KR100784218B1 - Radiation-curable polyurethane resin compositions with controlled structures - Google Patents

Abstract

The present invention relates to a radiation curable polyurethane resin composition having reduced viscosity and a process for preparing the composition. The radiation curable polyurethane resin composition

(a) at least one active hydrogen containing compound having X active hydrogen atoms;

(b) at least one polyisocyanate having F isocyanate functional groups; And

(c) at least one radiation curable small molecule having one active hydrogen atom

Comprising a contact product of

Wherein F and X are independently two or more numbers;

At least about 80% of the composition comprises adducts consisting of X moles of polyisocyanates and moles of radiation curable small molecules (F-1) X per mole of active hydrogen containing compound.

Radioactive curable polyurethanes, isocyanates, active hydrogens

Description

Radiation curable polyurethane resin composition having a controlled structure TECHNICAL FIELD [0001] RADIATION-CURABLE POLYURETHANE RESIN COMPOSITIONS WITH CONTROLLED STRUCTURES

The present invention relates to a radiation curable polyurethane resin and a method for producing the same.

Radiation curable polyurethanes are useful in an increasing number of applications, such as coatings, inks, and adhesives. Conventional radiation curable polyurethanes are generally formed from radiation curable oligomers. These oligomers have a relatively high molecular weight, increasing the viscosity of the composition to an unacceptable level for most applications. Accordingly, it is common to add low molecular weight diluents to reduce the viscosity to acceptable processing levels. However, reactive diluents have several disadvantages, such as increasing treatment costs, modifying the physical properties of polyurethanes, being toxic and releasing volatile components upon treatment. Various methods of reducing the viscosity of radiation curable polyurethane resins have been used in the prior art, which methods are described, for example, in US 3,700,643; 4,072,770; 4,188,455; 5,093,386; 5,135,963; 5,624,759; 5,674,921; And 6,852,770, which are incorporated by reference in their entirety. However, no method of the prior art describes a method of reducing the viscosity of the radiation curable polyurethane resin by controlling the structure in the manner described in the present invention. Therefore, it is desirable to produce novel radiation curable polyurethane resin compositions, in which the viscosity decreases and thus requires a reduced level of reactive diluent.

The present invention relates to a novel radiation curable polyurethane resin with reduced viscosity and a process for preparing the composition. The radiation curable polyurethane resin composition includes the following (a) to (c):

(a) at least one active hydrogen containing compound having X active hydrogen atoms;

(b) at least one polyisocyanate having F isocyanate (NCO) functional groups; And

(c) at least one radiation curable small molecule having one active hydrogen atom

Containing a contact product and a reaction product,

Wherein F and X are independently two or more numbers,

At least about 80% by weight of the resin composition comprises an adduct of X moles of polyisocyanate and mole of radiation curable small molecules (F-1) X per mole of active hydrogen containing compound.

In addition, the present invention

(a) contacting at least one polyisocyanate having F isocyanate (NCO) functional groups with at least one active hydrogen containing compound having X active hydrogen atoms to form a prepolymer composition, wherein F and X are independently 2 or more, wherein the prepolymer composition is

(1) contains less than about 1 weight percent of unreacted polyisocyanate;

(2) at least about 80% by weight of a prepolymer of X moles of polyisocyanate per mole of active hydrogen containing compound; And

(b) contacting the prepolymer composition with a sufficient amount of at least one radiation curable small molecule having one active hydrogen atom to form an adduct of X moles of polyisocyanate and moles of radiation curable small molecule (F-1) X per mole of active hydrogen containing compound. Steps to provide

It relates to a method for producing a radiation curable polyurethane resin composition comprising a. A sufficient amount of the radiation curable small molecule provides about 1 equivalent of the radiation curable small molecule per equivalent of unreacted NCO in the prepolymer, ie, the equivalent ratio of active hydrogen to NCO is at least about 1: 1.

In addition, the present invention

(a) forming a prepolymer composition by contacting at least one polyisocyanate having F NCO functional groups with at least one hydrogen containing compound having X active hydrogen atoms such that the equivalent ratio of NCO to active hydrogen is at least about 4: 1. Wherein, F and X are independently two or more; And

(b) unreacted polyisocyanate is removed from the prepolymer composition so that the prepolymer composition is

(1) contains less than about 1 weight percent of unreacted polyisocyanate;

(2) at least about 80% by weight of a prepolymer of X moles of polyisocyanate per mole of active hydrogen containing compound; And

(c) contacting the prepolymer composition with a sufficient amount of one or more radiation curable small molecules having one active hydrogen atom to form an adduct consisting of X moles of polyisocyanate and mole of radiation curable small molecule (F-1) X per mole of active hydrogen containing compound. Steps to provide

It relates to a method for producing a radiation curable polyurethane resin composition comprising a. A sufficient amount of the radiation curable small molecule provides at least about 1 equivalent of the radiation curable small molecule per unreacted NCO equivalent in the prepolymer, ie, the equivalent ratio of active hydrogen to NCO is at least about 1: 1.

