JP2001329129A - Vinyl chloride paste sol composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a vinyl chloride paste sol composition whose storage stability is improved without losing various properties such as adhesivity and strength. SOLUTION: This vinyl chloride paste sol composition is prepared by adding a material which is to be absorbed on potassium carbonate and/or a vinyl chloride paste resin, and consists of at least one kind selected from the group consisting of a 10-22C saturated fatty acid, its amine salt and an amine salt of an unsaturated fatty acid while a vinyl chloride paste sol which contains the potassium calcium and the vinyl chloride paste resin is kneaded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vinyl chloride paste sol composition containing calcium carbonate.
More specifically, in a vinyl chloride paste sol composition used for various parts such as under the floor and a body, particularly for automobiles, its adhesion, strength and good stability during storage without impairing various required physical properties such as strength. The present invention relates to a vinyl chloride paste sol composition.

[0002]

2. Description of the Related Art Conventionally, a vinyl chloride paste sol, for example, a vinyl chloride paste sol for automobiles, is generally provided with a paste resin, a plasticizer, a stabilizer, a coloring agent, an adhesion improver, a filler and the like as required. After mixing, kneading and defoaming, a method of coating the surface of a steel sheet with a spray gun or the like and melting and gelling by heating is widely used.

However, when a paste sol is actually used, it is usual that the paste sol is temporarily stocked in a storage tank after production, and then transferred to a coating site in sequence. In order to prevent sedimentation / separation, etc., low-speed stirring at 10 rpm or less is always performed. In the storage under low-speed stirring, it is originally desirable that the state of the paste sol such as viscosity does not change with time. However, when calcium carbonate having fine particles is used, it is preferable to use In this case, the state of the paste sol such as the generation of aggregates or the decrease in viscosity may be significantly changed as compared with that immediately after the production, which is a problem.

As a method of solving these phenomena, a method of stopping stirring during storage, a method of limiting a storage amount according to a use situation so as not to store for a long time, and the like are adopted. In the case of, in order to stop the agitation that is originally used to prevent the sedimentation of the paste sol composition, sedimentation may occur in long-term storage, and in the latter case, the usage conditions In addition, it is not always easy to control the amount of storage according to the situation, and there are problems such as a situation in which it is not possible to cope with a sudden change in the use situation, and the production has to be unavoidably stopped.

On the other hand, calcium carbonate used as a filler in the paste sol composition is roughly classified into two types in Japan, which are produced by the following methods. One type is heavy calcium carbonate obtained by pulverizing raw limestone by a wet method, a dry method or the like, and classifying the limestone by various methods to obtain a powder or slurry having a desired particle size distribution. The other one is to calcine raw limestone into calcium oxide called quicklime, hydrate this calcium oxide to produce a calcium hydroxide aqueous suspension called milk of lime, and pass a carbon dioxide-containing gas through the milk of lime. Light calcium carbonate or colloidal calcium carbonate obtained at least.

[0006] In recent years, the automobile industry has been keenly examining the purpose of reducing the weight of automobiles as one goal, and there has been a trend toward plasticizing each component used in automobiles. Methods for reducing the specific gravity of the paste sol or reducing the amount of application are also being studied as methods for reducing the weight.

[0007] By these movements, conventionally, calcium carbonate has a relatively large average particle diameter, for example, 2 to 2
A grade of 3 μm was used in a large amount as an extender, and a small amount of fine calcium carbonate was used for the purpose of increasing the paste sol viscosity. Investigations to increase the amount of fine calcium carbonate have been made. If a large amount of calcium carbonate with a large average particle size is used,
Unless the specific gravity of the paste sol increases and the amount of the paste sol is not increased, a sufficient function of protecting the substrate such as a steel plate cannot be obtained.

[0008] Heavy calcium carbonate is calcium carbonate that is classified and adjusted into various grades by mechanically pulverizing limestone and classifying the pulverized material as described above, and has the characteristic that it can be produced at relatively low cost. On the other hand, calcium carbonate, which has a broad particle size distribution and a fineness of a certain level or more, has the disadvantage that it cannot be produced by current pulverization and classification techniques. I have to say that it is not suitable for movement.

