JPS5930752A - Strain measuring composition - 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 present invention relates to a novel composition for strain measurement, particularly a water-temperature agent type composition for strain measurement prepared by adding an inorganic polymer paste, a curing agent, and a pigment.

Excessive stress and strain occurring in the materials of structures, ships, aircraft, vehicles, etc. often causes destruction, damage, etc., so it is necessary to detect them in advance. As a method for measuring this strain, it is usually recommended to use an electrical resistance strain meter or a coating forming composition that is less brittle.

The method of using a brittle coating composition takes advantage of the fact that when a strain of more than a certain level occurs in a material coated with this composition, cracks occur on the coated surface at that location. The magnitude, direction, and distribution of strain generated in the material can be calculated and estimated from the length, density, direction, shape, etc. of cracks generated on the surface of the coating material, so it can be used in a way that is different from measurement using an electrical resistance strain meter. Land for disaster relief is important.

Unlike ordinary coating materials, strain measurement compositions must be designed in such a way that they will crack even when the slightest strain occurs in the applied material. It is necessary that the coating and drying properties are such that there is no occurrence of burning cracks after drying.

Conventionally, a carbon disulfide solution of lime rosin, a modified version thereof, or a mortar composition has been used as the strain measurement composition. However, these materials are dangerous to handle and difficult to dry, and in terms of performance, cracks may form on the coating surface in the stress range of the material to be measured, such as the elastic range of steel. There were drawbacks such as difficulty. Therefore, the present inventor recently discovered that a composition based on resin acids and their metal salts has better physical properties than conventional ones, obtained a special RF (No. 824220), and put it into practical use. ing.

Resin acid compositions currently in common use improve strain sensitivity and drying suitability by controlling the ratio of resin acid and its salt and the metal content of the salt. However, this composition and other strain measurement compositions that had been used before then had drawbacks such as low strain sensitivity and significant influence of temperature and humidity qI during coating and drying or use. The 78 organic composition using resin acids etc. has a glass transition point Tg of 45 to 55.
℃, there was a drawback that the operating temperature was limited to 40℃ or less.

For structures used outdoors, the temperature of the material at the point of direct sunlight is 4.
Since the temperature easily rises to 0° C. or higher, there has been a desire to develop a composition that can be used under these conditions, which are often used practically.

Therefore, the inventor of the present invention has developed a product that can be used safely without causing any fire hazards or industrial accident problems due to solvents during painting.
In addition, there is little variation in strain sensitivity due to temperature and humidity during drying.
Compositions with higher Tg points and strain sensitivity were investigated. the result.

Based on a compound with an inorganic skeleton structure that has such a high Tg point, the internal stress is relaxed by the action of a solvent during the curing process, and the coating film formed after curing is modified so that it exhibits high brittleness. Basic research M20 states that if a reticular pulpit-forming composition containing ions is used, the drawbacks of conventional strain measurement compositions will be improved and strain measurement will be possible over a wider range of temperature and humidity. Any one of alkali silicate, metal colloidal limited product, and aluminum phosphate represented by xSiO An inorganic polymer base consisting of two or more types that can be stably mixed together, and one or two of acidic or latent acidic metal salts, basic inorganic salts, metal oxides, latent acidic organic compounds, and anionic organic compounds. The present invention provides a strain measurement composition containing a curing agent consisting of at least one type of curing agent.

To explain the present invention in more detail, the strain measurement composition of the present invention contains the above-mentioned inorganic polymer base, pigment, and curing agent, and is a water-solvent type prepared by mixing these with water. It is a composition.

In the present invention, the inorganic polymer base, that is, the base having an inorganic skeleton structure, is preferably a compound that forms a film having a glass transition point Tg of 40°C or higher after drying and hardening, and has such physical properties as In the present invention, alkali silicates, colloidal metal oxides, and aluminum phosphates having the structure of formula CII as described above are used as compounds. ◎ Conventionally, aqueous solutions of alkali silicates such as water glass have been used as hardeners and alkali silicates. Compositions with added pigments are adhesive paints,
It is well known that it is widely used as a protective agent, etc. Compositions prepared by these known methods are
Since the composition film has the ability to withstand various internal stresses or external stresses, cracks will not occur in the coating film due to small stresses within the elastic limit of the material to be measured (as is the purpose of the present invention). It could not be used as a strain measurement composition.

