JPH04103652A - Composition and adhesive - Google Patents

Abstract

PURPOSE:To obtain a composition suitable for adhesive for paper, having excellent initial bond strength, high-speed coating performances and ready handleability by blending a polyvinyl alcohol having specific polymerization degree with a filler and/or a resin selected from a natural paste, etc. CONSTITUTION:(A) 100 pts.wt. polyvinyl alcohol having >=4,000, preferably >=10,000 average polymerization degree is blended with (B) 10-500 pts.wt. filler (e.g. clay such as kaolinite), or 100 pts.wt. component A is mixed with (C) 100-10,000 pts.wt., preferably 1,000-7,000 pts.wt. one or more selected from a natural paste, a processing paste, a synthetic resin emulsion and a polyvinyl alcohol having <4,000 average polymerization degree or 10-500 pts.wt. component B, based on total amounts of 100 pts.wt. component A and 100-10,000 pts.wt. component C.

Description

DETAILED DESCRIPTION OF THE INVENTION A. INDUSTRIAL APPLICATION The present invention relates to compositions and adhesives. More specifically, the present invention relates to an adhesive for paper that has excellent initial adhesive strength and high-speed coating properties, and is easy to handle.

B. Conventional technology Conventionally, paper adhesives include starch, casein, gelatin,
Natural thickening agents such as gum arabic, sodium alginate, and guar gum, calphoquinol methylcellulose (hereinafter referred to as CMC)
(abbreviated as ), oxidized starch, methyl cellulose, and other processing glues; acrylic emulsions, polyacetic acid emulsions,
Synthetic resin emulsion such as ethylene-vinyl acetate copolymer emulsion and SBR latex; average degree of polymerization 40
Adhesives containing polyvinyl alcohol (hereinafter abbreviated as PVA) or the like as a main component are widely used alone or as a composition thereof.

However, natural glue and its processed glue lack adhesive strength, the viscosity stability of the adhesive solution is insufficient, there are problems such as spoilage, and it is difficult to obtain products with consistent quality over a long period of time. There are some drawbacks such as:

On the other hand, although emulsions and latex have excellent adhesive strength, they lack mechanical stability, lack initial tack, especially wet tack, and have other problems such as poor creep resistance and a tendency to form skin on the surface. I have a lot of things to hold on to.

In recent years, in order to reduce product costs and improve productivity, roll coating speeds for adhesives have become faster, and initial adhesive strength has become more important.

However, conventional adhesives based on natural glue, processed glue, and PVA resin lack initial adhesive strength, so when applying adhesive to paper at high speed, the pressing time is If the adhesive is not kept for a long time, there is a problem that the adhesive part of the paper will peel off.Also, although synthetic resin emulsion adhesives have good initial adhesive strength, they are expensive and have a tendency to fly away at high speeds. There were some problems with this, and I was not completely satisfied with it.

C1 Problems to be Solved by the Invention The object of the present invention is to provide a composition and an adhesive that do not have any of the above-mentioned problems.

Means for Solving Problems D and R As a result of intensive studies to solve the above problems, the inventors found that the average degree of polymerization (hereinafter abbreviated as degree of polymerization) was 4000.
The present invention has been completed by discovering a composition and an adhesive comprising the above p v p (A).

The present invention will be explained in detail below.

The degree of polymerization of PVA (A) in the present invention is required to be 4,000 or more, preferably 8,000 or more, more preferably 10,000 or more. There is no particular restriction on the upper limit of the degree of polymerization, but it is preferably about 25,000 or less. In addition, the degree of polymerization of P V A (A) of the present invention is
It is expressed as the viscosity average degree of polymerization determined from the following formula from the intrinsic viscosity measured at 30° C. in acetone for polyvinyl acetate obtained by re-acetating a VA polymer.

P − ([η]X 1000/7.94)"" ・!
] When the degree of polymerization of PVA (A) is 25,000 or more,
If a pressure heating device such as an autoclave is not used, workability may be reduced, such as failure to dissolve. If the degree of polymerization is less than 4000, the initial adhesive strength will be low, which is not preferable. p with a degree of polymerization of 4000 or more used in the present invention
v p, (A) is obtained by polymerizing vinyl ester and saponifying it.

Specific examples of vinyl esters include vinyl formate, vinyl acetate, vinyl butyrate, vinyl pivalate, vinyl persate, etc. Among these, vinyl acetate is industrially preferred. There is no particular restriction on the degree of saponification of the obtained PVA, but it is preferably 50 mol% or more, and 65% by mole or more.
~95 mol% is preferred. If the degree of saponification is lower than 50 mol%, water solubility tends to decrease and adhesive strength tends to decrease, which is not preferable. Moreover, if the degree of saponification is higher than 98 mol%, the solubility may be lowered or the workability may be lowered, which may be undesirable.

