JP3040202B2 - Aqueous photosensitive resin composition and method for producing printed circuit board using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous photosensitive composition and a method for producing a printed circuit board using the composition. More specifically, the present invention relates to a photosensitive resin composition dissolved or dispersed in water to give an imageable coating film by developing with water or alkaline water after exposure, a method for producing the same, and a conductive metal layer. After applying the composition on a substrate having, dried to form a photocurable coating film, after performing exposure of a desired pattern on the film through a negative film or a positive film, developed with water or alkaline water The present invention relates to a method for manufacturing a printed circuit board, which comprises performing a process, and thereafter removing a conductive metal layer other than a pattern by an etching process.

[0002]

2. Description of the Related Art Conventionally, to make a printed wiring board,
Generally, after laminating a photosensitive film on a laminated board covered with conductive metal foil such as copper foil, further exposing and developing through a photographic negative, etching unnecessary copper foil other than circuit patterns Then, by removing the photosensitive film, a printed circuit is formed on the laminate, which is an insulator. In such a method, since the thickness of the photosensitive film used is generally thick, the circuit pattern formed by exposure and development is not sharp, and the photosensitive film can be uniformly laminated on the copper foil surface. It is difficult and the photosensitive film is expensive.

As another method for producing a printed wiring board, there is a method in which a liquid photosensitive resin composition is applied directly onto a substrate and dried to form a photocurable coating film. Is dissolved or dispersed in an organic solvent, and thus has a problem in working environment and the like caused by the organic solvent, and cannot be said to be widely used.

In recent years, the production of printed wiring boards by electrodeposition has attracted attention.
In addition to the need for expensive equipment, there are problems such as difficulty in managing the electrodeposition liquid.

The present invention is to solve the above-mentioned problems in the conventional method at once by providing a water-based photosensitive resin composition which gives an image-forming coating by developing with water or alkaline water after exposure. Things. That is, according to such an aqueous photosensitive resin composition, this is applied on a substrate,
Drying to form a photocurable coating film, on which a desired pattern is exposed through a negative film or a positive film, followed by development with water or alkaline water, and then a conductive metal layer other than the pattern Is removed by etching, and then the remaining resin coating is removed.
A printed circuit board can be manufactured without the above problems.

[0006]

Means for Solving the Problems The present inventors have developed a photosensitive resin composition containing a carboxyl group-containing resin, an amine compound, a photocurable unsaturated compound and a photopolymerization initiator.
Surprisingly, despite being capable of dissolving or dispersing in water, it is surprisingly coated and dried on a substrate, exposed to light and then developed with water or alkaline water to form an image, and acidic etching. The inventors have found that a photosensitive coating film having resistance to the liquid is given, and have completed the present invention.

That is, in one embodiment, the resin composition of the present invention comprises a carboxyl group-containing resin, an amine compound,
It is a water-based photosensitive resin composition containing a photocurable unsaturated compound, a photopolymerization initiator, and water as a solvent or a dispersion medium as essential components.

In another aspect of the present invention, a water-based photosensitive resin composition containing a carboxyl group-containing resin having a photopolymerizable unsaturated bond, an amine compound, a photopolymerization initiator and water as essential components. It is characterized by the following.

Further, in another aspect of the present invention, a water-based photosensitive resin composition containing a carboxyl group-containing resin, an amine compound having a photopolymerizable unsaturated bond, a photopolymerization initiator, and water as essential components. It is characterized by the following.

Although the photosensitive resin composition of the present invention having such a composition is water-based, that is, one which is dissolved or dispersed in water, it is unexpectedly coated on a substrate and dried, After that, it was found that a photopolymerizable coating film which can be formed by developing with water or alkaline water to form an image and which is resistant to an acidic etching solution is formed.

The carboxyl group-containing resin used in the composition of the present invention has a known acid value of 20 to 500, a number average molecular weight of 1,000 to 100,000, and a Tg of 0.
C. or higher is preferred. When the acid value is 20 or less, even if an amine compound is used, the affinity for water is poor, and it is difficult to obtain the aqueous photosensitive resin composition of the present invention. On the other hand, when the acid value is 5
If it exceeds 00, the affinity for water is too high, so that it is difficult to obtain a clear image by development with water or alkaline water. On the other hand, if the molecular weight is 1,000 or less, the strength of an unexposed photosensitive coating film obtained is low, and it is not preferred in that the photosensitive coating film is easily damaged in the exposure step and the like. On the other hand, the molecular weight is 1
If it exceeds 000, the viscosity of the composition is too high, so that problems such as dissolution and mixing are liable to occur, and problems such as a long development time in the development step occur. In addition, T
If the g is 0 ° C. or less, the composition becomes sticky, which is not preferable because it hinders operations such as exposure.

