JPS5823867A - Remoistening hot-melt adhesive composition - Google Patents

Abstract

PURPOSE:The titled composition prepared by incorporating a specific PVA with a polyhydric alcoholic ester of boric acid and if necessary a plasticizer, having improved tackiness, adhesive force, blocking property, etc., and suitable for paper. CONSTITUTION:A composition prepared by incorporating 100pts.wt. PVA having a polymerization degree of 50-500, preferably 80-400, and a saponification degree of 40-80mol%, preferably 40-70mol%, maleic acid, with 0.5-50pts.wt. polyhydric alcoholic ester of boric acid, e.g. glycerol ester, and 0-200pts.wt. plasticizer, e.g. polyethylene glycol.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to adhesive compositions having rewetting properties, and more particularly to adhesive compositions having water dispersibility and being suitable for use mainly in paper 7111m. This is related to the possibility of getting a refund.

Traditionally, envelopes, tape, stamps, wopel, and stamps.

Wallpaper and fusuma paper contain latent starch and S-poppy 11
A rewetting adhesive made of γμ force 1 salt is used for m'Elua ρ Co# (hereinafter abbreviated as ``YumebiepAco**Pmum'') or Aku9. However, these rewetting adhesives do not melt under heat, so
Since it needs to be applied as an aqueous dispersion or an organic solvent solution, it requires a drying process before use, resulting in poor productivity and problems such as sticking to each other or curling during the single rolling process. Partially saponified PTA (U.S. Pat. No. 5,597,246) obtained by acid saponifying vinyl mono9 acetate as an adhesive, completely saponified Partially saponified P-mum obtained by re-acetifying P-mum (U.S. Pat. No. 5,444,125), etc. Partially saponified P-mum obtained by a special manufacturing method, hydrophilic groups (carboxylic acid, sulphate, etc.) P-type adhesives modified with monomers containing phosphoric acid, etc.) have been proposed, but the manufacturing process for these adhesives is complicated and the resulting resin has poor thermal stability. There are gaps in sex, wetness, and pro-life sex. ! The reality is that it has not been put to practical use.

In addition, in the 41st Society Bulletin No. 49-9611, the degree of polymerization is 200.
-soo, degree of oxidation 70-80 q/&/excellent f) P T
A composition comprising the plasticizer pentanidythritol has been proposed, but this composition has drawbacks such as high hot melt viscosity and poor thermal stability.

The present inventors have taken advantage of this current situation and have developed a base I9mer that is easy to produce industrially and has fast rewetting properties, excellent tattering properties, low melting viscosity, and good thermal stability.

As a result of intensive research aimed at providing a rewetting hot melt adhesive composition that has good blocking properties and is also easy to work with, we found that boric acid was added to PVA with a specific low degree of polymerization and low saponification. It was discovered that the above object could be achieved by blending the ◆ value of ACO and SDE, if necessary, with a plasticizer, and it was made suitable for zero-start WRC.

That is, the present invention has a hardness of 50 to 500. Saponification degree 40
-100 parts by weight of PVA of ~804N, 1 K of polyhydric alcohol of boric acid, 5-50 parts by weight of SDETV O, and 0 parts by weight of plasticizer.
-200 parts by weight of the adhesive composition.

Table 1 shows the relationship between adhesive composition and physical properties.As shown in Table 1c, PVA with a low degree of polymerization and low saponification alone has poor rewetting properties, and a mixture of only three PVAC plasticizers does not. Although rewetting performance improves! Toughness, adhesive strength is not sufficient, and when polyhydric alcohol ~ ester of acid is added to these, rewetting is possible.

Improves tackiness, adhesion and even blocking properties. It is well known that adding boric acid or its salt to a PVA aqueous solution will increase its viscosity and improve its tackiness, but boric acid and borates do not melt with heat, so they cannot be blended into hot melt adhesives. Therefore, no improvement in tackiness can be expected.

The polyhydric alcohol-rho ester of boric acid used in the present invention is a viscous liquid or solid at room temperature, and when melt-blended with heat-melting PVA, it exhibits the effect of improving tackiness with slight thickening. do.

Table 1 Relationship between adhesive composition and physical properties Urn 1 High quality paper C11I Amount of cloth 20 After discussion with fed, rewet and rewet, then apply a load of 500 t/d and leave for 1 minute, then turn over and tear the paper. I judged it based on the situation.

