JPH0673259A - Polyvinyl alcohol-starch derivative composition and its use - Google Patents

Abstract

PURPOSE:To obtain the subject compsn. which has characteristics inherent in a polyvinyl alcohol resin, such as a stable soln. viscosity and high film strengths, by compounding a polyvinyl alcohol resin with a starch deriv. obtd. by grafting a specific monomer onto starch. CONSTITUTION:The objective compsn. comprises a polyvinyl alcohol resin and a starch deriv. which is obtd. by grafting 1-20 pts.wt. at least one monomer selected from the group consisting of a carboxylic acid, a sulfonic acid, an amine, a quaternary ammonium salt, an amide, a vinyl ester, and vinylpyrrolidone onto 100 pts.wt. starch-based compound which has a viscosity of a 10wt.% aq. soln. of 1,000cP or lower. The compounding ratio of the resin to the starch deriv. is pref. (100:1) to (100:200). The compsn. gives a biodegradable film, an adhesive compsn. excellent in high-speed application and initial adhesiveness, a barrier agent for paper excellent in high-speed application, etc.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a film-forming composition comprising a polyvinyl alcohol resin and a starch resin, which has good compatibility and is capable of obtaining an aqueous solution which does not phase-separate even after standing for a long time, and its use, in particular, The present invention relates to a biodegradable film using the composition, an adhesive composition excellent in high-speed coating property, a barrier agent for paper and a surface sizing agent for paper, and a method for producing coated paper.

[0002]

2. Description of the Related Art Polyvinyl alcohol resin (hereinafter PV
A) may be abbreviated as A), since the stability of the aqueous solution is good and the strength of the obtained film is much higher than that of other water-soluble substances. Widely used as processing agents and adhesives. When PVA is used, it has already been widely practiced to blend a starch and a polyvinyl alcohol resin for the purpose of reducing the total cost of the composition, but there have been many problems. For example, in the warp sizing agent, the strength of the obtained film is significantly reduced depending on the type of starch to be blended, so that troubles during weaving may increase, or the warp sizing agent aqueous solution may be stored without stirring or under weak stirring. If it is left, the aqueous solution may be phase-separated into a starch-based phase and a PVA-based phase, which may cause a problem that stable gluing cannot be performed.

On the other hand, in recent years, a biodegradable film which is naturally biodegraded by simply leaving it outdoors and morphologically disintegrates rarely contaminates the natural world, and is therefore being studied as an environmentally friendly film. As such a film, conventionally, for the purpose of morphologically disintegrating the film by starch biodegradation, a film in which a thermoplastic resin has a biodegradable starch or the like has been studied, but with a thermoplastic resin, There is a problem that the compatibility of starch is poor, the strength of the obtained film is remarkably lowered as compared with the thermoplastic resin, and further it takes time to disintegrate the thermoplastic resin which is remarkably inferior in biodegradability as compared with the starch.
In addition, attempts have been made to make biodegradable films only with polymers derived from organisms such as starch, but polymers derived from organisms are generally fragile, and there is a problem that it is difficult to form a tough film. Further, in order to improve the fragility of a film made of a polymer derived from a living organism such as starch, it has been attempted to blend a polyvinyl alcohol resin which is a water-soluble synthetic polymer, but both of them are essentially Since the compatibility is not good, the stability of the aqueous solution of the film-forming stock solution is poor, and there are various handling problems such as phase separation between the two and the viscosity of the aqueous solution changes with time. No satisfactory physical properties of the obtained film have been found.

As the adhesive composition, a water-based adhesive has hitherto been widely used as an adhesive for paper such as corrugated board, paperboard, paper tube and interleaf paper. The main components of these adhesives are synthetic emulsions composed of polymers of monomers such as vinyl acetate, acrylic ester, ethylene-vinyl acetate; styrene-butadiene rubber (SBR),
Latex of acrylonitrile-butadiene rubber (NBR), isoprene rubber (IR), natural rubber (NR), etc .; PVA, starch, modified starch, modified cellulose,
Examples include synthetic or natural pastes such as casein and gelatin. Further, urea resin, urea-melamine resin, phenol resin, etc. are mainly used as an adhesive for wood for plywood or plywood secondary processing. Many of these wood adhesives are inexpensive, have excellent initial adhesive strength, and have good water resistance. However, recently, the coating speed of paper adhesives and wood adhesives has been increasing. For example, an adhesive for interleaving paper has been conventionally applied at a speed of 60 to 70 m per minute, but recently, it is often applied at a speed of 100 to 150 m per minute. Excellent high speed coating and initial adhesion are required.

Further, many paper adhesives are inexpensive and have excellent initial adhesive strength, but few have excellent high-speed coating properties and initial adhesive properties at the same time. Synthetic emulsions and latexes have moderate coatability, but have low strain resistance when immersed in hot water or hot water, have problems with heat creep, and have sufficient initial adhesion. Absent. In addition, formalin-based adhesives such as urea resins and urea-melamine resins that are commonly used as adhesives for wood are caused by the residual formaldehyde (hereinafter abbreviated as formalin) in the adhesives, which causes work during plywood manufacturing. The release of formalin from furniture and houses made of plywood using it has become a big problem recently, and attempts have been made to reduce the release of formalin from these resins. . For example, there have been studies such as reducing the molar ratio of formalin to urea and melamine, and adding an absorber of free formalin, but essentially, formalin cannot be completely eliminated, and it is not completely safe. The current situation is that I cannot say that. It is said that these formalin adhesives have problems in weather resistance and durability. On the other hand, PVA-based adhesives are widely used as adhesives because they have good adhesiveness and have some water resistance. However, PVA-based adhesives have a problem in high-speed coating properties, and streaking occurs on rolls during roll coating, resulting in coating unevenness, threading of adhesives between rolls, adhesive skipping, foaming, etc. Therefore, high speed coating has a limit. Natural sizing agents such as starch and processed cellulose generally have good coatability, but initial adhesion,
It has problems with water resistance and durability, and is not used alone except in special cases. Among natural sizing agents, casein and gelatin are expensive and have problems in quality variation and storability. Therefore, they are only used in special fields such as labels and black inks as adhesives. A mixture of PVA and starch is often used to reduce the cost of the adhesive, but both the high-speed coating property and the initial adhesive property are insufficient, and the defects of both are often left. .

[0006] As for the barrier agent for paper, it has been conventional to use P
VA is used as a barrier agent. PVA is a clear coating agent or pigment coating for improving surface properties of paper such as surface strength, smoothness, gloss or barrier property (a property of lowering absorption and permeability of air, oil or organic solvent). It is also widely used as a binder in, and has excellent properties that cannot be followed by other water-soluble polymers in film-forming properties and film strength, so when producing paper with barrier properties,
Widely used as a barrier agent. However, in recent years, it has been required to improve the productivity of barrier papers, and in particular, the number of cases where a barrier agent is applied on-machine by a gate roll coater (hereinafter sometimes abbreviated as GRC) is increasing. When performing on-machine coating by GRC, it is required to coat the barrier agent at a high speed equivalent to the papermaking speed. In the case of the conventional PVA, when the coating speed is increased or the liquid concentration is increased, the coating property is deteriorated, and particularly the liquid film on the roll becomes streaky, and as a result, it is directly transferred onto the paper. There is a drawback that uneven coating and scattering of the coating liquid from the roll become remarkable.

