CN1347929A - Photosensitive resin composition for producing printing board - Google Patents

Abstract

One kind of photosensitive resin and its preparation, application and formed printed circuit board are disclosed. The photosensitive resin includes one kind of polyurethane prepolymer, which is formed through the reaction of one kind of diisocyanate and at least one kind of polyether diol with olefine unsaturation degree equal to or lower than 0.01 meq/g to form one kind of oligomer and the reaction of the oligomer and at least one kind of hydroxyl acrylate; at least one kind of monomer; and at least one kind of photosensitive initiator.

Description

Be used to make the photosensitive resin composition of printing plate

The present invention relates to a kind of photosensitive resin composition, relate to the printing plate and its corresponding multi-functional printing process of making by this composition.

In offset printing (also being referred to as letterpress), printing ink is by being transferred in the substrate by printing plate in the printing ink pond.Thereby the surface of printing plate forms definite shape makes the image that is printed show especially out, identical mode, and cutting rubber impresses so that the image of printing shows especially on rubber surface.Usually, printing plate is to be installed on the cylinder, thereby raising printing plate surface, the cylinder high speed rotating contacts with the printing ink pond, and slightly wetting by printing ink, withdraw from the printing ink pond then and contact, thereby printing ink is formed printing substrate by being transferred on the outstanding surface of printing plate in the substrate with substrate web.

There is competition between offset printing and other mode of printing such as lithography, intaglio printing and letterpress.The Technology Need that is comprised in offset printing industry constantly improves, thereby more effectively competes with other mode of printing.Cause that the field that investigators note is to develop the improvement printing plate that is used for offset printing.

For offset plates very high requirement is arranged.For example, offset plates must have enough snappinesies (mechanical property) being wrapped on the print drum, and should have the severe condition that enough intensity is stood in printing process with tolerance.And printing plate should have lower hardness or softness is beneficial to printing ink transfer printing in printing process.

Offset printing requires printing plate to have the convex surface image, and this image all has chemical resistance for water-based inks or the alcohol radical printing ink that routine is used for offset printing.In addition, also require the physicals of printing plate and printing performance stable, can in printing or storage, not change.

The resin combination of photopolymerization comprises a kind of elastomeric adhesive usually, also is referred to as prepolymer in the present invention, at least a monomer and a kind of light trigger.Be the preparation printing plate, insert the layer of one deck photopolymerization usually between carrier and one or more layers emulsion sheet, described emulsion sheet comprises sliding conciliates membrane removal with the protection photosurface.After image carries out optical radiation, polymerization, but the not dissolution phenomena of the layer of photopolymerization takes place in the exposure area.Handle the unexposed area that to remove photopolymerizable layer and stay the printing convex surface that can be used for carrying out offset printing with suitable photographic developer.

United States Patent (USP) 3,850,770 disclose a kind of resin combination of photopolymerization, and it comprises the polyether urethane of methacrylic acidifying, and it is based on low-molecular-weight polyethylene oxide or poly(propylene oxide).This patent described the use molecular weight up to the dibasic alcohol of 200Da (dalton) to produce the urethane resin of molecular weight up to 2400Da.Because molecular weight is too high, it is believed that to cause hardness too low and expand too highly, be unfavorable.

United States Patent (USP) 4,057,431 disclose a kind of urethane that is prepared by light polymerization by various ethylene oxide/propylene oxide multipolymers.The Shore hardness of its sample is 95 or bigger, and this prints for the most of substrates in offset printing process is too hard.

United States Patent (USP) 4,006,024 and 3,960,572 have described with various (methyl) Acrylic Acid Monomers and the methacrylic acid of light trigger dilution or the oligopolymer of vinylformic acid end.The described urethane oligomer in patent ' 024 and patent ' 572 is by vulcabond such as tolylene diisocyanate (TDI), and various mixture polyester and polyether glycol, as polypropylene glycol adipic acid ester or polyethylene oxide/propylene oxide multipolymer, and composition thereof obtain.The printing plate that forms can be used for comprising the various substrates of surface cardboard, prints on various types of paper bags and the various types of presspaper package.But, the instability when storage of the photopolymer resin described in ' 024 and patent ' 572 in patent, its reason is that the polyether glycol hydrolysis causes wearing out.

In order to remain on high quality and the printing effect clearly in the operating process, wish very much the edge find a kind of method that need not treatment paper fiber and exsiccant ink deposition thing, described paper fiber and dry ink deposition thing can be filled to the reverse side zone of printing plate and to be deposited on the printing plate printing zone.Very fast when dirty in printing process when printing plate, must in operating process, periodically close printing press, with the cleaning printing plate, make throughput descend.A most important character that requires to possess for the printing plate that is used for printing on corrugated cardboard is high rebound resilience or bounce impact elasticity.