As the carboxyl group-containing resin in the present invention, for example, a resin obtained by copolymerizing an unsaturated monomer such as acrylic acid, esters of methacrylic acid and (meth) acrylic acid, styrene, (meth) acrylonitrile and acrylamide, or And those obtained by ring-opening an acid anhydride group of an acid anhydride group-containing resin such as a styrene-maleic anhydride polymer with water, an alcohol, an amine or the like.

As the alcohol used for ring-opening of the acid anhydride group of the acid anhydride group-containing resin such as a styrene-maleic anhydride polymer, a known alcohol can be used. From the viewpoint, primary or secondary alcohols are desirable. For example, methyl alcohol, ethyl alcohol,
Butyl alcohol, butoxyethanol, ethylene glycol monomethyl ether and the like can be used.
Further, as the amine used for the same purpose, a primary or secondary amine can be used. For example, ammonia, alkylamines such as diethylamine, monoethylamine, diisopropylamine and diisobutylamine, alkanolamines such as monoethanolamine and diethanolamine, alkylalkanolamines such as dimethylaminoethanol, and alicyclic amines such as cyclohexylamine Etc. can be used.

As the carboxyl group-containing resin in the composition of the present invention, those having a polymerizable unsaturated bond in the molecule are more preferably used. Such a resin can be synthesized by a known method, for example, by esterifying a part of the carboxyl group of the carboxyl group-containing resin with glycidyl acrylate in the presence of a catalyst. Further, it can be easily synthesized by using a known alcohol or amine having a polymerizable unsaturated bond as the alcohol or amine used for opening the acid anhydride group such as the styrene-maleic anhydride polymer described above. can do. Examples of the alcohol or amine that can be used for such a purpose include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, allyl alcohol, allylamine, and the like.

The resin composition of the present invention is characterized by containing an amine compound for the purpose of dissolving or dispersing the carboxyl group-containing resin in water. As the amine compound used for this purpose, a known compound can be used. For example, alkanolamines such as monoethanolamine, diethanolamine and triethanolamine, alkylamines such as triethylamine, diethylamine, monoethylamine, diisopropylamine and diisobutylamine, alkylalkanolamines such as dimethylaminoethanol, and fats such as cyclohexylamine Examples include cyclic amines and ammonia. More preferred amines used for this purpose include amines having a polymerizable unsaturated bond in the molecule. For example, dimethylaminopropylacrylamide, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, allylamine and the like can be mentioned. Among these amines, a boiling point of 100 is used in order to reduce the generation of amine odor in the coating and drying steps.
C. or higher is preferably used. The use amount of these amine compounds is 0.2 to 0.2 based on free carboxyl groups.
It is selected from a range of 2 moles.

The photocurable unsaturated compound contained in the composition of the present invention is a compound having at least two ethylenically unsaturated bonds in a molecule. Examples of such an ethylenically unsaturated compound include (meth) acrylates, allyl compounds, vinyl ether compounds, vinyl ester compounds, cinnamate compounds, and the like. As the (meth) acrylate, epoxy (meth) acrylate, polyvalent aromatic isocyanate, polyvalent aliphatic isocyanate and epoxy (meth) acrylate obtained from the reaction of a bifunctional or higher functional epoxy resin with a carboxylic acid having an ethylenically unsaturated bond.
Urethane (meth) acrylates obtained by reacting monohydric alcohol (meth) acrylate monoesters and polyhydric alcohol (meth) acrylates are exemplified. Examples of the allyl compound include diallyl esters such as phthalic acid, adipic acid and malonic acid. Examples of the vinyl ether compound include a vinyl ether compound of a polyhydric alcohol. Examples of the vinyl ester compound include divinyl succinate and divinyl phthalate. It goes without saying that a so-called monofunctional monomer having one ethylenically unsaturated bond can be used in combination. These photocurable unsaturated compounds are used in an amount of 0.2 to 3 times based on the total amount of the carboxyl group-containing resin used.

