JPH1143663A - Liquid adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a liq. adhesive which does not cause wrinkles or curls at all even when applied to a paper, esp. a thin paper, and is excellent in adhesive strength and inital adhesiveness by compounding a water-soluble adhesive polymer, a substance which limits the action of free water, and an aq. medium in such a manner as to give the adhesive a viscosity enabling the application to a paper. SOLUTION: A saccharide is an example of a substance which limits the action of free water, i.e., a substance which has properties limiting by the hydration action, etc., among water molecules. A starch hydrolyzate, e.g. dextrin or a powder candy, is an example of a substance which by itself acts as a water-soluble adhesive polymer and simultaneously acts as a substance which limits the action of free water. A water-soluble adhesive polymer having pyrrolidone groups, such as polyvinylpyrrolidone and/or a polyvinylpyrrolidone copolymer, can also be listed as a substance which exhibits both the actions. Pref., the solid conent (nonvolatile content) is set at 50 % or higher.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a novel adhesive which is free from wrinkles when adhering paper, especially thin paper, and which is comparable to conventional liquid adhesives in adhesive strength and initial adhesiveness. Liquid adhesive.

[0002]

[Related Art] Conventionally, adhesives for household, office or industrial use for bonding paper and the like include liquid,
Emulsions, latexes, and pastes (in the present specification, these adhesives are collectively referred to as liquid adhesives) and solid adhesives (stick glue).

[0003] Conventional liquid adhesives include starch, modified starch, arabic gum, polyacrylate,
A composition comprising a water-soluble adhesive polymer such as polyvinyl acetate, polyvinyl alcohol, a water-soluble cellulose derivative and polychloroprene and an aqueous medium such as water is generally widely used.

[0004] When this conventional liquid adhesive is applied to paper, there are inconveniences such as wrinkling of the applied paper over time, curling of the paper, and waving even after pasting the paper. What happens is a common experience. The generation of wrinkles and the like is particularly remarkable when a liquid adhesive is applied to thin paper.

For example, when attaching a newspaper clip to a mount using a liquid adhesive, copying text in a book and attaching it to a notebook, laying out various pieces of paper and laying out on a predetermined sheet such as an imitation paper. Many people experience that wrinkles and curls are generated at the time of pasting, and that the appearance of the wrinkles and curls remains undisturbed even after the liquid adhesive dries. .

[0006] Further, in the case of handicrafts using paper, liquid adhesives are often used, but wrinkles and curls still occur, which may ruin the value of handicrafts, In particular, there are many steps of attaching various pieces of paper, and even in such a step, it is a major problem how the generation of wrinkles and curls can be eliminated and the sheet can be attached exactly.

[0007] The paper has a structure in which elongated plant fibers such as pulp are immobilized, and a sparse portion where pulp fibers and the like exist in a sparse state and a dense portion where the pulp fibers and the like exist in a dense state coexist.
When a liquid adhesive is applied to the surface of paper, an aqueous medium such as water contained in a large amount in the liquid adhesive acts, so that free water penetrates into a dense part of the fixed pulp fiber and the like, and the dense part is Even if the pulp fiber or the like is displaced and free water does not exist due to evaporation or the like, the displacement of the pulp fiber or the like in the dense portion almost remains as it is, and it is considered that wrinkles and curls are generated. Even if an aqueous medium such as water enters the above-mentioned sparse part, the sparse part has many voids, and the aqueous medium such as water enters the voids. There is no cause for.

For example, solid adhesives (solid glue, stick glue) do not penetrate into any of the sparse and dense portions of the paper, so that wrinkles and curls etc. are formed on the paper even when applied to thin paper. It does not occur. Solid adhesives are superior to conventional liquid adhesives in this respect, but have the drawback that they are inferior in adhesive strength because they cannot exert an anchoring effect because the adhesive component does not enter the sparse part. .

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has no wrinkles or curls even when applied to paper, especially thin paper. It is an object of the present invention to provide a novel liquid adhesive which is not inferior in adhesive strength and initial adhesiveness as compared with a liquid adhesive.

[0010]

According to a first aspect of the present invention, there is provided a liquid adhesive comprising a water-soluble adhesive polymer, a substance that restricts the activity of free water, and an aqueous medium. And has a viscosity applicable to paper.

A second aspect of the liquid adhesive of the present invention comprises a water-soluble adhesive polymer, a saccharide, and an aqueous medium, and has a viscosity applicable to paper.

A third aspect of the liquid adhesive of the present invention comprises a starch decomposed product and an aqueous medium, and has a viscosity applicable to paper. As the starch degradation product, dextrin and / or powdered candy is suitable.
In the case of this liquid adhesive composition, it is possible to further add a saccharide.

