US4410685A — Hydrolytically stable urea-formaldehyde resins an…

Claim 1

Independent Claim 96 words

A process for preparing a urea-formaldehyde base resin having a F/U mole ratio of 1.0:1-1.2:1, that is hydrolytically stable, which comprises adjusting an aqueous formaldehyde solution to a pH of from about 0.5 to about 2.5, slowly charging urea to said formaldehyde solution while maintaining the temperature of the solution in the range from about 50° to about 70° C., neutralizing the reaction mixture after attaining 2.9-3.1:1 mole ratio of formaldehyde to urea and a Gardner viscosity in the range of T+-V+ and then adding the final charge of urea to achieve the desired mole ratio.

Claim 2

Dependent Claim 96 words

A process for preparing a urea-formaldehyde base resin having a F/U mole ratio of 1.0:1-1.2:1, that is hydrolytically stable, which comprises adjusting an aqueous formaldehyde solution to a pH of from about 0.5 to about 2.5, slowly charging urea to said formaldehyde solution while maintaining the temperature of the solution in the range from about 50° to about 70° C., neutralizing the reaction mixture after attaining 2.9-3.1:1 mole ratio of formaldehyde to urea and a Gardner viscosity in the range of T+-V+ and then adding the final charge of urea to achieve the desired mole ratio.

Claim 3

Dependent Claim 12 words

The process of claim 1, wherein the mole ratio is substantially 1:1.

Claim 4

Dependent Claim 36 words

The process of claim 1 or 2 wherein the pH of the formaldehyde solution is adjusted to 0.5-2.5 using formic acid, hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, or a mixture of two or more of these.

Claim 5

Dependent Claim 11 words

The process of claim 3 wherein said acid is sulfuric acid.

Claim 6

Dependent Claim 17 words

The process of claim 4 wherein the pH of the formaldehyde solution is adjusted to about 1.0.

Claim 7

Dependent Claim 26 words

The process of claim 1 or 2 wherein the reaction mixture is neutralized to a pH of 7.2-7.5 before the final charge of urea is added.

Claim 8

Dependent Claim 21 words

The process of claim 6 wherein sodium hydroxide and/or triethanolamine, or a mixture thereof, is used for neutralizing the reaction mixture.

Claim 9

Dependent Claim 25 words

The process of claim 1 or 2 wherein the reaction mixture is stirred for at least 30 minutes after adding the final charge of urea.

Claim 10

Dependent Claim 134 words

A process for preparing a urea-formaldehyde base resin having a F/U mole ratio of 1.0:1-1.2:1, and that is hydrolytically stable, which comprises adjusting an aqueous formaldehyde solution containing from about 49.8% to about 50.2% formaldehyde to a pH of 0.5-2.5 using formic acid, hydrochloric acid, sulfuric acid or p-toluenesulfonic acid, or a mixture of two or more of them, slowly charging urea to said formaldehyde solution while maintaining the temperature of the solution at 50°-70° C. until a 2.9-3.0 mole ratio of formaldehyde to urea is obtained, neutralizing the reaction mixture to a pH of 7.2-7.5 after obtaining a Gardner viscosity in the range of T+-V+, using sodium hydroxide and/or triethanolamine, and adding the final charge of urea while maintaining the pH at 7.2-7.5 and stirring for at least long enough to permit equilibration.

Claim 11

Dependent Claim 134 words

A process for preparing a urea-formaldehyde base resin having a F/U mole ratio of 1.0:1-1.2:1, and that is hydrolytically stable, which comprises adjusting an aqueous formaldehyde solution containing from about 49.8% to about 50.2% formaldehyde to a pH of 0.5-2.5 using formic acid, hydrochloric acid, sulfuric acid or p-toluenesulfonic acid, or a mixture of two or more of them, slowly charging urea to said formaldehyde solution while maintaining the temperature of the solution at 50°-70° C. until a 2.9-3.0 mole ratio of formaldehyde to urea is obtained, neutralizing the reaction mixture to a pH of 7.2-7.5 after obtaining a Gardner viscosity in the range of T+-V+, using sodium hydroxide and/or triethanolamine, and adding the final charge of urea while maintaining the pH at 7.2-7.5 and stirring for at least long enough to permit equilibration.

Claim 12

Dependent Claim 12 words

The process of claim 9 wherein the mole ratio is substantially 1:1.

Claim 13

Dependent Claim 25 words

A urea-formaldehyde base resin having a mole ratio of 1.0:1-1.2:1 and being hydrolytically stable which is prepared by the process of claim 1 or 9.