According to another aspect of the present invention, a carboxyl group-containing resin and / or an amine compound may be used in place of or in combination with the above-mentioned photocurable unsaturated compound, as described above. A composition having the same effect can also be obtained by using a polymerized unsaturated bond-introduced composition, that is, when coated and dried on a substrate, exposed and then developed with water or alkaline water to form an image. And a water-based photosensitive resin composition that forms a photocurable coating film that is resistant to an acidic etching solution.

As the photopolymerization initiator used in the composition of the present invention, all conventionally known photopolymerization initiators can be used. For example, benzophenones,
Benzoins, acetophenones, benzyls, benzoin alkyl ethers, benzylalkyl ketals, anthraquinones, thioxanthones and the like are preferably used. The mixing ratio of these photopolymerization initiators to the photosensitive resin composition is preferably 0.01 to 10% by weight based on the total composition.

It is preferable to appropriately use a polymerization inhibitor in the photosensitive resin composition of the present invention. As the polymerization inhibitor, all conventionally known inhibitors can be used, and preferred inhibitors include phenols, hydroquinones, and catechols. The mixing ratio to the photosensitive resin composition is 0.00% based on the total composition.
1-5% by weight is preferred.

In order to improve the dispersibility in water, a known surfactant can be appropriately added to the photosensitive resin composition of the present invention. For this purpose, anions,
Cationic or nonionic surfactants can be used.

The photosensitive resin composition of the present invention may further contain barium sulfate, silicon oxide, talc, clay,
Known fillers such as barium carbonate, known colorants such as phthalocyanine green and titanium oxide, dyes, leveling agents, adhesion improvers, thixotropic agents, plasticizers and the like can be added.

The aqueous photosensitive resin composition of the present invention can be easily prepared, for example, by the following method. However,
The methods described below exemplify typical methods for preparing the composition of the present invention, and the method of the present invention is not limited to these methods.

(1) A carboxyl group-containing resin or an acid anhydride group-containing resin is added to water containing an amine compound, heated and dissolved or dispersed in water. Add, mix and disperse the agents.

(2) A carboxyl group-containing resin or an acid anhydride group-containing resin is heated and dissolved in a photocurable unsaturated compound, and then a photopolymerization initiator is added, and water containing an amine compound is further added and mixed. I do.

(3) The acid anhydride group-containing resin is reacted with an alcohol or an amine in a photocurable unsaturated compound to open the acid anhydride group, and thereafter, a photopolymerization initiator is added, and the amine is further added. Add the water to which the compound was added and mix.

(4) The acid anhydride group-containing resin is reacted with an unsaturated alcohol or an unsaturated amine, if necessary, in a photocurable unsaturated compound to open the acid anhydride group and to allow the resin to have an unsaturated ring. After introducing a saturated bond, a photopolymerization initiator is added, and water containing an amine compound is further added and mixed.

(5) An acid anhydride-containing resin is reacted with a primary or secondary amine in water to open the acid anhydride group, and thereafter, an amine for dissolving or dispersing the resin in water, photocuring The unsaturated compound and the photopolymerization initiator are added and mixed.
These components to be added later may be added to the system in advance and the reaction may be performed in the presence of these components. Also,
An amine having a photocurable unsaturated bond may be used as an amine for opening the acid anhydride group and / or an amine for dissolving or dispersing the resin in water.

By the method as described above, the aqueous photosensitive resin composition of the present invention can be prepared without using a volatile organic solvent, but the viscosity of the resin composition is reduced to water. 5% volatile organic solvent, such as ethanol, based on the total composition to aid dissolution or dispersion of
The use of less than a small amount is within the scope of the present invention. Therefore, it should be understood that the aqueous photosensitive resin composition of the present invention includes those containing less than about 5% of an organic solvent based on the total composition.

The production of a printed circuit board using the aqueous photosensitive resin composition of the present invention is performed, for example, as follows.

The aqueous photosensitive resin composition of the present invention is coated on a substrate provided with a conductive layer such as a copper foil using a known apparatus such as a usual curtain coater, roll coater, screen coater, or electrostatic coater. And dried in a dryer. At this time, the aqueous photosensitive resin composition of the present invention does not contain a volatile organic solvent at all or contains a very small amount, so that no special measures or explosion-proof measures for the working environment are required, Also, a solvent recovery device or the like is not required in the drying step.

