JP2010043220A - Aqueous ink composition for ballpoint pen and ballpoint pen storing the composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous ink composition for a ballpoint pen capable of effectively suppressing excessive ink adhesion to paper even when low viscosity ink is used, and having excellent writing performance, and to provide a ballpoint pen storing the ink composition. <P>SOLUTION: The aqueous ink composition for a ballpoint pen includes a colorant, water and a specific cationic polyacrylamide and/or a specific cationic polymethacrylate. The cationic polyacrylamide and/or cationic polymethacrylate is included by 0.005 to 0.15 wt.% in the whole ink composition. The ballpoint pen stores the aqueous ink composition for the ballpoint pen. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a water-based ink composition for ballpoint pens and a ballpoint pen incorporating the same. More specifically, the present invention relates to a water-based ink composition for ballpoint pens in which surplus ink hardly accumulates at the tip of a pen during writing, and a ballpoint pen incorporating the same.

2. Description of the Related Art Conventionally, many ballpoint pens have been put on the market in which water-based ink for ballpoint pens is directly built in an ink storage tube, and a ballpoint pen refill provided with an ink backflow preventer at the rear end of the ink is stored in a shaft cylinder.
Among the above ballpoint pens, in order to obtain a smooth writing feeling, it is seen that the ink viscosity is set low, but when low viscosity ink is used, the ink discharged along with the rotation of the ball is excessively applied to the ball surface. The ink that spreads out and is not transferred from the ball to the paper surface is scraped off by the small tip of the ballpoint pen tip, and it is easy to generate a crying sticky that adheres to the paper surface after collecting on the outer surface near the tip of the small hole. Furthermore, in the retractable ballpoint pen, since the pen tip is accommodated in a state where ink is accumulated at the tip of the small mouth when not in use, there is a possibility that the ink falls and stains the surroundings.
Although the above-mentioned tearing can be suppressed to some extent by increasing the viscosity of the ink, there is a risk that the writing performance will be deteriorated, for example, the writing feeling becomes heavier due to the increase in viscosity, or the line breaks in the handwriting.
Therefore, even when using a low-viscosity ink, a technique for adding polyoxyethylene styrenated phenyl ether to water-based ink and a technique for adding etherified starch are disclosed in order to suppress the occurrence of crying. (For example, see Patent Documents 1 and 2).
However, the phenyl ethers and starches have problems such as low effect when added in a small amount and increase in ink viscosity when the added amount is increased to obtain a desired effect.
JP-A-10-195363 JP 2001-302958 A

  The present invention solves the above problems, that is, it can effectively suppress crying even with low-viscosity ink, and has a built-in water-based ink composition for ballpoint pens with excellent writing performance. To provide a ballpoint pen.

〔式（１）は分子量が５００万〜２０００万の範囲にあり、ｍ：ｎ＝９９：１〜６５：３５、ｐは自然数を示し、式（２）は分子量が５０万〜５００万の範囲にあり、ｐは自然数を示す。〕
更に、前記カチオン性ポリアクリルアミド及び／又はカチオン性ポリメタアクリル酸エステルがインキ組成物全量中に０．００５〜０．１５重量％の範囲で含まれること、前記インキ組成物の粘度が、２０℃、３０ｒｐｍでの回転粘度計による測定値が１〜２０ｍＰａ・ｓの範囲にあると共に、剪断減粘指数が、０．６〜１．０の範囲にあることを要件とする。
更には、前記いずれかのボールペン用水性インキ組成物を内蔵したボールペンを要件とし、前記ボールペンが０．７ｍｍ以上のボールを筆記先端部に備えること、前記ボールペンが、水性インキ組成物をレフィル内に内蔵したボールペンレフィルを１本又は複数本収容し、出没機構の作動によって前記ボールペンレフィルの筆記先端部が軸筒前端開口部から出没する出没式形態であることを要件とする。 The present invention is for a ballpoint pen containing a colorant, water, and a cationic polyacrylamide represented by the following general formula (1) and / or a cationic polymethacrylate represented by the following general formula (2). A water-based ink composition is a requirement.

