JPS6169873A - Calcium carbonate filler - Google Patents

Abstract

PURPOSE:To provide a calcium carbonate filler for synthetic resin coating, etc. having excellent dispersibility, high degree of whiteness, high gloss, high strength and stability of viscosity, prepd. by allowing calcium carbonate to adsorb a sodium, ammonium or amine salt of a specified copolymer. CONSTITUTION:The filler is prepd. by adding 0.01-10pts.wt. sodium, ammonium and/or amine salt to 100pts.wt. (by solid) calcium carbonate for dispersion. The copolymer is obtained by copolymerization of (A) 90-100wt% monomer mixt. consisting of (a) 100pts.wt. alpha,beta-unsatd. monocarboxylic acid selected from among (meth)acrylic and crotonic acids, (b) 1-100pts.wt. alpha,beta-unsatd. dicarboxylic acid selected from among itaconic, maleic and fumaric acids and (c) 5-300pts. wt. polymerizable monomer selected from among alkyl ester of (meth)acrylic acid, (meth)acrylate with an alkoxyl group, etc. and (B) 10-0wt% other polymerizable monomers.

Description

Detailed Description of the Invention: "Industrial Application Field" The present invention relates to a reacidic acid additive, and more specifically, it has a wide range of uses such as various synthetic resins, organic solvent paints, water-based paints, rubbers, inks, and fillers for paper manufacturing. The present invention relates to a calcium carbonate salt agent that can be applied to various materials and can impart excellent properties such as hydration, whiteness, gloss, strength, and viscosity stability.

"Prior art""While the invention is trying to solve the problem! 1 point"
Carnoum carbonate is used for a variety of purposes, such as being useful as an extender in paints and as a conditioning agent for plastics.
Usually, extender pigment for paint, charcoal for filling plastics: I
As the 11 carunum, those having an average particle diameter of 20 μm or less, which generally exhibits pigment characteristics as large as L, are used. The average particle size of calcium carbonate herein refers to the size of one side calculated as a cubic crystal from the specific surface area determined by the BET method, and hereinafter simply referred to as "particle size", this particle size 2
Calcium carbonate with a diameter of 0 μm or less can be roughly classified into the following three types.

1a120-1 μm, To)1. o ~O1l/
7 m, (clO,l O ~ 0.01 μm Calcium carbonate that falls within the above range of fal mainly includes heavy calcium carbonate, which is anisotropic coarse particles with a particle size of about 20 to 4 μm, and light calcium carbonate, which has a particle size of about 4 to 1 μm. There are two types of calcium carbonate.

Calcium carbonate in this particle size range is used for plastics and paints!
! Although it has good dispersibility in plastics and paints as it is even if a special surface treatment is applied to improve dispersion when used in plastic compositions and paints, optical properties such as gloss of the coating film of plastic compositions and paints It has drawbacks such as poor properties and physical strength, and can only be used as an filler for brushes.

In addition, the colloidal carbonates belonging to the above range (c1) are
It is expected that if it can be sufficiently dispersed in plastics or paints, it will have excellent gloss and physical properties, but in reality, it has a high surface activity, so some kind of surface treatment is required. When dried and powdered, the particles often aggregate with each other to form secondary or tertiary aggregates.As a result, the gloss and physical strength are the same as when using calcium carbonate with a particle size of 111 m or more. Therefore, in order to prevent agglomeration between the calcium carbonate particles when drying and powdering the colloidal calcium carbonate, the carbonated water'f! A method has been adopted in which the surface of each particle is coated with calcium salts of higher fatty acids, resin acids, etc. by adding a solution of higher fatty acids, resin acid soda, dodecylbenzenesulfonic acid, and its alkali metal salts to the turbid liquid. ing. However, even with this method,
In addition, sufficient dispersibility could not be obtained and the expected tiIIJ% from the particle size could not be achieved in terms of gloss and physical strength. When used as an extender pigment in a paint, it tends to cause significant foaming during coating, which is undesirable.In particular, when used as an extender pigment in an emulsion paint, the viscosity stability over time deteriorates significantly.

On the other hand, calcium carbonate with a particle size of 1.0 to 0.1 μm in the above ibl does not have high surface activity and relatively low cohesiveness, so it has better performance compared to calcium carbonate with a particle size of ta1, (c1 It imparts optical properties, physical strength, etc.
Even with this, the optical properties and strength properties of plastic compositions, paints, etc. that use it are not necessarily satisfactory.