On the other hand, with respect to precipitated calcium carbonate obtained by passing carbon dioxide gas through milk of lime, those having various shapes and primary particle diameters can be produced by the recent development of production technology, and serve the above-mentioned purpose. Calcium carbonate having a fine particle size with sufficient physical properties has also been produced and is currently used in various formulations.

However, the precipitated calcium carbonate forms calcium carbonate particles, and after the completion of carbonation, a small amount of an alkali component mainly composed of calcium hydroxide remains between the calcium carbonate particles. When the calcium carbonate is used as a filler in a vinyl chloride paste sol, due to the remaining alkali, the calcium carbonate is chemically bonded to the paste resin during storage under low-speed stirring to form a paste resin having calcium carbonate particles as a core. Aggregation occurs,
The occurrence of coarse aggregates or the excessive amount of plasticizer in the paste sol system causes a decrease in viscosity.

As a means for solving this phenomenon, it is conceivable to carry out dealkalization by pH control, or to completely coat the particle surface with a surface treating agent so that the alkali is not exposed from the calcium carbonate surface. However, in the former case, in order to remove alkali by pH control, although equipment and energy are required for a liquid circulation process such as stirring for a long time after completion of carbonation, complete alkali removal is required. Undesirable, and the eluted alkali content becomes calcium carbonate and precipitates on the existing calcium carbonate to increase the particle size, thereby sufficiently exhibiting the expected function when blended into the vinyl chloride paste sol. Has not been reached.

In the latter case, most of the surface treatment agents for calcium carbonate conventionally used in vinyl chloride paste sols are sodium or potassium salts of fatty acids called fatty acid soaps. Requires a large amount of treating agents as compared to conventional treatments. Furthermore, these surface treating agents are eluted between the steel sheet and the paste sol during gelation by heating after coating on the steel sheet, which causes a decrease in adhesion.

[0013]

As described above, the following two physical properties are required of calcium carbonate as a filler when a vinyl chloride paste sol used for automobiles is improved to be suitable for weight reduction. In addition, in using fine calcium carbonate, storage stability under low-speed stirring is added. (1) A paste sol having high viscosity can be obtained with a small amount of mixture in order to reduce the specific gravity of the paste sol. (2) A material having high functionality capable of exhibiting physical properties equivalent to those of conventional thick film coating in order to reduce the amount of paste sol applied.

As described above, at present, fine calcium carbonate capable of satisfying both of them has not yet appeared.

[0015]

DISCLOSURE OF THE INVENTION In view of the above-mentioned circumstances, the present inventors have satisfied the physical properties required particularly for a vinyl chloride paste sol for automobiles and have a good storage stability under low-speed stirring. As a result of intensive studies on the relationship between the sol composition and the fine calcium carbonate, a specific substance was added during kneading of a compound containing calcium carbonate, or a specific substance was added during kneading, and calcium carbonate surface-treated with a specific substance was added. Have been found to be able to satisfy all of the above requirements, and have completed the present invention.

That is, the present invention comprises at least one selected from the group consisting of saturated fatty acids having 10 to 22 carbon atoms, amine salts thereof and amine salts of unsaturated fatty acids.
A polyvinyl chloride paste sol composition obtained by adding an adsorbing substance to calcium carbonate and / or vinyl chloride paste resin at the time of kneading a vinyl chloride paste sol containing the calcium carbonate and the vinyl chloride paste resin. .

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, as a saturated fatty acid having 10 to 22 carbon atoms or an amine salt thereof having 10 to 22 carbon atoms, which is used as an adsorbent to calcium carbonate and / or vinyl chloride paste resin, specifically, for example, Capric acid (C10), myristic acid (C14), palmitic acid (C16), stearic acid (C18), behenic acid (C2
Examples of the saturated fatty acids or amine salts thereof such as 2) and amine salts of unsaturated fatty acids include lindelic acid (C
12 '), zomaric acid (C16'), oleic acid (C
18 ′) amine salts and the like;
Used in combination of more than one species.

