JPH05257224A - Glycoside surfactant as coating assistant for photographic layer - Google Patents

Abstract

PURPOSE: To improve solubility of a surfactant in gelatin or its aq. solution in a coating composition by adding to a composition, a specific surfactant used as a coating assistant and a nonionic or anionic auxiliary surfactant for completely dissolving the coating assistant surfactant into this composition. CONSTITUTION: The coating composition contains about 2.5 to 20wt.% of gelatin dissolved in water and about 0.05 to 0.5wt.% of a surfactant that is used as a coating assistant and represented by the formula, based on the weight of the coating composition in the form of a solution, and also contains a nonionic or anionic auxiliary surfactant for completely dissolving the coating assistant surfactant into this composition. In the formula: C6 H10 O5 is a glucose unit; (n) is an average value in the range of 9 to about 16; X is one of distributed values having an average value of 1 to 2. The amount of the auxiliary surfactant is adjusted to a value in the range of about 25 to 200wt.% of the amount of the coating assistant surfactant. Thus, by adding the glycoside surfactant to the coating composition contg. gelatin, surface tension of the composition can effectively be reduced to obtain a photographic coating layer having improved uniformity in thickness.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to surfactants as coating aids for gelatin coating solutions, especially for such solutions used in photography. The invention also relates to the use of long chain alkyl glycosides as coating aid surfactants for said solutions.

[0002]

In the manufacture of photographic materials, the support is usually coated with one or more layers of an aqueous solution of a hydrophilic colloid binder, such as gelatin. Examples of such layers include silver halide emulsion layers, intermediate layers, antihalation layers, filter layers, antistatic layers and protective layers. For the production of multilayer photographic materials, US Pat. Nos. 2,761,791 and 3,50
Multiple layers may be coated simultaneously on a conventional photographic support as described in US Pat. No. 8,947.

There are two main methods for coating photographic materials. One is the bead coating method; US Pat. Nos. 2,681,294, 2,761,
See 417 and 4,525,392.
These references describe the application of multiple layers of photographic material using the bead coating method and also describe the apparatus for carrying out this method. The second main method is the curtain coating method. U.S. Pat. No. 3,63
Nos. 2,372 and 4,569,863 describe coatings and apparatus for carrying out the method.

When forming a hydrophilic colloid thin layer of such a photographic material, a defect point (repellency spo) is formed.
It is necessary to coat the coating solution uniformly without forming ts) or craters (also called defects). Defect points are round, egg-shaped or broom-star-shaped notches or craters, or traces of partial healing after the formation of such disturbances. This type of imperfection is present in the coated layer when one layer is coated and in one or more layers when more than one layer is coated at the same time. .. Defect points are formed during the coating process or shortly thereafter, ie while the gelatin solution (or other hydrophilic colloid) in the coating is still fluid or mobile. These defects are usually due to additives,
Caused by the presence of small particles or droplets of insoluble material in the form of impurities or contaminants, such small particles being (i) in contact with the uppermost liquid-air interface of the coating layer and (ii) having surface activity In other words, they are capable of lowering the surface tension of the liquid-air interface of the isolated areas during the coating process.

The solutions that are coated during the manufacture of photographic materials are either dispersed insoluble photographic additives (which may include organic solvents), or additives for altering certain physical properties (lubrication). Agent and may include impurities in the lubricant), each of which may cause defects in the coating. Even photographic gelatin may contain insoluble residues of natural animal fats and fatty acids, which can cause defects in the coating layer. Also, surface active contaminants may be generated from external sources during the preparation or coating of the coating composition. For example, the coated layer, or the layer immediately after coating, may unintentionally be exposed to the droplets of lubricating oil used in the device.

When the gelatin coating composition is applied to a support such as a film substrate or photographic paper, a coating aid interface is provided in the coating composition to facilitate the application of the coating to the surface to be coated. It is preferred to have the activator present. In this sense, the compound used as the coating aid surfactant of the present invention is a compound effective for lowering the surface tension of a hydrophilic colloid-containing coating composition, for example, a gelatin-containing coating composition. The presence of the coating aid surfactant in the coating provides a layer of uniform or substantially uniform thickness when dried, having no or substantially no imperfections such as defects. Helps get the layers that don't.

Over the years, many compositions have been suggested for use as coating aids. In this regard, Research Disclosure Section XI, Issue 308 (198
(December 9), pages 993 to 1015 can be referred to.
However, relatively few water-soluble surfactants can be used extensively as coating aids. Because many of this type of surfactants are not very effective at controlling imperfections such as defects, have undesired photographic properties, and are less effective than these preferred surfactants. This is because very few have an ionic structure.

