JPS5836118B2 - Method of impregnating polyurethane polymers into permeable materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a new and advantageous process for improving the properties of certain permeable materials, such as paper, by impregnation with urethane polymers.

For example, impregnation of such paper significantly improves its dry and wet tensile strength and lamination failure resistance while maintaining its flexibility, thus making it suitable for packing, applied abrasives, artificial leather, Shoe lining, Lily liner for adhesive,
A product is obtained which is useful for many purposes including duct tape supports, particularly pressure sensitive adhesive tape supports.

The traditional method of impregnating paper for the above-mentioned applications consists of saturating it with latex or solutions of natural or synthetic rubber, but special types of rubber are used, and the adhesion of the rubber to the paper is extremely difficult. If the latex or solution dries in the paper due to insufficiency, the rubber will seep to the surface unless special measures are used to coagulate the rubber in the pores of the paper.

At best, higher adhesion is required than with the inventive method, and the wet strength and resistance to lamination, high temperatures and solvents are still poor.

Furthermore, the invention allows extensive control over the properties of the impregnated material.

This invention relates to paper and other permeable materials (hereinafter sometimes referred to as
called the "substrate".

) with a reactive or terminal incyanate group (−
It consists in being impregnated with a special type of polyurethane polymer solution containing (N=C=0).

Extremely large (high molecular weight) polymers are suitable as coating materials, but if they are too large, they will not completely penetrate into the substrate, and if the polymer is too low molecular weight, the product will It has been found to be too stiff, ie, lacks flexibility.

However, in the present invention, if the polymer is appropriately sized and contains reactive, i.e., terminal, incyanate groups, these groups can react with the hydroxyl groups of the paper to form urethane bonds. It has been revealed that this is because of the strong adhesion to paper.

Such fixation is possible on any substrate containing "active" hydrogen, and the presence of active hydrogen in the substrate can be determined by the Zelevitinoff method [Berichte 40. 2
023/1907); 41, 2236 (1908): Kohler, Journal of the American Chemical Society 49. 3138 (1927)], a cellulose-based sheet such as cellulose, cellulose ester, cellulose ether, etc. is used as the substrate.

The production of polyurethane polymers by the reaction of organic incyanates and their use in producing hard, abrasion-resistant coatings is described, for example, in Ameriga Patent No. 3.0 1 2,9.
87, and some of the chemical properties and general applications of polyurethane polymers are shown in the following documents:

"Polyurethane"; B. Koichi and Dombro, Reinhold Publishing Company New York, New York (1957) "Chemistry of Organic Isocyanates"; Chemical Review 43, 203-18 (194)
8) "Urethane plastic"; Industrial Engineering Chemicals, 48, 1383-91 However, in this invention, a polyurethane polymer is used,
and the discovery of a type of method that can be used to substantially uniformly impregnate and thereby substantially improve the properties of certain permeable materials such as those already mentioned.

For example, masking tapes typically use paper supports, which are inexpensive and can be treated to better suit the intended use by being saturated or impregnated to at least partially fill the pores. This is because it is wet.

Since adhesives are often applied in solvent solutions and the paints and lacquers that are sprayed onto their surfaces often contain solvents, the impregnated material must be solvent resistant.

The support must also be strong in the wet state to withstand fusing with water-based or latex paints (the wet strength of untreated paper is next to nil).

The impregnation must be able to withstand the high temperatures in the drying oven (rubber is not very resistant).

Finally, the support must be resistant to delamination and tearing so that the tape can be cleanly removed from its adhesion surface, even when subjected to the considerable forces required to remove strong stickies ( Of course, the level of adhesion of materials has in the past had to be limited by the failure resistance of the support).

The following procedure was used to use the impregnated paper according to the invention as a pressure-sensitive adhesive tape support.

For example, a thin IJ IJ-spray paint can be applied (dissolved in a suitable solvent which is later volatilized) to one side of this impregnated paper strip (ordinary pressure-sensitive adhesives will adhere firmly to the product according to the invention). However, it has now been found that it can be used as a leasing paint, backing or support, especially if a smooth paper is used as the substrate).

However, if necessary or desirable, IJ-based paints consisting of certain vinyl resins such as vinyl stearate, maleic anhydride, acrylic anhydride or mixtures thereof can be used.

On the other side of the strip, a thin binder or fixing paint is conventionally applied (applied in the form of a water emulsion and subsequently dried) in order to firmly adhere the adhesive film to the support. ).

Such tie paints are, for example, composed of emulsions or dispersions of neoprene or butadiene-styrene rubber and adhesive resins, stabilized with ammonium caseinide.

The dried binder paint is then applied with a pressure-sensitive adhesive consisting of a mixture of natural or synthetic rubber with tacky resins, softeners, antioxidants and fillers (the solvent is later removed by drying). in solution or by squeezing rollers)
.

