JPS589754B2 - Method for manufacturing honeycomb sandwich German structural material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a honeycomb sandwich structure.

In detail, when manufacturing honeycomb sandwich structural materials, foaming is used as an adhesive between the surface material and the core material, and has excellent adhesion, cohesive force, and flexibility, and hardens while expanding its volume at room temperature. An object of the present invention is to provide a honeycomb sandwich structure material in which the fillet forming area is increased by adhesion using a foamed epoxy resin composition or a foamed chloroprene polymer composition using methylhydrodiene polysiloxane as an agent.

Composite materials, which are assembled by sandwiching a single bee core between two surface plates and bonding them with adhesive, generally have high strength and rigidity relative to their weight, and are relatively inexpensive in terms of the materials used. The expensive surface material can be made thinner, and the core material, which occupies most of the volume, can be replaced with a slightly cheaper material, making it an economical material overall.
It has important uses as a structural material for furniture, etc.

This honeycomb sandwich structure material is also largely due to advances in adhesives and bonding technology, and this type of adhesive has good peel, shear bond strength and creep resistance.
By increasing the fillet forming ability (adhesive concentration at the right angle area where the cell wall and face plate meet) and increasing the adhesion area between the face plate and the honeycomb core material, not only adhesive strength but also compression of the core material itself is achieved. There is a need for increased strength and shear strength, as well as low assembly and curing costs and no skill required for application.

Traditionally, urea, resorcinol, and phenolic resin adhesives have been used when using porous surface materials such as wood and hardboard, and when using non-porous materials such as metal, glass, and FRP as adhesives. For materials requiring adhesive strength, elastomer-phenolic systems, thermoplastic resin-phenolic systems, modified epoxy resin systems, etc. are used.
Each has the following drawbacks.

That is, phenolic resin-based adhesives release volatile components such as water during high-temperature curing and curing, and elastomer-modified adhesives release solvents, water, etc.

Therefore, it is necessary to make a large number of pores in the cell walls for gas release, which reduces the strength of the core material itself.

Furthermore, since the initial adhesion strength is excellent, the position cannot be corrected after adhesion, so the adhesion work must be performed with maximum accuracy.

Furthermore, it is necessary to use a roll or flat press for compaction.

In this respect, epoxy adhesives do not produce volatile by-products, have extremely low shrinkage, have excellent wetting properties, and have good fillet-forming properties, so they can be said to be the most suitable adhesive among these various adhesives. .

However, even though it is an epoxy resin, the thickness of the adhesive applied to the surface material, the core material, or both, and the fillet forming part, have volumetric shrinkage that occurs during curing. Even if it were possible to form a honeycomb sandwich structure, there would be no volumetric expansion during curing, and a sufficiently reliable honeycomb sandwich structure would be obtained, with only a slight increase in fillet formation due to the liquid adhesive being applied, sagging, and capillarity. It's hard to get caught.

The object of the present invention is to sufficiently enlarge the adhesive part between the surface material and the core material, that is, the fillet forming part, which is the most important part in a honeycomb sanderch structure, without increasing the coating weight, and to create a highly reliable honeycomb sanderch structure. It's about getting a body.

A feature of the present invention is that a foamed epoxy resin composition or a foamed chloroprene polymer composition that expands in volume while foaming is used as an adhesive between the surface material and the core material, and the fillet forming portion is bonded with the adhesive. The thickness after curing is larger than the thickness at the time of application, and the fillet forming portion is also increased by the expanded volume, so that the surface material and the core material can be sufficiently bonded without increasing the amount of adhesive applied.

Therefore, it is possible to obtain a honeycomb sandwich structure that is more reliable than conventional structures.

Here, the surface materials used in the present invention include aluminum plates, iron plates, metal plates made of alloys thereof, glass, ceramic product plates such as asbestos cement plates, calcium silicate plates, wood, plywood, synthetic wood (foamed wood), etc. plastic), wood, etc.
These are commonly referred to as building materials, including synthetic resins such as melamine decorative boards, acrylic boards, rubber sheets, etc., and composite materials made by printing on their surfaces or laminating veneers, films, metal foils, etc., and the foamed epoxy It refers to something that has adhesive properties to a resin composition or a foamed chloroprene polymer composition, or something that has adhesive properties due to primer treatment or the like.

Further, the core material refers to a core material exhibiting a honeycomb shape such as aluminum foil, phenol resin-impregnated kraft paper, unimpregnated kraft paper, FRP, and roll core.

Next, the foamed epoxy resin composition used in the invention as an essential component is one that uses methylhydrodiene polysiloxane as a foaming agent, and is cured while being foamed and molded by heating at room temperature, normal pressure, or medium temperature. The principle behind this is that when methylhydrodiene polysiloxane comes into contact with amines, which are the curing agent components of epoxy resins or liquid chloroprene polymers, ammonia gas is generated at room temperature and acts as a blowing agent. This refers to foamed epoxy-amine compositions, foamed polysulfide-epoxy resin compositions, foamed epoxy-chloroprene polymer compositions, foamed chloroprene polymer compositions, etc. with an expansion ratio of 3 times or less.