Further aspects of the invention

(a) forming a prepolymer composition by contacting a di-isocyanate with at least one radiation curable small molecule having one active hydrogen atom, wherein the prepolymer composition is

(1) contains less than about 1 weight percent of unreacted di-isocyanate;

(2) at least about 80% by weight of a prepolymer of 1 mole of di-isocyanate per mole of radiation curable small molecule; And

(b) contacting the prepolymer composition with at least one active hydrogen-containing compound having X active hydrogen atoms with an equivalent ratio of NCO to active hydrogen of approximately 1: 1 such that X moles of di-isocyanate per mole of active hydrogen-containing compound Providing a side product consisting of a radiation curable small molecule X mole, wherein X is a number of two or more

It includes, a method for producing a radiation curable polyurethane resin composition.

Another aspect of the invention

(a) forming a prepolymer composition by contacting at least one di-isocyanate with at least one radiation curable small molecule having one active hydrogen atom such that an equivalent ratio of NCO to active hydrogen is at least about 4: 1;

(b) unreacted di-isocyanate is removed from the prepolymer composition

(1) the amount of unreacted di-isocyanate in the prepolymer composition is less than about 1 weight percent based on the total weight of the prepolymer;

(2) wherein at least about 80% by weight of the prepolymer composition comprises a prepolymer consisting of one mole of diisocyanate per mole of radiation curable small molecule; And

(c) contacting the prepolymer composition with at least one active hydrogen-containing compound having X active hydrogen atoms so that the equivalent ratio of NCO to active hydrogen is approximately 1: 1 so that X moles of di-isocyanate per mole of active hydrogen-containing compound and radiation Providing an adduct of a curable small molecule X mole, wherein X is a number of two or more

It includes a method of producing a radiation curable polyurethane resin composition using a di-isocyanate, including.

The present invention provides a novel radiation curable polyurethane resin composition having reduced viscosity and a process for preparing the composition. One aspect of the invention is to contact (a) at least one active hydrogen containing compound having at least two active hydrogen atoms, (b) at least one polyisocyanate, and (c) at least one radiation curable small molecule having one active hydrogen atom. And a polyurethane resin composition having a controlled structure, which is formed by. Another aspect of the invention is to contact (a) at least one active hydrogen containing compound having at least two active hydrogen atoms, (b) at least one polyisocyanate, and (c) at least one radiation curable small molecule having one active hydrogen atom. It relates to a method for producing a radiation curable polyurethane resin composition having a structure controlled by.

Radiation curable polyurethane resin component

Active hydrogen-containing compounds

Active hydrogen containing compounds useful for use in the present invention may include any suitable compound having at least two active hydrogen atoms as determined by Zerewittenoff test. Suitable compounds have 2 to 4, especially 2 to 3 active hydrogen atoms. Active hydrogen containing compounds are, for example, -OH; -NH; And / or -SH functional groups. Non-limiting examples of suitable active hydrogen containing compounds include polyols, thiols, amines, amides, urea, or any combination thereof. Preferred are polyols.

Non-limiting examples of polyols suitable for use in the present invention include polyether polyols and polyester polyols. Polyether polyols are hydroxyl-terminated polyethers, such as poly (alkylene ether) glycols such as poly (ethylene ether) glycol, poly (propylene ether) glycol, and poly (tetramethylene ether) glycol, and their And copolymers. Polyether polyols are poly (oxyalkylene) polymers such as poly (oxyethylene), poly (oxypropylene) polymers, trimethyl ethylene oxide polymers, and multivalent compounds including diols and triols such as ethylene glycol, propylene glycol , 1,3-butane diol, 1,4-butane diol, 1,6-hexane diol, neopentyl glycol, diethylene glycol, dipropylene glycol, pentaerythritol, glycerol, diglycerol, trimethylol propane, and similar low Also included are copolymers having terminal hydroxyl groups derived from molecular weight polyols.