"Means for Solving the Problems" In response to the current situation, the present inventors have developed the above-mentioned fat particle size 20
Even when using calcium carbonate as a matrix with a particle size of about -1.0 μm, the gloss is significantly improved and the physical strength is also improved. Improves dispersibility even when using calcium carbonate as a matrix with lθ~0°01 μm, and accordingly improves gloss, whiteness, and physical strength.
Furthermore, the viscosity of the paint over time is extremely low, and the above-mentioned To
), even when calcium carbonate having a particle size of about 1.0 to 0.1 pm is used as a matrix, the gloss and whiteness can be further improved, and the physical strength can be further improved. As a result of repeated research with the aim of obtaining a calcium carbonate filler that could eliminate all of the drawbacks of the above, it was discovered that calcium carbonate adsorbed with a specific polycarboxylate could achieve this purpose. .

That is, the present invention provides calcium carbonate with (1) acrylic acid;
At least one α, β unsaturated monocarboxylic acid selected from methacrylic acid and crotonic acid [oo heavyits, (II)
At least one α, β unsaturated nocarpon derived from ichconic acid, maleic acid, and fumaric acid 1% tl-1o
o parts by weight, and (III) (a) acrylic acid alkyl esters and methacrylic acid alkyl esters, (b) acrylates and methacrylates having an alkoxy group, (
c) Acrylates and methacrylates having a noclohexyl group, (d) α, β monoethylenically unsaturated hydroxy esters, (e) polyalkylene glycol monoacrylates and monomethacrylates, (f) vinyl esters, (g) vinyl aromatics, (h) Unsaturated nitrile, (
111 having at least one type of polymerizable material selected from i) unsaturated dicarboxylic acid ester, (j) vinyl ether, (k) conjugated diene, chain olefin, and cyclic olefin.
90-100% by weight of a mixture consisting of 5-300 parts by weight
and at least one other polymerizable monomer 10-0
! % of the sodium salt, ammonium salt, and/or amine salt of the copolymerized copolymer based on 100 parts by weight of calcium carbonate solid content. The content is a calcium carbonate filler obtained by adding and adsorbing 1 part of O1-1offi.

In addition, since the above α,β-monoethylenically unsaturated carboxylic acid amide and sulfobase wa polymer have resistance to carunium ions and other polyvalent anhydrous ions, the calcium carbonate atoms of the present invention are added to a high concentration of 50% by weight or more. When supplying concentrated slurry in packaging form, it is advantageous to use a copolymer copolymerized with 10% by weight or less in order to improve the viscosity stability of the slurry over time. By adding it as a component, no particular improvement in the gloss, physical strength, viscosity stability, etc. of the plastic composition or paint can be expected, so there is no particular problem even if it is not added.

The calcium carbonate filler of the present invention is
Regardless of the particle size of calcium carbonate used as the base material, when comparing the same particle size, the degree of improvement in surface gloss is actually 15-20% or more compared to conventional surface-treated products. In addition, remarkable improvements are brought about in whiteness, physical strength, and paint viscosity stability.

In the present invention, calcium carbonate can be used without any particular restriction as long as it exhibits pigmentary properties and has a particle size of 20 μm or less, and may be selected as appropriate depending on the use and purpose. The above-mentioned calcium carbonate is adsorbed, and the term "adsorption" here includes a form of physical adsorption, such as a bond in which a carboxyl group in the above-mentioned copolymer and a calcium atom of calcium carbonate form a salt.

