JPS62192469A - Paint composition for iron pipe - Google Patents

Abstract

PURPOSE:To form a paint compsn. for iron pipes, which contains no carcinogen, is inexpensive and gives a coating film which is hardly discolored or cracked and has a similar performance to that of tar epoxy resin paints, by blending an epoxy resin with a hardener, gilsonite, a petroleum resin and a xylene resin as essential ingredients. CONSTITUTION:100pts.wt. in total of an epoxy resin having at least two epoxy groups per molecule and an epoxy equivalent of 150-1,000 and a hardener for the epoxy resin (I) is blended with 50-200pts.wt. gilsonite (II), 20-180pts.wt. petroleum resin (III) having a number-average MW of not higher than 2,000 and 10-70pts.wt. xylene resin (IV) as essential ingredients.

Description

[Detailed Description of the Invention] Industrial Application Fields The present invention relates to a coating composition for iron pipes that does not contain carcinogenic substances and is resistant to discoloration, cracks, etc. .

<Conventional technology> Conventionally, it has been used as a paint for iron pipes such as water iron pipes and gas iron pipes.
Tar epoxy resin paints, which have poor rust prevention, water resistance, and chemical resistance, and are inexpensive, have been widely used in this heel technology field.

<Problem to be solved by the invention> However, tar, that is, coal tar pitch Kr
It contains an i-polyhex component, which contains carcinogenic substances, and therefore, due to market demands, it has been desired to develop a paint to replace the tar-epoxy resin paint. However, since there was no immersive paint that was inexpensive and had the ability to form a film, we had no choice but to use a cool epoxy resin paint, even though we knew that it had the drawbacks mentioned above. That was the actual situation. If t'fC tar epoxy resin paint is exposed to strong ultraviolet light during the drying process of the paint film within a week, the color may change to brown A or cracks may occur. It is necessary to reapply an alkyd resin-based paint to maintain the properties.

In view of this current situation, the inventors of the present invention have conducted extensive research to develop a product that does not contain any carcinogenic substances, is inexpensive, resistant to discoloration or cracking, and is rust-proof.

In terms of water resistance, chemical resistance, etc., they have discovered a coating composition for iron pipes that provides a coating film equivalent to that of cool epoxy resin coatings, and have completed the present invention.

<Means for solving the problems> That is, the present invention provides (+1/per epoxy having at least one epoxy group in the molecule @/s O~1000 epoxy resin and epoxy curing agent 100 parts by weight (11
) Gilsonite 50-200 parts by weight (l
itl petroleum resin 20 with a number average molecular weight of 1k2000 or less
-/za0 parts by weight and (iVl xylene;j￥!i 70~7
0 parts by weight of a coating film-form 11ffl component, and if necessary, mineral fillers such as extender pigments, anti-rust pigments, and coloring pigments, various additives, etc. are dissolved in an appropriate organic solvent. This invention relates to a coating composition for iron pipes.

In the present invention, as the epoxy resin, epoxy resins conventionally used in tar epoxy resin paints can be used. Also, epoxy resin is about 750 to 100
A value of 0 is preferred. If the epoxy equivalent is less than about 150, the coating will remain sticky and have poor drying properties, and will have an epoxy equivalent of about 100.
If it exceeds 0, it will be difficult to dissolve in the solvent, and it will be necessary to use a large amount of solvent, which will lower the solid content of the paint.

That is, as a commercially available product, Epicoat t2
g, same g311. times g3A, same 10θ11 same 0X-2;
! (Product names manufactured by Shell Chemical Co., Ltd.), Araldite GY
-260 (product name manufactured by Ciba Geigy), DER,? ,7
0. Bisphenol-type epoxy toilet fat such as Dow Chemical Co., Ltd. 3311 and above 337c), Epiclon gO0 (trade name manufactured by Dainippon Ink Kagakujo Co., Ltd.): DEN da,
Phenol novolac type epoxy resins such as il, reig (trade names manufactured by Dow Chemical Company); Araldite CT
Polyglycol-type epoxy resins such as -50g (product name manufactured by Ciba Geigy); Ebiclone: l 00% Ester-type epoxy resins such as Da00 (product name manufactured by Dainippon Inchu Kagaku Kogyo Co., Ltd.), etc. are representative examples. It is mentioned as something like that.

