JPS6025458B2 - Urethane resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a urethane resin composition, and its purpose is to increase the bonding strength between aggregate and resin components, improve the brittleness of the cured product, and improve the retention of wood screws, etc. An object of the present invention is to provide a urethane resin composition that can improve strength.

It has long been known to improve strength by mixing inorganic fillers such as calcium carbonate, silica balloons, perlite powder, and glass fibers into urethane resins, but these methods all result in non-uniform urethane reactions. Therefore, the cured molded product was brittle and had a low holding power for wood screws.

The present invention aims to overcome the drawbacks of such a conventional system, and will be described in detail below.

The present invention involves pre-impregnating part or all of absorbent powder, granular, or fibrous aggregates such as wood flour or pulp with amines, other catalysts, reaction accelerators, etc., and then injecting this aggregate into polyol. This polyol is mixed with an isocyanate compound. Note that a foaming agent may be added as necessary. The composition (molding material) thus obtained is molded, for example, into a silicone rubber mold or by other methods, and a cured product is obtained by a urethane reaction between the polyol and the isocyanate compound. In particular, wood that has been foamed to a specific gravity of around 0.4 is called synthetic wood and has properties similar to natural wood. In the present invention, as mentioned above, since aggregates such as wood flour and pulses impregnated with catalysts such as amines are blended, the reaction product of the polyol and the isocyanate compound is produced in the wood powder by the action of the catalyst in the aggregates. , it will firmly adhere to aggregates such as pulp, and therefore the urethane resin composition will not become brittle as would be the case if the polyol and isoanate compound were reacted by adding the bone material and the catalyst separately. It is possible to improve the holding power for wood screws, etc. In other words, if the polyol and isocyanate compound are reacted by adding and mixing aggregate alone, aggregates such as thick flour and pulp will not be involved in the reaction and will be used only as a filler, and will not be used as a urethane resin. The cured product of the composition becomes brittle, but by using aggregates such as wood flour or pulp that have been pre-impregnated with a catalyst, the aggregates can be used as resin components rather than simply being blended as a filler. As a result, Honemura can be used as a reinforcing material to improve the brittleness of cured urethane resin compositions and improve the holding power of wood screws, etc. Therefore, there is an advantage that the brittleness caused by mixing aggregate, as in the case of a casing, is eliminated, and the retention force for wood screws is good, making it possible to drive nails. In addition, when foamed to a specific gravity of around 0.4 and using wood flour as an aggregate, the properties, appearance, etc. closely resemble natural wood, and in particular, the holding power of wood screws is further improved. The present invention will be specifically described below based on examples.

[Example] 70 parts of a polyol (NM-401 manufactured by Nippon Soda Co., Ltd.) prepared by impregnating 50 parts of wood flour with an average particle size of 1 leg with 1 part of a catalyst (DMEA, manufactured by Nippon Nyukazai Co., Ltd.) and a polyol (Takeda Pharmaceutical Co., Ltd.) 30 parts of IR-96) and a catalyst (DME)
A polyol component was prepared by adding 1 part of A (manufactured by Nippon Nyukazai Co., Ltd.), 2 parts of a foam stabilizer (S-70, manufactured by Nippon Kunika Ichi Co., Ltd.), and various proportions of water as a foaming agent.

First, the catalyst-impregnated wood flour was added to the polyol component, and 120 parts of an isocyanate compound (44V-20 manufactured by Sumitomo Bayer Urethane) was added thereto and mixed uniformly.
Foam molding was carried out under the conditions of a liquid temperature of 290°C, a mold temperature of 4°C, and a molding time of 30 minutes to obtain a board-shaped synthetic wood. For comparison, synthetic wood was obtained in the same manner except that wood flour was not used. The relationship between the degree of foaming, that is, the specific gravity, and the holding power of wood screws was measured for the obtained synthetic wood, and the results were as shown in Table 1. 1st
Table 2 also shows that only the size of the wood powder was varied and the holding force of the wood screw and the state of the wood powder mixed were measured when the specific gravity was 0.4.

Table 2 However, in Tables 1 and 2, ◎ indicates excellent, 0 indicates good, △ indicates fair, and × indicates poor.

Claims (1)

[Claims] 1. A urethane resin composition comprising an aggregate such as wood flour or pulp impregnated with a catalyst such as an amine, and a polyol and an isocyanate compound.