These substances are preferably added in an amount of from 0.05 to 5 parts by weight, more preferably from 0.3 to 3 parts by weight, during kneading the vinyl chloride paste sol composition containing calcium carbonate.
It is added in the range of parts by weight.

The term "added at the time of kneading" refers to the time of kneading to mix a part or all of the vinyl chloride paste sol formulation when they are blended. This is added to a mixture of fine calcium carbonate, a vinyl chloride paste resin and the like, mixed and then kneaded as a vinyl chloride paste sol.

By adding the above-mentioned adsorbent substance, the storage stability under low-speed stirring becomes extremely good without impairing the original physical properties of the paste sol as compared with the case where the substance is not added.

Although the reason for this is not clear, these adsorbing substances are adsorbed on the surface of calcium carbonate or the surface of paste resin particles, and inhibit the chemical bonding between the two.
Even when stored under low-speed stirring, there is no opportunity for both to come in contact with each other, and it is considered that the formation of aggregates is prevented.

Accordingly, the storage stability is better as the amount of addition increases, but when the amount of the adsorbing substance is excessive, that is, when the amount exceeds 5 parts by weight with respect to 100 parts by weight of the calcium carbonate to be added, the adsorbing property is increased. Excess of the substance is released at the interface with the steel sheet, which impairs adhesion, strength and the like. On the other hand, when the addition amount is too small, that is, when the amount of the adsorbing substance is less than 0.05 part by weight with respect to 100 parts by weight of the calcium carbonate to be added, the effect is not exhibited because the amount of the adsorbing substance is small.

There is no particular limitation on the calcium carbonate to which the above-mentioned adsorbent substance is blended, and any heavy calcium carbonate or precipitated calcium carbonate may be used as long as it functions as a vinyl chloride paste sol. Or may be unprocessed,
Average primary particle size 0.5 when used for weight reduction
Precipitated calcium carbonate of μm or less is more preferred.

The fatty acid-based substances exemplified as the above-mentioned adsorbing substances are conventionally used as a surface treatment agent for calcium carbonate, but are not added during kneading as described above, but are added to the paste sol. Pre-treat calcium carbonate as a surface treatment agent in the usual way,
When dried and powdered and then mixed into a paste sol, the surface of calcium carbonate or paste resin cannot be uniformly coated, and the above-described effects are not recognized, and conversely, the adhesion is impaired.

In the present invention, the effect of the present invention can be further enhanced by using calcium carbonate treated with a sulfonic acid type organic acid. Examples of the sulfonic acid type organic acid used in the present invention include organic acids having a sulfone group such as dodecylbenzenesulfonic acid and condensed naphthalenesulfonic acid.
Used in combination of more than one species.

The amount of surface treatment is preferably from 0.01 to 5 parts by weight, more preferably from 0.1 to 3 parts by weight, based on 100 parts by weight of calcium carbonate. If the amount is less than 0.01 part by weight, the remaining alkali component cannot be completely neutralized and removed, and if it exceeds 5 parts by weight, calcium carbonate which has already been completely carbonated will be neutralized. Not only will the function of calcium carbonate be lost, but the cost will increase.

In the case of using precipitated calcium carbonate, the remaining alkali exposed on the surface is neutralized by surface treatment with a sulfonic acid type organic acid, and then dehydrated, dried and powdered in the usual manner. After kneading and defoaming, a vinyl chloride paste sol composition is obtained.

For the purpose of improving the dispersibility, the calcium carbonate surface-treated with a sulfone-type organic acid may be further treated with at least one selected from alkali metal salts of fatty acids and alkali metal salts of resin acids, if necessary. It can also be processed. As the alkali metal salt of a fatty acid, specifically, for example, capric acid (C10), myristic acid (C14),
Saturated fatty acids such as palmitic acid (C16), stearic acid (C18), behenic acid (C22), lindelic acid (C
12 '), zomaric acid (C16'), oleic acid (C
And alkali metal salts of unsaturated fatty acids such as sodium and potassium such as 18 ′), and these may be used alone or in combination of two or more. The surface treatment amount is suitably in the range of 0.01 to 5 parts by weight based on 100 parts by weight of calcium carbonate. The treatment of the two treatment agents is preferably performed in the order described above, but both may be performed simultaneously or in the reverse order.