Surface sizing agents for paper have heretofore been used as surface sizing agents for the surface sizing of paper for the purpose of improving the surface strength of the paper and improving printability, such as starch, polyacrylamide or PVA. Is used. Compared to other polymers, PVA is superior as a surface sizing agent for paper in that it has improved surface strength and printability, but it is more effective in improving coatability and paper surface strength. At present, it is often difficult to measure with conventional PVA. recent years,
In particular, due to a lack of wood resources, the use of hardwood has increased in place of high-quality softwood, and there is a problem that conduit cells, which are contained in large amounts in hardwood, peel off during printing and give white spots to the printed image. ing. In order to prevent the inconvenient phenomenon and improve the surface strength of the paper, it was necessary to apply a large amount of sizing agent. In the conventional PVA, if the concentration of the coating liquid is increased in order to increase the coating amount, there is a problem that the coatability, especially the high-speed coatability deteriorates. In the case of surface sizing of mass-produced paper such as newspapers, on-machine coating with a gate roll coater (hereinafter sometimes abbreviated as GRC) is increasing in order to increase productivity. When performing on-machine coating with GRC, it is required to apply the sizing agent at a high speed equivalent to the papermaking speed, but with conventional PVA, increasing the coating speed enables coating even at low concentrations. There is a drawback that the property is poor and that the coating liquid is particularly scattered from the roll.

[0008]

In view of such circumstances, the present invention provides PV having characteristics of PVA such as good stability of the aqueous solution and high strength of the obtained film.
The object is to provide a composition comprising A and a starch compound. Another object of the present invention is to provide a film which is tough and has a property of being rapidly biodegraded when left outdoors. Another object of the present invention is to provide an adhesive composition having excellent high-speed coating property and initial adhesive property. Another object of the present invention is to provide a barrier agent for paper, which is coated on the surface of the paper to impart a barrier property to the paper and which is superior in high-speed coating property to conventional barrier agents. Furthermore, the present invention provides a PV which has a high surface strength of coated paper and good printability.
It is also an object of the present invention to provide a surface sizing agent for paper which does not impair the characteristics of A and is superior in high-speed coating property to conventional surface sizing agents. Another object of the present invention is to provide a method for producing coated paper using the surface sizing agent for paper.

[0009]

In order to solve the above-mentioned problems, the inventors of the present invention have PVA and starch-based compounds having the properties of PVA such as good stability of aqueous solution and high strength of the obtained film. As a result of earnestly studying the composition consisting of the polyvinyl alcohol resin (A) and a carboxyl group-containing monomer, a sulfonic acid group-containing monomer, an amino group-containing monomer, a quaternary ammonium group-containing monomer, 10% by weight obtained by graft-polymerizing 1 to 100 parts by weight of at least one kind of monomer selected from amide group-containing monomer, vinyl ester and vinylpyrrolidone
Of a starch-based compound (B) having an aqueous solution viscosity of 1000 cP or less (hereinafter abbreviated as starch-based compound (B)), which is useful as a film having excellent elongation and biodegradability. I found something.

The present inventors have further found that an adhesive composition comprising the above composition has a high-speed coating property and an initial adhesive property which are significantly superior to those of a conventional paper adhesive or wood adhesive. It was The reason for this has not been fully clarified, but since the compatibility between the polyvinyl alcohol-based resin (A) and the starch-based compound (B) is good, the obtained coating film is tough and the adhesion immediately after the adhesion is achieved. It is presumed that since the viscosity of the agent increases rapidly, the initial adhesive strength increases, and the good coatability inherent in starch develops.

The present inventors have further found that the paper barrier agent comprising the above composition has both good barrier properties and good coating properties. The reason for this has not been fully clarified, but it is presumed that it is due to the good compatibility of the aqueous solutions of the polyvinyl alcohol resin (A) and the starch compound (B).

Further, the present inventors have found that the surface sizing agent for paper comprising the above composition has excellent coatability. The reason for this has not been fully clarified, but the aqueous solution of the blend of the polyvinyl alcohol resin (A) and the starch compound (B) maintains a uniform state when no shearing force is applied. However, when the aqueous solution is subjected to high shearing or stretching behavior such as during high-speed coating, the aqueous solution undergoes phase separation, and it is presumed that the scattering of the coating solution from the roll is reduced. Thus, the present invention has been completed.

That is, the present invention provides (1) a polyvinyl alcohol resin (A) and a starch structure portion 100.
From carboxyl group-containing monomer, sulfonic acid group-containing monomer, amino group-containing monomer, quaternary ammonium salt group-containing monomer, amide group-containing monomer, vinyl ester and vinylpyrrolidone relative to parts by weight A composition comprising a starch compound (B) having a 10% by weight aqueous solution viscosity of 1000 cP or less obtained by graft-polymerizing 1 to 200 parts by weight of at least one selected monomer, (2) above (1) (3) A film comprising the composition according to (1), (3) an adhesive composition comprising the composition according to (1) above, (4) a barrier agent for paper comprising the composition according to (1) above, (5) above ( A surface sizing agent for paper comprising the composition according to 1), and (6)
A method for producing a coated paper, which comprises coating the surface sizing agent for paper according to the above (5) with a roll coater at a speed of 300 m / min or more.

The polyvinyl alcohol resin (A) used in the present invention is generally a polyvinyl acetate obtained by polymerizing or copolymerizing vinyl acetate by a known polymerization method such as bulk, solution, suspension and emulsification. It can be obtained by saponification by a known method. However, in the case of the adhesive composition, it is not limited to polyvinyl acetate, polyvinyl formate, vinyl propionate, vinyl butyrate, vinyl versatate, polyvinyl pivalate obtained from the above known polymerization method from vinyl esters such as vinyl pivalate. Although vinyl acetate may be used, vinyl acetate, which is industrially inexpensively produced, is preferably used.

The degree of saponification of the polyvinyl alcohol resin (A) is preferably 60 to 100 mol%, 70 to 9
9.9 mol% is more preferable, and 80-99.5 mol% is still more preferable. When the saponification degree is lower than 60 mol%, the water solubility of the polyvinyl alcohol resin (A) is lowered, or the starch compound (B) obtained by graft-polymerizing the polyvinyl alcohol resin (A) and the carboxylic acid-containing olefin monomer. It is not preferable because the compatibility with the compound tends to decrease.

The degree of polymerization of the polyvinyl alcohol resin (A) is generally preferably 200 or more, more preferably 300 to 20,000 in the case of a composition or film, and 500 to 1
0000 is even more preferable. In the case of an adhesive composition, 500 to 5000 is more preferable. In the case of a barrier agent for paper, 200 to 5000 is preferable, and 300 to 30
00 is more preferable, and 700 to 2000 is even more preferable. 200 to 5 for surface sizing agents for paper
000 is preferable, 300 to 3000 is more preferable,
Even more preferably 700-2500. When the polymerization degree of the polyvinyl alcohol resin (A) is less than 200, the strength of the obtained film is lowered in the case of the composition or film, and the initial adhesiveness and the equilibrium adhesiveness are lowered in the case of the adhesive composition. In the case of a barrier agent for paper, the degree of improvement in the barrier property of the paper becomes small, and in the case of a surface sizing agent for paper, the surface strength of the paper is hardly improved, which is not preferable.
Further, in the case of a barrier agent for paper and a surface sizing agent for paper, when the degree of polymerization exceeds 5,000, the coating property is deteriorated, streaks are generated on the roll, and scattering of the coating liquid from the roll is increased.

The polyvinyl alcohol resin (A) used in the present invention may be a blend of two or more different polyvinyl alcohol resins. However, in the case of a surface sizing agent for paper, it is preferable that the polyvinyl alcohol-based resins to be blended have similar polymerization degrees in terms of scattering of the coating liquid from the roll.

Here, polyvinyl alcohol resin (A)
The degree of polymerization is a viscosity average degree of polymerization obtained by a usual method from the viscosity of an aqueous solution of the completely saponified polyvinyl alcohol resin.