[Formula (1) has a molecular weight in the range of 5 million to 20 million, m: n = 99: 1 to 65:35, p represents a natural number, and formula (2) has a molecular weight in the range of 500,000 to 5 million. And p represents a natural number. ]
Further, the cationic polyacrylamide and / or cationic polymethacrylic acid ester is contained in the total amount of the ink composition in the range of 0.005 to 0.15% by weight, and the viscosity of the ink composition is 20 ° C. The measurement value by a rotational viscometer at 30 rpm is in the range of 1 to 20 mPa · s, and the shear thinning index is in the range of 0.6 to 1.0.
Furthermore, it is a requirement for a ballpoint pen containing any one of the above-mentioned water-based ink compositions for ballpoint pens, the ballpoint pen is provided with a ball of 0.7 mm or more at the writing tip, and the ballpoint pen contains the water-based ink composition in the refill. One or a plurality of the built-in ballpoint pen refills are accommodated, and the writing tip portion of the ballpoint pen refill is in a retractable form that protrudes and retracts from the front end opening of the shaft cylinder by the operation of the retracting mechanism.

  According to the present invention, since it is possible to effectively suppress crying without increasing ink viscosity, a water-based ink composition for ballpoint pens that is particularly useful for low-viscosity inks and excellent in writing performance and a ballpoint pen incorporating the same are provided. It can be done. Further, since the pen tip is not accommodated in a state where the ink is accumulated in the pen tip, it is particularly useful for the ballpoint pen of the retractable type.

  The present invention suppresses the occurrence of crying by adding the cationic polyacrylamide represented by the general formula (1) and the cationic polymethacrylate represented by the general formula (2) to the ink. To do. This is because when the compound having a very large molecular weight is dissolved (dispersed) in the ink, it is entangled between the molecules, and the ink is transferred to the paper surface without scooping up the pen tip. Presumably because it is difficult to accumulate.

The cationic polyacrylamide or the cationic polymethacrylic acid ester can be added in an amount of 0.005 to 0.15% by weight, preferably 0.01 to 0.1% by weight, in the ink composition.
If it is less than 0.005% by weight, it is difficult to obtain the effect of suppressing crying, and even if it is added in excess of 0.15% by weight, the effect is not improved, so no further addition is required.

As the colorant, all dyes and pigments that can be dissolved or dispersed in an aqueous medium can be used, and specific examples thereof will be exemplified below.
As the dye, an acid dye, a basic dye, a direct dye, or the like can be used.
Examples of the acid dye include New Coxin (CI. 16255), Tartrazine (CI. 19140), Acid Blue Black 10B (CI. 20470), Guinea Green (CI. 42085), Brilliant Blue FCF. (CI.42090), Acid Violet 6B (C.I.42640), Soluble Blue (C.I.42755), Naphthalene Green (C.I.44025), Eosin (C.I.45380), Phloxin (C.I. 45410), erythrosine (C.I. 45430), nigrosine (C.I. 50420), acid flavin (C.I. 56205) and the like are used.

  Examples of basic dyes include chrysoidine (C.I. 11270), methyl violet FN (C.I. 42535), crystal violet (C.I. 42555), malachite green (C.I. 42000), Victoria Blue FB ( CI 44045), rhodamine B (C.I. 45170), acridine orange NS (C.I. 46005), methylene blue B (C.I. 52015) and the like are used.

  As direct dyes, Congo Red (C.I. 22120), Direct Sky Blue 5B (C.I. 24400), Violet BB (C.I. 27905), Direct Deep Black EX (C.I. 30235), Kaya Las Black G Conch (C.I. 35225), Direct Fast Black G (C.I. 35255), Phthalocyanine Blue (C.I. 74180) and the like are used.

