WO1998033845A1

WO1998033845A1 - Unsaturated polymer polyurethane structural adhesive

Info

Publication number: WO1998033845A1
Application number: PCT/US1998/001793
Authority: WO
Inventors: Daniel A. Chung
Original assignee: Ashland Inc.
Priority date: 1997-02-04
Filing date: 1998-01-30
Publication date: 1998-08-06
Also published as: JP2001503099A; EP0958319A4; BR9807155A; EP0958319A1; AU6138698A; CN1251600A; CA2279315A1

Abstract

This invention is a structural adhesive and a laminate of untreated substrates adhered together with a structural adhesive which combines a two part polyurethane adhesive with a two part free radical curing adhesive. The adhesive is especially useful in the manufacture of personal watercraft built to withstand rough waves and made of fiberglass reinforced plastic.

Description

UNSATURATED POLYMER POLYURETHANE STRUCTURAL ADHESIVE

This invention relates to adhesives useful on fiberglass reinforced polyester (FRP) substrates used to make personal watercraft which must withstand rough treatment by waves.

Background of The Invention

Commercially available polyurethane has been used to adhere FRP structural adhesives on personal watercraft substrates but only if the surface to be bonded is pretreated, such as by sanding or priming with a solvent before applying the adhesive to the substrate. As watercraft manufacturers become more aware of the labor intensity and the environmental problems caused by such surface treatments, new adhesives are needed to bond these structures together without any surface treatment.

Detailed Description of The Invention

Personal watercraft are made by hand laying glass mats or glass fibers on a mold or form. The glass is then bonded-together with a resin, usually unsaturated polyesters cured at room temperature by free radical chemistry

initiated by peroxides. Typically, such parts are cured in the open air, although sometimes they are compressed briefly to control thickness uniformity. In either process, air in the surrounding atmosphere inhibits the

-l- crosslinking reaction resulting in a partially uncured top surface. It is well known that such an inadequately cured surface is difficult to adhere without some surface treatment, such as a solvent wipe or sanding.

It was discovered that if the adhesive contains unsaturation functionality, hereafter referred to as an "unsaturated polymer", it can be cured by free radical chemistry initiated by peroxide and used to bond watercraft parts without any surface treatment. However, the unsaturated polymer / peroxide cured adhesive is very brittle, since there is no strength reinforcement in the adhesive such as the glass fibers used to build the watercraft itself. It was discovered that such peroxide cured adhesives can be toughened or flexibilized by a cocuring polyurethane adhesive.

In addition to adhesion, this very flexible unsaturated polymer / polyurethane adhesive for watercraft showed excellent sag resistance, fast green strength development and a tack free surface. Retention of adhesion was also demonstrated by exposing the bonds in 100% relative humidity

environment at 100°F (38°C) for eight weeks. Testing of bond strength after

such exposure typically showed greater than 230 psi.

Examples of unsaturated polymers for such adhesives include the same type of unsaturated polyesters used to construct watercraft as well as unsaturated polyurethanes. Typical unsaturated polyesters are the reaction product of a glycol and an unsaturated carboxylic acid or anhydride and

dicyclopentadiene or styrene. The unsaturated polyurethane is typically prepared by endcapping a polymeric polyol with a polyisocyanate to prepare a prepolymer. Then, the isocyanate end groups are converted to unsaturation by reaction of the isocyanate with the hydroxyl group of an unsaturated alcohol, such as hydroxylethyl acryiate or hydroxyethyl methacrylate (HEMA). U.S. Patents 4,480,079, 5,126,396 and 5,250,608 describe the preparation of unsaturated polyurethane.

To reduce the viscosity of the unsaturated polyurethane product, one commonly adds more isocyanate to the prepolymer to prepare a low molecular weight adduct of HEMA-capped polyisocyanate simultaneously with the prepolymer preparation step. Also very effective in viscosity reduction is the addition of low molecular weight reactive diluents such as styrene, acrylates or methacrylates. These diluents also cocure with the unsaturated polymer when exposed to a free radical initiator such as a peroxide. Alternatively, the prepolymer step of such unsaturated polyurethane may be bypassed by simply reacting HEMA, polyol and polyisocyanate in one step to form an unsaturated polyurethane.