Jar 2 high-quality paper cm cloth amount 20 After applying with fed, wrap it tightly around a wooden zelkova, then peel it off and judge by the degree of peeling.

The PVA used in the present invention has a polymerization degree of 50-500°, preferably 80-400°. Saponification degree 40-80mol&/g6
゜It is necessary that the degree of polymerization is preferably 40 to 70 to excellent. If the degree of polymerization is less than 50, the adhesive strength will be insufficient, and if it exceeds 500, the melt viscosity will be high, so it is not suitable. Also, if the degree of saponification is 40 If less than mol %, rewetting IC: L L <
*If it exceeds 804ρ%, it is the melting temperature.

The viscosity is high (so it is not suitable).The feature of the present invention is that it improves physical properties such as tackiness and adhesive strength due to the interaction between polyvalent alcohol μ of boric acid and PVA.
The PVA used may be modified with other 7-mers as long as it does not lose its essence as PVA, such as maleic acid, acrylic acid, methacrylic acid, crotonic acid, and salts thereof. PVA modified with vinylpyrrolidone, olefins, etc. can also be used in the present invention.

Examples of the polyalcohol to ester of boric acid used in the present invention include ethyl alcohol, β ester, and
, glycerin ester, tulpitot ρ ester, mannitol ester II, %, #) tLru. Among them, lycerin ester is the most desirable.
It is necessary that iPTA is 0.5 to 50 parts by weight, preferably 5 to 40 parts by weight, based on 100 parts by weight of iPTA. 0
．． If it is less than 5 parts by weight, the effect of improving adhesive strength will be small, and if it exceeds 50 parts by weight, the resin will lose its elasticity, which is not suitable.

As the plasticizer used in the present invention, any plasticizer commonly used for PVA can be used, but specific examples include ethylene glycol-μ, trimethylene glycol, tetotumethylene glycol, pentamethylene glycol, etc. , hexamethylene glycol ~, globylene glycol ~.

Glycerin, 2. S-butanedio-, 1,5-butanediol, siethi V glycol, doriethi, Renda 9
Coat sr, 19 ethylene glycol, ethylene urea,
Examples include urea, turpitou, annido rho, etc. Among these, rewetting and warmability.

Ethylene glycol and glycerin for their heat resistance.

Particularly preferred is l-lyethylene glycol having a molecular weight of 200 to 2,000.The amount of such fusing agent added is 0 to 200 parts per 100 parts by weight of Pvum. If it exceeds 200 parts, the melt viscosity of the adhesive composition decreases, making it easier to apply, but it is not preferable because the adhesive strength decreases and there is a tendency to deteriorate boot kingability.

The adhesive composition of the present invention can be prepared by adding, for example, the ◆hydric alcohol μ of PTAIC boric acid with a low degree of polymerization and low saponification, and adding a plasticizing agent as necessary and thoroughly blending the adhesive composition. It can be prepared by melting and kneading each component by heating to c. The melt prepared in this way can be directly applied to paper using a coater, etc., or it can be extruded and made into chips, then remelted before use and applied to paper using a coater, etc. You can also do it. In this case, it is particularly convenient if the adhesive composition of the present invention has a melt viscosity of about 500 to 5000 o, p, a, since a conventional nozzle type or roller type coater can be used.

The rewet hot melt adhesive composition of the present invention includes:

Other additives to the extent that the desired rewetting and adhesion properties are not lost, such as rosin resin, ethylene-vinyl acetate resin, tackifier, lubricant wax, chain additive, dye, fragrance, antioxidant, heat stabilizer. It is possible to contain an agent.

The adhesive composition of the invention is suitable for rewetting adhesives, such as envelopes, stamps, stamps, revenue stamps.

Used for Fupé μ, stamps, and wallpaper. Furthermore, since the adhesive composition of the present invention also has hot-melt properties, it can also be used for, for example, thermal paper, heat-sensitive paper, and adhesives. Furthermore, since the adhesive composition of Ta9motomei is water-soluble or water-dispersible, for example, when collecting waste paper to which it has been applied, it may cause stains on the filter, stains on the loaf, etc.
It has the advantage that there are no traps such as pinholes or spots on the product.

The present invention will be explained in more detail below by giving examples.

Note that "parts" in the nine examples mean "parts by weight."