The polyvinyl alcohol resin (A) used in the present invention may be copolymerized with other monomers,
Moreover, what modified the polymer terminal using the chain transfer agent can also be used. The ethylenic monomer copolymerizable with vinyl ester is not particularly limited as long as it is copolymerizable with vinyl ester, and examples thereof include α-olefins such as ethylene, propylene, n-butene, isobutene and 1-hexadecene. Carboxylic acid-containing monomers such as (meth) acrylic acid, fumaric acid, itaconic acid, crotonic acid, maleic acid, and maleic anhydride, and salts thereof, methyl (meth) acrylate, ethyl (meth) acrylate, (meth) (Meth) acrylic acid esters such as n-butyl acrylate, 2-hydroxyethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, dimethyl fumarate, dimethyl itaconate, malein Esters of dimethyl acid, monomethyl maleate, dimethyl crotonate, etc., methyl vinyl Vinyl ethers such as ether, ethyl vinyl ether, butyl vinyl ether, lauryl vinyl ether, stearyl vinyl ether, and sulfonic acid group-containing monomers such as vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, and 2-acrylamido-2-methylpropane sulfonic acid. And salts thereof, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, Nt-butoxy (meth) acrylamide, N
Amide group-containing monomers such as -t-octyl (meth) acrylamide and N-vinylpyrrolidone, amino group-containing monomers such as dimethylaminoethyl (meth) acrylamide,
Quaternary ammonium salt-containing monomers such as (meth) acrylamidopropyltrimethylammonium chloride, vinylhydroxysilane, silyl group-containing monomers such as (meth) acrylic acid-3-trimethoxysilylpropyl, allyl alcohol, dimethylallyl alcohol , A hydroxyl group-containing monomer such as isopropenyl alcohol, allyl acetate,
Examples include acetyl group-containing monomers such as dimethylallyl acetate and isopropenyl acetate.

The starch compound (B) used in the present invention
As, for 100 parts by weight of the starch structure portion, a carboxyl group-containing monomer, a sulfonic acid group-containing monomer, an amino group-containing monomer, a quaternary ammonium salt group-containing monomer,
1 to 2 are graft moieties (hereinafter abbreviated as graft moieties) composed of at least one monomer selected from an amide group-containing monomer, vinyl ester and vinylpyrrolidone.
00 parts by weight, preferably 1 to 100 parts by weight, 5 to
50 parts by weight is more preferable, and 10 to 30 parts by weight is even more preferable. Those having less than 1 part by weight of graft part per 100 parts by weight of starch structure part are generally
If the paste solution is stored without stirring or under weak stirring, phase separation is likely to occur and cast film formation in a film tends to be difficult. Especially for paper barrier agents,
The high-speed coating property of the sizing agent aqueous solution, in particular, the liquid film on the roll becomes streak, and the uneven coating due to the transfer of the sizing agent on the paper as it is and the scattering of the sizing agent aqueous solution from the roll are likely to occur. Further, if the aqueous sizing agent solution is stored without stirring or under weak stirring, phase separation tends to occur easily. Starch structure 10
The effect of the present invention does not change even if the grafted portion is more than 100 parts by weight with respect to 0 parts by weight, but the higher the degree of starch grafting, the higher the cost.

The monomers for graft polymerization of the graft portion of the starch compound (B) used in the present invention include carboxyl group-containing monomers, sulfonic acid group-containing monomers, amino group-containing monomers, It is at least one kind of monomer selected from a quaternary ammonium salt group-containing monomer, an amide group-containing monomer, a vinyl ester and vinylpyrrolidone. Examples of the carboxyl group-containing monomer include (meth) acrylic acid, fumaric acid, itaconic acid, crotonic acid, maleic acid or its esters, and maleic anhydride. Examples of the sulfonic acid group-containing monomer include vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid and the like, and salts thereof. As the amino group-containing monomer, in addition to (meth) acrylamidopropyltrimethylamine and the like, N
-Vinylacetamide, N-vinylmethylacetamide, N-vinylformamide, and other monomers that can be converted into amino groups by saponifying the amide groups after graft polymerization are included. Examples of the quaternary ammonium salt group-containing monomer include (meth) acrylamidopropyltrimethylammonium chloride. As the amide group-containing monomer, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-methylol (meth)
Examples thereof include acrylamide, Nt-butoxy (meth) acrylamide, Nt-octyl (meth) acrylamide and the like. Examples of the vinyl ester include vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl versatate, vinyl pivalate, etc., which are completely saponified or partially saponified by saponification after graft polymerization of these monomers. A starch compound (B) having a graft portion composed of alcohol can also be used. Examples of vinylpyrrolidone include N-vinylpyrrolidone. These monomers are not limited to the above-exemplified monomers. Further, these monomers may be used as a mixture of two or more kinds.

The carboxylic acid or sulfonic acid introduced into the starch by graft polymerization may be partially neutralized with an alkali. The degree of neutralization of these acids is not particularly limited, but is preferably 0 to 90 mol%,
80 mol% is more preferable, and 0 to 60 mol% is even more preferable.

Raw starch before graft polymerization of the above monomers used in the present invention includes raw starch, oxidized starch, acid-treated starch, processed starch such as etherified starch, esterified starch and cross-linked starch. Either can be used.

The starch compound (B) used in the present invention
The viscosity of the aqueous solution of is not particularly limited, but is generally 120
The viscosity of a 10% by weight aqueous solution dissolved under gelatinization conditions at 10 ° C for 10 minutes at 90 ° C and 60 rpm using a BL type viscometer is preferably 1000 cP or less, more preferably 500 cP or less, and even more preferably 100 cP or less. preferable.
Further, particularly in the case of a barrier agent for paper and a surface sizing agent for paper, the viscosity is preferably 1 to 1000 cP,
500 cP is more preferable, and 2-100 cP is even more preferable.

The mixing ratio of the polyvinyl alcohol resin (A) and the starch compound (B) in the present invention is generally 1 to 200 starch compounds (B) per 100 parts by weight of the polyvinyl alcohol resin (A). Parts by weight is preferable, 2 to 100 parts by weight is more preferable, and 5 to 50 parts by weight is even more preferable. Especially for film, 5
˜150 parts by weight is more preferred, and 10 to 100 parts by weight is even more preferred. Starch compound (B) based on 100 parts by weight of polyvinyl alcohol resin (A)
Is more than 200 parts by weight, the resulting film strength is lowered, the initial adhesive strength of the adhesive composition is lowered, the barrier property of the paper is lowered, and the surface strength of the coated paper is lowered. When the amount of the starch compound (B) is less than 1 part by weight based on 100 parts by weight of the polyvinyl alcohol resin (A), the effect of blending such as the cost reduction effect is deteriorated and the biodegradability of the film is deteriorated. Also, in the case of a paper barrier agent and a paper surface sizing agent, the fluidity of the coating liquid during high-speed coating, especially the liquid film on the roll becomes streaky, and it is directly transferred to the paper. The unevenness of the coating due to the coating and the scattering of the coating liquid from the roll increase.

The concentration of the coating liquid of the barrier agent for paper of the present invention is preferably 0.1 to 30% by weight, more preferably 0.2 to 20% by weight, still more preferably 0.5 to 15% by weight. When the concentration of the coating liquid is less than 0.1% by weight, the barrier property of the paper is low. Concentration of coating liquid is 30% by weight
When it is higher, the coatability is poor, and particularly the scattering of the coating liquid from the roll is increased, and the amount of the barrier agent attached to the paper is too large during normal coating, which is not economical.

The concentration of the surface sizing agent for paper of the present invention is preferably 0.1 to 30% by weight, and 0.5 to 20% by weight.
Is more preferable. If the concentration is less than 0.1% by weight,
The surface strength of the paper is hardly improved. Concentration is 30% by weight
When it is higher, the coatability is poor, and particularly the scattering of the coating liquid from the roll becomes significant. Also, the concentration is 30% by weight
If it is higher, the amount of the sizing agent adhered to the paper during ordinary coating becomes too large, which is not economical.

The present invention comprises a polyvinyl alcohol resin (A) and a starch compound (B), but other starch, as long as the effects of the present invention are not impaired,
CMC, inorganic pigments, organic pigments, other auxiliaries (eg defoaming agents,
Antistatic agents, antifungal agents, antioxidants, ultraviolet absorbers, lubricants, colorants, heat stabilizers, plasticizers, etc.), as well as other polymer compounds and inorganic substances may be added.