The salts of the copolymer that can be used in the present invention are as described above. I[I]
If the total amount of polymerizable monomers selected from fa) ~ (k+) is less than 90% by weight, the dispersion of calcium carbonate is likely to be inhibited. When used in paints, sufficient gloss cannot be obtained, and the viscosity stability of paints tends to deteriorate over time.Also, if the polymerizable monomer of (Ill) is less than 5 parts by weight, plastics , the whiteness of paint etc. tends to decrease significantly;
If the amount exceeds 1 part by weight, the solubility of the copolymer in water will significantly decrease, making it difficult to uniformly adsorb onto the individual surfaces of carunium carbonate (also, the foaming property of the paint will increase, and the viscosity will increase over time). Furthermore, the stability of
When the α, β unsaturated dicarboxylic acid in ■ is less than part of IN,
Because it is difficult to prepare a high degree calcium carbonate slurry of 40% by weight or more using the FC+ calcium carbonate, there are problems such as increased transportation costs and handling.
As a result, the carbonate powder of the present invention is limited to powder packaging, which not only limits its usage and is disadvantageous, but also prevents the use of the above-mentioned +c
Calcium carbonate (+) acts as an extender pigment in paints and significantly deteriorates viscosity stability over time. On the other hand, if the α,β unsaturated dicarboxylic acid in (2) exceeds 100 parts by weight, the high concentration water f! After adding the copolymer having such a composition to the suspension, it is ground by a wet grinder to produce the carunium carbonate filler having a particle size of (bl), which requires wet grinding. In the process of manufacturing or using the product, the viscosity in the wet pulverizer vessel increases significantly, causing the wet pulverizer to stop or break due to torque overload. Even if russoum carbonate is used in plastics, paints, etc., no particularly significant effects can be expected compared to the products of the present invention.

The number average molecular weight (measured by gel osmotic pressure chromatography (GPC)) of the copolymer used in the present invention depends on the type of component,
Although it varies depending on the composition ratio etc., it is usually 500 to 50,000, more preferably about 2,000 to 30,000.
When the molecular weight is less than 500, the adsorption rate tends to decrease,
Soo again.

If it exceeds 0, it will be difficult to produce the copolymer and the viscosity will increase significantly. Furthermore, when added to a calcium carbonate suspension, its agglomerative effect may make it difficult to uniformly adsorb onto the particle surface.

The above unsaturated monocarboxylic acids (and unsaturated dicarboxylic acids)
A copolymer consisting of a monomer (III) having polymerizability selected from II) and +a+ to (g)) can be obtained by a conventionally known method. For example, water, an organic solvent,
Another example is polymerization in a solvent such as a mixed solvent of a water-soluble organic solvent and water. In this case, persulfate, hydrogen peroxide, etc. are used as a polymerization initiator for polymerization in an aqueous medium. , an accelerator such as sodium bisulfite or ascorbic acid can be used in combination. For polymerization in an organic solvent, an azo compound or 18r machine is used as a polymerization initiator. l oxide etc. are used, and an accelerator such as imine compound can be used in combination. For polymerization in a mixed solvent of a water-soluble organic solvent and water, an appropriate polymerization initiator or a combination of a polymerization initiator and an accelerator can be selected from among the various polymerization initiators described above.

The copolymer thus obtained is treated with a sodium compound,
By neutralizing with an alkaline substance such as an ammonium compound or an organic amine, the sodium salt, ammonium salt, and amine salt of the desired copolymer can be obtained. The adsorption or coating amount of the copolymer salt on calcium carbonate is 0.01 to 100 parts by weight of calcium carbonate.
The amount is preferably 10.0 parts by weight, more preferably 0.1 to 5.0 parts by weight. When the amount of adsorption is less than 0.01 part by weight, the difference in treatment effect from the untreated product is not significant.

On the other hand, if it exceeds 10.0 parts by weight, the adsorption rate will decrease, and further significant improvements in appearance effects such as whiteness and gloss, as well as physical properties and strength cannot be expected, and it is often no longer economically advantageous. .

The calcium carbonate filler of the present invention is produced by a conventional method using the above-mentioned calcium carbonate and a salt of the copolymer, for example, calcium carbonate water 2. <Add at least one of the salts of the above copolymer to the liquid, mix uniformly by stirring, etc., allow the copolymer to adsorb onto the carbonate particles, dehydrate using a filter press, etc., dry, and dissolve. It can be produced by crushing and powdering it, or it can also be produced by fluidizing powdered calcium carbonate and spraying and adsorbing the aqueous solution of the copolymer onto this fluidized bed. . Furthermore, it is easy to supply calcium carbonate slurry in the form of packaging depending on the use and purpose. For example, an aqueous suspension of calcium carbonate is dehydrated using a filter press, etc., and the resulting press cake of calcium carbonate is mixed with the above-mentioned material. It is produced by adding a copolymer salt and stirring vigorously.

