JPH10202673A - Injection method for two component type foamed urethane composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the leakage of an injected material from an injection hole to the outside by backflow by mounting a shielding plate for the injection hold to be opened and closed freely on the inner face side of a structure to be filled when a two-component type foamed urethane composition is injected into the injection hole of the structure to be filled. SOLUTION: When a two-component type foamed urethane composition is injected into an injection hole 2 of a structure 1 to be filled, a shielding plate 3 for the injection hole 2 is mounted on the inner face side of the structure 1 to be filled in the arrow direction to be opened and closed freely by using, for example, a hinge 4. At that time, a foamed material is jetted while an end jet opening of a mixing head is inserted into or brought into contact with the injection hole 2, and when the shielding plate 3 is lifted up above an mark, injection is completed and the jet operation is discontinued. Or the end jet opening of the mixing head is removed and the shielding plate 3 is closed to prevent the backflow of a foam cured material. The frequency of leakage of an injected material from the injection hole to the outside generated by the backflow following the foam curing can be reduced by the arrangement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for injecting a two-part foamable urethane composition, and more particularly to a method for injecting a two-part foamable urethane composition capable of foaming and curing at room temperature to form a urethane foam. And an injection method for preventing an injectate from leaking out of an injection port due to backflow.

[0002]

2. Description of the Related Art A two-pack type foamable urethane composition is a two-pack type of a so-called polyol main agent and a polyisocyanate curing agent (comprising a foaming agent on the main agent side).
By mixing and injecting two liquids at room temperature,
Immediately foamed and cured to form urethane foam. By the way, in recent years, in the automobile industry, it has been demanded to secure the rigidity of the entire vehicle body and to improve the soundproofness of a living space in order to enhance vehicle safety. Among them, the parts to which many loads such as impacts are applied, for example, the belt anchor of the seat belt device is attached, and the center pillar having a closed cross-sectional structure and the rigidity of the front pillar having the closed cross-sectional structure of the front vehicle body are improved. It is desired to provide soundproofing. For example, a technique of using the above-described two-part foamable urethane composition and filling a foamed and hardened urethane foam in the closed cross section of these vehicle body pillars has been studied.

However, in this technique, since the two-part mixture is injected in a fluidized state, the injected substance often leaks out of the injection port due to backflow accompanying foam hardening. The appearance will be hindered.

[0004]

Means for Solving the Problems Accordingly, the present inventors have:
Not only in the closed cross-section portion of such a vehicle body pillar, after extensive research was conducted to solve the problem of backflow leakage when the two-part foamable urethane composition is injected into the inlet of the structure to be filled widely, The inventor has found that the intended purpose can be achieved by applying a specific device to the inlet or its vicinity, and has completed the present invention.

That is, the present invention relates to a method for injecting a two-part foamable urethane composition into an inlet of a structure to be filled and filling the urethane foam by foaming and curing. In order to prevent leakage from the inlet to the outside, i) whether a shield plate for the inlet is attached to the inner surface side of the structure to be filled so as to be openable and closable; Or iii) injecting the two-part foamable urethane composition by installing a check valve in the inlet, which allows only one-way fluid flow, to form a two-part foam. It is intended to provide a method for injecting a water-soluble urethane composition.