In one aspect of the invention, a single high molecular weight polyether polyol may be used. Alternatively, mixtures of high molecular weight polyether polyols can be used, for example bifunctional and trifunctional materials and / or mixtures of materials of different molecular weight or different chemical composition. Non-limiting examples of such di- and tri-functional materials include ethylene glycol, poly (ethylene ether) glycol, propylene glycol, poly (propylene ether) glycol, poly (tetramethylene ether) glycol, glycerol, glycerol-based polyether triol, Trimethylol propane, trimethylol propane-based polyether triol, 1,3-butane diol, 1,4-butanediol, 1,6-hexane diol, neopentyl glycol, polyether quadrol, or any combination thereof Can be mentioned.

Non-limiting examples of useful polyester polyols include reacting dicarboxylic acids with large amounts of diols, for example by reacting adipic acid with ethylene glycol or butanediol, or by reacting lactones with excess diols, such as caprolactone. The thing manufactured by making it react with propylene glycol is mentioned. Non-limiting examples of suitable polyester polyols include hydroxyl-terminated polyesters such as poly (adipic acid ethylene), poly (adipic acid propylene), poly (adipic acid hexamethylene), and ethylene glycol and propylene glycol. And copolymers prepared by copolymerizing the above-mentioned polyesterification together. Non-limiting examples of the copolymer include poly (1,4-butylene-co-adipic acid ethylene) and poly (1,4-butylene-co-adipic acid propylene). Polyester polyols having more than two average functional groups can also be obtained by copolymerizing dicarboxylic acids with diols and small amounts of triols or quadrols such as trimethylol propane, glycerol, and pentaerythritol.

The polyether and polyester polyols are conventional for the preparation of polyurethane prepolymers, which are generally about 400-10,000, and generally 750-1, of the polyol compositions (single compositions or mixtures) used in radiation curable polyurethane resin compositions. It can be mixed to have an average number average molecular weight (M _n ) of 4,000.

Polyisocyanate

Non-limiting examples of polyisocyanate compounds useful in the present invention include aliphatic, cycloaliphatic, and aromatic polyisocyanates such as alkyl polyisocyanates, alkylene polyisocyanates, cycloalkyl polyisocyanates, cycloalkylene polyisocyanates, aryl polyisocyanates , Arylene polyisocyanate, or any combination thereof. In one aspect of the invention, the polyisocyanate is a diisocyanate such as 1,6-hexamethylene diisocyanate (HDI), 2,4-toluene diisocyanate (2,4-TDI), 2,6-toluene diisocyanate ( 2,6-TDI), 4,4'-diphenylmethane diisocyanate (MDI), m-phenylene diisocyanate, p-phenylene diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'- Diisocyanate, 3,3'-dimethylphenylene diisocyanate, 1,4-naphthalene diisocyanate, 1,5-naphthalene diisocyanate, 1,4-tetramethylene diisocyanate, 1,10-decamethylene diisocyanate, 1, 4-cyclohexylene diisocyanate, 4,4'-methylene bis (cyclohexyl isocyanate), 1,5-tetrahydronaphthalene diisocyanate, 4,4'-diphenylene diisocyanate, 2,2,4-trimethylhexa Methyl-1,6-diisocyanate, 1,3-xylylene diisocyanate, 1,4- Silyl diisocyanate, isophorone diisocyanate, and 6-isopropyl-1,3-phenyl diisocyanate, 4-diphenyl-propane diisocyanate, lysine diisocyanate, or any combination thereof. In another aspect of the invention, 2,4-TDI, 2,6-TDI, or any combination thereof may be used in the present invention, such as commercially available mixtures, from about 65 to about 99 weight percent of 2,4 Contains TDI Other suitable isocyanate compounds are mixtures of diisocyanates commercially known as “crude M”, marketed as PAPI by Dough Chemical Company, which is an MDI of about 60 with other isomers and similar higher polyisocyanates. Contains%

Radiation curable small molecules

Radiation curable polyurethane resins are prepared by end-capping polyisocyanate prepolymer molecules with radiation curable small molecules. Upon radiation to the radiation source, the end-capped polyurethane resin molecules form intermolecular crosslinks to provide a rigid flexible film having wear resistance and yellowing resistance. Non-limiting examples of radiation sources include visible light, infrared light, ultraviolet (UV) light, X-rays, electron beams, α-rays, β-rays, and γ-rays. In one embodiment, the radiation is in the form of ultraviolet, visible or electron beams. Suitable radiation curable small molecules for use in the present invention include those having one active hydrogen atom according to the Zerewitenov test. Non-limiting examples of such radiation curable small molecules include 2-hydroxyethyl acrylate; 2-hydroxyethyl methacrylate; 2-hydroxypropyl acrylate; 2-hydroxypropyl methacrylate; 2-hydroxybutyl acrylate; 2-hydroxybutyl methacrylate; N-hydroxymethyl acrylamide; N-hydroxymethyl methacrylamide; 1,4-butanediol monoacrylate; 1,4-butanediol monomethacrylate; 4-hydroxycyclohexyl acrylate; 4-hydroxycyclohexyl methacrylate; 1,6-hexanediol monoacrylate; 1,6-hexanediol monomethacrylate; Neopentyl glycol monoacrylate; Neopentyl glycol monomethacrylate; Monoacrylates and monomethacrylates of ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol; And any combination thereof.