The amount of the calcium carbonate surface-treated as described above is not particularly limited, but is, for example, 1 to 200 parts by weight based on 100 parts by weight of the vinyl chloride paste resin. If the amount is less than 1 part by weight, the effect of the present invention is not sufficiently exhibited, while if it exceeds 200 parts by weight, the resin component in the paste sol is reduced and the strength is inferior.

By mixing calcium carbonate surface-treated with a sulfonic acid type organic acid and at least one selected from alkali metal salts of fatty acids and alkali metal salts of resin acids, a vinyl chloride paste sol under low-speed stirring can be obtained. The reason that the storage stability of the composition is improved is that by neutralizing the calcium carbonate surface with a sulfonic acid type organic acid, the alkali component is not exposed on the calcium carbonate surface even after being compounded in the paste sol, Therefore, it is considered that by not forming an aggregate with the paste resin, the storage stability under low-speed stirring is improved without impairing the physical properties of the original paste sol. And the dispersibility of the surface-treated calcium carbonate is improved by the alkali metal salt of the fatty acid and the alkali metal salt of the resin acid,
It is considered that the above action is further promoted.

As described above, the calcium carbonate used in the present invention is preferably precipitated calcium carbonate. However, in order to more fully exert the effects of the present invention, a total amount of calcium carbonate containing calcium hydroxide as a main component is preferred. It is more preferred to use calcium carbonate with a reduced alkali residue. Calcium carbonate having a small residual amount of alkali can be obtained by the following method.

That is, the precipitated calcium carbonate is produced.
When using calcium hydroxide (Ca (OH)_Two) Water suspension
(Lime lime) concentration adjusted to 50-300g / L
And the lime milk temperature before conducting carbon dioxide gas is 5-20 ° C.
Range and Ca (OH) in the lime milk _Two7 to 35 ml / g
Of carbon dioxide gas (purity 100%), and a carbonation rate of 10
After reaching ~ 30%, reduce the amount of carbon dioxide gas
In other words, 0.01 to 1 ml /
Min, preferably 0.05 to 0.5 ml / min (purity 100
%), And then complete carbonation with an arbitrary gas flow rate.
Close.

7-35 until the carbonation rate reaches 10-30%
What is set to 1 g Ca (OH) ₂ is the amount of gas flow required for producing fine calcium carbonate of 0.5 μm or less in consideration of the function of the paste sol.
The setting of 1 to 1 ml / min · 1 g Ca (OH) ₂ is because the fine particles of calcium carbonate complete the carbonation in a short time due to the large gas flow, while a large amount of alkali remains, whereas the aggregated particles This is for removing as much as possible the alkali content contained therein.

By using the calcium carbonate having a small total alkali residue obtained in this way, various properties such as strength, viscosity and adhesion required for the vinyl chloride paste sol can be obtained under low-speed stirring. The storage stability can be improved more significantly.

The carbonation rate mentioned here is obtained by the following equation.

The total alkali residue in the dried calcium carbonate powder which has been completely carbonated by the above-mentioned method is the usual drying of the carbonated calcium carbonate until the completion of carbonation (until the pH becomes 7 or less) at the initial carbon dioxide gas flow rate. The total alkali residue in the powder is about 2% or more, while the alkali residue is surprisingly reduced to about 0.5% or less.

The total alkali residue was measured by the following method. "Measurement method of total alkali residue in calcium carbonate" About 50 ml of 0.2N Na ₂ CO ₃ was added to 5 g of sample, and the total amount was 20 with water.
Make 0 ml. After boiling for 30 minutes, suction filtration is performed, and the residue is washed with water. The combined filtrate and washings are first titrated with 0.3 N HCl using phenolphthalein as an indicator until the red color disappears (Aml). Next, a mixed indicator consisting of methyl orange and indigo carmine or methyl orange is added and titrated to the color change point (Bml). Na generated by the reaction
Since it contains OH and a residue of Na ₂ CO ₃ added in excess, it is separated and quantified by differential titration.

