JPS59223762A - Composition - Google Patents

Abstract

PURPOSE:To provide a paint compsn. having improved pot life and excellent corrosionproof performance and giving a coating film which does not cause sagging, cracking, etc., by incorporating xonotlite and zinc dust. CONSTITUTION:Acicular xonotlite having the major axis of 0.5-5mu and the minor axis of 0.05-0.3mu is mixed with zinc dust in such a quantity that the quantity of xonotlite accounts for 0.02-2wt% of the combined quantity of xonotlite and zinc dust. A pigment such as red lead, fine silicic acid powder, talc or red iron oxide is added to the mixture. Further, lithium silicate, water, etc. are mixed with the mixture to obtain the desired paint compsn. Xonotlite is hydrated calcium silicate of the formula 6CaO.6SiO2.nH2O and any of natural and synthetic xonotlites may be used. The resulting paint compsn. is suitable for use as a heavy-duty corrosion-resistant paint.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a zinc powder composition for paints containing xonotlite and a coating composition containing xonotlite and zinc dust.

Alkaline inorganic zinc-rich paints have traditionally been used as heavy-duty anti-corrosion paints.

However, when used as heavy-duty corrosion protection, a thick coating of several hundred microns is required, which has the disadvantage of causing problems such as sagging of the paint film during painting and cracking of the paint film when drying. As a solution to this problem, attempts have been made to increase the viscosity of the paint by replacing some of the zinc dust with other pigments such as red lead to prevent the paint film from sagging and cracking, but the expected viscosity has not been achieved. In many cases, satisfactory performance cannot be obtained due to poor corrosion resistance or a significant decrease in anticorrosion ability.

As a result of various studies, the present inventors have found that by substituting a portion of the zinc powder with xonotlite, the above-mentioned drawbacks can be overcome and the bot life can be improved.

The present invention will be explained in detail below.

The first aspect of the present invention is a zinc powder composition for paints in which zinc dust azonotlite is sufficiently mixed in advance before being added to the paint. The second aspect of the present invention is a coating composition to which zinc dust and xonotlite are added during the production of the coating.

There is no difference in paint performance such as anti-corrosion performance whether they are mixed in advance or added at the time of paint production, and they may be selected as appropriate depending on the circumstances at the time.

used h ruso/) 7 ito n 6 CaO-65
io2. '&u,.

It is a silicate hydrate represented by the formula, and it can be either a natural product or a synthetic product, but since it is used as a component of coating PI, the shape is a problem, and the long axis is usually 0.5 to 5μ and the short axis is 0.05μ. ~0.3μ is preferred. It is not preferable to deviate from this condition because it is more likely to have an adverse effect on the coating film.

The mixing ratio of zinc dust and xonotlite is such that the weight of xonotlite contained in the total amount (weight) of zinc dust and xonotlite is 0.05 to 0.05, regardless of whether the composition is pre-mixed or added separately to the paint. A range of 2.0% by weight is preferred.

In addition, red lead has traditionally been added and used as appropriate depending on the purpose.
There is no +tljM even if pigments such as fine silicic acid, curcum, and red iron are added together.

Furthermore, when preparing a paint composition in which zinc powder and xonotlite are mixed in advance, zinc powder alone usually solidifies and becomes lumpy if stored for a long period of time, so there is a drawback that it cannot be stored for a long period of time. It also has the advantage that it is less likely to solidify and can be stored for a longer period of time than conventional methods.

Heavy-duty anti-corrosion paints that require thick coating are usually water-based paints that use silicic acid, sodium silicate, and the like.

This will be explained in detail below using examples.

Example 1 A sacrificial material was prepared by pre-mixing zinc powder, xonotlite, red lead, and particulate silicic acid in the ratios (parts by weight) shown in Tables 1 and 2.

@Table 1, Table 2 78 parts of the above samples (experiment numbers 1 to 13), 20 parts of lyticum silica LSS-45 (manufactured by Nissan Chemical Co., Ltd.), and 2 parts of water were mixed together and dispersed using a day-spring funnel. , of paint,
Viscosity and corrosion tests were conducted.

The results are shown in Table 3, Table i4, and Table 5.

Table 3/'1 This is the result of measurement with Ford Cup positive 4.

Table 4 Table 4 shows the results measured using a B-type viscometer (30-meter model).

T and F are thixotropic factors.

Table 5 Table 5 was conducted using 3% saline and is based on a silver-silver chloride electrode.

Example 2 The degree of agglomeration during storage, that is, the storage M
'Ii: A qualitative test was conducted.

The results are shown in Table 6.

This is the change over time when canned.

◎Good (smooth and same condition as when manufactured) Good (
Not smooth, but not agglomerated) △ Normal (a small amount of lumps can be seen, but it is soft) Patent applicant

Claims (1)

[Scope of Claims] 1. Zinc dust composition for coatings containing xonotlite 2. Zinc dust composition for coatings according to claim 1 containing 0.05 to 2.0% by weight of xonotlite 3. The shape of xonotlite is needle-like, and its long axis is 0.
．． Zinc dust composition 4 for coatings according to claim 1, which has a diameter of 5 to 5μ and a short axis of 0.05 to 0.3μ; Paint composition 5 containing xonotlite and zinc dust; The coating composition according to claim '4, wherein the amount of xonotlite is 0.05 to 2.0% based on the total amount (weight). The coating composition according to claim 4, which has a short axis of 0.5 to 5μ and a short axis of 0.05 to 0.3μ.