KR910001523B1 - Photosensitive coating composition - Google Patents

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Description

[Name of invention]

코 coating composition comprising a susceptible polymer and a process for producing the polymer

Detailed description of the invention

The present invention relates to a photosensitive resin composition. Even more specifically, the present invention can be used alone to provide a photosensitive adhesive film or to increase the susceptibility to light or resins for removing tackiness, crosslinking agents for increasing the crosslinking density, for example, various other types of components, A photosensitive resin composition for forming a protective coating film of excellent properties, which can be mixed with another photosensitive component. The use of the photosensitive coating material according to the present invention thus includes application to photoresists such as plating resists, corrosion resists and solder masks.

Solder masks are used for the production of printed wiring boards. The solder mask basically prevents the soldering of the bridge and maintains electrical insulation between the conductors, preventing conduction between the soldering areas and preventing corrosion of bare copper conductors. It is also desirable to provide a light-imaging solder mask capable of retaining an image that can be used as a blueprint on which the solder is placed (an image can be formed by light). Since it is desirable to increase the wiring density, it is desirable to use a solder mask having precise resolution and extremely good electrical insulation. The photosensitive composition of the present invention can provide these advantages.

Known solder masks are described in US Pat. No. 4,499,163 which discloses free radicals in urethane diacrylates or dimethacrylates, straight chain polymer compounds having a glass transition temperature of about 40 ° -150 ° C. and actinic radiation. There is shown a photosensitive resin composition containing a sensitizer. Among the linear polymer compounds described herein include polymers made from vinyl series straight chain polymers or copolymers such as methyl methacrylate, butyl methacrylate, methyl styrene, vinyl toluene and the like. Examples of sensitizers for generating free radicals include substituted and unsubstituted multinuclear quinones.

Another photocurable urethane acrylate resin composition that can be used as a permanent resist can be found in US Pat. No. 4,587,201. The composition described in this patent uses a urethane-acrylate resin made of a polybutadiene polymer. This resin is combined with a photopolymerization initiator to form a permanent resist material.

However, most photo-imaging solder masks lack the ability to be developed in aqueous solutions. This requires the use of an organic solvent developing solution. The use of such organic solvents is undesirable due to environmental regulations for solvent spinning control.

Another drawback found in solder masks using organic solvent developers is that the final product continues to be susceptible to organic solvents such as methylene chloride. Moreover, in the application of certain products, such susceptibility is undesirable.

Therefore, it is desirable to develop a photo-imaging solder mask coating composition that can be developed in aqueous solution and resistant to organic solvents such as methylene chloride. One object of the present invention is to provide such a coating composition. It is another object of the present invention to provide a solder mask coating composition that can be stripped with a commercial alkali stripper. Thus, the photosensitive resin composition described herein has excellent resolution, flexibility, metal adhesion, solvent resistance, high temperature resistance, and electrical insulation.

According to a specific embodiment of the composition there is provided a very viscous photosensitive material useful as an additive to a composition requiring thickening and the addition of the photosensitive coating material. Thus the photosensitive material fulfills a dual role as a thickener and as a photosensitive photocurable additive. Such embodiments of the present invention are thus useful photosensitive, photocurable thickeners for materials such as paints, inks and the like.

The photocurable coating composition comprises a ＵＶ sensitive compound selected from carboxylated urethane diacrylate, carboxylated urethane triacrylate, carboxylated urethane dimethacrylate and carboxylated urethane trimethacrylate. This group will now be referred to as carboxylated urethane di (and / or) tri (meth) acrylates. It will be appreciated that the (meth) acrylates here represent acrylates and / or methacrylates.

Such carboxylated urethane di / and or tri (meth) acrylates are prepared from acidifying components that provide carboxyl groups. These compositions are prepared by condensing diisocyanates, carboxylic acid polyols and hydroxyalkyl (meth) acrylates. Carboxylic acid polyols should be present in an amount necessary to provide at least about 0.3 milliliter equivalents of acid per gram of total reactant. In this specification we will use the abbreviation meq per gram of TR (typically the total reactant which is a diisocyanate, carboxylic acid polyol and hydroxyalkyl (meth) acrylate). In order to obtain a suitable level of photosensitivity in this product, hydroxyalkyl (meth) acrylate is about 0.5 milliequivalents per gram of the sum of diisocyanate, carboxylic acid di- or triol and hydroxyalkyl (meth) acrylate Should be used in minimum quantities.

There are several embodiments of the present invention made by combining the coating composition with other components specially selected. Among those components selected to provide or enhance certain qualities or characteristics include binders, crosslinkers, dyes, pigments, thermal polymerization inhibitors and additives made to improve coating properties.

