JPS6048024B2 - Antistatic silver halide photographic material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an antistatic photographic material comprising at least one light-sensitive silver halide emulsion layer and at least one antistatic layer. It relates to photographic materials.

During the manufacture and use of photographic materials, static electricity tends to accumulate, and this accumulation of static electricity causes many problems.

This electrification occurs due to contact between the photographic material and rollers during manufacturing processes such as coating various film layers including the photosensitive layer and transportation during drying, or during winding and unwinding of the photographic material. This is caused by friction or peeling between the support surface and the emulsion surface, and also by peeling between the support and emulsion surface when the photosensitive material is exposed to high humidity that causes adhesion during use, and film This problem also occurs when a digital camera, automatic development of X-ray film, etc. are used. When these accumulated static electricity is discharged, the photosensitive material is exposed to light, and after the development process, irregular static marks such as spots, branches, and feathers are formed, which reduces the commercial value of the photographic material. There are things that can be seriously lost. These static marks are one of the most difficult problems because their existence is not known until they are developed. Furthermore, the accumulated static electricity causes dust to adhere to the surface of the photosensitive material, causing secondary failures such as uneven coating failures. Furthermore, since all photosensitive material supports are hydrophobic, static electricity accumulates to a large extent, and the occurrence of static marks increases as the processing speed and emulsion sensitivity increase, resulting in a significant adverse effect. Conventionally, various substances have been used to prevent charging of photographic materials.

These substances are ionic conductive substances or hygroscopic substances, and there is often a method that imparts conductivity to the photosensitive material and quickly dissipates the charge before discharge occurs due to charge accumulation. has been used. When used, these substances may be used alone or in combination. In order to directly impart antistatic properties to the support of photographic light-sensitive materials, it is known that such substances are directly blended into the polymeric material that is the support, or coated on the surface of the support. There is. In the latter case, a method is used in which an antistatic agent is applied alone or in combination with a polymeric substance such as gelatin, polyvinyl alcohol, cellulose acetate, polyvinyl formal, or polyvinyl butyral. In addition to the photosensitive emulsion layer provided on the support, the antistatic agent can be added to non-photosensitive auxiliary layers (for example, backing layer, antihalation layer, intermediate layer, protective layer, etc.). . Alternatively, there is a method of coating the developed photosensitive material to prevent dust from adhering to the developed photosensitive material during handling. By the way, known antistatic agents are highly sensitive. In the case of photosensitive materials having a high-temperature emulsion layer, there are few that exhibit satisfactory effects, especially under low humidity conditions, or there are cases where the antistatic effect deteriorates over time or adhesive failure occurs under high temperature and high humidity conditions. many. It was also added into the non-photosensitive auxiliary layer! The antistatic agent may diffuse into adjacent photosensitive emulsion layers, especially at high temperatures and high humidity, and may have adverse effects on photographic properties such as increased fog density, development inhibition, and decreased development density. Attempts have been made to use a high molecular weight polymer antistatic agent to prevent the diffusion of the antistatic agent, but in this case, the viscosity of the coating solution increases significantly during the coating process of the auxiliary layer to which the polymeric antistatic agent is added. Makes the application process difficult. On the other hand, if the coating process is improved by lowering the concentration of the coating liquid, the drying load will increase, making it necessary to increase the equipment for the drying process and reduce the transport speed of the coated material passing through the drying equipment. . Therefore, it has been difficult to apply polymer antistatic agents to photographic materials. The objects of the present invention are: firstly, the surface electrical resistance is low; secondly, the diffusion of the antistatic agent from the auxiliary layer containing the antistatic agent to the adjacent silver halide emulsion layer is small; and thirdly, the photographic properties are improved. It is an object of the present invention to provide an antistatic photographic material which has the following characteristics: no adverse effects, fourthly, little increase in viscosity due to the addition of an antistatic agent to the coating solution, and fifthly good film properties such as adhesion resistance. .

The object of the present invention is to obtain a polymer latex obtained by emulsion polymerization of at least one monomer selected from the following group A, 20 to 9 weight %, and at least one monomer selected from the following group B, 1 to a weight %. This was achieved using a silver halide photographic material characterized by having a surface area containing .