* (AB) ml · · HCl equivalent to NaOH 0.3 ml HCl / ml = 11.1 mg Ca (OH) ₂

[0039]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

In describing the examples and comparative examples, the composition of the vinyl chloride paste sol composition to be prepared is basically as follows. However, when an adsorbent substance is added to the composition, it depends on the timing of addition. Instead, a predetermined amount of calcium carbonate should be added separately from the basic formulation.
It was described in each case in Examples and Comparative Examples.

The method for preparing and evaluating the vinyl chloride paste sol composition was performed using the following equipment and conditions. (Blend) 100 parts by weight of vinyl chloride paste resin (Zeon 121, Japan) DOP 100 parts by weight Polyamide (Henkel Hakusui Corporation: DSX-140E) 10 parts by weight Solvent 5 parts by weight Calcium carbonate 70 parts by weight

(Method for Preparing Vinyl Chloride Paste Sol Composition) In the kneading, the compounds are sequentially compounded in a 3 liter stainless steel container in accordance with the above-mentioned compounding method, and while externally cooling with water,
Using TK Lab Disper (manufactured by Tokushu Kika Kogyo Co., Ltd.), the mixture was mixed at 3000 rpm for 30 minutes using 6 cm diameter dispers blades. In addition, when compounding other additives, it is basically added before compounding calcium carbonate, and when confirming the effect by changing the compounding order, it should be added by the method described separately in Examples and Comparative Examples. And The mixed product was dispersed for 30 minutes by a rake machine as described above. While kneading the mixed and dispersed product in a kneader (manufactured by Irie Shokai) at 24 rpm as described above, the mixture was defoamed by a vacuum pump for 30 minutes to obtain a vinyl chloride paste sol composition.

(Evaluation) Viscosity: The viscosities at 2.5 rpm and 20 rpm were measured at 20 ° C. using a BH type viscometer. Storage stability: 30 ℃ constant temperature room, concave shaped stirring blade 5rp
Under the condition of m, 800 ml of the prepared polyvinyl chloride paste sol was placed in a polyethylene 1 liter beaker,
Viscosity changes over time were compared by viscosity measurement, and the presence or absence of aggregates in the paste sol was visually evaluated. Adhesion: According to JIS A5758, an electrodeposited steel plate was used as an adherend, a tensile adhesion test was performed, and the peeling state at that time was evaluated by the ratio of cohesive failure to the whole.
The best condition for peeling is 100% cohesive failure.
The preparation of the test piece was performed according to the above-mentioned JIS preparation method, and the gelation of the paste sol was performed at 120 ° C. for 30 minutes.

Example 1 20 liters of lime milk having a Ca (OH) ₂ concentration of 100 g / l was put into a 30 liter stainless steel tank, the liquid temperature was adjusted to 15 ° C., and then the mixture was stirred at 120 rpm with a turbine blade to obtain 100% purity. The mixture was passed at a rate of 100 liter / minute of a CO ₂ mixed gas containing 30% of CO ₂ gas, and the reaction was completed when the liquid pH reached 6.9, to obtain about 2.6 kg of calcium carbonate. The average primary particle diameter of the product was 0.06 μm by an electron microscope photograph, and the total alkali residue measured by the above-mentioned measuring method was 2.3% by weight.

Commercially available industrial fatty acid comprising a sodium salt of a fatty acid containing 20% by weight of stearic acid, 40% by weight of oleic acid and 30% by weight of palmitic acid dissolved in this aqueous solution of calcium carbonate in warm water at 80 ° C. After adding 3% by weight of soap to the calcium carbonate and surface-treating, dehydration, drying and powdering were performed to obtain about 2 kg of calcium carbonate surface-treated with fatty acid soap.

At the time of kneading the vinyl chloride paste sol composition prepared by blending the surface-treated calcium carbonate thus obtained, 0.5 part by weight as an adsorbed substance is added to 100 parts by weight of the surface-treated calcium carbonate. Was added to prepare a vinyl chloride paste sol composition, and the composition was evaluated. The evaluation results are shown in Table 1. Good results were obtained for all items.

