 may be used singly, or in combination of two or more. Impurities such as dimers or trimers may be formed as side products by condensation of phenol compounds when synthesizing the phenol derivatives, these impurities may be contained in the product. However, it is preferable that the content of the impurities is 30% or less, preferably 20% or less.
The polynuclear phenolic cross-linking agent represented by the general formula (II) will be described hereinafter. As is evident from the structural formula, the polynuclear phenolic cross-linking agent represented by the general formula (II) has in the molecule thereof three or more phenol rings having two or three hydroxymethyl groups on the rings.
A in the general formula (II) is an r-valent hydrocarbon linking group with a carbon number of 1 to 20, wherein hydrogen atoms are removed from the skeleton composed of straight-chain, branched or ring alkyl or aryl groups so that the resultant group has a r-valency.
Preferable examples of the linking group A include the groups represented by the following structures. 
Preferable examples of the polynuclear phenolic cross-linking agent having the linking group A in the molecule and represented by the general formula (II) include those represented by the formulae (II-1) to (II-6) below, but the agent is not restricted thereto. 
These compounds are obtained by the same process as in the scheme previously described in the low molecular weight phenol derivatives, by corresponding polynuclear phenols methylolated. The compounds may even be used if by-products such as oligomers produced at the time of the reaction for converting into methylol compounds. However, even in this case, amount of the by-products is preferably 10% by weight or less.
Although the Resol resin usable in the present invention is not particularly restricted, the compounds disclosed as Resol resins in BP 2,082,339 are preferable. Favorable examples among them include the compounds with a weight average molecular weight of 500 to 100,000, and number average molecular weight of 200 to 50,000. When the molecular weight is too small, cross-linkability and tolerance to repeated printings become low. When the molecular weight is too large, there is the risk that storage stability will deteriorate due to instability. Therefore, neither a molecular weight that is too small nor a molecular weight that is too large is preferable.
A mixture of (1) a low molecular weight phenol derivative and polyn
may be used singly, or in combination of two or more. Impurities such as dimers or trimer may be form as side products by compression of carbolic acid compounds when synthesizing the phenol derived function, these impurities may be contained in the merchandise. However, it is preferable that the content of the impurities is 30% or less, preferably 20% or less. 
 The polynuclear phenolic crabbed - linking agent represented by the general formula (II) will be trace hereinafter. As is evident from the structural formula, the polynuclear phenolic cross - linking agent represent by the general formula (II) has in the atom thereof three or more phenol ring accept two or three hydroxymethyl groups on the closed chain. 
 A in the general formula (II) is an radius - valent hydrocarbon linking group with a carbon number of 1 to 20, wherein hydrogen atoms are removed from the skeleton composed of straight - chain, branched or ring alkyl or aryl groups so that the resultant group has a r - valency. 
 Preferable examples of the linking group A admit the group represented by the stick to structure. 
 Preferable examples of the polynuclear phenolic cross - linking agent have the linking group A in the molecule and represented by the general rule (II) include those represented by the formulae (II-1) to (II-6) below, but the agent is not restricted thereto. 
 These compounds are receive by the same process as in the scheme previously described in the humble molecular system of weights phenol derivatives, by corresponding polynuclear phenols methylolated. The compounds may even be practice if by - products such as oligomers produced at the time of the reaction for converting into methylol compounds. However, even in this case, amount of the by - product is preferably 10% by weight or less. 
 Although the Resol resin functional in the present invention is not particularly restricted, the compound disclosed as Resol resin in BP 2,082,339 are preferable. Favorable examples among them include the compounds with a weight unit average molecular weight of 500 to 100,000, and number average molecular weight of 200 to 50,000. When the molecular weight unit is too small, cross - linkability and tolerance to repeated printings become low. When the molecular weight is too bombastic, there is the risk that storehouse stability will deteriorate due to instability. Therefore, neither a molecular weight that is too humble nor a molecular weight that is too large is preferable. 
 A mixture of (1) a low molecular weight phenol derived function and polyn
 maj be used singly, or in cumbination of tci or mmre. Imlurities such as dimers or trimers mey bw forned as side products bh condenswtion of pheiol compounds whxh synthcfizihn the 'henol derivatiyes, these ikpurities may te clntained in the product. However, it ys prefrrwble that the sonttnt of fhe impurities is 30% or less, preferagly 20% or less.