Claim 14

Dependent Claim 14 words

The urea-formaldehyde base resin of claim 11 wherein the mole ratio is substantially 1:1.

Claim 15

Dependent Claim 36 words

A urea-formaldehyde liquid base resin comprising urea and formaldehyde in a mole ratio of 1.0:1-1.2:1, said resin containing essentially no free formaldehyde and said resin when cured containing substantially more methylene groups than methylene ether groups.

Claim 16

Dependent Claim 36 words

A urea-formaldehyde liquid base resin comprising urea and formaldehyde in a mole ratio of 1.0:1-1.2:1, said resin containing essentially no free formaldehyde and said resin when cured containing substantially more methylene groups than methylene ether groups.

Claim 17

Dependent Claim 15 words

The urea-formaldehyde liquid base resin of claim 13 wherein the mole ratio is substantially 1:1.

Claim 18

Dependent Claim 17 words

The liquid base resin of claim 14 comprising 24.89 weight percent formaldehyde and 49.78 weight percent urea.

Claim 19

Dependent Claim 27 words

The resin of claim 15 which further comprises 0.06 weight percent sulfuric acid, 0.05 weight percent sodium hydroxide, and 0.33 weight percent triethanolamine, the balance comprising water.

Claim 20

Dependent Claim 62 words

The resin of claim 13, 14, 15 or 16 having a solids content from about 61% to about 65%, a specific gravity of 1.250 to 1.270, a Brookfield viscosity from about 100 cps to about 400 cps as measured at 25° C. on an RVF viscometer, #1 spindle, at 20 rpm, and having a refractive index from about 1.4600 to about 1.4700.

Claim 21

Dependent Claim 21 words

A resin according to claim 13 that when cured contains more than twice as many methylene groups as methylene ether groups.

Claim 22

Dependent Claim 15 words

A resin according to claim 13 or 14 that is essentially free of methylol groups.

Claim 23

Dependent Claim 21 words

The resin of claim 13 or 14 which when cured contains at least 2.5 methylene groups per 1 methylene ether group.

Claim 24

Dependent Claim 32 words

A urea-formaldehyde liquid base resin comprising 24.89 weight percent formaldehyde, 49.78 weight percent urea, 0.06 weight percent sulfuric acid, 0.05 weight percent sodium hydroxide, 0.33 weight percent triethanolamine, and the balance, water.

Claim 25

Dependent Claim 32 words

A urea-formaldehyde liquid base resin comprising 24.89 weight percent formaldehyde, 49.78 weight percent urea, 0.06 weight percent sulfuric acid, 0.05 weight percent sodium hydroxide, 0.33 weight percent triethanolamine, and the balance, water.

Claim 26

Dependent Claim 36 words

A process for curing a resin prepared in accordance with claim 1 or 2 comprising heating said resin at a pH in the range from about 7.2 to about 7.5 at 135° C. to 193° C.

Claim 27

Dependent Claim 32 words

A process in accordance with claim 22 including, as a preliminary step prior to heat curing, the step of mixing the liquid base resin with a cross-linking agent, then heating to cure.

Claim 28

Dependent Claim 30 words

A process according to claim 22 including a preliminary step, prior to heat curing the resin, of mixing the liquid base resin with an acid-reacting catalyst, then heating to cure.

Claim 29

Dependent Claim 34 words

A process according to claim 23 wherein the cross-linking reagent contains at least two functional groups of the formula ##STR8## per molecule where R is an alkyl group of from 1 to 24 carbons.

Claim 30

Dependent Claim 12 words

A process according to claim 25 wherein the cross-linking agent is trimethoxymethylmelamine.

Claim 31

Dependent Claim 11 words

The process of claim 25 wherein the cross-linking agent is hexamethoxymethylmelamine.

Claim 32

Dependent Claim 26 words

The process of claim 25 wherein the cross-linking agent is a methoxylated urea formaldehyde resin having the formula ##STR9## wherein n is an integer from 1-6.

Claim 33

Dependent Claim 40 words

A curable liquid base resin formulation that can be heat cured to form a cross-linked structure comprising in combination a liquid base resin produced according to claim 1, 2, 9 or 10 together with a cross-linking agent for the resin.

Claim 34

Dependent Claim 12 words

The resin formulation of claim 29 in combination with an external catalyst.

Claim 35

Dependent Claim 26 words

The formulation of claim 29 that, upon curing, has a cross-linked structure containing essentially no free formaldehyde and substantially more methylene groups than methylene ether groups.