As the epoxy curing agent, compounds that are commonly used as curing agents for epoxy resin Wct can be used. For example, aliphatic polyamine, modified aliphatic polyamine,
Examples include polyamide amine, aromatic polyamine, and modified aromatic polyamine. The mixing ratio of epoxy resin and epoxy curing agent is arbitrarily determined depending on the type of both.
Normally, if the value (active hydrogen equivalent of curing agent/epoxy resin equivalent value) is within the range of θS ~ 10, the original epoxy resin p
You can show off your fatty eggs.

Next, "Gilnonite" used in the present invention is a blackish-brown hydrocarbon compound produced from natural ore veins and has a high softening point and low sulfur content and ash content. A typical composition includes carbon content of 75 to 6% as main constituents, hydrogen content of 3 to 15%, hydrogen content of 15 to 5%, acid content of up to 2%, and ash content of up to 5%, and its properties. is the average molecular import/
30θ~/g00. Hardness (moh's 5cale)
Approximately ko, 5 degrees Celsius for penetration) approximately -1 ratio tlθ3~! , 06, softening point/30~iqo°C.

In the present invention, gilsonite is mainly used to improve rust prevention. In addition, due to its high softening point and hardness, it does not become sticky like petroleum-based asphalt, and it also contains almost no carcinogenic substances. The mixing ratio of Gilsonite is 10 parts of the epoxy resin and 10 parts of the epoxy curing agent.

Against the weight department! ;0-200 heavy blue part is suitable.

Note that if the proportion of Gilsonite exceeds the above range, the viscosity of the paint tends to increase.
It is necessary to use Vc, which is undesirable because it lowers the paint solids content and makes the paint more fragile. On the other hand, if the blending ratio is less than the above range, drying properties will deteriorate, which is not preferable.

Next, the petroleum resin used in the present invention is an aliphatic petroleum resin in which a conjugated diene of C5 fraction such as cyclopentadiene and 73-pentadiene is partially cyclopolymerized - a heavy oil by-product of petroleum naphtha decomposition. Among them, styrene conductors, resins made by hydrogenating C9 fractions such as indene, and alicyclic petroleum resins made by polymerizing dicyclopentadiene, and low molecular weights with a number average molecular weight of about 500 to 000. It is a polymer. It should be noted that if the molecular weight is higher than the above upper limit, the flexibility of the coating film will be reduced, which is not preferable.

In the present invention, by incorporating an appropriate amount of petroleum resin into the paint, the poor compatibility between the gilnonite and the epoxy resin can be overcome, and as a result, it becomes possible to form the composition into a paint. Furthermore, when a large amount of gilsonite is used in a paint, the viscosity tends to increase, but by blending the petroleum resin, the viscosity of the paint can be appropriately lowered and the drying properties of the paint film can be improved.

The appropriate blending ratio of the petroleum resin is 20 to 1 gO parts by weight per 100 parts by weight of the epoxy resin and epoxy curing agent. If the blending ratio of petroleum resin is too much than the above range, the coating film will have a disadvantage of poor flexibility (or brittleness).On the other hand, if the blending ratio is less than the above range, the above-mentioned effects will not be as good. This is similarly undesirable since it causes the phase to disappear.

Next, the xylene resin that is conveniently used in the present invention is mainly a reaction product of metagysylene and form "f", and has an average molecular weight of about 30θ to 600 and a reactive group equivalent of about igo to a.
oo, * elemental content fig ~ / 3 weight ratio, viscosity (50℃
) gθ to 60θcgs is suitable. When kneading is used, the compatibility with gilsonite, epoxy resin, and petroleum resin is improved.