The thermosetting coating composition of the present invention contains a carboxyl moiety that alters the lipophilic properties of the urethane (meth) acrylate polymer. As a result, the coating composition of the present invention becomes more oleophobic and thus resistant to organic solvents such as methylene chloride. Furthermore, these carboxylated photosensitive polymers can be mixed in large amounts with other hydrophilic binders and crosslinkers. In addition, the introduction of the carboxyl moiety causes the coating composition of the present invention to dissolve or expand in an aqueous alkali solution (pH of 7.5 or higher) until exposed to X-rays. Advantageously, when the composition of the present invention is used to provide photocurable coatings or solder masks, the developing step can be carried out in an aqueous alkali solution. As such, the introduction of the carboxyl moiety alters the properties of the urethane (meth) acrylate so that it becomes soluble in aqueous alkalis, but retains the susceptibility to X-rays of this compound. Moreover, carboxylation promotes adhesion to metals. Thus, an improved solder mask is provided by a combination of a binder, a crosslinking agent and a carboxylated urethane di (and / or) tri (meth) acrylate. Preferred combinations are those using copolymers of styrene / maleic anhydride as binders (providing carboxyl groups). Preferred crosslinkers are (meth) acrylates and polyfunctional (meth) acrylate monomers.

Preferred carboxylated urethane di (and / or) tri (meth) arylenes of the present invention may be represented by the general formula of the formula:

N is an integer of 1-4; k can be 0 or 1; R ₇ derived from the acrylate reactive moiety (c) may be hydrogen or methyl; R _2, also derived from an alkyl (di or tri) (meth) acrylate reactive component (c), may be a straight or branched chain saturated hydrocarbon moiety having ₂ to 28 carbon atoms; R ₃ is derived from the diisocyanate portion of the reaction mixture. R ₃ is branched, straight or cyclic; It may be a saturated, unsaturated or aromatic hydrocarbon moiety. R ₃ preferably has 4-20 carbon atoms, and more preferably 6-18 carbon atoms. In other preferred embodiments R ₃ is derived from a diisocyanate reactant selected from trimethylhexamethylene, hexamethylene, isophorone, tolylene, 4,4 methylbis (cyclohexyl) methylenediphenyl and tetramethylxylene diisocyanate. R ₄ is straight, cyclic or branched; As aromatic, saturated or unsaturated hydrocarbons, it preferably has 2-28 carbon atoms. Optionally R ₄ may contain a hydroxyl moiety (remaining from the polyol used in the preparation of the composition). R ₅ will be derived from (a) a carboxylic acid polyol as shown in formula (2) or (b) a carboxylic acid polyol as shown in formula (2) and a hydroxyl dicarboxylic acid as shown in formula (3).

Thus R ₅ will always have at least one COOH moiety and at least three carbon atoms. If R ₅ is derived from (a) (ie only derived from the compound of formula 2) it will have only one COOH group and the branched chain black is straight chain; It is saturated, unsaturated or aromatic and preferably will have a total of 3-30 carbon atoms, including carboxyl carbon atoms. When R ₅ , is derived from (b), the entire composition will have an R ₅ portion derived from hydroxyl dicarboxylic acid of formula 3 in addition to the R ₅ portion derived from carboxylic acid polyol of formula 2. The R ₅ moiety derived from the hydroxyl dicarboxylic acid compound of formula 3 will apparently have two COOH groups and may have 3-30 carbon atoms, including two carboxyl carbons. Techniques given for the compounds of Formulas 2 and 3 will provide more information about the preferred structure and concentration of these R ₅ moieties.

The exact location of each R ₅ moiety in the polymer molecule will depend on the number of reactive hydroxyl groups of the compound of Formula 2 or Formula 3, and to some extent on the random condensation reaction. For example when R ₅ is derived from (b) and when y in formula 3 is 1, R ₅ will be an end group having two COOH moieties; At the same time other R ₅ moieties (derived from the carboxylic acid polyol of formula 2) from the same reaction mixture will be randomly located in the backbone of the polymer molecular structure indicated earlier in formula (1).

(여기서 m=1 또는 2)로 이루어진 군에서 선택된 부분이다.R ₂ in formula 1 preferably has 2-16 carbon atoms, even more preferably ethyl, propyl, butyl and

(Wherein m = 1 or 2).

R ₄ is derived from any polyol that can be added to the reaction mixture. Thus R ₄ will have 2 to 28 carbon atoms and 2 to 5 oxygen atoms. Oxygen atoms may be in the unreacted hydroxyl moiety. When R ₄ is present R ₄ has 2-28, preferably 2-16 carbons and optionally a hydroxyl moiety. In another preferred embodiment are saturated or unsaturated hydrocarbons having 2-10 carbon atoms and 2-5 oxygen atoms, perhaps in the form of unreacted hydroxyl groups. In a specific example of the same preferred embodiment, R ₄ is selected from ethyl, propyl, butyl, pentyl, hexyl, heptyl and octyl and has 2-5 oxygen atoms from the previous hydroxyl moiety. R ₄ may also be derived from glyceryl or 2-ethyl-2- (hydroxymethyl) -1, 3-propylene.

The carboxylated urethane di (and / or) tri (meth) acrylates of the present invention can be obtained by condensing diisocyanates, carboxyl polyols (see Formula 2) and hydroxyalkyl (meth) acrylates in a one-step reaction. . The carboxyl-containing polyol may be any carboxylic acid containing two or more hydroxyl moieties. Suitably there are 2-5 hydroxyl groups. Preferred are carboxylic acid diols or triols.