Group B: Monomers other than Group A, which have at least one vinyl group and are copolymerizable with Group A monomers. Group A monomers are monomers represented by the following general formula (1).

General formula (1) where R1: hydrogen atom or methyl group A: oxygen atom or -NH- R2: alkylene (2 to 10 carbon atoms), arylene (6 to 12 carbon atoms), alkylarylene (7 carbon atoms) ~13), M: hydrogen atom, alkali metal atom, ammonium ion Note that R2 may be substituted, and as a substituent,
Halogen atoms, hydroxyl groups and aryl groups (6 to 8 carbon atoms)
can be mentioned.

Further, R2 may be branched. Among the monomers of Group A, preferable monomers are, for example, acryloyloxyalkyl phosphate, (for example, acryloyloxyethyl phosphate, acryloyloxypropyl phosphate, 1-acryloyloxypropyl-2
-phosphate, 4-acryloyloxybutyl phosphate, acryloyloxyethoxyethyl phosphate, 1-acryloyloxy-3-chloropropyl-2
-phosphate, etc.), methacryloyloxyalkyl phosphate, (e.g. methacryloyloxyethyl phosphate, methacryloyloxypropyl phosphate, 1-methacryloyloxy-2-phosphate, 4-methacryloyloxybutyl phosphate, 1-
methacryloyloxy-3-chloropropyl-2-phosphate, 2-methacryloyloxyethoxyethyl phosphate, etc.), acrylamide alkyl phosphates (e.g., 2-acrylamidoethyl phosphate, etc.), methacrylamide alkyl phosphates (e.g., 2-methacrylamidoethyl phosphate, etc.) ,
Examples include vinylbenzyl phosphate.

Among these, acryloyloxyethyl phosphate, acryloyloxypropyl phosphate, metalloyloxyethyl phosphate, and methacryloyloxypropyl phosphate are particularly preferred.

Next, group B monomers will be described.

The group B monomer is not particularly limited as long as it has at least one vinyl group and is copolymerizable with the group A monomer, but examples include acrylic esters, methacrylic esters, acrylamides, allyl compounds, and vinyl ethers. esters, vinyl esters, vinyl heterocyclic compounds, styrenes, maleic esters, fumaric esters, itaconic esters, olefins, crotonic esters, and unsaturated nitriles.

Among these, acrylic esters, methacrylic esters, vinyl esters and styrenes are particularly preferred.
Examples of acrylic esters include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, Sec-butyl acrylate, amyl acrylate, hexyl acrylate,
2-ethylhexyl acrylate, octyl acrylate, 2-phenoxyethyl acrylate, 2-chloroethyl acrylate, dimethylaminoethyl acrylate, benzyl acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, phenyl acrylate, 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate , 2-hydroxypropyl acrylate, 2,3-dihydroxypropyl acrylate, ethylene glycol diacrylate, triethylene glycol acrylate, trimethylolpropane triacrylate, 2-methoxyethyl acrylate,
Mention may be made of 2-ethoxyethyl acrylate.

Examples of methacrylic acid esters include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, Sec.
-butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate,
Benzyl methacrylate, acetoacetoxyethyl methacrylate, chlorobenzyl methacrylate, octyl methacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, phenyl methacrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxypropyl methacrylate, ethylene glycol dimethacrylate, Examples include triethylene glycol methacrylate, trimethylolpropane monomethacrylate, pentaerythritol trimethacrylate, 2-methoxyethyl methacrylate, and 2-ethoxyethyl methacrylate. Examples of vinyl esters include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxyacetate, vinyl acetoacetate, vinyl benzoate, vinyl salicylate, vinyl chlorobenzoate, and the like. I can do it.

Examples of styrenes include styrene, methylstyrene, chloromethylstyrene, trifluoromethylstyrene, acetoxymethylstyrene, methoxystyrene,
Examples include chlorstyrene, dichlorostyrene, trichlorostyrene, divinylbenzene, and bromstyrene.

