JPH08253613A - Synthetic resin foam - Google Patents

Abstract

PURPOSE: To obtain a synthetic resin foam useful for constructing, etc., excellent in heat resistance, uniform in constitution and effective for natural resource savings and environmental countermeasures as recycling products by adding a powdery cured product of a thermosetting resin to a synthetic resin foamed material. CONSTITUTION: This synthetic resin foam is prepared by blending (A) a synthetic resin foaming material composition with (B) a powdery cured product of a thermosetting resin and foaming the mixture. The component B is preferably spur runners, cull runners, mold defectives generated during the molding of phenolic or epoxy resin material to be molded, a crushed product of used products, or odds and ends of phenolic resin laminates or epoxy resin laminates, their defectives or a crushed product of their products and the main component of the component A is preferably the thermosetting resin such as a phenolic resin, an epoxy resin, a urethane resin, etc., especially the phenolic resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin foam containing, as a compounding agent, a powder of a thermosetting resin cured product such as a cured product of a phenol resin molding material.

[0002]

2. Description of the Related Art Conventionally, as synthetic resin foams, thermoplastic foams such as polystyrene foam, polyethylene foam, polypropylene foam and vinyl chloride foam and polyurethane foam, phenol resin foam, epoxy resin foam, urea resin foam and the like have been used. There are curable resin foams, etc., which have heat insulation, cushioning, cushioning,
Due to its excellent acoustic properties (sound absorption, sound insulation), buoyancy, etc., it is used for building, vehicles, heat insulation materials for ships, packaging materials, mattresses, car seats, cushioning materials for chairs, lifesaving devices for ships and floats. It is used in a wide range of fields, such as sound absorbing walls and sound insulation panels for construction, depending on the purpose and application.

These foams sometimes form a foam only with a resin, and may contain a filler. When a filler is included, it is usually added to improve the drawbacks of the foam when the resin alone is used. There are various fillers to be blended in the foam, depending on the purpose. For the purpose of improving heat resistance, inorganic fillers have been used in many cases. However, when a liquid foam material composition is used, the inorganic filler has a larger specific gravity than the resin used for the foam, and during the foaming operation, it tends to settle at the bottom due to the difference in the specific gravity, resulting in a homogeneous composition. There was a problem that it was difficult to obtain the foam.

[0004]

DISCLOSURE OF THE INVENTION The present inventor has found that the foamed structure can be homogenized by adding a powder of a thermosetting resin cured product to a synthetic resin foam material composition, and the present invention has been made. It has been completed.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a foam obtained by blending a thermosetting resin cured product powder in a synthetic resin foam material composition and expanding the composition.

As the thermosetting resin cured product, a sprue runner or a defective product produced when molding a molded product with a thermosetting resin molding material such as phenol resin, epoxy resin, polyurethane resin, or a used product, or It is preferable to use a scrap material or a defective product of a thermosetting resin laminated plate such as a phenol resin or an epoxy resin, or a used product because it effectively utilizes the resources that have been discarded until now. Foams are used for various purposes, but heat resistance, flame resistance, and smoke resistance for foams used recently for soundproofing and heat insulation of buildings, vehicles, automobiles, etc. in order to improve safety against fire. The demand for sex has become stronger. In response to this requirement, among the foamed products, phenolic resins have attracted attention because they are particularly good in all of the above properties.

The phenolic resin foam has the highest heat resistance among synthetic resin foams, but various studies have been conducted to further improve the heat resistance. As a method for producing a phenolic resin foam, a liquid resol resin is used, and an acidic curing agent, a foam stabilizer, and a volatile solvent are added thereto to foam, and hexamethylenetetramine, which is a curing agent for a solid novolac resin, is used. Also, there is a method in which a solid foaming agent that generates gas at the time of heating is added to make a fine powder, and this is heated and foamed.

In order to improve the heat resistance of the above-mentioned phenol resin foam, a method of adding an inorganic filler such as clay, talc, calcium carbonate, silica, alumina, etc. can be considered, but these inorganic substances are more preferable than phenol resin. It has a high specific gravity and separates at the time of foaming of the resin, and particularly in the case of a liquid resol resin, it settles and accumulates at the bottom, making it difficult to form a uniform composition, and it is difficult to obtain a good foam.

In the present invention, among the thermosetting resin cured product powders used as the compounding agent, the cured product obtained at the time of molding the phenol resin molding material and the cured product obtained from the laminated plate are the dense structure having a pressure. Therefore, the heat resistance is particularly high, and by adding this to the phenol resin foam, a foam having good heat resistance can be obtained. Since the cured resin powder has a specific gravity close to that of the foam resin, there is almost no uneven distribution at the time of foaming, and because it is evenly dispersed with the synthetic resin that is the base material, there is little variation in composition and characteristics. Becomes

[0010]

【Example】

[Example] 100 parts by weight of novolac type phenol resin,
Hexamethylenetetramine 15 parts by weight, Selmark A
(Sankyo Kasei Co., Ltd., component: DPT) 5 parts by weight were mixed with a heating kneader and then pulverized to obtain a resin powder A for foaming having 100 mesh or less. The sprue runner generated during the molding of the phenol resin molding material (phenol resin: clay mineral filler = 60: 40 parts by weight) was pulverized to obtain a phenol resin cured product powder P having 100 mesh or less. (Distribution) Foaming resin powder A: 100 parts by weight Cured product powder P: 20 parts by weight The above components are thoroughly mixed and put into a mold and heated at 180 ° C. for 10 minutes to obtain a foamed product having a specific gravity of 0.2. It was

Comparative Example 1 Only foaming resin powder A was placed in a mold and heated at 180 ° C. for 10 minutes to obtain a foam having a specific gravity of 0.2. [Comparative Example 2] (Combined) Foaming resin powder A: 100 parts by weight Silica powder (100 mesh or less): 20 parts by weight The above ingredients were thoroughly mixed and put into a mold and heated at 180 ° C for 10 minutes to give a specific gravity. A foam of 0.2 was obtained. [Comparative Example 3] A comparative test was carried out using a commercially available urethane foam (specific gravity: 0.2).

The following characteristics were measured for the foams obtained in the above Examples and Comparative Examples. The results are shown in the table below. ──────────────────────────────── Example Comparative Example 1 Comparative Example 2 Comparative Example 3 ──────── ─────────────────────── Organization uniformity Good Good Bad Good Flame resistance Good Fair Good Good Bad Smoke resistance Good Good Good Bad ───── ──────────────────────────

[0016]

As is apparent from the above, the synthetic resin foam of the present invention has better flame resistance than the conventional one and is uniform and good in structure. Further, the foam of the present invention utilizes a thermosetting resin cured product that is originally discarded,
As a recycled product, it is effective for resource conservation and environmental measures.

Claims (5)

[Claims] 1. A synthetic resin foam obtained by blending a thermosetting resin cured product powder in a synthetic resin foam material composition and foaming. 2. The cured thermosetting resin powder is a sprue runner, cull runner or defective molding product generated during molding of a phenol resin molding material or an epoxy resin molding material, or a crushed product of a used product. Item 1. A foam according to item 1. 3. The foam according to claim 1, wherein the thermosetting resin cured product powder is obtained by pulverizing a scrap material or a defective product of a phenol resin laminated plate or an epoxy resin laminated plate, or a used product. 4. The foam according to claim 1, wherein the matrix component of the foam material composition is a thermosetting resin such as phenol resin, epoxy resin or urethane resin. 5. The foam according to claim 4, wherein the matrix component of the foam material composition is a phenol resin.