JPH04244837A - Backing material of panel and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a novel backing material capable of simultaneously conducting the formation of a rib and the formation of a syntactic foam layer by a resin on the surface of a panel when the panel is backed, and manufacture thereof. CONSTITUTION:A backing material is manufactured in such a manner that a sheet at a position corresponding to a rib section is cut out and removed from a sheet composed of the mixture of a foamable material and a thermo-setting resin and said cutting-out section is filled with the thermo-setting resin and formed in a sheet shaped. In the backing material, it is favorable that the cutting-out section is cut out in size larger than an expected rib, non- expandable hollow body particles are combined together with the foamable material, a fiber layer is arranged on the side not bonded with a panel and a separating film is disposed between the foamable material and the fiber layer.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backing material used for lining panels to improve sound insulation, heat insulation, etc., and a method for manufacturing the same.

0002

[Prior Art] So-called sandwich materials are made by bonding a foam core to the back side of a skin material (panel) such as a metal plate or resin plate.
It is often used for weight reduction, sound insulation, heat insulation, etc. As a method for manufacturing such a sandwich material, a method has been developed in which a skin material is formed and then a backing material is attached.

For example, in addition to the most common method of adhering a pre-foamed foam core to the back side of the skin material, there are also methods in which a foamable resin composition is applied or sprayed on the back side of the skin material (for example, JP-A No. 62-33632), a method of creating a foamable resin sheet, adhering it to a skin material, and foaming it (see, for example, JP-A No. 63-159449).

[0004] Materials lined with expanded foam (sandwich materials) have excellent sound insulation and heat insulation properties, and are lightweight overall, and are used as structural materials.
Since the strength of the foam portion is likely to be insufficient, it is necessary to thicken the foam or increase the strength of the foam in particularly necessary portions in order to ensure its usefulness as a structural material.

However, it is difficult to make the foam itself lightweight and strong at the same time, and thickening the foam layer will reduce the volume of the passenger compartment and trunk if, for example, this method is used to make car doors, trunk lids, etc. It turns out. As a solution to this problem, there is a method of attaching ribs to the skin material.For example, as a practical solution,
Examples include the method described in No. 81913. However, with this method, it is necessary to attach ribs to the back side of the skin material, and when making a sandwich material using a lining material sheet, it is necessary to avoid the ribs and separate the lining material, which makes the work complicated. This is not a desirable method as a rational method.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a new backing material that can rationally perform the above-mentioned rib attachment and foam core lining at the same time, as well as a method for industrially manufacturing such a backing material. It is something to do.

[0007]

[Means for Solving the Problems] As a result of intensive research on the above-mentioned problems, the inventor of the present invention has found that the portions to be reinforced with ribs are made substantially only of resin, and the other portions are lined with a material made of foam. With this in mind, we completed the lining material of the present invention.

That is, the present invention provides a sheet of an uncured or semi-cured thermosetting resin containing a foamed material, and the sheet has a plurality of ribs formed at appropriate intervals at positions corresponding to the rib portions. A backing material for a panel characterized in that it has a portion that is substantially made only of an uncured or semi-cured thermosetting resin and does not contain a foamable material in the thickness direction of the sheet, and furthermore, at least It is a backing material for a panel in which a reinforcing fiber layer is laminated on one side and, if necessary, a separation membrane and a thin metal leaf, which will be described later, are laminated.

FIG. 1 is a cross-sectional view showing an example of the structure of such a backing material. This part consists only of synthetic resin.

Further, (3) is a reinforcing fiber layer impregnated with a thermosetting resin, and (4) is a reinforcing fiber layer that is interposed between the above-mentioned inner sheet and the reinforcing fiber layer laminated on the surface, and the foamable material is formed on the surface when foaming. This is a separation membrane designed to prevent lateral movement. (5) is a thin metal layer laminated on the side opposite to the side to be bonded to the panel.

