A phenolic resin used in the field of ink and its preparation method

Abstract

The invention discloses a toughened modified phenolic resin. The modified phenolic resin is prepared by polymerizing an alkyl phenolic resin and an olefinic monomer. The toughened modified phenolic resin prepared by the invention can be used to manufacture ink for glass bottle labels. Because the toughened modified phenolic resin contains acrylic acid or acrylic ester, the carboxyl group or ester group can expose an acidic group -COOH directly or through hydrolysis after alkali washing. The presence of the acidic group makes the phenolic resin more soluble in water, which can reduce the amount of alkali used in the alkali washing process. At the same time, the modified phenolic resin has a higher degree of cross-linking, better toughness, higher strength under normal use conditions, stronger durability, and better compatibility with inorganic or organic dyes.

Description

Technical Field

[0001] The present invention relates to the field of polymers, and in particular to a phenolic resin applicable to the field of inks and a preparation method thereof. Background Art

[0002] Glass bottles are traditional beverage packaging containers in my country, and glass is a packaging material with a rich history. Despite the influx of numerous packaging materials, glass containers still hold a significant position in beverage packaging, thanks to their unique characteristics that are irreplaceable by other packaging materials. Key features of glass packaging containers include: non-toxicity and odorlessness; transparency, aesthetics, excellent barrier properties, airtightness, and a wide variety of raw materials, affordability, and multiple uses. They are also heat-resistant, pressure-resistant, and durable, and can be sterilized at high temperatures or stored at low temperatures. These numerous advantages have made them the preferred packaging material for many beverages, including beer, fruit tea, and jujube juice.

[0003] 71% of global beer is bottled in glass bottles, and China leads the world in glass bottle usage, accounting for 55% of global glass bottle consumption, exceeding 50 billion bottles annually. As the mainstream beer packaging, glass bottles are favored by the beer industry for their stable structure, pollution-free design, and low price. With the widespread use of glass bottles, the amount of glass bottles recycled is increasing annually, and this recycling volume is enormous and immeasurable. According to the Glass Packaging Association, the energy saved by recycling one glass bottle is equivalent to powering a 100-watt light bulb for four hours, running a computer for 30 minutes, or watching 20 minutes of television. Therefore, recycling glass is a significant undertaking.

[0004] Currently, breweries typically use bottle washers to clean glass beer bottles. The washing process involves pre-soaking, pre-spraying, alkali washing (typically three to four alkali tanks), hot water soaking and spraying, warm water soaking and spraying, and sterile water spraying. The purpose of this alkali wash is to reduce the adhesion of the adhesive between the label and the glass bottle. This not only removes visible dirt and old labels from the inside and outside of the beer bottle, but also kills microorganisms adhering to the bottle. The washed bottle should be free of "beading" on the wall.

[0005] During the alkali-based recycling and cleaning process for glass bottles, the printing ink on the glass bottle labels is difficult to clean due to its insoluble nature and accumulates in the cleaning tank. The printing ink in labels is primarily composed of resins, organic pigments, and other additives. Phenolic resins are alkali-soluble, making them useful in alkali-washable inks. They are also a key raw material for adhesives and are a widely used polymer in glass bottle labels. However, phenolic resins also have significant drawbacks, such as being hard, brittle, and prone to pulverization. Therefore, a phenolic resin with excellent flexibility and adhesion while maintaining alkali solubility is urgently needed. Summary of the Invention

[0006] The main purpose of the present invention is to solve the shortcomings of phenolic resin for labels in the prior art and to provide a phenolic resin that has good alkali solubility, good flexibility and adhesion, which can effectively solve the problems in the background technology.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A toughened modified phenolic resin is prepared by polymerizing an alkylphenolic resin and an olefin-containing monomer.

[0009] Preferably, the alkylphenolic resin is selected from One or more of, wherein R is H, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl or propyl, butyl, pentyl, hexyl, heptyl or octyl.

