JPS6212811B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aqueous molding material resin composition, and more particularly to a molding resin composition based on an aqueous resin.

Known molding resin compositions have almost no volatile components and have a resin composition of nearly 100%.
That is, thermosetting resins, which have been known for a long time, and thermoplastic resins, whose demand has increased in recent years, are the dual walls of molding resins, but neither of them contains water in their resin compositions.

For example, when talking about thermosetting resins, the main types are urea resin, phenolic resin, and melamine resin, but these are also called formaldehyde resins, and formalin is one of the main raw materials, and the synthesis reaction is completed. At this point, the moisture in the formalin is mixed and the resin content and volatile components (mainly water) are roughly equal to half, so in order to use this as a molding resin, the moisture is naturally separated and further removed by heating and decompression. After that, it is cooled, crushed and sieved. In this case, a large amount of energy is consumed to remove a large amount of water after the synthesis reaction is completed.
Furthermore, since the removed moisture and steam contain formaldehyde, when wastewater is treated, it must meet wastewater quality standards. Further, the formaldehyde contained in the steam must be incinerated again, which requires a large amount of energy to be consumed again. As described above, the process is long, including reaction, moisture removal, pulverization, and sieving, and there are also difficulties in processing the removed moisture, resulting in poor productivity.

On the other hand, the main types of thermoplastic resins include polyethylene, polypropylene, vinyl chloride, and ethylene vinyl acetate.
It is in the form of granules or pellets, and naturally contains no water. Therefore, there is no problem with productivity, but
During the molding process, the resin is heated to a temperature at least 50°C higher than the softening point and melted into a liquid, which consumes a large amount of energy, requires cooling, is easily flammable, and requires a special injection molding machine. Disadvantages include the need for large machinery (compared to the size of the item being molded).

In this way, conventional molding resin compositions are
Basically, it is molded and hardened in a state where it is heated and melted to give it fluidity, so it was an essential condition that it was free of volatile components. Although these resin compositions have good molding performance, when an overlay sheet is molded at the same time as in the production of decorative laminates, paper cracking occurs because the overlay sheet does not have plasticity.

According to the present invention, an aqueous molding resin composition is provided, breaking the conventional wisdom. Although it was well known that resin mixed with around 10% water is cheap and easy to handle, it has not yet been put to practical use in the production of molded products, and as in the present invention, α-olefin It was completely unexpected that this would become possible through the use of maleic anhydride copolymer resins.

The main components of the aqueous molding resin composition according to the present invention are an aqueous formaldehyde precondensation resin (A) and a thermoplastic emulsion (B). All of them are resins that contain water as a volatile component (including solid resins such as powders and granules that are soluble in water, and those that mix easily with water and become viscous liquids).
The first characteristics of the present invention are that it is inexpensive because it is a water-soluble resin, that the thermosetting resin has the property of rapidly curing with heat to become a hard solid, and that the thermoplastic resin emulsion has suitable fluidity and In addition to combining the good crack resistance properties of thermoplastic resins, the blending of α-olefin maleic anhydride copolymer resin further enhances the balanced effect and crosslinking effect between thermosetting resins and thermoplastic resins. It is used as a viscosity modifier, fluidity modifier, flame resistant agent, etc. for aqueous molding resin compositions, and is used as a filler to provide durability and moldability such as heat resistance, crack resistance, and toughness. For example, it is possible to mix a fairly wide range of agents.

The reason why water-based resins have not been considered as molding materials is because, as mentioned above, they contain a large amount of volatile component (water). In contrast, the forming resin compositions of the present invention contain, as a second feature, 5 to 40% by weight of water, preferably 10 to 25% by weight. Therefore, it is liquid or viscous liquid at room temperature and has good fluidity, which is fundamentally different from conventional molding materials and allows for effective use of moisture.

The aqueous molding resin composition of the present invention includes (A) 5 to 50 parts by weight of an aqueous formaldehyde initial condensation resin and (B) α-
This is a composition prepared by mixing 100 parts by weight of a vinyl acetate resin emulsion containing an olefin maleic anhydride copolymer resin and 10 to 150 parts by weight of filler (C) so that the water content is 5 to 40% by weight.

Aqueous formaldehyde initial condensation resin referred to here
(A) is an initial condensate of phenol formaldehyde resin, urea formaldehyde resin, melamine formaldehyde resin, resorcinol formaldehyde resin, tannin formaldehyde resin, lignin formaldehyde resin, acetone formaldehyde resin, etc., and has a nonvolatile content of 40 to 70% by weight.
Refers to a water-based resin in the form of an aqueous solution or dispersion. Naturally, copolymer resins of the above resins, resins blended after reaction, or powdered formaldehyde resins can be used as the aqueous formaldehyde initial condensation resin (A) in the present invention, as long as they are dissolved in water.

