JP2001055540A - Polyurethane-based primer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyurethane-based primer having good adhesion between olefin base films or sheets and electron beam curable resins or ultraviolet curable resins and excellent weatherability. SOLUTION: This polyurethane-based primer to be used between an olefin based film or sheet and an electron beam curable or ultraviolet curable surface coating material is a polyurethane resin having, as the constituting components, at least (A) an organic diisocyanate, (B) an acrylic polyol, (C) a long-chain polyol excluding acrylic polyol (B), (D) a compound having an ethylenically unsaturated bond and an active hydrogen group and, preferably, (E) a chain extender with a content of acrylic polyol (B) in the polyurethane resin of 20-80 mass %. It is further preferred to incorporate 1-50 mass pts. polyisocyanate curing agent into 100 mass pts. polyurethane resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a polypropylene,
The present invention relates to a polyurethane-based primer used between a polyolefin-based film or sheet such as polyethylene and an electron beam-curable or ultraviolet-curable surface coating agent.

[0002]

2. Description of the Related Art Polyolefin resins such as polypropylene and polyethylene have inferior abrasion resistance as compared with polyvinyl chloride. In order to improve this, it has been proposed to coat an electron beam curable resin or an ultraviolet curable resin as a protective layer on the surface of a polyolefin resin. However, since a polyolefin resin and an electron beam-curable resin or an ultraviolet-curable resin have poor adhesion, use of a primer is being studied. For example, Japanese Patent Application Laid-Open
No. 61677 proposes a method in which a primer is applied to a substrate, an ultraviolet-curable coating agent is applied, a film is laminated thereon, and then the film is irradiated with ultraviolet light to remove the film.

[0003]

An object of the present invention is to provide a polyurethane primer which has good adhesion between an olefin sheet or film and an electron beam-curable resin or an ultraviolet-curable resin and has weather resistance. Aim.

[0004]

Means for Solving the Problems As a result of intensive studies and studies, the present inventors have found that a primer using a polyurethane resin containing organic diisocyanate, acrylic polyol and the like can solve the above problems. Was completed.

That is, the present invention provides the following (1) to (4)
It is. (1) The polyurethane-based primer used between the olefin-based film or sheet and the electron beam-curable or ultraviolet-curable surface coating agent comprises at least (A) an organic diisocyanate, (B) an acrylic polyol, and (C) an acrylic Long-chain polyols other than polyols,
And (D) a polyurethane resin containing a compound containing an ethylenically unsaturated bond and an active hydrogen group, wherein the content of the acrylic polyol (B) in the polyurethane resin is 20 to 80% by mass. The polyurethane-based primer described above.

(2) The polyurethane primer used between the olefin-based film or sheet and the electron beam-curable or ultraviolet-curable surface coating agent comprises at least (A) an organic diisocyanate, (B) an acrylic polyol, C) a polyurethane resin comprising a long-chain polyol other than an acrylic polyol, (D) a compound containing an ethylenically unsaturated bond and an active hydrogen group, and (E) a chain extender, wherein (B) The polyurethane-based primer, wherein the content of the acrylic polyol is 20 to 80% by mass.

(3) The polyurethane primer according to (2), wherein (E) the chain extender is an alicyclic polyol and / or an alicyclic polyamine.

(4) A polyurethane primer comprising 100 parts by mass of the polyurethane resin according to any one of (1) to (3) and 1 to 50 parts by mass of a polyisocyanate curing agent.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
(A) The organic diisocyanate used in the present invention includes 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and 2,2'- Diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, 1,4-naphthylene diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, o-xylylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, tetramethyl xylylene Range isocyanate, 4,4'-diphenyl ether diisocyanate, 2-nitrodiphenyl-4,
4'-diisocyanate, 2,2'-diphenylpropane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,
4'-diphenylpropane diisocyanate, 3,3 '
Aromatic diisocyanates such as -dimethoxydiphenyl-4,4'-diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, 2-methyl-1,5-pentane diisocyanate, 3-methyl-
Alicyclics such as aliphatic diisocyanates such as 1,5-pentane diisocyanate and lysine diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated tetramethyl xylylene diisocyanate, and cyclohexyl diisocyanate Diisocyanates and mixtures of two or more of these, urethane-modified, allophanate-modified, urea-modified, biuret-modified, uretdione-modified, uretoimine-modified, isocyanurate-modified, carbodiimide-modified and the like of these organic diisocyanates, It may be any known organic diisocyanate.