Examples of acrylamides include acrylamide,
Methylacrylamide, propylacrylamide, N-
Examples of acryloylpiperidine include allyl compounds such as allyl acetate and allyl benzoate, and examples of vinyl ethers include methyl vinyl ether and chloroethyl vinyl ether. It is preferred that at least one of the Group B monomers constituting the polymer latex of the present invention is water-insoluble. When there are two Group B monomers constituting the polymer latex, it is preferable that the larger monomer is water-insoluble.
Here, water-insoluble means that the solubility in water is 3% by weight or less. Regarding the copolymerization composition ratio of Group A and Group B, Group A monomer is 20 to 9 percent by weight, and Group B monomer is 1 to 8 percent by weight. From the viewpoint of stability etc., the A group monomer is 30~
It is preferable that the amount of the group B monomer is 8 percent by weight, and the amount of the group B monomer is 20 to 70 percent by weight, and particularly preferably the amount of the group A monomer is 30 to 6 percent by weight, and the amount of the group B monomer is 40 to 7 percent by weight.

For the synthesis of the copolymers of the present invention, British Patent No. 121103
Tan, Special Publication No. Sho 47-29195, Patent Application No. Sho 47-7174
No., Patent Application No. 1983-23466, Patent Application No. 1974-5974
No. 3, Special Patent Application No. 1984-31355, Special Application No. 1973-14
858 Eel, British Patent No. 961395, US Patent No. 27
No. 95564, No. 29144, No. 303383
No. 3, No. 3547899, No. 3227672,
Same No. 3290417, Same No. 3262919, Same No. 3
No. 245932, No. 2681897, No. 3230
No. 275, Canadian Patent No. 704778, Jiyoung,
Shi, Petropoulos et al., 1 Official, Digest. J(JOhnC.PetrOpOulOset
alOfficialDigest)? 719-736
(1961) 1 Introduction to Emulsion by Sadao Hayashi (1970)
), Soichi Muroi, 1 Polymer Lattezukes Chemistry J (197
0), Takuhiko Motoyama, 1 Vinyl Emulsion J (1965)
Journal of Science, Polymer, Chemistry, Edition J
OunalOfPOlymerScience, POly
rnerChemistryEditlOn)↓↓,2
It is convenient to carry out this process with reference to the method described in, for example, 089-2107 (1976).

It goes without saying that the polymerization initiator, concentration, polymerization temperature, reaction time, etc. can be varied widely and easily depending on the purpose. For example, to give one example, polymerization is generally carried out at 20-180°C, preferably 40-120°C. The polymerization reaction is usually carried out at a rate of 0.0 to the monomer to be polymerized.
5 to 5% by weight of a radical polymerization initiator and optionally 0.
It is carried out using 1-1% by weight of emulsifier. Examples of initiators include azobis compounds, peroxides, hydroperoxides, redox catalysts, etc., such as potassium persulfate, ammonium persulfate, tert-butyl peroctoate, benzoyl peroxide, isopropyl percarbonate, 2,4-dichloro Examples include benzoyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, dicumyl peroxide, azobisisobutyronitrile 2-2''-azobis(2-amidinopropane) hydrochloride, etc. Emulsifiers include anionic and cationic. In addition to amphoteric, amphoteric, and nonionic surfactants, there are also water-soluble polymers.

For example, sodium laurate, sodium dodecyl sulfate,
Sodium 1-octoxycarbonylmethyl-1-octoxycarbonylmethanesulfonate, sodium laurylnaphthalenesulfonate, sodium laurylbenzenesulfonate, sodium laurate, cetyltrimethylammonium chloride, dodecyltrimethylammonium chloride, N-2-ethylhexylpyridinium chloride , polyoxyethylene nonylphenyl ether, polyoxyethylene sorbitan lauryl ester,
Examples include polyvinyl alcohol. The size of the polymer latex of the present invention is not particularly limited, but is 0.01 to 0.
It is preferably 9μ, particularly 0.01 to 0.2μ.

Next, a specific synthesis example will be shown.

Synthesis Example 1 Synthesis of Exemplified Polymer Latex 1 A three-tube flask (1e) equipped with a thermometer, a nitrogen inlet tube, a stirring device, and a reflux condenser tube is placed on a steam bath.

2.5y of sodium nonylphenoxypolyoxyethylenepropanesulfonate ether is dissolved in 350ml of distilled water and injected.

