JPS5925868A - Composition for deicing material - Google Patents

Abstract

PURPOSE:The titled composition, containing a specific organopolysiloxane and an alkali metallic compound in a specific proportion, capable of completely preventing the sticking of frozen water to the surface of a body, and effective for preventing the danger of the icing on ships or aircraft. CONSTITUTION:A composition prepared by incorporating (A) 70-99.8wt% organopolysiloxane expressed by formula I (R is monofunctional organic group bonded to the silicon atom through a carbon-silicon bond, preferably 1-6C lower alkyl or H; R' is H, 1-20C alkyl, acyl, aryl or oxime residue; n<4; m<4; n+m<4) with (b) 0.2-30wt% alkali metallic compound expressed by formula II{M is alkali metal selected from Li, Na and K; X is inorganic acid radical, e.g. F, Cl or NO3, etc., OH, organic acid radical, e.g. HCOO or a saturated monocarboxylic acid radical of formula III [(n is an integer 0-20); a is an integer 1-4]}. A lithium compound, e.g. lithium acetate is preferred for the component (B).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composition for anti-icing materials, and more specifically, the present invention relates to a composition for anti-icing materials, and more specifically, a composition containing an organopolysiloxane resin as a pace,
By coating the surface of an object with a material in which an alkali metal compound is uniformly dissolved or dispersed in the matrix,
Regarding a composition for an anti-icing material that can prevent water from strongly adhering to the surface of an object when it freezes due to the synergistic effect of the anti-icing effects of a silicone resin and an alkali metal compound. This is due to the formation of hydrogen bonds between water molecules at low temperatures and exhibits a very large cohesive force.

The theoretical cohesive failure strength is said to be io, oook/i, but in reality it has been measured to be 16 to 80 kg/cd. The icing phenomenon occurs when hydrogen bonds are formed between water and the surface of an object, and exhibit extremely strong adhesion. Damage caused by icing and freezing occurs everywhere in cold regions and during the winter. For example, there are many dangers such as the danger of ice accretion on ships and aircraft, the danger of vehicle inoperability and accidents due to frozen roads and railways, the cutting of power lines and the collapse of houses due to snow accumulation, and the malfunction of transmitters and receivers. Ice buildup on ships is the most dangerous, as ice buildup on the ship's hull raises the center of gravity, leading to capsizing accidents. Many lives are lost every year because of this. In addition, anti-freeze agents are sprayed to prevent roads from freezing, but in the United States, for example, the amount of anti-freeze used reaches 10 million tons per year, and the resulting damage from rusting vehicles and contamination of groundwater is estimated to be over $100 million. In addition, research and development of these materials is becoming more active in conjunction with the need for anti-icing materials for the development of oil fields in the North Sea, which has become more active in recent years due to the depletion of oil resources.

Conventionally, as one of the measures to prevent icing, attempts have been made to reduce the icing force by applying various coatings to the surface of objects. As the coating material, acrylic resin-based, rubber-based, fluororesin-based and silicone resin-based coating materials are known. Among these, various silicone-based organopolysiloxane resins are particularly widely used. For example, Soviet Patent No. 789080 discloses a two-layer silicone anti-icing coating. Also, US Patent No. 42712
No. 15 discloses an anti-icing coating using a tetraalkoxytitanium compound as an adhesion catalyst to a specific silicone resin having carboxyl functional groups.

Although it is possible to more or less reduce icing by coating the surface of an object with these coating compositions, it is not possible to completely prevent strong adhesion due to hydrogen bonding of ice, and further improvements are needed. is desired.

The inventor conducted basic research on the mechanism of icing and classified it into three factors: interface science, physical, and thermodynamic. As a result, silicone polymers have a higher icing property than any other polymer. However, it was confirmed that the adhesion of ice to any type of ice is quite strong, regardless of the type of polymer, and as a result of further intensive research, a prucari metal compound and a silicone resin, which have a hydrogen bond dissociation effect, were discovered. They discovered that icing can be completely prevented only by the synergistic effect of the combination with the above, and have completed the present invention.

Thus, according to the invention, (~ the following unit formula % formula % (wherein represents a monovalent organic group or hydrogen bonded to silicon through a carbon-silicon bond, Z is hydrogen, C1-C2
0 alkyl group, acyl group, aryl group, or oxime residue. In the above formula, n and m each have a value of 4 or less, and n0m is less than 4) An organopolysiloxane resin 70 to 99.
8% by weight and (b) the following formula (where M is an alkali metal selected from Ll, Na and K, X represents an inorganic acid group, a hydroxyl group or an organic acid group; and a
is an integer from 1 to 4).