In the present invention, in consideration of the weather resistance of the polyurethane primer, the organic diisocyanate (A) preferably contains 50 to 100 mol% of an aliphatic diisocyanate and / or an alicyclic diisocyanate, and more preferably 80 to 100 mol%. Those containing 100 mol% are preferred, and those containing 100 mol% of alicyclic diisocyanate are most preferred. When the amount of the aliphatic diisocyanate and / or the alicyclic diisocyanate is less than the lower limit, the coating film is liable to yellow and the adhesion is reduced. Among the above organic diisocyanates, isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate are particularly preferred.

The acrylic polyol (B) used in the present invention preferably has a hydroxyl value of 3 to 12 KOH mg / g.
Furthermore, it is 3.5 to 11.5 KOHmg / g. The average number of functional groups is preferably from 1 to 2.2, more preferably from 1.5 to 2. (B) When the hydroxyl value of the acrylic polyol is less than the lower limit, the obtained polyurethane resin is too hard, and the adhesion tends to be reduced. On the other hand, when the ratio exceeds the upper limit, the obtained polyurethane resin tends to have low blocking resistance. When the average number of functional groups is less than the lower limit, the molecular weight of the obtained polyurethane resin tends to be small, and the weather resistance tends to be low. If the upper limit is exceeded, gelation is likely to occur during the production of the polyurethane resin.

The acrylic polyol (B) is obtained by a polymerization reaction of an unsaturated double bond-containing compound (acrylic monomer). The polymerization reaction is usually a radical polymerization reaction. The acrylic monomers include alkyl acrylate, cycloalkyl acrylate, phenyl acrylate,
Acrylates such as benzyl acrylate and glycidyl acrylate, methacrylates such as alkyl methacrylate, cycloalkyl methacrylate, phenyl methacrylate, benzyl methacrylate and glycidyl methacrylate, vinyl acetate, Vinyl ester compounds such as vinyl propionate; vinyl alkyl ethers such as vinyl methyl ether; vinyl ether compounds such as vinyl cyclohexyl ether, vinyl phenyl ether, vinyl benzyl ether and vinyl glycidyl ether; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile Compounds, styrene, vinyltoluene, ethylenically unsaturated double bond-containing aromatic compounds such as α-methylstyrene, maleic diesters such as dialkyl maleate, Fumaric acid diesters such as dialkyl malate; itaconic acid diesters such as dimethyl itaconate; dialkylacrylamides such as N, N-dimethylacrylamide; heterocyclic vinyl compounds such as N-vinylpyrrolidone and 2-vinylpyridine; 2-hydroxyethyl acrylate, hydroxypropyl acrylate, polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, ε-caprolactone adduct of 2-hydroxyethyl acrylate, 2-
Β-methyl-valerolactone adduct of hydroxyethyl methacrylate, glycerol monoacrylate, acrylates such as glycerol diacrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, polyethylene glycol monoacrylate, polypropylene glycol monomethacrylate, 2- Ε-caprolactone adduct of hydroxyethyl methacrylate, β-methyl-valerolactone adduct of 2-hydroxyethyl methacrylate, glycerol monomethacrylate, methacrylates such as glycerol dimethacrylate, allyl alcohol, glycerol monoallyl ether, glycerol diallyl ether and the like Allyl compounds and the like can be mentioned. Preferred among these are 2-hydroxyethyl acrylate, 2
Active hydrogen group-containing ethylenically unsaturated monomers such as ε-caprolactone adduct of -hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and β-methyl-valerolactone adduct of 2-hydroxyethyl methacrylate. The acrylic polyol used in the present invention is 2-hydroxyethyl acrylate,
A hydroxyl group-containing acrylic monomer selected from hydroxyethyl methacrylate and an acrylic monomer selected from an alkyl acrylate and an alkyl methacrylate (particularly preferably, methyl acrylate and methyl methacrylate) are preferable as essential components.