The type of the two-part foamable urethane composition to be used in the present invention is not particularly limited as long as it can be foamed and cured at room temperature, and any type can be used. Specifically, a polyol main agent [preferably a polyether polyol obtained by adding an alkylene oxide to an active hydrogen-containing compound such as polyhydric alcohol, bisphenols, and various amines] and a polyisocyanate curing agent [aromatic poly- Isocyanate, aliphatic or cycloaliphatic polyisocyanate, araliphatic polyisocyanate, various modified products thereof, urethane prepolymer containing terminal NCO group obtained by reaction of polyols with excess polyisocyanate compound, etc.] And a blowing agent (water, a pyrolytic chemical blowing agent (azodicarbodiamide, p, p'-oxybisbenzenesulfonylhydrazide, etc.), a pyrolytic inorganic blowing agent (sodium hydrogen carbonate, etc.) , Heat-expandable micro-balloons (low boiling such as pentane, heptane, etc. Solvent-encapsulated)), and if necessary, a reaction catalyst, foam stabilizer, colorant, plasticizer, filler, flame retardant, antioxidant, antioxidant, etc. Are exemplified.
In particular, it is preferable to blend the foamed cured product so as to be hard.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for injecting a two-part foamable urethane composition (hereinafter referred to as a foamed material) according to the present invention will be described in detail with reference to the drawings. Such an injection method of the present invention comprises:
The purpose of the injection is to prevent backflow leakage of the injected substance, and to achieve the object, the invention is characterized by devising as shown in FIGS. i) In FIG. 1, a shielding plate 3 for an inlet 2 is attached to the inner surface side of the structure 1 to be filled so as to be openable and closable in the direction of the arrow, for example, by a hinge 4. In this case, if the foaming material is sprayed while inserting or contacting the tip discharge port (not shown) of the mixing head to the injection port 2, the shielding plate 3 is lifted above the arrow, but the injection is completed and the injection is stopped. When stopped or when the discharge port at the tip of the mixing head is taken out, the shielding plate 3 is closed to prevent backflow of the foamed cured product. ii) In the case of FIG. 2, (A) (plan view) and (B)
A rubber molded body 6 having a cut portion (for example, a cross cut with an X mark) 5 that can be opened and closed freely (see a front view) is fitted into the injection port 2. That is, if the foaming material is injected by inserting or contacting the tip discharge port of the mixing head to the cut portion 5 of the rubber molded body 6, the cut portion is held in a sealed state by the elastic force of the rubber molded body. The leakage of the foamed cured product to the outside is prevented. iii) As a further improvement, a check valve 7 shown in FIG. In this case, the foam material from the mixing head is
When the injection is stopped, the valve 8 returns to the original closed position, and the backflow is completely prevented.

[0008]

Next, the present invention will be described more specifically with reference to examples. Example 1 A test box 11 having a size of 50 × 50 × 300 mm shown in FIG. 4 was prepared, and an inlet 12 having a diameter of 20 mm was provided on the front wall thereof.
Further, a partition plate 13 of 50 × 46 mm and a partition plate 14 of 50 × 46 mm are provided in the positions shown in the drawing. In addition, as a foaming material, the main agent [polyether polyol (Sanyo Chemical Industries, Ltd.)
50 parts (parts by weight, hereinafter the same), 0.1 part of water and 1 part of a reaction catalyst] and a curing agent (crude MD)
I) A two-part foamable urethane composition consisting of 50 parts is used. Next, a rubber molded body (outside diameter: 20 mm, inside diameter: 15 mm) provided with a cross cut with an X mark was fitted into the injection port 12, and a mixing head (manufactured by Toho Machine Industry Co., Ltd., S
When 200 g of the foamed material was injected through the tip discharge port having a diameter of P-205 (diameter: 8 mmφ), only 0.5 g of leakage was observed. On the other hand, when the same injection was carried out without using the rubber molded body, there was a leakage of 26 g.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a state where a shielding plate for an inlet is attached to an inner surface side of a structure to be filled.

FIG. 2 shows an example of a rubber molded body having a cut portion that can be opened and closed freely, (A) is a plan view, and (B) is a front view.

FIG. 3 is a schematic diagram illustrating an example of a check valve.

FIG. 4 is a perspective view showing a test box (filled structure) used in the example.

[Explanation of symbols]

 1: Structure to be filled 2: Injection port 3: Shield plate 5: Cut part (cross cut) that can be opened and closed freely 6: Rubber molded body 7: Check valve

Claims (1)

[Claims] 1. A method for injecting a two-part foamable urethane composition into an inlet of a structure to be filled and filling the urethane foam by foaming and curing, wherein the injected material flows out of the inlet through backflow during the injection. In order to prevent leakage, i) whether a shield plate for an inlet is openably and closably mounted on the inner surface side of the structure to be filled; ii) a rubber molded body having a cut portion which can be opened and closed at the inlet. Or iii) by injecting the two-part foamable urethane composition into the inlet by installing a check valve that allows only one-way fluid flow, characterized in that the two-part foamable urethane composition is injected. Injection method.