Examples of the pigment include inorganic pigments such as carbon black and ultramarine blue, and organic pigments such as copper phthalocyanine blue and benzidine yellow, as well as water-dispersed pigments that are finely and stably dispersed in an aqueous medium in advance using a surfactant or the like. Products are used, for example
C. I. Pigment Blue 15: 3B [Product Name: S.P. S. Blue GLL, pigment content 22%, manufactured by Sanyo Dye Co., Ltd.]
C. I. Pigment Red 146 [Product Name: S.P. S. Pink FBL, pigment content 21.5%, manufactured by Sanyo Color Co., Ltd.]
C. I. Pigment Yellow 81 [Product name: TC Yellow FG, pigment content about 30%, manufactured by Dainichi Seika Kogyo Co., Ltd.]
C. I. Pigment Red220 / 166 [Product name: TC Red FG, pigment content: about 35%, manufactured by Dainichi Seika Kogyo Co., Ltd.].
As the fluorescent pigment, a fluorescent pigment in the form of fine particles of a synthetic resin in which various fluorescent dyes are formed into a solid solution in a resin matrix can be used.
Other examples include pearl pigments, gold and silver metallic pigments, luminous pigments, white pigments such as titanium dioxide used in correction pens, metal powders such as aluminum, fragrances, and fragrance capsule pigments.
In addition, when using a pigment, a pigment dispersant can be added as needed.
As the pigment dispersant, surfactants such as anions and nonions, anionic polymers such as polyacrylic acid and styreneacrylic acid, and nonionic polymers such as polyvinylpyrrolidone and polyvinyl alcohol are used.

The colorant can be used singly or in combination of two or more, and is used in the range of 0.01 to 15% by weight, preferably 0.1 to 10% by weight in the ink composition.

Examples of the water-soluble organic solvent include ethanol, propanol, butanol, glycerin, sorbitol, triethanolamine, diethanolamine, monoethanolamine, ethylene glycol, diethylene glycol, thiodiethylene glycol, hexylene glycol, 1,3-butanediol, and neoprene. Glycol, polyethylene glycol, propylene glycol, butylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoether Ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, sulfolane, 2-pyrrolidone, N- methyl-2-pyrrolidone.
The water-soluble organic solvent can be used alone or in combination of two or more.

In addition to the above components, alkyd resin, acrylic resin, styrene maleic acid copolymer, cellulose derivative, polyvinyl pyrrolidone, polyvinyl alcohol, λ-carrageenan, ι-carrageenan, methylcellulose, carboxymethylcellulose, carboxymethylcellulose within the category that does not impair drying resistance One or more water-soluble polymers such as alkali metal salts can be added.
In addition, a pH adjuster, a rust inhibitor, an antiseptic or an antifungal agent, a lubricant, and a wetting agent can be added as necessary.
Examples of the pH adjusting agent include inorganic salts such as sodium carbonate, sodium phosphate, sodium hydroxide and sodium acetate, and organic basic compounds such as water-soluble amine compounds such as triethanolamine and diethanolamine.
Examples of the rust inhibitor include benzotriazole and derivatives thereof, tolyltriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite, sodium thiosulfate, ethylenediaminetetraacetate, saponin, and dialkylthiourea.
Examples of the preservative or antifungal agent include carboxylic acid, sodium salt of 1,2-benzisothiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, 2, 3, 5, 6 -Tetrachloro-4- (methylsulfonyl) pyridine and the like.
Examples of the lubricant include higher fatty acids such as oleic acid, nonionic surfactants having a long chain alkyl group, polyether-modified silicone oil, thiophosphite tri (alkoxycarbonylmethyl ester) and thiophosphite tri (alkoxycarbonylethyl). Esters), phosphoric acid monoesters of polyoxyethylene alkyl ethers or polyoxyethylene alkyl aryl ethers, phosphoric acid diesters of polyoxyethylene alkyl ethers or polyoxyethylene alkyl aryl ethers, or metals thereof Examples include salts, ammonium salts, amine salts, alkanolamine salts, and the like.
Examples of the wetting agent include urea, nonionic surfactant, sorbit, mannitol, sucrose, glucose, reduced starch hydrolyzate, sodium pyrophosphate and the like.
In addition, an antifoaming agent such as a fluorine-based surfactant that improves the permeability of the solvent, a nonion, an anion, a cationic surfactant, or dimethylpolysiloxane may be added.