A room temperature curing adhesive for bonding personal watercraft without surface preparation is formed by combining the unsaturated polymer with a polyurethane. Exemplary polyurethane adhesives are described in U.S. Patents 4,923,756, 5,002,806 and 5,548,056. Examples of such combination include 1 ) having polyisocyanate and peroxide as Part A and polyol/poiyamine and unsaturated polymer as Part B or 2) having polyol and

peroxide as Part A and polyisocyanate and unsaturated polymer as Part B.

Interpenetrating network structural adhesives are prepared by mixing Part A

and Part B using a propeller type mechanical mixer or a mix machine such as

Model 200 from EMC², Sterling Heights, Michigan. To facilitate room

temperature curing, a peroxide such as benzoyl peroxide to initiate free

radical formation at room temperature and conventional catalysts such as

tertiary amine, organotin, and organocobalt may be used.

Alternatively, since many commercial peroxides are available for the

initiation of peroxide formation above room temperature, a peroxide other than benzoyl peroxide may be used for the adhesives of this invention, if the

curing at elevated temperatures is desired. In such cases, the formulator has

the option of combining all the ingredients into a single mixture, instead of

Part A and Part B. When the adhesive is ready to be cured heat is applied to

initiate free radical formation and thus crosslinking.

Among the fiberglass reinforced polyester substrates useful in the practice of this invention are those hand layup and cold press substrates provided by Arctic Cat, Inc, Thief River Falls, MN (formerly known as Arctco) or Mercury Marine, Hartford, Wl. ^•" r The unsaturated polymer polyurethane adhesive of this invention is

made by combining a polyisocyanate, a component reactive toward polyisocyanate, an unsaturated polymer and a free radical initiator. Among

the polyisocyanates useful in this invention are: diphenylmethane diisocyanate, toluene diisocyanate,

1 ,4-phenylene diisocyanate,

3,3'-dimethoxy-4,4'-biphenyl diisocyanate, S.S'-dimethyM^'-diisocyanatobiphenyl,

3,3' dimethyl-4,4'-diisocyanato diphenyl methane, or their polymerized versions or mixtures thereof. The most preferred isocyanate in the practice of this invention is polymeric Rubinate 9310 available from ICI, Sterling Heights, Michigan or Isonate 143 L polyisocyanate from Dow Chemical, Midland, Michigan.

Alternatively, the polyisocyanate useful in this invention may also be derived from the reaction product of a polyisocyanate and a polyol of 1.8-6 functionality. The polyols useful for the preparation of such prepolymers may be 700 to 10,000 molecular weight polypropylene oxide ether diol, polyethylene oxide polypropylene oxide ether diol, polytetramethylene ether glycol, polythioether diol, polyester diol, polyepsilon caproiactone diol, polycarbonate diol, polybutadiene diol or mixtures of these diols. The preferred polyol is a polypropylene oxide ether diol of 1000 or 2000 molecular weight available from Olin Chemicals, New Haven, Connecticut as Poly G 20- 112 or Poly G 20-56, repectively.

