# US 5,700,353 A · Paper strengthened with solubilized collagen and method

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- Number: US 5,700,353 A
- Document ID: US5700353A
- Status: Granted
- Kind: A
- Application number: 08/477,856
- Filed: 1995-06-07
- Granted: 1997-12-23
- Earliest claimed: 1993-06-16
- Assignees: Ranpak Corp.
- Inventors: Kenneth E. Hughes; David C. Masterson; David J. Fink; Barbara A. Metz; Gordon E. Pickett; Paul M. Gemmer; Richard S. Brody
- Web page: https://patentgrep.com/patent/US5700353A

## CPC

- C07K 14/78: Connective tissue peptides, e.g. collagen, elastin, laminin, fibronectin, vitronectin or cold insoluble globulin [CIG]
- D21H 17/22: Proteins
- A61K 38/00: Medicinal preparations containing peptides (peptides containing beta-lactam rings A61K31/00; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, A61K31/00; ergot alkaloids of the cyclic peptide type A61K31/48; containing macromolecular compounds having statistically distributed amino acid units A61K31/74; medicinal preparations containing antigens or antibodies A61K39/00; medicinal preparations characterised by the non-active ingredients, e.g. peptides as drug carriers, A61K47/00)
- D21H 11/14: Secondary fibres (working-up waste paper D21C5/02)
- D21H 21/18: Reinforcing agents
- C07K: PEPTIDES (peptides in foodstuffs A23; obtaining protein compositions for foodstuffs, working-up proteins for foodstuffs A23J; preparations for medicinal purposes A61K; peptides containing beta-lactam rings C07D; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, C07D; ergot alkaloids of the cyclic peptide type C07D519/02; macromolecular compounds having statistically distributed amino acid units in their molecules, i.e. when the preparation does not provide for a specific; but for a random sequence of the amino acid units, homopolyamides and block copolyamides derived from amino acids C08G69/00; macromolecular products derived from proteins C08H1/00; preparation of glue or gelatine C09H; single cell proteins, enzymes C12N; genetic engineering processes for obtaining peptides C12N15/00; compositions for measuring or testing processes involving enzymes C12Q; investigation or analysis of biological material G01N33/00)
- D21H: PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)

## Abstract

A method for making a collagen strengthened cellulosic sheet by providing a cellulosic pulp slurry; adding solubilized collagen to the pulp slurry, and mixing for a time effective for interaction of the cellulosic pulp slurry and solubilized collagen; forming the interacted cellulosic pulp slurry and solubilized collagen into a sheet; and drying the sheet; also, a method for using solubilized collagen for strengthening paper by mixing the solubilized collagen with a cellulosic pulp slurry; and making a cellulosic pulp product from the mixture and drying.

## Claims

### Claim 1

A paper product comprising soluble collagen, said product being formed by a process comprising the steps of:
a. reacting insoluble collagen with a proteolytic enzyme to produce a solution including soluble collagen having a number average weight of at least 300,000 daltons:
b. withdrawing the soluble collagen as product; and
c. using said soluble collagen in a paper-making process.

### Claim 2 (depends on 1)

A product as set forth in claim 1, wherein said insoluble collagen is provided as an aqueous ground slurry.

### Claim 3 (depends on 2)

A product as set forth in claim 2, wherein said process for forming said product further comprises adjusting the water or solid content of said slurry whereby said insoluble collagen is at a concentration that promotes a substantially maximum concentration and a maximum molecular weight of said soluble collagen in said product.

### Claim 4 (depends on 2)

A product as set forth in claim 2, wherein said process for forming said product further comprises adjusting the pH of said slurry to obtain activity for a proteolytic enzyme, prior to reacting said insoluble collagen with said proteolytic enzyme.

### Claim 5 (depends on 1)

A product as set forth in claim 1, wherein said process for forming said product further comprises controlling said reaction of Step a to obtain a high degree of conversion of insoluble collagen to soluble collagen and to maximize the molecular weight of said soluble collagen.