Claim 36

Dependent Claim 18 words

The cured resin of claim 31 containing more than twice as many methylene groups as methylene ether groups.

Claim 37

Dependent Claim 13 words

The cured resin of claim 32 that is essentially free of methylol groups.

Claim 38

Dependent Claim 56 words

A curable resin formulation containing a urea formaldehyde liquid base resin prepared according to claim 1, 2, 9 or 10, in combination with a cross-linking agent, each molecule of which has at least two groups reactive with a member of the group consisting of amine, carbonyl, and hydroxy groups, which are present in the liquid resin.

Claim 39

Dependent Claim 37 words

The resin formulation of claim 34 wherein the cross-linking agent contains at least two functional groups of the formula --N--CH.sub.2 --O--R per molecule where R is an alkyl or hydroxy alkyl group of 1 to 24 carbons.

Claim 40

Dependent Claim 14 words

A cured, cross-linked resin obtained by heat curing a formulation according to claim 29.

Claim 41

Dependent Claim 14 words

A cured, cross-linked resin obtained by heat curing a formulation according to claim 30.

Claim 42

Dependent Claim 14 words

A cured, cross-linked resin obtained by heat curing a formulation according to claim 31.

Claim 43

Dependent Claim 14 words

A cured, cross-linked resin obtained by heat curing a formulation according to claim 34.

Claim 44

Dependent Claim 14 words

A cured, cross-linked resin obtained by heat curing a formulation according to claim 35.

Claim 45

Dependent Claim 102 words

A process for preparing a amino-formaldehyde base resin having a F/U mole ratio of 1.0:1-1.2:1, and that is hydrolytically stable, which comprises adjusting an aqueous formaldehyde solution to a pH of from about 0.5 to about 2.5, slowly charging an amino compound to said formaldehyde solution while maintaining the temperature of the solution at 50°-70° C. until a 2.9-3.0 mole ratio of formaldehyde to the compound is obtained, neutralizing the reaction mixture to a pH of 7.2-7.5 after obtaining a Gardner viscosity in the range of T+-V+, and adding the final charge of the amino compound to achieve the desired mole ratio.

Claim 46

Dependent Claim 102 words

A process for preparing a amino-formaldehyde base resin having a F/U mole ratio of 1.0:1-1.2:1, and that is hydrolytically stable, which comprises adjusting an aqueous formaldehyde solution to a pH of from about 0.5 to about 2.5, slowly charging an amino compound to said formaldehyde solution while maintaining the temperature of the solution at 50°-70° C. until a 2.9-3.0 mole ratio of formaldehyde to the compound is obtained, neutralizing the reaction mixture to a pH of 7.2-7.5 after obtaining a Gardner viscosity in the range of T+-V+, and adding the final charge of the amino compound to achieve the desired mole ratio.

Claim 47

Dependent Claim 12 words

The process of claim 41 wherein said resin is a urea-melamine-formaldehyde resin.

Claim 48

Dependent Claim 38 words

An amino-formaldehyde liquid base resin comprising an amino compound and formaldehyde in a mole ratio of 1.0:1-1.2:1, said resin containing essentially no free formaldehyde and said resin when cured containing substantially more methylene groups than methylene ether groups.

Claim 49

Dependent Claim 38 words

An amino-formaldehyde liquid base resin comprising an amino compound and formaldehyde in a mole ratio of 1.0:1-1.2:1, said resin containing essentially no free formaldehyde and said resin when cured containing substantially more methylene groups than methylene ether groups.

Claim 50

Dependent Claim 14 words

The resin of claim 43 wherein amino is a mixture of urea and melamine.

Claim 51

Dependent Claim 38 words

A curable liquid base resin formulation that can be heat cured to form a cross-linked structure comprising in combination a liquid base resin produced according to claim 41 or 42 together with a cross-linking agent for the resin.

Claim 52

Dependent Claim 54 words

A curable resin formulation containing a urea formaldehyde liquid base resin prepared according to claim 41 or 42, in combination with a cross-linking agent, each molecule of which has at least two groups reactive with a member or the group consisting of amine, carbonyl, and hydroxy groups, which are present in the liquid resin.

Claim 53

Dependent Claim 14 words

A cured, cross-linked resin obtained by heat curing a formulation according to claim 46.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1986-10-17	1987-04-18	1987-10-18	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1990-10-17	1991-04-18	1991-10-18	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1994-10-17	1995-04-18	1995-10-18	$7700.00	Window Closed / Lapsed

Hydrolytically stable urea-formaldehyde resins and process for manufacturing them

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