The polyurethane resin (B) of the present invention
The acrylic polyol content is from 20 to 80% by mass, preferably from 25 to 75% by mass, particularly from 30 to 7% by mass.
0% by weight is most preferred. If the (B) acrylic polyol content is less than the lower limit, the resulting polyurethane resin has poor blocking resistance. If it exceeds the upper limit, the adhesion will be reduced.

The long-chain polyol other than the acrylic polyol (C) used in the present invention has a number average molecular weight of 500 to 1
000, preferably 800-5,000 polyester polyols, polyamide ester polyols, polycarbonate polyols, polyether polyols,
Polyether ester polyols, polyolefin polyols, animal and plant polyols and the like can be mentioned. When the number average molecular weight of the long-chain polyol other than the (C) acrylic polyol exceeds the upper limit, the solution viscosity of the obtained polyurethane resin becomes too high, and the workability tends to deteriorate. On the other hand, if it is less than the lower limit, the blocking resistance tends to deteriorate. In the present invention, a polyester polyol is preferred when adhesion is important, and a polycarbonate polyol is preferred when durability is important.

Examples of the polyester polyol include known phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, succinic acid, tartaric acid, oxalic acid, malonic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, curtaconic acid, Azelaic acid, sebacic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, 1,4-
Cyclohexyldicarboxylic acid, α-hydromuconic acid,
one or more kinds of dicarboxylic acids or anhydrides such as β-hydromuconic acid, α-butyl-α-ethylglutaric acid, α, β-diethylsuccinic acid, maleic acid, and fumaric acid; ethylene glycol; Propanediol, 1,4
-Butanediol, 1,5-pentanediol, 1,6
-Hexanediol, 1,8-octanediol, 1,
9-nonanediol, diethylene glycol, cyclohexane-1,4-diol, cyclohexane-1,4-diol
Linear low molecular weight polyols such as dimethanol, bis (β-hydroxyethyl) benzene, xylylene glycol, glycerin, pentaerythritol, 1,2-propanediol, 1,2-butanediol, 1,3-butane Diol, 3-methyl-1,5-pentanediol, 3,3-dimethylolheptane, diethylene glycol, dipropylene glycol, neopentyl glycol, dipropylene glycol, dimer acid diol, ethylene oxide or propylene oxide adduct of bisphenol A, It is obtained from a polycondensation reaction with one or more kinds of low molecular polyols having a side chain such as trimethylolpropane. Further, ε-caprolactone, alkyl-substituted ε
Lactone-based polyester polyols obtained from ring-opening polymerization of cyclic ester (so-called lactone) monomers such as -caprolactone, δ-valerolactone, and alkyl-substituted δ-valerolactone. Further, part of the low molecular polyol hexamethylene diamine, isophorone diamine,
A low molecular weight polyamine such as monoethanolamine or a low molecular weight amino alcohol may be used. In this case, a polyester-amide polyol is obtained. In the present invention, preferred polyester polyols are polyester polyols obtained from dicarboxylic acids having 2 to 10 carbon atoms and low molecular weight diols having 2 to 8 carbon atoms, and further, aliphatic dicarboxylic acids having 4 to 8 carbon atoms and carbon atoms. 2-8
The most preferred is a polyester polyol comprising a low molecular weight diol having a side chain alkyl group.