The component selected to cure the polyisocyanate in the unsaturated polymer polyurethane adhesive of this invention includes the polyols used to make the prepolymer and polyamines. Other polyols include polyester and polyether polyols which have a functionality of 1.8 to 6.0 and a hydroxyl number from 100 to 1200. A hydroxyl number range of 200 to 700 and a functionality range of 3 to 5 are preferred. Suitable active hydrogen containing materials include diols, triols and tetrols, having primary, secondary and/or tertiary alcohol groups. Among the preferred polyether polyols are: Pluracol PeP 550 polyol, a propoxylated derivative of pentaerythritol having four secondary hydroxyl groups, a hydroxyl number of 450, and a molecular weight of 500 available from BASF Wyandotte Coφoration, Parsippany, N. J.; Arcol F3220, an ethoxylated / propoxylated derivative of glycerin having thee secondary hydroxyl groups, a hydroxyl number of 52 and a molecular weight of about 3200 available from ARCO Chemical Company, Newtown Square, PA; Fomrez ET3500, a propoxylated derivative of glycerin having three secondary hydroxyl groups, a hydroxyl number of 48 and a molecular weight of about 3500, available from Witco Corporation, Organic Division, Houston, Texas; Pluracol P-355 polyol, an ethoxylated/propoxylated derivative of ethylene diamine having about 80% of its hydroxyl groups as primary and having a hydroxyl number of 450, also available from BASF Wyandotte Corporation; Thanol R470X polyol, available from Texaco Chemical Co., Bellaire, Tex., a propoxylated derivative of diethanolamine with a functionality of about 4 and a hydroxy number of 500; Thanol SF-265 polyol, also available from Texaco Chemical Co., a propoxylated derivative of triethanolamine with a functionality of about 3 and a hydroxyl number of 600; Voranol 230-660 polyol, a polyether triol of 85.4 equivalent weight based on the propoxylation of glycerin, available from Dow Chemical Co., Midland, Mich.; and Dianol 2210 polyol, an ethoxylated derivative of bisphenol-A with a functionality of 2 and a hydroxyl number of 280, available from Akzo Chemie America, Chicago, III.

Among the numerous diamines useful for curing the unsaturated polymer polyurethane adhesive of this invention are the following aromatic diamines: toluene diamine

1 -methyl-3,5-diethyl-2,4-diaminobenzene

1-methyl-3,5-diethyl-2,6 diaminobenzene (also known as DETDA or diethyl toluene diamine) di(methylthio) toluene diamine I .S.S-triethyl-Σ.δ-diaminobenzene toluene diamine derivatives containing halogen groups, cyano groups, alkoxy, alkylthio, alkenyl or carbonylic moieties m-phenylene diamine p-phenylene diamine

4,4'-methylenedianiline 4,4'-diaminodiphenyl sulfone 2,6-diamino-pyridine 4,4'-methylene bis(3-chloroaniline) 4,4'-methylene bis(3-chloro-2,6-diethylaniiine)

4,4'-methylene bis (3-chloro-2,5-diethylaniline) 3,3'-di-isopropyl-4,4'-diaminodiphenylmethane 3,5,3', 5'-tetraethyl-4,4'-diaminodiphenylmethane propylene-di-4-aminobenzoate isobutyl 4-ch!oro-3,5-diaminobenzoate bis (2-aminophenyl) disulfide bis (4-aminophenyl) disulfide di (alkylated amino) benzene secondary diamine bis (alkylated aminophenyl) methane secondary diamine 3,3'-carbomethoxy-4,4'-diamino diphenylmethane and mixtures thereof. The most preferred diamine for the adhesive of this invention is diethyl toluene diamine (Ethacure 100, from Albemarle Corporation, Orangeburg, SC), which also contributes to the sag resistance of the adhesive beacause of its high reactivity. Another ingredient in the formulation of the adhesive of this invention is an optional catalyst to faciliate the crosslinking reaction of the adhesive between amines and isocyanates, and between polyols and isocyanates. Suitable tertiary amine catalysts include N, N', N"- dimethylaminopropylhexahydrotriazine (Polycat 41 ) and 1 ,4- diazabicyclooctane, and suitable organo metallic catalysts such as those derived from zinc, potassium, bismuth and tin including dibutylin dilaurate, dibutyltin diacetate, ferric acetyl acetonate, nickel acetylacetonate, dibutyltin dialkyl acid, stannous octoate, dibutyltin diiso-octyl mercapto acetate, dibutyl tin diisooctyl maleate, and mixtures of these catalysts. The preferred organo metallic catalyst is the dibutyltin diacetate known as DABCO T1 available from Air Products, Allentown, Pa. The preferred tertiary amine catalyst is dimethyl aniline.