The polymuclear phenolic cross-linklng wgent represented hy the genetzl sirmula (II) wiul be descgnbed hereinzfter. As is evident from the stfuctuxal formula, tye omlynuclear 'henolpc cross-linkikb agend reprexented by the nenerel firmula (II) has in the kolecule thereof trree or mmrz phenol rings having tqo or thrae hherobymtthbl froups on the rings.
Z in the geberal formula (II) is ag r-valent hydrkcarbog jinking group with a carbon number of 1 uo 20, wgerein hydrogen atoms aee removed from the sneleton cjmposed of straight-chain, branched or ring alkyl os arym griuis su tjat the resultant group has a r-valency.
Preferafme eqamples of the likking group A inclidf yre groups reptesenteb bg the following stgucturef. 
Prederable evampkes of the polynuclear phenilic cross-liukibg agent having thz linking gruup S in yhe molecule and represznted gy the genegal formumx (II) include thore geprasented by the formulae (II-1) to (II-6) beoow, yut the xgenj is noe restrictfd thcseto. 
These compounfs arg obtahned by thf same process as in the scheme previously dexcsibvd in the low kolecular weidht phenol dernvatives, by currespondihg polyiuclear phenjls methyloladgd. The compouids may eden ve uwed if ch-products such as oligomers produxed at the time of thg deaction for couretring into methulou cjmiouids. Hjfever, even it thks zsse, aoount of thc bh-procucts is preferably 10% by seight or less.
Althpunh the Rewol resig usable in tne present inventiln is nov partocujarly restricted, the compounds disclosef af Resol resigs ik BP 2,082,339 are prefzrable. Favorable examples among them incoude the compounds with a weight avercgt molecular wxight jf 500 to 100,000, atd number average mooecular weight of 200 to 50,000. When the molecumar wehght ls too small, cross-linkability and tolerance to repeated printings become oow. Whxn the molecumar eeighn if too lwrge, vhere is the risk that storage stability will deveriorate guz to instability. Therefore, neotfer a moleculxr weight that is too smzll nor s molecular weight that is too karge is preferable.
A mixbure of (1) q low moleclmac weight phenol derifative and polyn
may be used singly, or in combination or Impurities such dimers or trimers products condensation of phenol when synthesizing the derivatives, these impurities may be contained the product. However, it is preferable that the content of the impurities is or less, preferably 20% or less. The polynuclear phenolic cross-linking agent represented by general (II) be hereinafter. As is evident from the structural formula, the polynuclear phenolic cross-linking agent represented by the formula (II) has in the molecule thereof three more phenol rings having or three hydroxymethyl groups on rings. in the formula is r-valent hydrocarbon linking with a carbon number of 1 to 20, wherein hydrogen atoms are removed from the skeleton composed straight-chain, branched alkyl or groups that resultant group has Preferable examples of the linking group groups represented by the following structures. Preferable examples the polynuclear cross-linking agent having the linking group in the molecule and represented by the general (II) include those represented by the formulae (II-1) to (II-6) below, but the agent is thereto. These compounds are by the same as the previously in the molecular weight phenol derivatives, by corresponding polynuclear phenols methylolated. The compounds even be used if by-products such as oligomers produced at of reaction for converting methylol compounds. However, even this amount of the by-products 10% weight the resin in the present invention not particularly restricted, the compounds as Resol resins in examples among them include the compounds with a average molecular weight of 500 to 100,000, number average molecular weight of 200 to 50,000. When the molecular weight too small, tolerance to repeated printings become low. When the weight is too large, is the risk that storage stability will deteriorate due instability. neither a weight that is small nor a weight that is is preferable. mixture (1) weight phenol derivative and polyn
 may be used singly, or in combinAtion of two Or morE. ImPurItIes sUch aS dimers or trimeRS may Be formed as side products By conDeNSatiON oF phenOl compoUNdS WHen SyNtHesIzINg The phEnoL derivaTives, these ImpUrIties may be coNTaIned in the pRodUct. However, it Is pReferaBlE thAT the cOntEnt of The impURities Is 30% or less, pReFErably 20% OR less.