Example 2 20 liters of lime milk having a Ca (OH) ₂ concentration of 70 g / l was charged into a 30 liter stainless steel tank, the liquid temperature was adjusted to 20 ° C., and the mixture was adjusted to a purity of 1 with stirring at 120 rpm using a turbine blade.
The gas was passed at a rate of 100 liters / minute of a CO ₂ mixed gas containing 30% of 00% CO ₂ gas, and when the carbonation rate became 15%, the amount of gas passed was changed to 1 liter / minute.
The reaction was completed when the solution pH reached 6.9, and was approximately 1.4 kg.
Of calcium carbonate was obtained. The average primary particle size of the product was 0.09 μm by electron micrograph, and the total alkali residue was 0.48% by weight.

Example 1 was added to this aqueous calcium carbonate suspension.
1. Commercial industrial fatty acid soap used as a surface treating agent in 2.
By subjecting 5% by weight of the surface to dehydration, drying and powdering, about 1.2 kg of surface-treated fine calcium carbonate powder was obtained.

A vinyl chloride paste sol composition was prepared and evaluated in the same manner as in Example 1 except that the surface-treated calcium carbonate thus obtained was used. The evaluation results are shown in Table 1. As a result, better results were obtained than the results of the composition prepared in Example 1.

Comparative Example 1 A vinyl chloride paste sol composition was prepared and evaluated in the same manner as in Example 1 except that no adsorptive substance was added. The evaluation results are shown in Table 1. As shown in Table 1, the storage stability showed a remarkable decrease in viscosity, and the storage stability was poor.

Comparative Example 2 A vinyl chloride paste sol composition was prepared and evaluated in the same manner as in Example 1, except that the adsorptive substance added in Example 1 was changed to methyl stearate. The evaluation results are shown in Table 1.

[0052]

[Table 1]

[0053]

As described above, when the vinyl chloride paste sol composition of the present invention is used, for example, in the field of automobiles, it imparts high viscosity and high thixotropy, properties required for weight reduction. And, without lowering the other required physical properties, especially adhesion, improve the storage stability of the prepared polyvinyl chloride paste sol composition under low-speed stirring, that is, without causing a decrease in viscosity over time, agglomeration. It has good physical properties with almost no generation of matter. Thus, the compositions of the present invention, when used in the automotive field, make a significant contribution to the weight reduction faced by the automotive industry.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C09D 127/06 C09D 127/06 F term (Reference) 4J002 BD041 DE236 EF047 EF057 EN007 FB086 FB207 GH00 HA08 4J038 CD021 HA286 JA45 JC13 KA08 KA15 KA20 LA03 MA08 MA10 NA02 NA11 NA12 NA25 PB07

Claims (6)

[Claims] 1. A saturated fatty acid having 10 to 22 carbon atoms,
An adsorbent for calcium carbonate and / or vinyl chloride paste resin comprising at least one selected from the group consisting of amine salts of amine salts and amine salts of unsaturated fatty acids, comprising the calcium carbonate and vinyl chloride paste resin. A vinyl chloride paste sol composition added at the time of kneading the vinyl chloride paste sol. 2. The amount of the adsorbent added is 0.05 to 5 parts by weight based on 100 parts by weight of calcium carbonate.
A composition as described. 3. The composition according to claim 1, wherein the total alkali residue in the dry powder of calcium carbonate is 0.5% by weight or less. 4. The method according to claim 1, wherein the calcium carbonate is calcium carbonate 10
The composition according to claim 1, which is a surface-treated calcium carbonate treated with 0.01 to 5 parts by weight of a sulfonic acid type organic acid per 0 parts by weight. 5. The surface-treated calcium carbonate is composed of 0.01 to 5 parts by weight of a sulfonic acid type organic acid, an alkali metal salt of a fatty acid and an alkali metal salt of a resin acid, based on 100 parts by weight of the surface-treated calcium carbonate. The composition according to claim 1, wherein the composition has been surface-treated with 0.1 to 5 parts by weight of at least one selected from the group. 6. The composition according to claim 4, wherein the amount of the surface-treated calcium carbonate is 1 to 200 parts by weight based on 100 parts by weight of the vinyl chloride paste resin.