Other optional ingredients in the formulation of the adhesive of this invention include thickening, coloring, odor control agents and drying agents. The preferred optional thickening agents are: aluminum silicates, carbon black, talcs (magnesium silicates), calcium carbonate, calcium silicates, barium sulfates, graphite, or mixtures of fillers. The preferred filler ingredient is Aerosil 200 or Aerosil R972 fumed silica from Degussa Inc., New York, N.Y.; and Cabosil TS 720 fumed silica from Cabot Corporation, Cab-O-Sil Division, Tuscola, IL.

Small amounts of other optional materials may also be added to the adhesive formulation. These include coloring agents, for example, Stantone HCCC. 6783 green coloring agent from Harwick Chemical Company, Akron, Ohio, which is a blend of C.I. Pigment Green #7 and C.I. Pigment Black #7 dispersed in a polyoxypropylene polyol at 17.8 parts of pigment to 82.2 parts polyol.

It maybe desirable also to use from 0.5 to 15.0 percent of a drying agent such as a Molecular Sieve powder of the 5 Angstrom size available from Union Carbide or anhydrous aluminum s^'ulfate powder from Geo Specialty Chemicals, Inc, Little Rock, Arkansas.

The customer combines Part A and Part B in the desired ratio, usually 1 weight part Part A is blended with 1-10 weight parts Part B. Unsaturated polymer polyurethane structural adhesives are prepared by mixing Part A and Part B typically using a mix machine Model 200 from EMC², Sterling Heights, Michigan. The adhesive is applied to the first substrate by conventional means. The second substrate is then laminated over the first adhesive coated substrate. The adhesive is typically cured at room temperature, although other energy sources such as microwave, radio frequency or dielectric energy or electromagnetic energy maybe used to accelerate the cure of the adhesive.

Crosspeel adhesion samples were prepared using room temperature cured hand layup fiberglass reinforced polyester plaques, prepared from dicyclopentadiene, vinyl esters, or the reaction product of unsaturated dicarboxylic acid and glycol. Representative types of theses substrates are the Arctco FRP or Arctco Cold Press or Mercury Marine FRP constructions used to manufacture personal watercrafts. A fiberglass reinforced polyester plaque was cut into 1 inch by 3 inch strips. Adhesive was applied onto the center 1 inch by 1 inch area with no surface pretreatment. A few glass beads of 30 mils diameter was spinkled onto the adhesive to control the bondline thickness when the center of a second 1 inch by 3 inch fiberglass polyester plaque was mated onto the first strip with the adhesive. After curing the adhesive at room temperature, the crosspeel samples were pulled on a Monsanto Tensometer 10 tester fitted with a jig to hold the four unadhered ends of the crosspeel samples. The upper strip of the crosspeel was pulled until it is separated from the bottom strip. Adhesion strength values over 600 psi were observed with failure occurring by tearing apart the cured polyester resin from the fiberglass used to reinforce the substrate. This is referred to in the industry as "fiber tear" or "FT" and is a very desirable result. The

performance of an adhesive is rated on the amount of fiber tear based on the percentage of the adhered one square inch. The data is recorded as pounds per square inch (psi) followed by a parenthesis which contains a first % of fiber tear and a second of cohesive failure. When the summation of the percentage values in the parenthesis does not equal to 100 the remainder is understood to be adhesive failure. Cohesive failure is designated to be a failure leaving adhesisve on both pieces of plaque forming the crosspeel adhesion sample. Adhesive failure is designated to be a failure with separation of the adhesive from the substrate without exposure of the giassfiber reinforcing the substrate. Green strength development of an adhesive is evaluated by testing adhesion crosspeel samples after they are cured at different intervals of time at room temperature, typically at 20 and 30 minutes. An adhesion strength of about 50 psi is considered adequate for handling the weight of personal watercraft parts in the production assembly line. Fiber tear accompanying failure of the crosspeel sample is considered superior performance of the adhesive.