[0010] Furthermore, the alkenyl-containing monomer of the present invention is selected from one or more of acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, tert-butyl acrylate, hexyl acrylate, octyl acrylate, acrylamide, hydroxyethyl acrylate, hydroxypropyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate, and is preferably selected from a mixture of one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxypropyl methacrylate and acrylamide.

[0011] Furthermore, the alkenyl-containing monomer of the present invention contains multiple types of acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, tert-butyl acrylate, hexyl acrylate, octyl acrylate, acrylamide, hydroxyethyl acrylate, hydroxypropyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate, and must contain one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate and acrylamide, and the amount thereof is not less than 10%-50% of the mass of all monomers, preferably not less than 20%-50% of the mass of all monomers, preferably not less than 30%-50% of the mass of all monomers, and preferably not less than 30%-40% of the mass of all monomers.

[0012] Furthermore, the molecular weight of the alkylphenol-formaldehyde resin used in the toughened modified phenolic resin of the present invention is 500-20,000, preferably 600-1200, or 800-1000 or 1000-20,000, or 2,000-20,000, or 3,000-20,000, or 4,000-20,000, or 2,000-18,000, or 5,000-18,000, or 6,000-18,000, or 8,000-18,000, or 8,000-15,000, or 8,000-12,000, or 10,000-20,000.

[0013] Furthermore, the molar ratio of the alkenyl group in the alkylphenol resin used in the toughened modified phenolic resin of the present invention to the alkenyl group in the alkenyl-containing monomer is (0.8-1):(0.8-1), preferably 1:1.

[0014] Furthermore, the mass ratio of the alkyl phenolic resin to the olefinic monomer used in the toughened modified phenolic resin of the present invention is 1:0.3-5, preferably 1:0.4-4, preferably 1:0.5-3.8, preferably 1:0.8-3, preferably 1:1-2.5, preferably 1:1-2.

[0015] Furthermore, the toughened modified phenolic resin of the present invention is prepared by polymerizing the alkylphenolic resin and the olefin-containing monomer under the action of an initiator.

[0016] Furthermore, the initiator used in the toughened modified phenolic resin of the present invention is selected from azo and peroxide free radical initiators, more preferably one or more of benzoyl peroxide, lauroyl peroxide, azobisisobutyronitrile, and azobisisoheptonitrile.

[0017] Furthermore, the present invention also provides a method for preparing a toughened modified phenolic resin, which comprises the following steps: (a) dissolving an allyl phenolic resin in an organic solvent under stirring and heating; (b) slowly adding the prepared monomer and initiator dropwise under reflux for about 2-6 hours; (c) after the addition is completed, continuing the reaction at 60-80°C or the boiling point of the solvent for 4-8 hours to obtain the toughened modified phenolic resin.

[0018] Preferably, the organic solvent is selected from one or more of ethanol, isopropanol, and acetone; and the step (c) optionally comprises a step of removing the organic solvent after the reaction is completed.

[0019] The present invention also provides use of the toughened modified phenolic resin in preparing ink, wherein the ink further comprises a dye, and the dye is selected from one or more inorganic dyes or organic dyes.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The toughened modified phenolic resin of the present invention contains acrylic acid, acrylic ester or acrylamide; the carboxyl group or ester group can expose the acidic group -COOH directly or through hydrolysis after alkali washing; the acrylamide group is highly water-soluble, and hydroxyl-containing monomers such as hydroxyethyl acrylate have the effect of promoting water solubility; the acidic group has higher solubility in water and faster dissolution rate, which can reduce the amount of alkali used in the alkali washing step and shorten the dissolution time.

[0022] 2. The toughened modified phenolic resin of the present invention has a higher degree of cross-linking, better toughness, higher strength and greater durability under normal use conditions.