By adsorbing cough coexistence using these conventional methods,
Although the intended effects of the present invention are fully exhibited, if you want to obtain even greater effects, use a wet type dispersing machine such as a sand grinder mill, or a dry type using a dispersing machine such as a single ball mill. A preferred embodiment is a method in which the cough copolymer is adsorbed and then passed through the machine.

"Effects of the Invention" The calcium carbonate filler of the present invention thus obtained can be used not only in synthetic resins such as thermoplastic resins and thermosetting resins, paints such as organic solvent paints and water-based paints, but also in rubbers, inks, etc. It can also be effectively used as a paper-making filler, with excellent dispersion and
It provides properties such as whiteness, gloss, strength, and viscosity stability.

"Examples" The present invention will be explained in more detail below by giving Examples, Comparative Examples, Application Examples, and Application Comparative Examples! However, it goes without saying that the present invention is not limited in any way by these.

Implementation full 1 to 11 Milk of lime (containing ca (Oll)2 211.8%) with a ratio of FF 11.070 was prepared at 15°C, and the hydroxide power was
301/min carbon dioxide-containing gas per kg (including 25% C
02) to carry out the carbonation reaction, stop the carbonation reaction when the pH of the system is 8.0, stir for 10 hours at 55℃ and pH 10.0, and when the viscosity of the system reaches 2500 cps, carbonate gas is added again. Gas was passed through the system to bring the pH of the system to 6.9. As a result, the average particle size is 0.07μ, which has significantly less aggregate particles.
m of calcium carbonate (BET specific surface area 30rd/g) was obtained. A salt of the copolymer shown in Table 1 of the appendix was added to this aqueous suspension of calcium carbonate, and the copolymer was adsorbed onto the surface of calcium carbonate by stirring, followed by dehydration using a filter press and following a conventional method. , drying, and pulverization to obtain a calcium carbonate filler.

Example 12 An aqueous suspension of carium carbonate was prepared in the same manner as in Examples 1 to 11, and after dehydration by passing through a filter press, the same copolymer as used in Example 1 was added to the press cake. By adding 1.5 parts by weight of salt to 1.0 parts by weight of calcium carbonate solid content and vigorously stirring with a Lab Body Spar (manufactured by Tokushu Kika Kogyo), a solid concentration of 56% and 350 cp was obtained.
An ff1fi calcium filler consisting of a calcium carbonate slurry of s was obtained.

Comparative Examples 1 to 4 Calcium carbonate fillers were obtained in the same manner as in Examples 1 to 11, except that the salt of the copolymer adsorbed on calcium carbonate was changed to those shown in Table 1 of the appendix.

Comparative Example 5 The calcium carbonate aqueous suspension used in Examples 1-11 was dehydrated using a filter press, dried and pulverized in the usual manner to obtain a vL@calcium stimulant.

Comparative Example 6.7 The carboxylic acid salts adsorbed on calcium carbonate used in Examples 1 to 11 and Comparative Examples 1 to 5 were each mixed with 3 parts by weight of sodium stearate, 2 parts by weight of dodecylbenzenesulfonic acid, and 3 parts by weight of hydrogenated rosin methyl ester. A calcium carbonate filler was obtained by drying and pulverizing in the same manner as in the above Examples and Comparative Examples except that parts by weight were used.

Example 13 7 kg of heavy calcium carbonate powder Super #2000 (manufactured by Maruo Calcium) was mixed into a Henschel type super mixer SM.
V-20 (manufactured by Kakuda Seisakusho) was used to stir the powder until the temperature reached 120°C, and then the dispersant used in Example 2 was added to 0.
．． A calcium carbonate filler was obtained by adsorbing 5% by weight (solid/5solid).

Comparative Example 8 0.5% by weight of stearic acid (so
A carnoum carbonate filler was obtained in the same manner as in Example 13, except that the filler was changed to (lid/5olid).

Example 14.15 Carbonated water used in Examples 1 to 11! ! ! The suspension was made PHI O,O again with milk of lime, and was further left for 48 hours.
Stirring was performed at 5°C, and the average particle size was 0.20 μm (B
ET specific surface area fin? /g) After confirming that
Carbon dioxide gas was introduced again to make the pH 6.8.

This calcium carbonate was used to adsorb 0.8% of each of the dispersants used in Examples 2 and 4, followed by dehydration and drying to obtain a calcium carbonate filler.