A fourth aspect of the liquid adhesive according to the present invention comprises a water-soluble adhesive polymer having a pyrrolidone group and an aqueous medium, and has a viscosity applicable to paper.

As the water-soluble adhesive polymer having a pyrrolidone group, polyvinylpyrrolidone and / or a polyvinylpyrrolidone copolymer are preferably used.

The above-mentioned water-soluble adhesive polymer has a gelling property in a short time after application and bonding, and becomes sticky. In other words, it has the property of increasing the viscosity only by slightly reducing the water content, and the adhesive layer is not hard after drying. A material which is not brittle, that is, has a property of maintaining flexibility is applied.

As the substance that restricts the activity of free water, a material having a property of restricting the activity of free water in the liquid adhesive of the present invention by, for example, hydration with water molecules is used. Sugars can be mentioned as this substance.

In addition, there are substances that alone act as substances that restrict the activities of the water-soluble adhesive polymer and free water, and these substances are extremely suitable as the main components of the liquid adhesive of the present invention.

For example, starch degradation products such as dextrin, especially yellow dextrin and powdered candy, have a water-soluble adhesive polymer component and a saccharide component, and therefore, alone, restrict the activities of the water-soluble adhesive polymer and free water. Has properties. In addition, pullulan or the like can be used.

Further, for example, a water-soluble adhesive polymer having a pyrrolidone group, for example, polyvinylpyrrolidone and / or a polyvinylpyrrolidone copolymer (a vinylpyrrolidone / vinyl acetate copolymer or a vinylpyrrolidone / acrylic acid copolymer) is In addition to having properties as a water-soluble adhesive polymer, it has a property of restricting the activity of free water because it has a pyrrolidone group that is easily hydrated.

In the liquid adhesive of the present invention, it is necessary to limit the activity of free water as much as possible. For this purpose, the amount of water in the composition is limited to a predetermined amount or less to limit the amount of free water at first. This is very important. In the liquid adhesive of the present invention, the solid content (non-volatile content) is 50% or more, preferably 5% or more.
It is suitable to set it to 5% or more, more preferably 60% or more. Although the upper limit of the solid content (non-volatile content) is naturally determined, the upper limit value of the solid content (non-volatile content) is also determined by setting the viscosity applicable to paper as described above. .

The viscosity of the liquid adhesive of the present invention is determined by its upper limit being that it can be applied to paper.
If the viscosity is too high, it cannot be applied to paper, so it is necessary to lower the viscosity appropriately. If the viscosity is about 2000 poise or less, it can be applied directly, but if it is about 800 poise or less, it can flow in the bottle, so it can be applied using a bottle with a sponge or spatula at the tip. It is possible.

Specific examples of the water-soluble adhesive polymer include copolymers of polyvinyl alcohol, polyacrylic acid (including acrylic acid copolymer) and its alkali salts, polyacrylamide, polyvinylpyrrolidone, polyvinyl alkyl ether, and carboxylic acid. Polyvinyl acetate, starch, modified starch, dextrin (white dextrin, yellow dextrin), gum arabic and / or cellulose derivatives are preferably used. Examples of the cellulose derivative include methyl cellulose, ethyl cellulose, carboxymethyl cellulose (CMC), sodium carboxymethyl cellulose, calcium carboxymethyl cellulose, and the like. In addition, sodium alginate, propylene glycol alginate, sodium starch glycolate, sodium starch phosphate, sodium polyacrylate and the like can also be used. These water-soluble polymers can be used alone or in combination of two or more.

Further, preferred water-soluble adhesive polymers include a saponification degree of 55 to 100 mol% and an average polymerization degree of 150 to 100 mol%.
2,000 polyvinyl alcohol, or polyvinylpyrrolidone having an average molecular weight of 8,000 to 2,000,000, or a saponification degree of 60 to 100 mol%, and an average polymerization degree of 1.0
Polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, or polyacrylic acid having an average degree of polymerization of 1,000 to 50,000 and its sodium salt, potassium salt, ammonium salt, or average polymerization of from 00 to 66,000 Polyacrylic amide having a degree of 100 to 50,000, or polyoxyethylene having an average degree of polymerization of 10,000 to 100,000, or polyvinyl formal having a degree of acetalization of 0 to 15 mol% and an average degree of polymerization of 150 to 2,000, Polyvinyl acetalized resins such as polyvinyl acetoacetal, polyvinyl propional, and polyvinyl butyral, or polyvinyl ether resins such as polyvinyl methyl ether, polyvinyl ethyl ether, and polyvinyl isobutyl ether having an average degree of polymerization of 500 to 5,000, or crotonic acid Itaconic acid, acrylic acid, methacrylic acid, maleic acid, maleic anhydride, unsaturated monobasic acid or dibasic acid such as fumaric acid is converted to vinyl acetate, methyl acrylate, ethyl acrylate, butyl acrylate, etc. from 1 to 15 Mole% copolymerized modified vinyl acetate, copolymerized modified acrylic acid ester, one or a mixture of two or more water-soluble polymers thereof can be mentioned.