As everyone knows, the polyoxyalkylene polyether glycol is to carry out polymeric by base catalysis.For example, polypropylene oxide glycol is by bifunctional initiator, the propoxylation prepared in reaction under base catalysis.In the propoxylation reaction of base catalysis, competitive side reaction is rearranged into vinyl carbinol with propylene oxide, thereby has introduced the material of unsaturated simple function in reactor.Owing to produce the propoxylation reaction of vinyl carbinol and follow-up generation continuously, make the poly(propylene oxide) molecular weight increase, the average functionality of polyol blends reduces, and molecular weight distribution broadens.This rearrangement reaction is stated in following document: " polymerization principle ", G.Odian, John Wiley and Sons, 1981,515 pages of .Degree of unsaturation records according to ASTM method D4671-93: " urethane raw: unsaturation in polyols is measured ", the result shows (meq/g) with the milligramequivalent numerical table of every gram polyethers alkene usually.The general value of the degree of unsaturation in the polyether glycol is 0.02meq/g to 0.05meq/g.

United States Patent (USP) 5,185,420 have described the Polyurethane Thermoplastic Elastomer for preparing based on polyether glycol under double metal cyanide (DMC) catalysis.

United States Patent (USP) 5,364,741 have described the method for the solid photosensitive resin printing plate of the urethane that adopts polyether glycol production to contain chain expansion.The document has been described the A-B-A type ethylene oxide/propylene oxide segmented copolymer of preferred use, and wherein, the A block is a polyethylene oxide, and the B block is a propylene oxide, and the A block accounts for the 10-30wt% of total amount.Unsaturated polyurethanes in the document is by with excessive vulcabond glycol being carried out chain extension, carry out chain extension with alkyl two alkanolamines more subsequently, holding envelope to produce with hydroxy alkyl methacrylate or acrylate at last.

The purpose of this invention is to provide a kind of photosensitive resin, this photosensitive resin can be used for production can not cause the aged printing plate because of the duration of storage hydrolysis.

Another object of the present invention has provided a kind of photosensitive resin, and this photosensitive resin can be used for producing and has high resilience, high tensile and tensile elongation and Shore hardness is 25-60, thereby can carry out the printing plate of excellent printing in various substrates.

Another object of the present invention provides a kind of photosensitive resin, and this photosensitive resin can use aqueous detergent to develop after exposure and produce the letterpress plate, and this resin demonstrates swelling property lower in water-based print ink.

Be surprisingly found out that, for for the corrugated cardboard and paper substrates of the polyurethane prepolymer for preparing by low-unsaturated polyether polyatomic alcohol, the photosensitive resin that is used for printing thereon has the fine combination of unique tensile strength, rebound resilience and soft, and produces excellent printing ink transfer printing in the ripple printing.The invention provides a kind of photosensitive resin composition, it comprises: (i) a kind of polyurethane prepolymer; The (ii) at least a monomer that belongs to acrylate or methacrylic ester; (iii) a kind of Photoepolymerizationinitiater initiater.Described polyurethane prepolymer is to form by (methyl) acrylate reactions that at least a alkene degree of unsaturation is equal to or less than blend, vulcabond and a kind of hydroxyl-functional of the polyether glycol of 0.01meq/g or polyether glycol.

Photosensitive resin composition of the present invention comprises a kind of polyurethane prepolymer, a kind of monomer or monomer mixture and a kind of Photoepolymerizationinitiater initiater with at least one (methyl) acrylate group.Polyurethane prepolymer is the blend by polyether glycol or polyether glycol, molecule with at least two isocyanate groups, preferred vulcabond and have an oh group at least and have the molecule of (methyl) acrylate group at least also is referred to as (methyl) acrylate reactions formation of hydroxyl-functional.Wherein, the feature of described polyether glycol is that the terminal olefin degree of unsaturation that has is more preferably less than 0.007meq/g less than 0.01meq/g.Suitable polyether glycol comprises: Acclaim 3201, Acclaim 3205, Acclaim 4220, Acclaim 2200 and Acclaim 2220, be purchased Square from Arco Chemical of Newtowne, P.A. and PolyL255-37, be purchased Stamford, CT from Olin Corporation of.Other polyether glycol with similar terminal unsaturation degree also suits.Normally according to the D4671-93 of ASTM method, title is that " urethane raw: the mensuration of unsaturation in polyols " measured to degree of unsaturation, and the result represents with the milligramequivalent number (meq/g) of every gram polyethers usually.Correspondingly, has hydroxyl-functional number in its per molecule of polyether glycol of low saturation near 2.0 oh groups.Usually, the hydroxyl-functional number that is used for the present invention's polyether glycol surpasses 1.97.The polyether glycol that degree of unsaturation is higher than 0.01meq/g says on the whole and is not suitable for the present invention, to such an extent as to because the rebound resilience of the printing plate that forms by the liquid light maleate resin that mixes this polyether glycol too low usually they can not clearly print to corrugated cardboard or other kraft paper.

Preferred polyether glycol is the PEP-101 that satisfies the degree of unsaturation of above-mentioned substandard.This PEP-101 can be random copolymers, segmented copolymer or segmented copolymer.More preferably, they are random copolymers or segmented copolymer.First-selected is, they are the ethylene oxide/propylene oxide multipolymer of many blocks, segment in the middle of it comprises, segment comprises the random copolymers of a small amount of oxyethane (for example being lower than 25%) and propylene oxide in the middle of described, also comprise terminal segments, described terminal segments comprises propylene oxide and 25% or the random copolymers of polyepoxyethane more.