The adhesive may also contain a proportion of butadiene styrene rubber and/or a phenolic resin and/or a small amount of a rubber hardener to harden the adhesive, especially when it is used at higher temperatures.

Urethane polymers are produced by the reaction of polyfunctional active hydrogen-containing organic compounds (mainly, for example, polyhydroxy compounds, ie polyols) and organic polyisocyanates.

The following examples illustrate, but do not limit, my methods and products.

Example 1 Polyether with a molecular weight of 1500} IJall 230 pounds (104K) (manufactured by Union Carbide Chemicals Company, New York, NY)
Niax Triol LHT 1 1 2), 2500 molecular weight polyether triol 58 lb (26.3 Kp) (a product of the same company, N
iax Triol LHT 6 7 ) and commercially available tolylene diisocyanate (containing 80% by weight of the 2,4 isomer and 20% by weight of the 2,6 isomer, hereinafter referred to as JTDIJ).

), 113 pounds (51.3 Ky) of heptane and 264 pounds (1
20K}).

This solution was prepared in a jacketed mixer at approximately 180%
Heated to 82-93°C for approximately 1 hour, then cooled and heated to 80°F (26.7°C) for 16 hours.
Time was saved.

At this point, analysis (see, eg, Dombro, supra, p. 171) determined that substantially all of the OH groups in the triol had reacted with the innoanate.

Three pounds (1.36 Kp) of stannath octoate (manufactured by Metal & Thermite Corporation, Carter Soto, NJ, known as Catalyst T-9) were mixed into the solution.

(To reduce costs, the triol has a low acid value of about 100 lbs (45.3 K) at the beginning of the procedure, about 25 wt φ of the prepolymer. The weight in milligrams of KOH equivalent to acid.

) of the resin, preferably less than about 4, and additional isocyanate corresponding to the active hydrogen content, if any, in the resin.

Suitable resins include, for example, NevilleResin L
Terpene resins or coumaron-indene resins obtained by polymerizing unsaturated petroleum hydrocarbon residues such as .

Otherwise, neutral or slightly acidic solid fillers such as silicate (e.g., Santocel, manufactured by Monsanto Chemical Company, St. Louis, MT), non-hydrophilic aluminum silicate or lamp black can be used. It is also possible to add up to about 25% by weight of the polymer.

Of course, the use of such resins or filler fillers sacrifices some properties of the final product.

) The sheet of paper is passed through the solution from the rolls and then passed from the press rolls through a hot air oven to remove excess solution and prepare the final impregnated paper minus the solvent, which is about 50% more by weight. In other words, the inside of the dryer was heated to an initial temperature of about 125'F (5
1.7°C) to a final temperature of about 350'F (177°C).

Total time in the oven was 7 to 3 minutes.

Toward the end of the drying process, after most of the solvent has evaporated, steam may be added to decompose the remaining incyanate groups to the extent that they do not solidify and remain on the paper, but in general, heating is not appropriate. There is no need for it, and the final product is substantially non-tacky.

The products exhibited good flexibility, significantly increased wet and dry strength, increased lamination failure resistance and good solvent and temperature resistance.

Example 2 Molecular weight 3000} Riol (Niax TriolL)
G 5 6 ) with TDI at 200'F (93
．． 4° C.) for 2 hours.

The reaction was carried out in a 50% by weight solution of toluene.

The solution was kept at 80'F (26.7C) for 24 hours.
No significant viscosity change was observed.

One part by weight of stannous octoate was then added to the total weight of the prepolymer and the untreated paper was saturated with this solution as in Example 1.

The final paper is flexible, non-tacky, has a 45% increase in weight ratio, and has a lamination resistance of 6 to 40 per inch of width.
oz (67 to 446.9 per c/n. width), dry tensile strength from 9 to 27 lb/in (1.6 to 4.82X), and wet tensile strength from 0 to 18 lb/in. inch (3.2% from O).

Example 3 Prepolymer is Niax Triol LG 5 6
Instead of, propylene oxide and 1,2, with a molecular weight of 1500,
6-hexanetriol (Niax Triol LH
It was made analogously to Example 2 using an adduct with T112) and reacting with a ratio of 3 moles of TDI to 1 mole of adduct.

Paper was treated as in Example 1 with a 45% by weight toluene solution of this prepolymer.

The final dry paper is non-tacky, has a 49 factor increase in weight, and has a lamination resistance of 6 to 45 oz/in (
67 to 500 g/. L), dry tensile strength from 9 to 29 lb/in (1.6 to 5.18%), and wet tensile strength from O to 19 lb/in (
0 to 3.4%).

Example 4 The procedure of Example 3 was followed, substituting glycerin for the adduct.

The product was extremely hard.

Example 5 Acid f hypropylene and dipropylene glycol with a molecular weight of 2000 (Niax Diol PPG 2 0 2 5
) was reacted with 2 moles of TDI in a 50 weight cup of toluene solution as described above.