The physical properties of the film formed by alkali silicate are controlled by the molar ratio of the H1 type alkali ions and SiO□/M2o (hereinafter referred to as molar ratio), and the colloidal metal oxide is controlled by its average particle size and basicity. . In addition, the physical properties of aluminum glue/acid change depending on the acidity of the composition, so not all types can be used, and in order to increase strain sensitivity, film formation, hygroscopicity, and film strength are important. It is necessary to use an inorganic polymer base with a limited structure and specified additives.

To explain this in detail, the alkali silicates of M2O xsioz and yH2o are usually called lithium silicate, sodium silicate, potassium silicate, and ammonium silicate, and can be further subdivided based on molar ratio and hydration state. be. For example, in the case of sodium silicate, which is collectively called water glass, crystallinity,
There are various classifications according to the solid state, bath liquid state, etc., but the classification of bath liquid state and crystal form is not important (the selection of the type of alkali ion and molar ratio is important). The formed film has high adhesion, film-forming properties, and moisture resistance, and the molar ratio of alkali species is limited to Tg so that the film has a Tg point.
L is required. In the case of M=Li, NH4 in formula (I), if the molar ratio In the case of M=Na, a molar ratio x of 1 to 2 has the drawback that the formed film has a large hygroscopicity, so use a molar ratio of 2 to 4 or increase the apparent molar ratio. It is desirable to use it with

The former alkali silicate alone or a mixture of it and the latter alkali citric acid are often used. In the case of mixtures, the latter compound is used in an equal or greater amount than the former compound.

One way to increase the apparent molar ratio of alkali silicate is to replace a portion of the alkali ions with alkoxysilane groups,
Common methods include substitution with an alkyl 7-ran group or mixing with soluble silicic acid.

Colloidal metal oxides such as colloidal silica, colloidal alumina, and colloidal metal oxides can be used as one component of the inorganic polymer base used in the present invention. These colloidal compounds that partially have a hydrate or hydroxide structure can also be conveniently used. The stability of these compositions is largely determined by the particle size, so the particle size The smaller the diameter, the better, usually 200 mμ or less, preferably 150 mμ or less.

Furthermore, as other inorganic polymer bases in the present invention,
Aluminum phosphate salts are used. Metal phosphate salts that can form a film upon dehydration can be used for the purpose of the present invention, but aluminum paste/acid salts, particularly biphosphates, are often used. This contains a P-0-AI bond, but products in which part of AI is replaced with other metals and those in which part of phosphoric acid is replaced with boric acid can also be used. .

Generally, aluminum phosphates include aluminum orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, polyphosphoric acid,
Boron phosphate compounds are preferably used.

These inorganic polymer bases may be used alone, but it is also desirable to use a mixture of two or more of them that can be stably mixed.

Even if the inorganic polymer base itself is applied alone and dried, an inorganic film will be formed, but it is highly hygroscopic and cannot be used as it is. It is necessary to use inorganic or organic hardeners.

Various types of hardening agents are known for water glass, silica gel, and phosphorous aluminum, but a wide range of inorganic compounds are used (ZN, AI, etc.).

Although the method of using metals such as Ca-Si and Fe-3i is effective for curing itself, it is not unreasonable to use metals such as silicic acid-2- since the film becomes foamed and causes a large internal stress stage.
Calcium, silicofluoride, aluminum polyphosphate, zinc phosphate, titanium phosphate chelate, zirconium phosphate chelate, kaori/latent hostile metal salts such as montmorillonite, potassium aluminate, sodium aluminate,
Basic inorganic salts such as alkali stannate, alkali titanate, alkali zirconate, alkali polyphosphate and MgO1C
Compounds of outer iron such as metal oxides such as aO1ZnO-Fe2O3 and the like are mainly compounds of metals of groups 1 to 2 of the periodic table.

Examples of organic curing agents include formalin, glyoxal,
Latent sensory-sealing compounds such as acetaldehyde, formate ester, lactate ester, sodium polyacrylate, sodium lignin sulfonate.

Algin #! Anionic compounds such as salts and amine salts are used. However, the commonly used coal gas curing method has a slow curing speed and is difficult to apply to the purpose of the present invention. These Morganic or inorganic hardening agents may be used alone or in combination of two or more kinds. , Albumin, Zamlatex, and Ketone resin can also be used together.

The film formed from these inorganic polymer pastes and curing agents is colorless and transparent or white. The coefficient of thermal expansion of these films is larger than that of practical metal materials such as steel, so it is necessary to add pigments whose coefficient of thermal expansion is smaller than that of the coating film in order to alleviate thermal expansion distortion. There is. For the purposes of the present invention, it is desirable that the coefficient of thermal expansion is 5×10/”C or less.