The effects of the composition according to the present invention on preventing icing are due to the surface properties and physical properties of the organopolysiloxane resin (5), which is one of the constituents of the composition, and the alkali metal compound, which is the other constituent. (I3) as a combined effect with the thermodynamic action, and complete prevention of icing can be achieved.

In other words, organopolysiloxane resin has hydrocarbon chains arranged on its surface, so its surface energy is low, and it also has very few polar components that tend to form hydrogen bonds, so it can be used for various purposes as a material for forming water-repellent surfaces. It is well known that this is the case. In addition to this low surface energy, the ability of organopolysiloxane resins to reduce icing is largely due to their physical properties, especially their low-temperature properties. In other words, the rigidity of the organopolysiloxane resin is low, and its low glass transition temperature prevents its molecular motion from freezing even under conditions of extremely low temperatures, for example, minus 30°C. It is difficult to become a target for hydrogen bonding during .

As described above, the icing ability is influenced not only by the surface properties of the coating film but also by the viscoelasticity of the bulk at low temperatures, and therefore the icing ability also changes depending on the thickness of the coating. For example, at -25°C with a film thickness of 50 to 200 μm, the adhesive strength is 1.2 to 0.8 kg/cA, but it is 5 to 10 μm.
For a thin film of m, it increases to 1.0 to 2.4 kg/d. Therefore, when, for example, 8 PHR of an alkali metal compound is added to the organopolysiloxane resin, the ice adhesion force becomes 0 even in a thin film of 5 to 10 μm.

To explain this mechanism using a lithium compound among alkali metal compounds as an example, the ionic radius of L1■ is small (0,6A!'), and therefore the hydration energy is l
25 kgA f/Ion and large (in mini N
a is 94.6 kgcsJ f/Ion Teal)
. Five molecules of water are adsorbed around the Socite L1e ion, and ten molecules of water are further adsorbed on the outside, but these water molecules are too close to the lithium ion.
7- Therefore, hydrogen bonds are not formed because they are adsorbed with greater energy than hydrogen bonds. That is, the lithium compound trapped in the matrix of the organopolysiloxane resin does not freeze water molecules adsorbed on the surface of the coating material, so ice does not adhere to it. Although such an effect is also seen with Na* ion and Ni* ion, L1* ion is much more effective and suitable.

The organopolysiloxane resin used in the present invention can be dissolved and dispersed and/or dissolved in water and an organic solvent to form a liquid state. k in the above formula is a monovalent organic group bonded to silicon through a carbon-silicon bond or hydrogen.

Examples of the organic group include methyl, ethyl, propyl,
Alkyl groups such as hexyl; cycloalkyl groups such as cyclohexyl, cyclobutyl, cyclopentyl; phenyl, tolyl, xyl groups such as IL/, 8-butyl; benzyl, phenylethyl,
Examples include aralkyl groups such as methylbenzyl and naphthylbenzyl; alkenyl groups such as vinyl, allyl, and oleyl; cycloalkenyl groups such as cyclopentadienyl and 2-cyclobutenyl; and alkenylaryl groups such as vinylphenyl. Among them, lower alkyl groups having 1 to 6 carbon atoms are effective in preventing icing.

In addition to hydrogen, the terminator in the formula can also be hydrogen, such as methyl, ethyl, propyl, butyl, amyl, hexyl, octyl, etc.
Examples include a C1-C20 alkyl group, t-aryl group; CI such as acetyl, propionyl, butyryl; C8 acyl group; oxime residue; and the like.

The above-mentioned organopolysiloxane resin used in the present invention can be used without any restriction on molecular weight as long as it can be dispersed and/or dissolved in water and organic solvents as described above, but it can be used without any restriction on molecular weight. The number average molecular weight is about 300 to about 1.000.000, preferably about 1,000 to about 1.000.000.
The range is approximately 500.000. Preferably, the organopolysiloxane resin has a reactive group such as a hydroxyl group or an alkoxy group in its molecule. Examples of such organopolysiloxane resins include,
Z-6018, Z-6188, 5ylkyd 50, D
C-8087 (Dow Corning product), Kk
-216, KR-218, KSP-1 (Shin-Etsu Silicone ■ product), TSR-160, TSR-165 (Tokyo Shibaura Electric (empty product), 5E1821.5E1980.5E9
140.5RX2 l l, PRX3 Q 5, SH2
Examples include 87,5H9551RTV (Toshi Silicone Product).

