JPS5939385B2 - Glass fiber surface treatment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for surface treatment of glass fibers for imparting alkali resistance and the like to the glass fibers.

Recently, silicon oxide (Si) has been added to mortar, concrete, etc.
n2), calcium oxide (CaO), magnesium oxide (MgO), boron oxide (B203), sodium oxide (
Na20), potassium oxide (K2O), aluminum oxide (A12o:3), lithium oxide (L120').

It is widely practiced to improve the strength, such as bending strength and compressive strength, and impact resistance of cement molded products by mixing long glass fibers and short fibers mainly composed of .

The thinner the thickness of the glass fibers, the higher the tensile strength and other strengths, and correspondingly, the stronger the bending strength, etc., of the cement molded product can be obtained, so it is recommended to use thin glass fibers. Recommended.

By the way, glass fibers having the above composition have a pH of
Although it has acid resistance in a wide range of acidic ranges from pH 2 to 6, it does not have alkali resistance in an alkaline range from pH 9 to 12, and due to the alkaline components in cement, CaO, MgO, which constitutes glass fibers, Alkaline earth metal oxides such as Na2O, 20. Alkali metal oxides such as Li2O are Ca(OH)2. Mg(OH)2
．． NaOH.

The glass fibers are dissolved as KOH and LiOH, resulting in a disadvantage that the strength of the glass fibers, especially the tensile strength, deteriorates.

In particular, in the case of thin glass fibers with a large surface area, the surface area that comes into contact with the alkaline components of cement increases, resulting in significant deterioration.

Recently, as mentioned above, as a method of imparting alkali resistance to glass fibers that do not have alkali resistance, zirconium oxide (Zr02) is added to conventional glass fibers using SiO2, Ca.
O2Mg02B202. 5 for Na2O, Al2O3
A method has been proposed in which a weight of ~25% is mixed.

However, if the amount of ZrO2 mixed is less than 10% by weight, glass fibers with sufficient alkali resistance cannot be obtained.

On the other hand, when the amount of ZrO2 mixed in is 10 to 25% by weight, glass fibers with a certain level of alkali resistance can be obtained, but it is not only extremely difficult to dissolve the raw material mixture during glass fiber production, but also difficult to dissolve. Even if it is, the liquidus temperature of the molten glass increases, resulting in a significant deterioration in spinning efficiency, inability to form glass fibers efficiently, and increased equipment costs.

Therefore, when ZrO2 of 10 weight coefficient or more is mixed, in order to eliminate the above drawback, Na20 + L t20
Adding an oxide of alkali metal No. 3 as a flux, C
aO, MgO.

The melting point is lowered by adding alkaline earth metal oxides such as BaO or aluminum group substances such as B2O3, but when the former alkali metal oxides are added, Weathering occurs, alkaline components are eluted, and the strength of the glass fiber decreases accordingly.On the other hand, when the latter, such as alkaline earth metal oxides, are added, the acid resistance decreases significantly, making it impossible to put it into practical use. .

As a method to overcome the drawbacks of the above-mentioned conventional method, the present applicant has proposed patent application No. 54-4738 filed on April 18, 1978.
No. 6 states that ``Glass fiber without alkali resistance or 2
Glass fibers with low alkali resistance containing zirconium oxide of less than 5% by weight are mixed with zinc, lead or tin chlorides,
After surface treatment with an aqueous solution of sulfate or nitrate or a mixture thereof to form an alkali-resistant protective coating on the surface of the glass fiber, the surface is treated with a mixture of an aqueous solution of the salt and an emulsion of a resin to form a layer on the protective coating. We have proposed a method for surface treatment of glass fibers characterized by the formation of a salt-containing resin film.

According to this method, not only alkali resistance is imparted to the glass fibers, but also properties such as weathering resistance, acid resistance, flexibility, etc. are imparted to the glass fibers.

As a result of further extensive research, the present invention was developed by forming an alkali-resistant protective film as described above, then heat-treating it at a temperature higher than the melting point of the salt, and then forming a salt-containing resin film on the protective film. The inventors have discovered that alkali resistance and the like can be further improved by forming a polyurethane resin, and have thus arrived at the present invention.

That is, the present invention provides surface treatment of glass fibers with an aqueous solution of zinc, lead or tin chloride, or a mixture thereof.
An alkali-resistant protective film is formed on the glass fiber surface by heat treatment at a temperature higher than the melting point of the salt, and then the surface is treated with a mixture of an aqueous solution of the salt and a resin emulsion to form a salt-containing film on the protective film. This invention relates to a glass fiber surface treatment method characterized by forming a resin coating.