  When the ink composition is incorporated in an ink containing tube and used in a ballpoint pen of a type in which an ink backflow preventer is disposed on the rear end surface of the ink composition, if the gas is mixed in the ink, Bubbles gather to adversely affect ink ejection during writing, and if there are bubbles at the tip of writing, writing may become impossible, so ascorbic acid, ascorbic acid derivative, erythorbic acid, ersorbic acid derivative, α -Tocopherol, catechin, catechin derivative, synthetic polyphenol, kojic acid, alkylhydroxylamine, oxime derivative, α-glucosyl rutin, phosphonate, phosphinate, sulfite, sulfoxylate, dithionate, thiosulfate, Chemistry with addition of thiourea dioxide, formamidinesulfinic acid, glutathione, etc. It is preferable to remove the bubbles.

If desired, a shear thinning agent such as water soluble or dispersible xanthan gum, welan gum, succinoglycan whose constituent monosaccharide is an organic acid-modified heteropolysaccharide of glucose and galactose (average molecular weight of about 100 to 100) 8 million), guar gum, locust bean gum and its derivatives, hydroxyethyl cellulose, alginic acid alkyl esters, polymers having a molecular weight of 100,000 to 150,000 based on alkyl esters of methacrylic acid, seaweeds such as glucomannan, agar and carrageenan Thickening polysaccharides having gelling ability, benzylidene sorbitol and benzylidene xylitol or their derivatives, crosslinkable acrylic acid polymer, inorganic fine particles, polyglycerin fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyethylene Nonionic surfactants such as glycol fatty acid esters, polyoxyethylene alkyl ethers / polyoxypropylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, fatty acid amides and the like having an HLB value of 8 to 12, salts of dialkyl or dialkenylsulfosuccinic acid, etc. It can be exemplified, and can be used alone or in combination.
Furthermore, a mixture of N-alkyl-2-pyrrolidone and an anionic surfactant, a mixture of polyvinyl alcohol and an acrylic resin can also be used.
Ink shear thinning is a rheological property that has high viscosity and is difficult to flow in a static state or when stress is low. It means liquidity, also called property or pseudoplasticity.

When the viscosity of the ink of the present invention is in the range of 1 to 20 mPa · s at 20 ° C. and 30 rpm, the shear thinning index is in the range of 0.6 to 1.0 (so-called low viscosity ink) ) Is more useful.
Compared to inks with high physical viscosity and low shear thinning index, the physical properties of the ink are more likely to cause crying at the time of writing, so that it can work more effectively and suppress crying, and writing performance, It is possible to satisfy good handwriting formation such as writing feeling, handwriting line cracking and drying property.
The shear thinning index is derived from rheological measurement of the shear stress value (T) and the shear rate (j) value by a viscometer, and an empirical formula (T = Kj ^n, where K is calculated. N value calculated by applying (constant).

The ball-point pen containing the water-based ink composition of the present invention can be applied in any of a cap type and a protruding type.
As a cap-type ballpoint pen, an ink storage tube to which a ballpoint pen tip is connected directly or via a connecting member is used as a shaft cylinder (outer shaft) or a refill (which is stored in the outer shaft), and ink is stored in the ink storage tube. Directly housed can be applied.
As the ink containing tube, a metal processed body or a resin molded body made of a thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate or the like is used. In addition, in the said resin-made ink storage pipe | tube, an ink color, ink remaining amount, etc. can be confirmed by using a transparent, colored transparent, or translucent molded object.

A general-purpose pen is used as an intrusion type ballpoint pen without limiting its structure and shape, and one or more (so-called multi-core writing instruments) ballpoint pen refills are placed in the shaft cylinder with the writing tip exposed to the outside air. And has a structure in which the writing tip portion protrudes from the shaft tube opening by the operation of the retracting mechanism.
Examples of the operation method of the retracting mechanism include a knock type, a rotary type, and a slide type.
The knock type has a knock portion on the rear end portion of the shaft tube and the side surface of the shaft tube, and by pressing the knock portion, the writing tip portion of the ballpoint pen refill is projected and retracted from the front end opening portion of the shaft tube, or on the shaft tube. The structure which makes the writing tip part of a ball-point pen refill appear and disappear from the axial cylinder front-end opening part by pressing the provided clip part can be illustrated.
The rotary type has a rotating part at the rear part of the shaft cylinder, and can be exemplified by a configuration in which the writing tip part of the ballpoint pen refill is projected and retracted from the front end part of the shaft cylinder by turning the rotating part.
The slide type has a slide part on the side surface of the shaft cylinder (inside the window hole), and the writing tip of the ballpoint pen refill is projected and retracted from the front end opening of the shaft cylinder by operating the slide, or provided on the shaft cylinder. A configuration in which the writing tip portion of the ballpoint pen refill is projected and retracted from the front end opening portion of the shaft cylinder by sliding the clip portion can be exemplified. Moreover, as a slide-type writing instrument, the multi-core writing instrument of the structure which can replace | exchange the refill of the state connected with the said slide part from a window hole rear end etc. can be illustrated.