The typical curing mechanism of organopolysiloxane resin is (
They are the condensation type shown in I) and the addition reaction type shown in (It).

1 OH0I-1 ROHI(OR 1111 R 1 SiO-8i-0- 1 OOR I R.R. RRI(l( 11- 1 R.R. 1 KR 1 xt 　　　　　　　　　1ζ 12- or In the primary reaction formula, k and Z are the same as described above.

The amount of organopolysiloxane resin in the composition is 99.9%.
When the content exceeds 8% or becomes less than 70% (parts by weight), the icing property increases significantly.

On the other hand, M in the alkali metal compound [F]) represented by the general formula MaX in the composition is an alkali metal selected from Ll, Na and K, with Ll being preferred. It is also an inorganic acid group, a hydroxyl group, or an organic acid group, and an inorganic acid group refers to the remaining portion after removing one or more hydrogen atoms that can be substituted with a metal from an inorganic acid molecule,
Fe, Cle, B10 and Iθ0') Jl, Una single jlX Child and HiNO3e, Co 32e, P 0
4' e.

HPO4””, SO2”’, H3O4θ, Mn0
4e, Cr2O7"θ9Sin4"', 5in3"
It can include atomic groups such as θ, BO3e, ■043e, and WO4'e.

Furthermore, the term "organic acid radical" refers to the remaining portion of a saturated or unsaturated monocarboxylic acid or polycarboxylic acid molecule after removing one or more hydrogen atoms that can be substituted with a metal, such as HC:000 and the general formula CHs (CH2)n
Saturated monocarboxylic acid group expressed by cOoθ (n: an integer of 0 to 20) i General formula: unsaturated acid group such as maleic acid, oleic acid, linoleic acid; sono and other tartaric acid groups eOOC-(CHOH)2-COOe
Citric acid group CHC00e 1' HO-C-COOe 0H2C00e Polyvalent carboxylic acid group; and the like.

Further, a is determined depending on the type of inorganic acid radical or organic acid radical, and is usually an integer of 1 to 4.

Therefore, the following can be exemplified as representative examples of the alkali metal compounds represented by the above formula.

LiF, LiC1, Liar, Lit, , NaF, Na
C1, NaBr.

Na1. , KF, KCI, KBr, KI, LiNO3,
NaNO3゜KNO3, Li2CO3, Na2CO3,
2NO3, Li3PO4゜ 15- Na3PO4, KPO4, Li2SO4, Na2so4
．． 2SO4; L iMnQ4. NaMn04,
KMno 4, L i 2 Cr 207.

Na2Cr2O7, 2C1'207. Li4SiO4
, Li2SiO3゜Na4SiO4, Na2SiO3,
4Si04. 2Si03゜LiBO2, NaBO2
, KBO2, Li3VO4, Na3VO4゜K3VO4
, Li2WO4, Na2wo4. 2WO4HHCO
OLi.

HCOONa, HCOOK, L 12 C20
4, Na2C204.

K2C2O4, CH3COOLi, CH3COONa,
CH3COOK.

C2H,COOLi, Li0OC-CH2-COOL
i. Lithium citrate, sodium citrate, potassium citrate, lithium tartrate, lithium trimellitate, lithium pyromellitate, etc.

Among these alkali metal compounds, chloride has the greatest anti-icing effect. However, when such strong acid salts are used, they have the property of causing rust on metal materials, so care must be taken when using them. Next, carbonates, silicates, and acetates have the greatest anti-icing effect, and these are preferred because they have a long-lasting anti-icing effect and do not cause much rust. be. Further, among these alkali metal compounds, lithium compounds are preferred because they have a greater anti-icing effect than other sodium compounds and potassium compounds.

These alkali metal compounds can be used alone or in combination of two or more, and their blending amount is 0.2 to 80% by weight, preferably 0.2 to 80% by weight.
The ratio is 5-10%. If the amount of the alkali metal compound is less than 0.2% by weight, the anti-icing effect will be significantly reduced,
On the other hand, if it exceeds 80% by weight, the physical properties of the coating film will deteriorate and it will not be able to withstand long-term use.