### Claim 6 (depends on 5)

A product as set forth in claim 5, wherein said process for forming said product further comprises simultaneously measuring the concentration of soluble collagen and the molecular weight of said soluble collagen, whereby said reaction is complete when said molecular weight and said concentration are substantially maximized.

### Claim 7 (depends on 1)

A product as set forth in claim 1, whereby said reaction of Step a of said process for forming said product is at a temperature, T, and a time, t, effective for forming a solution of soluble collagen from said insoluble collagen.

### Claim 8 (depends on 1)

A product as set forth in claim 1, wherein said process for forming said product further comprises mixing the soluble collagen of Step b with a cellulosic pulp slurry.

### Claim 9 (depends on 8)

A product as set forth in claim 8, wherein said cellulosic pulp slurry is prepared by a method comprising:
a. mixing cellulosic material selected from the group consisting of virgin paper pulp, broke, reclaimed newsprint, reclaimed carton container, or a mixture thereof, with a solution comprising water, or water and caustic; and
b. pulping said mixture until a cellulosic pulp slurry is formed having a consistency of about 3 wt % to about 6 wt % based on dry pulp solids.

### Claim 10 (depends on 9)

A product as set forth in claim 9, wherein said method for preparing said cellulosic pulp slurry further comprises diluting said cellulosic pulp slurry of Step b to a consistency of about 1 wt % to about 3 wt % based on dry pulp solids and adjusting pH to about 3.5 to about 7.0, prior to mixing with said soluble collagen.

### Claim 11 (depends on 8)

A product as set forth in claim 8, wherein said mixing of said process for forming said product is at a shear rate and a time effective for interaction of said dilute pulp slurry and said soluble collagen, whereby at least a substantial portion of said soluble collagen is bound to said paper pulp to form a collagen/pulp slurry.

### Claim 12 (depends on 11)

A product as set forth in claim 11, wherein said collagen/pulp slurry is diluted to between about 0.1 dry wt % and 1 dry wt % consistency.

### Claim 13 (depends on 13)

A product as set forth in claim 13, wherein said process for forming said product further comprises using said diluted collagen/pulp slurry to form a sheet and drying said sheet.

### Claim 14

A collagen strengthened cellulosic product, wherein said product is formed by a process comprising:
a. mixing a cellulosic material selected from the group consisting of virgin paper pulp, broke, reclaimed newsprint, reclaimed carton container, or a mixture thereof with a solution comprising water, or water and NaOH, and mechanically pulping until a pulp slurry is formed having a consistency of about 3 wt % to about 6 wt % based on dry pulp solids;
b. diluting said pulp slurry to a consistency of about 1 wt % to about 3 wt % based on dry pulp solids and adjusting pH to about 3.5 to about 7.0;
c. providing an aqueous ground slurry of insoluble collagen;
d. adjusting the water or solid content of said wet ground slurry whereby said insoluble collagen is at a concentration that promotes substantially maximum soluble collagen concentration and molecular weight in a final product;
e. adjusting the pH of said slurry from Step d to obtain activity for a proteolytic enzyme added in Step f;
f. adding said proteolytic enzyme to said pH adjusted slurry and reacting at a temperature, T, and for a time, t, effective for forming a solution including soluble collagen from said insoluble collagen;
g. controlling said reaction to obtain a high degree of soluble collagen and a molecular weight of said soluble collagen where the collagen is capable of binding with cellulosic pulp, by simultaneously measuring the concentration of soluble collagen and the molecular weight of said soluble collagen, whereby said reaction is complete when said molecular weight and said concentration are substantially maximized;
h. withdrawing at least some of the solution of Step f containing soluble collagen as product;
i. adding said soluble collagen of Step h comprising between about 0.1 dry wt % to about 2 dry wt % soluble collagen (based on dry weight of cellulosic material) to said diluted pulp slurry, and mixing at a shear rate and a time effective for interaction of said diluted pulp slurry solids and soluble collagen, whereby at least a portion of said soluble collagen is bound to said pulp to form a collagen-pulp slurry;
j. diluting said collagen-pulp slurry to between about 0.1 dry wt % and about 1 dry wt % consistency;
k. forming said collagen-pulp slurry into a cellulosic product of desired shape; and
m. drying said product.