The FC catalyst was added as described above and the paper was treated with this solution as described above.

The adhesion rate was 40.

Laminate fracture resistance from 6 to 40 oz/in (67 to 446'/), dry tensile strength from 9 to 27 (1.6 to 4.82X), and wet tensile strength from 0 to 18 lb/ inch (0 to 3.2X).

Example 6 The prepolymer was composed of a diol (Niax) with a molecular weight of 2000.
Diol PPG2025) 114 pounds (51.8K
9), a triol with a molecular weight of 4400 (Niax Tri
ol LHT4 2) 690 pounds (313K
y ), 431 pounds (1
95 Kp) (average molecular weight of the mixture is approximately 3300) and 200 pounds TDI (90.8 Kp), made in a 40 wt. toluene solution as described above.

Paper was treated with this solution and the catalyst was as described above.

Laminate fracture resistance ranges from 6 to 45 oz/in (67 to 500 kX) and dry tensile strength ranges from 9 to 33 (1
．． 6 to 5.9%) and wet tensile strength increased from 0 to 19 lb/in (0 to 3.6%).

The adhesion rate was 60%.

Example 7 The prepolymer was a triol (Nia
x Triol LHT4 2) 4 4 lbs (2
0 Kp), a diol with a molecular weight of 600 (Carbo
wax600, manufactured by Union Carbide Chemical Company) 5 pounds (2.27Kp), polymerized unsaturated petroleum hydrocarbon residue (Neville
Resin LX1050) 10 pounds (4.54K
p) and TDI 8.7 lbs (3.94 KF?) were made in a 60% toluene solution as described above.

Paper treated with this solution (catalyst as described above) was 55%
adhesion rates of 6 to 35 oz/in (67 to 390 g/.L), dry tensile strengths of 9 to 25 (1.6 to 4.46X), and wet tensile strength of 9 to 25 (1.6 to 4.46 Strength ranges from 0 to 18 pounds per inch (O to 3.
2%).

Example 8 A prepolymer was made as described above using 1 mole of a 4400 molecular weight triol and 3 moles of TDI in a 50 volume solution of toluene.

Paper treated as described above with this solution was extremely sticky and flexible.

The above tensile strength measurements were 1 inch (2.54 crr
L) in the usual way for a strip of width, e.g.
Tensile strength was determined using a Scott Tester in the dry state or on strips soaked in water at room temperature in the case of wet tensile strength.

Laminate failure resistance is determined by firmly adhering a ``tensile strip'' to both ends of a 1 inch (2.54 crIL) strip, initiating a tear, and measuring the force required to sustain the tear. .

Examples 1, 2, 3, 5, 6 and 7 demonstrate highly favorable product properties when appropriate molecular weight preols and preol mixtures are used according to the process of this invention.

Example 4 shows that the use of polyhydroxy compounds of too low a molecular weight results in products that are too hard.

This is the only unsatisfactory embodiment cited above.

If the polymer has too low a molecular weight and therefore the crosslinks are too close together, a close-networked and therefore stiff, inflexible polymer is obtained.

On the other hand, if the polymer is of too high a molecular weight,
and/or if it is too highly cross-linked, its toluene solubility will be low and it will not penetrate well into the pores of the paper.

When there are too few reactive groups remaining in the prepolymer,
The adhesion to the paper may not be sufficient.

Example 8 shows unsatisfactory results using too high a molecular weight polyol, in which case there is too little crosslinking to yield a satisfactory product.

Less than 2 equivalents of isocyanate (optionally U″NCO
”.

) reacts with 1 equivalent of hydroxyl groups (less than 2 mol of NCO for 1 mol of diol or less than 3 mol of NGO for 1 mol of triol), chain extension occurs, which is the immediate Considering the purpose, the formation of prepolymer is not preferable.

This is because too few NGO groups produce molecules that are too large, making it impossible to obtain good fixation on paper.
Also, because there are too few cross-links (wide network final polymer), a strongly bonded final product is not obtained.

On the other hand, if more than about 27 equivalents of NCO are reacted per equivalent of OHI in the polyol (1), and the reaction proceeds too much, too large molecules of prepolymer are formed as well.

This is because in this case the excess NCO groups, unencumbered by early reactivity, also react with the less reactive active hydrogens of the urethane groups to form allophanate esters.

The most preferred procedure is to use polyisocyanates containing NCO groups of different reactivity.

For example, in 2.4-4 lylene diisocyanate, the NCO group at position 2 is sterically hindered by the adjacent methyl group.

Furthermore, these two NCO groups have sufficiently different reactivities to allow the larger reactive group to be used in the production of the prepolymer to a large extent, and the prepolymer to or does not react rapidly when kept at room temperature when stored for use, whereas after the catalyst is added and applied to the support, the applied or impregnated network is heated. In some cases, it has been discovered that rather than reacting rapidly, it is actually important to retain less reactive groups.