There is no problem in including the PVA of the present invention or a small amount of a copolymer component in the molecule as long as it does not interfere with the gist of the present invention. Specific examples of such copolymer components include carboxyl group-containing monomers or salts thereof such as (meth)acrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, and itaconic acid, acrylamide-2- Sulfonic acid group-containing monomers such as sodium methylpropanesulfonate, sodium allylsulfonate, and sodium vinylsulfonate, (
Examples include anionic or cationic monomers such as quaternary ammonium salt-containing monomers such as meth)acrylamide-propyl-trimethylammonium chloride.

However, when the above-mentioned ionic monomers are copolymerized, there is a tendency for a decrease in water resistance after adhesion and the occurrence of curling at high humidity, so a high degree of modification is not recommended. Undesirable. Therefore, it is desirable that the content of such monomers be 3 mol% or less.

Specific examples of copolymer components other than those listed above include α-olefins such as ethylene and propylene, (meth)acrylic acid esters, acrylamide, dimethylacrylamide,
Amide group-containing monomers such as N-methylolacrylamide, alkyl vinyl ethers, silyl group-containing monomers such as trimethquin vinylsilane, hydroxyl group-containing monomers such as allyl alcohol, dimethylallyl alcohol, isopropenyl alcohol, allyl acetate, Examples include acetyl group-containing monomers such as dimethylallyl acetate and isopropenyl acetate, halogen monomers such as vinyl chloride and vinylidene chloride, and aromatic monomers such as styrene.

The composition of the present invention has a polymerization degree of 4000 or more p VA (
A), and other ingredients include filler (B), natural glue, processed glue, synthetic resin emulsion, and PVA with a polymerization degree of less than 4000.
It is preferable to use one or more types of trees 1i (C) selected from the following, individually or in combination.

As the filler (B), organic fillers and inorganic fillers are used, and inorganic fillers are particularly preferred. Among inorganic fillers, clays such as kaolinite, halloysite, pyroferrite, and sericite; heavy, light, and surface-treated calcium carbonate; aluminum hydroxide; gypsum; talc; mica; titanium oxide, etc. 11 or more is preferable, and clay is the most preferable among them. It is desirable that these fillers (B) have an average particle size of 10μ or less, and when made into a composition with PVA, a uniform slurry solution can be provided without blocking or settling to the bottom. is necessary.

The blending ratio of component (A) and component (B) is component (A) 1
00 parts by weight, component (B) is preferably 10 to 500 parts by weight, more preferably 50 to 200 parts by weight.

Compositions and adhesives that do not contain fillers (B), especially inorganic fillers, are not only expensive, but also slow to develop initial adhesion, have low equilibrium adhesion, and have poor water resistance, moisture resistance, or no gain at all. There are drawbacks such as the inability to absorb heat, which can lead to poor shear stress and creep resistance.

If the ratio of filler (B) is smaller than the above range, the above drawbacks are likely to occur, and conversely, if it is too large than the above range,
This may lead to deterioration of the fluidity of the composition and a decrease in adhesive strength.

As the one or more resins (C) selected from natural sizing agents, processed sizing agents, synthetic resin emulsions, and PVA with an average degree of polymerization of less than 4000, those described in the prior art section are preferably used.

The blending ratio of component (A) and component (C) is component (A) 1
00 parts by weight, component (C) is 100 to 10,000 parts by weight.
The amount is preferably 1000 to 7000 parts by weight, and more preferably 1000 to 7000 parts by weight.

In the case of a composition consisting of component (A), component (B) and component (C), the blending ratio is 100 parts by weight of component (A) to -10,000 parts by weight of component (C), and It is preferable that the blending ratio of component (B) to 100 parts of the total amount of component (A) and component (C) is 10 to 500 parts by weight.

The composition consisting of PVA (A) of the present invention includes: metal salts of phosphoric acid compounds such as sodium polyphosphate and sodium hexametaphosphate; dispersions of inorganic substances such as water glass; polyacrylic acid and its salts; sodium alginate; By using in combination with anionic polymer compounds such as olefin-maleic anhydride copolymers or metal salts thereof; nonionic surfactants such as ethylene oxide adducts of higher alcohols and copolymers of ethylene oxide and propylene oxide. , the fluidity is further improved.