The resist image forming step is usually performed by exposure to light having a wavelength of 200 to 600 nm, as in the case of other conventional photosensitive resist materials. Preferred light sources include, for example, high pressure mercury lamps, metal halide lamps, xenon lamps, carbon arc lamps, chemical lamps, and the like. Development after exposure can be easily performed by a usual method using water or a dilute aqueous alkaline solution (for example, 1% aqueous sodium carbonate).

The etching for forming the circuit can be performed using a usual acidic etching solution, for example, an aqueous hydrochloric acid solution of cupric chloride. The removal of the resist film after the etching can be easily performed with a diluted alkaline aqueous solution, for example, 3% sodium hydroxide solution.

[0033]

The aqueous photosensitive resin composition of the present invention is surprisingly irrespective of being capable of being dissolved or dispersed in water and further containing an amine in the system. When coated on a substrate and dried, it is exposed to light and then developed with water or alkaline water to give a photosensitive coating film that can form an image and is resistant to an acidic etching solution. In addition, since the organic solvent is not contained at all or contains only a small amount, it is not necessary to take safety measures such as fire in the coating and drying steps, and there is little adverse effect on the working environment and the natural environment due to the organic solvent.

[0034]

EXAMPLES The present invention will be described more specifically below with reference to examples. In the following description, “parts” means “parts by weight”.
Represents

(Example 1) As a carboxyl group-containing resin, an aqueous acrylic resin "Carboset XL-27" (manufactured by BF Goodrich, USA, acid value 80, molecular weight 40,000)
13. 100 parts, triethylamine as an amine compound
4 parts and 330 parts of water were taken and heated at 70 ° C. to obtain a uniform and transparent solution. Trimethylolpropane triacrylate 33 was added to the resulting aqueous solution as a photopolymerizable unsaturated compound.
, 15 parts of 2,2-dimethoxy-2-phenylacetophenone as a polymerization initiator and 0.5 parts of hydroquinone monomethyl ether as a polymerization inhibitor were added, and the mixture was cooled to room temperature with stirring.

The obtained opaque creamy water-based photosensitive resin composition was applied to a separately prepared laminate having 18-micron copper foil on it using a doctor blade, and then coated with a doctor blade.
Drying at 5 ° C. for 5 minutes gave a dried film having a thickness of about 20 microns.

A negative film was brought into close contact with the obtained dried film, exposed to light using a high-pressure mercury lamp at a light quantity of 400 mJ / cm 2, and then spray-developed at 25 ° C. using a 1% aqueous sodium carbonate solution. A clear image-like resist film having a line width of up to 50 microns was obtained.

The copper-clad laminate having the resist film thus formed was immersed in an etching solution comprising 40 parts of anhydrous cupric chloride, 30 parts of concentrated hydrochloric acid and 50 parts of water at room temperature for 20 minutes. Except for the copper foil was removed by etching. No damage to the resist film was observed. Further, the thus obtained laminated board after etching is 3
Immersed in 1% aqueous sodium hydroxide solution for 1 minute at room temperature
The resist film could be easily peeled and removed, and a circuit board was obtained.

Example 2 In Example 1, dimethylaminopropylacrylamide 2 which is an amine having a photocurable unsaturated bond was used instead of 14.4 parts of triethylamine.
An opaque creamy water-based photosensitive resin composition was obtained in the same manner as described above except that 2.3 parts were used.

When coating, drying, exposure and development were performed under the same conditions as in Example 1, a resist image clearly reproduced up to a line width of 30 μm was obtained. Thereafter, in the same manner as in Example 1, the etching and the resist peeling after the etching could be performed without any abnormality.