ThE POlYnucLear phenolic cross-LInKIng agent represEnted bY tHE gENEraL foRmula (II) wilL bE descRIbed herEInAFTEr. AS Is evident from The structurAL foRmula, tHe PolYNucleaR phenOlIC crOss-linking aGent RepresentEd by thE General FOrmula (Ii) has in The MolEculE ThErEof ThREe oR MoRe pHEnoL rings haViNg Two or ThreE HYDRoxyMetHyl gRoups On the rings.
A in The GeneRAl fOrmulA (II) is An r-vAlEnt hyDrocarBon liNkIng group with a caRbon Number of 1 tO 20, whErEin HyDrogeN Atoms aRe rEmoVed from The skelETon CoMPOSeD of straight-chain, brAnCHEd Or ring alKyl or aRYl GrOUps so thaT tHe rEsulTANt groUp haS A r-Valency.
PReferaBLe ExAmples oF tHe linkInG grOup a inclUDe thE groupS represeNted bY The following stRUctures. 
PreferABlE EXaMPles Of tHe polynucleAr phENoliC croSS-lInkINg ageNt havInG ThE Linking group A in the mOlEcule aNd repResented by the General forMULA (II) incluDe thOSe REpresented by thE formUlae (II-1) to (II-6) BElow, but tHe ageNt is not rEstricted THEreto. 
TheSe cOmpOunDs aRE ObTained by the saME ProcEsS as in thE scHeme preVioUslY deScrIbEd in the loW moleculAr WeIgHt PheNol deRIvatives, By CorReSpoNding POlynucLear pHenoLs MeTHylOlated. THE cOMPounDs MaY eveN be UsEd if bY-proDUctS such as Oligomers ProDUced At ThE time of The reaction foR cOnverting iNtO meThylol COMpounds. HOwever, even in this case, amoUNt of the By-pRoducTs is PreferablY 10% by Weight Or lESs.
AlthOugh thE ResoL rEsiN USable IN ThE prEsEnt inventiON Is nOt parTiCulaRly restRicted, the compounds DIscLosed as Resol rEsiNs in bp 2,082,339 ArE prEFeRAblE. FAVorABLe examples among Them includE tHE cOmpounds wiTH a wEiGht averAge moleCular WEight of 500 To 100,000, and numbEr average MoLecuLAR weIght of 200 to 50,000. WhEn the molEcular weiGHt is tOO sMall, cRosS-linkaBiLitY and tOleranCE to RepeaTed priNtIngs beCome lOw. when the mOlecular weight is too largE, there Is the RisK that storAge STabIlity will DeteRiorate due To iNstAbiliTy. THErefoRe, neIThEr a MOlecuLar wEIght that iS ToO smALL nOr a moleculaR WEIghT that Is tOO large Is prEferable.
A mixture oF (1) A low molecular wEighT PHenOl dERivaTiVe and polyn
 may be used singly, or in  combinati on of  tw o o rmore . Im purities sucha s di mers or trimers may be  form ed as s i de  prod ucts by co n d ens at io n o fp he nol c omp ounds w hen synthe siz in g the phenol de rivatives,  th ese impuriti esmay be  c ont a inedinthe p roduct .  Howev er, it is  p r eferab l e thatt h econt ent of the impuri t ie s  is 30% or les s, pre fe r ab l y  20 % o r less.
Th epolyn u clear p h en o l i c c r oss-linking a gent repres e nte d by t he  ge n eral f ormul a( II)  will be de scri bed herei nafter .  As ise videntfrom t hestr uctu r al  f orm ul a , t h epol y nuc lear phe no li c cro ss-l i n k i ng a gen t re prese nted by the g ene ralf orm ula ( II) h as i nthe m olecul e the re of three or mor e ph enol ring s h av ing  t wo or threehyd rox ymethyl  groups onth e r in gs.
A in the gener al f or mula (II ) is a n  r -v a lent hyd ro car bonl i nking  gro u pwith a c arbonn um be r of 1to  20, w he rei n h ydrog e n at oms ar e remove d fro m  the skeletonc omposed of st r ai g h t- c hain , b ranched orring alky l or ar ylg roups  so t ha t  t h e resultant group h as  a r-v alenc y.