Further, polyethylene oxide, various antifoaming agents, preservatives, antifungal agents, coloring pigments, deodorants, fragrances, and the like can be added as necessary. Further, in order to improve adhesive strength, a water-soluble boron compound such as boric acid, borax, glycerin, or boric acid ester of polyhydric alcohol such as polyethylene glycol can be added. However, if the amount added is too large, it will adversely affect high-speed coating properties, so it is appropriate to add less than 10 parts by weight per 100 parts by weight of the PVA (A) of the present invention.

Next, I will explain about the zero-based adhesion agent.

The adhesive of the present invention is a water-based adhesive that is made of the above-mentioned composition or polyvinyl alcohol with a degree of polymerization of 4000 or more, and is used as an adhesive for paper, wood, plastic, cloth, etc., and is particularly excellent as an adhesive for paper. It is.

Although the adhesive of the present invention is a water-based adhesive, alcohols such as methanol, ethylene glycol, and glycerin, and organic solvents such as cellosolves are added in order to impart flexibility to the antifreeze agent and adhesive phase. May be added.

There are no particular restrictions on how to prepare these adhesives, but
Examples include PVA (A), filler (B), starch (
C), if necessary, a method of adding other additives into the water while stirring, or additives,
An example of this method is to prepare a slurry by adding the filler (B), PVA (A), and starch (C) to water while stirring them one after another.

The adhesive can be prepared either batchwise or continuously, and it can be heated by any heating method such as a heating method in which steam is directly blown into the slurry liquid in a jet kutsuker or a haiseidan, or an indirect heating method using a jacket. It may be adjusted by dissolving it.

The viscosity of the adhesive of the present invention varies depending on the application, but if high-speed application is intended, the appropriate viscosity at the lamination temperature is 100 to 8000 centivoise in B type thickness. range.

E. Examples Hereinafter, the present invention will be explained in more detail with examples.
The present invention is not limited in any way by these Examples. In the following, [parts] and [%] mean parts by weight and % by weight, respectively, unless otherwise specified.

The polymerization degree and saponification degree of PVA used in Examples 1 to 7 and Comparative Examples 1 to 4 are shown in Table 1 below.

PV used in Examples 8 to 14 and Comparative Examples 5 to 9
The polymerization degree and saponification degree of A are shown in Table 2 below.

Further, in the following examples and comparative examples, fillers 1 to 3 when using fillers are as follows.

Filler 1 + ASP-200 (manufactured by Engelhardt)
, average particle size 0.55 μm, kaolinite clay filler 2: Huber-900 (manufactured by Huber), average particle size 0.6 μm, kaolinite clay filler 3. Whiten P-30 (manufactured by Shiraishi Kogyo Co., Ltd.), average particle size 1.75μ
The preparation of the MW carnoum carbonate composition and adhesive is as follows:
A mixture of V A (A) and filler (B) in powder form was poured into water with stirring, and the mixture was heated to 95° C. and dissolved.

Evaluation of high-speed coating properties and initial adhesion were performed by the following methods. The results are shown in Tables 3 and 4.

[High speed coating] A test was conducted using the three rolls shown in FIG.

The surface speed of the roll (1) was set at 120 m/min, and the roll (
The following test was conducted by adjusting the surface speed of Ili) to 60 m/lin and adding an adhesive liquid between roll (II) and roll (1111).

(1) Check to see if droplets of glue are flying out between jumping roll (1) and roll (II).

(2) Roll transferability: Check whether the size liquid is evenly applied to the roll (1).

(3) Foamability: Check how much the size liquid absorbs foam. Measure the weight per 100 mj volume of #R liquid before and after the test, and calculate the weight ratio.

Foaming property (%) = (weight after test / weight before test) x 10
0(4) Stringiness: Check the stringiness of the size liquid between roll (1) and roll (It).

[Initial adhesion] 20sm x 100m of base paperboard with a basis weight of 412g/m"
Cut into pieces of m size and apply 50g/g of adhesive on one side.
After coating with a bar coater so that the thickness is 30 m" (wet), another base paper is laminated and 30 g/an" of pressure is applied.
The adhesive force after pressing for ~120 seconds was evaluated by measuring the peel strength.

Implementation PI-7 Example-! 100 parts of [PVA-4] used in Example 2, 0.67 parts of sodium alginate (Kelgin QL), 0.67 parts of antifoaming agent, and [Filler 2 used in Example-2]
] 199 parts of the powder was mixed together, added to 1333 parts of water with stirring, and heated and dissolved at 96°C. Type B viscosity at 30°C is 2490 centipoise, solids concentration is 19
．． It was 8%.

An adhesive bonding test was conducted between a single-sided E-flute cardboard box with a width of 90 cm and a length of 145 cm and a printed paperboard. The coating speed was 80 sheets per minute, and the adhesive transfer roll speed was 120 m/min.