The polycarbonate polyol is obtained by a dealcoholation reaction or a dephenolization reaction of at least one of the above-mentioned low molecular weight diols and low molecular weight triols of the polyester polyol with ethylene carbonate, diethyl carbonate, and diphenyl carbonate. In the present invention, a preferred polycarbonate polyol is a polycarbonate polyol obtained from a low molecular weight diol having 2 to 8 carbon atoms.

Examples of the polyether polyol include homopolymers and copolymers of epoxides such as ethylene oxide, propylene oxide, and tetrahydrofuran, and cyclic ethers.

As the polyetherester polyol, there is a copolyol obtained from the above-mentioned polyether polyol and the above-mentioned dicarboxylic acid. In addition, there are those obtained by the reaction of the above-mentioned polyester or polycarbonate with epoxide or cyclic ether.

Examples of the polyolefin polyol include polybutadiene having two or more hydroxyl groups, hydrogenated polybutadiene, polyisoprene, and hydrogenated polyisoprene.

The animal and plant based polyols include castor oil based polyols and silk fibroin.

The number average molecular weight is from 500 to 10,000.
0 and an average of at least one active hydrogen group in one molecule, epoxy resin, polyamide resin, polyester resin, acrylic resin, rosin in addition to dimer acid polyol and hydrogenated dimer acid polyol. resin,
Active hydrogen group-containing resins such as urea resins, melamine resins, phenol resins, coumarone resins, and polyvinyl alcohol can also be used.

The compound (D) containing an ethylenically unsaturated bond and an active hydrogen group used in the present invention is a compound represented by the formula (1). By using (D) an ethylenically unsaturated bond and an active hydrogen group-containing compound, an ethylenically unsaturated bond is introduced into the polyurethane resin and reacts with an electron beam-curable resin or an ultraviolet-curable resin. Or, it can strongly adhere to the sheet.

[0023]

Embedded image (R _{1 to} R ₃ represent a hydrogen atom, a halogen atom, and a monovalent organic group, and may be the same or different.
₄ represents a divalent organic group. X represents an active hydrogen group. )

The preferred compound (D) having an ethylenically unsaturated bond and an active hydrogen group in the present invention is that R ₁ and R ₂ are hydrogen, R ₃ is H or an alkyl group having 1 to 3 carbon atoms, and X is a hydroxyl group. It is something that is. Preferred examples of the compound (D) containing an ethylenically unsaturated bond and an active hydrogen group include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate,
-Hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, and their ε-caprolactone adducts.

The amount of the ethylenically unsaturated bond introduced in the present invention is preferably 0.010 to 0.100 mmol / g, more preferably 0.012 to 0.098 mmol / g, and particularly preferably 0.012 to 0.060 mmol / g. g is most preferred. If the amount of the ethylenically unsaturated bond introduced is too small, the adhesion to the electron beam-curable resin or the ultraviolet-curable resin tends to be reduced. On the other hand, when the amount is too large, the molecular weight of the polyurethane resin becomes small, so that the strength and durability tend to be reduced.

In order to improve blocking resistance, weather resistance and the like, it is preferable to use (E) a chain extender.
(E) The chain extender has a number average molecular weight of less than 500 and has two or more active hydrogen groups in one molecule. Specifically, low-molecular-weight polyols (having a linear and / or side chain) used in the above-mentioned polyester polyols, and N-alkyldiamines such as N-methyldiethanolamine, N-methyldipropanolamine and N-ethyldiethanolamine are used. N-aryl dialkanolamines such as alkanolamines, N-phenyldiethanolamine and N-phenyldipropanolamine; N-alkyl dialkanolamines such as N-methyldiethanolamine, N-methyldipropanolamine and N-ethyldiethanolamine And low molecular weight polyamines such as N-aryl dialkanolamines such as N-phenyldiethanolamine and N-phenyldipropanolamine, and low molecular weight amino alcohols. These can be used as one kind or as a mixture of two or more kinds. Preferred chain extenders in the present invention are
An alicyclic diol and / or an alicyclic diamine having good solubility and capable of imparting durability, specifically, cyclohexane-1,4-diol and cyclohexane-
1,4-dimethanol, isophoronediamine, hydrogenated methylenebisaniline, hydrogenated xylylenediamine and the like, particularly cyclohexane-1,4-dimethanol,
Isophorone diamine is preferred. The combination of the two is most preferable.