Add to this 25f of n-butyl methacrylate! Add 25 dabs of 2-methacryloyloxyethyl phosphate and emulsify. Dissolve 0.8y of 2,2''-azobis-(2-amidinopropane) hydrochloride in 100ml of distilled water (this will be referred to as Solution A).

) This 112 is added after introducing nitrogen gas to replace the air in the flask and raising the temperature to 75°C, and stirring is continued. After about 1 hour, the remaining liquid A, 112, was added, and after another hour, all of the remaining liquid A was injected, and stirring was continued at 70°C for 1.5 hours, and then the temperature was lowered to reach the end point of the reaction. Synthesis Example 2 Synthesis of Exemplified Polymer Latex 11 350ml of distilled water was placed in the same reaction vessel as in Synthesis Example 1, and 30y(7)n-butyl methacrylate, 18
2-methacryloyloxyethyl phosphate (y) and divinylbenzene (2y) are added, and the temperature is raised to 75°C and stirred.

A solution 112 of Synthesis Example 1 was poured into this, stirring was continued for about 2 hours, and the remaining solution A 112 was added. After stirring for another 1 hour, add all of the remaining solution A and stir for 1.5 hours.
The temperature is lowered to reach the end point of the reaction. Preferred specific examples of the polymer latex used in the present invention include, but are not limited to, the following, and can be synthesized in the same manner as in the above synthesis example. Compound example (1) 2-methacryloyloxyethyl phosphate to n-butyl methacrylate copolymer (weight ratio 50:5
0) (2) 2-methacryloyloxyethyl phosphate to ethyl methacrylate copolymer (weight ratio 60:40
) (3) 2-methacryloyloxyethyl phosphate to n-butyl methacrylate copolymer (weight ratio 60:
40) (4) 2-methacryloyloxyethyl phosphate to n-butyl methacrylate copolymer (weight ratio 55
:45) (5) 2-methacryloyloxyethyl phosphate to ethyl methacrylate copolymer (weight ratio 65:
35) (6) 2-methacryloyloxyethyl phosphate styrene copolymer (weight ratio 35:65) (7) 2
-methacryloyloxyethyl phosphate bis(2
-methacryloyloxyethyl) phosphate n-butyl methacrylate copolymer (weight ratio 45:5:50)
(8) 2-methacryloyloxyethyl phosphate n-butyl methacrylate-styrene copolymer (weight ratio 50:30:20) (9) 2-methacryloyloxyethyl phosphate n-butyl methacrylate-vinyl acetate copolymer (Weight ratio 40:40:20) (10
2-methacryloyloxyethyl phosphate-ethyl methacrylate-1,1-dimethyl-3-oxobutylacrylamide copolymer (weight ratio 50:25:25) (
11) 2-methacryloyloxyethyl phosphate-n-butyl methacrylate-divinylbenzene copolymer (weight ratio 60:36:4) (12) 1-methacryloyloxypropyl-2-phosphate ethyl methacrylate copolymer (weight Ratio 35:65) (13) 1-methacryloyloxypropyl-2-phosphate n-butyl methacrylate-ethylene glycol dimethacrylate copolymer (weight ratio 40:55:5) (14) 4-methacryloyloxybutyl phosphate n- Butyl acrylate copolymer (weight ratio 60:40) (15) 2-acryloyloxyethyl phosphate to ethyl methacrylate copolymer (weight ratio 30:70) (16) 2-acryloyloxyethyl phosphate to n-butyl methacrylate copolymer Polymer (weight ratio 42:58) (17) 2-acryloyloxyethyl phosphate n-propyl methacrylate-diallyl isophthalate copolymer (weight ratio 52:45:3) (18) 2-acryloyloxyethyl phosphate Styrene-divinylbenzene copolymer (weight ratio 45:50:5) (19) 2-acryloyloxyethyl phosphate-n-butyl acrylate styrene copolymer (weight ratio 42:35:23) (20)
2-Acryloyloxyethylphosphate methyl methacrylate-1,1-dimethyl-3-oxobutylacrylamide copolymer (weight ratio 38:30:32) (2
1) 4-acryloyloxybutyl phosphate n-
Butyl methacrylate copolymer (weight ratio 30:70) (
22) 2-methacryloyloxyethyl phosphate to 2-acryloyloxyethyl phosphate to n-butyl methacrylate copolymer (weight ratio 30:10:60)
(23) 2-methacryloyloxyethyl phosphate acrylic acid-n-butyl acrylate copolymer (weight ratio 40:5:55) (24) Vinylbenzyl phosphate styrene-divinylbenzene copolymer (weight ratio 35
:55:10) The amount of the polymer latex of the present invention used varies depending on the type, form, coating method, etc. of the photographic material used.

