JP3256916B2 - Steel sheet reinforcement sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel sheet reinforcing sheet which is used by sticking to a steel sheet of various production machines, transportation machines and industrial machines.

[0002]

2. Description of the Related Art In the case of automobiles, the thickness of an automobile steel sheet currently used is generally 0.65 to 0.8 mm due to reduction in weight and progress of steel sheet strength. Although the structural strength of the steel sheet is sufficient, the steel sheet part with a certain area or more is easily deformed by external stress, so by attaching a steel sheet reinforcement to the inside that is not visible from the outside, Prevents steel plate deformation. These reinforcing materials are mixed and kneaded by mixing and kneading the appropriate fillers and additives with a synthetic resin-based material such as an alkyd resin, an epoxy resin, an acrylic resin, a urethane resin, and a urea resin, and a curing agent. The steel plate is reinforced by processing into a size and a shape, attaching to a steel plate reinforcing portion, and thermosetting under predetermined conditions.

[0003] However, in order to obtain a desired reinforcing effect, a reinforcing material having a considerable thickness is required, and the weight increase contradicts the demand for lighter weight for improving the fuel efficiency of automobiles. Moreover, since the above-mentioned resin composition is generally expensive, at present, there is a demand for a more inexpensive, lightweight, and reinforcing sheet having a steel sheet reinforcing effect.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to develop a steel sheet reinforced sheet which contributes to a reduction in the weight of a vehicle by reducing the weight of the sheet itself and has a high price-performance ratio.

[0005]

Means for Solving the Problems In order to solve the above problems, the present inventors have made intensive studies and as a result, have found that a steel sheet comprising a constraining layer and a foamed resin layer comprising a combination of a specific rubber and resin elastomer and other components. It has been found that a reinforcing sheet can be made extremely light and a steel sheet reinforcing sheet having a high price / performance ratio can be realized. That is, the present invention resides in the following.

A steel sheet reinforcing sheet comprising a constraining layer and a foamed resin layer, wherein the resin layer before foaming of the foamed resin layer comprises (a) a rubber having a number average molecular weight of 500 to 20,000,
(B) a mixture comprising 95 to 5% by weight of at least one selected from thermoplastic elastomers [(a)
+ (B)] 100 parts by weight, (c) inorganic filler 5
(D) 1 to 200 parts by weight of a tackifier (e) 0 to 200 parts by weight of a softener (f) 1 to 100 parts of a crosslinking agent
Part by weight (g) A reinforcing sheet for a steel sheet, characterized in that 1 to 100 parts by weight of a foaming agent is blended. Preferably, the constraining layer is any one of glass cloth, carbon fiber, organic fiber nonwoven fabric, and metal foil. The steel sheet reinforcing sheet described above, comprising at least one or more materials selected from the group consisting of:

The rubber of the component (a) used in the present invention includes polybutadiene rubber, 1,2-polybutadiene rubber, styrene butadiene rubber, acrylonitrile butadiene rubber, polyisoprene rubber, chloroprene rubber, and isobutylene-isoprene rubber. And the like. Especially -OH, -COOH, -N
Rubbers having functional groups such as H ₂ , —NCO, and —CH ＝ CH ₂ are exemplified. In particular, polybutadiene rubber, styrene butadiene rubber, and isobutylene-isoprene rubber are recommended. Its number average molecular weight is from 500 to 20,000, preferably from 1,000 to 10,000. Number average molecular weight of 50
If it is less than 0, the adhesive strength to the oil-treated steel sheet may decrease. If it exceeds 20,000, the shape following property may deteriorate. The compounding amount of these rubber components is 5
When the amount of the rubber component is 95% by weight, preferably 30 to 90% by weight, and the compounding amount of the rubber component is less than 5% by weight, the adhesiveness and the shape following ability are reduced. If the content exceeds 95% by weight, the viscosity of the composition before crosslinking decreases, and the adhesive strength to the oil-treated steel sheet decreases.