For adjusting the number average molecular weight of the obtained polyurethane resin, it is preferable to use a reaction terminator. Examples of the reaction terminator include monoalcohols such as methanol and ethanol; monoamines such as ethylamine, propylamine and dibutylamine; aminoalcohols such as monoethanolamine, diethanolamine, N-methyldiethanolamine and N-phenyldipropanolamine. And an amino alcohol is preferred. In some cases, low-molecular polyols and low-molecular polyamines used for the above-mentioned polyester polyol and polyester-amide polyol can also be used.

As the method for synthesizing the polyurethane resin used in the present invention, a known method is used. That is, (1) a method in which an active hydrogen group component and an organic diisocyanate are reacted under a condition of an excess of an active hydrogen group until a predetermined molecular weight is reached (one-shot method); To obtain a isocyanate group-containing prepolymer, then extend the chain of the prepolymer with a low molecular weight glycol or a low molecular weight diamine and react until the prepolymer reaches a predetermined molecular weight (prepolymer method).

As the reaction catalyst, a known so-called urethanization catalyst can be used. Specific examples include organic metal compounds such as dibutyltin dilaurate and dioctyltin dilaurate; organic amines such as triethylenediamine and triethylamine; and salts thereof.

The reaction device of the polyurethane resin used in the present invention may be any device as long as the above-mentioned reaction can be achieved. For example, mixing and kneading of a reaction vessel equipped with a stirrer, a kneader, a single-screw or multi-screw extrusion reaction device, etc. Device. A preferred method for synthesizing the polyurethane resin in the present invention is a prepolymer method in a solution.

The preferred prepolymer method in solution will be described in more detail. In producing the polyurethane resin, first, (B) an acrylic polyol, (C) a long-chain polyol other than the acrylic polyol, (D) a compound containing an ethylenically unsaturated bond and an active hydrogen group, and (E) a chain extension containing a hydroxyl group When an agent is used, this chain extender is dissolved in a ketone or ester having no active hydrogen group, a hydrocarbon solvent, or the like.

After the organic diisocyanate (A) is added to the above-mentioned polyol solution and a urethanation catalyst is added as required, the reaction temperature is raised to 30 to 100 ° C., preferably 50 to 100 ° C.
The reaction is carried out at 80 ° C. for several hours to synthesize an isocyanate group-containing urethane prepolymer solution. At this time, the molar ratio (R value) of isocyanate group / hydroxyl group is 1.1 to 2.5.
Is preferable, and especially 1.1 to 2.0 is preferable.

When the R value is less than 1.1, the durability and blocking resistance of the finally obtained polyurethane primer are reduced. If the R value exceeds 2.5,
The solubility and adhesion of the polyurethane resin to the solvent are reduced.

The thus obtained isocyanate group-containing urethane prepolymer solution is added with a low molecular diamine (E) chain extender to carry out a chain extension reaction. The reaction terminator is preferably used as described above,
The reaction time is preferably simultaneous with the reaction of the low molecular diamine (simultaneous termination reaction and chain extension reaction) or after the reaction of the low molecular diamine (terminating reaction after the chain extension reaction). preferable. By reacting at a reaction temperature of 30 to 80 ° C., preferably 30 to 50 ° C. until the isocyanate group disappears,
A solution of the desired polyurethane resin is obtained.

The number average molecular weight of the polyurethane resin is measured by a gel permeation chromatography (GPC) method using a polystyrene calibration curve, and is preferably from 5,000 to 100,000, and particularly preferably 8,000.
~ 50,000 is preferred. Number average molecular weight is 5,000
If it is less than the above, the durability decreases. Number average molecular weight is 10
If it exceeds 000, the dynamics will be poor and the workability will be poor.

