JPS6129388B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a putty for repairing building materials for filling and repairing cracks, dents, etc. on the surface of wood, plywood, laminated wood, etc.

Traditionally, ordinary putty is made by kneading a water-soluble resin emulsion with wood flour, clay, extender pigments such as calcium carbonate, and calcium sulfate.
The dents were filled and repaired. An example of the composition of this putty is: extender pigment 70 parts acrylic resin 50% emulsion 20 parts water 10 parts additives 0.7 parts.

This putty repair uses a spatula or the like to manually squeeze into the repaired area, such as cracks and dents, so it is easy to squeeze into the repaired area, and it adheres well to the base material, so that after the repair, the putty can be squeezed into the repaired area. It is necessary to eliminate sinking and cracking of the putty.

However, with the conventional putty, after the putty is repaired, the moisture in the putty is absorbed into the base material and dissipated into the outside air, causing the putty to wear down and cause caving or cracking.

In order to prevent this loss, the conventional method was to mix in a large amount of wood powder or extender pigment, but since such extender pigments and wood powder reduce the wettability of the entire putty, it is difficult to squeeze it into the repaired area. This makes it difficult to remove with a spatula, resulting in a significant decrease in work efficiency. Furthermore, the adhesion between the putty and the base material deteriorated, and the putty often separated, resulting in an unavoidable drop in yield quality.

It is an object of the present invention to solve these problems of conventional repair putty. That is, the present invention comprises (a) a hydrophilic binder such as various water-soluble or emulsion-type resins or various latexes, (b) a lightweight aggregate exhibiting a hollow spherical shape of 250μ or less, and (c) 2 to 15% methyl cellulose. (hereinafter referred to as MC) using an aqueous solution, the weight ratio of (a):(b):(c) is 1:
By kneading in a ratio greater than 1/3:1 but not exceeding 1:2/3:1, it is intended to obtain a repair putty that has good workability and does not separate from the base material.

The configuration of the present invention will be explained below.

Hydrophilic Binder Various water-soluble or emulsion type resins that are hydrophilic binders are general resins including acrylic resins, urethane resins, polyester resins, and the like.

Latex is rubber, synthetic latex (NBR)
latex, CR latex, MBR latex)
etc.

These hydrophilic binders bring the lightweight aggregates into close contact with each other and between the lightweight aggregates and the base material.

Lightweight aggregates: Lightweight aggregates with a hollow spherical shape of 250μ or less include silica balloons, shirasu balloons, and perlite with a specific gravity of 0.15 to 0.2. Because the aggregate is lightweight, it has a larger capacity than extender pigments, which have a specific gravity of around 1, and can be mixed in a large amount.Since the aggregate is hollow spherical, the voids between the aggregates are minimized, and the moisture in the putty is reduced. Due to the volumetric shrinkage caused by absorption into the base material and dissipation into the outside air, since the volume of the lightweight aggregate is large, there is little overall loss, and there are very few cave-ins and cracks. Although it is possible to use lightweight aggregate of 250μ or more, it is not preferable because the amount of voids will increase, the volume loss after repair will be large, and the amount of depression will be large.

Furthermore, when the repaired area is squeezed with a spatula, the lightweight aggregate may be destroyed, leading to an increase in the amount of depression.

MC: The addition of MC improves the wettability of repair putty,
It makes it easier to squeeze into the repaired area and improves spatula handling, improving work efficiency.

In addition, the addition of MC improves water retention, and the moisture in the putty does not dissipate rapidly, that is, it dissipates gradually, resulting in a reduction in the amount of depression.

However, if the amount added is increased, the drying time becomes longer and workability is adversely reduced.

An example of the formulation is as follows.

A: MBR latex (50% solution) 100 parts B: 35 silica balloons C: 100 parts of 10% MC aqueous solution In the above example A:B:C=1:0.35:1 However, according to the experimental results The ratio of A:B:C is 1:1/3:1 or 1:2/3:1 Must.

If it is less than 1/3 of the hydrophilic binder MC of lightweight aggregate, the loss after repair will be large, and if it is more than 2/3, the viscosity and plasticity of the putty will be significantly reduced. Become.

The thus obtained repair putty of the present invention is made of wood,
It can be filled into repaired areas on the surface of plywood, laminated wood, etc. to prevent the putty from sinking, cracking, or coming off, and has the effect of improving the yield, quality, and productivity of construction boards.

〔Example〕

A repair putty is made from the above formulation example: MBR latex (50% aqueous solution) 100 parts, silica balloon 35 parts, 10% MC aqueous solution 100 parts, and the width of the plywood surface is 3 m/
A metal spatula was used to repair the crack with a length of 100 m/m and a depth of 0.9 m/m.

After the repair is dry, the putty depression in the repaired area is 0.05 ~
It was extremely small at 0.1 m/m, and no cracks were observed.

On the other hand, when using conventional putty, that is, wood flour or extender pigment added to a water resin emulsion and kneaded, the putty depression after repair drying was 0.4.
~0.6m/m, which was much larger than the putty of the present invention.

Claims (1)

[Scope of Claims] 1. A hydrophilic binder such as a water-soluble or emulsion type resin or a variety of latex; - A lightweight aggregate having a hollow spherical shape of 250μ or less; - A 2-15% methyl cellulose aqueous solution, respectively. The weight ratio is greater than 1:1/3:1 and is 1:2/3:
A putty for repairing building materials, characterized by being kneaded to an extent not exceeding 1.