One category of nonionic saccharide coating aid surfactants described in the prior art are long chain alkyl ethers, esters and urethanes of saccharose, which saccharose is a surfactant molecule. It is a hydrophilic group. U.S. Pat. No. 3,507,660 to Nishio et al. Describes long-chain alkyl ethers of saccharose and urethanes as coating aid surfactants for photographic materials.
Haage et al., U.S. Pat. No. 3,516,833, describe long chain alkyl esters of sucrose as coating aid surfactants. Knox
U.S. Pat. No. 3,220,847 to Knox, U.S. Pat. No. 3,564,576, describes half esters of saccharose and alkyl succinic acids as coating aid surfactants. Long-chain alkyl esters of saccharose in combination with sodium maleopimarate are described as surfactant mixtures with good coating aid properties.

Surfactants of the type disclosed in this invention are listed in the materials taught to be useful with the coupler-containing compositions of US Pat. No. 5,013,640.

Prior art compositions as coating aids are also poorly water-soluble, poorly soluble in gelatin-containing solutions, and poor in their ability to minimize defect formation and thus their use. It was limited.

[0011]

Therefore, there is a need for new nonionic surfactants that have improved solubility in gelatin / water solutions as compared to prior art materials.

[0012]

SUMMARY OF THE INVENTION The present invention, as (i) water gelatin (or other hydrophilic colloid), and (ii) coating aid surfactant, wherein: C _n H _{2n + 1} -O- in _{(C 6 H 10 O 5)} x -H (I) wherein, based in parentheses represents the glucose unit, n represents an average value of up to 9, 10, 11, 12 and about 16,
x is a distribution value having an average value greater than 1 and less than 2, and (iii) an amount sufficient to completely or substantially completely dissolve said glycoside in the composition There is provided a composition comprising the anionic or nonionic cosurfactant of.

In a highly preferred embodiment, the composition constitutes the top layer of a co-coated multi-layer pack of photographic material, coated by the bead coating method. In another embodiment, the composition constitutes the top and / or bottom layer of a co-coated multilayer pack of photographic material coated by the curtain coating method. For purposes of the present invention, the "top" of a simultaneously coated multi-layer pack.
The layers, ie the "top layer" of a pack in which two or more layers are coated together, are defined as the layers furthest from the web. Similarly, the "bottom" layer of a co-coated multilayer pack is defined as the layer closest to the web. the term
"Web" means a manufactured film substrate or photographic paper substrate of concatenated length, pre-coated and dried layer,
For example, it includes an emulsion layer or an antihalation layer. In another embodiment, the composition comprises a single layer of photographic material (only one coated).

In the embodiment described in the immediately preceding paragraph, the layer with the coating aid surfactant of formula (I) may also contain silver halide and / or other imaging materials, or imaging It may not contain any material.
The layer comprising the composition may be a protective overcoat layer of one or more imaging layers coated on one or both sides of a web, for example a color or black-and-white film or photographic paper product. .. Alternatively, the layer comprising the composition may be a protective overcoat layer of a pelloid backing coating of a color film product or a black and white film product. The overcoat layer may contain other components normally present in such layers and known in the art. Alternatively, the layer comprising said composition is a layer other than the overcoat layer of a multilayer color photographic material, for example a non-imaging layer located between imaging layers, which comprises It may be obtained by sequentially applying two or more separate multi-layer packs in the manufacturing process.

In the present invention, glycoside surfactants are used as coating aid surfactants that are effective in reducing the surface tension of gelatin-containing coating compositions. The reduction of the surface tension of gelatin solutions by the addition of glycoside surfactants was reported by Wilhelmy.
It can be demonstrated by laboratory measurements of surface tension using the plate method. 110 ° F (43 in glass beaker
The surface tension of the non-deionized, lime-derived bone gelatin solution (70 g per liter) at a temperature of 40.degree. Has a surface tension of 28 dynes / cm.

In a preferred embodiment, the present invention comprises about 5 to about 12% by weight gelatin in water, and about 0.05 to about 0.3.
A composition is provided which comprises weight percent of the coating aid surfactant of formula (I) above. Thus, the compositions of this invention provide one or more layers of photographic material.

In another preferred embodiment, the invention provides a photographic material, such as a film or photographic paper, having at least one layer consisting of a dry layer formed from a coating or melt of the composition.

The compositions of this invention can be used with any gelatin used in photographic products, including calf bone gelatin derived from treatment with bases such as lime. However, the invention is not limited to such gelatin. In this regard, the usefulness of the present invention will be shown below with a composition based on acid-derived pig skin gelatin. This type of gelatin generally has a higher frequency of defects than the aforementioned calf gelatin.