Thus, the carboxylic acid polyol has the structure of Formula 2:

[Equation 2]

[HO] xR ₆ -COOH

Wherein x is an integer of 2-5, R ₆ is a branched, cyclic or straight chain having 2-29 carbon atoms; It is a saturated, unsaturated or aromatic hydrocarbon part. Preferably R ₆ has 2-24 carbon atoms and x is 2 or 3 (as in diols or triols). Most preferably, branched or straight chain which x is 2 and R <_6> is C2-C20; It is a saturated, unsaturated or aromatic hydrocarbon structure. In a preferred embodiment, alpha-alpha-dimethylol alkanoic acid, most preferably said alkanoic acid having an alkyl group having 1 to 8 carbon atoms is used as the carboxylated diol. Preferred other diolcarboxylic acids are alpha-alpha-dimethylol acetic acid, alpha-alpha-dimethylolpropionic acid, alpha-alpha-dimethylolbutyric acid, alpha-alpha-diethylolacetic acid, alpha-alpha-diethylolpropionic acid, alpha -Alpha-dipropylolpropionic acid, alpha-alpha-dipropylolbutyric acid and 2, 3-dihydroxypropanoic acid.

Optionally, a polyol may further be included in the reaction mixture. This will increase the molecular weight of the product. The presence of polyols results in a material of formula 1 where k = 1.

In one embodiment of the present invention, it is preferred to use the case where a high concentration of hydroxyl groups is provided (for example by using a carboxylic acid of formula 2 wherein x is 3, 4 or 5 or by adding a polyol). In this embodiment, hydroxyl dicarboxylic acid is added to the reaction mixture. Equation 3 below shows the structure of any suitable hydroxyl carboxylic acid.

[Equation 3]

[HO] yR _7- (COOH) ₂

Wherein y is 1-5 (preferably 1-3) and R ₇ is straight, cyclic or branched; As a saturated, unsaturated or aromatic hydrocarbon moiety, the number of carbon atoms is 1-28, preferably 1-18, most preferably 1-12. When y is 2-5, R ₇ preferably has 2-18 carbon atoms. Preferably the hydroxyl concentration of the total reaction mixture is at least about per gram of the sum of the reactants (diisocyanate, carboxylic polyol, hydroxylalkyl (meth) acrylate, hydroxyl dicarboxylic acid and, if present, polyol) In the case of 0.3 milliequivalents, this discrete should be used. Suitably, such diacids may be used in an amount of about 0.3-about 0.7 milliequivalents per gram of total reactant.

Suitable hydroxy dicarboxylic acids can be selected from the group consisting of maleic acid, tartaric acid, dihydroxytartaric acid, hydroxyadipic acid, dihydroxyadipic acid and trihydroxy adipic acid.

Such dicarboxylic acids can be used to provide thermoset hanging or terminal terminations. Such terminations may provide a reaction site for reaction with other materials in the future. For example, melamine and epoxy are two compounds or moieties that can react with terminal carboxyl groups. Such reactions can further modify or enhance the character of the material. The specific characteristics or quality required will depend on the intended use of the material.

To prepare the carboxylated urethane di (and / or) tri (meth) acrylate coating compositions of the invention, the reaction is carried out in a dry solvent solution which is itself nonreactive to isocyanates. Suitable examples of such solvents include esters such as ethyl acetate and propylene glycol monomethyl ether acetate; Ketones such as methylethyl-ketone, methylisobutyl ketone and N-methylpyrrolidone; Aromatic hydrocarbons such as toluene and xylene; And mixtures of the foregoing.

The reaction to prepare the coating composition of the present invention is carried out with a solution having a solids content of about 20- about 100% by weight, preferably about 35-95% by weight, most preferably about 65-85% by weight. The reaction temperature is generally about 50-95 ° C., preferably about 65-85 ° C. Preferably, a single polymerization is suppressed by addition of free radical polymerization inhibitors such as hydroquinone, m-dinitrobenzene, phenothiazine and the like. Most preferably, it is used in an amount of about 0.005- about 1% by weight based on the weight of their solids.

Preference is also given to using condensation catalysts such as tin or amine catalysts. Such catalysts include di-butyl tin dilaurate, dimethyl tin dineodecanoate, dibutyl tin bisoctylthioglycolate. Triethylamine and triethylene diamine. The reaction is carried out under a dry air blanket for optimum results.

Diisocyanates may be hydrocarbons which are branched, straight or cyclic, saturated, unsaturated or aromatic. Allowable are 4-20 carbon atoms, preferably 6-18 carbon atoms. The diisocyanate may be selected from the group consisting of: xylene diisocyanate; 1-isocyanato-3-isocyanato-methyl-3, 5, 5-trimethyl cyclohexane; 3, 3'-dimethyldiphenylmethane-4, 4'-diisocyanate; 2, 4-tolylene diisocyanate; 2, 6-tolylene diisocyanate; 2, 4, 4-trimethyl hexamethylene diisocyanate; 2, 4, 4-trimethyl hexamethylene diisocyanate; Methylene-bis (4-cyclohexyl isocyanate); Hexamethylene diisocyanate; Meta-tetramethylxylene diisocyanate; Paratetramethylxylene diisocyanate; Methylene-bis-phenyl diisocyanate; 1,5-naphthylene diisocyanate; Metaphenylene diisocyanate and mixtures thereof. Most preferred diisocyanates are the following: 2, 6-tolylene diisocyanate; 2, 4-tolylene-diisocyanate; 1-isocyanate-3-isocyanato-methyl-3, 5, 5-trimethyl cyclohexane; 2, 2, 4-trimethyl hexamethylene-diisocyanate and 2, 4, 4-trimethyl hexamethylene diisocyanate.