Particularly in the case of an adhesive composition, in addition to the polyvinyl alcohol resin (A) and the starch compound (B) which are the main components, an aqueous emulsion (C) may be added as a third component, Further, a crosslinking agent (D) may be added as the fourth component.

The aqueous emulsion (C) used in the adhesive composition of the present invention includes styrene-butadiene copolymer latex, acrylonitrile-butadiene copolymer latex, chloroprene latex, poly (meth) latex.
Examples thereof include acrylic ester emulsion, butyl rubber latex, polyvinylidene chloride emulsion, polyvinyl chloride emulsion, polybutadiene latex, methyl methacrylate-butadiene copolymer latex, ethylene-vinyl acetate copolymer emulsion, polyvinyl acetate emulsion and the like. These latexes or emulsions are carboxyl group-modified,
It may be a modified product containing a primary alcohol group. The mixing ratio of the polyvinyl alcohol resin (A) and the aqueous emulsion (C) is not particularly limited, but the aqueous emulsion (C) is 10 to 600 in terms of solid content based on 100 parts by weight of the polyvinyl alcohol resin (A). Parts by weight are preferred,
50 to 300 parts by weight is more preferable.

The cross-linking agent (D) used in the adhesive composition of the present invention includes the hydroxyl group of the polyvinyl alcohol resin (A) used in the present invention, the starch compound (B) and the aqueous emulsion (C). Reacts with the contained carboxyl groups and other functional groups to form a crosslinked structure,
It refers to one that forms a water-insoluble adhesive layer. For example 2
Examples of the polyvalent isocyanate compound having a valence of 3 or more include tolylene diisocyanate (TDI),
Hydrogenated TDI, trimethylolpropane-TDI adduct, triphenylmethane triisocyanate (TT
I), methylene bis-diphenyl isocyanate (MD
I), hydrogenated MDI, hexamethylene diisocyanate, xylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate and the like. Since these isocyanate compounds react with water, they are hardly soluble in water and are preferably dissolved in a solvent which dissolves the isocyanate compound before use. Furthermore, by adding a surfactant to the isocyanate compound-solvent system, the usable time becomes longer and the crosslinking efficiency is improved. Other cross-linking agents that can be used include polyhydric aldehyde compounds such as glyoxal and glutaraldehyde, polyhydric epoxy compounds, and boron compounds such as boric acid and borate. The mixing ratio of the cross-linking agent (D) is not particularly limited, but is preferably 0.5 to 100 parts by weight in terms of solid content with respect to 100 parts by weight of the polyvinyl alcohol resin (A).
˜50 parts by weight is more preferred.

If necessary, a filler, an antiseptic, a fungicide, an antifoaming agent, a thickener, a wettability improver, a fragrance, a coloring agent and the like may be added. Further, starches, gums, CMC, MC and sodium alginate can be added for the purpose of improving the fluidity and adhesiveness of the paste solution. As a filler,
In addition to inorganic fillers such as clay, talc and calcium carbonate, organic fillers such as wood powder, walnut shell powder, urea resin and melamine resin can also be used. To produce an aqueous adhesive using the adhesive composition of the present invention, the polyvinyl alcohol resin (A), the starch compound (B), the filler and the like are put into water with stirring and the temperature is raised. And dissolve. When the aqueous emulsion (C) is further blended, the above adhesive solution is cooled and then the aqueous emulsion (C) is mixed with stirring. Also a cross-linking agent (D)
Although it depends on the composition, it is usually added just before using the adhesive.

When the adhesive composition of the present invention is dissolved in water, depending on the type of the starch compound (B), the amount is 100.
It may not dissolve in water below ℃, in which case it will dissolve at high temperature in a pressure vessel such as an autoclave. The adhesive composition of the present invention is particularly suitable for paper and wood.
Specific examples thereof include plywood or secondary processing for woodworking, wood for particleboard, etc., corrugated paper / wooden, cloth, fiber processing, ceramics, inorganic plates, mineral inorganic plates. Adhesives for plastic sheets, glass, etc. When the adhesive composition of the present invention is used for adhesion, sufficient adhesion can be obtained even at room temperature, but it is necessary to improve the adhesion, especially the water resistant adhesion, or depending on the type of adherend. May be thermocompression bonded.

The paper to which the barrier agent for paper and the surface sizing agent for paper of the present invention is applied is not particularly limited,
For example, manila balls, white balls, paperboards such as liners, general high-quality papers, medium-quality papers, printing papers such as gravure papers, release papers,
A suitable example is information processing paper. In the case of a surface sizing agent for paper, a base paper for newsprint is particularly preferable.

The coating amount of the barrier agent for paper of the present invention is not particularly limited, but is usually 0.01 to 30 g / m ↑ 2, preferably 0.05 to 20 g / m ↑ 2, and even more preferably 0.02.
It is 1 to 10 g / m ↑ 2. The coating amount of the surface sizing agent for paper of the present invention is preferably 0.01 to 10 g / m ↑ 2, more preferably 0.03 to 5 g / m ↑ 2, and more preferably 0.03 g / m ↑ 2.
More preferably, it is 05 to 1 g / m ↑ 2.

The surface sizing agent for paper of the present invention can be applied to any coating method, but using a roll coater at a speed of 300 m / min or more (1000 m / min or more, further 1500 m / min or more). Even in the case of coating, a coated paper exhibiting good coatability and good surface strength can be obtained.

[0037]

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In the following, "parts" and "%" mean "parts by weight" and "% by weight" respectively, unless otherwise specified.

The following Examples 1-11 and Comparative Examples 1-2
Next, the composition of the present invention will be specifically described. In these Examples and Comparative Examples, simply the degree of polymerization of polyvinyl alcohol means the viscosity average degree of polymerization determined by the usual method from the viscosity of the aqueous solution of polyvinyl alcohol as shown in the text. Aqueous solution compatibility is PVA
An aqueous solution containing (A) and the starch compound (B) at a concentration of 10% was prepared, and the obtained aqueous solution was allowed to stand still at 70 ° C., and the phase separation state was visually observed to make a determination. The tensile strength and elongation of the film was prepared by preparing an aqueous solution containing PVA (A) and a starch compound (B) at a concentration of 10%,
The film having a thickness of about 50μ was cast on a rotating drum covered with a polyester film having a surface temperature of 70 ° C and dried, and the humidity between the films was adjusted at 20 ° C and 65% RH for 10 days. It was measured by a method of pulling at 50 mm at a pulling rate of 500 mm / min in a direction perpendicular to the film forming direction.

Example 1 Polyvinyl alcohol (A) having a degree of polymerization of 1720 and a saponification degree of 88.1 mol% was graft-polymerized with 15 parts of acrylic acid to 100 parts of oxidized starch (B) (10% aqueous solution). 90 ° C. viscosity: 30 cP) was blended in a weight ratio of 100: 100 to dissolve the composition in water to prepare an aqueous solution, which was allowed to stand at 70 ° C. to visually observe the phase separation state. It was confirmed that the solubility was good. Further, the surface temperature of the obtained aqueous solution is 70 ° C.
A film having a thickness of 50 μm obtained by casting on a rotary drum covered with the above polyester film and drying it was subjected to a tensile test, and it was confirmed that the film had good tensile strength and elongation. Table 1 shows the compatibility between the aqueous solutions and the tensile strength and elongation of the obtained film.

Example 2 The PVA (A) used in Example 1 was polymerized with a polymerization degree of 1720,
Polyvinyl alcohol (A) having a saponification degree of 98.5 mol%
Evaluation was made in the same manner as in Example 1 except that The compatibility of the aqueous solution and the tensile strength and elongation of the obtained film were good. The results are shown in Table 1.

Example 3 Evaluation was made in the same manner as in Example 1 except that the PVA (A) used in Example 1 was changed to polyvinyl alcohol (A) having a polymerization degree of 580 and a saponification degree of 88.0 mol%. . The compatibility of the aqueous solution and the tensile strength and elongation of the obtained film were good. The results are shown in Table 1.