The thermoplastic elastomer (b) used in the present invention includes 1,2-polybutadiene, an ethylene-vinyl acetate copolymer, an ethylene-ethyl acrylate copolymer, an aromatic vinyl compound and a conjugated diene compound. And hydrogenated products thereof, ionomers and carboxy-modified polyolefins. An elastomer obtained by using an epoxy resin, a polyisocyanate, or the like in combination with the thermoplastic elastomer can also be used. Of the above, preferred are 1,2-polybutadiene, a copolymer of an aromatic vinyl compound and a conjugated diene compound, particularly an acid-modified block copolymer and a polyolefin, and an epoxy resin and a polyisocyanate blended with these. Things.
As 1,2-polybutadiene, the 1,2-bond content is 7
0% or more, preferably 85% or more, and those having a crystallinity of 5% or more, preferably 10 to 40% are recommended. In order to obtain kneading processability and cross-linking foaming property, the molecular weight of the thermoplastic elastomer is [η] (toluene 30
C) is preferably 0.5 dI / gr or more.

The inorganic filler of component (c) used in the present invention includes pigments such as calcium carbonate, barium sulfate, magnesium hydroxide, mica, talc, clay, silicic acid, titanium oxide, carbon black, and the like. fiber,
A fibrous filler such as cotton flock can be used. As the compounding amount of the inorganic filler, the above [(a) + (b)]
It is 5 to 1000 parts by weight, preferably 50 to 800 parts by weight, based on 100 parts by weight of the components. If the compounding amount is less than 5 parts by weight, the kneading property is poor and the whole price increases, which is disadvantageous in cost. On the other hand, when the amount is more than 1000 parts by weight, the adhesiveness and the strength are reduced.

Examples of the tackifier (d) used in the present invention include rosin resins, terpene resins, coumarone indene resins, and aliphatic and aromatic petroleum resins. As the amount of the tackifier, the above [(a) +
(B)] It is 1 to 200 parts by weight based on 100 parts by weight of the component. If the amount is less than 1 part by weight, the adhesiveness to the steel sheet and the constraining layer may decrease, while if the amount exceeds 200 parts by weight, the strength is reduced.

As the softener of the component (e) used in the present invention, mineral oil-based rubber softeners generally called process oils and extender oils can be mentioned. From the viewpoint of compatibility with the other components, naphthene-based and aromatic-based ones are preferred. Other, atactic polypropylene,
Bituminous substances such as asphalt can be exemplified. These (e)
The amount of the component is as follows: [(a) + (b)] component 1
0 to 200 parts by weight, preferably 10 to 100 parts by weight
１５０150 parts by weight. If the amount is more than 200 parts by weight, the kneading processability is significantly reduced.

The crosslinking agent of component (f) used in the present invention may be sulfur or a combination of a compound capable of generating sulfur upon heating and a vulcanization accelerator, organic peroxides, isocyanate compounds, amine compounds and the like. No. A method of crosslinking by ultraviolet rays, electron beams, X-rays or the like can also be used. Common sulfur such as powdered sulfur and colloidal sulfur can be used as the sulfur, and tetramethylthiuram disulfide, tetraethylthiuram disulfide and the like can be exemplified as the compound that generates sulfur by heating. The compounding amount of the crosslinking agent of the component (f) is 1 to 100 parts by weight, preferably 3 to 30 parts by weight based on 100 parts by weight of the component [(a) + (b)]. If the amount is less than 1 part by weight, the degree of crosslinking is insufficient, and it is difficult to obtain reinforcing performance. If the amount is more than 100 parts by weight, the composition becomes brittle and is inferior in practical use.

As the foaming agent (g) used in the present invention, known inorganic or organic foaming agents can be used.
Specific examples thereof include sodium bicarbonate, ammonium bicarbonate, sodium carbonate, ammonium carbonate, azodicarbonamide, dinitrosopentamethylenetetramine,
Examples thereof include dinitrosoterephthalamide, azobusisobutyronitrile, barium azodicarboxylate, sulfonylhydrazide, and toluenesulfonylhydrazide. It can also be used in combination with a foaming aid such as urea or a urea derivative. Of the above, preferred is a combination of each of azodicarbonamide and dinitrosopentamethylenetetramine or a combination thereof with a foaming aid such as urea and a urea derivative. The amount of the foaming agent of the component (g) is from 1 to 10 based on 100 parts by weight of the component (a) + (b).
0 parts by weight, preferably 5 to 70 parts by weight. Particularly preferred is 10 to 50 parts by weight. If the amount is less than 1 part by weight, it is difficult to obtain a desired foaming effect. If the amount exceeds 100 parts by weight, a good appearance may not be obtained due to the gas generated from the foaming agent.