If polyols are included, the molecular weight, cure rate and crosslink density will increase. The polyol may have 2 to 28 carbon atoms. It may be acceptable for the hydrocarbon moiety to be branched or straight chain, saturated, unsaturated or aromatic and having 2-5 hydroxyl moieties.

Preferably, the polyol is a diol or triol having 2-16 carbon atoms. Preferred diols can be selected from the group consisting of: ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, octanediol, neopentylglycol, 2-methylpropane-1, 3 diols, cilohexanedimethanol And diethylene glycol Other preferred polyols are glycerol, trimethylolpropane or hexanetriol which can be used.

The hydroxyalkyl dina tri (meth) acrylate (component c) may have an alkyl group having about 2-28 carbon atoms. Alkyl moieties may also be linear, cyclic or branched, saturated or unsaturated. It is preferable that the alkyl group of hydroxyalkyl (meth) acrylate has 2-12 carbon atoms. Some preferred hydroxyalkyl (meth) acrylates may be selected from the group consisting of the following. Hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate and general formula wherein m is 1 or 2

Compounds having:

When the present coating composition is prepared, the concentration of the reactant should be at least about the same as the amount of diisocyanate present in which the total concentration of hydroxyl groups is present. In general, this indicates that the concentration of diol + hydroxyalkyl (meth) acrylate of the polyol + dialkylol carboxylic acid is sufficient to make the ratio of hydroxyl to diisocyanate at least about 0.95: 1, preferably at least 1: 1. Means that. More preferably, the hydroxyl moiety has an excess equivalent. Preferably, the hydroxyl has an excess equivalent in the range of about 1.05: 1- about 0.95: 1, more preferably 1.02: 1- about 1: 1 when associated with the diisocyanate.

Carboxylic acid polyols are an important component of the present coating composition and are preferably present in an amount sufficient to allow the uncured copolymer to melt or expand in aqueous alkali solution. Suitably, the carboxylic acid polyol is present at about 0.3 milliliter equivalents (acid), the minimum amount per gram of total reactant; Preferably an amount of at least 0.5 milliequivalents per gram of total reactant is present.

Polar solubility is further improved when the acid (meq / TR g) is used in the reaction mixture in an amount of at least 0.8 milliequivalents per gram of total reactant.

A preferred range of g of meq acid / TR is g of acid / TR of about 0.8-about 1.6 meq. If a highly viscous product is desired that is very suitable for mixing with other materials, it is most preferred to contain a minimum amount of about 1 meq of acid / TR, more preferably about 1-about 1.6 meq acid / TR. The use of diacids in FIG. 3 can be used to add to the amount of milli equivalents of acid.

Another advantage obtained by the carboxylation of urethane di and tri (meth) acrylates is that UV sensitive compounds can be mixed with hydrophilic resins. Furthermore, by varying the concentration of carboxylation in urethane di and tri (meth) acrylates, the hydrophilicity of this UV sensitive compound can be controlled to an extended extent. This allows the hydrophilic property to be imparted to the particular resin. Thus, when one wants to use a more hydrophobic or less hydrophilic resin, lower concentrations of carboxylation may be used in urethane di and tri (meth) acrylates to increase the compatibility of the selected resins. Conversely, if one wants to use a hydrophilic resin, the carboxyl concentration will be increased so that the resin and urethane di and tri (meth) acrylates can be mixed to a greater concentration. Carboxylic acid polyols are acceptable in the reaction mixture in an amount ranging from about 5 to about 45 weight percent (abbreviated weight of TR), preferably from about 5 to about 25 weight percent of TR, most preferred Preferably in concentrations having carboxylated polyols in an amount of about 12-about 25% by weight of TR.

In addition, when certain polyols are included, from about 2 to about 18%, preferably from about 2 to 15% by weight of TR may be used in the reaction mixture.

For diisocyanates, the acceptable concentration range is about 30 to about 80 weight percent of TR. Preferably about 50-75% by weight.

Hydroxyalkyl (meth) acrylates must be present in the reaction mixture in a minimum amount of about 0.50 meq of acrylate per gram of TR to aid in proper UV sensitivity. A suitable range is about 0.5-about 1.6 meq acrylate / TR g. The acceptable weight percentage ranges from about 5 to about 50 weight percent of TR, preferably used in an amount from about 10 to about 30 weight percent of TR.