However, in general, the amount used may be about 0.01 to 5.0 y per 1 d of photographic light-sensitive material, particularly 0.05 y.
~1.5y is desirable. In the present invention, the polymer latex is added to the surface layer of the silver halide photographic material, such as the surface protective layer, backing layer, and silver halide emulsion layer. In these surface layers, a binder such as gelatin, polyvinyl alcohol, cellulose acetate, or cellulose acetate phthalate may be used together with the polymer latex. A surface layer containing the polymer latex of the present invention! A particularly favorable effect can be obtained when a fluorine-based surfactant and a matting agent are used in combination.In particular, when a fluorine-based surfactant is used in combination, it is highly effective in preventing static marks.

Furthermore, the surface layer may contain various additives for purpose 3, such as a curing agent, a slipping agent, and an antihalation dye. Examples of matting agents that can be used in combination with the polymer latex of the present invention to obtain preferable effects include silver halide, barium strontium sulfate, polymethyl methacrylate, methyl methacrylate-methacrylic acid tetracopolymer, colloidal silica, and powdered silica. .

Furthermore, examples of the following compounds can be cited as fluorosurfactants that can provide a combined effect.

For example, British Patent No. 1330356, US Patent No. 3666
There are fluorine-based surfactants described in No. 478, No. 3589906, and the like. To give an example of a typical compound, for example, N-perfluorooctylsulfonyl-N-
Propylglycine potassium salt, 2-(N-perfluorooctylsulfonyl-N-ethylamino)ethyl phosphate, N-[4-(perfluorononenyloxy)benzyl]-N,N-dimethylammonioacetate, N
-)[3-(N″,N″,N″-trimethylammonio)propyl]perfluorooctylsulfonamide iodide, and N-(polyoxyethylenyl)-N-propylperfluorooctylsulfonamide (C8Fl7
SO2N(C3H7)(CH2CH2O)-H is mentioned. Supports to which the compound of the present invention can be applied include, for example, polyolefins such as polyethylene, polystyrene, cellulose derivatives such as cellulose triacetate, films such as cellulose esters such as polyethylene terephthalate, or baryta paper, synthetic paper, or paper. This includes supports made of sheets coated on both sides with these polymer films, and the like.

The silver halide photosensitive material according to the present invention may be a conventional black-and-white silver halide photosensitive material (for example, a black-and-white photosensitive material for photography,
-Black-and-white photosensitive materials for Ray, black-and-white photosensitive materials for printing, etc.), ordinary multilayer color photosensitive materials (e.g., color reversal films, color negative films, color positive films, etc.), and various silver halide photosensitive materials. be able to.

It is particularly effective for silver halide light-sensitive materials for high-temperature rapid processing and high-sensitivity silver halide light-sensitive materials. The present invention will be described below with reference to Examples, but it is not limited thereto. Example 1 A photosensitive emulsion layer and a surface protective layer having the following composition were sequentially coated on both sides of a subbed-treated polyethylene terephthalate film support (thickness: 180 μm) and dried to create samples 1 to 4. .

The composition of each layer is shown below. [Photosensitive emulsion layer] Binder Nigelatin 2.5y/d Coated silver amount: 7y/d Silver halide composition: Agll. 5 mol%+AgBr98
．． 5 mol% Hardener: 2-hydroxy-4,6-dichloro-s-triazine sodium salt 0.5f/100 da Binder Antifoggant: 1-phenyl-5-mermercaptotetrazole 0.5 da/AglOO datrimethylolpropane 5 y /AglOOy [Surface protective layer] Binder Nigelatin 2 da/i Hardener: 2-hydroxy-4,6-dichloros-triazine sodium salt 0.4 da/100 da Binder coating aid: Sodium dodecylbenzenesulfonate 28
m9/Rrl matting agent: 1.5 g/100 silica with an average particle size of 5p Dabinder Sample 1 consists only of the above composition, and sample 2 has the composition of 1 plus 0.5 g of compound 1 of the present invention in the surface protective layer. Da/Rrl
, Sample 3 similarly contains Compound 2 at 0.25 y/d, and Sample 4 similarly contains Compound 3 at 1 Da/d.