Example 1 Degree of polymerization 120. To 100 parts of P-mum with a degree of saponification of 554 μ%, add 1 part of boric acid, Gucerine Esthes.'so.

Melt blended at 180C. This blend is 18
It exhibited an *a viscosity of 4100 o, p, s, at 0C. The adhesive composition thus obtained was melted and rolled to give a filler 1c10f/ml with a basis weight of 550 f/d.
It was applied so that it became c. This filler is made of a homogeneous liner c
＠Layered 15 x 15-, re-moistened and glued,
Pressure was applied for 10 seconds at 0.25 kl/-. When the tensile shear force of the obtained adhesive piece was measured, it was 18.7 #/
It was d. In addition, without re-wetting the stacked paper pieces with the same adhesive area, heat the sheets with an iron for 150CN and apply an adhesive pressure of 2 to 5 #/
- After crimping for 10 seconds, the tensile shear force was measured in the same way. It was Ojl, 4.

Example 2 Degree of polymerization 140. 100 parts of Pvmu with a saponification degree of 60 moles,
5 parts of glycerine ester pv of boric acid (WH product name GB-90 Toho Chemical Industry Co., Ltd.) and 80 parts of G9-9 to 18
Melt blend at 0℃, melt viscosity at 160℃ is 150
An adhesive composition of 0 o, p, s was obtained.

This product was coated on a 0.08 m thick high quality paper using a loaf coater to give a basis weight of 159/d to prepare a pasted paper. The resulting glued paper was wetted with water and bonded to another high-quality paper of the same quality, and when peeled off after 5 minutes, the paper showed adhesiveness that caused it to tear. Furthermore, when 1,000 sheets of the above glued paper were stacked and left for one month, there were no problems with curling or blocking.

Further, the above adhesive composition dissolved in cloudy water at room temperature.

Example S Degree of polymerization 80. 100 copies of P-Mum with a saponification degree of 70 p%!
The same boric acid griseon esthetics used in J Example 1.
10 parts and mediethylene glycol (molecular weight 600)
100 parts were melt-prened to obtain an adhesive composition with a melt viscosity of 1000 o, p, s at 160°C. - thickness O, Oa- high quality paper with basis weight 20
A glued paper was prepared by applying the mixture to a ratio of #/d. This pasted paper was re-moistened and pasted on another high-quality paper of the same quality, and when peeled off after 10 minutes, the paper layer showed adhesiveness that caused it to tear. Also.

I layered another high-quality paper of the same quality on the surface coated with re-wetting Amazu C.9 and heated it with a 120c iron for 10 seconds.
When it was allowed to cool for 5 seconds and then peeled off, it showed adhesiveness that caused the paper layer to tear. Also, I stacked 1000 sheets of the above glue paper and left it for a month, but there were no problems with blocking or curling! III
There wasn't. In addition, the above-mentioned adhesive knitted material was soluble in water at room temperature, and there was no problem in recovering waste paper.

Example 4 Degree of polymerization 400. 271,100 parts with a saponification degree of 55%,
umbrella? Hareno Echi V-Glyco Este μm, 0 parts Soμ Pito μ 40 parts 1 and Ethylene Glyco-μ 40 parts were melt-plane Y to obtain an adhesive composition with a melt viscosity of 5000 o, p, s at 160°C. . This paste was applied to a 0.08 g thick high-quality paper using Larco-P to give a basis weight of 25 f/d to make glued paper. The obtained pasted paper was tested for rewet adhesion and heat V-ability in the same manner as in Example 3, and both were good for 4 hours.

Also, I stacked 1,000 sheets of the above glue paper and left it for a month, but there were no problems with blocking or curling.

Furthermore, the above adhesive composition was dispersible in cloudy water at room temperature and did not pose any problem when recovering waste paper.

Patent applicant: Unitika Chemical Co., Ltd. Yosanto Kodama Haku =

Claims (1)

[Claims] (1) Degree of polymerization: 5O-5on, degree of saponification: 40-60% to excellent 4! Vinyl alcohol *100 parts by weight, ◆valent alkyl of boric acid: L-Este #0. S-ru O weight all and softener 0
- an adhesive composition consisting of 200 parts by weight. (The adhesive composition according to claim 11, wherein the adhesive composition is a ◆polarized μgoμesdelkl#! diacetate ester of paraglycic acid.