As the constraining layer to be laminated on the foamed resin layer of the present invention, a material which is as light as possible, is a thin film, can impart toughness to the foamed resin layer, and is easily adhered and integrated with the foamed resin layer is preferable. Specific examples include glass cloth, carbon fiber, organic synthetic resin fiber nonwoven fabric, aluminum and steel, and metal foils such as alloys of various metals. Among them, glass cloth and aluminum foil are particularly preferable in consideration of cost, weight, adhesion and strength.

In order to produce the resin layer in the present invention, the above-mentioned various compounds are mixed with a dissolver, a Banbury mixer,
It is manufactured by dispersing and kneading with a conventionally known mixing and dispersing machine such as a planetary mixer, an open kneader, and a vacuum kneader, and then processing it into a sheet by a processing machine such as a calendar roll or an extruder. The steel sheet reinforcing sheet including the constraining layer and the foamed resin layer can be manufactured by laminating and bonding the resin layer and the constraining layer obtained as described above, bonding the resin layer to a steel sheet, and then heating and foaming the resin layer. In advance, the resin layer may be heated and foamed, and the obtained foamed resin layer and the constraining layer may be laminated and bonded. The heating and foaming of the resin layer is possible before and after the application to the steel sheet. Since the resin layer before the heating and foaming has a strong adhesive force, a reinforcing sheet can be obtained only by using the adhesive force and pressing the laminate. Pressure bonding by a mechanical means such as a roller may be used. It is preferable to attach a release paper to the side of the resin layer or the foamed resin layer on which the constraining layer is not laminated before attaching the steel sheet, in consideration of the convenience in attaching the steel sheet to the steel sheet.

[0016]

The following examples are provided to provide a more detailed understanding of the present invention. As a matter of course, the present invention is not limited only to the following examples.

Example 1 40 parts by weight of a carboxy-modified liquid polybutadiene having a number average molecular weight of 2000 and 1,2 polybutadiene (JSR®)
B: manufactured by Nippon Synthetic Rubber Co., Ltd.) 150 parts by weight of calcium carbonate, 50 parts by weight of an aliphatic petroleum resin, 10 parts by weight of process oil, 10 parts by weight of sulfur, vulcanization with respect to 100 parts by weight in total of 60 parts by weight 5 parts by weight of an accelerator and 5 parts by weight of a foaming agent were mixed and kneaded by an open kneader, and a resin layer having a thickness of 0.6 mm was formed by a calender roll. In this resin layer,
Attach a glass cloth of 0.2 mm thickness as a constraining layer,
Release paper was stuck on one side. The release paper was peeled off, affixed to a rectangular dull steel plate having a thickness of 0.8 mm, and heated at 180 ° C. for 20 minutes to foam and thermally cure the resin layer, and adhere to the steel plate.

Example 2 Mixing and kneading were carried out using an open kneader with the same composition as in Example 1, and the mixture was kneaded with a calender roll to a thickness of 0.8 mm.
Was formed. A glass cloth having a thickness of 0.2 mm was adhered to the resin layer as a constraining layer, and release paper was adhered to one side. Peel off the release paper, stick it on a rectangular dull steel plate with a thickness of 0.8 mm, heat at 180 ° C for 20 minutes,
The resin layer was foamed and thermoset, and was brought into close contact with the steel sheet.