In producing the composition of the present invention, the organopolysiloxane resin and the alkali metal compound are mixed using a steel ball mill, a pebble mill, an attritor, etc., which are common dispersion methods.

When preparing the composition for use as a paint, a solvent is appropriately used. The solvent may be any solvent as long as it can dissolve the organopolysiloxane resin as the base resin, and for example, solvents commonly used in paints such as chain or cyclic hydrocarbons, ketones, esters, and alcohols can be used. Water is naturally used when the paint is a water dispersion system.

The composition can be applied as a top coat on an undercoat film, or it can also be applied directly to metals, plastics, glass, wood materials, and the like. The composition can also be used as a molded product by being laminated onto the surface of an object, and if necessary, pigments, extender pigments, or dyes can be added to the composition (total of ingredients). 12 per 100 parts by weight
It can be added in an amount of 0 parts by weight or less. Other surfactants and additives can also be added as appropriate.

In addition, the icing property test was carried out by placing a stainless steel coated plate 8 coated with the composition of the present invention and having a size of 100 x 100 An adhesive terminal 5 having a flat bottom made of stainless steel is placed on the coating film 4 so that the adhesive area is 81.17 d, and a thin layer 6 of 5 to 10 μm of water is sandwiched between the adhesive terminal and the coating film. The ice-paint interface is then left in a freezer at -20 to -80' (!) for 5 to 72 hours.Then, in the freezer, the adhesive terminal is pulled upward using an adhesive tester 7 manufactured by Elcometer, UK. Measure the interfacial breaking force at tube 9
It was measured and evaluated (unit: kg/~).

Hereinafter, the present invention will be explained in more detail with reference to Examples. Parts and % indicate parts by weight and coulometric % unless otherwise specified.

Example 1 100 parts of an addition-polymerized organopolysiloxane resin (trade name: Toshi Silicone 5E-1821, 40% non-volatile content) and 2 parts of lithium acetate were added to a Red Devil type paint conditioner along with alumina silicate beads having a diameter of 5 WIH. Dispersed for 80 minutes. Then, 5E-1821Ca was added as a curing agent to this.
A composition obtained by adding 10 parts of t (manufactured by Toshi Silicone Co., Ltd., platinum-based catalyst) was applied onto a special copper plate for icing tests using an applicator, and baked at 100°C for 5 minutes. The dry coating thickness at this time was 12 μm. The icing strength was measured when frozen at -29°C for 16 hours using the test method described above.

In addition, as a comparative example, a composition prepared in the same manner as in Example 1 was used except that lithium acetate was not used (Comparative Example 1-1), and barium sulfate was used instead of lithium acetate. A composition using a composition prepared in the same manner as in Example 1 (Comparative Example 1-2) and a 2#! The icing strength of the material crimped to a thickness of 1 (Comparative Example 1-8) was also measured under the same conditions. The results of these tests are shown below.

20 Example 2 100 parts of addition polymerization type organopolysiloxane resin (trade name: Toshi Silicone 5RX-211. Non-volatile content 40%, number average molecular weight about 800,000 or more) and 0.5 part of lithium chloride were added as in Example 1. Dispersed in a similar manner. Next, a composition obtained by adding 0.6 parts of platinum-based catalyst 5RX-212Cat (manufactured by Toshi Silicone Co., Ltd.) was applied to this material in the same manner as in Example 1, and heated at 150°C for 8 minutes to form a 20 μm thick film. A dried coating film was obtained. The icing strength when frozen at -25°C for 44 hours was measured using the test method described above.

As a comparative example, a composition prepared in the same manner as in Example 2 was used, except that lithium chloride was not used (Comparative Example 2 1)%. Ice was formed under the same conditions using the composition prepared in the same manner as in Example 1 (Comparative Example 2-2) and the one using Teflon resin crimped to a thickness of 2 mm (Comparative Example 2-8). The strength was measured. The results of these tests are shown below.

Example 3 100 parts of polycondensation type organopolysiloxane resin (trade name: Toshi Silicone 5E-9140. Non-volatile content 40%) and 4 parts of potassium carbonate were dispersed and coated in the same manner as in Example 1, and 48 Let dry for an hour. The dry coating film at this time was 7 μm.

The icing strength was measured when frozen at -20°C for 5 hours.

