JPH0131770B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a heat-resistant, flame-retardant and non-brittle water glass-polyester resin composite with good workability. Although inorganic materials originally have advantages such as excellent heat resistance and nonflammability, they also have the disadvantage that they are brittle.
As seen in the specification of No. 4011195, an unsaturated polyester resin with a high acid value and water glass are mixed, the acid groups in this resin are reacted with the water glass, and then the resin is polymerized and cured to make it flame retardant. There are also examples of inorganic-organic composites being obtained.

However, in this method, an interaction occurs at the same time as the resin and water glass are mixed, resulting in a sudden increase in the viscosity of the system, which requires mixing, stirring, and molding within a short period of time. In addition, although water glass itself can be made to have a high molecular weight by the action of acid groups in the resin, it is not sufficiently cured.

However, as a result of intensive research by the present inventors in order to solve the above-mentioned problems in the conventional technology, only unsaturated polyester resins that satisfy specific conditions were found. It has been discovered that a heat-resistant, flame-retardant and non-brittle composite can be obtained only by a unique method of curing the water glass and polymerizing the resin, The present invention has now been completed.

That is, the present invention requires (1) the condition that the hydroxyl value of the unsaturated polyester resin solid content is 400 or less;
(2) The acid value and hydroxyl value of the polyester resin solid content are expressed by the formula The resin, which satisfies the relationship expressed by The present invention provides a method for producing a water glass-polyester resin composite with good workability.

Here, the liquid water glass mentioned above is
General formula R ₂ O·nSiO ₂ ...[] [However, R in the formula is an alkali metal such as lithium, sodium or potassium, or a quaternary ammonium group, and n is a rational number of 0.5 to 4. ] refers to water-soluble alkali metal silicates represented by or their equivalent substances,
Among them, the representative ones are already 1 to 4.
There are liquid types commercially available as water glass, and these commercially available types may be used, and there is no preclude the use of an aqueous dispersion of powdered water glass.

On the other hand, the above-mentioned unsaturated polyester resin is
As a typical example, an esterified polycondensate of an acid component including unsaturated polybasic acids or their acid anhydrides and an alcohol component including polyhydric alcohol is dissolved or dispersed in a polymerizable monomer. It refers to resin, but among these,
In view of the emulsion dispersion stability of the resin in the water glass and the curability of the resulting composite, the amount of terminal groups in the esterified polycondensate, that is, the solid content of the polyester resin, is restricted, and It is desirable that this terminal group is substantially a hydroxyl group, and for this reason, the method of the present invention requires the use of a specific unsaturated polyester resin that satisfies conditions (1) and (2) as described above. . If these conditions are not met, the emulsion dispersion stability of the resin in the water glass may be poor, or the resulting composite may be poorly cured, which is not preferable.

Here, typical examples of the polymerizable monomer used for dissolving or dispersing the resin include styrene, α-methylstyrene, chlorostyrene, vinyltoluene, (meth)acrylic acid, or an alkyl ester thereof. acrylonitrile, acrylamide, diacetone acrylamide, vinyl acetate, acetate amide, triallyl cyanurate, triallyl isocyanurate or diallyl phthalate, among others.
Styrene or methyl methacrylate are preferred.

The weight ratio of unsaturated polyester resin solid content/polymerizable monomer is usually 30/70 to 90/10, preferably 40/60 to 80/20. The amount of the unsaturated polyester resin composed of monomers is 1 to 250 parts by weight, preferably 1 to 130 parts by weight, based on 100 parts by weight of the water glass solid content.

As mentioned above, the method of the present invention involves emulsifying and dispersing an unsaturated polyester resin in liquid water glass,
Next, the water glass is cured and the polyester resin is polymerized. For emulsification and dispersion, a surfactant is added at a ratio of 0.1 to 10% by weight based on the solid content of the water glass. It is preferable to do so.

Known and commonly used surfactants include:
Any of these can be used, but partial esters of polyols with fatty acids, partial ethers of polyols with long-chain monoalcohols, ethers of polyethylene polyols with fatty acids, nonionic surfactants such as polyethylene oxide condensates or polyethylene oxide/polypropylene oxide cocondensates can be used. Typical examples include anionic surfactants such as fatty acid alkali salts or alkylbenzene sulfonates; silicone surfactants and fluorine-based surfactants.

Any means may be used to emulsify and disperse the polyester resin in the water glass, but one typical example is to dissolve a nonionic surfactant in the water glass. Afterwards, there is a method of emulsifying and dispersing the resin.

The emulsified dispersion thus obtained can be cured by mixing and stirring a water glass curing agent and a polymerization initiator with the dispersion, then injection molding it into the desired shape, and then leaving it as it is or heating it. achieved.

Typical hardening agents for water glass mentioned above include sodium silicate, sulfuric acid, glyoxal, ε-caprolactone, and aluminum phosphates, but it goes without saying that any known and commonly used hardening agent can be used. Particularly preferred are those that exhibit a slow gelling effect, such as powdered materials and organic materials.

The proportion of the curing agent to be used must be appropriately selected depending on the type of curing agent, but for example, when sodium silicate is used, it is 5 to 40 parts by weight per 100 parts by weight of the water glass.

As the above-mentioned polymerization initiator, any initiator that is generally used for emulsion polymerization or unsaturated polyester resin can be used.
Representative examples include water-soluble peroxides or persulfates such as hydrogen peroxide, potassium persulfate, or ammonium persulfate;
Organic peroxides such as butyl hydroperoxide, cumene hydroperoxide, benzoyl peroxide or methyl ethyl ketone peroxide; or azo compounds such as azobisisobutyronitrile; these can be used alone or in combination. The above can also be used together.