The polyurethane-based primer of the present invention is obtained by adding the above-mentioned polyurethane resin to a pigment, a dye, a thixotropic agent, an antioxidant, an ultraviolet absorber, an antifoaming agent, a thickener, a dispersing agent, a surfactant, a fungicide. Additives such as agents, antibacterial agents, preservatives, catalysts, fillers, and the like, and auxiliary binders such as nitrified cotton can be used.

The polyurethane primer of the present invention is preferably dissolved in a solvent from the viewpoint of workability and the like. Examples of the organic solvent include aromatic hydrocarbon solvents such as toluene and xylene; aliphatic hydrocarbon solvents such as pentane, hexane and octane; alicyclic hydrocarbon solvents such as cyclopentane, cyclohexane and methylcyclohexane; , Methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, ketone solvents such as methylcyclohexanone, diethyl ether, 1,4-dioxane, ether solvents such as tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol monomethyl ether acetate, Cellosolve solvents such as propylene glycol dimethyl ether and propylene glycol monomethyl ether acetate, and monobasic ester solvents such as ethyl acetate and butyl acetate Dimethyl adipate, dimethyl succinate, dibasic esters such as dioctyl phthalate, dimethyl formamide, dimethyl acetamide, not particularly limited as long as it is inactive to the isocyanate group, such as N- methylpyrrolidone. Also, an alcohol solvent such as isopropanol can be used as a diluting solvent at the time of the reaction between the isocyanate group and the amino group or after the reaction is completed. In the present invention, toluene is preferably not used because toluene tends to remain on the olefin-based substrate.

Further, in the present invention, it is preferable to use a polyisocyanate curing agent because strength and durability are improved.

The addition amount of the polyisocyanate curing agent is 1 to 50 parts by mass with respect to 100 parts by mass of the polyurethane resin (in terms of each solid content). As the polyisocyanate curing agent, for example, commercially available from Nippon Polyurethane Industry Co., Ltd., hexamethylene diisocyanate-modified type Coronate (registered trademark) HX, coronate HL, tolylene diisocyanate-modified type coronate L, coronate 2030, coronate 2031 And these may be used alone or as a mixture.

The polyurethane primer of the present invention was able to improve the adhesion between a polyolefin sheet or film and an electron beam-curable resin or an ultraviolet-curable resin. The primer has sufficient weather resistance to withstand practical use.

[0041]

The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In addition,
In the examples, "parts" indicates parts by mass, and "%" indicates% by mass.

Synthesis Example 1 In a reactor equipped with a stirrer, a thermometer, an Aline cooling tube and a nitrogen gas introduction tube, 132.8 parts of polyol A, AP-
190.0 parts, 38.3 parts of CHDM, 1.1 parts of HEA, and 100 parts of MEK were charged and uniformly stirred.
114.0 parts of IPDI in this polyol solution, DOT
0.06 parts of DL was charged and reacted at 70 ° C. for 3 hours to obtain an isocyanate group-containing urethane prepolymer solution. In this prepolymer solution, 110 parts of MEK, M
After adding 165 parts of IBK and making it uniform, MEK was added to 100 parts.
, IPA, 31 parts, IPDA, 17.2 parts, and MEA, 0.6 part, were added at once.
The reaction was continued until the peak of the isocyanate group by FT-IR disappeared.
-1 was obtained. PU-1 has a solid content of 38.1%, a viscosity at 25 ° C of 4,800 mPa · s, and a number average molecular weight of 17,
000, the appearance was clear.

Synthesis Examples 2 to 5 and Synthesis Comparative Examples 1 to 4 Using the same apparatus and reaction method as in Example 1 and using the raw materials described in Tables 1 and 2, polyurethane primer PU-
2 to 5, 8 to 11 were obtained. In Synthesis Example 4 and Synthesis Comparative Example 4, MEK was used in the entire amount of the amine solution, and was not used during the prepolymerization reaction.