The less reactive NCO is thus present to bind the polymer to the active hydrogen in the support.

However, due to the high cost of the pure 2,4 isomer of TDI, we have discovered that in practice a compromise can be made that allows for substantially more effective applications with different reactivities.

Obviously others believe that in a prepolymer like the one I use, there is enough difference in reactivity to avoid significant viscosity increases in the prepolymer solution during its use. I did not understand that it was possible to have time through this procedure.

Such different reactivities of different NCO groups are also present in other polyisocyanates, such as ethylbenzene, xylene, bitrylene, methyldiphenylmethane, dimethyldiphenylmethane, disnisidine, and certain other isomeric diisocyanates.

Furthermore, the presence of other adjacent groups such as chlorine increases the reactivity of the NCO group.

However, at present, 2.4-H diisocyanate is the cheapest and most readily available, and the difference in reactivity between the NCO groups in the 2 and 4 positions is such that the type I use is I have shown that it is sufficient to have practical value in reacting with polyols.

Furthermore, I made further improvements to the impregnation process as follows.

Although my procedure described above has been very useful, there is still a limit to the longevity of the prepolymer solution, and there are occasional complaints about a slight undesirable hardness in the final impregnated paper.

I again used the same polyol and a stoichiometric amount of TDI from 80 to 100% relative to the OH equivalent (90
%) make a prepolymer.

The polyol and TDI are reacted at 100° C. for about 4 hours, and analysis confirms that no free NGO groups remain in the prepolymer.

Prepolymers made in this way have extremely long lifetimes and can often be stored for several weeks without increasing viscosity.

The prepolymer is then dissolved in toluene or a mixture of volatile aromatic and aliphatic solvents such as toluene and pentane to form a solution having a solids content of about 50% by weight.

Additionally, the ratio of the total equivalents of 1 to 6% of the stannous octoate catalyst by weight of the prepolymer, 10 to 100% of the weight of the stannous octoate, triethylamine, and the total equivalents of NCO:OH added to the final mixture is 1:1. from 1.5
: Add an amount of bisphenol adduct of methylene bis(4-phenyl isocyanate) to 1.

The mixture is extremely stable at room temperature.

The paper is then impregnated as described above, but with final solvent removal and curing at 300 to 320'F (149 to 160C) in as little as 30 seconds, providing excellent wet and dry strength and lamination. A product with uniform flexibility and fracture resistance is obtained.

If the final ratio of NCO:OH is less than 1:1, the prepolymer becomes dilute as it ages.

If it exceeds 1.5:1, the final impregnated paper will be too hard.

An example of my improvement method is as follows.

Example 9 20 pounds (9.07 KF!) of triol from Example 1 and 3 pounds of TDI (1,59 Kp) were heated at 100°C.
Allow time to react.

The product is dissolved in 30 pounds (13.6 Kp) of toluene.

To this solution, the above-mentioned bisphenol adduct of methylene-bis(4-phenyl isocyanate) or diphenylmethane-4,4l-diisocyanate 1-! - lb (6802 g) and 540 grams of Nutanus octoate catalyst and 54 grams of triethylamine are added.

This mixture is applied to paper as described above and heated at 300-320° C. (149-160° C.) for about 30 seconds.

The product is similar to that of Examples 2 and 3, but more flexible.

The prepolymer of Example 9 is preferably one or a mixture of tolylene diisocyanate isomers, including isomeric tolylene, bitrylene, diphenylmethane, dimethyldiphenylmethane, phenylene, triphenylmethane, hexamethylene, diphenylxenylene, It should be noted that the scales may be prepared using either xenylene, dichloroxenylene, dianisidine diisocyanate or dianidine triisocyanate.

Other polyols and mixtures thereof can be used in the procedure of Example 1) as well as in my earlier method described above.

Instead of phenolic adducts, organic polyisocyanates of the enol form of acetoacetate, acetomalonate, acetylacetone, penzoylacetone and acetylacetaldehyde can be used.

Furthermore, a dimer of 2,4-1-lylene diisocyanate can also be used.

These isocyanates are classified as inocyanate precursors or inocyanate generators (see Dombro, supra, pp. 26, 27, 28).

Phenol adduct is NCO in the presence of active catalyst
approximately 300 to 320'F (1
49 to 160° C.), whereas other adducts can be used at lower temperatures.

For example, the adduct of acetomalonate is approximately 260
Can be used at 'F (127°C).

In place of the polyols already mentioned, liquid hydroxide elastomers can be used, typical examples of which are as follows.

(1) Styrene-butadiene copolymer, styrene 15 to 20φ (preferably 20φ), hydroxyl value 42, trans 60 Hiroshi cis (1-4) 20 ratio, vinyl (1-2) 2
Viscosity at 30°C: 295 poise, 7.6 poise
+r:/9j・.