Comparative Example 9 1.5% by weight of sodium stearate as a treatment agent for adsorption
A calcium carbonate filler was obtained in the same manner as in Examples 14 and 15 except for changing to (solid/5solid).

Application Examples 1 to 15, Application Comparative Examples 1-10 The calcium carbonate fillers obtained in Examples 1 to 15 and Comparative Examples 1 to 9, and heavy calcium carbonate #2000 (manufactured by Maruo Calcium) were used in the following formulations. A water-based paint was prepared, and the gloss and paint viscosity were measured.

The results are shown in attached Table 2.

Each measurement cost $1 as shown below.

Viscosity (1): B M type ductometer No. 3 and No. 40
(2) KV value (1) and (2) measured by Nystomer viscometer (Jinji Seisakusho). The viscosity after standing at 20°C for 1 day and after standing at 50°C for 7 days. Measure the viscosity of gloss: Apply the finished paint to a glass plate with a 4 ml doctor blade, and after one day at 20°C, the gloss (60'-6
0@) was measured [Paint formulation (PVC27% NV -39%)] (MI
LL BASE) Weight part dispersant A (Neugen E^-120 manufactured by Sokoso Lagure)
2 Dispersant B (Daiichi Kogyo Seika!!!8 Discoat N-14) Propylene glycol 50 Titanium white (Ishiya Sangyo R-630) 19
4 Calcium carbonate powder 6
5 (When using slurry, as calcium carbonate solid content in slurry) Water
52 (Including water in slurry when using slurry) (LET RO0-N) Old LL RASE
186 Emulsion (manufactured by Dainippon Ink)
222 Bonco) EC-821) Bral Cell Solp 35
"Blending method" Glass peas (Toshiba Ba C1+4
- Input 297ii parts of Nisei G11-503B>, 2
Grinding was performed for 0 minutes using a simple sand mill. Add the above emulsion and butyl cyanide solve to the mill base obtained in this way, and create a lab body spar (special mechanical chemical technology layer).
Stir at 11,000 rpm for 5 minutes! I did it III.

Application example! 6-18, Applied Comparative Examples 11-13 Implementation I2.
Using the calcium carbonate fillers obtained in Example 13, 4 and Comparative Example 5.8.9, polypropylene composite sheets were prepared by the following method, and their whiteness, gloss and tE4 strength were measured. The results obtained are shown in Table 3 below.

"Composition" Part by weight Polypropylene resin (Sumitomo Chemical +1-501) 80
'Calcium carbonate 2゜''
・Konbaito method” Electric roll surface temperature 230, kneading time 10 minutes “Test sheet”

Claims (1)

[Claims] 1. Calcium carbonate, (I) at least one kind of α, β selected from acrylic acid, methacrylic acid, and crotonic acid.
100 parts by weight of an unsaturated monocarboxylic acid, (II) 1 to 100 parts by weight of at least one α, β unsaturated dicarboxylic acid selected from itaconic acid, maleic acid, and fumaric acid, and (
III) (a) Acrylic acid alkyl ester and methacrylic acid alkyl ester, (b) Acrylate and methacrylate having an alkoxy group, (c) Acrylate and methacrylate having a cyclohexyl group, (d) α
, β monoethylenically unsaturated hydroxy ester, (e)
Polyalkylene glycol monoacrylate and monomethacrylate, (f) vinyl ester, (g) vinyl aromatic, (h) unsaturated nitrile, (i) unsaturated dicarboxylic acid ester, (j) vinyl ether, (k) conjugated diene, 90-100% by weight mixture of 5-300 parts by weight of at least one polymerizable monomer selected from chain olefins and cyclic olefins and 10-100% of at least one other polymerizable monomer Calcium carbonate-filled material is prepared by adding 0.01 to 10 parts by weight of a sodium salt, ammonium salt, and/or amine salt of a copolymer obtained by copolymerizing % by weight to 100 parts by weight of calcium carbonate solid content, and adsorbing the sodium salt, ammonium salt, and/or amine salt of a copolymer. agent. 2. The filler according to claim 1, wherein the other polymerizable monomer is at least one selected from α, β-monoethylenically unsaturated carboxylic acid amides, and sulfo group-containing monomers. . 3. The filler according to claim 1, wherein the copolymer added and adsorbed to calcium carbonate has a weight average molecular weight of 500 to 50,000.