In the present invention, the medium silane resin improves the flexibility of the coating film.
It improves impact resistance and flexibility, and in addition, because the terminal methylol group of the xylene resin and the epoxy curing agent have high reactivity, it also has the effect of increasing the hardness of the coating film.

The appropriate mixing ratio of the xylene resin is about 10 to 100 x # parts by weight per 100 parts by weight of the epoxy resin and epoxy curing agent. It should be noted that if the blending ratio of the xylene resin is too much than the above range, the drying properties of the coating film will be poor and tackiness will remain, which is not preferable. On the other hand, if the blending ratio is less than the above range, the coating film tends to lose its flexibility and become brittle, which is also not preferred.

The coating composition of the present invention contains the above-mentioned coating film-forming components as essential components. 7- Other coating film-forming components, if necessary, include rust-preventing pigments such as zinc phosphate and aluminum phosphate to increase coating hardness and anti-corrosion properties; extender pigments such as talc and calcium carbonate; carbon black It is desirable to mix 30 to 50% by weight of pigments such as coloring pigments such as, etc. in the solid content of the paint, and it is also desirable to mix small amounts of additives such as anti-sagging agents and leveling agents.

The coating composition of the present invention has a coating film forming composition of 11iS consisting of the above.
C minute IC, further mix an appropriate amount of an organic solvent such as toluene, xylene, methyl ethyl ketone, butanol, etc., preferably 1 g per 20 to 60 seconds using a Ford cup ÷ Hiroshi formula.
It is made of 4 pieces.

The coating composition of the present invention is a two-component coating, and contains the above-mentioned epoxy resin and xylene resin in the main component, and an epoxy curing agent in the curing agent component. The component may be blended into either the base agent or the curing agent component. However, it is mainly blended into the main ingredient.

In the present invention, the coating material can be produced by known methods such as kneading in a roll mill, pebble mill, ball mill, etc., but it is particularly preferable to use a closed ball mill because it can prevent volatilization of the solvent.

Incidentally, the method of painting the iron pipe can be carried out in substantially the same manner as the conventional tar epoxy resin paint. That is, after surface treatment, a dry film thickness of 03 or more, preferably /θθ ~ by means of airless spray, air spray, brush, etc.
Paint it to a thickness of about 200μ and let it dry naturally. Incidentally, depending on the case, the iron water pipe may be heated to 60 to 9[theta]C in advance, or it may be allowed to dry out immediately after the coral coating.

<Effects of the Invention> The coating composition for iron pipes of the present invention has anti-M property, water resistance, and chemical resistance comparable to that of cool epoxy resin coatings that have been widely used in the past, and is superior to tar epoxy resin coatings. There are no drawbacks such as the poor working environment during painting, no elution of carcinogenic substances from the paint film, and no discoloration or cracking of the paint film in the summer. Furthermore, the coating composition for iron pipes of the present invention does not need to be re-coated (repaired) before shipping.
Furthermore, even in winter, the handling time is within t hours, which is of limited practical value.

The present invention will now be explained in more detail with reference to Example IK.

In addition, in the examples, "part" and "壬" are expressed based on the amount of t.

Example / Bisphenol type epoxy m fat CR Epicoat φ100
/J (Product name manufactured by Shell Chemical Co., Ltd.); Evo Medium Toname 4? S
, NV100 section] 77 parts, Gilsonite / 10 parts, aliphatic petroleum resin ["Escolets 3/θko" (trade name manufactured by Esso Chemical Co., Ltd.); average molecular weight about 550, NV100%] 9
1A, 3 parts, xylene resin ["Nicanol LLLJ (trade name, manufactured by Mitsubishi Gas Chemical Co., Ltd.): average molecular weight 3tθ, reactive group equivalent λ 5, NV/θQ%"J2!; part, jlk ri,
330 parts, anti-sagging agent/'Am, Kijiroru, ll19
fM,,) 5 parts of Luol Hiroshi and 790 parts of methyl ethyl keto were kneaded in a bot mill to prepare a main ingredient.