The foamable materials used in the present invention include azo compounds such as azodicarbonamide and azobisisobutyronitrile, paratoluenesulfonyl hydrazide, 4,4
Known organic blowing agents such as hydrazides such as oxybisbenzenesulfonyl hydrazide, nitro compounds such as dinitropentamethylenetetramine, inorganic blowing agents such as sodium bicarbonate, trade name ``Microsphere'' (manufactured by Matsumoto Yushi Pharmaceutical, Dow Chemical Company) ), polyvinylidene chloride thermally expandable particles such as "Expancel" (manufactured by Expancel),
Examples include organic thermally expandable particles such as polystyrene-based expandable particles such as "Eslen HE" (manufactured by Sekisui Plastics Co., Ltd.), and other expandable particles such as acrylic and paraphenylene oxide-based expandable particles. When using a separation membrane to prevent the movement of the foamable material, the organic blowing agent or inorganic blowing agent may be dissolved or mixed with another resin that is difficult to dissolve in the thermosetting resin mainly used and then ground. It is preferable to adopt a method such as using it in the form of particles.

The thermosetting resin used in the present invention is a resin that can adhere or stick to the panel to be lined, hardens near the foaming temperature of the foamable material, and flows at a temperature at which the foamable material foams. As long as this condition is satisfied, a thermoplastic resin can also be used in combination. Examples of such thermosetting resins include unsaturated polyester resins, epoxy resins, vinyl ester resins, and polyurethane resins. The resin can also be supplemented with reinforcing materials, such as short fibers such as milled fibers, whiskers, etc., which may be preferred. Examples of such things are glass fiber, carbon fiber,
Examples include milled fibers and short fibers such as silicon carbide fibers and alumina fibers, and whiskers such as carbon, silicon nitride, silicon carbide, and alumina. Further, exfoliated and crushed mica may be used.

[0013] In the present invention, it is often preferable to use inorganic or organic non-expandable hollow particles in combination with the foamable material, but the hollow particles used in this case include glass balloons, silica balloons, and glass balloons. etc. can be mentioned. Expanded particles of polyvinylidene chloride, such as Expancel DE under the trade name of Expancel, are also used.

The material used as the separation membrane is a foamable material (and the above-mentioned non-expandable hollow particles) that allows liquid resin to pass through.
In addition to fiber materials such as nonwoven fabrics, woven fabrics, and knitters with small openings that do not pass through, porous films and the like can be cited. Generally, the separation membrane material is preferably a material that serves as a reinforcing material in fiber reinforced resin (FRP).

[0015] The reinforcing fiber layer is a reinforcing material and also serves as a passage for the molten resin to move during lining, but depending on the selection of resin, it may be preferable that the reinforcing fiber layer has a coarse mesh. be. The material may be any general reinforcing fiber, such as polyester fibers, especially arylate fibers, nylon fibers, especially aramid fibers, polyolefin fibers, especially organic fibers such as high polymerization degree polyethylene fibers, glass fibers, carbon fibers, alumina fibers, silicon carbide fibers, Examples include inorganic fibers such as silicon nitride fibers and metal fibers, and natural fibers such as cotton and hemp, and glass fibers are usually used.

[0016] Examples of the thin metal sheet include thin sheets of aluminum, magnesium, etc., alloys thereof, copper, and steel, and in most cases, aluminum-based sheets are used.

In the backing material of the present invention, as shown in FIG. 1, a portion consisting essentially only of a thermosetting resin exists at a predetermined position of the sheet and extends in the thickness direction of the sheet. This is formed at a position corresponding to the rim portion, and its arrangement, size, number, etc. may be appropriately selected depending on the shape and size of the backed panel and the mechanical properties required of the panel. In many cases, it is preferable to provide a large number of them at approximately regular intervals.

[0018] This backing material is laminated on the back side of a metal plate, resin plate, etc. that will become the skin material (panel), heated under pressure,
The foamable material is foamed, the thermosetting resin is cured, and the material is bonded to the panel to form a ribbed sandwich material. When this backing material is put into practical use, a problem may arise that after foaming, the thickness of the resin part (rib part) becomes smaller than that of the foam part (foam part). However, this case can be solved by compressing the rib portion from both sides using the pressure caused by foaming to increase its thickness. Furthermore, a fiber layer may be provided on the side opposite to the side to be bonded to the panel so that the resin is moved to the rear of the ribs (to the fiber layer portion) during lining (molding). Furthermore, in order to reduce the difference in thickness between the foamed part and the resin part, it is effective to use non-expandable (non-expandable) hollow particles together with the foamable material. By such means, the amount of expansion of the foamed portion during lining can be suppressed, and even if the degree of compression of the resin portion is reduced, a flat lining portion can be formed.

