JPH0733029B2 - Insert reaction injection molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a reaction injection molded product comprising a polyurethane main body and a metal insert, the polyurethane main body being formed by reaction injection molding. The invention is particularly suitable for products that are used in environments such as automobile steering wheels, moldings, bumpers, etc. where there are large differences in temperature and temperature, and that require high adhesive strength.

<Prior Art> Taking a steering wheel as an example of the above-mentioned molded product, as shown in FIG. 1, the lower mold 3 with the core metal (insert) 1 set is raised to be combined with the upper mold 5. After closing the mold, a polyurethane material prepared by mixing a polyol component and an isocyanate component with a mixing head is poured into the cavity 7 formed by the mold closing. In this way, the wheel body portion (polyurethane body portion) 9 of the steering wheel is subjected to reaction injection molding. At this time, normally, in order to obtain a large adhesive strength between the wheel body 9 and the core metal 1, a chloroprene rubber (CR) adhesive is applied to the core metal 1 in advance to form the adhesive layer 2. Then, the reaction injection molding was performed.

<Problems to be solved by the invention> However, with CR adhesives, if an attempt is made to always obtain a large adhesive strength, the isocyanate index (NCO index; OH equivalent to 100) of the polyurethane material is set to a high value (usually). , Around 110). However, from the viewpoint of the physical properties of polyurethane (particularly hardness), it is not desirable that a large amount of unreacted isocyanate remains in the polyurethane, and it is necessary to balance the adhesiveness and the physical properties of polyurethane. Therefore, the allowable range of the NCO index (normally NCO index = 110 ± 4) is narrow, and it is necessary to strictly control it, resulting in poor productivity.

<Means for Solving the Problems> The inventors of the present invention have devised an effort to solve the above problems, and as a result, have conceived an insert reaction injection molded article having the following structure.

In a reaction injection-molded product comprising a polyurethane main body and a metal insert, the polyurethane main body being formed by reaction injection molding, wherein the polyurethane main body and the metal insert are silane-based, titanium-based, aluminum-based, zirconium-based It is characterized by being integrated via an adhesive layer of an isocyanate-based adhesive to which at least one coupling agent selected from the above is added.

<Detailed Description of Configuration> Hereinafter, each configuration of the above means will be described in detail.

(1) The polyurethane main body is formed by reaction injection molding a polyol component and a polyisocyanate component in the range of NCO index = 100 to 110. At this time, the other molding conditions are
Usually, discharge amount: 100-300 g / sec, discharge pressure: 50-200 kgf / cm ² ,
Material temperature: 20-40 ° C.

The polyol component and the polyisocyanate component are not particularly limited as long as they can be used for reaction injection molding.
Usually, a polyether-based and / or polymer-polyol-based polyol component and a polyisocyanate component
A 4,4'-diphenylmethane diisocyanate (MDI) system is used. At this time, a catalyst is added to the polyol component, and further, agents such as a foaming agent, an antioxidant and a pigment are appropriately added.

(2) The material of the metal insert is usually steel or aluminum. Here, it is desirable that the insert be subjected to pretreatment such as degreasing treatment and blasting treatment before the adhesive is applied.

(3) The isocyanate adhesive may be either a two-component polyurethane adhesive or a one-component polyisocyanate prepolymer / polyisocyanate adhesive,
From the viewpoint of workability, the one-pack type is preferable.

The polyisocyanate used above may be aliphatic, alicyclic or aromatic. Specifically, in addition to the above MDI type, tolylene diisocyanate (TD
I), xylene diisocyanate (XDI), hexahydroxy diisocyanate (H6-XDI), 4,4'-diphenyl ether diisocyanate, 1,5-naphthalene diisocyanate, hexamethylene diisocyanate, tetraisocyanate silane and the like.

The polyol used is appropriately selected from polyether polyol, polyhydric alcohol, polyhydric phenol, polyester polyol, acrylic polyol, castor oil derivative, tall oil derivative and the like.

(4) At least one coupling agent selected from silane-based, titanium-based, aluminum-based, and zirconium-based adhesives is added to the isocyanate-based adhesive. The amount of the coupling agent added to 100 parts by weight of the adhesive polymer is different depending on the type of the adhesive, the coupling agent, the insert metal and the polyurethane, but is usually 0.
1 to 50 parts by weight.

The respective coupling agents are exemplified below.