Synthesis Example 6 In a reactor similar to that of Example 1, 56.9 of polyol A was added.
Parts, 665.0 parts of AP-1, 16.4 parts of CHDM,
0.6 parts of HEA and 100 parts of MEK were charged and uniformly stirred. 40.1 parts of IPDI in this polyol solution,
0.06 parts of DOTDL was charged and reacted at 70 ° C. As the viscosity increased with the progress of the reaction, MEK, M
Diluted with IBK (MEK preparation total amount: 155 parts, MI
BK charge: 35 parts). When the peak of the isocyanate group disappeared by FT-IR, 31 parts of IPA was charged to obtain a polyurethane resin PU-6 for a primer.
PU-6 has a solid content of 38.1% and a viscosity at 25 ° C of 80.
0 mPa · s, the number average molecular weight was 20,000, and the appearance was clear.

Synthesis Example 7 Polyurethane resin PU-7 for primer was prepared using the same equipment and reaction method as in Example 6 and using the raw material amounts shown in Table 1.
I got

Synthetic Comparative Examples 5 and 6 Comparative Example 5 shows the polyurethane resin (P) obtained in Comparative Example 1.
U-8) is obtained by adding the same amount of AP-1 as polyurethane resin in terms of solid content to U-8). Comparative Example 6 shows that the polyurethane resin (PU-9) obtained in Comparative Example 2
-1 in the same amount as the polyurethane resin in terms of solid content. Resin solutions (P) obtained in Synthesis Comparative Examples 5 and 6
U-12, 13) caused phase separation.

[Table 1]

[0047]

[Table 2]

Each synthesis example, synthesis comparative example, and Tables 1 and 2
Are shown below. Polyol A: Polyester diol composed of adipic acid and 3-methyl-1,5-pentanediol Number average molecular weight = 1,000 Polyol B: Polyester diol composed of adipic acid and neopentyl glycol Number average molecular weight = 1,000 AP-1 : Methyl methacrylate / 2-hydroxyethyl acrylate-based acrylic polyol Hydroxyl value = 5.6 mg KOH / g (in terms of solid content) Average number of functional groups = 1.98 Methyl isobutyl ketone solution with 40% solid content AP-2: Methyl methacrylate / 2-hydroxyethyl acrylate-based acrylic polyol Hydroxyl value = 5.6 mgKOH / g (in terms of solid content) Average number of functional groups = 1.98 A toluene solution having a solid content of 40% IPDI: isophorone diisocyanate HEA: 2-hydroxyacrylate CHDM : Cyclohexane-1,4-dimethanol IPDA: isophoronediamine MEA: monoethanolamine DOTDL: dioctyltin dilaurate MEK: methyl ethyl ketone MIBK: methyl isobutyl ketone IPA: isopropanol Number average molecular weight measurement method: gel permeation chromatography by polystyrene calibration curve Acrylic polyol content: Calculated from the charged amount.

[Evaluation of Primer] Example 1 Primer A was obtained by mixing 100 parts of PU-1 and 3.8 parts of Coronate HX. The adhesion, blocking resistance and weather resistance of this primer were evaluated. Coronate HX: Nippon Polyurethane Industry Co., Ltd. product Isocyanurate-modified polyisocyanate of hexamethylene diisocyanate

