JPS63252732A - Rigid urethane form laminate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention 11 Fields of Use of the Invention The present invention not only has bending and impact strength equivalent to glass fiber reinforcement, but also has extremely superior molding workability and safety. This invention relates to a rigid urethane foam laminate that can be used for automotive molded ceiling materials and door panels that have a complex curved surface structure.

Conventional technology Rigid urethane foam laminate products that use mats, cloth, etc. made of inorganic fibers such as glass fibers as reinforcing materials have been used for a long time. Deterioration of the working environment due to scattering, adhesion to clothes, etc.; - Occurrence of defective products such as wrinkles in curved structures and deep drawing parts during molding; - Damage to cutter blades when trimming product ends; - Due to the weight of the inorganic fiber itself. There were drawbacks such as an increase in product weight.

Problems to be Solved by the Invention The present invention has the same bending and impact strength as conventional hard urethane foam laminates using inorganic fibers such as glass fibers as reinforcing materials, and also uses inorganic fibers listed in I. One object of the present invention is to provide a new rigid urethane laminate that solves the drawbacks of conventional urethane laminates.

Means for Solving the Problems The rigid urethane foam laminate of the present invention uses a woven fabric, knitted fabric, or net made of thermoplastic resin as a reinforcing material.

The thermoplastic resin material used in the present invention is preferably a resin that has high tensile strength and elastic modulus at room temperature or the temperature range in which the molded product is normally used, and which softens slightly in the temperature range for forming the laminate.

For example, highly oriented polyethylene, polypropylene, polyolefin resins such as ethylene/vinyl acetate copolymers, polyamide resins such as nylon 6, 66 nylon, and 12 nylon, polyester, polystyrene, polyurethane, and other product usage temperature ranges. Any thermoplastic resin having strong tensile strength can be used as the material for the reinforcing material of the present invention.

As a reinforcing material, these thermoplastic resin materials are formed into a fibrous or thin tape shape and woven into a single weave.

Alternatively, a woven fabric, a knitted fabric, or a net fused into a sheet is used, but a non-woven fabric can also be used.

It is desirable that the sheet-like woven fabric, knitted fabric, or net made of such a resin be capable of adhering well to the hard urethane foam.

The attachment mode may be either physical or chemical, but it is better if the synergistic effect between them is exhibited.

In other words, in general, rigid urethane foam has a strong chemical affinity to polyamide resins, polyester resins, etc. and chemically adheres (adheses) well, but it has a weak chemical affinity to polyolefin resins such as polyethylene and is not suitable. Good chemical adhesion (adhesion) cannot be expected unless appropriate primer treatment or other measures are taken.

However, in sheet-like woven fabrics, knitted fabrics, or nets, there are points where fibers or thin tapes intersect, and the resin of the hard urethane foam invades in the gap between the intersection points. However, adhesion occurs due to a phenomenon in which a portion of the resin oozes out onto the back side of the reinforcing material, a so-called anchoring effect, but this physical adhesion force also provides sufficient effectiveness as a reinforcing material.

Specifically, even in the case of polyethylene resin, which has poor chemical adhesion to hard urethane foam, we can use its woven fabric, knitted fabric, or netted fabric as a reinforcing material, and then pour the hard urethane foam cream on top of it. The integrally molded laminate is
The urethane resin penetrates uniformly into the interior of the woven fabric, knitted fabric, or net, giving it a good appearance and maintaining good adhesion.In terms of strength, it is a rigid laminate with a bending strength comparable to that between glass fiber reinforcements. becomes.

Needless to say, the reason why reinforcing materials are used in the form of sheets such as woven fabrics, knitted fabrics, or nets is that the anchoring effect enhances the adhesion and enhances the reinforcing effect. The flat plate structure must ensure sufficient rigidity in both the longitudinal and lateral directions, and there must be no anisotropy in strength. For this purpose, it is desirable to use a cloth with an isotropic texture such as plain weave or twill weave, or a net as a reinforcing material.