Furthermore, known and conventional reducing agents and/or metal ions such as iron ions or cobalt ions, or various promoters such as dimethylaniline or diethylaniline may be used in combination with the above polymerization initiator.

The amount of the polymerization initiator used is usually
The proportion is 0.05 to 5 parts by weight per 100 parts by weight of the unsaturated polyester resin.

The temperature during polymerization of the polyester resin is suitably in the range of 0 to 100°C, preferably 20 to 90°C.

When carrying out the method of the present invention, there is no particular restriction on the order of curing the water glass described above and polymerizing the unsaturated polyester resin. There is also a method in which an initiator is blended at the same time, and after the water glass has hardened, the unsaturated polyester resin is polymerized by heating, and the method can be selected as appropriate depending on the purpose.

Thus, for the water glass-polyester resin composites obtained by the method of the invention, fibrous reinforcements such as glass fibers, ceramic fibers or whiskers; fillers such as; or various pigments such as titene oxide or carbon black.

Materials that are reactive with water, such as Bortland cement, alumite cement, calcined gypsum, or calcium sulfoaluminate, may also be used to help remove free water.

The composite obtained by the method of the present invention has the features of heat resistance, flame retardancy, and non-brittleness, so it can be used for housing materials such as wall materials or floor materials, automobile parts, electrical parts, etc.

In addition, as a modification of the method of the present invention, for example, there is a method in which a blowing agent is contained in a dispersion obtained by emulsifying and dispersing an unsaturated polyester resin in water glass, and then curing and polymerization are carried out. Since a water glass-polyester resin composite foam can be made, it can also be applied to various insulation materials, sound absorbing materials, catalyst carriers, filters, etc.

Next, the present invention will be specifically explained with reference to Examples and Comparative Examples. In the following, all parts and percentages are based on weight unless otherwise specified.

Example 1 No. 3 water glass (Osaka Sodium Silicate Co., Ltd. product; solid content)
40%) and 100 copies of "Emulgen 950" (Kao Soap Co., Ltd.)
After adding and completely dissolving 3 parts of phthalic anhydride (Nonionic surfactant), 60 moles of phthalic anhydride and
The solid content obtained by esterification polycondensation of 40 mol of maleic anhydride and 110 mol of propylene glycol is 55%, the acid value of the solid content is 1.5, and
40 parts of an unsaturated polyester resin whose solid content had a hydroxyl value of 55 was gradually added with stirring to emulsify and disperse.

Furthermore, 10 parts of sodium silicate was added and stirred to this emulsified dispersion, and then 1 part of a 50% DOP dispersion of benzoyl peroxide was added, mixed and stirred, and poured into a mold of 30 cm x 30 cm x 3 mm. The viscosity gradually increased and it hardened after 1 hour. After further curing and drying at 105℃ for 2 hours, a 1/2 inch, 500g weight was dropped using a Dupont impact tester, and no change was observed even when dropped from a height of 250mm. It was not recognized.

Furthermore, when the thus obtained cured composite was exposed to the flame of a gas burner for 2 minutes, no black smoke or new flames were generated.

Example 2 A composite with a glass fiber content of 30% was obtained in the same manner as in Example 1, except that the emulsified dispersion was impregnated into a chopped glass fiber strand mat.

The bending strength and Izot impact strength of this composite were measured according to JIS K-6911, and the results were as follows.

Bending strength: 18.5Kg/mm ² Flexural modulus: 1600Kg/mm ² Izot impact strength: 60Kg/cm/cm ² In addition, this composite was exposed to the flame of a gas burner for 2 minutes, but no black smoke or new flames were generated. Ta.

Comparatively 1. When 10 parts of the same No. 3 water glass used in Example 1 was mixed with 10 parts of sodium silicate,
It cured in 1 hour at room temperature. 105 this thing
After drying for 2 hours at <RTIgt;°C,</RTI> cracks appeared in the Dupont impact test (1/2 inch, 500 g) when dropped from a height of 250 mm.

Comparative Example 2 The solid content was 75%, the acid value of the solid content was 20, and the hydroxyl value of the solid content was 45. The resin and polymerization initiator were added with stirring in the same manner as in Example 1, except that an unsaturated polyester resin was used, and the use of sodium silicate was completely omitted. As a result, the viscosity immediately increased. This made stirring difficult. This material was placed in a 30cm x 30cm x 3mm mold, smoothed with a spatula, left to stand for 1 hour, and heated to 105℃ for 2 hours.
Although the composite was heated for an extended period of time, it remained soft and sticky, and was insufficiently cured to the point where it dented when pressed with a finger.

Comparative Example 3 The same procedure as in Comparative Example 2 was repeated except that 10 parts of sodium silicate was added while stirring, but the viscosity increased so much that stirring was no longer possible.

An attempt was made to put this material into a mold, but it had already lost its fluidity, and in the end no molded product could be obtained.

Claims (1)

[Claims] 1. Using liquid water glass and an unsaturated polyester resin that satisfies the following conditions, the unsaturated polyester resin is first emulsified and dispersed in the water glass, and then the water glass is cured and , and polymerization of the polyester resin,
A method for producing a water glass-polyester resin composite. (1) The hydroxyl value of the solid content in the unsaturated polyester resin is 400 or less, and (2) The formula between the acid value and hydroxyl value of the solid content of the polyester resin, respectively. The relationship expressed by is established.