The present invention will be explained in detail below.

First, zinc chloride (ZnC12), lead chloride [lead chloride (I)
(PbCl), lead chloride (■) (PbC12), lead chloride low) (PbCJ'4) tin chloride [tin chloride (If) (SnC
12), tin chloride (1'v) (SnC14)], or a mixture thereof, preferably 10 to 30% by weight.
Adjust the amount from 0 to 30 parts by weight.

This aqueous solution was poured into 5 in. A11203. MgO,C
aO, Bad.

Glass long fibers and short fibers with no alkali resistance made of appropriate combinations of K2O, Li2O, Fe2O3, Tio2, etc., or glass long fibers and short fibers with low alkali resistance made by blending ZrO2 with 25% by weight or less into the above glass fibers (
After surface-treating the glass fiber (hereinafter abbreviated as glass fiber) using an appropriate method such as dipping, spraying, or coating, heat treatment is performed at a temperature higher than the melting point of salt to make the surface of the glass fiber resistant. Forms an alkaline protective film.

The temperature of this heat treatment is 362°C or higher for zinc chloride, 501°C or higher for lead chloride (n), 246°C or higher for chloride value (■), and the melting point for both lead (IV) chloride and tin chloride (■) is 0. °C or lower, and the boiling point is about 100°C, so the temperature is set at about 80 to 90°C, but from the viewpoint of producing metal oxides, 300 to 400°C is preferable.

Therefore, as the chlorides of lead and tin, it is preferable to use divalent salts.

The heat treatment time is 60 to 90 minutes.

If the temperature is too low, sufficient heat treatment cannot be performed and a protective film with excellent alkali resistance cannot be formed, while if the temperature is too high, problems such as deterioration of the glass fibers may occur.

The formation of the alkali-resistant protective film is thought to be due to the following reaction mechanism.

As an example, a case where a silicate glass fiber is surface-treated with a Z n CIj 2 aqueous solution will be described.

In the case of silicate glass, N is present in the 5i-O network structure.
a”, L i +, Ca2+.

Cations such as Mg'' and Ba2+ are bonded with a weak bonding force, but when a ZnC12 aqueous solution acts on this glass surface, cations such as Na10 form a highly reactive G)C4-
Combines easily and quickly with anion NaCl.

Lice, CaCl2. MgCl2, Ba (J'2, etc.) are eluted from the glass surface as salts, and Zn2
+ is replaced by a cation such as Na+, and ZnO is formed during heat treatment, resulting in an excellent alkali-resistant protective coating being formed on the surface of the glass fiber.

It is stable against alkalinity and weak acidity at room temperature.

Next, after washing with water and drying, 2 to 80 parts by weight, preferably 10 to 300 to 30 parts by weight, 2 to 98 parts by weight of the above various salts and styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer A mixture of 10 to 500 to 50 parts by weight of a resin such as a polyvinyl acetate resin, a polyvinylidene chloride resin, an ethylene-vinyl acetate copolymer resin, a styrene-butylene copolymer, a fluororesin, etc.
A salt-containing resin film having a thickness of 20 to 50 μm is formed on the protective film by applying 98 parts by weight by an appropriate method such as a dipping method, a spraying method, or a coating method.

In addition, the above mixture may optionally contain alkali-resistant reinforcing inorganic compounds such as zirconium oxide and zirconium tetrachloride; plasticizers such as dioctyl tuclate and dibutyl tuclate; inorganic fillers such as calcium carbonate and silica; titanium oxide, etc. Pigments; Solvents such as benzene, xylene, toluene;
Appropriate materials such as surfactants such as cationic surfactants and nonionic surfactants can be added.

The glass fibers surface-treated as described above are then dried to form a surface-treated glass fiber product.

As described above, according to the surface treatment method of the present invention, a protective film having excellent alkali resistance is formed on the glass fiber surface, and a salt-containing resin film is formed on this protective film.

Since the protective film is protected by a resin film containing salt and having improved strength, the glass fibers surface-treated by the method of the present invention not only have excellent alkali resistance but also good abrasion resistance. properties, dispersibility, weathering resistance,
It has properties such as water resistance, acid resistance, flexibility, and bondability.

Therefore, the glass fibers surface-treated by the method of the present invention are well dispersed in mortar, concrete or plastic, and molded articles having a homogeneous substance are formed.

In addition, because it has good alkali resistance and abrasion resistance, glass fiber can be blended into mortar, concrete, or plastic without being damaged, and therefore has high strength such as bending strength and compressive strength and high impact resistance. Cement moldings and plastic moldings are formed.