For this purpose, water-insoluble metal compounds are used. As these metals, metals of groups 1 to 1 of the periodic table are mainly used, and oxides, hydroxides, carbonates of these metals, or composite compounds thereof are used.

Examples of metals include magnesium, calcium, zinc, aluminum, iron, silica, titanium, zirconium, tin, etc. Specific examples include magnesium chloride, calcium oxide,
Compounds such as calcium carbonate, aluminum fluoride, aluminum hydroxide, zinc oxide, titanium oxide, zirconium oxide, general pigments such as sericite, miculite, and talc, fluorescent pigments, radioactive pigments, and π-organic pigments. Pigments etc. can be used. There are no particular restrictions on the particle size of these pigments.

Method for dispersing pigments in an inorganic polymer base Cross-dispersion can be carried out using a conventional method such as a tonse mill, vibro mill, or attritor. These compositions, if desired,
It is also possible to use it by adding a coloring agent to adjust the color.The curing agent can be used at the same time as pigment dispersion, or it can be added in a separate process.
In addition, the prepared composition is applied to a thickness of about 0.01 to 1 coat by a conventional method such as a roller, spray, etc., and dried naturally or by heating with hot air, an infrared lamp, or other heater. and then subjected to measurement.

The proportion of each component is 15 to 90X% based on uncut polymer.
It is preferable that the amount of pigment is 1 to 50% by weight, and the amount of curing agent is 0.01 to 15% by weight.

For the film prepared in this way, for example, the paste is made of sodium silicate with a molar ratio of 1.0 and 20% of lithium silicate with a molar ratio of 6, and the water is made of aluminum oxide as a pigment.
The composition prepared using phosphorus zirconium as a hardening agent has a strain sensitivity of 500 microstrain even under conditions of 70°C and 80% RFI, and is good as a composition for measuring strain at high temperatures. .

Examples and comparative examples of the present invention are listed below. This example is not intended to limit the invention.

[Example-1] (Composition-1) 100 parts monoacetylaceto/titanium DP diluted with water to 44Be' (20°C)
8 parts of A chelate 30% water mW (DPA = 1 HF'o xy 1 methylmethane diphosphone) was added and stirred at room temperature, and a lithium polysilicate water bath solution (Si
O220%, L1202-1%, PH=11゜<
1.17) 25 parts were added and further stirred.

Magnesium oxide 15 with an average particle size of 1μ or less is added to this mixture.
% and kneaded for 5 hours in a magnetic Seel mill (composition-1).
) was obtained.

(Test method) 1) Material piece A stainless steel plate (305X x 2 SUS 27) whose surface has been sandpapered to a roughness of 10μRZ or more is coated with 0.
A frame was made by adhering a polyester film having a thickness of 13 fl, and (composition-1) was injected into the frame to a liquid film thickness of 0.15 mm to form a coating film on the material surface.

U) Drying This piece of material at 20℃±1℃, sumo wrestler 5R) I
After drying in a constant temperature and humidity chamber for 20 hours, drying at 120℃
It was heated and dried for 2 hours.

This is kept again in a constant temperature and humidity room for 2 hours. A test piece was prepared.

111] Measurement After heating this test piece at a valley temperature of 50°C and 100°C for 1 minute, stress was applied using a high-temperature strain sensitivity tester, and the cracks generated due to static aging were removed after 5 minutes had passed. was measured to determine the strain sensitivity.

Results As a result, (1) ℃ 500 μ Stray 7. 100 ℃ 70
The strain was 0μ, making it a good composition for measuring strain at high temperatures.

[Example-2, 3] (Composition-2) (Composition-1) was prepared in the same manner using alumina hydroxide (γ-boehmite) instead of magnesium oxide, and (Composition-2) ) was obtained.

(M4 composition-3) Prepared in the same manner as in (composition-2) using aluminum oxide instead of magnesium oxide, (composition-3)
I got it.

Results Compositions 2 and 3 were tested in the same manner as in Example 1, and the strain sensitivity was determined. The results are as follows, and they were good as compositions for measuring strain at high temperatures.