Observe, ethylene oxide content is that the PEP-101 of 10-30wt% can be given the rebound resilience of offset plates with excellence, intensity and tear strength.The rebound resilience measured to the printing plate of being made by resin of the present invention (D2632 according to the ASTM method is measured by Bayshore rebound resilience value) is 40-60%.More preferably the Bayshore rebound resilience is greater than 45%.For comprising polyether glycol and degree of unsaturation greater than for the printing plate of 0.01meq/g, its Bayshore rebound resilience value is usually less than 40%.At least 10wt% oxyethane exists the unexposed area that also makes photosensitive resin to be easier to remove by with water-detergent solution the photo polymer plate that exposes being washed.

In order to produce the photopolymer that viscosity number is applicable to the production offset plates, and, have suitable hardness in order to produce, tensile strength, tensile elongation and an elastic printing plate, preferably use molecular-weight average to be about 500 to about 5000 polyether glycol.More preferably the molecular-weight average of polyether glycol is greater than 2000, and first-selected about 2500 to about 4500.

Polyurethane prepolymer of the present invention is preparation like this: at first, make described polyether glycol and the raw material with at least two isocyanate groups, preferred di-isocyanate reaction.The vulcabond that is used to prepare polyurethane prepolymer of the present invention is preferably aromatic diisocyanate, and certainly, aliphatic vulcabond also can use.General aromatic diisocyanate comprises: methylenediphenyl diisocyanates (is a ditan-4,4 '-vulcabond), and p-Xylol vulcabond, Toluene-2,4-diisocyanate, 4-vulcabond, Toluene-2,4-diisocyanate, 6-vulcabond or back two kinds of isomer (promptly 2,4-and 2,6-tolylene diisocyanate) mixture, naphthalene-1,5-vulcabond, benzyl phenyl ether 4,4 '-vulcabond etc.

Aliphatic series and/or alicyclic diisocyanate also can be used as the vulcabond composition.Suitable aliphatic vulcabond comprises that those fat chains have the vulcabond of 2-12 carbon atom, for example, ethylidene diisocyanate, trimethylene diisocyanate, butylidene vulcabond, hexylidene diisocyanate 2,2,4-trimethylammonium methylene diisocyanate etc.

Suitable alicyclic diisocyanate comprises: 1, and 4-vulcabond hexanaphthene, dicyclohexyl methyl hydride-4,4 '-vulcabond (being the dicyclohexyl methylene diisocyanate), isophorone diisocyanate etc.

In order to produce the urethane oligomer of vulcabond end, preferably with excessive vulcabond and polyether glycol reaction.The mol ratio of dibasic alcohol component and vulcabond is preferably about 1.0: 1.08 to 1.0: 1.5, more preferably from about 1.0: 1.12 to 1.0: 1.3.The molecular-weight average of urethane oligomer is preferably about 6,000 to 30,000, and more preferably from about 8,000 to 25,000, first-selected about 12,000 to 20,000.

Preferred diol contacts reactant with reaction between vulcabond in the presence of the catalyzer of effective concentration and realizes that catalyzer is preferably dibutyl tin laurate or other tin alkyl catalyzer, and catalyst concentration is preferably about 10 to about 20ppm.Temperature of reaction should be about 60 ℃, and under this temperature, the reaction times is approximately 1.5 hours.

After polyether glycol or dibasic alcohol and excessive di-isocyanate reaction obtain the urethane oligomer of isocyanic ester-end, make the reaction of this oligopolymer and hydroxy acrylate or hydroxyl-metacrylate with introducing alkene class unsaturated link(age) in oligopolymer, and polyurethane prepolymer is provided.Suitable hydroxy acrylate or hydroxyl-metacrylate include but not limited to: (methyl) vinylformic acid 2-hydroxy propyl ester, polypropylene glycol monomethacrylate, polypropylene glycol mono acrylic ester or acrylated caprolactone oligopolymer.Wherein, in order to produce the necessary soft photopolymer of printing in the corrugated cardboard with irregular surface or other cellulosic acid substrate, preferred polypropylene glycol monomethacrylate and acrylated caprolactone oligopolymer.

Second component of photosensitive resin composition of the present invention is the monomer with at least one acrylic acid groups, also is referred to as reactive monomer or is called monomer simply.Reactive monomer of the present invention can be any conventional available material with one or more photopolymerization functional group.Preferred reactive monomer is single or many acrylic or methacrylics acid compound, comprises their ester.Among the present invention, (methyl) vinylformic acid refers to one or both in methylacrylic acid and the vinylformic acid simultaneously.

Use has two or more alkene class unsaturated groups in monomer compound can increase the hardness of printing plate.Thereby, should control the consumption of this compound, so that printing plate has required hardness.For this reason, preferred reactive monomer is the mixture of single (methyl) acrylate and many (methyl) acrylate.