The nature and advantage of this invention can be more readily seen and appreciated by reference to the following .representative examples, where all components are expressed in parts by weight (pbw). All patents mentioned herein are expressly incorporated by reference.

EXAMPLE 1 This example one describes the preparation of a polyisocyanate / peroxide Part A to be cured by a polyol / polyamine / unsaturated polymer Part B.

Formulation:

Polyisocyanate 4495

Rubinate 9310 polydiphenylmethane diisocyanate 11.92pbw Moisture scavenger Molecular Sieves 5A powder 0.18

Cabosil TS720 treated fumed silica 0.88

Luperco ATC 50% Benzoyl Peroxide 5.29

18.27

Procedure

Rubinate 9310 was charged into a 22-liter flask. With an efficient, high shearing stirrer and under a nitrogen blanket;. Molecular sieves 5A powder

was added, followed by Cabosil TS720. Then, Luperco ATC was added to the resulting very viscous mixture. Mixing of the peroxide was initiated by handmixing with a paddle. Final thorough mixing was achieved by low shearing with a mechanical mixer for 15 minutes. Degassing of the final mixture was initiated by slowly opening the vacuum line. When full vacuum was achieved the product was degassed for 30 minutes before discharge. The product was stored under a nitrogen blanket.

EXAMPLE 2

This example 2 describes the preparation of another polyisocyanate / peroxide Part A, a polyol is reacted with the polyisocyanate before the addition of peroxide.

Formulation:

Polyisocyanate 4627

PolyG 20-112 ethylene oxide capped polypropyline ether glycol (MW 1000) 50.00pbw

Moisture scavenger Molecular Sieves 5A powder 3.86

Rubinate 9310 polydiphenylmethane diisocyanate 158.40

Mistron RCS Talc 46.31

Aerosil R972 hydrophobic fumed silica 11.58

Luperco ATC 50% Benzoyl peroxide 115.78

385.93 Procedure

Polypropylene ether glycol (PPG) (MW 1000), PolyG 20-112 was dehydrated in a vessel at 100-105°C and at a vacuum of less than 1 mm Hg,

or until the moisture content was less than 0.05%. The dried PPG was

cooled to 85°C before adding Molecular Sieves 5A and Rubinate 9310.

Degassing was resumed and the polyol and polyisocyanate reacted at 85- 95°C for an hour or until the isocyanate content reached the theretical value

of 19.79%. The mixture was cooled to 50°C and the vacuum was broken. A

nitrogen blanket was introduced before the addition of Mistron RCS and then Aerosil R972. When the addition of the filler was complete Luperco ATC was

added. Mixing of the resulting viscous mixture was initiated by handmixing with a paddle. Final thorough mixing was achieved by low shearing with a mechanical mixer for 15 minutes. The final mixture was degassed. When full vacuum was achieved degassing was continued for 30 minutes before discharge. The product was stored under a nitrogen blanket.

EXAMPLE 3

This example 3 describes the preparation of an unsaturated polyurethane (UPU) to be blended with a polyol and/or a polyamine to form Part B.

Formulation: Unsaturated Polyurethane (UPU)

Methyl Methacrylate, MMA 48.0 pbw

Hydroquinone, HQ 0.008 p-Benzoquinone, BQ 0.008

Hydroxyethyl Methacrylate, HEMA 9.6

Rubinol F428 ethylene oxide capped triol (Hydroxyl No 28) 29.3

Rubinate M polydiphenylmethane diisocyanate 11.5

Dibutyl tin dilaurate 0.68

MMA 0.86

99.96

Procedure

MMA and HEMA were charged. Hydroquinone (HQ) and p- benzoquinone (BQ) were added and stirred until homogeneous. Rubinol F428, an ethylene oxide capped polyether triol with a hydroxyl number of 28 was charged. The moisture content was less than 600 ppm. Rubinate M was charged and stirring continued. Dibutyl tin dilaurate predissolved in MMA was charged. The reaction was stirred and continued for 90 minutes.