It should be understood that, as indicated above, the present invention is not limited to gelatin-containing compositions. Therefore, the present invention can be extended to the use of the coating aids described above with compositions containing other suitable hydrophilic colloids derived from natural or synthetic materials. Examples of natural substances include proteins, protein derivatives, cellulose derivatives such as cellulose esters, polysaccharides such as dextran and gum arabic,
Materials such as zein, casein and pectin, collagen derivatives, agar, dwarf squad and albumin are mentioned. Examples of suitable synthetic hydrophilic colloids include polyvinyl alcohol, acrylamide polymers, maleic acid copolymers, acrylic acid copolymers, methacrylic acid copolymers and polyalkylene oxides.

The gelatin in the composition of the present invention may be hardened by any hardener known in the art. R for curing agents and their use
No. X of essearch Disclosure (supra)
It is described in the section. It should be understood that the presence or absence of a curing agent is not an important feature of the present invention.

The composition of the invention comprises a hydrophilic colloid, eg gelatin in water. Typically, the gelatin concentration in the coating composition to be applied to the photographic paper or film substrate support is about 2.5 to about 20% by weight gelatin. The top layer coating composition of the present invention comprises from about 5 to about 1
It is desirable to have 2% by weight gelatin.

In addition to the hardener and / or the reaction product of gelatin and hardener, the compositions of the present invention may contain other photographic chemicals normally included in photographic layers. For example, one top layer of a preferred embodiment of the present invention is an antistatic agent, a matting agent,
It may contain plasticizers, lubricants, and other materials not needed for imaging. Examples of matting agents include Rese
Section XVI of the Arch Disclosure (supra),
See Section XIII for antistatic agents and Section XII for plasticizers and lubricants.

As mentioned above, glycoside surfactants of the above type are used as coating aids in the formation of hydrophilic colloid layers. Preferably, the coating aid surfactant is used in an amount of 0.01 to 0.50, more preferably 0.05 to 0.30 wt% based on the weight of the hydrophilic colloid coating composition. The concentration range in which the coating aid is used depends on the cause of the defect point. The concentration range also depends on the presence of other surfactants in addition to the cosurfactant.

Preferred glycosides of the above general formula for use in the present invention are Henke.
APG G manufactured by l Corporation
It is commercially available as lycosides. Such glycosides are Henkel technical bul
It is described in lettins. Preferred APG glycosides are APG225, APG300 and APG325.
Glycosides.

The glycoside coating aid surfactants described above are generally preferred for use with the cosurfactant to enhance the solubility of the glycoside surfactant in the composition. For example, in a composition where gelatin is a hydrophilic colloid, the glycoside is mixed with a nonionic or anionic cosurfactant. Examples of such cosurfactants are nonionic long chain alkyl (6-18 carbon) aryl polyglycidol (5-20) ethers, and typical anionic surfactants are alkylsulfates, alkyls. Sulfonates, alkylaryl sulfonates, alkyl polyethoxy sulphates, alkylaryl polyethoxy sulphates, and alkylaryl polyethoxy sulphonates (these alkyl groups contain 6 to 18 carbons). ..

Generally, the amount of cosurfactant will be about 25 based on the weight of the glycoside coating aid surfactant.
Is about 200% by weight.

Photographic elements according to the present invention generally have at least 1
The layers comprise a light sensitive layer, for example a silver halide emulsion layer. This layer may be sensitized to a particular radiation spectrum using, for example, sensitizing dyes as are known in the art. Another light sensitive layer may be sensitized to other parts of the spectrum. These light sensitive layers may contain or combine dye forming compounds or couplers. For example, red-sensitive emulsions will generally be combined with cyan couplers, green-sensitive emulsions with magenta couplers, and blue-sensitive emulsions with yellow couplers. Other layers and additives, such as antistatic compositions, subbing layers, surfactants, filter dyes, protective layers, barrier layers, development inhibitor releasing compounds, etc., of the present invention are well known in the art. It can be present in a photographic element. Research Disclosure 1 for photographic elements and their various layers and addenda
7643 (supra) and James'"The Theory of the Phonog"
raphic Process "No. 4,1977.

The gelatin-containing layer of this layer and other layers in the element can be formed by any known coating method, such as curtain coating, roller coating, bead coating,
It may be coated by doctor blade coating, dip coating, air knife coating and the like. The layer is generally dried by simple evaporation, but drying may be facilitated by known techniques such as convection heating. Known coating and drying methods are Research
Disclosure 17643, December 1978 in more detail. In order to demonstrate the advantages of the coating aids of the invention compared to prior art surfactants, coating of a gelatin solution was performed using a narrow coater and the resulting coatings were: Visual tests were performed to compare the layer thickness uniformity. The purpose of the following examples was to use various gelatins in the top layer that had a strong tendency to form defect points. Coatings without coating aid surfactant in the top layer have a number of defects, and APG 300 or 325 in the top layer solution.
Defects were also observed in coatings containing only or the comparative compound saccharose laurate alone. However, when a mixture of APG 300 or 325 and a nonionic cosurfactant was added to the top layer, the resulting coatings contained sucrose laurate alone or in combination with a nonionic cosurfactant or sodium maleopimelate. The number of defect points was smaller than that of the coating. Details of the experiment are described below.