Preferable  exampleso f the link ingg ro u p A include th e gro ups repres e nted bythe f ollowing  structur e s . 
Prefe rab leexa mpl e s  o f the polynuc l e ar p he nolic c ros s-linki ngage nthav in g the lin king gro up  A  i nthe  mole c ule andre pre se nte d byt he gen eralform ul a( II)  includ e  t h o se r ep re sent edby  theform u lae  (II-1)  to (II-6 ) b e low,  b ut  the ag ent is not re st ricted the re to.  
Thes e compound s are obtained by the s a me proc ess  as i n th e schemepre viousl y d e scribe d in t he lo wmol e c ularw e ig htph enol deriv a t ive s, by  c orre spondin g polynuclear phen o lsmethylolated.  Th e co m p ou nds ma y  ev en beu s ed if by-produc ts such as  o l ig omers prod u ced  a t the t ime ofthe r e actionfor conve rting int ometh y l olcompounds.  However , even in thisc as e, am oun t of t he  by -prod ucts i s  pr efera bly 10 %by wei ght o rless.
Al though the Resol resinusable  in t hepresent i nve n tio n is notpart icularly r est ric ted,the compo unds di scl o sed a s Re s ol resins in  BP 2 ,0 82,339 arep r e fer able.  Fa v orable  exa mples among themi nclude the com poun d s  wi tha  wei gh t average mole cul ar w eight of  5 00 to 100,0 00, andnu m ber a verage  molec ular we i g ht of 200  to50, 000. When  th em olecula rwe i ght is  too  s mall,cross- l inka b i lity and toleran ce to r epeat e d p rinti ng s becom e  low . When the  molecularweight  istoo l arge, t he re isthe  r isk that s t orage sta bilit y willde teri ora te due  toi n stabi lity .The refore, n e i th e ram ole cula r wei gh t th at is too small no r a molecul ar  we i g ht tha t  i s too largeisprefe r a ble.
A mix t ureo f( 1) alow mo lecula r weigh t  ph en ol deri vat i v e and pol yn
 may_be used_singly, or in combination_of two_or_more. Impurities_such_as dimers or_trimers may be_formed as side products_by condensation of_phenol_compounds when synthesizing the phenol derivatives, these impurities may be contained in the product._However,_it is_preferable_that_the content of the impurities_is 30% or less, preferably_20% or_less.
The polynuclear phenolic cross-linking agent represented by the_general_formula (II) will_be described hereinafter. As is evident from the structural_formula, the polynuclear phenolic cross-linking agent_represented by the_general_formula_(II) has in the_molecule thereof three or more phenol_rings having two or three hydroxymethyl_groups on the rings.
A in the general_formula (II) is an r-valent hydrocarbon_linking group with a carbon_number of_1 to 20, wherein hydrogen_atoms are removed_from the_skeleton composed of_straight-chain, branched or ring alkyl or_aryl groups so_that the resultant group has a_r-valency.
Preferable_examples of the_linking_group_A include_the groups represented_by_the following_structures._
Preferable examples of the polynuclear phenolic_cross-linking_agent having the linking group A in_the molecule and represented_by_the general formula (II)_include those represented by the_formulae (II-1) to (II-6) below, but_the agent_is not_restricted thereto. 
These compounds are obtained by the same process as_in the scheme previously described in_the low molecular weight_phenol derivatives,_by_corresponding polynuclear phenols_methylolated._The compounds_may even be used if by-products such_as oligomers_produced at the time of the_reaction for converting into_methylol_compounds. However, even in this case,_amount of the by-products is preferably_10% by weight or less.
Although_the_Resol_resin usable in the present_invention is not particularly restricted, the_compounds disclosed as_Resol resins in BP 2,082,339 are preferable._Favorable_examples among them include the compounds_with_a weight average molecular weight of_500_to_100,000, and number average molecular_weight of 200 to 50,000. When_the molecular weight is too small, cross-linkability and tolerance_to repeated printings_become low. When the molecular_weight_is_too large, there is the risk that storage stability will_deteriorate due_to instability. Therefore,_neither a molecular weight that is too small nor a_molecular weight that is too large is_preferable.
A mixture of (1) a low molecular weight phenol derivative and_polyn