Any additive

The radiation curable polyurethane resins of the present invention may contain one or more optional additives as part of the formulation system. Non-limiting examples of suitable additives include pigments, fillers, flame retardants, auxiliary thermoplastics, tackifiers, plasticizers, free radical inhibitors, photoinitiators, light stabilizers, photosensitizers, UV absorbers, silane coupling agents, leveling agents, hydrolysis stabilizers, Reactive diluents or any combination thereof. The most used additives in formulation systems with radiation curable polyurethane resins are one or more radical initiators, UV absorbers, photoinitiators and reactive diluents. All such additives are materials well known to those skilled in the art of radiation curable polymer systems.

Preparation of Radiation Curable Polyurethane Resin

The radiation curable polyurethane resins of the present invention are prepared from NCO-terminated prepolymers (also called polyisocyanate prepolymers). Prepolymers useful in the present invention are described in U.S. Pat. And 4,786,703, 6,133,415 and 6,280,561.

In one aspect of the invention, the polyisocyanate prepolymers comprise (a) contacting a polyisocyanate with a hydrogen containing compound having at least two active hydrogen atoms as determined by the Zerewitenov test, or (b) It is prepared by contacting with a radiation curable small molecule having one active hydrogen atom as measured by the Zerewitenov test. Polyisocyanates have two or more NCO (equivalent isocyanate) functional groups (F). In one aspect, the contacting step is carried out using a polyisocyanate in a sufficient amount such that the stoichiometric excess is such that the equivalent ratio of NCO to active hydrogen is at least about 4: 1.

In prepolymer synthesis, it is important to maintain polyisocyanates in large amounts of stoichiometric excess relative to active hydrogen containing compounds or to radiation curable small molecules. In the prior art, prepolymers are generally prepared using stoichiometric or slight excess of polyisocyanate. For example, when reacting polyisocyanates with diols, the prior art methods generally employ polyisocyanates to diols in a ratio of about 2: 1, or in the range of about 1.2: 1 to about 3: 1. However, as the amount of polyisocyanate reaches stoichiometric levels, high molecular weight oligomers are formed in large amounts to form radiation curable polyurethane resins with increased viscosity, or hydrogen containing compounds If so, chemically crosslinked products can be formed. Higher molecular weight oligomers mean that the prepolymer molecule contains more than one active hydrogen containing compound (molecule).

Thus, in one aspect of the invention, the polyisocyanate should be used in an amount sufficient such that the equivalent ratio of NCO to active hydrogen is at least about 4: 1. In another aspect, the equivalent ratio of NCO to active hydrogen may range from about 4: 1 to about 20: 1, or from about 4: 1 to about 10: 1, or from about 6: 1 to about 8: 1. The above ratios may be used to prepare polyisocyanate prepolymer compositions having less than about 20% by weight oligomer. In one aspect, the high molecular weight oligomer is included in less than about 10 weight percent of the prepolymer composition, or in another aspect in less than about 5 weight percent.

Excess polyisocyanates also serve to induce the reaction of polyisocyanates with radiation curable small molecules or active hydrogen containing compounds. Thus, in the formation of the prepolymer there is generally no need to accelerate the reaction rate using a catalyst. However, in one aspect of the invention, it is possible to use catalysts which accelerate the reaction of NCO functional groups with active hydrogen atoms.

Temperature can also potentially serve to minimize the amount of oligomers formed in the prepolymer composition. In some cases, as the temperature increases, the ratio of polyisocyanate to active hydrogen containing compound or radiation curable small molecule must be increased to reduce the formation of high molecular weight oligomers. Suitable temperatures for forming the prepolymer composition range from about 20 to about 140 ° C. In one aspect of the invention, the temperature is maintained at about 40 to about 80 ° C.