(1) Adhesion The primer was treated with a bar coater on a discharge-treated surface of a 15 μm-thick corona discharge-treated stretched polypropylene (hereinafter abbreviated as PP) film, and a 15 μm-thick corona discharge-treated polyethylene film (hereinafter PE and PE). (Abbreviated), heated at 70 ° C. for 30 seconds, and aged at room temperature for 1 day. Then, a cellophane tape was stuck on the coated surface, and this was rapidly peeled off. The primer was applied to PP, heated at 70 ° C. for 30 seconds, and aged at room temperature for one day. Then, an acrylic electron beam-curable resin was applied to the primer application surface, and a 5 Mrad electron beam was applied for 1 second. After irradiation, a cellophane tape was similarly adhered to the acrylic electron beam-curable resin-coated surface, and this was rapidly peeled off. Primer coating amount: 3 g / m ^{2 in} resin content Electron curable resin coating amount: 5 g / m ^{2 in} resin content

(2) Blocking resistance A primer was applied to the discharge-treated surface of the PP film in the same manner as described above, aged at 40 ° C. for 7 days, then superposed on the surface and back, and treated at 50 ° C. and 80 RH% for 24 hours. The blocking resistance was evaluated by applying a load of 0.5 MPa with a blocking tester for a period of time. Amount of primer applied: 3 g / m ² evaluation in terms of resin content ：: Peeling without any resistance when peeling, and no coating film falling off. Δ: The resistance when peeling was slightly large, and some of the coating film fell off. X: The resistance at the time of peeling is large, and the coating film has fallen off.

(4) Weather resistance A primer was applied to the discharge-treated surface of the PP film in the same manner as described above, aged at 40 ° C. for 7 days, allowed to stand at room temperature for 1 day, and then subjected to Q-PANEL. After the following cycle was repeated 10 times, a cellophane tape was stuck on the coated surface, and this was rapidly peeled off. Condition of one cycle by QUV tester: 70 ° C. × 8 hours (Dry) + 50 ° C. × 4 hours (Wet) Irradiation energy: 0.59 (W / m ² / nm) Primer coating amount: 3 g / m ^{2 in} resin content

Examples 2 to 7, Comparative Examples 1 to 4 Primers were prepared and evaluated in the same manner as in Example 1 except that PU-1 in Example 1 was replaced with PU-2 to 11. . PU-12 and 13 were not evaluated because phase separation had occurred. Tables 3 and 4 show the evaluation results of adhesion, blocking resistance, and weather resistance.

[0054]

[Table 3]

[0055]

[Table 4]

In Tables 3 and 4, PP: a corona discharge treated stretched polypropylene film having a thickness of 15 μm PE: a corona discharge treated polyethylene film having a thickness of 15 μm EB: electron beam curable resin

[0057]

As described above, the polyurethane primer of the present invention has excellent adhesion between a polyolefin-based substrate and an electron beam-curable resin or an ultraviolet-curable resin. Further, the film coated with the primer of the present invention is excellent in blocking resistance at the time of winding and weather resistance. The primer of the present invention is suitable for building materials.

Claims (4)

[Claims] 1. A polyurethane primer used between an olefin film or sheet and an electron beam-curable or ultraviolet-curable surface coating agent comprises at least (A) an organic diisocyanate, (B) an acrylic polyol, A) a long-chain polyol other than an acrylic polyol, and (D) a polyurethane resin having a compound containing an ethylenically unsaturated bond and an active hydrogen group,
The polyurethane-based primer, wherein the content of the acrylic polyol (B) in the polyurethane resin is 20 to 80% by mass. 2. A polyurethane primer used between an olefin film or sheet and an electron beam-curable or ultraviolet-curable surface coating agent comprises at least (A) an organic diisocyanate, (B) an acrylic polyol, A) a polyurethane resin comprising, as constituents, a long-chain polyol other than an acrylic polyol, (D) a compound containing an ethylenically unsaturated bond and an active hydrogen group, and (E) a chain extender; The polyurethane-based primer, wherein the content of the polyol is 20 to 80% by mass. 3. The polyurethane-based primer according to claim 2, wherein (E) the chain extender is an alicyclic polyol and / or an alicyclic polyamine. 4. A polyurethane-based primer comprising 100 parts by mass of the polyurethane resin according to claim 1 and 1 to 50 parts by mass of a polyisocyanate curing agent.