In addition, polyamide resin solution (active hydrogen equivalent: 5o, NVA
A curing agent component was prepared by mixing 600 parts of j% l, 10 θ parts of inbutanol, and 300 parts of triol in a disper.

90 parts of the base component and 7 parts of the curing agent component thus obtained.
0 parts were mixed to prepare a paint.

Paint is applied to degreased and polished layered steel & (RIθ×/, IO×θzaka) to a dry film thickness of 200μ, and -0
℃ for one week.

Thickening properties and stability of the obtained paint: Semi-curing properties of the film, bending resistance, impact resistance, adhesion, discoloration, water resistance, salt water resistance rg
Various tests were conducted on mistability, soda resistance, sulfuric acid resistance, and cracking resistance, and the results were as shown in Table 1.

Implementation f! AJ2 Bisphenol-type Evocorrosion Resin CrDER66/J (product name manufactured by Dow Chemical Co.): Epoxy Evocorrosion S, NV1
00 僑] // 3 parts, Gilnonite 700 parts, aliphatic petroleum resin [[Quint // 3; 2! ; LJ (product name manufactured by Nippon Zeon Co., Ltd.); average molecular weight 1500, NV100] g
9 parts, xylene tree 111r dicanol LLLJ2j parts,
Merck 113 parts, calcium carbonate 90 parts, carbon black 7 parts, aluminum phosphate pigment 30 parts, anti-sagging agent 30a, anti-cissing agent/4'i ((, Kijiroll 250
1 part, 50 parts of doluol, and 0 part of methyl ethyl ketone were kneaded in a bot mill to prepare a main ingredient.

In addition, amine adduct solution (active hydrogen equivalent 336, NVj
jl 164 (7 parts, isobutyl/-100 parts, and 2 s3 parts of doluol) were mixed in a disper to prepare a curing agent component.

90 parts of the main agent component and 7 parts of the curing agent component obtained in this way
0 parts were mixed to prepare a paint.

Examples below: The coating was applied to a layered steel plate in the same manner as rFij, dried, and subjected to various hammer tests.

Example 3 Bisphenol type epoxy m fat (r Epicote ψg-g
” (Shell Chemical Society product name); Epoxy a! / 90,
NV100=In]lAO part, bisphenol type epoxy resin "Epicote≠10θ/J4LO part, Gilsonite/3θ part, aliphatic petroleum resin "Finton/52S
110 parts of LJ, xylene resin "dicanol LLLJ 5
1 part and 2 parts of Kijirole were mixed in a disper to prepare a base ingredient.

Also, amine adduct solution C active hydrogen equivalent f: r22/.

A curing agent component was prepared by mixing 5 parts of NV (0 excellent) and 760 parts of Kijiroll in a disper.

90 parts of the base component and 7 parts of the curing agent component thus obtained.
0 parts were mixed to prepare a paint.

Apply it to the layered steel plate in the same manner as in the following example, dry it,
One test was conducted for each.

Comparative Example/Example/The same procedure was used except that the paint was made from P:A, and the paint was applied to a mild steel plate and dried.
I conducted a test.

Comparative Example 2 In Example 1, except that the stone/lil resin was removed and the amount of gilnonite was increased by the same amount, the paint was prepared in the same manner, applied to a polished steel plate, dried, and 4 test pas were conducted for each.

Comparative Example 3 Gilnonite was used as the main ingredient in Example/23
A paint was prepared by mixing the base component IIAM and 70 parts of the curing agent component using the same base components except that the base component IIAM was changed to 0 part and the Kijirole was changed to 900 parts. Apply the following to the layered copper plate in the same manner,
It was dried and subjected to various tests.

In Comparative Example 2, 270 parts of petroleum resin was used as the main component;
Paint #4 was prepared by mixing 15 parts of the main component and 10 parts of the curing agent component using the same base component except that Kijirole was used in an amount of 2 parts and g parts. Thereafter, the cloth was placed on a soft porcelain plate, dried, and subjected to each mallet test in the same manner.