Next, regarding the adhesive application method in the manufacturing method of the honeycomb core sandwich structure, as is known, an adhesive is applied to the adhesion surface of either the surface material or the core material, or both. It is determined by the shape of the core material, the required adhesive strength, the weight of the structure, etc.

In addition, the molding adhesive processing method for the structure includes adhesive molding on one side at a time or both sides at the same time, etc. The properties of the adhesive, curing conditions, surface material,
The properties, strength, and dimensional accuracy of the core material are determined by molding equipment such as a compactor and heating device.

The first effect of the present invention is that the fillet forming part, which is the most important part in the production of honeycomb sanderch structure materials, is sufficiently large without increasing the coating weight, and a honeycomb sanderch structure with high adhesion reliability can be obtained. That's true.

Second, by applying a large amount of the foamed epoxy resin composition or foamed chloroprene polymer composition to the back surface of the surface material, that is, the adhesive surface, a thick foam is formed, so the resulting honeycomb sanderch structure is heat-insulating. , the effect of sound insulation can also be added.

Thirdly, since the foamed epoxy resin composition or foamed chloroprene polymer composition does not have volatile components, the core material (
Since there is no need to open pores for gas venting in the cell walls, the strength of the core material does not decrease.

Further, there is no need for special clamping and no skill is required for application.

Fourthly, even if the adhesive is processed with some lifting in the part that contacts the surface material (fillet part) due to unevenness of the surface material or uneven pressure during pressing, in the case of conventional epoxy adhesives, Although the foamed epoxy resin composition or foamed chloroprene polymer composition cures in that state, the foamed epoxy resin composition or the foamed chloroprene polymer composition adhesively cures while expanding in volume, so it is more reliable because it has the possibility of filling and bonding even the floating fillet part. A high-quality honeycomb sandwich structure is obtained.

The reason why the expansion ratio is set to 3 times or less is that if the expansion ratio is higher than 3 times, the cohesive force and adhesive force of the adhesive will be poor, and a honeycomb structure with sufficiently satisfactory adhesive strength will not be obtained.

Next, the present invention will be explained by examples.

Example 1 The adhesive surface of a commercially available rolled steel plate with a thickness of 0.65 m/m was sanded and then degreased to obtain a surface material.

In addition, commercially available paper has a thickness of 0.18 m/m and a cell size of 25 m/m.
, unimpregnated kraft paper honeycomb with a height of 40 m/m was used as the core material.

Next, the adhesive for honeycomb sandwich structures used in the present invention, Aica Aibon EX-505 (foamed epoxy-polyamide resin composition, foaming ratio 3.0 times, trade name of Aica Kogyo Co., Ltd.) is applied to the adhesive surface of the surface material. 30 with roll coater
It was applied at a rate of 0 g/m3.

Next, the stretched honeycomb core material is sandwiched between the adhesive surfaces of the adhesive-coated surface material, a contact pressure of about 0.1 kg/cm2 is applied, and the foam molding adhesive is cured by leaving it at room temperature for 7 days, and the fillet forming part is bonded. The height of the surface and the linear adhesive strength (tensile strength) between the surface material and the honeycomb core material were measured.

The measured values are shown in Table-1.

Comparative Example 1 Using the same surface material and honeycomb core material as in Example 1, the same amount of conventional epoxy-polyamide adhesive (unfoamed type) was applied, and adhesive molding was performed in the same manner to bond the fillet forming part. The height of the surface and the linear adhesive strength between the surface material and the honeycomb core material were measured.

The measured values are shown in Table-1.

Example 2 Commercially available plywood with a thickness of 6 m/m and commercially available asbestos cement board with a thickness of 8 m/m were used as surface plates.

Further, a commercially available roll core material having a thickness of 0.24 m/m, a cell size of 14 m/m, and a height of 30 m/m of phenol resin-impregnated paper was used as the core material.

Next, AICA Aibon EX-506 (foamed epoxy chloroprene polymer composition, foaming ratio 2.5 times, trade name of Aica Kogyo Co., Ltd.) was applied to each surface as an adhesive between the surface material and roll core material used in the present invention. It was applied to the adhesive surface of the material at a rate of 500 g/m using a roll coater.

Next, the roll core material is sandwiched between the adhesive parts of the surface material and the thickness of the roll core material is approximately 0. 1kg
The foam molding adhesive was cured by applying a contact pressure of /cm2 for 2 hours in a constant temperature bath at 50°C, and the height of the adhesive surface of the fillet forming part and the linear adhesive strength between the surface material and the roll core material were measured.

The measured values are shown in Table-1. Comparative Example 2 Using the same surface material and roll core material as in Example 2, the same amount of conventional epoxy-chloroprene polymer adhesive (unfoamed type) was applied and adhesive molding was performed in the same manner to bond the fillet forming part. The height of the surface and the linear adhesive strength between the surface material and the roll core material were measured.

The measured values are shown in Table-1.

Claims (1)

[Claims] 1 When manufacturing honeycomb sand German structural materials,
A foamed epoxy resin composition containing methyl hydrodiene polysiloxane as a foaming agent to bond the surface material and the core material, which easily hardens while expanding its volume by foaming at room temperature, and has a foaming ratio of 3 times or less. Alternatively, a method for producing a honeycomb sandwich structure material, which comprises bonding using a foamed chloroprene polymer composition.