JPS5811570A - Bonding of parchment paper - Google Patents

Abstract

PURPOSE:To carry out the bonding of parchment paper in high strength even under wet conditions, by using an adhesive composed f a modified block copolymer obtained by modifying a block copolymer composed of a vinyl aromatic compound block and an olefin compound block with an unsaturated carboxylic acid. CONSTITUTION:A block copolymer containing the block of a vinyl aromatic compound (preferably styrene) and the block of an olefin compound (preferably butadiene and/or isoprene) preferably at a weight ratio of 10/90-90/10, is hydrogenated until the degree of unsaturation of the olefin compound block becomes <=20%, and an unsaturated carboxylic acid (derivative) (preferably maleic anhydride) is added to the hydrogenated product. Parchment paper is bonded using the resultant modified block copolymer as the adhesive. The amount of the unsaturated carbonxylic acid (derivative) added to the hydrogenated product is preferably 0.05-20pts.wt. per 100pts.wt. of the block copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides parchment production using a modified block copolymer obtained by modifying a Zollock copolymer consisting of a male aromatic compound block and an olefin compound block with an unsaturated caldic acid or a derivative thereof. How to glue paper K1m.

In general, parchment paper is known for its excellent dry strength,
Parchment paper is widely used as a packaging material for water-containing oils and fats due to its toughness, oil resistance, water resistance, tasteless and odorless properties, etc.However, the functionality of parchment paper as a packaging material is not always satisfied. For example, when packaging putter, margarine, etc., oil and fat content can be seen over a long period of time.As a way to compensate for such defects in a single material,
It is well known that materials with different properties can be multilayered, but in the case of parchment paper, ethylene-vinyl acetate copolymers and ionomers, which have been effectively used as adhesive layers in multilayer molded products, have traditionally been used. Resin, styrene-butadiene (9 is isoprene) block copolymer, modified? Even if lyolefin, ethylene-ethyl acrylate copolymer, etc. are used as an adhesive layer, the interlayer adhesion strength when wet is severely reduced, and a satisfactorily bonded multilayer molded product has not yet been obtained〇The present inventor In order to eliminate these drawbacks of the conventional method, we investigated the adhesion to parchment paper, especially the adhesion during temperature control, and developed a conjugated diene compound modified with unsaturated Karginsun, etc. - a vinyl aromatic compound Zolok. We proposed a method of adhesion using copolymers. (Unexamined Japanese Patent Publication No. 56-4797)
However, the block copolymer described above maintains good adhesive strength when immersed in water for about 1 to 2 hours, but has the disadvantage that the adhesive strength decreases when immersed for one day or more. As a result of further studies on techniques for more effectively adhering parchment paper, the present inventor found that the above-mentioned drawbacks could be improved by using the time-fixed polyi-i shown in the present invention, and that when immersed in water for 1 hour, The purpose of the present invention is to easily bond parchment papers to each other or parchment paper and other materials to obtain a multilayer molded product.
And to provide a method for adhering sufficiently.

That is, the present invention provides a block copolymer consisting of a vinyl aromatic compound polymer block and an olefin compound polymer block B, in which the degree of unsaturation of the block B does not exceed 20 degrees, and a carboxylic acid is added to the block copolymer. Molecular adhesive is a method of bonding parchment paper to each other or parchment paper to other materials using an adhesive based on a modified block copolymer in which molecular units containing the enzyme conductor group are bonded.

The present invention will be explained in detail below.

The parchment paper used in the present invention is sizeless cellulose paper treated with sulfuric acid or other chemicals.

In the adhesive method of the present invention, the modified block copolymer used as the adhesive can be obtained, for example, as follows. That is, the degree of unsaturation of the conjugated diene moiety of a block copolymer composed of a polymer block whose living body is a vinyl aromatic compound and a polymer block whose main body is a conjugated diene compound does not exceed 20. to 1
The unsaturated dicarmenic acid is then selectively hydrogenated with a derivative thereof to obtain a modified block copolymer.