7 (0.91 KV/l) Iodine value 335; (2) Acrylonitrile-butadiene copolymer, acrylonitrile 10 to 20% (preferably 15%), hydroxyl group 39, trans 60, cis (1-4) 20% ,
Vinyl (1-2) 20 parts, viscosity 500 poise at 30°C, 7.7 lb/gal (0.92”q),
Iodine value 355; (3) Polybutadiene, hydroxyl value 45
, viscosity at 30° C. 200 poise, 7.5 lb/gal (0.99 t), iodine number 355, trans 60, cis(1-4) 20, vinyl(1-2) 20.

The hydroxyl value is preferably the one listed above, but it can vary from 20 to 60.

The trans, cis and vinyl proportions vary from 57 to 63, 19 to 21 and 19 to 21, respectively.

Viscosity is plus, minus 5% and iodine value is plus,
Each can change by -5%.

These hydroxide elastomers can be used in any mixing ratio with the above-mentioned polyol.

The catalyst for the procedures of Examples 1-8 was that of Brittain & Gemeinhardt (U.S. Pat. No. 3,397).
Any stannous or stannic tin-based catalyst can be used.

(1) Stannath octoate; (2) Stannath oleate; (3) catalyst (1) or (2) mixed with a tertiary amine; (4) 1 to 22 carbon atoms per molecule. (5) Catalyst (4) mixed with a tertiary amine; (6) Hostetler and Cox's stannic salt (U.S. Pat. No. 3,3
9 2, 1 2 8), such as dibutyltin dilaurate and other organic acid stannic salts; (7) Hostetler
Stanus Octoate (U.S. Pat. No. 3,398,106); (8) Stanus Neodecanoate.

However, stannous octoate or stannous neodecanate are preferred in these procedures.

This is because they give rapid curing, and even more rapid curing is obtained when a tertiary amine is added in an amount of 10 to 100% of the weight of the listed stannic or stannous tin catalyst. It is from.

Instead of tertiary amines, it is also possible to use primary or secondary amines, provided that sufficient incyanate is present to react with the active hydrogen.

The stannous and stannic tin-based catalysts listed above are
Although the method of Example 9 can be used if sufficient time and high temperature are used during curing, these tin-based catalysts are It is desirable to use a tertiary amine in an amount of 10 to 100 kg of the weight of the tertiary amine.

As a result, the impregnated material and the support do not have to be exposed to too high a temperature for too long, and the whole process is also speeded up from an economic point of view.

In this case, primary amines or secondary amines can also be used instead of tertiary amines, if incyanate is additionally used to react with the active hydrogens of the primary and secondary amine groups.
Can be used.

The use of stannous tin-based catalysts in combination with tertiary amines was demonstrated by Brittain and Gemeinhardt (see cited above).

However, here the tertiary amine has synergistic catalytic activity with the listed stannic tin-based catalysts, and furthermore, the primary and niamines have synergistic catalysis with both the stannous and stannic tin-based catalysts. It was revealed that it has a catalytic effect.

Particularly effective stannic tin-based catalysts in this regard are dibutyltin dilaurate, dibutyltin diacetate, dioctyltin diacetate, and dibutyltin maleate.

These mixtures of stannous and stannic tin-based catalysts with primary, secondary or tertiary amines can be used in my procedure with stable incyanate precursors or adducts or without amines. Allows for complete curing in about a few seconds compared to the use of just a few of the most active tin catalysts.

I have shown that the proportion of amine to tin catalyst may vary from 10 to 100% of the tin catalyst weight of stannous or stannic, but 10% is preferred and the proportion of tin catalyst that I use is The polyurethane polymer weight ranges from 1 to 6 yen.

Other catalysts that can be used, although less active, are lead naphthenate, cobalt naphthenate, phenylmercuric acetate, and bismuth naphthenate, and, as mentioned above, amines ranging from 10 to 100% of the catalyst weight. is available.

The amine alone exhibits little catalytic activity compared to the tin-based catalyst alone, and the combination of the tin-based catalyst and the amine exhibits much more activity than the sum of the activities of both the tin-based catalyst and the amine catalyst. , and thus exhibits a remarkable synergistic effect.

Tertiary amines suitable for use in combination with tin-based catalysts are trimethylamine, triethylamine, triprobylamine and tributylamine (triethylamine is preferred), N-methylmorpholine, N-ethylmorpholine, triethylenediamine, and others.

Perhaps the use of an amine will be necessary to impart a slight alkalinity to the impregnating solution.

If heating for more than 3 to 4 minutes is required for final curing, my processing method becomes expensive and undesirable, and if the heating temperature is 320'F (160'C) or higher, It should be noted that when the heating time exceeds 1 minute, the quality of the product begins to deteriorate.