Specific examples of the above saccharides include monosaccharides, disaccharides, trisaccharides, tetrasaccharides, other oligosaccharides and / or polysaccharides, starch sugars, reduced water candy, or sugar alcohols. .

The monosaccharides include erythrose, xylose, ribose, arabinose, galactose, glucose (glucose), sorbose, fructose (fructose),
Mannose and the like. Oligosaccharides and polysaccharides include disaccharides: sucrose (sucrose), trehalose, isotrehalose, isosaccharose, palatinose, maltose (maltose), cellobiose, gentiobiose, melibiose, turanose, sophorose, lactose (lactose), and the like. Sugars: maltotriose, isomaltotriose, etc., tetrasaccharides: maltotetraose, isomalteose, etc., as well as water syrups according to saccharification degree. Granulated sugar or white sugar can also be used as the saccharide.

Although any of these saccharides can be used without any problem, the higher the solubility in water at low temperatures, the more suitable they are used. In this regard, sucrose is most preferred because its solubility in water at low temperatures is higher than other saccharides.

Examples of the starch sugars include water candy, powdered candy, oligosaccharides, low saccharified water candy (dextrin), high saccharified water candy (mixture of glucose and oligosaccharide), maltose (maltose), butose sugar (glucose) and the like. Can be given.

Examples of the reduced water candy include hydrogenated oligosaccharides, hydrogenated dextrin (reduced reduced water candy), sorbitol, hydrogenated oligosaccharides (highly saccharified reduced water candy), reduced maltose (maltitol) And reduced glucose (sorbitol) can be used.

As the sugar alcohols, monosaccharide alcohols, disaccharide alcohols, trisaccharide alcohols, tetrasaccharide alcohols, and other oligosaccharide alcohols and / or polysaccharide alcohols can be used.

Examples of the monosaccharide alcohol include glycerol, erythritol, xylitol, ribitol, arabitol, galactitol, sorbitol, iditol, mannitol and the like. Oligosaccharide alcohols and polysaccharide alcohols include palatinit, maltitol, lactitol, maltotriitol, isomaltitol, maltotetriitol, isomaltetriteol, etc., as well as glycan-reduced water candy. Can be.

As the saccharide used in the present invention, monosaccharides,
If low molecular weight saccharides such as disaccharides are used, the moisture resistance may decrease.If moisture resistance is required, the amount of low molecular weight saccharides should be such that the moisture resistance is not affected. Or it is better not to use.

As the aqueous medium, water is used. Needless to say, a preservative, a viscosity stabilizer, an antioxidant, a coloring agent, a fragrance and the like may be added as needed.

As described above, the conventional liquid adhesive is replaced with paper,
In particular, wrinkles, curls, and the like of the paper generated when applied to thin paper are due to the action of an aqueous medium such as water contained in a large amount in the applied liquid adhesive. This can be seen from the fact that wrinkles, curls and the like also occur even when only water is applied to paper.

The inventor of the present invention has found that by restricting the action of an aqueous medium such as water, which is necessarily contained as an essential component of the liquid adhesive, it is possible to reduce wrinkles and curls on paper coated with the liquid adhesive, especially thin paper. As a result of conducting various studies from the viewpoint that it is possible to prevent the occurrence of water molecules, the addition of substances that restrict the activity of free water, such as saccharides, as a component of the liquid adhesive, causes water molecules in the aqueous medium to The free water (free water) decreases due to the hydration during the operation, which greatly restricts the water activity. Even if a liquid adhesive is applied to paper, especially thin paper, wrinkles and curls may occur. It has been found that this does not occur, and the present invention has been reached.

[0035]

Embodiments of the present invention will be described below.

(Examples 1 to 6) Gohsenol GL03
(Product name of partially saponified poval, manufactured by Nippon Synthetic Chemical Co., Ltd., saponification degree: 88 mol%, 4% aqueous solution, viscosity: 3.4
mPa · s 120 ° C.): White sugar and water (remainder) were blended in the ratio shown in Table 1 to prepare a liquid adhesive. The coating properties, wrinkle resistance and adhesiveness (initial adhesive rise time and adhesive strength) of these liquid adhesives were examined.
It was shown to.