The present carboxylated urethane di (and / or) tri (meth) acrylate copolymer coating compositions are allowed to have a weight average molecular weight of about 500 to about 6,500, preferably a weight average molecular weight of about 800 to about 3,000, more Preferably, it may have a weight average molecular weight (measured by gel permeation chromatography and based on standard polystyrene calibration curve) of about 1000 to about 2,500.

In a preferred embodiment, the coating composition is mixed with a binder. The resin used for this purpose should preferably have a glass transition temperature (Tg) of at least about 155 ° C., most preferably hydrophilic. High Tg will improve heat resistance. Various commercially available resins can be used. Suitable mixtures can be made with the present carboxylated urethane di (and / or) tri (meth) acrylates, in particular by advantageously changing the carboxyl concentration. Acceptable resins that can be used for this purpose include styrene / maleic anhydride copolymers, in particular partially esterified with low molecular weight alcohols. Copolymers of styrene / maleic anhydride are commercially available as esterified with a mixture of methyl-butyl allool. Such copolymers are available in a wide range of molecular weights. Acceptably, the molecular weight of this resin-binder is about 25,000- about 300.000; Most preferably in the range of about 60,000 to about 250,000. Copolymers preferably used have a ratio of styrene to maleic anhydride of about 1: 1 to about 2: 1. The preferred (Tg) range for the binder is about 155 ° C to about 200 ° C.

The binder may be used in an amount of from about 85% to about 25%, preferably from about 17% to about 60%, by weight of the total composition. Preferably the carboxylated urethane di (and / or) tri (meth) acrylate coating composition is mixed with a binder such that the glass transition temperature (Tg) of the final product is about 70-about 190 ° C. Preferably, the binder acid number is about 120-about 280 mg KOH per gram of binder. Other polymers having the above molecular weight, Tg and acid number can be used with the present carboxylated urethane di (and / or) tri (meth) acrylate coating compositions as binders. Suitable polymers for use as binders are methyl methacrylate-commethacrylic acid and methyl methacrylate-methylacrylate-methylacrylic acid.

The present carboxylated urethane di (and / or) tri (meth) acrylates may be added to other materials such as the above binders or other additives that may be acceptable, such as crosslinking agents, dyes, solvents, pigments, photoinitiators, heat inhibitors. When used in conjunction with, the concentration of the UV sensitive carboxylated coating component should be within the range of about 10- about 85% by weight of the total combined composition. Preferably from about 15 to about 75 weight percent, most preferred is in the range from about 1 to about 60 weight percent of the combined composition.

Preferred crosslinkers are (meth) acrylate monomers. Crosslinking agents are used to obtain compositions with greater crosslinking densities and to improve resistance to solvents such as methylene chloride. More preferred are polyfunctional (meth) acrylate monomers. Such polyfunctional monomers may be selected from the group consisting of trimethylolpropane tri (meth) acrylate, trimethylpropane ethoxylated tri (meth) acrylate, dipentaerythritol hydroxypenta acrylate and ditrimethylol propane tetra acrylate. have.

Other crosslinkers that may be used may be selected from the group consisting of divinyl ethers, acrylated epoxy, epoxy resins and aminoplast resins. An acrylated epoxy is preferred because it improves overall heat resistance, solvent resistance and overall adhesion.

When the present carboxylated coating composition is used as a solder mask, the composition is coated on a suitable substrate and dried without adhesion. The coated substrate can then be imaged with UV radiation of about 75-105 mJ / sq.cm and then developed with an aqueous alkali solution. The aqueous alkali solution is preferably potassium carbonate or sodium. In general, the photo-formed coated substrate is inspected on this basis.

When the present coating composition is used, it is advantageous if the coating can be easily stripped with an aqueous alkaline stripper and redone, if desired. The amount of alkali needed for stripping or developing solution is very small. 1% by weight of base solution can be used. When the desired quality phase is obtained, this coating can be obtained with post UV curing of 3-5 mJ / sq.cm. Thereafter it is thermally cured (preferably at 150 ° C.) for a sufficient curing time. The composition has excellent resolution, flexibility and adhesion to the metal.

The present invention can be immediately understood by the following examples. However, these embodiments should be understood only as illustrating the present invention, and the invention should not be used as limiting. All parts and percentages are by weight unless otherwise indicated.

Example 1

The following examples illustrate the preparation of photo-forming coating compositions. The following ingredients are placed in a 5-liter isometric bottom flask equipped with a mechanical steerer, thermometer, condenser, gas injector and heating mantle. 236.0 g (about 4 equivalents) 1,6-hexanediol; 268.0 g (about 4 equivalents) of dimethyl is propionic acid; 951.2 g (about 8.2 equivalents) of 2-hydroxyethyl acrylate, 0.23514 g of phenothiazine as free radical inhibitor: 783.8 g of N-methyl-2-pyrrolidone as solvent; And 31.35 g of dibutyl tin dilaurate (T-12) as catalyst. 1,680.0 g (about 16 equivalents) of trimethylhexamethylene diisocyanate are charged to the mixture at 30 minutes price in two equal portions under a dry-air blanket with shaking. An exothermic reaction occurs at each addition. The reaction temperature was cooled down to 85 ° C. by cooling with an ice-water bath, and after the second addition of trimethylhexamethylene diisocyanate, the reaction temperature was kept constant for 10-12 hours until the isocyanate infrared absorption peak indicating the end of the reaction disappeared. Keep at ℃.