Example 3 150 parts of a styrene-maleic anhydride copolymer (SMA-1000, styrene / maleic anhydride = 1/1, manufactured by SARTOMER, USA), 150 parts of trimethylolpropane triacrylate, butyl alcohol 54 Parts, dimethylaminopropylacrylamide 8 parts, N-butylbenzenesulfonamide 47 parts as a plasticizer, hydroquinone monomethyl ether 0.5
The mixture was heated and stirred at 80 ° C. for 2 hours to obtain a viscous substance. A surfactant (Emulgen 90) was added to the obtained viscous material.
3, Kao Corporation) 4 parts, 2,2-dimethoxy-2-phenylacetophenone (20 parts), ethyl alcohol (35 parts) as a solvent are added, and the mixture is cooled to room temperature. Further, dimethylaminopropylacrylamide (55 parts) is added to water (300 parts). The added solution was added with vigorous stirring.

The obtained aqueous photosensitive composition was applied to a separately prepared laminate having 18 μm copper foil covered with a doctor blade, dried at 100 ° C. for 5 minutes, and dried to a thickness of about 20 μm. A dry film was obtained.

A negative film was brought into close contact with the obtained dried film, exposed to light at a light intensity of 400 mJ / cm 2 using a high-pressure mercury lamp, and developed at 25 ° C. using tap water. A clear image-like resist film having a line width of up to 50 microns was obtained.

The copper-clad laminate having the resist film thus formed was immersed in an etching solution comprising 40 parts of anhydrous cupric chloride, 30 parts of concentrated hydrochloric acid and 50 parts of water at room temperature for 20 minutes. The copper foil was removed by etching except for the resist film without any damage. Further, when the thus obtained laminated board after etching was immersed in a 3% aqueous solution of sodium hydroxide for 1 minute at room temperature, the resist film could be easily peeled off and a circuit board was obtained.

Example 4 The procedure of Example 3 was repeated, except that 54 parts of butyl alcohol were used, and the ring-opening of the acid anhydride group was carried out in the resin.
A water-based photosensitive composition was prepared in the same composition except that 85 parts of hydroxyethyl acrylate were used for the purpose of introducing a heavy bond. Thereafter, application, drying, exposure and development with tap water were performed under the same conditions as in Example 3, and a resist image clearly reproduced up to a line width of 30 μm was obtained. Further, the etching and the resist peeling after the etching could be performed without any abnormality in the same manner.

Example 5 150 parts of styrene-maleic anhydride copolymer (SMA-2000, styrene / maleic anhydride = 2/1, manufactured by SARTOMER, USA), 150 parts of trimethylolpropane triacrylate, acid anhydride 28 parts of allylamine, 77 parts of dimethylaminoethyl methacrylate, 47 parts of N-butylbenzenesulfonamide as a plasticizer, and 0.1 part of hydroquinone methyl ether as an inhibitor for opening the group and introducing a photopolymerizable unsaturated bond into the resin. After stirring a mixture of 5 parts, 20 parts of 2,2-dimethoxy-2-phenylacetophenone and 300 parts of water at room temperature for 3 hours, the mixture was further heated and stirred at 80 ° C. for 1 hour to obtain an aqueous photosensitive composition.

The obtained composition was applied on a separately prepared 18 μm copper foil-coated laminate using a doctor blade, and dried at 100 ° C. for 5 minutes to form a dried film having a thickness of about 20 μm. Obtained.

A negative film was adhered to the obtained dried film, exposed to light at a light intensity of 200 mJ / cm 2 using a high-pressure mercury lamp, and then subjected to spray development at 25 ° C. using a 1% aqueous sodium carbonate solution. A clear image-like resist film having a line width of up to 30 microns was obtained.

The copper-clad laminate having the resist film thus formed was immersed in an etching solution comprising 40 parts of anhydrous cupric chloride, 30 parts of concentrated hydrochloric acid and 50 parts of water at room temperature for 20 minutes. The copper foil was removed by etching except for the resist film without any damage. Further, when the thus obtained laminated board after etching was immersed in a 3% aqueous solution of sodium hydroxide for 1 minute at room temperature, the resist film could be easily peeled off and a circuit board was obtained.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI C08J 3/075 G03F 7/027 C08L 101/08 7/033 G03F 7/027 H05K 3/06 H 7/033 C08J 3/03 H05K 3/06 (72) Inventor Katsue Nishikawa 2-29-302 Shimotsuruma, Yamato City, Kanagawa Prefecture (56) References JP-A-4-294354 (JP, A) JP-A-5-140251 (JP, A) JP-A-63-257748 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03F 7/038 C08F 2/48 C08F 291/00 C08F 299/00 C08J 3/03 C08J 3 / 075 C08L 101/08 G03F 7/027 G03F 7/033 H05K 3/06