The above block copolymer before hydrogenation contains at least one, preferably two, vinyl aromatic compound polymer blocks.
The polymer block contains at least one polymer block mainly composed of a conjugated diene compound. Here, the polymer block mainly composed of a conjugated diene has a weight ratio of a vinyl aromatic compound and a conjugated diene compound of O/100 to 501.
50, preferably from a composition range of 0/100 to 40/60, and the distribution of the vinyl aromatic compound in this block is random, tapered (increasing or decreasing monomer content along the molecular chain). things to do),
It may be partly block-like or any combination thereof◇The block copolymer before hydrogenation in the present invention mainly contains a vinyl aromatic compound polymer block and a conjugated diene compound. A copolymer of a vinyl aromatic compound and a conjugated diene compound containing more than 50% by weight of a vinyl aromatic compound may be present in the transition region between the polymer block and the conjugated diene compound. In the above block copolymer, the weight ratio of the content of the vinyl aromatic compound and the content of the conjugated diene compound is 10/
#I range of 90 to 90/10 is preferred, and 20/BO to 8
A range of V15 is more preferred.

As the vinyl aromatic compound constituting the block copolymer of the present invention, one or more of styrene, α-methylstyrene, vinyltoluene, etc. is particularly preferred, and styrene is particularly preferred.

In addition, as the conjugated diene compound, one or two of butadiene, isoprene, 1,6-pentadiene, etc.
The above block copolymer is selected from at least one species, and among them, butadiene and/or isoprene are particularly preferred.The above block copolymer has a number average molecular weight in the range of 20.000 to soo, ooo,
The molecular weight distribution (ratio of weight average molecular weight to number average molecular weight) is
The range of 1.05 to 10 is preferable. Further, the molecular structure of the block copolymer may be linear, branched, radial, or a combination thereof. Furthermore, when butadiene is used as the conjugated diene compound in the block copolymer, the amount of 1,2 bonds in the microstructure of the butadiene moiety is preferably in the range of 10 to 55-, particularly preferably in the range of 65 to 55-0. When the above block copolymer contains two or more blocks mainly composed of vinyl aromatic compounds or blocks mainly composed of conjugated diene compounds, each block may have the same structure, or the monomer components Each structure such as content, distribution in their molecular chains, molecular weight of the block, microstructure, etc. may be different.

The block copolymer of the present invention is usually prepared by combining a vinyl aromatic compound and a conjugated diene compound as monomers in an inert hydrocarbon solvent such as benzene, toluene, hexane, or chlorohexane using an organic lithium compound such as dithyllithium as a catalyst. Further, the block copolymer having a lithium active end obtained by the above method is reacted with a polyfunctional coupling agent such as carbon tetrachloride, silicon tetrachloride, etc. According to
It is also possible to form a branched or radial block copolymer. In the present invention, any polymer obtained by any polymerization method can be used as long as it is within the above range. Refreshingly, the block copolymer can be used not only as a single type but also as a mixture of two or more types.

By hydrogenating the above block copolymer by a known method, for example, the method described in Japanese Patent Publication No. 42-8704, the aromatic double bonds of the vinyl aromatic compound block are
A partially hydrogenated block copolymer is synthesized in which not more than 0% and at least 8091 of the aliphatic double bonds of the conjugated diene compound block are hydrogenated.

The degree of unsaturation of block B in the present invention refers to the proportion of carbon-carbon double bonds contained in block B, and this is determined by nuclear magnetic resonance absorption spectrum (NMR), infrared absorption spectrum (engineering The partially hydrogenated block copolymer is then modified by an addition reaction with an unsaturated carboxylic acid derivative thereof. Examples of derivatives of unsaturated carboxylic acids to be added to partially hydrogenated block copolymers include maleic acid,
maleic anhydride, fumaric acid, itaconic acid, acrylic acid,
Crotonic acid, cis-4-cyclohexene-1,2-dicarboxylic acid and its anhydride, endo-cis-bicyclo(
Examples include 2,2,1)-5-heptene-2,6-dicarboxylic acid, its anhydride, and maleimide, and among these, maleic anhydride is particularly preferred.