Example 2

The photosensitive coating composition prepared in Example 1 is used to make a photoimaging solder mask. Solder masks are prepared by filling the following components in a 500 ml round bottom flask equipped with a steerer, a gas injector, a thermometer and a condenser: 6.5 g of low molecular weight copolymer defoaming agent; 91.25 g N-methyl-2-pyrrolidone as solvent; Add 82.0 g of esterified styrene / maleic anhydride copolymer as binder (the resin used here is the Scripset 550 available from Monsanto). The mixture is agitated and heated to 95 ° C. for 30 minutes to become hazy. A solution is obtained. The temperature is then lowered to 70 ° C. and the following components are added to the mixture: 0.004 g of free radical polymerization inhibitor, phenothiazine; 77.5 g of the UV sensitive coating composition prepared in Example 1; And 9.0 g green pigment. While blanketing the mixture with a stream of dry air, a premixed solution containing the following components is added: 47.8 g of triethylolpropane triacrylate (SR 351) as crosslinker; 6.5 g isopropyl thioxanthone (abbreviated ITX) as a photoinitiator; And 8.4 g of ethyl P-dimethylaminobenzoate (abbreviated EPD) as a sensitizer.

The ingredients are mixed under a dry air blanket at 70 ° C. for 30 minutes and then poured into an amber ego. The solder mask thus produced is used as described in Example 3.

Example 3

The composition prepared in Example 2 was prepared with a 75 mesh monofilament polyester screen and 70 durometer hardness on two 15 "24 cm x 20.32 cm (6" x8 ") copper coated epoxy plates of approximately 2 mils thick. It is applied as a coating using a rubber squeegee having. This wet coating is dried over 1.4 minutes into a 1.4 mil tack free film in a 100 ° C. forced air oven.

After the dried film is cooled to room temperature, it is exposed to 75 mJ / sq.cm. Through a Institute for Interconnecting Packaging electronic circuits (IPC) NO.B-25 negative artwork with a 400 watt mercury medium lamp. The exposed film is then developed by hand in a 1% solution of K ₂ CO ₃ for 45 seconds and then rinsed with fresh water.

Excellent resolution of the IPC B-25 results.

After this development, the plates are cured at 3 J / sq.cm. And thermally baked at 150 ° C. for 1 hour as a post-curing process.

Thereafter, one of the plates was soaked in methylene chloride (abbreviated MeCl ₂ ) for 15 minutes and no decomposition was found on the mask (solvent resistance test).

The other plates were provided in a cross adhesion test according to ASTM D3358-78 Method B and were found to have no adhesion loss. The plate is then painted with resin flux and suspended on the molten solder pot at 260-275 ° C. for 10 seconds to the side with the solder mask below. After performing the solder pot test, immediately rinse with 1,1,1-trichloroethane while the plates are warmed by distillation. After 1 hour, the plates were provided with the same cross contact test and no adhesion loss was found.

Example 4

The urethane diacrylate oligomer is prepared by varying the amount of carboxylation using the apparatus of Example 1 and the general procedure. Sample 4 has no amount of carboxylation and sample 9 contains the highest amount of carboxylation. All specimens are prepared as 80% solids. The formulation used for each individual sample is shown in Table 1 below.

TABLE 1

The following abbreviations are used.

DMPA = dimethylolpropionic acid

2HEA = 2-hydroxyethyl acrylate

TMDI = trimethylhexamethylene diisocyanate

DTN = dimethyl tin dienedecanoate

M-pyrrole = N-methylpyrrolidone

eq. = equivalent

The viscosity of Examples 4-9 is measured at 23.86 ° C. (75 ° F.) using a Brookfield RVT Viscometer, # 6 spindle at 10 RPM (unit CPS).

Sample # 4 5 6 7 8 9

Viscosity 20 400 22 400 41 600 44 800 68 800 86 400

Example 5

Samples 5-9 of carboxylated urethane acrylates are used to make solder masks. This solder mask is then tested for comparison of the properties. This example along with Examples 6 and 7 below is used to compare the properties of masks containing carboxylated urethane acrylates and uncarboxylated urethane acrylates.

The solder masks indicated here as Example D-H are manufactured using the apparatus described in Example 2 and the general process.

The amount of each component is shown in the table below:

TABLE 2

Comparison of Properties of Solder Masks Containing Carboxylation

Solder Mask (Sample Number) D E F G H

Carboxylated Urethane 5 6 7 8 9

Using the solder mask of specimen D-H, the epoxy plate covered with bare copper was coated according to the process of Example 3. The board is then tested and evaluated.

The luminous flux-sample DH was excellent at 75 mJ / cm ² .

Development: The development in 1% aqueous K ₂ CO ₃ solution was excellent for sample DH.

The phenomenon in 1,1,1-trichloroethane in sample D-H was bad.