Example 4 PVA (A) used in Example 1 was mixed with 1 mol% of itaconic acid.
Example 1 except that the polyvinyl alcohol (A) having a polymerization degree of 1700 and a saponification degree of 97 mol% was copolymerized.
Evaluated in the same way as. The compatibility of the aqueous solution and the tensile strength and elongation of the obtained film were good. The results are shown in Table 1.

Example 5 The grafted starch (B) used in Example 2 was prepared by graft-polymerizing 15 parts of methacrylic acid with 100 parts of oxidized starch by graft polymerization (B) (viscosity of a 10% aqueous solution at 90 ° C .: 18 cP), except that the evaluation was performed in the same manner as in Example 2. The compatibility of the aqueous solution and the tensile strength and elongation of the obtained film were good. The results are shown in Table 2.

Example 6 The grafted starch (B) used in Example 2 was prepared by graft polymerizing 5 parts of acrylic acid with 100 parts of oxidized starch by graft polymerization (B) (90% of 10% aqueous solution).
C. Viscosity: 4 cP) was changed and evaluated in the same manner as in Example 2. The compatibility of the aqueous solution and the tensile strength and elongation of the obtained film were good. The results are shown in Table 2.

Comparative Example 1 Grafted starch (B) used in Example 1 was used as commercially available oxidized starch (manufactured by Japan Food Processing Co., Ltd., MS-380).
Evaluation was made in the same manner as in Example 1 except that the value was changed to 0). Both the compatibility of the aqueous solution and the tensile strength and elongation of the obtained film were significantly decreased. The results are shown in Table 2.

Comparative Example 2 Evaluation was made in the same manner as in Example 1 except that the grafted starch (B) used in Example 1 was changed to commercially available corn starch. Both the compatibility of the aqueous solution and the tensile strength and elongation of the obtained film were significantly decreased. The results are shown in Table 2.

Examples 7 to 11 The grafted starch (B) used in Example 1 is shown in Table 3.
Evaluation was made in the same manner as in Example 1 except that the grafted starch (B) shown in was changed. The compatibility of the aqueous solution and the tensile strength of the obtained film were good. The results are shown in Table 3.
Shown in.

[0048]

[Table 1]

[0049]

[Table 2]

[0050]

[Table 3]

The following Examples 12 to 20 and Comparative Examples 3 to
In Section 7, the film of the present invention will be described more specifically. In these Examples and Comparative Examples, the tensile strength and elongation of the films were covered with a polyvinyl ester film prepared by blending an aqueous solution of a polyvinyl alcohol resin (A) and a starch compound (B) with a surface temperature of 70 ° C. A film with a thickness of about 50μ obtained by casting on a rotary drum and drying is used at 20 ° C. and 65% RH for 1 hour.
The humidity was measured for 0 days, the distance between chucks was 50 mm, and the measurement was performed by a method of pulling in a direction perpendicular to the film forming direction at a pulling speed of 500 mm / min.

Example 12 A starch compound (B) obtained by graft-polymerizing 15 parts by weight of acrylic acid with 100 parts by weight of polyvinyl alcohol (A) having a polymerization degree of 1720 and a saponification degree of 88.1 mol% and 100 parts by weight of oxidized starch (B). ) Is blended in a weight ratio of 100: 100, and the resulting aqueous solution is dissolved in water to obtain an aqueous solution, which is cast on a rotating drum covered with a polyester film having a surface temperature of 70 ° C., and dried. A tensile test was performed on the obtained film having a thickness of 50 μm, and it was confirmed that the film had good tensile strength and elongation. Table 4 shows the results of the tensile test of the film and the morphological changes after the film was buried in the ground 30 cm for 6 months.

Example 13 Evaluations were made in the same manner as in Example 12 except that the compounding ratio of PVA (A) and starch compound (B) used in Example 12 was changed to a weight ratio of 100: 50. When the film was subjected to a tensile test, the tensile strength and elongation of the film were good. Table 4 shows the results of the tensile test of the film and the morphological changes after the film was buried in the ground 30 cm for 6 months.

Example 14 PVA (A) used in Example 12 was polymerized with a polymerization degree of 1720,
Polyvinyl alcohol (A) having a saponification degree of 98.5 mol%
Evaluation was made in the same manner as in Example 12 except that When the film was subjected to a tensile test, the tensile strength and elongation of the film were good. The tensile test result of the film,
Table 4 shows the morphological changes after the film was buried in the ground 30 cm for 6 months.

Example 15 Obtained by graft-polymerizing 5 parts by weight of acrylic acid with 100 parts by weight of polyvinyl alcohol (A) copolymerized with a polymerization degree of 1700, a saponification degree of 97 mol% and itaconic acid of 3 mol%, and 100 parts by weight of oxidized starch. An aqueous solution obtained by blending the obtained starch compound (B) in a weight ratio of 100: 100 is cast on a rotary drum covered with a polyester film having a surface temperature of 70 ° C., and dried. A tensile test was performed on the obtained film having a thickness of 50 μm, and it was confirmed that the film had good tensile strength and elongation. Table 4 shows the results of the tensile test of the film and the morphological changes after the film was buried in the ground 30 cm for 6 months.

[0056]

[Table 4]

Comparative Example 3 Instead of the starch compound (B) used in Example 12, commercially available oxidized starch (manufactured by Japan Food Processing Co., Ltd., MS) was used.
-3800) was used and evaluated in the same manner as in Example 12. When the film was subjected to a tensile test, the tensile strength and elongation of the film were significantly reduced. Table 5 shows the results of the tensile test of the film and the morphological changes after the film was buried in the ground 30 cm for 6 months.

Comparative Example 4 Example 12 except that a commercially available corn starch was used in place of the starch compound (B) used in Example 12.
Evaluated in the same way as. When the film was subjected to a tensile test, the tensile strength and elongation of the film were significantly reduced. Film tensile test results and film 30
Table 5 shows the morphological changes after burial in cm for 6 months.

Comparative Example 5 A film prepared by casting in the same manner as in Example 12 using only the starch compound (B) used in Example 12 had a very low tensile strength and elongation. The tensile test results of the film and the obtained film 6
Table 5 shows the morphological changes after being buried for a month.

Comparative Example 6 A film made by casting in the same manner as in Example 12 using only PVA (A) used in Example 12 had a good tensile strength and elongation. Table 5 shows the results of the tensile test of the film and the morphological changes after the film was buried in the ground 30 cm for 6 months.

Comparative Example 7 Melt extrusion film formation was carried out at 160 ° C. using only commercially available low density polyethylene to obtain a film having a thickness of 50 μm. Table 5 shows the tensile strength / elongation of the film and the morphological change after the film was buried in 30 cm underground for 6 months.

[0062]

[Table 5]

Examples 16 to 20 The starch compound (B) used in Example 12 is shown in Table 6.
Evaluation was carried out in the same manner as in Example 12 except that the starch compound (B) shown in was changed. When the film was subjected to a tensile test, the tensile strength and elongation of the film were good.
Table 6 shows the results of the tensile test of the film and the morphological changes after the film was buried in the ground 30 cm for 6 months.

