JPS6236982B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a treatment agent for water-dispersible glass fibers that can be very easily dispersed in a filament form in an aqueous medium. Traditionally, glass paper raw materials and reinforcing materials for inorganic hydraulic materials (gypsum, calcium silicate, cement, etc.) have been treated with water-soluble treatment agents and can be dispersed into filaments in an aqueous medium. Tupped strand products have been used in large quantities. To date, glass chopped strand products that have been used for such purposes are generally produced by pulling out a large number of glass filaments from a bushing at the bottom of the spinning furnace, and then using a coating device to coat the surface of the filaments with starch and polyvinyl. A treatment agent containing a water-soluble adhesive such as alcohol or gelatin as a main component is applied, and then a large number of glass filaments treated with the treatment agent are gathered into one bundle or several bundles using a guide or the like to form a glass strand. It is manufactured by rolling it up using a cake, and then cutting the rolled cake (hereinafter referred to as the cake) using a cutting machine. In this way, since there is a process of cutting the cake using a cutting machine, the cake as a raw material has a certain degree of convergence that does not impair the cutting workability during cutting and the quality of the cut glass chopped strand product. (meaning the state of bonding between filaments that is to be maintained in the form of a strand) is required. In other words, if the convergence of the strands that make up the cake is too weak, a large amount of glass fluff will occur during cutting, there will be many miscuts, and the quality of the cut glass chopped strand product will deteriorate.
A certain degree of convergence is required. Adhesive components that have conventionally been blended into water-dispersible glass fiber treatment agents include starch, gelatin, and the like. These adhesive components have a small effect of imparting cohesiveness, so in order to impart appropriate cohesiveness to the glass strand without deteriorating the cutting workability, it is necessary to apply a large amount of these adhesive components. There is also a method of adding polyvinyl alcohol to the processing agent.
The glass strand product manufactured in this manner has the problem that when added to an aqueous medium, it does not easily disperse into a filament state, and therefore requires a long time for complete dispersion. Furthermore, glass strand products treated with processing agents containing these adhesive components as main ingredients have problems with product lifespans, such as easy mold growth during storage and a limited storage period. In order to solve the above-mentioned problems of the conventional technology, the present inventors conducted intensive studies on the types of adhesive components of the processing agent, and as a result, they formulated a polymer that is a copolymer of acrylamide and vinyl acetate as the main component. By treating glass fiber with a treatment agent,
Highly focused glass strands with good cutting workability are obtained, no mold is generated, and the time for complete dispersion into a filament state (hereinafter referred to as defibration time) when added to an aqueous medium is extremely short. The inventors have discovered that the manufacturing workability and quality of glass paper, glass fiber-reinforced hydraulic nonpolar products, etc. can be improved, and have arrived at the present invention. Particularly desirable as the acrylamide/vinyl acetate copolymer which is the main component of the treatment agent of the present invention is a polymer having a polymerization degree of 200 to 20,000, which is obtained by polymerizing acrylamide and vinyl acetate at a molar ratio of acrylamide/vinyl acetate of 1/4 to 4/1. It is something. The present invention will be specifically explained below using Examples and Comparative Examples. Example 400 glass filaments were pulled out from a bushing having 400 holes, and the treatment agent formulations listed in Table 1 (treatment agent numbers 1, 2, 3, and 4) were applied to the glass filaments using an application device. The bundles were rolled up using a guide roller and dried at 125°C for 8 hours until the treatment agent adhesion rate was approx.
A 0.25% stock cake was prepared. These cakes were cut into 10 mm pieces using a cutting machine to prepare glass chopped strand samples. Ten grams of the glass chopped strand sample prepared in this manner was placed in a beaker containing 1000 grams of water, stirred with a stirrer, and the time required for complete defibration was measured. The results are shown in Table 1.

[Table] From Table 1, the defibration time of the glass chopped strands treated with the treatment agent numbers 1 and 2 of the examples, which are the treatment agent compositions of the present invention, is the same as that of the treatment agent numbers 3 and 2 of the comparative examples. It can be seen that the width is much shorter than that of the glass chopped strand treated in step 4.
Furthermore, the glass strands treated with treatment agents No. 1 and 2 of Examples had good convergence and extremely good cutting workability.

Claims (1)

[Scope of Claims] 1. A water-dispersible glass fiber treatment agent containing an acrylamide/vinyl acetate copolymer as a main component. 2. Claim 1, wherein the acrylamide/vinyl acetate copolymer has a degree of polymerization of 200 to 20,000, obtained by polymerizing acrylamide and vinyl acetate at a molar ratio of acrylamide/vinyl acetate of 1/4 to 4/1. Water-dispersible glass fiber treatment agent.