Example 3 30 parts by weight of a carboxy-modified liquid polybutadiene having a number average molecular weight of 2000 and 1,2 polybutadiene (JSR®)
B: 150 parts by weight of calcium carbonate, 50 parts by weight of an aliphatic petroleum resin, 10 parts by weight of a process oil, 20 parts by weight of sulfur, vulcanization with respect to a total of 100 parts by weight of 70 parts by weight of Nippon Synthetic Rubber Co., Ltd. 10 parts by weight of an accelerator and 10 parts by weight of a foaming agent were mixed and kneaded by an open kneader, and a resin layer having a thickness of 0.6 mm was formed by a calender roll. A glass cloth having a thickness of 0.2 mm was adhered to the resin layer as a constraining layer, and release paper was adhered to one side. The release paper was peeled off, affixed to a rectangular dull steel plate having a thickness of 0.8 mm, and heated at 180 ° C. for 20 minutes to foam and thermally cure the resin layer, and adhere to the steel plate.

Example 4 The procedure of Example 1 was repeated except that an aluminum foil having a thickness of 0.1 mm was adhered as a constraining layer.

Comparative Example A glass cloth having a thickness of 0.2 mm was adhered as a constraining layer to a thermosetting resin steel sheet reinforcing sheet (having a thickness of 1.6 mm) in which calcium carbonate was filled in an epoxy resin, and release paper was placed on one side. The release paper was then peeled off, and it was adhered to a rectangular dull steel plate having a thickness of 0.8 mm and heated at 180 ° C. for 20 minutes to thermally cure the epoxy resin layer and adhere to the steel plate. .

Each of the reinforcing sheets obtained above was tested according to the following test method. Table 1 shows the results. Test method (1) Weight measurement (unit: kg / m ² ): The weight per 1 m ^{2 of} each reinforcing sheet was measured. (2) Reinforcing force (unit: N) Using a tensile tester, place the steel sheet on the top and the steel sheet reinforcing sheet on the wedge-shaped sample table with a span of 100 mm, and start from the center of the span. Similarly, the wedge-shaped measuring device was lowered to be in contact with the steel plate. From this state, the measuring instrument was lowered at a speed of 1 mm / min, the load when the steel sheet sample to which the reinforcing sheet was attached was displaced by 1 mm was measured, and the load was multiplied by the gravitational acceleration to calculate the reinforcing force.

[0023]

[Table 1]

[0024]

Since the steel sheet reinforcing sheet according to the present invention is of a foaming and thermosetting type, it exhibits extremely excellent reinforcing properties as compared with conventional steel sheet reinforcing materials. Therefore, when used in automobiles, it is possible to contribute to weight reduction. Further, compared with the conventional product using expensive synthetic resin, the cost is significantly reduced, and the steel sheet reinforced sheet can be used mainly in the field where the use was difficult due to the cost. For example, it can also be used for household electrical appliances made of steel plates such as electric washing machines and electric refrigerators, and has a very wide application range.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification code FI B32B 25/10 B32B 25/10 F16F 15/02 F16F 15/02 Q (72) Inventor Hiroshi Suzuki 8-16 Toshima, Kita-ku, Tokyo No. 5 Japan Special Paint Co., Ltd. Development Center (72) Inventor Hirofumi Kondo 8-16-5 Teshima, Kita-ku, Tokyo Japan Special Paint Co., Ltd. Development Center (56) References JP-A-5-5044 (JP, A) JP-A-5-111973 (JP, A) JP-A-4-364937 (JP, A) JP-A-4-53837 (JP, A) JP-A-59-35232 (JP, A) ( 58) Field surveyed (Int. Cl. ⁷ , DB name) B32B 15/00-15/20

Claims (2)

(57) [Claims] 1. A steel sheet reinforcing sheet comprising a constraining layer and a foamed resin layer, wherein the foamed resin layer of the foamed resin layer comprises (a) a rubber having a number average molecular weight of 500 to 20,000,
(B) a mixture comprising 95 to 5% by weight of at least one selected from thermoplastic elastomers [(a)
+ (B)] 100 parts by weight, (c) inorganic filler 5
(D) 1 to 200 parts by weight of a tackifier (e) 0 to 200 parts by weight of a softener (f) 1 to 100 parts of a crosslinking agent
A reinforcing sheet for a steel sheet, comprising 1 to 100 parts by weight (g) of a foaming agent. 2. The reinforcing steel sheet according to claim 1, wherein the constraining layer is made of at least one material selected from the group consisting of glass cloth, carbon fiber, organic fiber nonwoven fabric, and metal foil. Sheet.