Adhesion Test Method: ASTM-D 3359-78 Method B

(Scale 5 = no adhesion loss)

(Scale 0 = complete adhesion loss)

Sample Number D E F G H

Adhesion Before Molten Solder 5 4-5 4-5 5 4-5

Adhesion after molten solder is applied 5 5 5 5 5

Example 6

Sample 4 A solder mask composition sample was prepared according to the process of Example 2 using a non-carboxylated material.

The ingredients and amounts of ingredients are as provided in the table below:

TABLE 3

Each of these formulations (A & B) was tested using the process of Example 3 for comparison and used to coat the epoxy plate covered with copper to further illustrate the features. The results are provided below.

phenomenon

1% aqueous, K ₂ CO3 rain-

1, 1, 1, trichloroethane bad-

Property

Methylene chloride resistance was poor in showing the effect of the solvent after only 2 minutes of exposure.

Adhesion Before Molten Solder * 5

Adhesion after Molten Solder * 5

SR351 = trimethylolpropane triacrylate

ITX = isopropyl thioxanthone

EPD = ethyl p-dimethylamino benzoate

* Cross Adhesive-ASTM-D3359-78 Method B

Scale 5 = No Adhesion Loss

Graduation 0 = Complete Adhesion Loss

Example 7

Also for control purposes, the material of Specimen 4 is used to make the photosensitive element, after which the phenomenon is evaluated in different types of solvents. The photosensitive element (sample c) is prepared by mixing the components of Table 3 below at 50 ° C. in a 500 ml round bottom flask equipped with a steerer, a gas injector, a thermometer and a condenser.

The table below shows the amount of each component.

TABLE 4

Solder mask composition containing non-carboxylated urethane diacrylate (sample 4) (sample C)

phenomenon

Excellent 1,1,1 trichloroethane

1% aqueous K ₂ CO ₃ not developed

Abbreviations used above:

Elbasite 2008 = polymethyl methacrylate (M.W. = 79,000)

PMA = propylene glycol monomethyl ether acetate

Irgacure 651 = 2,2-dimethoxy-2-phenylacetophenone

Uncarboxylated urethane diacrylate (Sample 4) has very limited compatibility with styrene / maleic anhydride resin (scriptset 550). A homogeneous mixture of uncarboxylated urethane diacrylate and styrene / maleic anhydride resin was obtained for a relatively short time (less than one month), but only when the ratio of urethane diacrylate to resin was less than one. If the ratio increases, phase separation occurs (sample B).

However, the carboxylated urethane di or tri (meth) acrylates may have varying concentrations of carboxylation such that they are common and compatible with styrene / maleic anhydride resins and other binder resins in all proportions. The result is good shelf life, uniformity and good performance in product properties.

Example 8

Carboxylated urethane triacrylate specimens are prepared using the apparatus and process of Example 1. Specific components for each triacrylate swatch are provided in the table below.

TABLE 5

Abbreviations used in the table above:

Tone 0301 = polycaprolactone tree of molecular weight 300

Ton M-100 = reactive carpolactone acrylate

IPDI = isophorone diisocyanate

= 1-isocyanate-3-isocyanate-methyl-3,5,5-trimethylcyclohexane

Thereafter, the products of specimens 10 and 11 are used to produce the solder masks of specimens I and J, respectively.

The solder mask is manufactured using the apparatus of Example 2 and a general process.

TABLE 6

Developability:

1% by weight Aqueous K ₂ CO ₃ Outstanding

MeCl ₂ resistance 6 minutes. (Excellent) 8 minutes. (Excellent)

(Soak it in the solvent for the indicated time and test it by evaluating the result as good if no effect and bad as solvent effect.)

Cross Adhesive-ASTM-D3359-78 Method

Scale 5 = no loss of adhesion

Graduation 0 = Complete Adhesion Loss

Adhesion Before Molten Solder 5 4

Adhesion after melt soldering 5 3

The plate used for this test is manufactured using specimens I and J according to the process of Example 3.

Claims (17)