The prepolymer composition formed according to one aspect of the invention ideally comprises at least about 80% by weight of a "complete" prepolymer. In another aspect, the prepolymer composition comprises at least about 95% by weight of a "complete" prepolymer. In another embodiment, the prepolymer composition comprises at least about 95% of a "complete" prepolymer. By "complete" prepolymer is meant that the stoichiometric prepolymer is formed by the reaction of a polyisocyanate with an active hydrogen containing compound or a radiation curable compound. For example, when using diols as active hydrogen containing compounds, a "complete" prepolymer includes molecules in which the molar ratio of polyisocyanate to diol is 2: 1. When using a triol as the active hydrogen containing compound, the "complete" prepolymer includes molecules in which the molar ratio of polyisocyanate to triol is 3: 1. For radiation curable small molecules with one active hydrogen atom per molecule, a "complete" prepolymer includes molecules in which the molar ratio of polyisocyanate to radiation curable small molecules is 1: 1.

After a suitable contact time for the formation of the prepolymer, for example from about 15 minutes to about 24 hours, any unreacted polyisocyanate should be removed from the prepolymer composition. This is desirable to maximize the amount of “complete” prepolymer in the prepolymer reaction composition. When prepolymers are first prepared by contacting a polyisocyanate with an active hydrogen containing compound, excess polyisocyanate in the prepolymer leaves a large amount of radiation curable small molecule to polyisocyanate when the prepolymer is in contact with a stoichiometric amount of radiation curable small molecules. Undesirable 2: 1 adducts will be formed in significant amounts. When prepolymers are first prepared by contacting polyisocyanates with radiation curable small molecules, an excessive amount of polyisocyanate in the prepolymer leaves large amounts of undesirable oligomers when the prepolymer is in contact with a stoichiometric amount of active hydrogen containing compound. Will be formed in a quantity.

Any suitable method known in the art, such as distillation, evaporation or solvent extraction, may be used in the present invention to remove excess polyisocyanate from the prepolymer before the adduct is formed. Non-limiting examples of separation methods that facilitate the removal of unreacted polyisocyanates include thin-film distillation and wiped-film evaporation. In one aspect of the invention, the concentration of unreacted residual polyisocyanate after separation is less than about 1 weight percent based on the total weight of the prepolymer composition. In another aspect, the concentration of unreacted polyisocyanate is less than 0.5% by weight. In a further aspect, the concentration of unreacted polyisocyanate is less than about 0.1% by weight. After removal of unreacted polyisocyanate, the amount of free isocyanate (ie free NCO functional group) should range from about 0.8 to about 14 weight percent. In another aspect, the free NCO functional group may range from about 1.8 to about 14 weight percent.

After formation of the prepolymer comprising a polyisocyanate and an active hydrogen containing compound, the radiation curable polyurethane resin is end capped to a sufficient amount of one or more radiation curable small molecules having one active hydrogen atom to form poly per mole of active hydrogen containing compound. It can be formed by providing an adduct of X moles of isocyanates and X moles of radiation curable small molecules (F-1). The appropriate amount of radiation curable small molecule will provide about 1 equivalent of the radiation curable small molecule per unreacted NCO equivalent in the polymer, ie the equivalent ratio of active hydrogen to NCO is about 1: 1.

Similarly, in another aspect of the invention, after the formation of the prepolymer containing polyisocyanate and radiation curable small molecules, the radiation curable polyurethane resin can be formed by contacting the prepolymer with at least one active hydrogen containing compound. In one aspect of the invention wherein the polyisocyanate is di-isocyanate, the prepolymer composition is active by contacting at least one active hydrogen containing compound having X active hydrogen atoms such that the equivalent ratio of NCO to active hydrogen is approximately 1: 1. An adduct of X moles of di-isocyanate and X moles of radiation curable small molecule per mole of hydrogen-containing compound is provided, wherein X is a number of two or more.

When preparing a radiation curable polyurethane resin composition according to the present invention, at least about 80% by weight of the radiation curable polyurethane resin composition comprises F isocyanate functional groups and (F-1) X per mole of active hydrogen containing compound having X active hydrogen atoms. And “complete” adducts of radiation curable small molecules made of mole, wherein F and X are two or more. Preferably, F and X are independently 2 or 3, most preferably both 2. In another aspect of the invention, at least about 90% by weight of the resin comprises a "complete" adduct. In another aspect, at least about 95% by weight of the resin comprises a "complete" adduct.

When the polyisocyanate prepolymer is contacted with radiation curable small molecules or active hydrogen containing compounds, it will be preferable to use a catalyst to accelerate the reaction rate. The catalyst can be any compound which catalyzes the reaction of NCO functional groups and active hydrogens, as is well known in the polyurethane art, for example tin catalysts such as dibutyltin dilaurate and amine catalysts such as triethylene And diamines.

