US4336835A
Expired / Lapsed
US
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Production of wet-strength paper with aqueous solutions of cationic thermosetting resins
Assignee: Sumitomo Chemical Co Ltd
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Filing: 1981-04-14
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Granted: 1982-06-29
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Expires: 2001-04-14
Abstract
Abstract A durable aqueous solution of a thermosetting resin having a relatively high solid content which imparts a high degree of wet strength to paper, is produced by the reaction of an aliphatic dicarboxylic acid with a polyalkylenepolyamine to form a polyamidopolyamine, which is successively subjected to reaction with epichlorohydrin, the first reaction being carried out using a molar ratio of aliphatic dicarboxylic acid to polyalkylenepolyamine of 1:1.0 to 1.2 and continued until the viscosity at 25 DEG C. of 50% aqueous solution of resulting polyamidopolyamine reaches 400 to 1,000 cps, and the second reaction being carried out using epichlorohydrin in an amount of 1.6 to 1.7 moles per mole of the polyamide secondary amine and continued until the viscosity at 25 DEG C. of 15% aqueous solution of the resulting product reaches 30 to 150 cps.
Inventors
- 👤 Hisao Takagishi
- 👤 Norio Kondo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:03
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/02; C08G73/028; C08G73/0286; C08G69/00; C08G69/02; C08G69/48; D; D21; D21H; D21H17/00; D21H17/20; D21H17/33; D21H17/46; D21H17/54; D21H17/55; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31725; Y10T428/31779; Y10T428/31783
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
177 words
A process for producing wet-strength paper, which comprises applying to paper an aqueous solution of a thermosetting resin produced by a process consisting essentially of (i) heating an aliphatic dicarboxylic acid and a polyalkylenepolyamine to obtain a polyamidopolyamine, the molar ratio of the aliphatic dicarboxylic acid to the polyalkylenepolyamine being 1:1.0 to 1.2, and the heating being continued until the viscosity at 25° C. of a 50% aqueous solution of the resulting polyamidopolyamine reaches 400 to 1,000 cps, (ii) reacting the polyamidopolyamine with epichlorohydrin in an aqueous medium, the amount of epichlorohydrin being 1.6 to 1.7 moles per mole of the secondary amino group present in the polyamidopolyamine, the concentration of said reactants in the aqueous medium being 15 to 50% by weight, and the reaction being continued until the viscosity at 25° C. of a 15% aqueous solution of the reaction product reaches 30 to 150 cps, (iii) controlling the concentration of aqueous reaction product solution to 15 to 30% by weight, and (iv) adjusting the aqueous solution to pH 3 to 5 at 25° C.
Claim 2
Dependent Claim
177 words
A process for producing wet-strength paper, which comprises applying to paper an aqueous solution of a thermosetting resin produced by a process consisting essentially of (i) heating an aliphatic dicarboxylic acid and a polyalkylenepolyamine to obtain a polyamidopolyamine, the molar ratio of the aliphatic dicarboxylic acid to the polyalkylenepolyamine being 1:1.0 to 1.2, and the heating being continued until the viscosity at 25° C. of a 50% aqueous solution of the resulting polyamidopolyamine reaches 400 to 1,000 cps, (ii) reacting the polyamidopolyamine with epichlorohydrin in an aqueous medium, the amount of epichlorohydrin being 1.6 to 1.7 moles per mole of the secondary amino group present in the polyamidopolyamine, the concentration of said reactants in the aqueous medium being 15 to 50% by weight, and the reaction being continued until the viscosity at 25° C. of a 15% aqueous solution of the reaction product reaches 30 to 150 cps, (iii) controlling the concentration of aqueous reaction product solution to 15 to 30% by weight, and (iv) adjusting the aqueous solution to pH 3 to 5 at 25° C.
Claim 3
Dependent Claim
23 words
The process according to claim 1, wherein the aliphatic dicarboxylic acid is malonic acid, succinic acid, glutaric acid, adipic acid or sebacic acid.
Claim 4
Dependent Claim
15 words
The process according to claim 1, wherein the polyalkylenepolyamine is diethylenetriamine, triethylenetetramine, tetraethylenepentamine or iminobispropylamine.
Claim 5
Dependent Claim
27 words
The process according to claim 1, wherein the heating in the step (i) is carried out in the presence of a catalytic amount of a sulfonic acid.