The emulsion (B) containing an α-olefin maleic anhydride copolymer resin means that the α-olefin maleic anhydride copolymer resin is added in a proportion of 0.5 to
It is either 20% by weight added in advance or 0.5 to 20% by weight blended into the emulsion after reaction, and contains 40 to 70% by weight of non-volatile matter. When producing vinyl acetate resin emulsion, even if acrylic resin, ethylene resin, etc. are copolymerized to some extent, as long as the main component is vinyl acetate resin emulsion, it can of course be used as emulsion (B) in the present invention. .

Inorganic fillers (C) include calcium carbonate, talc, kaolin, gypsum, asbestos, cement, etc.; organic fillers include wheat flour, casein, cornstarch, blood meal, soy protein, starch, wood flour, walnut flour, and coconut. Powder, glue, gelatin, etc. can be used.

Regarding the relationship between the composition and the effect of the composition of the present invention, technical elucidation and technical theory have not yet been established. However, the properties of the curable resin of the aqueous formaldehyde initial condensation resin, the properties of the thermoplastic resin of the vinyl acetate resin emulsion, and the thermosetting and thermoplastic properties of the α-olefin maleic anhydride copolymer resin contained therein It is suitable for use as a molding material for water-based resin compositions because it has a well-balanced intermediate property between water-based resin compositions, acts like a cross-linking agent, and has good flow due to the water content. It seems possible.

Next, the present invention will be specifically explained using examples. Parts and percentages are by weight.

Example 1 Urea resin (Oshika Resin 20105, non-volatile content 60
%) 10 parts and 85 parts of vinyl acetate resin emulsion were emulsion polymerized in a conventional manner, and then α-olefin maleic anhydride copolymer resin was heated and dissolved in an alkaline aqueous solution so that it contained 10%. 100 parts of an emulsion (non-volatile content 50%) obtained by adding 15 parts of α-olefin maleic anhydride copolymer resin solution (50% nonvolatile content), 50 parts of calcium carbonate as a filler, and 20 parts of wheat flour (weak grade 2 flour)
A viscous water-based molding resin composition was prepared by thoroughly mixing 30 parts of corn starch and 30 parts of cornstarch.

This resin composition has a length of 1800 mm, a width of 900 mm, and a thickness of
When poured into a 10mm container, it naturally flowed to every corner. This was plate pressed at a low pressure of about 0.5 kg/cm ² at a temperature of 60° C. for 10 minutes to harden it.
The obtained molded plate can be used as wall material.

Example 2 A vinyl acetate resin emulsion was polymerized with a 15% aqueous solution in which 50 parts of melamine, urea formaldehyde resin (Oshika Resin No. 213, nonvolatile content 50%), and α-olefin maleic anhydride copolymer resin (isoban) were dissolved in an alkali. A non-volatile component obtained by adding it to a polyvinyl alcohol solution used as a protective colloid and reacting it using the APS method.
100 parts of a 40% vinyl acetate resin emulsion (containing 1% of α-olefin maleic anhydride copolymer resin as a non-volatile content), 20 parts of cationic fiber as a filler, 50 parts of talc and 20 parts of wheat flour,
A viscous aqueous molding composition was prepared by thoroughly mixing the two.

When this composition is put into a mold having a complicated uneven pattern, it naturally flows into every corner of the uneven pattern.
Therefore, a molded resin with a clearly reproduced uneven pattern was produced by a simple heating and pressing operation at 80°C for 10 minutes at 2 kg/cm ² .

Example 3 30 parts of tannin formaldehyde resin (Oshika Resin Plaitan, nonvolatile content 60%), 100 parts of the vinyl acetate resin emulsion shown in Example 2, 50 parts of potato starch as a filler, 20 parts of wood flour, and calcium carbonate. 20 parts, as well as brown pigment as a coloring agent
A water-based molding resin composition was prepared by mixing 0.5 parts. This resin composition was applied at 300 g/m ² on a gypsum board, and a mold with a Kamakura-bori pattern coated with a mold release agent was layered, and heated at 100°C.
By heating and pressurizing at 5 kg/cm ² for 5 minutes, a composite material having a resin layer with a Kamakura-bori pattern on a gypsum board was manufactured.

Claims (1)

[Scope of Claims] 1 (A) 5 to 50 parts by weight of an aqueous formaldehyde initial condensation resin with a nonvolatile content of 40 to 70%, (B) a nonvolatile content of 40% by weight.
Vinyl acetate resin emulsion containing ~70% by weight of α-olefin maleic anhydride copolymer resin
Consisting of 100 parts by weight and (C) filler 50 to 180 parts by weight,
An aqueous molding resin composition characterized by containing 5 to 40% by weight of water. 2. The aqueous formaldehyde initial condensation resin (A) according to claim 1, wherein the aqueous formaldehyde initial condensation resin (A) is a pentamer or less water-soluble or water-dispersed liquid resin containing a methylol group, a methylene bond, or an ether bond. Resin composition for molding. 3. The aqueous molding composition according to claim 1 or 2, wherein the vinyl acetate resin emulsion (B) contains 0.5 to 20% by weight of the α-olefin maleic anhydride copolymer resin.