In the present invention, since there is little problem in covering the side of the rib portion opposite to the side to be bonded to the panel (non-adhesive side) with a foam molding, the foam resin passes through as described above. It is often preferable to provide the fibrous layer on the non-bonded side. When molding a sandwich material using this lining material, it is preferable to cover the lining material with a mold etc. and mold it along with the panel (skin material), and the resin is applied to the mold and the lining along the fiber groups of the fiber layer. move between the bodies of the material. Also,
By utilizing the fact that the thickness of this portion can be changed, it is possible to obtain a sandwich material with a uniform stiffness distribution.

As a method that does not use a mold, it may be preferable to laminate thin metal sheets on the non-adhesive side of the backing material. This thin metal leaf is required to have flexibility as a backing material and rigidity as a support for foamed resin, etc., so it may be preferable to provide bent grooves or the like.

Next, a method for industrially manufacturing the backing material of the present invention as described above will be described in detail.

The backing material of the present invention is produced by forming a mixture of an uncured or semi-cured thermosetting resin and a foamable material into a sheet under conditions that the foamable material does not foam and the resin does not harden. The sheet is manufactured by cutting out portions where rib portions are to be formed at appropriate intervals, filling the cut-out portions with uncured or semi-cured thermosetting resin, and forming an integral sheet.

[0023] At this time, a reinforcing fiber layer impregnated with uncured or semi-cured resin is laminated on at least one side of the partially cut out sheet, so that the resin in the layer is moved to the cut out part. It's okay. Further, the separation layer may be provided on at least one side of the sheet to prevent foamed particles and bubbles from appearing on the surface during lining. When laminating the reinforcing fiber layer, it is preferable to laminate the reinforcing fiber layer on the separation layer as shown in FIG.

Specific embodiments of the method of the present invention include:
For example, a foamable material such as thermally expandable particles is dissolved or dispersed in an uncured or semi-cured thermosetting resin, this mixture is formed into a sheet, and the portions of the sheet that are to be ribs are made larger than the required rib width. After removing the cutout (this ratio is determined from the amount of foaming during molding, etc.), it is laminated with uncured or semi-cured thermosetting resin, or immersed in this resin to impregnate the cutout space with resin. A method is adopted in which a reinforcing fiber cloth or the like and thin metal leaves are laminated as necessary to form a sheet. That is, in this method, first, a foamable material such as thermally expandable particles and a thermosetting resin such as an uncured epoxy resin that is semi-solid at room temperature are mixed uniformly, and then this is pressed at a relatively low temperature. Make it into a sheet. Next, a predetermined rib position and corrected width are determined, and a part of the sheet is cut out using a press or the like. A thermosetting resin is added to this sheet, or a fiber cloth or the like impregnated with the same resin is laminated thereon, and if necessary, a fiber cloth or a thin metal leaf is further laminated thereon, and the sheet is formed into a sheet using, for example, a calender. These operations can be performed continuously.

As another embodiment, in addition to cutting out the portion corresponding to the rib portion, laminating resin sheets, and forming a sheet by calendering, as already mentioned, the portion corresponding to the rib portion may be made of a predetermined metal without a resin injected portion. Another method may be to pour a foamable resin composition into a mold to create a foamable sheet with the missing portions, place the foamable sheet in another mold, and cast resin into the missing portions.

Next, an example of steps for continuously carrying out the method of the present invention will be explained with reference to FIG. Figure 2 is a schematic diagram of the manufacturing process. In Figure 2, (11) is a mixture hopper of expandable material (and non-expandable hollow particles) and thermosetting resin for molding, with an outlet at the bottom. has. (12) is a conveyor belt, (13) is a cutting press for cutting out sheets, (14) is a reinforcing fiber sheet with small openings, (15) is a resin-impregnated bathtub, (16) is another opening (17) is a large reinforcing cloth, (17) is a metal sheet, (18)
(19) indicates the calendar, and (19) indicates the product lining material.