The ball-point pen tip (writing tip) is formed, for example, by cutting a metal to form a ball receiving seat and an ink lead-out portion inside, and a plurality of inward protruding portions on the inner surface near the tip of a metal pipe from the outer surface. Can be applied between the inward projecting portions, and an ink outflow gap extending radially outward from the central portion can be applied. The contact area is relatively small, and a smooth writing feeling can be given at a low writing pressure.
The ball held by the ballpoint pen tip is 0.1 to 2.0 mm in outer diameter of cemented carbide, stainless steel, ruby, ceramic, etc., preferably 0.3 to 1.6 mm, more preferably 0.7 to A 1.6 mm ball is effective, and the moving distance in the radial direction between the inner diameter of the ball holding portion of the chip and the ball is in the range of 10 to 50 μm, and the moving distance in the axial direction of the ball is in the range of 10 to 30 μm. preferable.
The ballpoint pen tip is provided with a resilient member for projecting the rear end of the ball forward in the tip, and when not writing, the ball is pressed against the inner edge of the tip of the tip to bring it into close contact, and when writing, it is The ball can be retracted so that ink can flow out.
Examples of the elastic member include a metal thin wire spring, a member provided with a straight portion (rod portion) at one end of the spring, a linear plastic processed body, and the like, and can be pressed by an elastic force of 10 to 40 g. Applied.

The back end of the ink stored in the ballpoint pen refill can be filled with an ink backflow prevention body.
The ink backflow prevention body composition is composed of a non-volatile liquid or a hardly volatile liquid.
Specifically, petroleum jelly, spindle oil, castor oil, olive oil, refined mineral oil, liquid paraffin, polybutene, α-olefin, α-olefin oligomer or co-oligomer, dimethyl silicone oil, methylphenyl silicone oil, amino-modified silicone oil, Examples thereof include polyether-modified silicone oil and fatty acid-modified silicone oil, and one or more can be used in combination.

It is preferable to add a gelling agent to the nonvolatile liquid and / or the hardly volatile liquid to increase the viscosity to a suitable viscosity. The surface of the silica is hydrophobized, the surface is methylated fine particle silica, and aluminum silicate. , Swellable mica, hydrophobic thickeners such as bentonite and montmorillonite, fatty acid metal soaps such as magnesium stearate, calcium stearate, aluminum stearate, zinc stearate, tribenzylidene sorbitol, fatty acid amide, amide modified Examples include dextrin compounds such as polyethylene wax, hydrogenated castor oil, fatty acid dextrin, and cellulose compounds.
Furthermore, the liquid ink backflow prevention body composition and a solid ink backflow prevention body composition can be used in combination.

Examples will be described below, but the present invention is not limited to these examples.
The composition of the water-based inks of Examples and Comparative Examples, viscosity, and shear thinning index are shown in the following table. In addition, the numerical value of a composition in a table | surface shows a weight part.
The ink viscosity of each example and comparative example was measured at 30 rpm using a B-type rotational viscometer [manufactured by Tokyo Keiki Co., Ltd.] at 20 ° C. Further, the shear thinning index is a value calculated from the measured value of each ink viscosity.