The example of reactive monomer is the ester of vinylformic acid and/or methylacrylic acid and monohydroxy-alcohol or polyvalent alcohol, include but not limited to: (methyl) butyl acrylate, (methyl) 2-EHA, (methyl) isodecyl acrylate, (methyl) vinylformic acid lauryl hydroxyethyl ester, hexane-1,6-glycol two (methyl) acrylate, 1,1,1-trimethylolpropane tris (methyl) acrylate, two, three and TEG two (methyl) acrylate, tripropylene glycol two (methyl) acrylate, tetramethylolmethane four (methyl) acrylate, propoxylation TriMethylolPropane(TMP) list, two and three (methyl) acrylate, ethoxylated trimethylolpropane three (methyl) acrylate and have (methyl) acrylic acid oligomeric polyhutadiene promptly has the oligomeric polyhutadiene of the alkene double bond of active photopolymerization.

Preferred monomer is lauryl methacrylate(LMA), polypropylene glycol monomethacrylate, trimethylolpropane trimethacrylate and TEG dimethacrylate.

In photosensitive resin composition of the present invention, the proportional part of reactive monomer is by the viscosity decision of the liquid light maleate resin that forms.For the polyurethane prepolymer of given molecular weight, the monomeric amount of mixing in the photosensitive resin is big more, and then the viscosity of the resin of Xing Chenging is low more.The viscosity of photosensitive resin is preferably 10,000cps to 100, and 000cps, preferred 20,000cps to 50,000cps, first-selected about 25,000cps is to about 40,000cps.For given molecular weight polyisoprene urethane prepolymer,, do not need too much experience for realizing that the amount that makes required photosensitive resin have the required unsaturated reactive monomer of given viscosity is that those skilled in the art are easy to determine.

Usually, in the weight of photopolymerizable mixture, the amount of reactive monomer is about 10～35wt%, more preferably from about 15～30wt%.

The third component of photosensitive resin composition of the present invention is a Photoepolymerizationinitiater initiater.The type that is used for Photoepolymerizationinitiater initiater of the present invention do not had particular determination.Thereby, can adopt any routine to be used for the Photoepolymerizationinitiater initiater of photosensitive resin composition.

As being used for Photoepolymerizationinitiater initiater of the present invention; can use in following one or more: acenaphthenequinone; acylphosphine oxide; aminoacetophenone; the benzo anthraquinone; benzoin methyl ether; the bitter almond oil camphor isopropyl ether; the bitter almond oil camphor n-butyl ether; benzophenone; benzyl dimethyl ketal; benzophenone; the benzil dimethyl acetal; benzil 1-methyl 1-ethyl acetal; 2; 2-diethoxy-2-phenyl methyl phenyl ketone; 2-dimethoxy benzoyl diphenyl phosphine oxide; 2; the 2-dimethoxy-2-phenyl methyl phenyl ketone (promptly; Irgacure  651 (Ciba-Geigy)); 4; 4 '-two (dimethylamino) benzophenone; 2-ethyl-anthraquinone/2; 4; 6-trimethylbenzoyl phenyl-phosphonic acid ethyl ester; hydroxy acetophenone; 2-hydroxy-2-methyl Propiophenone; 2-hydroxy-2-methyl-4 '-the isopropyl Propiophenone; the 1-hydroxycyclohexylphenylketone; 4 '-the morpholino phenylbenzyl ketone; 4-morpholino benzophenone; α-phenyl propyl phenyl ketone; 2; 4; 6-trimethylbenzoyl diphenyl phosphine oxide; 4,4 '-two (dimethylamino) benzophenone.

Light trigger can use separately or use with another kind of light trigger or with coinitiator; for example; EAQ and 4,4 '-two (dimethylamino) benzophenone, benzoin methyl ether and triphenylphosphine, benzil dimethyl ketal and benzophenone, diacyl phosphine oxide and tertiary amine or acyl group diaryl phosphine oxide and benzil dimethyl ketal.

The consumption of Photoepolymerizationinitiater initiater can be through reasonable time back of the body exposure and forms the offset plates bottom and form any effective concentration with required image resolving power.The described time is relevant with the type of formation image, and relevant with the thickness of required offset plates.The significant figure amount of Photoepolymerizationinitiater initiater depends on the type of selected initiator.

The concentration range of suggestion light trigger is 0.1-10wt%.When the amount of light trigger was lower than 0.1wt%, then ultra-violet curing concentration can reduce, and the physicals of photo polymer plate diminishes extreme.When the amount of light trigger surpasses 10wt%, any performance is had not a particle of benefit, and the cost of preparation is also undesirable.

For 2,2-dimethoxy-2-phenyl methyl phenyl ketone, the consumption of light trigger is about 0.1% to about 5% in photopolymerizable mixture, preferred about 0.1% to about 1.5%, and more preferably from about 0.15% to about 0.5%.