In this step, the mixture containing the foamable material (and non-expandable hollow particles) and the thermosetting molding resin is uniformly distributed from the mixture hopper (11) onto the belt (12). After being lightly pressed into a sheet using a press (not shown), it is cut and cut at predetermined positions using a cutting press (13). The reinforcing fiber sheet (14) is impregnated with a thermosetting resin in a resin-impregnated bath (15), and then laminated on both sides of a sheet of the mixture from which necessary portions have been cut. Furthermore, reinforcing cloth (16) and metal sheet (
17) are laminated, pressed with a calendar (18), and wound up as a backing material (19). Reinforced fiber sheet (1
4) Instead of impregnating resin with resin and laminating it, a resin sheet,
For example, semi-solidified thermosetting resin sheets may be laminated.

In order to form a sandwich material by lining a panel (skin material) made of metal, resin, etc. using the lining material of the present invention manufactured in this way, the lining material is manufactured continuously as shown in the figure. If it is a sheet material that has been made, cut it at an appropriate position to give it the desired size and shape, then glue it to the back of a pre-formed panel (skin material), such as a trunk lid, and heat it to form the backing material. After making the resin flowable and foaming the foamable material, the resin is cured and molded. At this time, remove the metal sheet if necessary.

FIG. 3 shows an example of the use of a backing material according to the invention. The backing material (19) is cut to a predetermined size at a predetermined position with a cutter (20), and the cut material (21
) is adhered or adhered to a skin material (23) of a panel or the like, and then heat-melted and foam-molded in a heating furnace (22). In this way a sandwich material (24) lined with ribbed foam is obtained. (25) in the sandwich material (24) is a rib portion made of resin, and (26)
is the form part.

The basis of this method is to use a foamed resin sheet lining material in which the portions corresponding to the ribs are replaced only with non-foamed resin, but the width of the rib portions of the lining material is smaller than the predetermined width after lining. adding non-expandable hollow particles to the foamed part in order to reduce changes in the rib part (i.e. dents after molding), and molding by placing fiber fabric etc. on the non-adhesive side of the rib part. At times, the foamed resin moves behind the rib portion to reduce the dent in this portion;
In order to transfer only the resin to the rib portion, disposing a separation membrane on at least one surface of the foamed portion that passes only the resin and blocks the foamable material (and non-expandable hollow particles) is adopted as a replenishment technique.

[0031]

[Effects of the Invention] By using the lining material of the present invention as detailed above, the panel can be reinforced with ribs and lined with foam at the same time, and has excellent sound insulation and heat insulation properties, as well as sufficient mechanical properties. It is possible to easily obtain a lightweight molded product having the following properties. Moreover, when a backing material with a separation membrane is used, the resulting lightweight molded product has a bubble-blocking membrane between the skin panel and the lined core, resulting in good adhesion between the layers (Unexamined Japanese Patent Publication No. (See No. 63-246212).

[0032]

EXAMPLES Next, examples will be shown to explain the present invention in more detail. These Examples are intended to illustrate one example of the present invention, and are not intended to limit the present invention. In addition, "parts" in the examples are parts by weight unless otherwise specified.

[0033]

[Example 1] A foamable "Expancel DU461" manufactured by Expansen Co., Ltd. was prepared. This is a fine particle that expands at 100°C. In addition, a non-expandable inorganic hollow balloon MQ28 manufactured by Asahi Glass was prepared.

On the other hand, epoxy resins "Epicoat 1001" and "Epicoat 348" manufactured by Yuka Shell Co., Ltd., phthalic anhydride, and 2-methylimidazole were prepared. A mixture of 70 parts of "Epicoat 1001" and 30 parts of "Epicoat 348" was used as resin A, 100 parts of resin A and 3 parts of phthalic anhydride.
Resin B is a mixture of 0 part of 2-methylimidazole and 1.5 parts of 2-methylimidazole.

In addition, a polyester nonwoven fabric with a small opening "Unicell BT0404" manufactured by Unicell Co., Ltd. and a glass fiber fabric manufactured by Asahi Glass Co., Ltd. were prepared. Larger than the mold.
2 pieces of ``UNICELL'' and 3 pieces of glass fiber fabric to match the mold.
I cut it out.