Thus, as a practical matter, in the process illustrated by Examples 1-8, catalysts at least as active as dibutyltin dilaurate, preferably stannous octoate and stannous neodecanoate, or even better, combined with these catalysts, can be used. from 10 to over 100 of the weight of said amine.

When the isocyanate precursor is used as in Example 9, at least cyphtyltin dilaurate, dibutyltin diacetate, dioctyltin diacetate, dibutyltin maleate, stannath octoate and stannath neodecanoate are used. , 10 to 1 of its weight
It is recognized that it is advisable to use catalysts whose activity is obtained by mixing up to 0.00% of amines (tertiary amines as mentioned above are preferred).

Not only will a catalyst that is too inert slow down the process and be costly, but the increased time at high temperatures required for curing, as discussed above, can also lead to a reduction in product quality.

In general, prepolymers suitable for my intended use are soluble in toluene (as opposed to those for coatings) and do not require strong solvents such as esters, ketones, and polyfunctional solvents.

In practice, this prepolymer can absorb benzene, toluene, xylene, and mixtures thereof, as well as their aromatic solvents, from volatile liquid aliphatic, cycloaliphatic, and naphthenic hydrocarbons, of which heptane is the most useful)
It is soluble even when diluted to 30% by weight.

Although other solvents other than those used in the examples and those mentioned above are also suitable (e.g. monomethyl ether, monoethyl ether or monobutyl ether of ethylene glycol, acetate ester, ethyl acetate, ethers and ketones such as methyl ethyl ketone). ), the solvent is
It must be substantially inert in that it does not react with incyanate groups or polyols.

However, toluene or its mixtures with up to 30 parts by weight of hebutane are generally preferred because of their low cost and moderate volatility.

The solvent should have a normal boiling point below about 175°C (preferably 120°C).
).

The prepolymer concentration in the impregnation solution is approximately 20 to 80 wt φ
The polymer may vary up to 50%, usually about 40 to 50%, but even pure polymers can be used if they are in liquid form.

The proportion of polyurethane polymer in the final product can vary from about 20 to 80 parts of the initial substrate weight as desired.

In general, the present invention describes the use of polyhydroxy polyesters or a proportion of vegetable oils (e.g., castor ) can also be used.

However, polyesters are typically more expensive and tend to produce a somewhat less flexible end product, and castor oil has a lower level of reactivity with isocyanates.

Ethylene oxide or propylene oxide adducts of polyols are relatively inexpensive and, when chosen as described herein, are very satisfactory.

The polyol used should be of molecular weight in the range of about 400 to 4000, with an average molecular weight of between about 800 and about 3500 (preferably between 1000 and 3200).

Therefore, if a 400 molecular weight polyol is used, it should be thoroughly mixed with a higher molecular weight polyol so that the average molecular weight of the mixture is at least about 800 (of course 3
(not exceeding 500).

Similarly, if a 4400 molecular weight polyol is used, it should be thoroughly mixed with a lower molecular weight polyol to bring the mixture to an average molecular weight of at least 3500 (of course about 8
00)).

The most suitable prepolymer for my intended use is completely soluble in toluene containing up to about 30 weight φ of hebutane.

These solubility characteristics characterize my prepolymers and distinguish them from the polyurethane polymers used by others.

For use as a pressure sensitive adhesive tape support, the prepolymer impregnated and dried paper contains about 40 to 80% solid impregnant by total weight.

The present invention can be implemented in the following manner.

L In the claimed method, step (2)
The catalyst selected in is characterized by an activity at least as great as stannous octoate.

2. In the claimed method, said catalyst selected in step (2) is one of the listed stannic catalysts and one of the listed tertiary tin catalysts ranging from 10 to 100 tin catalysts listed therein. A method consisting of mixing with one of the amines.

3. In the permeable substrate containing active hydrogen, 20 to 80% by weight of the urethane prepolymer product is fixed by urethane bonds; , dimethyldiphenylmethane, and dianisidine, and a polyol having a ratio of incyanate equivalents to hydroxyl equivalents of 1.8 to 2.5. wherein at least substantially all of the larger isocyanate groups are reacted, but not all of the less reactive inocyanate groups, and the polyol has a molecular weight in the range of about 800 to about 3,500. and a mixture of polyols having a molecular weight of about 400 to about 4,400, the average molecular weight of which is selected from about 800 to about 3,500;
The prepolymer is affixed to the substrate by urethane bonds at the active hydrogen sites, and the isocyanate groups account for 1 to 6 of the weight of the prepolymer of at least one catalyst selected from the following types: a permeable substrate which has been completely reacted in the presence of (a) a stannous salt of an organic acid having from 1 to 22 carbon atoms per molecule; (b) dibutyltin dilaurate, dibutyltin diacetate, dioctyl; tin diacetate and dibutyltin maleate, and (
C) A tertiary amine selected from trimethylamine, triethylamine, triprobylamine, tributylamine, N-methylmorpholine, N-ethylmorpholine and triethylenediamine is added to the catalysts of (a) and (b) according to the catalyst weight. A mixture of 10 to 100% of

4. 3. The permeable substrate of item 3 above, wherein the catalyst contained therein is characterized by an activity at least as great as nutana octoate.

