Long-acting high-viscosity starch wallpaper paste and preparation method thereof

Abstract

The application provides a long-acting high-viscosity starch wallpaper paste and a preparation method thereof. Starch is hydrolyzed by double-enzyme cooperation at pH 5-7 to obtain treated starch; the treated starch, inositol and halloysite are simultaneously heated and stirred in a water bath to obtain a FI / halloysite-starch mixed gel, which is used as a raw material to prepare the long-acting high-viscosity starch wallpaper paste. The double-enzyme cooperation has high hydrolysis efficiency, and the specific surface area of the hydrolysis product is larger, which is beneficial to the loading of inositol and halloysite; the halloysite can form hydrogen bonds with the hydroxyl groups in inositol and enzyme-treated starch, and enhance the intermolecular force, so that inositol, halloysite and enzyme-treated starch form a reticular crosslinked structure. The obtained wallpaper paste has high peeling strength and high viscosity performance in a high-humidity environment, improves the problems that the existing market wallpaper paste is prone to bulging and falling off in a high-humidity environment, and has a wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wallpaper glue, in particular to a long-acting high-viscosity starch wallpaper glue and a preparation method thereof. BACKGROUND

[0002] Wallpaper is a kind of widely used indoor decoration material. In recent years, because of its color variety, pattern richness, safety and environmental protection, convenient construction, and suitable price, it has been more and more recognized by the public and widely used in indoor decoration. The original paper of the wallpaper is usually produced by bleached chemical wood pulp, and then processed by different processes such as coating, printing, embossing or surface plastic covering, and finally cut, packaged and delivered. Because it has certain strength, beautiful appearance and good water resistance, it is widely used in indoor decoration of houses, offices, hotels and hotels.

[0003] However, the wallpaper needs to be bonded together by wallpaper glue. Generally, the wallpaper is pasted on the wall or wood board by using wallpaper powder, glue, wet glue, polyvinyl alcohol or white latex. Generally, the adhesive glue basically uses a large amount of organic solvents containing formaldehyde, which is not environmentally friendly or the formaldehyde exceeds the standard.

[0004] In recent years, waxy rice glue has become a kind of widely used wallpaper glue. Waxy rice glue is a general term for starch glue cooked by various modified starches at high temperature. Although waxy rice glue is environmentally friendly and non-toxic, due to different production processes and formulations of various manufacturers, the current waxy rice glue products are prone to retrogradation during use, especially in the high humidity environment in southern areas, which causes the waxy rice glue to deform and lose adhesion, resulting in more obvious problems such as wall paper bulging, blistering and falling off. SUMMARY

[0005] The purpose of the present application is to provide a long-acting high-viscosity starch wallpaper glue and a preparation method thereof, which overcomes and solves the problems of easy bulging and easy falling off of the current market wallpaper glue in high humidity environment.

[0006] The technical scheme of the present application is as follows:

[0007] A long-acting high-viscosity starch wallpaper glue comprises:

[0008]

[0009] The FI / attapulgite-starch mixed gel is obtained by cross-linking loading of inulin and attapulgite with starch.

[0010] In some embodiments, in the FI / attapulgite-starch mixed gel, the mass ratio of starch, inulin and attapulgite is 100-70:20-16:9-6.

[0011] In some embodiments, the long-acting high-viscosity starch wallpaper paste further comprises:

[0012] Mold inhibitor 1-5 parts.

[0013] In another aspect, the present application also provides a long-acting high-viscosity starch wallpaper paste and a preparation method thereof, comprising:

[0014] Step 1: uniformly disperse starch under weak acid conditions to obtain a starch suspension, add α-amylase and branching enzyme to the starch suspension and stir to react, filter, wash and dry the reaction solution to constant weight after the reaction is completed, crush and sieve to obtain treated starch;

[0015] Step 2: uniformly mix the treated starch prepared above, inulin (FI), and halloysite with water, heat and stir in a water bath after sealing to perform heat treatment, take out and cool after the sample is fully gelatinized, crush and sieve to obtain a FI / halloysite-starch mixed gel;

[0016] Step 3: uniformly mix the above FI / halloysite-starch mixed gel according to the formula to obtain the long-acting high-viscosity starch wallpaper paste.

[0017] In some embodiments, the starch is selected from one or a combination of several of cassava starch, potato starch, or corn starch.

[0018] In some embodiments, the pH of the starch suspension is 5-7; preferably, the pH of the starch suspension is 6.

[0019] In some embodiments, the addition ratio of the α-amylase and branching enzyme is 70000-90000 U / g: 1800-2100 U / g.