Reactive diluents may be added to the radiation curable polyurethane resins of the present invention to lower the viscosity of formulation systems containing radiation cured polyurethane resins to acceptable or desirable viscosities for processing or use. The reactive diluent may be introduced into the final formulation system, added to or packed with the radiation curable polyurethane resin to facilitate handling and transport.

A wide variety of types or combinations of suitable reactive diluents can be used, and the amount and type of reactive diluents affect the viscosity of the formulation system, as well as many other properties including reactivity, cure shrinkage, strength, stretchability, toughness, and the like.

Examples of the reactive diluent include a polymerizable monofunctional vinyl monomer containing one polymerizable vinyl group in a molecule and a polymerizable polyfunctional vinyl monomer containing two or more polymerizable vinyl groups in a molecule.

Suitable polymerizable monofunctional vinyl monomers include acrylates, methacrylates and vinyl ethers. For example, hexyl acrylate, 2-ethylhexyl acrylate, isobornyl acrylate, decyl acrylate, lauryl acrylate, stearyl acrylate, ethoxyethoxyethyl acrylate, lauryl vinyl ether, 2-ethyl Hexylvinyl ether, N-vinyl formamide, isodecyl acrylate, isooctyl acrylate, vinyl-caprolactam, N-vinylpyrrolidone and the like, and mixtures thereof.

Examples of suitable reactive diluents also include polymerizable polyfunctional vinyl monomers such as 1,6-hexanedioldiacrylate, trimethylolpropanetriacrylate, hexanedioldivinylether, triethyleneglycoldiacrylate, pentaerythritoltetraacrylic Acrylates, tripropylene glycol diacrylates, alkoxylated bisphenol A diacrylates, alkoxylated bisphenol A dimethacrylates, alkoxylated hydrogenated bisphenol A diacrylates, alkoxylated hydrogenated bisphenol A dimethacrylates, and mixtures thereof. Can be mentioned.

Comparative Example 1

Synthesis of Polyisocyanate Prepolymers Using Polyisocyanate in Usual Amount

157.2 g (0.902 mol) of toluene diisocyanate (TDI) of approximately 80/20 2,4 / 2,6 were charged to a jacketed glass reactor equipped with a nitrogen blanket and an overhead mechanical stirrer. TDI was stirred and heated to about 80 ° C. 1044.6 g (0.447 mole) of adipic acid polyethylene having a hydroxyl value of about 48 mg KOH / g was heated to approximately 80 ° C. and added to the reactor over about 4 hours. The equivalent ratio of NCO to active hydrogens was approximately 2: 1. The reactor was held at about 80 ° C. for an additional 16 hours to ensure complete reaction. The properties measured for the formed prepolymers are listed in Table 1. The calculated oligomer content in the prepolymer composition was 86% by weight.

Properties of Conventional Prepolymers (Example 1) NCO (% by weight) 2.44 Residual TDI (% by weight) 1.38 Viscosity at 50 ° C (cP) 16,400

Example 2

Synthesis of Polyisocyanate Prepolymers Using Polyisocyanates in High Molecular Stoichiometry

TDI and adipic acid polyethylene were reacted as in Example 1 except that an excess of TDI was added so that the equivalent ratio of NCO to active hydrogen was approximately 8: 1. Unreacted TDI monomer was removed by thin film evaporation to provide a prepolymer having the properties listed in Table 2. The calculated oligomer content was <5 wt% and the prepolymer included> 95 wt% of the desired "complete" prepolymer.

Properties of Prepolymers of the Invention (Example 2) NCO (% by weight) 3.18 Residual TDI (% by weight) <0.10 Viscosity at 50 ° C (cP) 8,340

As described in Tables 1 and 2, the viscosity of the prepolymer (Example 2) formed using a large amount of stoichiometric excess is the viscosity of the prepolymer (Example 1) formed using a conventional amount of TDI. It was about half of. Examples 3 and 4 describe the properties of radiation curable polyurethane resins prepared from the prepolymers of Examples 1 or 2.

Comparative Example 3

Formation of Conventional Radiation Curable Polyurethane Resin

505.55 g (NCO equivalent 0.294) of prepolymer formed in Example 1 were heated to about 75 ° C. in a jacketed glass reactor equipped with a nitrogen blanket and an overhead mechanical stirrer. 0.27 g of 4-methoxyphenol (MEHQ) was added to the prepolymer and mixed for about 15 minutes. Thereafter, 32.68 g (0.281 mol) of 2-hydroxyethyl acrylate (HEA) was charged to the reactor, followed by 2.59 g of a dibutyltin dilaurate catalyst. An exotherm to about 85 ° C. was observed. The reactor was allowed to stand at about 70-80 ° C. for an additional 90 minutes to ensure complete reaction. The viscosity of the resin produced at 50 ° C. was 58,300 cP.