[0064]

[Table 6]

The following Examples 21 to 28 and Comparative Examples 8 to
In Section 9, the adhesive composition of the present invention will be described more specifically. Example 21 Grafted starch (B) obtained by graft-polymerizing 15 parts by weight of acrylic acid with 100 parts by weight of PVA (A) having a polymerization degree of 1720 and a saponification degree of 96 mol% and 100 parts by weight of oxidized starch.
An adhesion test was conducted using an adhesive composition containing (10% aqueous solution at 90 ° C. viscosity: 30 cp) as a main component. P above
40 parts of VA (A), 12 of the above grafted starch (B)
Parts, 58 parts of kaolin clay, 1.2 parts of carboxymethyl cellulose and 0.1 parts of an antifoaming agent were added to 400 parts of water while stirring and dissolved by heating to obtain an adhesive. This adhesive had a solid content of 21.6%, a pH of 4.3, and a B-type viscosity of 2060 cp at 30 ° C. Base paper for paper tubes (basis weight 412g
/ M2, bump size 34 seconds, size 20 x 100m
After the adhesive of the present invention is applied to m) at 50 g / m 2 (wet), another base paper which has not been applied immediately is overlaid to 200 g.
After pressing with a pressure of / cm @ 2 for 30 seconds, the peel adhesion strength was measured at each adhesion time. Next, the adhesive was charged into an applicator roll, and the roll speed was 80 m / min and 12
Coating is performed at 0 m / min, the adhesiveness between the rolls, the roll transferability of whether or not the paste liquid is uniformly applied to the transfer roll,
When the thread drawability of the sizing liquid between the rolls was tested, there was no glue fly at roll speeds of 80 m / min and 120 m / min, and roll transferability and thread drawability were also good. The results are shown in Table 7.

Comparative Example 8 Initial adhesive strength and roll coating were carried out in the same manner as in Example 21 except that the grafted starch (B) was not used and the amount of carboxymethyl cellulose used was 1.8 parts. And stringiness were tested. This adhesive is
The solid content was 20.0%, the pH was 6.2, and the B-type viscosity at 30 ° C was 1930 cp. The initial adhesive strength of this adhesive was insufficient, and roll coatability was particularly poor at a coating speed of 120 m / min, which resulted in severe glue skipping and stringing. The results are shown in Table 7.

[0067]

[Table 7]

Example 22 An adhesive for woodworking was prepared using the PVA (A) and the grafted starch (B) used in Example 21. PV above
28 parts of A (A) and 12 parts of grafted starch (B) are dissolved in an autoclave equipped with a stirrer at 120 ° C. for 1 hour, and 2
A 2.9% aqueous solution was prepared. 175 parts of the obtained aqueous solution was added to a styrene-butadiene copolymer latex (C).
(Japan Synthetic Rubber Co., Ltd., JSR0692) 120 parts,
80 parts of kaolin clay was added, and methylene bis-diphenyl isocyanate (MD) was used as a crosslinking agent (D).
I) 8 parts was added and well stirred to obtain the adhesive of the present invention. Using this adhesive, a 3 mm plywood of 0.8 / 1.4 / 0.8 mm veneer structure is applied with a coating amount of 30 g / m 2, cold pressure (cold pressure 10 kg / cm 2, 10 minutes), thermocompression bonding (heat pressure 120
C., 10 kg / cm2, 1 minute)
Adhesive force was measured according to the method. The results are shown in Table 8. It was applied at a speed of 85 m / min using a spreader roll, but there was almost no glue splattering and there was no streak of the adhesive on the roll, which was good.

Comparative Example 9 Instead of the grafted starch (B) used in Example 22, commercially available oxidized starch (10% aqueous solution at 90 ° C. viscosity: 6) was used.
0 cp) was used and an adhesive was prepared in the same manner as in Example 22, and the adhesive strength was measured. The results are shown in Table 8.
The roll coatability was very severe with glue skipping, and glue streaks occurred on the roll, resulting in uneven coating.

[0070]

[Table 8]

Examples 23 to 28 By changing the PVA (A) and the grafted starch (B) used, adhesives for interleaving paper were prepared, and in the same manner as in Example 21,
Adhesion performance and roll coatability were tested. The results are shown in Tables 9 and 10. In addition, in Examples 24 and 27, vinylacetamide and vinyl acetate were used as monomers for grafting, respectively, and after graft polymerization, alcoholysis was carried out in a methanol solvent using sodium hydroxide as a catalyst to obtain polyvinylamine and polyvinylamine, respectively. An adhesive of the present invention was prepared using a grafted starch (B) made of a graft polymer having an alcohol group and tested.

[0072]

[Table 9]

[0073]

[Table 10]

The following Examples 29-41 and Comparative Example 10
-14, the barrier agent for paper of the present invention will be described more specifically. In these examples and comparative examples,
The term "polymerization degree of polyvinyl alcohol" simply means the viscosity average degree of polymerization obtained by a usual method from the viscosity of the aqueous solution of polyvinyl alcohol as shown in the text. The gate roll coater has a diameter of 200m as an outer roll.
m rubber roll, inner diameter 200 mm
Diameter of 360 as metal roll and applicator roll
mm rubber roll, diameter 34 as backup roll
A test machine consisting of 9 mm rubber rolls was used, and the peripheral speed of each roll was unified to 300 m / min. When the gate roll coater is applied, the liquid film on the roll becomes streaky, and the degree of coating unevenness due to the fact that it is transferred onto the paper is evaluated by the generation of streaks in the liquid film on the inner roll. The degree of scattering of the coating liquid was evaluated by visually observing the mist generated between the inner roll and the applicator. The barrier property is 73 g / m ↑ 2 with a gate roll coater and an air permeability of 1
Coated on high quality paper for 5 seconds and immediately dried at 100 ° C for 1 minute using a rotary dryer.
After conditioning the humidity in a room at a constant temperature and humidity of% RH for 1 week,
The measurement was carried out in a constant temperature and humidity room of 65% RH by the method described in JIS P-8130. The viscosity of the coating liquid was measured at 25 ° C and a rotation speed of 60 rpm using a B-type viscometer manufactured by Tokyo Keiki.

Example 29 A starch-based compound (B) obtained by graft-polymerizing 15 parts of acrylic acid with 100 parts of polyvinyl alcohol (A) having a polymerization degree of 580 and a saponification degree of 88.1 mol% and 100 parts of oxidized starch.
A composition prepared by blending (10% aqueous solution at 90 ° C. viscosity: 30 cP) in a weight ratio of 100: 25 is dissolved in water to obtain a coating solution (water is used as a solvent also in the following Examples and Comparative Examples. Was prepared and the viscosity of the obtained coating liquid was adjusted to 25
It was set to 200 cP at ° C. No scattering of the coating liquid was observed during the gate roll coater coating of this coating liquid. Using a gate roll coater, basis weight 73g / m ↑
2. Air quality of 15 seconds, coated with solid content of about 3g /
The coating liquid was applied so that m ↑ 2, and the coated paper immediately dried with a rotary dryer at 100 ° C for 1 minute was conditioned at 20 ° C and 65% RH in a constant temperature and constant humidity chamber for 1 week. Then, JIS P in a constant temperature and humidity room at 20 ° C and 65% RH.
When the barrier property was measured by the method shown in -8130, a value of 100,000 seconds or more was confirmed, and it was confirmed that the barrier property was good. Table 11 shows the composition and coating amount of the barrier agent (coating liquid), the barrier property, and the coating property.

Example 30 The blending ratio of the polyvinyl alcohol (A) and the starch compound (B) used in Example 29 was 100: 5 by weight.
The coating property and barrier property were evaluated in the same manner as in Example 29 except that the content was changed to 0. Table 11 shows the composition and coating amount of the barrier agent, barrier properties, and coatability.

Example 31 The polyvinyl alcohol (A) used in Example 29 and the starch compound (B) were mixed in a weight ratio of 100: 1.
The coating property and barrier property were evaluated in the same manner as in Example 29 except that the value was changed to 00. Table 11 shows the composition and coating amount of the barrier agent, barrier properties, and coatability.

Example 32 The polyvinyl alcohol (A) used in Example 29 and the starch compound (B) were mixed in a weight ratio of 100: 2.
The coating property and barrier property were evaluated in the same manner as in Example 29 except that the value was changed to 00. Table 11 shows the composition and coating amount of the barrier agent, the barrier property, and the coatability.

Example 33 The starch compound (B) used in Example 29 was replaced with the starch compound (B) obtained by graft-polymerizing 15 parts of methacrylic acid with 100 parts of oxidized starch (90% of a 10% aqueous solution). The coating property and the barrier property were evaluated in the same manner as in Example 29 except that the viscosity: 18 cP) was used. Table 11 shows the composition and coating amount of the barrier agent, barrier properties, and coatability.