[0023] 3. The toughened modified phenolic resin of the present invention has better compatibility with inorganic or organic dyes. DETAILED DESCRIPTION

[0024] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0025] Example 1

[0026] Under heating and stirring, the average molecular weight of the structure is about 1000. An alkyl phenolic resin is dissolved in ethanol with a mass volume concentration of about 50 mg / ml. Hydroxyethyl acrylate and benzoyl peroxide are slowly added dropwise at 60°C, wherein the mass of the benzoyl peroxide is 5% of the mass of the alkyl phenolic resin. The addition is continued for about 3 hours, and the mass of the hydroxyethyl acrylate is 0.3 times the mass of the alkyl phenolic resin. After the addition is completed, the temperature is maintained at about 60°C for 5 hours, and the reaction solvent is evaporated under reduced pressure to obtain a toughened modified allyl phenolic resin.

[0027] Example 2

[0028] Under heating and stirring, the average molecular weight of the structure is about 800. An alkyl phenolic resin is dissolved in acetone at a mass volume concentration of 50 mg / ml. Hydroxyethyl methacrylate and azoisobutyronitrile are slowly added dropwise under reflux, wherein the mass of the azoisobutyronitrile is 5% of the mass of the alkyl phenolic resin. The addition is continued for about 3 hours, and the mass of the hydroxyethyl methacrylate is 0.5 times the mass of the alkyl phenolic resin. After the addition is completed, the mixture is heated under reflux for 5 hours, and the reaction solvent is evaporated under reduced pressure to obtain a toughened modified allyl phenolic resin.

[0029] Example 3

[0030] Under heating and stirring, the average molecular weight of the structure is about 1200. An alkyl phenolic resin is dissolved in acetone at a mass volume concentration of 50 mg / ml. Acrylamide and azoisobutyronitrile are slowly added dropwise under reflux conditions. The mass of the azoisobutyronitrile is 5% of the mass of the alkyl phenolic resin. The addition is continued for about 3 hours. The mass of the acrylamide is 0.4 times the mass of the alkyl phenolic resin. After the addition is completed, the mixture is heated under reflux for 5 hours, and the reaction solvent is evaporated under reduced pressure to obtain a toughened modified allyl phenolic resin.

[0031] Example 4

[0032] Under heating and stirring, the average molecular weight of the structure is about 1200. An alkyl phenolic resin is dissolved in acetone at a mass volume concentration of 50 mg / ml. Acrylamide and azoisobutyronitrile are slowly added dropwise at 60° C. The mass of the azoisobutyronitrile is 5% of the mass of the alkyl phenolic resin. The addition is continued for about 3 hours. The mass of the acrylamide is 0.4 times the mass of the alkyl phenolic resin. After the addition is completed, the mixture is heated under reflux for 5 hours, and the reaction solvent is evaporated under reduced pressure to obtain a toughened modified allyl phenolic resin.

[0033] Example 5

[0034] Under heating and stirring, the average molecular weight of the structure is about 800. An alkyl phenolic resin is dissolved in acetone at a mass volume concentration of 50 mg / ml. Under reflux, a mixture of hydroxyethyl methacrylate and acrylic acid in a molar ratio of 1:1 and azoisobutyronitrile are slowly added dropwise, wherein the mass of the azoisobutyronitrile is 5% of the mass of the alkyl phenolic resin. The addition is continued for about 3 hours, and the mass of the hydroxyethyl methacrylate and acrylic acid is 0.5 times the mass of the alkyl phenolic resin. After the addition is completed, the mixture is heated under reflux for 5 hours, and the reaction solvent is evaporated under reduced pressure to obtain a toughened modified allyl phenolic resin.

[0035] Test Example 1:

[0036] 1 g of the modified allyl phenolic resin prepared in Examples 1-5 and a commercially available phenolic resin were added to 10 ml of a 60° C. aqueous solution containing 1 g of sodium hydroxide and stirred at 200 rpm. The time required for the solution to fully dissolve was tested. See Table 1 for details.