The contents of the raw materials in the table will be described along the note numbers.
(1) Orient Chemical Industry Co., Ltd., C.I. I. Direct Black 154, trade name: FISCO BLACK 886 (15% active ingredient)
(2) Eisen Hodogaya Co., Ltd., C.I. I. 45410, trade name: Phloxine (3) manufactured by Sumitomo Chemical Co., Ltd., C.I. I. 42655, Product Name: Acid Blue PG
(4) Made by MT Aqua Polymer Co., Ltd., trade name: Aron Flock 1310N (molecular weight about 7 million, m: n = 95: 5)
(5) Made by MT Aqua Polymer Co., Ltd., trade name: Aron Flock 3150 (molecular weight about 10 million, m: n = 75: 25)
(6) Made by MT Aqua Polymer Co., Ltd., trade name: Aron Flock 1600 (molecular weight about 2 million)
(7) Taiyo Kagaku Co., Ltd., trade name: Sankara 634
(8) Product name: Rubiscol K-30, manufactured by BASF
(9) Daiichi Kogyo Seiyaku Co., Ltd., trade name: Prisurf AL, polyoxyethylene distyrenated phenyl ether phosphate monoester and diester mixture (10) 1,2-benzthiazolin-3-one, avicia ( Product name: Proxel XL-2
(11) Product name: Cyprogum F-500, manufactured by Nissho Chemical Co., Ltd.

Preparation of ink The raw materials described in each Example and Comparative Example were mixed, stirred with a disper at room temperature, and then filtered to prepare an ink.

Ballpoint pen refill The ballpoint pen refill consists of a ballpoint pen tip (which contains a ball push spring that bounces the ball forward) and a ballpoint pen tip fixed to the front. The connection member, the connection member fixed to the front end opening, and the ink storage tube in which each ink and the ink backflow preventer are stored, and the rear end opening of the ink storage tube It consists of a tail plug. The ink backflow preventer is an ink backflow preventer kneaded using polybutene as the base oil and fatty acid amide as the thickener.

Manufacture of a ballpoint pen The sample ballpoint pen has a clip formed on the outer surface of the rear portion of the shaft cylinder, and each ballpoint pen refill is accommodated in a rearward biased state by a coil spring inside the shaft cylinder. The ballpoint pen tip protrudes to the outside from the tip hole of the shaft cylinder by knocking the operation portion forward.

The following tests were conducted with each of the ballpoint pens.
Crying proof test A sample ball-point pen that has been confirmed to be writable can be written on a JIS P3201 writing paper A continuously with a spiral circle (100m) using an automatic writing tester. Was observed visually.
The tester was used under the conditions of a writing load of 100 g, a writing angle of 65 °, and a writing speed of 4 m / min.

The test results are shown in the following table.

The contents of the test result evaluation symbols are as follows.
○: There is no crying in the handwriting, and there is no ink accumulation at the tip of the tip.
Δ: Ink pool is observed at the tip of the chip.
X: Crying botting is recognized in the handwriting.

Claims (6)

A water-based ink composition for ballpoint pens containing a colorant, water, and a cationic polyacrylamide represented by the following general formula (1) and / or a cationic polymethacrylic acid ester represented by the following general formula (2) .

[Formula (1) has a molecular weight in the range of 5 million to 20 million, m: n = 99: 1 to 65:35, p represents a natural number, and formula (2) has a molecular weight in the range of 500,000 to 5 million. And p represents a natural number. ]   The aqueous ink composition for ballpoint pens according to claim 1 or 2, wherein the cationic polyacrylamide and / or cationic polymethacrylic acid ester is contained in the total amount of the ink composition in the range of 0.005 to 0.15% by weight. .   The viscosity of the ink composition is a value measured by a rotational viscometer at 20 ° C. and 30 rpm in the range of 1 to 20 mPa · s, and the shear thinning index is in the range of 0.6 to 1.0. Item 3. A water-based ink composition for ballpoint pens according to item 1 or 2.   The ball-point pen which incorporated the water-based ink composition for ball-point pens in any one of the said Claims 1 thru | or 3.   The ball-point pen according to claim 4, wherein the ball-point pen has a ball of 0.7 mm or more at a writing tip.   The ball-point pen contains one or more ball-point pen refills with a water-based ink composition incorporated in the refill, and the writing pen tip portion of the ball-point pen refill protrudes and retracts from the front end opening of the shaft cylinder by the operation of the retracting mechanism. The ballpoint pen according to claim 4 or 5.