In addition, in the case of cloth, various structures can be considered depending on the purpose, but when used in the present invention, which aims to obtain the maximum reinforcing effect with light weight, the cloth should be as thin as possible and tightly woven. is recommended.

Specifically, it is preferable to use a tightly woven material made from a fiber or thin tape made of thermoplastic resin and having a diameter or thickness of about 10 to 30 g.

The use of such fabrics also produces effects that cannot be obtained with reticulated sheets or conventional glass fiber mats. In other words, even if the hard urethane foam cream is poured directly onto the cloth, the cream will not seep out from the grains of the cloth and stain the conveyor or mold. Conventionally, to prevent the cream from seeping out, a non-woven cloth was placed under the mat to prevent the conveyor, mold, etc. from getting dirty, but by using a tightly woven cloth, this is no longer necessary and is cost-effective. becomes.

Next, a detailed explanation will be given using an example of actual production of a hard foam laminate.

Examples 1 to 3 and Comparative Examples 1 and 2 I (hereinafter referred to as PP Pour the hard foam foaming cream of the composition shown in Table 1 onto the foam (called a cloth), and immediately place the same PP cloth on the foam in a manner similar to sandwiching the foam cream, and place the same PP cloth on the foam to a height of 8 mm.
Pressing was performed with a thick spacer attached.

Table 1 The pressing temperature at this time is preferably preheated to a temperature (50°C to 70°C) that does not inhibit hard foam hardening and cell formation.

After the form hardens, take out the molded plate from the press ・II'
A plate-shaped molded product of a hard urethane foam laminate reinforced with PP cloth on both sides was obtained.

In a similar manner, a plate-shaped molded product of a hard urethane foam laminate reinforced on both sides with polyethylene resin cloth (PE cloth) and 6-9 cloth, and a hard urethane foam laminate reinforced on both sides with glass fiber mat + nonwoven fabric as a comparative example. A plate-shaped molded product and a rigid urethane foam plate-shaped molded product without using reinforcing material were manufactured.

In the bending strength test, a load was applied to the center of a sample of Ill 50 mm (pressure between fulcrums fi 100 mm) at room temperature.

Bending strength at yield point K g / 5 cm ml)
and initial bending slope (K g/5 cm m m
m) was measured.

The measurement results are shown in Table 2.

Also, immediately after forming the laminate, the internal rigid form is still 11T.
+) 31! At a certain point, the laminate is heated at 120°C using a mold l having a curved surface structure as shown in the 11th view in Figure 1 and the cross-sectional view taken along the line X-X in Figure 1 in Figure 2. Table 3 shows the results of examining press formability.

Table 3 Effects of the Invention Rigid urethane foam laminate products that use conventionally used mats, cloths, etc. made of inorganic fibers such as glass fibers as reinforcing materials are free from the following problems: Deterioration of the working environment due to ■ Occurrence of defective products such as wrinkles in the curved structure part of the molding surface and deep drawing part, ■ Damage to the cutter blade when trimming the end of the product, ■ Increase in product weight due to the weight of the inorganic fiber itself, As mentioned above, problems ① and ② in 1-1 can be solved by not using inorganic fibers, and ③ can be solved by not using inorganic fibers, and ② can be solved by using a thermoplastic resin sheet that has a property of softening slightly at the special molding temperature. By using this, it is possible to prevent molding wrinkles that tend to occur in complex curved structures and deep drawn parts. Furthermore, regarding (2), the weight increase due to the use of the reinforcing material can be reduced by using a woven fabric, knitted fabric, or net made of a thermoplastic resin with a low specific gravity as the reinforcing material.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a mold for a deep-drawn product using the hard urethane foam laminate of the present invention, and FIG. 2 is a cross-sectional view taken along the line xx in FIG. 1.

Claims (1)

[Claims] 1. A rigid urethane foam laminate using a woven fabric, knitted fabric, or net made of thermoplastic resin as a reinforcing material. 2. The rigid urethane foam laminate according to claim 1, which is integrally molded with a rigid urethane foam with a woven fabric, knitted fabric, or net made of thermoplastic resin disposed on the surface.