5. In the polyurethane polymer for impregnated paper, the viscosity of the polymer does not increase rapidly when placed at room temperature in the presence of a stannous octoate urethane catalyst of 1 to 6 parts of the polymer weight. , is soluble in toluene to at least 10% by weight;
Polyols with molecular weights ranging up to 00 and about 40
An incyanate whose reactivity with said polyol is substantially different from a polyol selected from a mixture of polyols having a molecular weight ranging from 0 to about 4,400 and whose average molecular weight ranges from about 800 to about 3,500. substantially all of the greater reactivity of a polyisocyanate containing incyanate groups, wherein the polyisocyanate has a ratio of incyanate groups to hydroxyl groups of the polyol of 1.8 to 2. 5 and at least one polyisocyanate selected from the polyisocyanates of tolylene polyisocyanate and ethylbenzene, xylene, bitrylene, methyldiphenylmethane, dimethyldiphenylmethane, and dianisidine; The hydroxyl groups of the polyurethane polymer are largely unreactive with the more reactive incyanate groups.

6. In the product of paragraph 3 above, an extender is added to the weight ratio of the prepolymer up to about 25%, said extender comprising a hydrocarbon resin having an acid number of less than about 4 and finely separated neutral and slightly acidic additives. Permeable substrates selected from the types of active solid fillers.

7. A pressure-sensitive adhesive tape comprising the product of item 3 above as a supporting material, wherein the permeable substrate is paper on one side of which a pressure-sensitive cleaning agent is applied.

8. In the method described in the claims, the step (3)
), wherein the inert solvent is toluene.

9. In the method described in the claims, the step (3)
), wherein the inert solvent is toluene containing hebutane in a weight ratio of up to 30φ.

10. A method comprising the steps of substantially uniformly depositing and immobilizing a polyurethane polymer in a permeable substrate containing active hydrogen: (1) a polyol having a molecular weight ranging from about 800 to about 3,500; A mixture of polyols having a molecular weight in the range of about 400 to about 4,400, the average molecular weight of which is in the range of about 800 to about 3,500, and a ratio of isocyanate equivalents to hydroxyl equivalents of the polyol is 0.
．． 8 to 1.0 tolylene diisocyanate,
Reacting until substantially all isocyanate groups have reacted to produce a prepolymer.

(2) Dissolving the product of step (1) in toluene to make a 20-80% by weight solution.

(3) Add 1 of the weight of the prepolymer to the product of step (2).
Adding at least one catalyst selected from the following types having a diameter of 1 to 6 φ.

(a) stannous salts of organic acids having from 1 to 22 carbon atoms per molecule; (b) dibutyltin dilaurate, dibutyltin diacetate, dioctyltin diacetate and dibutyltin maleate; and (C)
, (a) and (b), at least one tertiary amine selected from the group consisting of trimethylamine, triethylamine, triprobylamine, tributylamine, N-methylmorpholine, N-ethylmorpholine and triethylenediamine, 1 to 1oo of catalyst weight
% mixed.

0) Adding sufficient isocyanate precursor to the product of step (3) such that the ratio of total isocyanate equivalents to total hydroxyl equivalents is from 1:1 to 1.5:1.

In this case, the isocyanate precursor is a bisphenol adduct of methylene bis(4-phenyl isocyanate), an organic polyisocyanate adduct of enol-type acetoacetate, acetomalonate, acetylacetone, penzoylacetone, and acetylacetaldehyde, and 2.4-} It is at least one selected from the types of dimers of lylene diisocyanate.

(5) Applying the product of step (4) to the substrate such that the weight of the prepolymer is between 20 and 80 g.

(6) heating the product of step (5) at a temperature and time sufficient to volatilize the toluene and react substantially all incyanate groups of the precursor;

11. In the method described in paragraph 10 above, step (1)
The proportion of the catalyst in step (3) is 0.9, and the catalyst of step (3) contains 10 to 100% of its weight in stannous octoate.
of tertiary amine, the precursor of step (4) is a bisphenol adduct of methylene bis(4-phenyl isocyanate), and the temperature and time of step (6) are respectively between 300 and 3
20"F (149-160C) and 30 seconds.

12. In the method according to item 11 above, the catalyst is added to stannous neodecanoate in an amount of 10 to 1 of its weight.
00% tertiary amine addition method.

13. In the method described in item 11, the catalyst is added to dibutyltin dilaurate in an amount of lO to z of its weight.
A method with the addition of oo% tertiary amine.