50"C100℃ Composition 2 600 800 (Microstrain) // 3 500 70
0 [Example-4] (Composition-4) Lithium polysilicate aqueous solution (SiO2 20%, L
1202-2%, PH=11.5. d≦:21.18
) 10 parts of colloidal silica was added to 90 parts and mixed uniformly, and 6 parts of DPA-zirconium chelate (O/L/Kachix ZB 30% water bath liquid manufactured by Matsumoto Seikai Co., Ltd.) was added thereto and further mixed uniformly.

After that, add talcum to the Takesumi cod? - Stirred with Lumil for 2 hours to obtain (composition-4).

(Composition-5) In (ffi composition-4), 10 parts of titanium oxide ground to 5 μm or less was used in place of talc, and a composition-5) was obtained in the same manner. .

Results A test was created in the same manner as in Example-1, and this was
The same test was conducted under high temperature and high humidity conditions of 0% RH and 100% RH. As a result, 100°C composition 4 650 800 C microstrain) #5 700 900
It exhibits good physical properties even under high temperature and high humidity.

[Example-5] (Composition-6) Hirosunki aluminum 40% aqueous solution (A12037.9
%, P2O532, 1%, PH=2.2. d251
．． 50) 100 parts of white carzene (silicic anhydride Si0□98%).

At OO, 1, particle size 10-15 mμ) 15 parts and bis(mo3noethyl acid phosphate) titanium chloride% aqueous solution (Matsumoto Siyaku Orgachix TOP, Ti 5.6%, P8
．． 1%) was added and mixed uniformly.

To this was added 10 parts of ZRO□ ground to 10μ or less and kneaded for 10 hours in a magnetic Dahl mill to obtain Composition-6.

A material piece was prepared by processing in the same manner as the result (Example-1), and 50
When the strain sensitivity was measured under the conditions of 40% RH at 100°C and 100°C, the strain sensitivity was 600 microstrain at 100°C and 800 microstrain at 100°C, which was good even under high temperature drying.

[Example-6] (Composition-7) Composition-7 was prepared in the same manner as in (Composition-1) except that 5 parts of ethyl lactate was added instead of acetylacetonate titanium DPA chelate.

As a result of testing in the same manner as the results (Example-1), 50°C, 10
The strain sensitivities at 0°C were 50 and 850 microstrains, respectively, which were good.

(Comparative Example-1) In (Composition-1), monoacetylacetotitanium-
A similar test was conducted using a composition containing no DPA chelate, but the composition absorbed moisture after being left at temperature for 5 hours and had poor strain sensitivity.

(Comparative Example-2) (Composition-1) was prepared by adding the same amount of sodium silicate without using the lithium polysilicate aqueous solution.

When a test piece was prepared in the same manner as in Example 1 and left in a constant temperature and humidity room, it became impossible to measure strain after 10 hours, resulting in poor sensitivity.

(Comparative Example-3) When (Composition-4) was prepared without adding DPA-zirconium chelate and a test piece was prepared and tested in the same manner as in (Example-4), moisture absorption was significantly distorted. Sensitivity was poor.

(Comparative example-4)

Claims (1)

[Claims] 1. Formula (I) M2O* xS i02''yH20 (M in the formula is LiJVJaJc or 7.: )X NH,
And X. y is a positive number) Any one of alkali silicate, metal colloidal oxide, and aluminum phosphate
An inorganic polymer paste consisting of a single species or two or more species stably mixed together, and a pigment consisting of a water-impossible metal oxide, substance, hydrated product or carbonate having a linear expansion coefficient of 5X10/°C or less,
(1) A strain measurement composition containing 1 m of any one of acidic or latent acidic metal salts, basic inorganic salts, metal oxides, latent a acidic compounds, and anionic M organic compounds alone or with a curing agent consisting of two or more types. . 2. The composition according to item 1, wherein the inorganic polymer-based metal colloidal oxide is colloidal silica, colloidal titania, colloidal zirconia, or colloidal alumina. 3. The inorganic polymer-based aluminum phosphate is an aluminum orthophosphoric acid, metaphosphoric acid, viroline number, polyphosphoric acid, or borophosphoric acid compound (σ)
Composition. 4. The inorganic polymer paste is of formula (I) where M=Li or Nf
(4+. x = 2 or more alkali silicate or carbon, and the formula (I
2.) The composition according to item 1, wherein M=Na or , X=2S4σ), etc. Q) A mixture of alkali silicate. 5. Pigments are magnesium, zinc, and aluminum. 2. The composition according to item 1, which is an oxide, hydroxide, carbonate, or a composite containing these of iron, silicon, titanium, zirconium, and tin.