In order to protect photopolymerizable mixture unlikely, can in mixture, add the antioxidant commonly used of significant quantity because of the oxygen in the atmosphere carries out oxidation and thermooxidizing is decomposed.The example of antioxidant is: hindered phenol, as 2,6-ditertbutylparacresol (BHT), alkylation thiobisphenol and alkylidene bisphenols, as 2,2-methylene-bis-(4-methyl-6-tert butyl phenol) or 2, two (1-hydroxy-4-methyl-6-tert-butyl-phenyl) sulfide of 2-, hydroxybenzyl compounds, as 1,3,5-trimethylammonium-2,4,6-three (3, the 5-di-tert-butyl-4-hydroxyl benzyl) benzene, triaizine compounds is as 2-(4-hydroxyl-3,5-tert.-butylbenzene amino)-4,6-pair-(n-octyl sulfenyl)-1,3,5-triazines, polymeric trimethylammonium quinol, dithiocarbamic acid dibutyl zinc, dilauryl thiopropionate and phosphorous acid ester are as three (nonyl phenyl) phosphorous acid ester.BHT is a preferred anti-oxidants.

Suitable slip additive can add in the photosensitive resin to reduce printing plate surface viscosity, and as United States Patent (USP) 4,716,094 is described, and the document is introduced the present invention as a reference.

Photosensitive resin of the present invention can solidify by carrying out photochemical exposure, wash removing unpolymerized resin with the aqueous solution subsequently, thereby obtain printing offset plates clear and that can not lift up, or it is easy to remove paper scrap and fiber and dried printing ink.This makes offset plates of the present invention can be used to print corrugated cardboard or by paper bag or container that kraft paper is made, need not as commonly known in the art to clean printing plate continually because of exsiccant paper scrap and fiber gather.Certainly, printing plate of the present invention also can be used for other than finding usually on the corrugated cardboard on the fibre plate of paper scrap still less.

Preparing printing plate by photosensitive resin of the present invention can adopt any routine to be used for the employed method of other photosensitive resin.That is to say that photosensitive resin can be set at the substrate backing layer and paste the one deck of the uniform thickness between the tectum of plate, described cover layer face is facing to plate and this layer is carried on the back with optical radiation exposes and image exposure, subsequently printing plate is developed.

The substrate backing layer also is referred to as carrier, and it can be any and is conventionally used for the flexible materials that the preparation offset plates has photosensitive composition.Suitable base material comprises polymeric membrane, those as forming by adduct polymerization thing and linear condensation polymer, transparent film and fabric.Preferred substrate is a polyester film; Preferred especially polyethylene terephthalate.The thickness of substrate is generally 2 to 10 mils (0.0051 to 0.025cm), and preferred thickness is 4 to 7 mils (0.010 to 0.018cm).

The thickness of the printing plate that prints on corrugated cardboard is generally about 0.067 to about 0.250 inch.The protruding layer thickness of this printing plate is generally about 0.025 to about 0.125 inch, and it depends on the thickness of printing plate.Having as mentioned above, the photosensitive resin of viscosity has reduced contingent flowing in the process that forms described thick layer, this flow will cause the photosensitive resin layer thickness not wish the variation in thickness that occurs, but this resin still makes and is easy to handle in process of production and shift photosensitive resin.The offset plates that is used for printing in other substrate except that corrugated cardboard can require to be different from above-mentioned plate thickness.

The example of suitable optical emitter is sunlight and commercial UV fluorescent tube, middle pressure, high pressure and low pressure mercury lamp, and the ultraphotic fluorescent tube, xenon flash lamp is doped with the lamp and the carbon arc lamp of metal iodide.Being preferred for photo polymer plate of the present invention adopts ultraviolet ray to be cured, ultraviolet wavelength is 150-500nm, 300-400nm particularly, it is normally produced by low pressure mercury lamp, high voltage mercury lamp, carbon arc lamp, Ultraluminescence lamp, chemical lamp, xenon lamp or zirconium lamp.

Be actually used in the device that photo polymer plate is developed and divide several types.A kind ofly by pressurized air unexposed portion is blown out to form convex surface.Another kind is by pressurization plate to be sprayed to wash away solution to form convex surface.Thereby also having a kind of is to make unexposed being partially dissolved in form convex surface in the solution by the plane of being fixed on flat surfaces or the cylinder with the brush brush.Preferably,, photo polymer plate is developed with photographic developer (being also referred to as erosion solution), unexposed no image section is removed by after solidifying exposing with above-mentioned light source.This process has formed the convex surface image on photo polymer plate.The unexposed part of removing by erosion solution still is present in the erosion solution of erosion in bathing with emulsion or form of suspension.

The preferred aqueous developer of using.The alternative that is preferably photographic developer contains the water of basic cpd (as sodium hydroxide and yellow soda ash), tensio-active agent and water-miscible organic solvent.Adding tensio-active agent can make photopolymer be easy to be scattered in the water and remain in the water to disperse.Preferred surfactants is sodium alkyl naphthalene sulfonate and alkylbenzene yellow soda ash.Other example of tensio-active agent comprises: the anion surfactant that contains carboxylate salt, vitriol-ester, sulfonate or phosphoric acid salt-ester; Nonionogenic tenside such as polyethyleneglycol derivative, polyol derivative and sorbitan derivatives; Contain primary, the cats product of the second month in a season or tertiary ammonium salt or quaternary ammonium salt; And the amphoterics that contains amino acid hydrophilic radical or trimethyl-glycine hydrophilic radical.Erosion solution should be at 25-50 ℃, and preferred 30-40 ℃ is used down.The concentration of tensio-active agent in water is also unrestricted, but is generally about 0.5% to about 4%.Develop by carrying out jet cleaning though plate is the most frequent, also can adopt those other technology as mentioned above that comprises with reagent solution.