In the modified block copolymer of the present invention, an unsaturated carboxylic acid or its conductor is added to the base block copolymer in a solution state or a molten state, with or without the use of a radical initiator. Obtained by forcing. The method for producing these modified block copolymers is not particularly limited in the present invention, but the modified Zoroku copolymers obtained may contain undesirable components such as chlorine or have a significantly increased melt viscosity. A manufacturing method that deteriorates workability is not preferred. A preferred method is, for example, a method in which an unmodified block copolymer is reacted with an unsaturated carboxylic acid or a derivative thereof in the presence of a radical initiator in an extruder.

The amount of unsaturated carboxylic acid or its derivative added to the block copolymer is 0 per 100 parts by weight of the block copolymer.
．． 05 to 20 parts by weight is preferable, and 0.1 to 10 parts by weight is more preferable. If the amount added is 0.05 parts by weight or less, the composition will not improve, but the improvement compared to the unmodified block copolymer will be only slight, but even if the amount added exceeds 20 parts by weight,
There is almost no increase in the improvement effect compared to the unsaturated carboxylic acid or its derivative used in the present invention.4 The unsaturated carboxylic acid or its derivative used in the present invention can be used not only as a single type but also as a mixture of two or more types. The method of adhering the polymer itself is a commonly used method and is not particularly limited. That is, methods such as wet lamination, dry lamination, hot melt lamination, extrusion lamination, and hot compression bonding using a hot press can be used. may be used alone, or may be used as a compound containing ay-indene resin, petroleum hydrocarbon 1IIIr, and phenol-terpene resin.
Various resins such as ay7m4, low polymerization degree 4 listire/, and low polymerization t polybutadiene may be added alone or in a mixed system up to 100 parts per 100 parts of the modified block copolymer.

9. Ethylene-vinyl acetate copolymer, ionomer resin, styrene-butadiene (formerly isoprene) block copolymer, hydrogenated styrene-detadie (t or isoprene) Zorok copolymer, modified? Liolefin, ethyle/-ethyl acrylate copolymer, meristyrene resin,
Thermofusible resins such as polyester fin resin, natural ♂mu, synthetic ♂mu, obscuring agents, organic peroxides, antioxidants, fillers,
Ultraviolet S absorbers and the like may be added as long as the adhesion is not deteriorated.

Hereinafter, aspects of the present invention will be illustrated by some Examples, but these are for explaining the present invention in more detail and are not intended to limit the present invention. The modified block copolymer was prepared by the method described below. Contains vinyl
III1 As a moderating agent, a Zollock copolymer as shown in Part 1 was synthesized by anionic copolymerization of butadiene and styrene.

11!1 Styrene-butadiene block copolymer Next, the Zoroku copolymer shown in Table 1 was mixed in a mixed solvent of n-hexane and cyclohexane with cobalt naphthenate and triethyl aluminum as a catalyst. , hydrogen pressure 7
-/-1 Hydrogenation was carried out at a strength of 50°C for 5 hours, and about 909k of the double bond in the détagier/block part was added to Mizuki, and the benzene ring in the styrene block part was hardly hydrogenated. The remaining nine selectively hydrogenated Zoroku copolymers were synthesized. The catalyst and residual metals were removed by washing with an aqueous hydrochloric acid solution and methanol. of maleic anhydride and 0.1 parts by weight of 7Ya-Hexa 25B (Nippon Oil & Fats Co., Ltd. 1111) were mixed uniformly, and then extruded using a screwdriver* (single screw, screw diameter 20mm, under concave atmosphere). L/D m24, full flight type screw), cylinder temperature 250℃
The unreacted maleic anhydride was removed under reduced pressure from the modified Zoroku copolymer obtained by the maleation reaction at 10%, and 2.6-theter diary-dethyl-4-methylphenol was added as a stabilizer to the polymer 100. Analysis of this modified hydrogenated Zoroku copolymer containing 0.5 parts by weight per part by weight revealed that l! A result of 2 was obtained. 1) was made into a 0.5% sheet using a heat press. This sheet was sandwiched between parchment paper (manufactured by Asahi Kasei KK) and a high-density f-lyethylene sheet (Santic B4708, manufactured by Asahi Kasei KK), and heated at 120°C. Heat press for 2 minutes, 50~/1w/'
By applying pressure of The results of adjusting the flaking strength for this sheet Oal #1 are shown in Table 3.
Table 5 also clearly shows that the modified block copolymers of the present invention,
It has a bond strength of 9 (stronger when wet) than parchment lI&.