Comparative examples include one using a composition prepared in the same manner as in Example 8 except that potassium carbonate was not used (Comparative Example 8-1), and one using a composition prepared by pressing Teflon resin to a thickness of 2 mm (Comparative Example 8-1). The icing strength of Example 8-2) was also measured under the same conditions. The results of these tests are shown below.

Example 4 100 parts of condensation type organopolysiloxane resin (trade name: Toshi Silicone PRX-805. Non-volatile content 40%, number average molecular weight approximately 800,000) and 1.0 part of lithium citrate were mixed in the same manner as in Example 1. This was dispersed and painted according to the method and left at room temperature for 24 hours to obtain a dry coating film of 80 μm.
The icing strength was measured after freezing at C for 5 hours.

28- As a comparative example, a composition prepared in the same manner as in Example 1 except that lithium citrate was not used (Comparative Example 4-1) was used, and a Teflon resin was crimped to the thickness of two sweetfish. The icing strength of the sample (Comparative Example 4-2) was also measured under the same conditions. These test results are shown in g6 below.

Example 5 Polycondensation type organopolysiloxane resin (trade name: Toshi Silicone 5) (-287, nonvolatile content 40%).

100 parts (number average molecular weight approximately 17.000), 2.5 parts of lithium oxalate and 40 parts of titanium dioxide were dispersed and coated in the same manner as in Example 1, dried at 50°C for 5 hours,
A coating film of 5 μm was obtained. When this material was frozen at -26°C for 22 hours, the icing strength was measured and was kept constant for 24 hours.

In addition, as a comparative example, a composition using a composition prepared in the same manner as in Example 1 except that lithium oxalate was not used (Comparative Example 5-1) and a Teflon resin were used. rIII
(Comparative Example 5-2), the icing strength was measured under the same conditions. These test results are below.
Shown below.

Example 6 Polycondensation type organopolysiloxane aqueous coating material (
Product name: Toshi Silicone, 8E-1980 Non-volatile content 45
%) and 1.2 parts of sodium chloride were dispersed and coated in the same manner as in Example 1, and left at room temperature for 48 hours.
A coating film of 80 μm was obtained by drying at 50°C for 8 hours.The icing power was measured when this product was frozen at -20°C for 5 hours.

As a comparative example, a composition prepared in the same manner as in Example 1 except that sodium chloride was not used (
The icing strength was also measured under the same conditions for Comparative Example 6-1) and one in which Teflon resin was pressed to a thickness of 2u (Comparative Example 6-2). These test results are shown below. Example 7 Addition polymerization type organoborisiloxane resin (trade name Square Resilicone 5H9551RTV, non-volatile content 100%) 1
00 parts and 10 parts of lithium carbonate were dispersed in the same manner as in Example 1, and 1 platinum-based catalyst (same as in Example 1) was added.
The composition obtained by adding 0 parts and stirring was molded onto a substrate for adhesion testing so that it had a uniform plane thickness of 27 parts M. This product was dried at room temperature for 48 hours and then frozen at -29°C for 18 hours, and the icing power was measured.

In addition, as comparative examples, one was molded using a composition prepared in the same manner as in Example 1 except that lithium carbonate was not used (Comparative Example 7-1), and one was molded with Teflon resin to a thickness of 2 my. The icing strength of Comparative Example 7-2 was also measured under the same conditions. The results of these tests are shown below.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view of an apparatus for testing the icing properties of the composition for anti-icing materials of the present invention. 1... Copper plate, 2... Styrofoam container, 8... Stainless steel coated plate, 27- 4... Paint film, 5... Adhesive terminal, 6...
- Thin film of water, 7... Adhesion tester, 8... Support stand, 9... Measuring tube, lO... Coil string, 11... Rubber gasket. (and above) 28-

Claims (1)

[Claims] ■ (f) The following unit formula (in the formula, represents a monovalent organic group bonded to silicon through a carbon-silicon bond, or hydrogen, K is hydrogen, c1 to C2
0 alkyl group, acyl group, aryl group or oxime residue. n and m in the above formula each have a value of less than 4,
(n0m is less than 4) An organopolysiloxane resin represented by 70 to 99.
8% by weight and (b) the following formula (where M is an alkali metal selected from Li, Na and K, and X represents an inorganic acid group, a hydroxyl group or an organic acid group. Also, a
is an integer from 1 to 4). (2) The composition for anti-icing material according to claim 1, wherein the alkali metal compound is a lithium compound.