Claim 6
Dependent Claim
18 words
The process according to claim 4, wherein the sulfonic acid is sulfuric acid, benzenesulfonic acid or p-toluenesulfonic acid.
Claim 7
Dependent Claim
24 words
The process according to claim 1, wherein the heating in the step (i) is carried out at a temperature of 100° to 250° C.
Claim 8
Dependent Claim
26 words
The process according to claim 1, wherein the reaction in the step (ii) is carried out at a temperature of about 30° to about 80° C.
Claim 9
Dependent Claim
9 words
Wet-strength paper produced by the process of claim 1.
Claim 10
Dependent Claim
178 words
A process for producing wet-strength paper, which comprises applying to paper an aqueous solution of a thermosetting resin produced by a process consisting essentially of (i) heating an aliphatic dicarboxylic acid and a polyalkylenepolyamine to obtain a polyamidopolyamine, the molar ratio of the aliphatic dicarboxylic acid to the polyalkylenepolyamine being 1:1.0 to 1.2, and the heating being continued until the viscosity at 25° C. of a 50% aqueous solution of the resulting polyamidopolyamine reaches 400 to 1,000 cps, (ii) reacting the polyamidopolyamine with epichlorohydrin in an aqueous medium, the amount of epichlorohydrin being 1.6 to 1.7 moles per mole of the secondary amino group present in the polyamidopolyamine, the concentration of said reactants in the aqueous medium being 15 to 50% by weight, and the reaction being continued until the viscosity at 25° C. of a 15% aqueous solution of the reaction product reaches 30 to 150 cps, (iii) adjusting the aqueous solution to pH 3 to 5 at 25° C., and (iv) controlling the concentration of the aqueous reaction product solution to 15 to 30% by weight.
Claim 11
Dependent Claim
178 words
A process for producing wet-strength paper, which comprises applying to paper an aqueous solution of a thermosetting resin produced by a process consisting essentially of (i) heating an aliphatic dicarboxylic acid and a polyalkylenepolyamine to obtain a polyamidopolyamine, the molar ratio of the aliphatic dicarboxylic acid to the polyalkylenepolyamine being 1:1.0 to 1.2, and the heating being continued until the viscosity at 25° C. of a 50% aqueous solution of the resulting polyamidopolyamine reaches 400 to 1,000 cps, (ii) reacting the polyamidopolyamine with epichlorohydrin in an aqueous medium, the amount of epichlorohydrin being 1.6 to 1.7 moles per mole of the secondary amino group present in the polyamidopolyamine, the concentration of said reactants in the aqueous medium being 15 to 50% by weight, and the reaction being continued until the viscosity at 25° C. of a 15% aqueous solution of the reaction product reaches 30 to 150 cps, (iii) adjusting the aqueous solution to pH 3 to 5 at 25° C., and (iv) controlling the concentration of the aqueous reaction product solution to 15 to 30% by weight.
Claim 12
Dependent Claim
23 words
The process according to claim 9, wherein the aliphatic dicarboxylic acid is malonic acid, succinic acid, glutaric acid, adipic acid or sebacic acid.
Claim 13
Dependent Claim
15 words
The process according to claim 9, wherein the polyalkylenepolyamine is diethylenetriamine, triethylenetetramine, tetraethylenepentamine or iminobispropylamine.
Claim 14
Dependent Claim
27 words
The process according to claim 9, wherein the heating in the step (i) is carried out in the presence of a catalytic amount of a sulfonic acid.
Claim 15
Dependent Claim
18 words
The process according to claim 9, wherein the sulfonic acid is sulfuric acid, benzenesulfonic acid or p-toluenesulfonic acid.
Claim 16
Dependent Claim
24 words
The process according to claim 9, wherein the heating in the step (i) is carried out at a temperature of 100° to 250° C.
Claim 17
Dependent Claim
26 words
The process according to claim 9, wherein the reaction in the step (ii) is carried out at a temperature of about 30° to about 80° C.
Claim 18
Dependent Claim
9 words
Wet-strength paper produced by the process of claim 9.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-06-28 | 1985-12-28 | 1986-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-28 | 1989-12-28 | 1990-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-28 | 1993-12-28 | 1994-06-29 | $7700.00 | Window Closed / Lapsed |