[0020] In some embodiments, the stirring reaction in step 1 is performed at a reaction temperature of 40-45℃ for 6-12h.

[0021] In some embodiments, the addition mass ratio of the treated starch, inulin, and halloysite in step 2 is 100-70: 20-16: 9-6; and the addition mass ratio of the treated starch and water is 1: 2-3.

[0022] In some embodiments, the heat treatment in step 2 is performed at a treatment temperature of 75-95℃ for 1-3h at a stirring speed of 120-200 rpm / min.

[0023] Beneficial effects:

[0024] The starch is hydrolyzed by the synergistic effect of double enzymes, the hydrolysis efficiency is high, and the hydrolysis product has small pore size and larger specific surface area, which is beneficial to the loading of inulin and halloysite; the starch gel properties of the modified starch are improved by cross-linking of halloysite, inulin and hydrolyzed starch, the hydrogen bonds can be formed between halloysite and inulin and starch, the intermolecular forces are enhanced, the reticulated cross-linked structure of inulin, halloysite and treated starch is formed, the anti-regeneration ability of the starch in a high humidity environment is improved, and excellent mechanical properties are brought. The wall paper glue prepared by the preparation method has high peel strength and high viscosity performance in a high humidity environment, the problems of easy bulging of the wall paper glue in the market in a high humidity environment and easy falling off after long-term use are improved, and the wall paper glue has wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings are included to provide a further understanding of the application, and constitute a part of the specification, and are used together with the specific embodiments described below to explain the application, but do not constitute a limitation on the application. In the drawings:

[0026] Figure 1 The infrared spectra of inulin, halloysite and starch wall paper glue-1 prepared in Example 1. DETAILED DESCRIPTION

[0027] The application will be described below in conjunction with specific embodiments. It should be noted that the following examples are examples of the application, and are only used to illustrate the application, and are not used to limit the application. Other combinations and various modifications within the concept of the application can be made without departing from the spirit or scope of the application.

[0028] The chemical reagents used in the application are commercially available unless otherwise specified. The cassava starch (food grade) used in the examples was purchased from Shanghai Lv Yuan Starch Co., Ltd.; the natural inulin FI (2< DP < 60) with a purity of 86.0% was purchased from Cosucra Company in Belgium and was used according to the needs; the halloysite used was halloysite nanotube, which was purchased from Guangzhou Runwo Material Technology Co., Ltd.; the corn starch was purchased from Jinan Tianhua Biological Technology Co., Ltd., and the potato starch was purchased from Shandong Xinxiangrui Chemical Co., Ltd.

[0029] The polyvinyl alcohol used in the examples was model 1788; the emulsifier was model OP-10; the stabilizer was glycerol monostearate; and the defoaming agent was polyoxyethylene polyoxypropyl alcohol amine ether, all of which were commercially available. The branching enzyme was purchased from Novozymes Company in Denmark, and the alpha-amylase was purchased from Shanghai Kefang Biological Technology Co., Ltd.

[0030] Example 1

[0031] Step 1: 50 g of cassava starch was weighed into a 250 mL conical flask, 200 mL of acetic acid-sodium acetate buffer solution with pH of 6 was added, and the mixture was preheated in a 45 °C water bath for 20 min while stirring. 3500000 U of α-amylase and 100000 U of branching enzyme were removed and added to the starch suspension, and the reaction was stopped after stirring at 45 °C for 12 h. The reaction solution was filtered through a Buchner funnel, the filter cake was washed with distilled water three times, and then dried in a 50 °C electric constant temperature drying oven until the weight was constant. The dried product was ground to pass through a 100 mesh sieve to obtain the treated starch.

[0032] Step 2: 100 g of the treated starch prepared in the above step, 18 g of inulin, and 7 g of halloysite nanotubes were added to 250 mL of deionized water at the same time, sealed, and placed in a magnetic stirring water bath at 90 °C with a stirring speed of 150 rpm / min for heat treatment for 1 h. After the sample was completely gelatinized, it was cooled to room temperature and stored in a refrigerator at 4 °C for 24 h. The product was ground to pass through a 100 mesh sieve to obtain the FI / halloysite-starch mixed gel.

[0033] Step 3: 15 parts of the FI / halloysite-starch mixed gel, 44 parts of polyvinyl alcohol, 1.5 parts of glycerol, 1 part of emulsifier, 0.4 parts of stabilizer, 1 part of defoaming agent, and 22 parts of deionized water were mixed uniformly to obtain the desired starch wallpaper paste-1.

