resin composition is a blend of an epoxy group-modified polyolefin and a polyamide and / or polyester.
Composite material. 4. A method for producing a composite member, wherein an elastic rubber composition having a carboxyl group or an acid anhydride group containing a vulcanizing agent is adhered to a member made of a resin composition containing an epoxy group and vulcanized. 5. A member made of a resin composition containing an epoxy group, wherein 50 to 300 parts by weight of a filler and 1 to 10 parts by weight of a vulcanizing agent are added to 100 parts by weight of an elastic rubber having a carboxyl group or an acid anhydride group. , Vulcanization accelerator or activator 0.5-4
A method for producing a composite member, in which an elastic rubber composition comprising 0 part by weight and a softening agent of 0 to 150 parts by weight is adhered and vulcanized.