EXAMPLE 4

This example 4 describes the preparation of another unsaturated polymer similar to the unsaturated polyester (UPE) chemistry used to bind glass fibers

for the manufacture of watercraft.

Unsaturated Polyester UPE Diethylene glycol 467.2 pbw

Dipropylene glycol 31.1

Maleic anhydride 99.3

Isophthalic acid 536.3

Styrene 538.0

Monotertiary butyl hydroquinone 0.193

Methanol 0.772

Procedure

Diethylene glycol and dipropylene glycol were charged and heated to 140°C under an inert blanket. Maleic anhydride and isophthalic acid were added

and heat to 210°C. The reaction continued until a viscosity at 28% styrene of

13-15 stokes. Styrene and monotertiary butyl hydroquinnone dissolved in

methanol were added. The product was cooled to 170°C and discharged.

EXAMPLE 5

This example 5 describes the preparation of a polyol / polyamine /

unsaturated polymer Part B to cure a polyisocyanate such as Example 1

polyisocyanate 4495.

Curative 4600

PeP 550 Propoxylated pentaerythritol (Hydroxyl Number 450, MW 500) 2.67 pbw

ET 3500 Propoxylated glycerin (OH# 48, MW 3500)

10.98 Ethacure 100 Diethyltoluene diamine

2.72 Example 3 unsaturated polyurethane

43.59 Methyl methacrylate (MMA)

8.38 Diallyl Phthalate (DAP)

6.70

Cabosil TS720 treated fumed silica 7.54

Moisture scavenger Molecular Sieves 5A powder 0.42

StanTone 6783 green dye

0.17 Dimethyl aniline (DMA) 0.59

Dabco T1 Dibutyl tin diacetate

0.059

83.819 Procedure

PeP550, ET3500, Ethacure 100, Modar 839 and DAP were charged

and stirred to mix thoroughly. Half the required Cabosil TS720 was

added. When the mixture was still quite fluid Molecular Sieves 5A, StanTone

6783, DMA and Dabco T1 were added. Under a nitrogen blanket, finish

adding the remaining Cabosil TS720. When the filler was thoroughly wetted

and dispersed the mixture was degassed. When full vacuum was achieved

degassing continued for 20 minutes before discharge. The product was

stored under an air atmosphere.

EXAMPLE 6

This example 6 illustrates the adhesion performance of an unsaturated

polyurethane plus polyurethane hybrid adhesive 4606 by mixing

Polyisocyanate 4495 of Example 1 with Curative 4600 of Example 5. After

curing at room temperataure on Arctic Cat, Inc., Thief River Falls, MN 56701 ,

fiberglass reinforced polyester substrate or Arctic Cat, Inc. cold pressed FRP or Mercury Marine FRP, adhesion strength as high as 610 psi with 98% fiber tear was observed. The adhesive also possessed excellent sag resistance by showing no slump when dispensed on a vertical surface. It had a bondability time of 5.75 minutes and developed a strength of 127 psi after 30 minutes at room temperature. (Table 1 )

Table 1. Adhesion Performance of Acrylated Polyurethane / Polyurethane

EXAMPLE 7

This example 7 illustrates the adhesion performance of an unsaturated polyurethane and polyurethane prepolymer hybrid adhesive on FRP.

2. Performance of a Prepolymer / Acrylated Polyurethane / Polyurethane Hybrid Adhesive

EXAMPLE 8

This example 8 illustrates the adhesion performance of an unsaturated polyester, unsaturated polyurethane and polyurethane hybrid adhesive on FRP.

Table 3. Performance of a Unsaturated Polyester / Acrylated Polyurethane /

Polyurethane Hybrid Adhesive

Example 9

This example 9 illustrates the formulation of polyols with peroxide to form Part A and unsaturated polymer and polyisocyanate to form Part B.