After the development, the photopolymer offset plates keeps a kind of surface viscosity of degree usually at least, particularly on " shoulder " in convex surface and other no image area territory.Excessive surface viscosity is undesirable in the printing convex surface.Have several method can reduce this surface viscosity, they all can be used in the printing plate of the present invention.For example, known in the prior art, carry out short-wave radiation, as United States Patent (USP) 4,202,696 described (document is introduced the present invention as a reference), this short-wave radiation can make the plate after fixing with the short wavelength light radiation by after being exposed to some carbonyl compound and comprising benzophenone, thereby reduces surface viscosity.Similarly, can in photosensitive resin, add and increase sliding additive, as United States Patent (USP) 4,716,094 described (document is introduced the present invention as a reference), thus reduce the viscosity of established printing plate.

Under 20 ℃, the Shore hardness of printing plate of the present invention is 25-60, more preferably 30-45.

Printing plate of the present invention also should have 45% or bigger bounce impact elasticity (measuring as previously mentioned) in the time of 23 ℃.If bounce impact elasticity exceeds this scope, then printing plate is removed the ability that adheres to lip-deep paper scrap of plate etc. and will be reduced.Therefore, will have to end printing operation with the cleaning printing plate.

Following embodiment only is used for illustration purpose.In each embodiment, printing plate hardness is to adopt Shore hardness tester (available from Shore Instrument and ManufacturingCo.), measures according to ASTM method D-2240.The printing plate rebound resilience is provided by the rebound resilience value according to the described process measurement of ASTM method D2632, and wherein, thickness of sample is 0.250 inch, adopts the Bayshore reisilometer to measure down in 23 ℃.Adopt the Bayshore reisilometer available from Shore Instrument and Manufacturing or available from PrecisionScientific Co..

Each of photopolymerisable compositions among the following embodiment all forms a kind of photopolymer printing plate according to following process.Adopt Merigraph  type 3048 exposure apparatuss (available from MacDermid, Incorporatcd, Wilmington, DE.), the photosensitive resin composition thickness that forms one deck between the polyester backing layer of viscosity coating and polypropylene screen tectum is 0.125 " layer, this layer is separated photosensitive resin and plate.Photopolymer carries out dorsal part exposure 2: 30, subsequently egative film is carried out imaging exposure 6: 00.After exposure, remove tectum, again with a kind of erosion washing composition W6410L that contains 2wt%Mergraph  (available from MacDermid, Incorporatcd, Wilmington, DE.) and the aqueous solution of 2wt% tripoly phosphate sodium STPP 35-40 ℃ of following jet cleaning 10 minutes to obtain convex surface.Then, printing plate is immersed in the acidic sulfurous acid sodium water solution, and be 8 molal weights/cm by minimum strength ²Optical radiation carry out after fixing so that the convex part completely solidified of printing plate.Then, printing plate is following dry 30 minutes at 40 ℃.And then, under sterilization light, plate is carried out dry post-exposure step 10 minute.The Shore hardness of each plate and Bayshore rebound resilience are measured according to said process.Photosensitive resin composition is cured to measure tensile strength and tensile elongation, is photosensitive resin composition is pressed in 0.004 thickness of " between the polyester chips of uncoated and polypropylene screen 0.040 ".Photopolymer is carried out rear side exposure 30 seconds, carry out front side exposure 400 seconds subsequently.Prune polyester and polypropylene screen, sample carries out cross cutting to carry out stretching experiment according to ASTM method D-412.Following embodiment has reported various photopolymerizable compositions and experimental result.

Embodiment 1

Acclaim3205 (poly(propylene oxide)/oxyethane glycol with 1349g (0.429mol), molal weight=3000, degree of unsaturation is 0.003meq/g, derives from Arco ChemicalCo.), the tolylene diisocyanate (TDI) of 90g (0.515mo1) and dibutyl tin laurate (DBTDL) catalyzer of 0.10g add in the 2L resin kettle that has nitrogen purge device, air agitator and thermopair.After initial thermopositive reaction, with reaction mixture remain on 60 ℃ following 2 hours, reach 0.40wt% until isocyanate concentration, carry out titration with di-n-butyl amine and record.In reaction mixture, add the polypropylene glycol monomethacrylate (molal weight 380g/mol) of 160.0g (0.421mol), the BHT of 1.6g and the DBTDL of 0.06g again, with content remain on 60 ℃ following 2 hours, show until titration not have isocyanic ester.

Composition A

In the urethane prepolymer of the above-mentioned formation of 70.8g, add the polypropylene glycol monomethacrylate of 14.5g, the lauryl methacrylate(LMA) of 7.3g, the trimethylolpropane trimethacrylate of 1.4g, the TEG dimethacrylate of 1.2g, the N of 1.5g, the BHT of Irgacure 651, the 0.1g of the methyldiethanolamine of N-diethyllaminoethyl methacrylic ester, 0.3g, the tetradecanoic acid of 2g, 0.3g and the benzophenone of 0.6g.The mixture that forms was stirred 2 hours, obtain a kind of photosensitive resin composition.This resin is made photopolymer printed circuit board (PCB) and aforesaid experiment slice, find that its Bayshore rebound resilience is 49%, tensile strength is 870psi, elongation be 327% and Shore hardness be 32.With this experiment slice under 50 ℃ and 90% relative humidity in storeroom storage do not observe changes of properties after 28 days.