Example 4

Formation of Radiation Curable Polyurethane Resin of the Present Invention

509.12 g (NCO equivalent 0.385) of the prepolymer formed in Example 2 was heated to about 90 ° C. in a jacketed glass reactor equipped with a nitrogen blanket and an overhead mechanical stirrer. 0.28 g MEHQ was added to the prepolymer and mixed for about 15 minutes. Thereafter, 42.58 g (0.367 mol) of HEA were charged to the reactor, followed by 2.73 g of the dibutyltin dilaurate catalyst. An exotherm to about 80 ° C. was observed. The reactor was allowed to stand at about 70-80 ° C. for an additional 90 minutes to ensure complete reaction. The viscosity of the resin produced at 50 ° C. was 23,550 cP.

Comparing the resins of Examples 3 and 4 shows that the viscosity of the resin composition (Example 4) of the controlled structure is about 2.5 smaller than the viscosity of the conventional resin (Example 3). The fact that the viscosity of the resin of controlled structure (Example 4) is as small as 2.5 compared to the viscosity of conventional resin (Example 3) means that the viscosity of the precursor prepolymer of the corresponding controlled structure (Example 2) corresponds This is a surprising result considering the fact that the viscosity is only as low as factor 2.0 than that of ordinary resin (Example 1). Accordingly, the radiation curable polyurethane resin compositions of the present invention will require less reactive diluent to achieve acceptable treatment viscosities as compared to conventional resin compositions.

By using the process of the present invention and selecting the appropriate raw materials known to those skilled in the art, it is possible to produce resins that do not require a reactive diluent.

Another advantage is the ability to prepare resins of higher functional groups (ie> 2) without the problem of physical gel formation in the preparation. The new resins will enable custom / special physical properties of UV-cured polymers as compared to the small molecule crosslinkers (eg diacrylates, triacrylates) currently commonly used.

The present invention provides novel radiation curable polyurethane resin compositions and methods for their preparation, which require a reduced level of reactive diluent to reduce the viscosity thereof by controlling the structure of the radiation curable polyurethane resin composition.

Claims (24)