Furthermore, since it has good flexibility and bondability, a cement molded product that does not cause problems such as cracks can be formed.

Furthermore, the practical effect of forming a molded product with high strength with a small amount of fibers is also achieved.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples.

〔Example〕

(5) First, an acidic aqueous solution of 20% Z n C12 having a pH of 4 was prepared.

This acidic aqueous solution has the following composition S i02 53.6
0 weight ratio Ca0 20.56 u ”203 14.38 ttB203
8.42 〃 Mg0 1.92 ttBao
0.58 〃 K O, Li 0 0.36 tt2 Fe2o30.22 Glass fibers of 13 μm and 150 mm in length (tensile strength 15.32 g/400 glass fibers per glass fiber) having weight f% of 1.5 at room temperature After dipping for seconds, heat treatment was performed at 370°C for 45 minutes.

Next, after washing with water and drying, 50 parts by weight of an emulsion containing a nonionic surfactant and a styrene-methyl acrylate copolymer and 50 parts by weight of a 20% Z n C12 aqueous solution were added.
A mixture of parts by weight was applied and impregnated.

After that, it was dried at 120°C for 10 minutes.

The amount of salt-containing resin deposited is approximately 39% by weight, and the film thickness is 38μ.
It was m.

In order to examine the alkali resistance of the surface-treated glass fibers as described above, the surface-treated glass fibers were immersed in a cent extract with a pH of 12.9 held at 80°C for a predetermined period of time, then taken out and washed with water. Dry.

Next, after dissolving and removing the adhering resin film with a chloroform solution, the filaments were taken out and the tensile strength of each filament was measured, and the results are shown in the table below.

In addition, Comparative Examples 1 to 4 are shown for comparison.

Comparative Example 1: Untreated glass fibers were subjected to an alkali resistance test in the same manner as in the above example, and then treated with a 10% HCg aqueous solution.
It was washed with water and dried at 120°C for 10 minutes.

After that, the tensile strength was measured in the same manner as in the above example.

Comparative Example 2: Untreated glass fibers were immersed in a mixture of 98 y of methyl alcohol and 2 g of silane (KBM503, manufactured by Shin-Etsu Chemical Co., Ltd.), and 0.46 weight percent of silane was applied thereto, followed by drying at room temperature.

Next, an alkali resistance test was conducted in the same manner as in the above Example, and then washed in the same manner as in Comparative Example 1, and then the tensile strength was measured in the same manner as in the above Example.

Comparative Example 3: After silane treatment in the same manner as in Comparative Example 2, an emulsion of styrene-methyl acrylate copolymer was applied and impregnated to form a resin film with a thickness of 40 μm.

Next, after conducting an alkali resistance test in the same manner as in the above example, the sample was treated with a chloroform solution, and then the tensile strength was measured.

Comparative Example 4: Glass fibers mixed with zirconium oxide were subjected to an alkali resistance test in the same manner as in the above example, and then washed in the same manner as in the above comparative example 1. After that, the tensile strength was tested in the same manner as in the above example. It was measured.

The results obtained in Comparative Examples 1 to 4 above are also listed in the following table.

As is clear from the above table, the glass fibers treated by the method of the present invention (Example) are superior to the untreated glass fibers (Comparative Example 1) as well as the silane-treated glass fibers (Comparative Example 2). It has better alkali resistance than the glass fiber treated with silane and resin (Comparative Example 3).

The glass fiber treated by the method of the present invention (Example) has better alkali resistance than the glass fiber containing zirconium oxide (Comparative Example 4), which has relatively high alkali resistance.

(b) Next, 62 parts by weight of the glass fibers of the present invention surface-treated as described above and the glass fibers of Comparative Examples 1 to 4 were added to 100 parts by weight of Portland cement, 300 parts by weight of standard river sand, and 65 parts by weight of water, respectively. Mix 40X40XI
It was molded to a thickness of 60 mm and cured in water for 28 days to form a mortar molded product.

The mortar molded products formed by blending the glass fibers surface-treated by the method of the present invention had higher bending strength than the mortar molded products of Comparative Examples 1 to 4.

Claims (1)

[Claims] 1 After surface treating the glass fiber with an aqueous solution of zinc, lead or tin chloride or a mixture thereof, heat treatment is performed at a temperature higher than the melting point of the salt to form an alkali-resistant protective coating on the surface of the glass fiber, and A method for surface treatment of glass fibers, characterized in that the surface is treated with a mixture of the aqueous solution of the salt and the emulsion of the resin to form a salt-containing resin film on the protective film.