### Claim 15 (depends on 14)

A product as set forth in claim 14, wherein said product is a cellulosic sheet.

### Claim 16

A collagen strengthened cellulosic product, wherein said product is formed by a process comprising:
a. providing an aqueous ground slurry of insoluble collagen and adjusting the pH of said slurry to obtain activity for a proteolytic enzyme added in Step b;
b. adding said proteolytic enzyme to said pH adjusted slurry;
c. reacting the slurry and enzyme of Step b at a temperature, T, and for a time, t, effective for forming a solution increased in soluble collagen;
d. withdrawing at least some of the solution of Step c containing soluble collagen as product;
e. mixing a cellulosic material selected from the group consisting of virgin paper pulp, broke, reclaimed newsprint, reclaimed carton container, or a mixture thereof with a solution comprising water, or water and caustic, and mechanically pulping until a pulp slurry is formed having a consistency of about 3 to about 6 wt % based on dry pulp solids;
f. diluting said pulp slurry to a consistency of about 1 to about 3 wt % based on dry pulp solids and adjusting pH to about 3.5 to about 7.0;
g. adding said soluble collagen from Step c to said diluted pulp slurry in an amount from between about 0.1 to about 2 dry wt % soluble collagen (based on dry weight of cellulosic material), and mixing at a shear rate and a time effective for interaction of said diluted pulp slurry solids and soluble collagen, whereby at least a substantial portion of said soluble collagen is bound to said paper pulp to form a collagen-pulp slurry;
h. diluting said collagen-pulp slurry to between about 0.1 dry wt % and about 1 dry wt % consistency; and
i. forming said collagen-pulp slurry into a cellulosic product of desired shape and drying.

### Claim 17 (depends on 16)

A product as set forth in claim 16, wherein said product is a cellulosic sheet.

### Claim 18

A collagen strengthened cellulosic product, wherein said product is formed by a process comprising:
a. providing an aqueous ground slurry of insoluble collagen;
b. adjusting the water or solid content of said wet ground slurry whereby said insoluble collagen is at a concentration that promotes substantially maximum concentration and maximum molecular weight of said soluble collagen in a final product;
c. adjust the pH of said slurry from Step b to obtain activity for a proteolytic enzyme added in Step d;
d. adding and mixing said proteolytic enzyme with said pH adjusted slurry;
e. reacting the slurry of Step d at a temperature, T, and for a time, t, effective for forming a solution including soluble collagen derived from said insoluble collagen;
f. withdrawing at least some of the solution of Step e including soluble collagen as product;
g. mixing a cellulosic material selected from the group consisting of virgin paper pulp, broke, reclaimed newsprint, reclaimed carton container, or a mixture thereof with a solution comprising water, or water and NaOH, and mechanically pulping until a pulp slurry is formed having a consistency of about 3 to about 6 wt % based on dry pulp solids;
h. diluting said pulp slurry to a consistency of about 1 to about 3 wt % based on dry pulp solids and adjusting pH to about 3.5 to about 7.0;
i. adding said soluble collagen from Step g to said diluted pulp slurry in an amount from between about 0.1 to about 2 dry wt % soluble collagen (based on dry weight of cellulosic material), and mixing at a shear rate and at time effective for interaction of said diluted pulp slurry solids and soluble collagen, whereby at least a substantial portion of said soluble collagen is bound to said pulp to form a collagen pulp slurry;
j. diluting said collagen-pulp slurry to between about 0.1 dry wt % and about 1 dry wt % consistency; and
k. forming said collagen-pulp slurry into a cellulosic product of desired shape and drying.

### Claim 19 (depends on 18)

A product as set forth in claim 18, wherein said product is a cellulosic sheet.