[0037]

[Table 1]

(Applicability test) Each liquid adhesive prepared in a 40 ml polyethylene bottle with a sponge application nozzle as shown in FIG. 1 [container used for office glue "My Glue NM35" manufactured by Nishiki Glue Industry Co., Ltd.] Copy paper [NBS Ricoh Co., Ltd., neutral dry PP]
It was observed whether the liquid adhesive easily flowed to the nozzle portion when the above-mentioned polyethylene bottle was applied upside down and spread over the paper “My Paper”].

The notation for applicability evaluation is as follows. A: The coating spreads well and the flow to the nozzle is very good. ：: Both the spread of the coating and the flow to the nozzle part are slightly reduced, but can be used without any problem. Δ: Can be spread, but has little flow.

(Wrinkle resistance test) Copy paper [N Corporation
Each liquid adhesive was applied to the back side of a neutral dry PP paper “My Paper” manufactured by BS Ricoh or a manuscript paper “K10” manufactured by KOKUYO Co., Ltd. using the application nozzle shown in FIG. Observe whether the paper is wrinkled 30 minutes after bonding.

The notation for evaluation of wrinkle resistance is as follows. ◎: No wrinkles. ：: Almost no wrinkles. Δ: Some unevenness due to wrinkles appears.

(Adhesion test) Initial adhesive rise time Immediately after applying each liquid adhesive to the copy paper with the sponge application nozzle, apply it at 1, 2, 3, 5, 10, 15, 30, 60 at 20 ° C. and 60% RH. After one minute, peel off by hand and measure the time at which the resistance develops.

2. Adhesive force In the same manner as in the measurement of the initial adhesive rise time, the pasted copy paper was peeled off by hand three days later, and the adhesive performance was observed.

The notation of the adhesive strength evaluation is as follows. A: Copy paper was broken. ：: Well attached. Δ: Partially attached.

As is clear from the results in Table 1, Example 1
Each of the liquid adhesives Nos. To 6 showed good results in all of the coating properties, wrinkle resistance and adhesiveness in the range of the proportion of each component having a solid content of 50% or more.

(Examples 7 to 9) White sugar, glucose, sorbitol S [Niken Kagaku Co., Ltd.] was added to Gohsenol GL03.
D-sorbitol solution, water 30%], RESIS [manufactured by Towa Kasei Kogyo Co., Ltd., crystalline maltitol (purity 99%)]
And water (remainder) in the proportions shown in Table 2, respectively.
A liquid adhesive was prepared.

Each test was performed in the same manner as in Examples 1 to 6, and as shown in Table 2, good results were similarly obtained.

[0048]

[Table 2]

(Examples 10 and 11) Gum arabic, white sugar, lysis (Towa Kasei Kogyo Co., Ltd., crystal maltitol, purity 99%) and water (remainder) were blended in the proportions shown in Table 3 to obtain a liquid. An adhesive was prepared.

Each test was performed in the same manner as in Examples 1 to 6, and as shown in Table 3, similar good results were shown.

[0051]

[Table 3]

(Examples 12 to 14) Gohsenol GL0
3, Gohsenol KL03 [manufactured by Nippon Gohsei Chemical Co., Ltd., partially saponified poval, degree of saponification 80 mol%, 4% aqueous solution, viscosity 2.6 mPa · s / 20 ° C.], white sugar, IP
A, rodin soda (NaSCN) and water (remainder)
And a liquid adhesive was prepared.

Each test was performed in the same manner as in Examples 1 to 6, and as shown in Table 4, good results were similarly shown.

[0054]

[Table 4]

(Examples 15 to 20) Dextrin 102
-S [Yellow Chemical Co., Ltd., yellow dextrin, DE:
3.2], dextrin 3 [manufactured by Nisseki Chemical Co., Ltd., white dextrin, DE: 2.4], white sugar, SLD-22
[Sanmatsu Kogyo Co., Ltd., powdered syrup, DE: 22], SLD
-32 [Sanmatsu Kogyo Co., Ltd., powdered syrup, DE: 32],
Hymal-38 [Sanmatsu Kogyo Co., Ltd., Enzymatic Saccharified Candy, D
E: 38, water 25%] and water (remainder) in the proportions shown in Table 5 to prepare a liquid adhesive. DE refers to a value obtained by measuring reducing sugars and expressing them as glucose and calculating the percentage as a percentage of solids, and is an abbreviation for dextroseequivalent.

Each test was performed in the same manner as in Examples 1 to 6, and as shown in Table 5, similar good results were shown.