Claims (16)

(57) [Claims] 1. A carboxyl group-containing resin, amine compounds, photocurable unsaturated compound, a photopolymerization initiator, and comprises water as a solvent or dispersion medium, the carboxyl group-containing resin
A water-based photosensitive resin composition which has no epoxy group, is coated on a substrate, dried and then developed with water or alkaline water after exposure to form an image having resistance to an acidic etching solution Stuff. 2. A carboxyl group-containing resin and an amine compound having a photopolymerizable unsaturated bond.
A composition according to claim 1. Wherein the carboxyl group-containing resin having a photopolymerizable unsaturated bond, an amine compound, a photopolymerization initiator, and comprises water as a solvent or dispersion medium, the carboxyl group-containing tree
A water-based photosensitive resin which is characterized in that the fat does not have an epoxy group, and which is coated on a substrate and dried, and after exposure, is developed with water or alkaline water to form an image having resistance to an acidic etching solution. Composition. 4. The composition according to claim 1, wherein the carboxyl group-containing resin is a resin obtained by ring-opening an acid anhydride group of an acid anhydride group-containing resin with an alcohol and / or a primary or secondary amine. . 5. The resin in which the carboxyl group-containing resin is obtained by ring-opening an acid anhydride group of an acid anhydride group-containing resin with an alcohol having a photopolymerizable unsaturated bond and / or a primary or secondary amine. Item 4. The composition according to item 2 or 3. 6. The method according to claim 1, wherein the carboxyl group-containing resin, the amine compound, the photocurable unsaturated compound and the photopolymerization initiator are mixed or dispersed in an aqueous medium. . 7. The method according to claim 6, wherein the carboxyl group-containing resin and / or amine compound has a photopolymerizable unsaturated bond. 8. The method according to claim 3, wherein a carboxyl group-containing resin having a photopolymerizable unsaturated bond, an amine compound, and a photopolymerization initiator are mixed or dispersed in an aqueous medium.
A method for producing the composition according to the above. 9. A method for forming a carboxyl group-containing resin by reacting an acid anhydride group of the acid anhydride group-containing resin with an alcohol and / or a primary or secondary amine to open the ring. Or the method of 7. 10. An acid anhydride group of an acid anhydride group-containing resin,
The method according to claim 7 or 8, comprising a step of forming a carboxyl group-containing resin by reacting with an alcohol having a photopolymerizable unsaturated bond and / or a primary or secondary amine to open the ring. 11. A method for forming a carboxyl group-containing resin by reacting an acid anhydride group of the acid anhydride group-containing resin with a primary or secondary amine in an aqueous medium to open the ring. Or the method of 7. 12. A carboxyl group-containing resin is obtained by reacting an acid anhydride group of the acid anhydride group-containing resin with a primary or secondary amine having a photopolymerizable unsaturated bond in an aqueous medium to open the ring. 9. The method of claim 7 or claim 8, comprising the step of forming. 13. A photocurable coating film formed by applying the aqueous photosensitive resin composition according to any one of claims 1 to 5 on an insulating substrate having a conductive metal layer, followed by drying. A method for manufacturing a printed circuit board, comprising: exposing a desired pattern thereon, performing a developing treatment with water or alkaline water, and thereafter etching the conductive metal layer other than the pattern with an etchant. 14. A carboxyl group-containing resin, an amine compound
Product, photocurable unsaturated compound, photopolymerization initiator, and solvent
Or a carboxyl group-containing resin containing water as a dispersion medium
Is, acrylic acid or methacrylic acid ester, styrene,
(Meth) acrylonitrile or acrylamic acid
Or the acid anhydride group of the acid anhydride-containing resin is
Also obtained by ring opening with alcohol or amine
Coating and drying on a substrate, characterized in that
After exposure, develop with water or alkaline water to
Water-based photosensitizers that form images resistant to chilling liquid
Resin composition. 15. The method according to claim 15, wherein the acid anhydride group-containing resin is styrene-male.
15. The composition according to claim 14, which is an acid anhydride. 16. A styrene-maleic anhydride resin comprising:
Acid number of 20-500, number of 1,000-100,000
Average molecular weight, glass transition temperature (T g)
16. The composition according to claim 15, wherein