[0034] The prepared starch wallpaper paste-1 was subjected to infrared detection together with raw starch, inulin, and halloysite, and the obtained data are shown in Figure 1 As can be seen from the figure, the starch wallpaper paste-1 has the same characteristic peaks as inulin at -2931 cm -1 , -1650 cm -1 , -1026 cm -1 , and -921 cm -1 ; and has the same characteristic peaks as halloysite at -3695 cm -1 , -532 cm -1 , and -464 cm -1 . In addition, the hydroxyl characteristic peak of the starch wallpaper paste-1 is red-shifted from 3392 cm -1 of the raw starch to 3345 cm -1 , which confirms that halloysite, inulin, and the like interact with the raw starch to form a crosslinked network, thereby improving the adhesive properties.

[0035] Example 2

[0036] Example 2 refers to the implementation of Example 1, except that the pH of the acetic acid-sodium acetate buffer solution is 5. The desired starch wallpaper paste-2 was prepared.

[0037] Example 3

[0038] Example 3 refers to the implementation of Example 1, except that the pH of the acetic acid-sodium acetate buffer solution is 6.5. The desired starch wallpaper paste-3 is prepared.

[0039] Example 4

[0040] Example 4 refers to the implementation of Example 1, except that the pH of the acetic acid-sodium acetate buffer solution is 7. The desired starch wallpaper paste-4 is prepared.

[0041] Example 5

[0042] Example 5 refers to the implementation of Example 1, except that the amounts of starch, inulin and halloysite nanotubes added are 100 g, 16 g and 9 g. The desired starch wallpaper paste-5 is prepared.

[0043] Example 6

[0044] Example 6 refers to the implementation of Example 1, except that the amounts of starch, inulin and halloysite nanotubes added are 100 g, 20 g and 6 g. The desired starch wallpaper paste-6 is prepared.

[0045] Example 7

[0046] Example 7 refers to the implementation of Example 1, except that corn starch is selected instead of cassava starch. The desired starch wallpaper paste-7 is prepared.

[0047] Example 8

[0048] Example 8 refers to the implementation of Example 1, except that potato starch is selected instead of cassava starch. The desired starch wallpaper paste-8 is prepared.

[0049] Comparative Example 1

[0050] Step 1: Take 100 g of cassava starch, 18 g of inulin and 7 g of halloysite nanotubes and add them to 250 ml of deionized water at the same time, then seal and place in a magnetic stirring water bath at 90°C with a stirring speed of 150 rpm / min for heat treatment for 1 h. After the sample is fully gelatinized, it is taken out and cooled to room temperature, then placed in a 4°C refrigerator for 24 h, and then crushed through a 100 mesh sieve to obtain FI / halloysite-starch mixed gel.

[0051] Step 2: Take 15 parts of the above FI / halloysite-starch mixed gel, 44 parts of polyvinyl alcohol, 1.5 parts of glycerol, 1 part of emulsifier, 0.4 parts of stabilizer, 1 part of defoaming agent and 22 parts of deionized water, and mix them uniformly to obtain wallpaper paste-1.

[0052] Comparative Example 2

[0053] Step 1: 50 g of cassava starch was weighed into a 250 mL conical flask, 200 mL of acetic acid-sodium acetate buffer solution with pH 6 was added, and it was preheated in a 45°C water bath for 20 min while stirring. 3500000 U of α-amylase and 100000 U of branching enzyme were removed and added to the starch suspension, and the reaction was stopped after stirring at 45°C for 12 h. The reaction liquid was filtered through a Buchner funnel, the filter cake was washed with distilled water three times, and it was dried in a 50°C electric thermostat air-drying oven until the weight was constant. It was crushed through a 100 mesh sieve to obtain the treated starch.

[0054] Step 2: 118 g of the treated starch prepared above and 7 g of halloysite nanotubes were added to 250 ml of deionized water, sealed, and placed in a magnetic stirring water bath at 90°C with a stirring speed of 150 rpm / min for heat treatment for 1 h. After the sample was fully gelatinized, it was removed and cooled to room temperature, and stored in a 4°C refrigerator for 24 h. It was crushed through a 100 mesh sieve to obtain a halloysite-starch mixed gel.

[0055] Step 3: 15 parts of the halloysite-starch mixed gel above, 44 parts of polyvinyl alcohol, 1.5 parts of glycerol, 1 part of emulsifier, 0.4 parts of stabilizer, 1 part of defoaming agent, and 22 parts of deionized water were mixed uniformly to obtain wallpaper glue-2.