A certain area of black paper was placed behind the transfer roll, and the flying paste was observed. Adhesive was applied to one-sided cardboard, the paperboard was bonded to the cardboard, and the bonding was completed by pressing for 1 minute.

As a result of a 10-minute continuous adhesion test, there were hardly any traces of jumping on the black paper, the fluidity of the adhesive was good, and the high-speed coating property was excellent. Furthermore, when the paperboard was peeled off by hand after pressing, the paper broke at the adhesive layer, and the adhesiveness was also good.

Comparative Example-4 Example 7 except that [:PVA-3] used in Comparative Example 1 was used instead of [PVA-4] used in Example-7.
A continuous bonding test for 10 minutes was conducted in the same manner as above. There was a lot of glue on the black paper, indicating that the jumping was not good.

The transfer roll also showed a strong striped pattern, and the adhesive part also contained a lot of bubbles and was in an unstable state.

Although the adhesion was generally good, curling occurred after adhesion and before the drying process. Considering these circumstances, it is necessary to bond continuously at this speed.Example-14 100 parts of [PVA91, [P
VA-8] 77,700 parts Antifoaming agent 40 parts and [Filler 2] used in Example-8 11,000f!
l! The mixture was mixed as a powder, poured into 80,000 m of water with stirring, and dissolved by heating at 96°C. The B-type viscosity at 30° C. was 2090 centivoids, and the solid cedar content was 19.8%.

An adhesive bonding test was conducted between a single-sided E-flute cardboard box with a width of 9 rJc* and a length of 145 cm and a printed paperboard.

The coating speed was 80 sheets per minute, and the adhesive transfer roll speed was 120 m/min.

A certain area of black paper was placed at the rear of the transfer roll, and the state of scattering of the nodding paste was observed. Adhesive was applied to one-sided cardboard, the paperboard was bonded to the cardboard, and the bonding was completed by pressing for 1 minute.

As a result of a 10-minute continuous adhesion test, there was hardly any evidence of jumping on the black paper, the fluidity of the adhesive was good, and high-speed application was excellent. , paper breakage occurred in the adhesive layer, but the adhesiveness was good and f2.

Comparative Example-9 Same as Example-14 except that CMC used in Comparative Example 7 was used instead of [PVA-9] used in Example-14, and oxidized starch was used instead of [PVA-8]. to 1
A continuous bonding test was conducted for 0 minutes. There was a lot of glue on the black paper, indicating that the jumping was not good.

The transfer roll also showed a striped pattern, and the adhesive part also contained a lot of bubbles and was in an unstable state.

Adhesion strength was low and many peeled off after adhesion. Further, curling occurred before the drying process was started after adhesion. Considering these circumstances, continuous bonding was impossible.

Effects of the F1 Invention As is clear from the above examples, the adhesive made of the composition of the present invention is particularly excellent as an adhesive for paper, has particularly high initial adhesive strength, and is suitable for high-speed coating. It has extremely high industrial value.

[Brief explanation of drawings]

FIG. 1 shows the rotational directions of roll (1), roll (II), and roll (1) used in the evaluation of high-speed coating properties, and the relative positional relationship of the adhesive. ...Rubber roll (1) 2 ...Rubber roll (II) 3 ...Metal roll (I[l) 4 ...Adhesive Figure 1

Claims (8)

[Claims] (1) A composition comprising polyvinyl alcohol (A) having an average degree of polymerization of 4000 or more and a filler (B). (2) The composition according to claim 1, wherein the proportion of component (B) is 10 to 500 parts by weight relative to 100 parts by weight of component (A). (3) A composition comprising the polyvinyl alcohol (A) according to claim 1 and one or more resins (C) selected from natural sizing agents, processed sizing agents, synthetic resin emulsions, and polyvinyl alcohols having an average degree of polymerization of less than 4000. . (4) The composition according to claim 3, wherein the proportion of component (C) is 100 to 10,000 parts by weight relative to 100 parts by weight of component (A). (5) A composition comprising the polyvinyl alcohol (A) according to claim 1, the filler (B), and the resin (C) according to claim 3. (6) The blending ratio of component (C) is 100 to 10,000 parts by weight per 100 parts by weight of component (A), and the ratio of component (B) to 100 parts by weight of the total amount of component (A) and component (C) is 100 to 10,000 parts by weight. ) is blended in a proportion of 10 to 500 parts by weight.
Compositions as described. (7) An adhesive comprising the composition according to any one of claims 1 to 6. (8) An adhesive comprising the polyvinyl alcohol (A) according to claim 1.