EXAMPLE 1 1 on a subbed polyester film support using a conventional multi-slide bead coating hopper.
Simultaneous three-layer coating was performed at a coating speed of 90 m per minute. An acid derived photographic grade pig skin gelatin (100 g / l solution) solution was prepared for the top layer. The intermediate layer is a solution of lime-derived bone gelatin in which the optical density of the intermediate layer is about 1.0 by adding dispersed carbon particles so that the uniformity of the layer thickness can be observed by visual inspection. Consists of. The bottom layer consists of a solution of lime-processed bone gelatin with no added carbon. The formation of defect points in the top layer during the coating process also disturbed the intermediate layer (containing carbon) and was visually observed to determine the number and size per unit area. Defect points were measured in two categories: large enough to be viewed without magnification and small enough to require 7x magnification. Table I shows the results of comparing various surfactants. In the absence of surfactant in the top layer solution, the coating shows numerous defects in both size categories. APG300 (0.1%) or APG3 on top layer
A number of defects were also observed in the coating with 25 (0.1%) only or with the comparative compound saccharose laurate (0.1%). A coating containing only 0.1 or 0.2% Surfactant 10G (used as a co-surfactant in other coatings) has a much lower number of defects but has the lowest number of defects under all conditions. The coating is
APG300 (0.1%) and Surfactant 10G (0.08 or 0.16) as co-surfactant
%) Or APG325 (0.1%) and Surfactant 10G as cosurfactant (0.
08 or 0.16%).
The mixture of glycoside coating aid surfactants and nonionic co-surfactants of the present invention provides for the coating during coating as compared to typical prior art surfactants alone or in admixture with sodium maleopimarate or Surfactant 10G. It was much more effective in suppressing the occurrence of defect points.

The materials used in this example are described below: (C) Sucrose monolaurate, representative comparative compound (prior art, US Pat. No. 3,516,833); the material used was GRILLOTEN LSE 65, RITA Corporati
on, PO Box 585, Woodstock, IL, 60098.

(A1) APG300 glycoside compound,
In formula (I), a mixture of n = 9, 10 and 11 and x
(X-bar) ~ 1.4 (Henkel product
literature). (A2) APG325 glycoside compound in the formula (I),
a mixture of n = 9, 10 and 11 and x (ex bar) to 1.6 (Henkel product literatur
e).

(B1) Oil Corporation
Surfactant 10G, manufactured by Surfactant, is a mixture of nonylphenoxypolyglycidol (5-14) ethers. (B2) Sodium maleopimarate (prior art, used in the mixture of US Pat. No. 3,564,576) is prepared by reacting maleic anhydride with pimaric acid and then neutralizing with sodium hydroxide. It is a manufactured compound.

[0033]

[Table 1]

Note 1. Weight% based on solution weight in top layer solution 1. Area of coating 0.46 m ² 3. ^3. Area of coating 310 cm ² 4. VH = extremely large number

[0035]

The glycoside surfactant used in the present invention improves the thickness uniformity, that is, the number of imperfections of defects in the layer is smaller, so that it can be used as a coating aid in a gelatin-containing layer for photographic materials. It is useful as an agent.

The present invention is believed to be a substantial improvement in the art. Glycoside surfactants of the type used in the present invention are readily available and therefore the present invention is readily industrially applicable.

Claims (4)

[Claims] 1. About 2.5 to about 20% by weight gelatin in water, and about 0.05 to about 0.5% by weight, based on the weight of the solution.
Of the formula: in _{C n H 2n + 1 -O- (} C 6 H 10 O 5) x -H Formula, C ₆ H ₁₀ O ₅ represents a glucose unit, n represents an average value of 9 to about 16 , And x is the distribution value (distr) having a mean value greater than 1 and less than 2.
and a non-ionic or anionic co-surfactant in an amount sufficient to completely dissolve the coating co-surfactant in the composition. A composition consisting of. 2. The amount of said cosurfactant is from about 25 to about 2 based on the weight of said coating aid surfactant.
The composition according to claim 1, which is 00% by weight. 3. A photographic material comprising a support having at least one layer comprising the dry coating composition of claim 1 on its surface. 4. A method of making a photographic material, the method comprising coating a layer having the composition of claim 1.