14. The method according to item 10 above, wherein the substrate is paper.

15. The method according to item 11 above, wherein the substrate is paper.

16. The method according to item 12 above, wherein the substrate is paper.

17. The method according to item 13 above, wherein the substrate is paper.

18. tolylene diisocyanate and about 800 to about 3
Polyols with molecular weights ranging up to 500 and about 4
A mixture of polyols having a molecular weight ranging from 0.00 to about 4,400, the average molecular weight of which is from about 800 to about 3,500.
A polyurethane polymer consisting of a prepolymer reaction product with a polyol selected from the range from the prepolymer contains substantially no unreacted isocyanate groups, and the polyurethane polymer further contains a reaction product of a phenol adduct of methylene bis(4-phenyl isocyanate) with the prepolymer. and the paper has a ratio of total isocyanate equivalents to total hydroxyl equivalents of 1:1 to 1.5.
The adduct is present in the range of 1 to 1, and the impregnated paper contains 10 to 1 of its weight in stannous octoate.
An impregnated paper containing from 1 to 6 parts of the weight of said prepolymer a catalyst with the addition of oo% triethylamine.

19. The product according to item 18 above, in which stannath neodecanoate is substituted for the stannath octoate.

20. The product according to item 18 above, wherein dibutyltin dilaurate is substituted for the stannous octoate.

21. In the method described in Section 10 of the above, step (3)
The catalyst contains 10% of its weight in stannous octoate.
at least as active as a mixture of triethylamine.

22. In the method according to the claims, the poly
d--A styrene-butadiene copolymer containing styrene of 15 to 20 φ, 10 to 20%
The elastomer is substituted with an acrylonitrile-butadiene copolymer containing acrylonitrile of (14) and a method containing 19 to 21 pieces of vinyl (1-2).

23. In the method described in the claims, the polyol contains the hydroxide elastomer of Item 22 above.
and 1oo%.

24. The method according to item 1 above, wherein the polyol is replaced with the hydroxide elastomer according to item 22 above.

25. The method according to item 1 above, wherein the polyol is replaced with a mixture of the polyol and the hydroxide elastomer according to item 22 above, mixed with 100% O.

26. The product according to item 3 above, in which the polyol is replaced with the hydroxide elastomer according to item 22 above.

27. The product according to item 3 above, in which the polyol is replaced with a mixture of the polyol and the hydroxide elastomer according to item 22 above in an amount of between 100% and O.

28. 27. A product according to item 26 above, in which said catalyst is replaced by a catalyst characterized by an activity at least as great as that of stannous octoate.

29. 27. A product according to item 27 above, in which the catalyst is replaced by a catalyst characterized by an activity at least as great as that of stannous octoate.

Claims (1)

[Scope of Claims] 1 (1) Containing isocyanate groups of substantially different reactivity and consisting of tolylene diisocyanate and polyisocyanates of ethylbenzene, xylene, bitlylenemethyldiphenylmethane, dimethyldiphenylmethane and dianisidine; A mixture of an organic aromatic polyisocyanate comprising at least one polyisocyanate selected from the group consisting of a polyol having a molecular weight ranging from about 800 to about 3,500 and a polyol having a molecular weight ranging from about 400 to about 4,400. and a polyol selected from the group consisting of those having an average molecular weight of about 800 to about 3,500, in a range of 1.8 to 2.5 equivalents of isocyanate groups per equivalent of hydroxyl group, and substantially all of the polyols are (2) producing an isocyanate-terminated polymer by reacting up to and not exceeding the point at which the hydroxyl groups of the hydroxyl groups react with substantially all of the more reactive isocyanate groups; ) containing (a) a stannous salt of an organic acid having from 1 to 22 carbon atoms per molecule;
(b) dibutyltin dilaurate, dibutyltin diacetate, dioctyltin diacetate and dibutyltin maleate, (C), (a) and (b), respectively, trimethylamine triethylamine triprobylamine tributylamine, N-methylmorpholine, N-ethyl 10 to 1 tertiary amine selected from the group consisting of morpholine and triethylenediamine
from about 1 to about 6 weight percent of at least one catalyst selected from the group consisting of catalysts mixed to 0.00 weight φ; and (3) dissolved in a substantially inert solvent having a boiling point of less than about 175°C. The cellulosic sheet is coated with the solution of 20 to 30 parts by weight of the herbal product from step (2) so as to substantially uniformly impregnate the entire surface, and the final solvent-free sheet is reduced to 20 to 30 parts by weight of its original weight. and (4) heating the product of step (3) to evaporate the solvent and remove the terminal incyanate groups so that they substantially remain. A method for substantially uniformly adhering and fixing a polyurethane polymer to a cellulose sheet by a chemical reaction, the method comprising reacting with active hydrogen of the cellulose sheet so as to prevent the polyurethane polymer from forming.