Composition B

In the urethane prepolymer of the above-mentioned formation of 70.0g, add the polypropylene glycol monomethacrylate of 14.5g, the lauryl methacrylate(LMA) of 9.5g, the trimethylolpropane trimethacrylate of 1.0g, the TEG dimethacrylate of 1.0g, the N of 1.5g, the tetradecanoic acid of N-diethyllaminoethyl methacrylic ester, 2g, the Irgacure 651 of 0.4g and the BHT of 0.1g.The mixture that forms was stirred 2 hours, obtain a kind of photosensitive resin composition.This resin is made photopolymer printed circuit board (PCB) and aforesaid experiment slice, find that its Bayshore rebound resilience is 45%, tensile strength is 963psi, elongation be 358% and Shore hardness be 34.

Prepared printing plate is used for printing 33,000 corrugated cardboards.Printing ink transfer printing, coverage and color density are all fine, are easy to remove additional onboard and sedimentary paper scrap or fiber.In the entire operation process, need not to stop printing and come the cleaner plate face.

Embodiment 2

The Acclaim 2220 (polyoxypropylene diols of oxyethane end envelope with 1305g (0.327mol), molal weight=2200, degree of unsaturation is 0.005meq/g, derives from ArcoChemical Co.), the TDI of 69g (0.395mol) and dibutyl tin laurate (DBTDL) catalyzer of 0.10g add in the 2L resin kettle that has nitrogen purge device, air agitator and thermopair.After initial thermopositive reaction, with reaction mixture remain on 60 ℃ following 2 hours, reach 0.40wt% until isocyanate concentration, carry out titration with di-n-butyl amine and record.In reaction mixture, add the polypropylene glycol monomethacrylate (molal weight 380g/mol) of 224.0g (0.421mol), the BHT of 1.6g and the DBTDL of 0.06g again, with content remain on 60 ℃ following 2 hours, show until titration not have isocyanic ester.

In the urethane prepolymer of the above-mentioned formation of 70.7g, add the polypropylene glycol monomethacrylate of 14.5g, the lauryl methacrylate(LMA) of 7.3g, the trimethylolpropane trimethacrylate of 1.5g, the TEG dimethacrylate of 1.2g, the N of 1.5g, the BHT of Irgacure 651, the 0.1g of the methyldiethanolamine of N-diethyllaminoethyl methacrylic ester, 0.3g, the tetradecanoic acid of 2g, 0.3g and the benzophenone of 0.6g.The mixture that forms was stirred 2 hours, obtain a kind of photosensitive resin composition.As mentioned above, this resin is made the photopolymer printed circuit board (PCB), or experiment slice, find that its Bayshore rebound resilience is 46%, tensile strength is 740psi, elongation be 334% and Shore hardness be 26.

Prepared printing plate is used for printing 33,000 corrugated cardboards.Printing ink transfer printing, coverage and color density are all fine, are easy to remove additional onboard and sedimentary paper scrap or fiber.In the entire operation process, need not to stop printing and come the cleaner plate face.

Comparative example

The Poly G55-63 (polyoxypropylene diols of oxyethane end envelope with 634g (0.316mol), molal weight=2000, degree of unsaturation is 0.023meq/g, derives from OlinCorp.), the TDI of 60.5g (0.347mol) and the DBTDL of 0.03g add in the 2L resin kettle that has nitrogen purge device, air agitator and thermopair.After initial thermopositive reaction, with reaction mixture remain on 60 ℃ following 2 hours, reach 0.540wt% until isocyanate concentration, carry out titration with di-n-butyl amine and record.In reaction mixture, add the polypropylene glycol monomethacrylate (molal weight 380g/mol) of 106.0g (0.0279mol), the BHT of 1.6g and the DBTDL of 0.06g again, with content remain on 60 ℃ following 2 hours, show until titration not have isocyanic ester.

In the urethane prepolymer of the above-mentioned formation of 69.6g, add the polypropylene glycol monomethacrylate of 15g, the lauryl methacrylate(LMA) of 8g, the trimethylolpropane trimethacrylate of 1.0g, the TEG dimethacrylate of 1.6g, the N of 1.5g, the tetradecanoic acid of N-diethyllaminoethyl methacrylic ester, 2.3g, the BHT of Irgacure 651, the 0.1g of 0.3g and the benzophenone of 0.6g.The mixture that forms was stirred 2 hours, obtain a kind of photosensitive resin composition.As mentioned above, this resin is made the photopolymer printed circuit board (PCB), or experiment slice, find that its Bayshore rebound resilience is 34%, tensile strength is 720psi, elongation be 349% and Shore hardness be 28.

Prepared printing plate is used for printing 33,000 corrugated cardboards.Printing ink transfer printing, coverage and color density are all poor than embodiment 1 and 2.In the entire operation process, must stop several times to clean dried printing ink, paper scrap and fiber from printing plate.