Silane-based; γ-chloropropyltrimethoxysilane, γ-chloropropylmethyldichlorosilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, γ- (2-amino Ethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane Hydrochloride, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, vinyltriacetoxysilane, γ-chloropyrtrimethoxysilane, hexamethyldisilazane, γ-anilinopropyltrimethoxysilane Silane, vinyltrimethoxysilane, octadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium chloride, γ-mercaptopropylmethyldimethoxysilane, trimethylsilyl isocyanate, dimethylsilyl isocyanate, methylsilyl isocyanate, vinylsilyl triisocyanate, phenylsilyltri Isocyanate, tetraisocyanate silane, ethoxysilane triisocyanate, vinyltrichlorosilane, vinyltris (βmethoxyethoxy) silane, vinyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-ureidopropyltriethoxysilane , 1,3-bis (γ-aminopropyl) -1,1,3,3-tetradimethylsiloxane.

Titanium-based; isopropyl triisostearoyl titanate, isopropyl tridecylbenzene sulfonyl titanate, isopropyl tris (dioctyl pyrophosphate)
Titanate, tetraisopropylbis (dioctylphosphite) titanate, tetraoctylbis (ditridecylphosphite) titanate, tetra (2,2-diallyloxymethyl-1-butyl) bis (di-tridecyl) phosphite titanate, bis (dioctyl) Pyrophosphate) oxyacetate titanate, bis (dioctyl pyrophosphate) ethylene titanate, isopropyl trioctainor titanate, isopropyl dimethacryl isostearoyl titanate, isopropyl isostearoyl diacrylic titanate, isopropyl tri (dioctyl phosphate) titanate, isopropyl tricumylf Enil titanate, isopropyl tri (N-aminoethyl-aminoethyl)
Titanate, dicumylphenyloxyacetate titanate, diisostearoyl ethylene titanate, aluminum-based; acetoethoxy aluminum diisopropinate, diisopropoxyaluminum ethylacetoacetate, zirconium-based: zirconium butyrate, zirconium acetylacetonate, acetylacetone zirconium butyrate, Zirconium lactate, zirconium stearate butyrate, zircoaluminates represented by the following chemical formula.

(5) The above-mentioned isocyanate adhesive is adjusted to have an appropriate viscosity with an organic solvent and applied to a metal insert to form an adhesive layer. Here, examples of the organic solvent used include tetrahydrofuran, trichloroenter, methine chloride, toluene and the like. Further, the application means is not particularly limited, and may be dipping, brushing, spraying or the like.
Further, a filler, a colorant, a catalyst for reaction injection molding and the like may be added to the above-mentioned isocyanate-based adhesive, if necessary.

<Operations and Effects of the Invention> The insert reaction injection-molded product of the present invention is, as described above, a reaction injection-molded product comprising a polyurethane main body and a metal insert, the polyurethane main body being formed by reaction injection molding. Polyurethane body and metal insert are made of silane-based / titanium-based / aluminum-based
Through the adhesive layer of the isocyanate-based adhesive to which at least one coupling agent selected from zirconium is added, by being integrated, the NCO index is set high, as shown in the examples below. It is possible to obtain a high adhesive strength between the polyurethane main body and the metal insert even without doing so. Therefore, in insert reaction injection molding, it is not necessary to strictly control the NCO index and productivity is improved.

<Example> An adhesive of each prescription shown in Table 2 was applied to a steel plate (100 x 150 x 0.7 m
m) on one side with a brush (dry film thickness: 20 μm) to prepare two inserts each. The inserts thus prepared are set in the mold cavity (400 × 400 × 5 mm) two by two, and then Table 1 is shown. The polyurethane material having the formulation shown in 1 was injected into the mold according to the reaction injection molding method.

Two test pieces were prepared from each of the molded articles of the respective Examples and Comparative Examples thus obtained, and 180 ° peel strength (pulling speed: 50
mm / min) was measured at room temperature and 60 ° C atmosphere. From Table 3 showing the results, it can be seen that, in each of the examples, even when the NCO index is set to 100, a large adhesive strength is exhibited (most of the adherend destruction of the polyurethane main body). On the other hand, in the comparative example using the CR adhesive, when the NCO index was 100, peeling occurred with a small force.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a steering wheel molding die, which is an example of an insert reaction injection-molded article of the present invention, when molding is completed. 1 ... Core metal (insert), 2 ... Adhesive layer, 9 ... Wheel body (polyurethane body).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinji Shinji Kasuga-mura, Nishiichi Kasugai-gun, Aichi 1 Ochiai, Nagahata, Toyoda Gosei Co., Ltd.

Claims (1)

[Claims] 1. A reaction injection molded product comprising a polyurethane main body and a metal insert, wherein the polyurethane main body is formed by reaction injection molding, wherein the polyurethane main body and the metal insert are silane-based titanium. An insert-reaction injection-molded article characterized by being integrated through an adhesive layer made of an isocyanate-based adhesive to which at least one coupling agent selected from the group consisting of aluminum, zirconium and aluminum.