Carboxylated urethane dimethacrylate, carboxylated urethane diacrylate, carboxylated urethane triacrylate and carboxylated urethane trimethacrylate; Component (a) which is a diisocyanate having ₆ to 18 carbon atoms, general formula [OH] xR ₆ -COOH (where x is an integer of 2-5, R ₆ is a straight or branched chain having 2 to ₂₉ carbon atoms; saturated, unsaturated Or a carboxylic acid polyol of an aromatic hydrocarbon part) and hydroxyalkyl diacrylates, hydroxyalkyl dimethacrylates, hydroxyalkyl triacrylates and hydrides each having 2 to 28 carbon atoms of alkyl. Component (c) which is a member selected from the group consisting of oxyalkyl trimethacrylates, provided component (a) is present in an amount of from about 30 to about 80 weight percent based on the total amount of the reaction mixture Is in an amount of about 5 to about 45 weight percent based on the total amount of the reaction mixture, the minimum amount being about 0.3 milliliters of acid per gram of the total amount of the reaction mixture, and component (c) is the minimum amount of about acrylate per gram of the total amount of the reaction mixture About 5- based on the total amount of the reaction mixture, which is 0.5 milliequivalents In that it comprises a UV sensitive polymer made by condensation of the reaction mixture is present in an amount of 50% by weight, characterized in, Koh Ting composition that can be formed by a different light. The composition of claim 1 containing a binder and / or a crosslinking agent. The composition of claim 1 wherein the reaction mixture comprises a polyol having 2-28 carbon atoms and 2-5 hydroxyl moieties. The composition of claim 1 wherein the reaction mixture comprises dicarboxylic acids of the general formula: [OH] _y -R _7- (COOH) ₂ Wherein y is an integer from 1-5 and R ₇ is a hydrocarbon moiety having 1-28 carbon atoms. A compound according to claim 1, wherein component (b) is alpha-alpha-dimethylol acetic acid, alpha-alpha-dimethylolpropionic acid, alpha-alpha-dimethylolbutyric acid, alpha-alpha-diethanol acetic acid, alpha-alpha-diethylol Composition selected from propionic acid and alpha-alpha-diethylol butyric acid. The composition of claim 2 wherein the binder is a styrene / maleic anhydride copolymer having a glass transition temperature of about 155 ° C. or higher. The composition of claim 1, wherein the reaction mixture contains about 0.8-1 6 milliequivalents of acid per gram of total amount of the reaction mixture. 5. The composition of claim 4, wherein the reaction mixture contains a polyol having 2-5 hydroxyl moieties and 2-28 carbon atoms. The diisocyanate according to any one of claims 1 to 8, wherein the diisocyanate is 1-isocyanato-3-isocyanato-methyl-3,5,5-trimethylcyclohexane; Xylene diisocyanate; 3,3'-dimethyl diphenylmethane-4,4'-diisocyanate; 2,4-tolylene diisocyanate; 2,6-tolylene diisocyanate; 2,2,4--trimethylhexamethylene diisocyanate; 2,4,4-trimethylhexamethylene diisocyanate; Methylenebis (4-cyclohexyl diisocyzanate); Hexamethylene diisocyanate; 1,5-naphthylene diisocyanate; Metaphenylene diisocyanate; Meta-tetramethylxylene diisocyanate; A composition characterized in that it is selected from the group consisting of paratetramethylxylene diisocyanate and methylenebis phenyl diisocyanate. Component (a) which is diisocyanate of ₆ to 18 carbon atoms, general formula [OH] xR ₆ -COOH, wherein x is an integer of 2-5, R ₆ is straight or branched chain having 2 to ₂₉ carbon atoms; saturated Component (b) which is a carboxylic acid polyol of an unsaturated or aromatic hydrocarbon part) and hydroxyalkyl diacrylate, hydroxyalkyl dimethacrylate, hydroxyalkyl triacrylate, each having 2 to 28 carbon atoms And component (c) which is a member selected from the group consisting of hydroxyalkyl trimethacrylate, provided component (a) is present in an amount of from about 30 to about 80 weight percent based on the total amount of the reaction mixture b) is in an amount of about 5-about 45% by weight based on the total amount of reaction mixture, the minimum amount being about 0.3 milliliters of acid per gram of the total amount of reaction mixture, and component (c) is the minimum amount of acrylic per gram of the total amount of reaction mixture About 5- based on the total amount of reaction mixture, which is about 0.5 milli equivalent With the reaction mixture which is present in an amount of 50% by weight The method of UV sensitive polymer characterized by configured by carrying out the condensation reaction. The compound of claim 10, wherein the diisocyanate is 1-isocyanato-3-isocyanato-methyl-3,5,5-trimethylcyclohexane; 2,4-tolylene diisocyanate; 2,6: tolylene diisocyanate; 2,2,4-trimethylhexamethylene diisocyanate; 2.4,4-trimethylhexamethylene diisocyanate; Methylenebis (4-cyclohexyl diisocyanate); Hexamethylene diisocyanate; 1,5-naphthylene diisocyanate; Methanephenylene diisocyanate; Meta-tetramethylxylene diisocyanate; Xylene diisocyanate; 3,3'-dimethylphenyl-4,4'-diisocyanate, paratetramethylxylene diisocyanate and methylenebisphenyl diisocyanate. The process according to claim 10 or 11, wherein the reaction mixture contains a polyol having 2-5 hydroxyl groups and 2-28 carbon atoms. The process according to claim 10 or 11, wherein the reaction mixture comprises dicarboxylic acids of the general formula: [OH] _y -R _7- (COOH) ₂ Wherein y is an integer from 1-5 and R ₇ is a hydrocarbon moiety having 1-28 carbon atoms. 12. The method of claim 10 or 11, wherein the reaction mixture contains about 0.8-1.6 milliequivalents of acid per gram of the total reaction mixture. 12. The method of claim 10 or 11, wherein the temperature of the reaction mixture is in the range of about 50-95 ° C. The process according to claim 10 or 11, wherein the reaction mixture contains free radical polymerization inhibitors and condensation catalysts. The method of claim 16, wherein the reaction mixture is in a temperature range of about 50-95 ° C. and is under dry air during the reaction.