[0056] Comparative Example 3

[0057] Step 1: 50 g of cassava starch was weighed into a 250 mL conical flask, 200 mL of acetic acid-sodium acetate buffer solution with pH 6 was added, and it was preheated in a 45°C water bath for 20 min while stirring. 3500000 U of α-amylase and 100000 U of branching enzyme were removed and added to the starch suspension, and the reaction was stopped after stirring at 45°C for 12 h. The reaction liquid was filtered through a Buchner funnel, the filter cake was washed with distilled water three times, and it was dried in a 50°C electric thermostat air-drying oven until the weight was constant. It was crushed through a 100 mesh sieve to obtain the treated starch.

[0058] Step 2: 107 g of the treated starch prepared above and 18 g of inulin were added to 250 ml of deionized water, sealed, and placed in a magnetic stirring water bath at 90°C with a stirring speed of 150 rpm / min for heat treatment for 1 h. After the sample was fully gelatinized, it was removed and cooled to room temperature, and stored in a 4°C refrigerator for 24 h. It was crushed through a 100 mesh sieve to obtain a FI-starch mixed gel.

[0059] Step 3: 15 parts of the FI-starch mixed gel above, 44 parts of polyvinyl alcohol, 1.5 parts of glycerol, 1 part of emulsifier, 0.4 parts of stabilizer, 1 part of defoaming agent, and 22 parts of deionized water were mixed uniformly to obtain wallpaper glue-3.

[0060] Comparative Example 4

[0061] Step 1: 50 g of cassava starch was weighed into a 250 mL conical flask, 200 mL of acetic acid-sodium acetate buffer solution with pH 6 was added, and it was preheated in a 45 °C water bath for 20 min while stirring. 3500000 U of α-amylase and 100000 U of branching enzyme were removed and added to the starch suspension, which was stirred at 45 °C for 12 h to stop the reaction. The reaction liquid was filtered through a Buchner funnel, the filter cake was washed with distilled water three times, and it was dried in a 50 °C electric constant temperature air-drying oven until the weight was constant. It was crushed through a 100 mesh sieve to obtain the treated starch.

[0062] Step 2: 125 g of the treated starch prepared above was added to 250 ml of deionized water, sealed and placed in a magnetic stirring water bath at 90 °C with a stirring speed of 150 rpm / min for 1 h. After the sample was fully gelatinized, it was removed and cooled to room temperature, and then stored at 4 °C for 24 h. It was crushed through a 100 mesh sieve to obtain a starch mixed gel.

[0063] Step 3: 15 parts of the above starch mixed gel, 44 parts of polyvinyl alcohol, 1.5 parts of glycerol, 1 part of emulsifier, 0.4 parts of stabilizer, 1 part of defoaming agent, and 22 parts of deionized water were mixed uniformly to obtain wallpaper glue-4.

[0064] The wallpaper glue prepared in Examples 1-8 and Comparative Examples 1-4 above was subjected to the following experiments:

[0065] Experiment 1: The colloidal viscosity of the products of Examples 1-8 and Comparative Examples 1-4 was measured using an NDJ-1 viscometer, and the average value of the parameters was calculated by measuring 5 times.

[0066] Experiment 2: The products of Examples 1-8 and Comparative Examples 1-4 were evenly coated on 200x150x4mm asbestos-free fiber cement flat plates, and after 5 min, standard paper bases were pasted on them using a roller, and they were rolled back and forth under their own weight for five times, and then placed in an environment with a temperature of 33 °C and a relative humidity of 55%, and the edge curling time of the pasted standard paper base was tested.

[0067] Experiment 3: The products of Examples 1-8 and Comparative Examples 1-4 were evenly coated on 200x150x4mm asbestos-free fiber cement flat plates, and after 5 min, standard paper bases were pasted on them using a roller, and they were rolled back and forth under their own weight for five times, and then placed for 48 h, and the peel strength of the wallpaper glue was tested according to JCT548-2016; after 10 cycles of freezing and thawing from 0 °C to 25 °C, the peel strength was tested again.

[0068] The data measured in the above experiments are shown in Table 1.

[0069] Table 1 Test data table of experiments 1-3

[0070]

[0071]

[0072] It can be seen from Examples 1-4 and Comparative Example 1 that the double-enzyme synergistic hydrolysis of cassava starch has a competitive effect on the reaction system, the hydrolysis efficiency of the double-enzyme synergistic hydrolysis is higher than that of single-enzyme hydrolysis, and selecting a suitable pH promotes hydrolysis, which is beneficial to smaller pore size and larger specific surface area of the hydrolysis product, and is more conducive to the loading of inulin and halloysite. It can be seen from the examples and Comparative Examples 2-4 that inulin and halloysite can bring stable high viscosity and high peel strength to the gelatinized starch, and even if the product is placed in a high humidity environment, the normal use of the product can be ensured. This is because the addition of an appropriate amount of inulin can improve the processing properties of starch gel and its anti-regeneration ability in a high humidity environment; and halloysite can form hydrogen bonds with the hydroxyl groups in inulin and cassava starch, thereby enhancing the intermolecular forces and bringing excellent peel strength to the wallpaper glue product.