(a) an active hydrogen containing compound having X active hydrogen atoms; (b) polyisocyanates having F isocyanate functional groups; And (c) radiation curable small molecules with one active hydrogen atom A radiation curable polyurethane resin composition comprising a contact product of Wherein F and X are independently two or more numbers; 80% or more of the resin composition comprises an adduct of X moles of polyisocyanate and mole of radiation curable small molecule (F-1) X per mole of active hydrogen containing compound. The composition of claim 1, wherein at least 90% of the resin composition comprises adducts consisting of X moles of polyisocyanate and moles of radiation curable small molecules (F-1) X per mole of active hydrogen containing compound. The composition of claim 1, wherein X is two. The composition of claim 1 wherein X is 3. The composition of claim 1 wherein said active hydrogen containing compound is a polyol. The composition of claim 5 wherein said polyol is a polyether polyol, a polyester polyol, or a combination thereof. 7. The composition of claim 6, wherein said polyol is a polyether polyol. The composition of claim 6 wherein said polyol is a polyester polyol. The composition of claim 1 wherein said polyisocyanate is diisocyanate. The method of claim 9, wherein the diisocyanate is 1,6-hexamethylene diisocyanate, m-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane A composition which is a diisocyanate, isophorone diisocyanate, 4,4'-methylene bis (cyclohexyl isocyanate) or a combination thereof. The composition of claim 9 wherein said diisocyanate is 2,4-toluene diisocyanate, 2,6-toluene diisocyanate or combinations thereof. The method of claim 1, wherein the radiation curable small molecule is 2-hydroxyethyl acrylate; 2-hydroxyethyl methacrylate; 2-hydroxypropyl acrylate; 2-hydroxypropyl methacrylate; 2-hydroxybutyl acrylate; 2-hydroxybutyl methacrylate; N-hydroxymethyl acrylamide; N-hydroxymethyl methacrylamide; 1,4-butanediol monoacrylate; 1,4-butanediol monomethacrylate; 4-hydroxycyclohexyl acrylate; 4-hydroxycyclohexyl methacrylate; 1,6-hexanediol monoacrylate; 1,6-hexanediol monomethacrylate; Neopentyl glycol monoacrylate; Neopentyl glycol monomethacrylate; Monoacrylates and monomethacrylates of ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol; Or combinations thereof. The method of claim 1 wherein the pigment, filler, flame retardant, auxiliary thermoplastic component, tackifier, plasticizer, free radical inhibitor, photoinitiator, light stabilizer, photosensitizer, UV absorber, silane coupling agent, leveling agent, hydrolysis stabilizer, reactive diluent or A composition further comprising a combination thereof. As a manufacturing method of a radiation curable polyurethane resin composition, a) forming a prepolymer composition by contacting a polyisocyanate having F isocyanate (NCO) functional groups with an active hydrogen containing compound having X active hydrogen atoms, wherein F and X are independently two or more numbers, The prepolymer composition is (1) contains less than 1% by weight of unreacted polyisocyanate; (2) at least 80% by weight of a prepolymer of X moles of polyisocyanate per mole of active hydrogen containing compound; And (b) contacting the prepolymer composition with a sufficient amount of radiation curable small molecule having one active hydrogen atom to provide an adduct of X moles of polyisocyanate and mole of radiation curable small molecule (F-1) X per mole of active hydrogen containing compound. step How to include. As a manufacturing method of a radiation curable polyurethane resin composition, (a) forming a prepolymer composition by contacting a polyisocyanate having F isocyanate functional groups with an active hydrogen-containing compound having X active hydrogen atoms such that an equivalent ratio of NCO to active hydrogen is 4: 1 to 20: 1. Wherein F and X are each independently two or more numbers; And (b) (1) the amount of unreacted polyisocyanate in the prepolymer composition is less than 1 weight percent based on the total weight of the prepolymer composition; (2) removing unreacted polyisocyanate from the prepolymer composition such that at least 80% of the prepolymer composition comprises a prepolymer consisting of X moles of polyisocyanate per mole of active hydrogen containing compound; And (c) contacting the prepolymer with a radiation curable small molecule having one active hydrogen atom  How to include. The process of claim 15 wherein the equivalent ratio of NCO to active hydrogen in step (c) is 1: 1. The method of claim 15 wherein X is 2 or 3 and the active hydrogen containing compound is a polyol. 18. The method of claim 17, wherein said polyisocyanate is diisocyanate. 19. The method of claim 18, wherein said diisocyanate is 2,4-toluene diisocyanate, 2,6-toluene diisocyanate or combinations thereof. 19. The method of claim 18, wherein the radiation curable small molecule is 2-hydroxyethyl acrylate; 2-hydroxyethyl methacrylate; 2-hydroxypropyl acrylate; 2-hydroxypropyl methacrylate; 2-hydroxybutyl acrylate; 2-hydroxybutyl methacrylate; N-hydroxymethyl acrylamide; N-hydroxymethyl methacrylamide; 1,4-butanediol monoacrylate; 1,4-butanediol monomethacrylate; 4-hydroxycyclohexyl acrylate; 4-hydroxycyclohexyl methacrylate; 1,6-hexanediol monoacrylate; 1,6-hexanediol monomethacrylate; Neopentyl glycol monoacrylate; Neopentyl glycol monomethacrylate; Monoacrylates and monomethacrylates of ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol; Or combinations thereof. As a manufacturing method of a radiation curable polyurethane resin composition, (a) forming a prepolymer composition by contacting a di-isocyanate with a radiation curable small molecule having one active hydrogen atom, wherein the prepolymer composition is (1) contains less than 1% by weight of unreacted di-isocyanate; (2) at least 80% by weight of a prepolymer of 1 mole of di-isocyanate per mole of radiation curable small molecule; And (b) contacting the prepolymer composition with an active hydrogen-containing compound having X active hydrogen atoms so that the equivalent ratio of NCO to active hydrogen is 1: 1, such that X moles of di-isocyanate per mole of active hydrogen-containing compound and radiation curable small molecule X Providing a molar adduct, wherein X is a number of two or more How to include. As a manufacturing method of a radiation curable polyurethane resin composition, (a) forming a prepolymer composition by contacting a di-isocyanate with a radiation curable small molecule having one active hydrogen atom such that an equivalent ratio of NCO to active hydrogen is between 4: 1 and 20: 1; (b) removing the unreacted polyisocyanate from the prepolymer composition to obtain a prepolymer composition. (1) contains less than 1% by weight of unreacted di-isocyanate; (2) at least 80% of a prepolymer molecule consisting of one mole of di-isocyanate per mole of radiation curable small molecule; And (c) contacting the prepolymer composition with an active hydrogen containing compound having X active hydrogen atoms, wherein X is a number of two or more How to include. The method of claim 22 wherein the equivalent ratio of NCO to active hydrogen in step (c) is 1: 1. The method of claim 23, wherein X is 2 or 3.