Evaluation of antistatic ability: Antistatic ability was determined by measuring surface resistivity and static mark generation. (1) Surface resistivity is measured using a test piece with an electrode spacing of 0.14d and a length of 10cm.
The test piece is placed between the electrodes made by Machiyu (the part in contact with the test piece is made of stainless steel), and the 1-minute value is measured using an insulation meter model TR865l made by Takeda Riken. (2) Static mark generation test is a method in which static marks are generated by placing an unexposed photosensitive material in the form of a rubber sheet with the antistatic agent-containing surface facing downward, pressing it with a rubber roller from above, and then peeling it off. The measurement conditions were as follows: surface resistivity was 25'C, 30%
The static mark generation test was performed at 25°C.
, 30% RH. The humidity of the sample test piece was maintained under the above conditions all day and night. To evaluate the degree of static mark generation, each sample was developed at 20° C. for 5 minutes using a developer having the following composition.

Developer composition N-methyl-p-aminophenol sulfur acid salt 4 da Anhydrous soda sulfite 60 da Hydroquinone 10 da Soda carbonate (monohydrate) 53f Potassium bromide 25f Add water to make 1e.

The evaluation of static marks was based on the following five-level criteria.

A: No static marks were observed. B: Some static marks occur. C: Significant static marks occur.

D: Significant static marks occur.

E: Static marks appear on the entire surface.

Table 1 shows the results of measuring the antistatic properties of these samples.

It can be seen from Table 1 that compounds 2-4 significantly improve the antistatic properties.

Example 2 A backing layer consisting of the following composition was coated on one side of a subbed-treated cellulose triacetate film and dried to produce backed bases 5 to 8, and then JP-A-51-30725 was applied to the opposite side of the support Similarly to Example 5 of the specification, samples Nos. 5 to 8 were obtained by coating an antihalation layer, a red photosensitive layer, a gelatin intermediate layer, a green photosensitive layer, a yellow filter layer, a blue photosensitive layer, and a protective layer in this order.

[Back layer]

Binder Nigelatin 4g / Coating agent: Sodium dodecylbenzenesulfonate) 10
mg/7712 Matting agent: Polystyrene particles with an average particle size of 4p 1.5 da/100g Binder The back layer of sample 5 consisted only of the above composition, and sample 6 contained the compound 1 of the present invention in addition to the above composition.
Sample 7 also contained compound 15 at 0.05y/i.
100y/d, and sample 8 also contained compound 24 at 1.5y/d.
Including d.

*3 Table 2 shows the evaluation of the antistatic ability of these samples. It is clear from Table 2 that compounds 11, 15, and 24 significantly improve antistatic properties.

Claims (1)

[Claims] 1. At least one monomer selected from Group A below,
An antistatic halogenated surface layer comprising a polymer latex obtained by emulsion polymerization of 20 to 99% by weight and at least one monomer selected from Group B below and 1 to 80% by weight. Silver photosensitive material. Group A: Monomer (I) represented by general formula (I) ▲ Numerical formula, chemical formula, table, etc. ▼ However, R_1: Hydrogen atom or methyl group A: Oxygen atom or -NH- R_2: Alkyl having 2 to 10 carbon atoms group, carbon number 6-12
arylene group, alkylarylene group having 7 to 13 carbon atoms, or -[(CH_2)_nO]_m(CH_2)_n-(m=
1 to 6, n=2, 3) M: hydrogen atom, alkali metal atom, or ammonium ion. However, R_2 may be substituted with a halogen ion, a hydroxyl group, or an aryl group. Group B: Monomers other than Group A, which have at least one vinyl group and are copolymerizable with Group A monomers.