[0073] The FI / halloysite-starch mixed gel prepared by using inulin and halloysite modified cassava starch as raw materials to prepare wallpaper glue has high peel strength and high viscosity performance in a high humidity environment, which improves the problems of easy bulging and easy peeling of the existing market wallpaper glue in a high humidity environment, and has a broad application prospect.

[0074] The present application can also be embodied in other various embodiments without departing from the spirit and essential characteristics thereof, and those skilled in the art can make various corresponding changes and modifications to the present application according to the present application, but these corresponding changes and modifications should all belong to the protection scope of the appended claims of the present application.

Claims

1. A long-lasting, high-viscosity starch wallpaper adhesive, characterized in that, include: FI / Halloysite-starch mixed gel 14-23 parts 33-45 parts of polyvinyl alcohol Glycerol 1-1.5 parts Emulsifier 0.8–1.7 parts Stabilizer 0.3-0.8 parts 1 to 1.2 parts of defoamer 20-33 parts deionized water The FI / haloite-starch hybrid gel was obtained by cross-linking and loading inulin and halloysite with starch; The preparation method of the FI / halostone-starch mixed gel includes: Step 1: Disperse starch evenly under weak acid conditions to obtain starch suspension. Add α-amylase and branching enzyme to starch suspension and stir to react. After the reaction is completed, filter, wash and dry the reaction solution to constant weight, pulverize and sieve to obtain processed starch. Step 2: Take the treated starch, inulin and halloysite prepared above and mix them evenly with water. After sealing, heat the mixture in a water bath and stir. After the sample is fully gelatinized, take it out and cool it. Crush and sieve it to obtain FI / haloysite-starch mixed gel. The mass ratio of starch, inulin and halloysite is 100–70:20–16:9–6.

2. The long-lasting, high-viscosity starch wallpaper adhesive according to claim 1, characterized in that, Also includes: 1 to 5 parts of antifungal agent.

3. A method for preparing a long-lasting, high-viscosity starch wallpaper adhesive according to any one of claims 1-2, characterized in that, include, Step 1: Disperse starch evenly under weak acid conditions to obtain starch suspension. Add α-amylase and branching enzyme to starch suspension and stir to react. After the reaction is completed, filter, wash and dry the reaction solution to constant weight, pulverize and sieve to obtain processed starch. Step 2: Take the treated starch, inulin and halloysite prepared above and mix them evenly with water. After sealing, heat the mixture in a water bath and stir. After the sample is fully gelatinized, take it out and cool it. Crush and sieve it to obtain FI / haloysite-starch mixed gel. Step 3: Mix the above FI / halostone-starch mixed gel evenly according to the formula to obtain the long-lasting high viscosity starch wallpaper adhesive as described in claim 1 or 2.

4. The preparation method of the long-lasting high-viscosity starch wallpaper adhesive according to claim 3, characterized in that, The starch is selected from one or a combination of tapioca starch, potato starch, or corn starch.

5. The preparation method of the long-lasting high-viscosity starch wallpaper adhesive according to claim 3, characterized in that, The pH of the starch suspension is 6.

6. The preparation method of the long-lasting high-viscosity starch wallpaper adhesive according to claim 3, characterized in that, The ratio of α-amylase to branching enzyme is 70,000–90,000 U / g: 1,800–2,100 U / g.

7. The preparation method of the long-lasting high-viscosity starch wallpaper adhesive according to claim 3, characterized in that, In step 1, the stirring reaction is carried out at a temperature of 40–45°C for 6–12 hours.

8. The preparation method of the long-lasting high-viscosity starch wallpaper adhesive according to claim 3, characterized in that, In step 2, the mass ratio of the treated starch, inulin and halloysite added is 100-70:20-16:9-6; the mass ratio of the treated starch to water added is 1:2-3.

9. The preparation method of the long-lasting high-viscosity starch wallpaper adhesive according to claim 3, characterized in that, In step 2, the heat treatment temperature is 75-95℃, the treatment time is 1-3h, and the stirring speed is 120-200rpm.

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