JPS60141657A - Cement composition with high cement keepability - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The purpose of the FJA of the present invention is to provide a cement composition capable of highly retaining cement during paper making. sec
/ Synthetic resin fibrous material made hydrophilic by Y and f seafood 6
．． By blending synthetic resin fibers made hydrophilic to 0(8)72 or higher into cement, the present invention aims to provide a composition that exhibits a cement retention rate equal to or higher than that of conventional methods during papermaking. .

Conventionally, in cement papermaking, asbestos has been mixed in to prevent cement from falling off the papermaking screen and to reinforce the paper product.

However, due to safety and health concerns, the use of asbestos has already been banned for some purposes in some countries, and other countries are also moving towards bans or restrictions, and there are no plans for the future. should not be used.

As a result of various studies aimed at solving the above-mentioned drawbacks of conventional products, the present inventor found that if a certain type of synthetic resin fibrous material is used instead of asbestos, it is possible to achieve an equivalent cement retention rate, and that the fiber It has been discovered that when bentonite or an additive mainly composed of bentonite is further used in combination with the bentonite, the cement retention rate can be dramatically improved, and the present invention has been achieved based on this finding.

That is, the present invention uses Portland cement, P Fisheries 0.
1-1. Or, ec/? Synthetic resin fibrous material and P seafood 6sec/? The present invention relates to a cement composition having a high cement retention rate and comprising the above synthetic resin fibrous material.

The Portland cement used in the present invention may be any commercially available product. It is a hydraulic compound that is usually obtained by mixing limestone, mainly composed of calcium carbonate, with clay, etc., and undergoing complex changes under ignition in a cylindrical horizontal rotary furnace called a kiln. -JISR5210C Portland Cement "Ordinary Portland cement" and "early strength Portland cement" specified in
Special cements such as silica cement, alumina cement,
Of course, magnesia cement and the like are also Portland cements of the present invention.

The synthetic resin fibrous material with a P water content of 0.1 to 1.0 and the synthetic resin fibrous material with a water content of 6/2 or more used in the present invention are themselves hydrophilic or hydrophobic synthetic resins. The obtained fibrous material is made of a hydrophobic resin or a resin with low hydrophilicity, and at least its surface is treated with the above f.
It has been made hydrophilic so that it can be grown in water.

The resins used are, for example, polyolefins, polyamides, polyesters, polyimides, polyacrylates, phenolic resins, polyvinylidene chloride, polysulfones, polyphenylene ethers, and others.

When polyolefins such as polyethylene, polypropylene, poly-4-methyl-1-pentene, etc. are used as resins, since the resins themselves are hydrophobic, a treatment to make the surface hydrophilic is required. Usually, the polyolefin is converted into a solution state of an organic solvent and this is injected into an aqueous medium containing polyvinyl alcohol, or the solution is poured into the polyvinyl alcohol-water system while vigorously stirring it to form an emulsion. Then, by cooling and solidifying, a surface-hydrophilized fibrous material is obtained. The fibrous material is usually used with an average length of 0.1 to 10-17.

Synthetic resin fibrous materials (<5ip) are processed as follows: 1. Measure with.

Other than setting the sheet basis weight to 50 (1/i), TAPPI
-r Measure the time required for evacuation in seconds according to the 221 standard.

The bentonite used in the present invention is a clay mainly composed of silica and alumina and i-montmorillonite, and may also contain proteinite, quartz feldspar, zeolite, etc. Moreover, unlike those for normal use, it may contain sand.

The blending amount of each component to create the composition of the present invention is selected as follows (based on the mold bone of the composition): 0(+) Portland cement usually 50 to 98% by weight, preferably 85 to 95% by weight , (11) surface hydrophilic synthetic resin fibrous material (hereinafter sometimes abbreviated as [51771; , 1] usually 0
．． 2-20% by weight, preferably 1-5% by weight.

The mutual ratio of both synthetic resin fibers is usually low P marine fiber/
High f marine fiber = 8/2 ~ 2/8, light and heavy t 8/2 ~
4/6゜01D Bentonite or an additive mainly composed of bentonite, usually 0.1 to 20% by weight, preferably 1 to 6% by weight.

Examples 1 to 6゜Ordinary Portland cement [Product name: Asano Cement (
(manufactured by Nippon Cement Co., Ltd.)], polyvinyl formal fiber (trade name: Vinylon FJ'/3103X3, average diameter 1d (
[manufactured by Kuraray Co., Ltd.]] 1.5 parts, surface hydrophilic polyethylene fiber average fiber length 1.6 questions, P water level 0, 5 sec/t
'] at each ratio listed in Table 1 and to this total amount; ~
1. Add 20 times the weight of water and mix until homogeneous.
Ruler Me
A sheet-made plate was obtained by forming the sheet into a plate shape of 250 m x 250 mm on the mesh of s.

After drying at normal pressure at 50 rpm for 10 hours or more, the cement retention rate of the paperboard was measured and the results shown in Table 1 were obtained.

From the table, it can be seen that by using the formulation of the present invention, a significantly high cement retention rate can be achieved simply by using the conventional 5IFp in combination with SFp from Suisan, which has a high P content.

Table 1

Claims (1)

[Claims] (1) Portland cement, r fisheries 0.1-8sec
A cement composition with high cement retention, characterized by comprising a synthetic resin fibrous material of /V and a synthetic resin fibrous material of P Suisan 6/1 or more.