[0037] Table 1

[0038]

[0039] Test Example 2:

[0040] 1 g of the modified allyl phenolic resin prepared in Examples 1-5 and a commercially available phenolic resin were added to 10 ml of a 60° C. aqueous solution containing 2 g of sodium hydroxide and stirred at 200 rpm. The time required for full dissolution was tested. See Table 2 for details.

[0041] Table 2

[0042]

[0043] Test Example 3

[0044] Hot pressing molding: The modified allyl phenolic resin prepared in Examples 1-5 and the commercially available phenolic resin were poured into a mold and hot pressed at a temperature of 150°C and a pressure of 16 MPa using a hot press. The pressure was maintained for 5 minutes during the hot pressing process, and the mold was opened and aired 4 times within 5 minutes before the pressure was maintained.

[0045] Heat treatment: The hot-pressed samples were placed in an oven and kept at 160°C for 12 hours. After cooling to room temperature, friction material samples were obtained. The obtained friction material samples were subjected to a constant speed test in accordance with GB5763-2008. The test results are shown in Table 3:

[0046] Table 3

[0047]

[0048] Note: The higher the friction coefficient of the friction material, the better the flexibility of the resin.

[0049] Test Example 4

[0050] The modified allyl phenolic resin prepared in Examples 1-5 was dissolved in acetone at a mass-to-volume ratio of 1:1.5. The resulting viscous substance was applied to conventional label paper. After the solvent evaporated, the thickness was tested to be about 0.1 mm. The number of times it could be bent was tested at 25°C, 10°C, and -5°C. The test results are shown in Table 4:

[0051] Table 4

[0052]

[0053]

[0054] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A toughened modified phenolic resin, characterized in that The toughened modified phenolic resin is prepared by polymerizing an alkyl phenolic resin and an olefin-containing monomer. The alkenyl-containing monomer is selected from one or more of acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, tert-butyl acrylate, hexyl acrylate, octyl acrylate, acrylamide, hydroxyethyl acrylate, hydroxypropyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate; The molar ratio of the alkenyl group in the alkenyl phenolic resin to the alkenyl group in the alkenyl group-containing monomer is (0.8-1): (0.8-1), The toughened modified phenolic resin is prepared by polymerization of olefinic phenolic resin and olefinic monomer under the action of an initiator; The preparation method of the toughened modified phenolic resin comprises the following steps: (a) dissolving an alkylphenolic resin in an organic solvent under stirring and heating; (b) slowly adding a prepared monomer and an initiator dropwise under reflux for 2-6 hours; and (c) after the addition is completed, continuing the reaction at 60-80°C or the boiling point of the solvent for 4-8 hours to obtain the toughened modified phenolic resin.

2. The toughened modified phenolic resin according to claim 1, characterized in that The alkenyl-containing monomers contain multiple ones of acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, tert-butyl acrylate, hexyl acrylate, octyl acrylate, acrylamide, hydroxyethyl acrylate, hydroxypropyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate, and must contain one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate and acrylamide, and the amount thereof is not less than 10%-50% of the mass of all monomers.

3. The toughened modified phenolic resin according to claim 1, characterized in that The molecular weight of the alkylphenol-formaldehyde resin is 500-20,000.

4. The method for preparing the toughened modified phenolic resin according to any one of claims 1 to 3, wherein It is prepared by polymerizing the olefinic phenolic resin and the olefinic monomer under the action of an initiator; The method comprises the following steps: (a) dissolving an alkylphenol-formaldehyde resin in an organic solvent under stirring and heating; (b) slowly adding a prepared monomer and an initiator dropwise under reflux for 2-6 hours; and (c) after the addition is completed, continuing the reaction at 60-80°C or the boiling point of the solvent for 4-8 hours to obtain a toughened modified phenol-formaldehyde resin.

5. The method for preparing the toughened modified phenolic resin according to claim 4, wherein The initiator is selected from one or more of azo and peroxide free radical initiators.

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