Example 34 Instead of the starch compound (B) used in Example 29, 5 parts of acrylic acid was graft-polymerized with 100 parts of oxidized starch (B) (90% of a 10% aqueous solution). Coating properties and barrier properties were evaluated in the same manner as in Example 29 except that PVA (A) and the starch compound (B) were blended at a weight ratio of 100: 20 using a viscosity of 4 cP). . Composition and application amount of barrier agent,
Table 11 shows the barrier properties and coatability.

[0081]

[Table 11]

Example 35 Coating in which polyvinyl alcohol (A) having a polymerization degree of 700 and a saponification degree of 95.0 mol% and the starch compound (B) used in Example 29 were blended at a weight ratio of 100: 25. A liquid was prepared and the coating properties and barrier properties were evaluated in the same manner as in Example 29. Composition and application amount of barrier agent,
Table 12 shows the barrier properties and coatability.

Example 36 Polyvinyl alcohol (A) copolymerized with 1 mol% of itaconic acid and having a polymerization degree of 1000 and a saponification degree of 97 mol% and the starch compound (B) used in Example 29 were mixed in a weight ratio of 10.
A coating liquid blended at a ratio of 0:25 was prepared, and the coating property and the barrier property were evaluated in the same manner as in Example 29. Table 12 shows the composition and coating amount of the barrier agent, barrier properties, and coatability.

Comparative Example 10 A coating solution containing only polyvinyl alcohol (A) having a polymerization degree of 580 and a saponification degree of 88.1 mol% was prepared, and the coating property and barrier property were evaluated in the same manner as in Example 29. Although the coated paper had good barrier properties, streaking was remarkable when the coating liquid was applied to the gate roll coater, and further scattering of the coating liquid was observed. Table 12 shows the composition and coating amount of the barrier agent, barrier properties, and coatability.

Comparative Example 11 A coating solution containing only polyvinyl alcohol (A) having a degree of polymerization of 1000 and a degree of saponification of 97 mol% obtained by copolymerizing 1 mol% of itaconic acid was prepared in the same manner as in Example 29. When the barrier property of the coated paper was evaluated, the barrier property of the coated paper was deteriorated, and when the coating liquid was applied to the gate roll coater, streaks were remarkably generated and scattering of the coating liquid was recognized. Moreover, when the presence state of PVA in the coated paper was confirmed by an iodine dyeing method, remarkable coating unevenness was confirmed. Table 12 shows the composition and coating amount of the barrier agent, barrier properties, and coatability.

Comparative Example 12 A coating solution containing only the starch compound (B) used in Example 29 was prepared and the coating properties and barrier properties were evaluated in the same manner as in Example 29. The barrier property was deteriorated, streaks were remarkably generated when the coating liquid was applied to the gate roll coater, and scattering of the coating liquid was observed. Moreover, when the presence state of PVA in the coated paper was confirmed by an iodine dyeing method, remarkable coating unevenness was confirmed. Table 12 shows the composition and coating amount of the barrier agent, barrier properties, and coatability.

[0087]

[Table 12]

Comparative Example 13 Instead of the starch compound (B) used in Example 29, commercially available oxidized starch (manufactured by Japan Food Processing Co., Ltd., MS) was used.
-3800) was used and the coating properties and barrier properties were evaluated in the same manner as in Example 29. As a result, the barrier properties of the coated paper were reduced, and when the coating liquid was applied to a gate roll coater, the stripes of Occurrence was remarkable, and scattering of the coating liquid was recognized. Moreover, when the presence state of PVA in the coated paper was confirmed by an iodine dyeing method, remarkable coating unevenness was confirmed.
Table 13 shows the composition and coating amount of the barrier agent, the barrier property, and the coating property.

COMPARATIVE EXAMPLE 14 A commercially available coating solution containing only oxidized starch used in Comparative Example 13 was prepared and the coating properties and barrier properties were evaluated in the same manner as in Example 29. The coating properties were good. However, the barrier property of the coated paper was not good. Table 13 shows the composition and coating amount of the barrier agent, the barrier property, and the coating property.

[0090]

[Table 13]

Examples 37 to 41 Table 13 shows the starch compounds (B) used in Example 29.
A coating solution was prepared in the same manner as in Example 29 except that the starch-based compound (B) shown in (4) was used, and the coating properties and barrier properties were evaluated in the same manner as in Example 29. Table 14 shows the composition and coating amount of the barrier agent, barrier properties, and coatability.

[0092]

[Table 14]

The following Examples 42 to 64 and Comparative Example 15
-18, the surface sizing agent for paper of the present invention will be described more specifically. In these Examples and Comparative Examples, simply the degree of polymerization of polyvinyl alcohol means the viscosity average degree of polymerization determined by the usual method from the viscosity of the aqueous solution of polyvinyl alcohol, as shown in the text. The gate roll coater is a test machine including a rubber roll having a diameter of 200 mm as an outer roll, a metal roll having a diameter of 200 mm as an inner roll, a rubber roll having a diameter of 360 mm as an applicator roll, and a rubber roll having a diameter of 349 mm as a backup roll, and the peripheral speed of each roll is Unified to 300 m / min. Using this gate roll coater, a coating solution was applied to a base paper for newsprint of 43 g / m ↑ 2 and immediately dried at 100 ° C for 1 minute using a rotary dryer, and then 20 ° C.
After conditioning in a room with constant temperature and humidity of 65% RH for 1 week, 2
Picking oil M, printing pressure 35 kg / c by IGT printability tester in a constant temperature and humidity room at 0 ° C and 65% RH.
m, spring drive M, IGT pick was measured. It should be noted that the larger the IGT pick value, the higher the surface strength. The IGT pick 70 cm / s was used for the newsprint base paper used in the test without any coating.
It was ec. The scattering of the coating liquid during the gate roll coater coating was evaluated by visually observing the mist generated between the inner roll and the applicator roll. The viscosity of the coating liquid was measured at 25 ° C. and a rotation speed of 60 rpm using a B-type viscometer manufactured by Tokyo Keiki.

Example 42 Polyvinyl alcohol (A) having a degree of polymerization of 1720 and a degree of saponification of 99.5 mol%, and grafted starch (B) (10%) obtained by graft-polymerizing 15 parts by weight of acrylic acid to 100 parts by weight of oxidized starch. 90 ° C viscosity of aqueous solution: 30 cP)
Was dissolved in water to prepare a coating solution (water was used as a solvent also in the following Examples and Comparative Examples) to prepare a coating solution. The viscosity of the solution was 50 cP at 25 ° C. No scattering of the coating liquid was observed during the gate roll coater coating of this coating liquid. Table 15 shows the surface strength of the obtained coated paper.

Example 43 Polyvinyl alcohol (A) having a degree of polymerization of 1720 and a degree of saponification of 99.5 mol% and the grafted starch (B) used in Example 42 were blended at a weight ratio of 100: 10. Create a working fluid and set the viscosity of the resulting coating fluid to 2
It was 50 cP at 5 ° C. No scattering of the coating liquid was observed during the gate roll coater coating of this coating liquid. Table 15 shows the surface strength of the obtained coated paper.

Comparative Example 15 A coating solution containing only polyvinyl alcohol (A) having a polymerization degree of 1720 and a saponification degree of 99.5 mol% was prepared, and the viscosity of the obtained coating solution was set to 50 cP at 25 ° C. Remarkable scattering of the coating liquid was observed during the gate roll coater coating of this coating liquid. Table 16 shows the surface strength of the obtained coated paper.

Example 44 Polyvinyl alcohol (A) having a degree of polymerization of 1490 and a degree of saponification of 99.5 mol% and the grafted starch (B) used in Example 42 were blended at a weight ratio of 100: 5. Create a working fluid and adjust the viscosity of the resulting coating fluid to 25
It was set to 50 cP at ° C. No scattering of the coating liquid was observed during the gate roll coater coating of this coating liquid. Table 15 shows the surface strength of the obtained coated paper.