Table 4. Performance of Polyol-Peroxide / Acrylated Polyurethane- Polyisocyanate Hybrid Adhesives.

^*Curative 4002 is prepared by reacting the polyols PolyTHF250 (275.00 pbw) and TMP (35.76 pbw) with Mondur MRS polyisocyanate (133.00) before the

addition of Luperco ATC (443.76 pbw).

Example 10 This example 10 illustrates the use of benzoylperoxide (BPO) / dimethylaniline (DMA) or methylethylketone peroxide (DDM9) / cobalt naphthenlate to cure unsaturated polymer and polyurethane hybrid adhesives.

Table 5. Peroxide Curing of Hybrid Adhesives

*OM Group, Inc., Outokumpu Chemicals. Mooney Chemicals Inc.

Vasset S.A. Cleveland, Ohio.

Example 11

This example 11 illustrates the use of diallyl phthalate (DAP) to achieve flexibility in unsaturated polymer / polyurethane hybrid adhesives. Ultimate elongation values as high as 85% as measured in the stress-strain test of the

neat adhesives were observed.

Table 6. Diallyl phthalate (DAP) as an Effective Promotor of Flexibility for Unsaturated Polymer / Polyurethane Hybrid Adhesives

^*Polytetramethylene ether glycol, MW 250.

Review of the Table 6 data shows that diallyl phthalate was very effective for promoting high ultimate elongation values of 59 to 85% for both

unsaturated polyurethane / polyurethane prepolymer and unsaturated polyurethane / polyisocyanate adhesives.

Example 11a

This example illustrates the use of an epoxy resin such as Epon 826 to achieve flexibility in unsaturated polymer / polyureaurethane hybrid adhesives. Ultimate elongation value of 63% as measured in the stress- strain test of the neat adhesive was observed.

Table 6a. Epoxy Resin as an Effective Promotor of Flexibility for Unsaturated Polymer / Polyurethane Hybrid Adhesives

*EPON 826 epoxy resin is the product of epichlorshydrin and bisphenol A available from Shell.

Example 12

This example 12 illustrates the humidity resistance of the unsaturated polymer / polyurethane hybrid adhesives. Tables 7, 8 and 9 show adhesives retaining as much as 100% of the adhesion to FRP after exposure to 100%

relative humidity at 100°F (38°C j for 4 and & weeks.

Table 7. Formulations of Unsaturated Polyurethane Polymer /Polyurethane Hybrid Adhesives.

Table 8. Humidity Resistance of Unsaturated Polyurethane Poiymer/Polyurethane Hybrid Adhesives from Table 7

-31-

-32-

m 2s Table 9. Humidity Resistance of Adhesive 4606 in Table 1, Example 6

Review of Tables 7, 8 and 9 reveals that some adhesives of this invention provide laminates having humidity resistance whether the adhesives are Part

A polyisocyanate plus unsaturated polyurethane.- Part B polyol plus peroxide or Part A polyisocyanate plus peroxide - Part B polyol plus unsaturated polyurethane.

Claims

I Claim:

1. A two component structural adhesive composition for substrates requiring no surface pretreatment and curable at ambient temperatures comprising either:

a) a first component mixture of polyisocyanate and peroxide and a second component mixture of polyol or polyamine or combinations thereof, and unsaturated polymer. or b) a first component mixture of polyisocyanate and unsaturated polymer, a second component mixture of polyol and peroxide.

2. The adhesive of claim 1 wherein said peroxide is benzoyl peroxide.

3. The adhesive of claim 1 further comprising diallyl phthalate.

4. The adhesive of Claim 1 wherein said polyisocyanate is polymeric methylene diphenyl polyisocyanate, said polyol is a mixture of propoxylated pentaerythritol and propoxylated glycerin, said polyamine is diethyl toluene diamine, and said unsaturated polymer comprises unsaturated polyurethane or unsaturated polyester or combinations thereof.