Melt 100 parts of resin B, add 22 parts of "Expancel 461" to it, and add hollow balloon M made by Asahi Glass.
22 parts of Q38 were added and mixed. This viscous mixture was placed in a mold, leveled, lightly pressed and cooled to form a sheet. This was cut into a predetermined size to fit the mold. Then, using a press cutting machine, 20 rectangular holes of 10 mm x 40 mm were cut out at approximately equal intervals.

The partially cut foamed sheet was placed in a simple mold of the same size as the sheet, and the cut positions were filled with resin B and leveled. A ``unicell'' sheet was added on both sides of this.

Two pieces of glass fiber fabric cut to a predetermined size were immersed in a melt of resin B. Between these “
A prototype backing material was obtained by sandwiching the laminated foam sheet of "UNICELL" and pressing a third sheet of glass fiber fabric cut to the same size and aluminum foil.

Next, warm up the prototype backing material, turn the aluminum foil side outward, and place it on a pre-made aluminum panel (
It was adhered to the skin material) and heated in an oven at 110°C. When it was taken out after one hour, it was confirmed that it was lined with a foam sheet having ribbed portions as expected.

[0040]

[Example 2] All the materials used in Example 1 were prepared. Resin B was prepared and made into a 0.5 mm thick sheet using a press.

On the other hand, in the same manner as in Example 1, resin B, "Expancel 461" and MQ38 were mixed and formed into a sheet. Cut out a part of this at a predetermined position as in Example 1,
Sheets made only of resin B were laminated on both sides of this and melt-molded using a press. The backing material was thus obtained.

[0042] This backing material and an iron plate were stacked and held in a press without applying pressure, and the temperature was raised to 110°C. It was removed after 1 hour and cooled to give a good molding lined with ribbed foam.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of the structure of the lining material of the present invention.

FIG. 2 is a schematic diagram showing an example of a process for continuously manufacturing the backing material of the present invention.

FIG. 3 is a schematic diagram showing an example of the process of lining a panel using the lining material of the present invention.

[Explanation of symbols]

Claims (8)

[Claims] Claim 1: A sheet made of an uncured or semi-cured thermosetting resin containing a foamable material, and the sheet has a substantially uncured or semi-cured resin at appropriate intervals extending through the thickness of the sheet. A panel lining material characterized by having a portion made only of semi-hardened resin and not containing any foamable material. 2. The panel backing material according to claim 1, wherein the thermosetting resin contains non-expandable hollow particles as well as an expandable material. 3. A reinforcing fiber layer impregnated with or not impregnated with the thermosetting resin is laminated on at least one side of the sheet made of an uncured or semi-cured thermosetting resin containing the foamable material. 3. The panel lining material according to claim 1, further comprising a thin metal leaf laminated thereon as required. 4. A mixture of an uncured or semi-cured thermosetting resin and a foamable material is formed into a sheet under conditions that the foamable material does not foam and the resin does not harden, and the sheet is partially cut out. , providing one or more cutouts substantially penetrating the sheet in the thickness direction, and filling each cutout with uncured or semi-cured thermosetting resin to form an integrated sheet. A method for manufacturing a panel lining material characterized by: 5. A mixture of an uncured or semi-cured thermosetting resin and a foamable material is formed into a sheet under conditions that the foamable material does not foam and the thermosetting resin does not harden, and the sheet is partially a reinforcing fiber layer impregnated with an uncured or semi-cured thermosetting resin on at least one side of the sheet, the sheet having one or more cut-outs substantially penetrating the sheet in the thickness direction; , and if necessary, a thin metal leaf is laminated on the reinforcing fiber layer, and then pressurized under conditions that do not completely cure the thermosetting resin to form an integral sheet. Method of manufacturing panel lining material. 6. A mixture of an uncured or semi-cured thermosetting resin and a foamable material is formed into a sheet under conditions that the foamable material does not foam and the thermosetting resin does not harden. 6. A method for manufacturing a panel backing according to claim 5, wherein before or after cutting out the material, it is covered with a separator membrane which is impermeable to the foamable material but permeable to the resin at its foaming temperature. 7. The method for manufacturing a panel backing material according to claim 4, 5 or 6, wherein non-expandable hollow particles are further added to the mixture of uncured or semi-cured thermosetting resin and foamable material. . 8. The method for manufacturing a panel lining material according to claim 4, wherein a reinforcing fiber layer is provided on the side opposite to the surface to be bonded to the panel.