Claims (20)

1. photopolymer compositions, it comprises:

A) a kind of polyurethane prepolymer, it is by at least a vulcabond and the reaction of at least a polyether glycol, the alkene degree of unsaturation of described polyether glycol is equal to or less than 0.01meq/g, form a kind of oligopolymer, make described oligopolymer form polyurethane prepolymer with (methyl) acrylate reactions of at least a hydroxyl-functional again;

B) at least a monomer; With

C) at least a photoinitiator.

2. photopolymer compositions according to claim 1, wherein, the alkene degree of unsaturation of at least a polyether glycol is equal to or less than 0.007meq/g.

3. photopolymer compositions according to claim 1, wherein, the polyether glycol that at least a alkene degree of unsaturation is equal to or less than 0.01meq/g is a kind of multipolymer, and it is selected from random PEP-101, epoxy ethane-epoxy propane segmented copolymer and composition thereof.

4. photopolymer compositions according to claim 1, wherein, the polyether glycol that at least a alkene degree of unsaturation is equal to or less than 0.01meq/g is many block ethylene oxide-epoxy propane copolymers, it has medium many blocks, comprise random PEP-101, wherein oxyethane is greater than 25%.

5. photopolymer compositions according to claim 3, wherein, the alkene degree of unsaturation of at least a polyether glycol is equal to or less than 0.007meq/g.

6. photopolymer compositions according to claim 4, wherein, the alkene degree of unsaturation of at least a polyether glycol is equal to or less than 0.007meq/g.

7. printed circuit board (PCB), it comprises the photoresponse product of photopolymer compositions, and described photopolymer compositions comprises:

A) a kind of polyurethane prepolymer, it is by at least a vulcabond and the reaction of at least a polyether glycol, the alkene degree of unsaturation of described polyether glycol is equal to or less than 0.01meq/g, form a kind of oligopolymer, make described oligopolymer form polyurethane prepolymer with (methyl) acrylate reactions of at least a hydroxyl-functional again;

B) at least a monomer; With

C) at least a photoinitiator.

8. printed circuit board (PCB) according to claim 7, wherein, the alkene degree of unsaturation of at least a polyether glycol is equal to or less than 0.007meq/g.

9. printed circuit board (PCB) according to claim 7, wherein, the polyether glycol that at least a alkene degree of unsaturation is equal to or less than 0.01meq/g is a kind of multipolymer, and it is selected from random PEP-101, epoxy ethane-epoxy propane segmented copolymer and composition thereof.

10. printed circuit board (PCB) according to claim 7, wherein, at least a alkene degree of unsaturation is equal to or less than the polyether glycol of 0.01meq/g for being many block ethylene oxide-epoxy propane copolymers, it has medium many blocks, comprise random PEP-101, wherein oxyethane is greater than 25%.

11. printed circuit board (PCB) according to claim 7, wherein, the Bayshore rebound resilience of printed circuit board (PCB) is greater than 40%.

12. printed circuit board (PCB) according to claim 9, wherein, the alkene degree of unsaturation of at least a polyether glycol is equal to or less than 0.007meq/g.

13. printed circuit board (PCB) according to claim 10, wherein, the alkene degree of unsaturation of at least a polyether glycol is equal to or less than 0.007meq/g.

14. a method of making printed circuit board (PCB), described method comprises:

A) make photosensitive composition carry out actinic radiation in the mode that becomes image, wherein, described photopolymer compositions comprises:

(i) a kind of polyurethane prepolymer, it is preparation like this: make the reaction of at least a vulcabond and at least a polyether glycol, the alkene degree of unsaturation of described polyether glycol is equal to or less than 0.01meq/g, form a kind of oligopolymer, make described oligopolymer form polyurethane prepolymer with (methyl) acrylate reactions of at least a hydroxyl-functional again

(ii) at least a monomer and

(iii) at least a photoinitiator forms polymeric photopolymer and unsubstituted photopolymer; With

B) make unsubstituted photopolymer video picture.

15. method according to claim 14, wherein, the alkene degree of unsaturation of at least a polyether glycol is equal to or less than 0.007meq/g.

16. method according to claim 14, wherein, the polyether glycol that at least a alkene degree of unsaturation is equal to or less than 0.01meq/g is a kind of multipolymer, and it is selected from random PEP-101, epoxy ethane-epoxy propane segmented copolymer and composition thereof.

17. method according to claim 14, wherein, at least a alkene degree of unsaturation is equal to or less than the polyether glycol of 0.01meq/g for being many block ethylene oxide-epoxy propane copolymers, it has medium many blocks, comprise random PEP-101, wherein oxyethane is greater than 25%.

18. method according to claim 16, wherein, the alkene degree of unsaturation of at least a polyether glycol is equal to or less than 0.007meq/g.

19. method according to claim 17, wherein, the alkene degree of unsaturation of at least a polyether glycol is equal to or less than 0.007meq/g.

20. printed circuit board (PCB) according to claim 18, wherein, the Bayshore rebound resilience of printed circuit board (PCB) is greater than 40%.