Example 45 Polyvinyl alcohol (A) having a degree of polymerization of 1720 and a degree of saponification of 99.5 mol% and grafted starch (B) (10% aqueous solution) obtained by graft-polymerizing 15 parts of methacrylic acid to 100 parts by weight of oxidized starch. 90 ° C. viscosity: 18 cP) was blended at a weight ratio of 100: 20 to prepare a coating liquid, and the viscosity of the obtained coating liquid was 50 cP at 25 ° C.
And No scattering of the coating liquid was observed during the gate roll coater coating of this coating liquid. Table 15 shows the surface strength of the obtained coated paper.

Example 46 Polyvinyl alcohol (A) having a degree of polymerization of 1720 and a degree of saponification of 99.5 mol% and grafted starch (B) obtained by graft-polymerizing 5 parts of acrylic acid to 100 parts by weight of oxidized starch (10% aqueous solution). 90 ° C. viscosity: 4 cP) was blended at a weight ratio of 100: 20 to prepare a coating liquid, and the viscosity of the obtained coating liquid was set to 50 cP at 25 ° C. No scattering of the coating liquid was observed during the gate roll coater coating of this coating liquid. Table 15 shows the surface strength of the obtained coated paper.

Example 47 Polyvinyl alcohol (A) having a degree of polymerization of 1720 and a degree of saponification of 88.2 mol% and the grafted starch (B) used in Example 42 were blended at a weight ratio of 100: 20. Create a working fluid and set the viscosity of the resulting coating fluid to 2
It was 50 cP at 5 ° C. No scattering of the coating liquid was observed during the gate roll coater coating of this coating liquid. Table 15 shows the surface strength of the obtained coated paper.

Example 48 Polyvinyl alcohol (A) having a degree of polymerization of 580 and a saponification degree of 88.1 mol% and the grafted starch (B) used in Example 42 were blended at a weight ratio of 100: 5. Create a working solution and adjust the viscosity of the resulting coating solution to 25 ° C.
To 50 cP. No scattering of the coating liquid was observed during the gate roll coater coating of this coating liquid. Table 16 shows the surface strength of the obtained coated paper.

Example 49 Polyvinyl alcohol (A) having a polymerization degree of 1700 and a saponification degree of 97 mol% obtained by copolymerizing 1 mol% of itaconic acid and the grafted starch (B) used in Example 42 were mixed in a weight ratio of 1.
A coating solution was prepared by blending in a ratio of 00:20, and the viscosity of the obtained coating solution was set to 50 cP at 25 ° C.
No scattering of the coating liquid was observed during the gate roll coater coating of this coating liquid. Table 16 shows the surface strength of the obtained coated paper.

Comparative Example 16 A coating solution containing only polyvinyl alcohol (A) having a polymerization degree of 580 and a saponification degree of 88.1 mol% was prepared, and the viscosity of the obtained coating solution was 50 cP at 25 ° C. When the gate roll coater was coated with this coating liquid, a significant scattering of the coating liquid was recognized, although it was less than in Comparative Example 15. Table 16 shows the surface strength of the obtained coated paper.

Comparative Example 17 A coating solution containing only polyvinyl alcohol (A) having a polymerization degree of 1700 and a saponification degree of 97 mole% was prepared by copolymerizing 1 mol% of itaconic acid, and the viscosity of the obtained coating liquid was 25 ° C. At 50c
It was set to P. When the coating liquid was applied to a gate roll coater, remarkable scattering of the coating liquid was observed. Table 16 shows the surface strength of the obtained coated paper.

Comparative Example 18 A coating solution containing only the grafted starch (B) used in Example 42 was prepared, and the viscosity of the resulting coating solution was 50 at 25 ° C.
It was set to cP. No scattering of the coating liquid was observed during the gate roll coater coating of this coating liquid, but the surface strength of the coated paper was greatly reduced. Table 16 shows the surface strength of the obtained coated paper.

Examples 50 to 54 The grafted starch (B) used in Example 42 is shown in Table 1.
Example 4 except that the grafted starch shown in 7 was changed.
A coating solution was prepared in the same manner as in 2. No scattering of the coating liquid was observed during the gate roll coater coating of this coating liquid. Table 17 shows the surface strength of the obtained coated paper.

[0107]

[Table 15]

[0108]

[Table 16]

[0109]

[Table 17]

[0110]

INDUSTRIAL APPLICABILITY The composition of the present invention has an excellent compatibility, and an aqueous solution which does not undergo phase separation even when left for a long time is obtained, and the strength and elongation of the obtained film are good. It is extremely expensive. The film of the present invention is tough and has a property of being rapidly biodegradable when left outdoors, and therefore has an extremely high industrial value as an agricultural material such as an agricultural mulch film, a disposable shopping bag, or the like. . The adhesive composition of the present invention is excellent in high-speed coating property, has no troubles such as coating unevenness and scattering of paste solution, and has excellent initial adhesive strength. Therefore, the adhesive composition of the present invention is useful as an adhesive for all kinds of materials, and is particularly useful as an adhesive for paper and an adhesive for wood. The barrier agent for paper of the present invention has excellent barrier properties and is superior in high-speed coating property to conventional barrier agents. That is, the paper barrier agent of the present invention is extremely industrially valuable because troubles such as coating unevenness during coating and scattering of the coating liquid from the roll do not easily occur even when coating at high speed. is there. The surface sizing agent for paper of the present invention is superior in coating properties than conventional surface sizing agents, and troubles such as splattering of the coating liquid hardly occur even when coating at high speed, and the obtained coated paper It has an extremely high industrial value in terms of its high surface strength and good printability. Furthermore, the coated paper manufacturing method of the present invention has good coatability even when it is coated at a high speed using a roll coater, and the obtained paper has a large surface strength and good printability.

Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location C08L 51/02 LKV 7142-4J C09J 129/04 JCU 6904-4J D21H 19/12 (31) Special priority claim number Special Japanese Patent Application No. 4-143179 (32) Priority Date 4 (1992) May 7 (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. 4-148325 (32) Priority Date 4 (1992) May 13 (33) Priority claiming country Japan (JP) (72) Inventor Hirotoshi Miyazaki 1621 Sakata, Kurashiki City, Okayama Prefecture Kuraray Co., Ltd. (72) Inventor Sadahiko Shirakami Satsuki, Kurashiki City, Okayama Prefecture 1621 Kuraray Co., Ltd. (72) Inventor Hitoshi Maruyama 1621 Sakata, Kurashiki-shi, Okayama Prefecture Kuraray Co., Ltd. (72) Inventor Norio Hoshishiki 1-31 Yamada Nishi, Suita City, Osaka D-504 (72) Inventor Toru Nakajima 1-49, Higashiminato-cho, Sakai City, Osaka Prefecture (72) Inventor, Mihiro Watanabe 21-Kakiuchi, Izumi, Osaka

Claims (6)

[Claims] 1. A carboxyl group-containing monomer, a sulfonic acid group-containing monomer, an amino group-containing monomer, and a quaternary ammonium base-containing monomer based on 100 parts by weight of the polyvinyl alcohol resin (A) and the starch structure portion. A 10% by weight aqueous solution obtained by graft-polymerizing 1 to 200 parts by weight of at least one monomer selected from monomers, amide group-containing monomers, vinyl esters and vinylpyrrolidone has a viscosity of 1000 cP or less. A composition comprising a starch compound (B). 2. A film comprising the composition of claim 1. 3. An adhesive composition comprising the composition according to claim 1. 4. A barrier agent for paper comprising the composition according to claim 1. 5. A surface sizing agent for paper, which comprises the composition according to claim 1. 6. A method for producing coated paper, which comprises applying the surface sizing agent for paper according to claim 5 using a roll coater at a speed of 300 m / min or more.