5. The adhesive of Claim 1 wherein said substrates are selected from the group of fiberglass reinforced plastic, metal and wood.

6. The adhesive of Claim 1 wherein said substrates are fiberglass reinforced plastic.

7. A laminate of two substrates having no surface pretreatment adhered together by the cured residue of a two component adhesive mixed before application to one of said substrates, said adhesive comprising polyisocyanate, polyol or polyamine or mixtures thereof, unsaturated polyurethane or unsaturated polyester or mixtures thereof, and peroxide.

8. The laminate of claim 7 wherein said polyisocyanate and said peroxide are provided in a first component mixture and said polyol or polyamine and said unsaturated polymer provided in a second component

mixture,

9. The laminate of claim 7 wherein said polyol and said peroxide are provided in a first component mixture and said polyisocyanate and said unsaturated polyurethane or said unsaturated polyester are provided in a second component mixture.

10. The laminate of claim 7 displaying, when disrupted, tearing of said fiber glass reinforced plastic substrate and continuing integrity of said

cured adhesive residue.

11. The laminate of Claim 7 wherein said polyisocyanate is polymeric methylene diphenyl polyisocyanate, said polyol is a mixture of propoxylated pentaerythritol and propoxylated glycerin, said polyamine is diethyl toluene diamine, and said unsaturated polymer comprises unsaturated polyurethane or unsaturated polyester or combinations thereof.

12. The laminate of Claim 7 wherein said substrates are selected from the group of fiberglass reinforced plastic, metal and wood.

13. The laminate of Claim 7 wherein substrates are fiberglass reinforced plastic.

14. The method of making a laminate of a first untreated substrate and a second substrate adhered together with a structural adhesive comprising a peroxide curable unsaturated polymer in combination with a polyurethane or polyureaurethane, such adhesive having room temperature curable property, variable open time, sag resistance on a vertical surface, tack free squeeze-out along the bondline, trimmable squeeze-out along the bondline, fast green strength development, at least 20% ultimate elongation, humidity resistance, and low temperature resistance, comprising the steps of applying to said first substrate an adhesive composition comprising a mixture of a first component a) polyisocyanate and peroxide and a second component b) unsaturated polymer and polyol or polyamine or mixtures thereof.

15. The method of claim 17 wherein the equivalent ratio of polyisocyanate: polyol plus polyamine is 0.8 to 1.8:1.

16. The method of claim 17 comprising 15 to 50 parts by weight of said first component and 50 to 85 parts by weight of said second component.

17. The method of claim 17 wherein said first component comprises polyisocyanate and unsaturated polymer and said second component comprises polyol and peroxide.

18. The method of Claim 17 wherein the equivalent ratio of polyisocyanate:polyol is 0.8 to 1.8:1.

19. The method of Claim 17 wherein said polyisocyanate is polymeric methylene diphenyl polyisocyanate, said polyol is a mixture of propoxylated pentaerylthritol and propoxylated glycerin, said polyamine is diethyl toluene diamine, and said unsaturated polymer comprises unsaturated polyurethane or unsaturated polyester or mixtures thereof.

20. The method of Claim 17 wherein said substrates are selected from the group of fiberglass reinforced plastic, metal and wood.

21. The method of Claim 17 wherein said substrates are fiberglass

reinforced plastic.

22. An adhesive composition for substrates requring no surface pretreatment comprising polyisocyanate, peroxide, polyol, unsaturated polymer, and optionally polyamine.

23. The adhesive of Claim 25 wherein said peroxide is tertiary butyl perbenzoate.

24. The adhesive of Claim 25 wherein said substrates are selected from the group of fiberglass reinforced plastic, metal and wood.

25. The adhesive of Claim 25 wherein said substrates are fiberglass

reinforced plastic.

26. The adhesive of Claim 1 further comprising epoxy resin.

27. The laminate of Claim 7 wherein said adhesive further comprises

epoxy resin.

28. The method of Claim 14 wherein said adhesive further comprises

epoxy resin.