[0057]

[Table 5]

Examples 21 to 26 Polyacrylic acid (2
5% solution), Rubiscol K60S (polyvinylpyrrolidone, liquid, molecular weight 450,000, solid content 45%),
Rubiscol VA64 (vinylpyrrolidone / vinyl acetate copolymer, powder form, molecular weight 44,000, solid content 1
00%), Rubiscol K90 (polyvinylpyrrolidone, powder, molecular weight 1,200,000, solid content 1)
00%), white sugar, SLD-32 and water (remainder).
And a liquid adhesive was prepared.

Each test was performed in the same manner as in Examples 1 to 6, and as shown in Table 6, good results were similarly obtained.

[0060]

[Table 6]

(Examples 27 and 28) Rubiscol VA
64, Rubiscol K30 (polyvinylpyrrolidone, powder, molecular weight 45,000, solid content 100%) and water (remainder) were blended in the proportions shown in Table 7 to prepare a liquid adhesive.

Each test was performed in the same manner as in Examples 1 to 6, and as shown in Table 7, similar good results were shown.

[0063]

[Table 7]

[0064]

The liquid adhesive of the present invention has no wrinkles or curls even when applied to paper, especially thin paper, and has a lower adhesive strength and initial adhesiveness than conventional liquid adhesives. Adhesion of paper, especially thin paper,
The work of pasting the cutout of the newspaper to the mount, laying out various pieces of paper and pasting it to imitation paper etc. can be performed extremely handsomely and neatly, and handicrafts using paper become easy to manufacture, and The finish is extremely beautiful, and wrinkles and curls are not generated even in the industrial paper laminating process, so that the working efficiency is improved and the occurrence rate of defective products is extremely reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a polyethylene bottle as a sponge coating nozzle used in a coating test of an example.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09J 129/04 C09J 129/04 B 129/10 129/10 131/04 131/04 B 133/02 133/02 133/26 133 / 26 139/06 139/06 201/02 201/02 (72) Inventor Yukio Komaba 4-5-9 Higashi Gotanda, Shinagawa-ku, Tokyo Inside Smedine Co., Ltd. (72) Inventor Takao Yoneyama Shinagawa-ku, Tokyo 4-5-9 Gotanda Se Medine Co., Ltd. (72) Inventor Yoshiaki Totsuka 3-47-3 Kyojima, Sumida-ku, Tokyo Nishiki Glue Industry Co., Ltd.

Claims (13)

[Claims] 1. A liquid adhesive comprising a water-soluble adhesive polymer, a substance that restricts the activity of free water, and an aqueous medium, and having a viscosity applicable to paper. 2. A liquid adhesive comprising a water-soluble adhesive polymer, a saccharide and an aqueous medium, having a viscosity applicable to paper. 3. A composition comprising a starch degradation product and an aqueous medium,
A liquid adhesive having a viscosity applicable to paper. 4. The liquid adhesive according to claim 3, wherein the degraded starch is dextrin or powdered candy. 5. A liquid adhesive comprising a water-soluble adhesive polymer having a pyrrolidone group and an aqueous medium and having a viscosity applicable to paper. 6. The liquid adhesive according to claim 5, wherein the water-soluble adhesive polymer having a pyrrolidone group is polyvinylpyrrolidone and / or a polyvinylpyrrolidone copolymer. 7. The liquid adhesive according to claim 3, further comprising a saccharide. 8. The liquid adhesive according to claim 1, wherein a solid content (non-volatile content) is 50% or more. 9. The water-soluble adhesive polymer is polyvinyl alcohol, polyacrylic acid and an alkali salt thereof, polyacrylamide, polyvinylpyrrolidone, polyvinylpyrrolidone copolymer, polyvinylalkyl ether, polyvinyl acetate copolymerized with carboxylic acid, The liquid adhesive according to claim 1, wherein the adhesive is starch, modified starch, modified starch, starch derivative, dextrin, arabic gum and / or cellulose derivative. 10. The method according to claim 2, wherein the saccharide is a monosaccharide, disaccharide, trisaccharide, tetrasaccharide, other oligosaccharide and / or polysaccharide. Liquid adhesive. 11. The liquid adhesive according to claim 2, wherein the saccharide is starch saccharide, reduced water candy, or sugar alcohol. 12. The starch saccharide according to claim 11, wherein the starch saccharide is water candy, powdered candy
2. Glucose or isomerized sugar.
2. The liquid adhesive according to 1. 13. The liquid adhesive according to claim 11, wherein the sugar alcohol is a monosaccharide alcohol, a disaccharide alcohol, a trisaccharide alcohol, a tetrasaccharide alcohol, another oligosaccharide alcohol and / or a polysaccharide alcohol. Agent.