Ratio 4 (Esari S Practical 2) Gysilene resin is used as the main ingredient at 710
Using the same base ingredients except for the following parts, 9 g parts of the base ingredients and 1 o I 11 parts of the curing agent were mixed, and the paint was cleaved. Thereafter, the coating was applied to a layered copper plate in the same manner, dried, and various tests were conducted.

Comparative Example 6 260 parts of coal tar pitch, 5 parts of bisphenol-type epoxy resin "Ebikotna 100/J", 50 parts of Tarkuco
700 parts of calcium carbonate, 1 g of anti-sagging agent, 10 parts of doluol, methyl ethyl ketone qom and amine adduct solution (active hydrogen per unit *33b, N
VSS%) 1140 parts, imbutanol 7
(
The mixture was mixed at a ratio of 100% near 0), and 1 volume of conventional tar epoxy resin paint was added.

The following examples were applied to a layered steel plate and dried, and various tests were conducted.

Sho/) A test to determine whether the initial viscosity of the main ingredient at 20° C. is 90 U or less, and the viscosity increases to 00 KU or more after 1 month L: O: Does not thicken, ×: Thickens.

Note 2) Put the main ingredient into the itA:@ tube and leave it for one week.

○: Not separated, ×: Separated.

Note 3) Test based on JIS-5q00 (In■
φ) ○: Pass, X: Fail Note lI) Test based on JIS-, lθOK (30
0y% l/2 inch, 30 pieces) ○: Pass, ×: Fail Note 5) JIS-54! Test based on θθ (baseline test) Sho 6) After 9 days of painting, water was placed on the painted pattern, and with a clock to prevent evaporation, it was exposed to sunlight/weekly with aS dew (7
month) exam.

○: No discoloration, ×: Discoloration Note 7) Monthly immersion test of moss in water ○: No abnormality, × Niblister or rust occurrence Note g) Salt water spray 1000 hour test ○:! ! ! No abnormalities, × Niblister or rust occurrence Note q) 5% caustic soda water - θ day immersion test ○: No abnormality, × Niblister or rust occurrence Note 1 O) 5 Hydrogen sulfur water θ day immersion test ○: 's Normal None, × Nibblister or rust occurrence Note//) After painting, one week exposure test under sunlight (one month) O: No abnormality, ×: Crank occurrence Note) Test based on JIS-5170 <20
C) less than 0270 hours, more than X:/Q hours Curvature evident from Table 1 The coating composition of the present invention had excellent coating performance and was acceptable for use on iron pipes.

On the other hand, the coating film of Comparative Example/d, which does not contain xylene 9111 ¥1, had no flexibility and poor bending resistance and impact resistance.

On the other hand, in Comparative Example 5, in which the amount of xylene/"...! fat was excessive, weldability remained in Coating 11.

Furthermore, the stability of the Comparative Example 2Fi paint not containing petroleum resin was poor, and the coating film performance was also poor. On the contrary, the Comparative Example DaFi coating film containing excess petroleum resin lacked flexibility and had poor bending resistance and impact resistance.

In addition, in Comparative Example 3 with excess gilsonite, the paint thickened and the coating workability was poor.

In addition, conventional tar epoxy resin paints not only contain carcinogenic substances, but also caused discoloration and cracks in the paint film during exposure tests in the summer.

Claims (1)

Scope of Claims: (i) 100 parts by weight of an epoxy resin and epoxy curing agent having an epoxy equivalent of 150 to 1000 and having at least two or more epoxy groups in one molecule (ii) 50 to 200 parts by weight of gilsonite (iii) Petroleum resin with a number average molecular weight of 2000 or less 20~
A coating composition for iron pipes, comprising a coating film forming component consisting of 180 parts by weight (iv) of 10 to 70 parts by weight of a xylene resin.