I
In the same way as u**i, use parchment paper (Asahi Kasei K
K $1) /Modified block copolymer/High Density II! 1
2 Literen (Sunlac B4708/Asahi Kasei KKII
a>(D A three-layer sheet was manufactured. eI of this three-layer sheet
Table 3 shows the measurement results of peeling strength at I114.01!
3. Clearly, the modified Zoroku copolymer of the present invention has excellent adhesion strength to parchment paper.

Example 3 Nine-modified Zoroku copolymer M (1) 10 used in Example 1
For 01!1, terpene thread resin (Y8 resin 80
50 parts (manufactured by Yaskawa Oil and Oil Co., Ltd.) were added using a roll.

In the same manner as in Example 1, using a modified block copolymer blend of Ren, parchment paper (Asahi Kasei 1c Oen)/modified Deltsk copolymer blend/Koden R/reethylene sheet (Santic Ji 4708/Asahi Kasei) A three-layer sheet made by KW was completely transparent. Table 3 shows the results of #j determination of the butterfly strength of this three-layer sheet at r11 #11. It is clear from Table 3 that the modified block copolymer blend of the present invention, in which a resin is added to the modified Zoroku copolymer, also has excellent adhesive strength (when wet) to parchment paper. Example 4 The nine-modified plotter cohesive compound obtained in Example 1 was dissolved in hot hexane, and a hexane solution of 10 weight iI kgb was prepared.
Apply this solution to a polystyrene sheet (Styro sheet, Asahi Dow KK@), and immediately stick together parchment paper and make a circle. Thereafter, a three-layer sheet was manufactured by pressing with a hand roller and releasing hexane. It is clear from Table 3, which shows the measurement results of the peel strength of this three-layer sheet when wet #S, that the modified Zoroku copolymer of the present invention has excellent adhesive strength to parchment paper. temperature control).

Comparative Example 1 Hydrogenated styrene before anhydrous maleic acid grafting of Example 1
A three-layer sheet was assembled in the same manner as in Example 1, except that a butadiene block copolymer was used as the adhesive layer. Here are the results of measuring the peeling strength of this three-layer sheet during temperature control.
6. As shown in 3 below, the water-temperature styrene-citadiene block copolymer does not have sufficient adhesion strength to parchment paper.

Comparative Example 2 Ethylene-ethyl acrylate copolymer (NtrO copolymer)
A three-layer sheet was obtained in the same manner as in Example 1, except that Rimmer DPDJ9169/Nippon Unicar 11 [) was used as the adhesive layer. Table 3 shows the measurement results of the peel strength of this three-layer sheet when wet. Shown below. As shown in Table 3, ethylene-
Ethyl acrylate copolymer wire (Barchmen) does not have sufficient adhesion strength (when wet) to paper 0 Comparative Example 5 Other companies using ionomer resin (Cobolene, Asahi Dow KKIII), A three-layer sheet was manufactured in the same manner as in Example 1. Table 3 shows the results of measuring the peel D strength of this three-layer sheet during temperature control. As shown in Table 3, the ionomer resin has sufficient adhesive strength l1 to parchment paper.
m hours) cannot be obtained.

Comparative Example 4 Styrene-butadiene block copolymer grafted with maleic anhydride (Zoroku bridge construction B-8-B-8, styrene content 38 weight-1 number average molecular weight 60.000, maleic anhydride addition amount a, 70 Weight fight, Japanese Patent Publication No. 56-4797
No., Example IKlk! A three-layer sheet was used in the same manner as in Example 1, except that Matsu-nine was used. *SK indicates the measurement results of the peeling strength of this three-layer sheet during temperature control. *As shown in 5, the modified styrene-butadiene block copolymer exhibits a significant decrease in adhesive strength when immersed in water for 24 hours (hereinafter referred to as residual color) Example 5.6 Modified block copolymer 100 parts by weight of the same hydrogenated block copolymer used in the preparation of was impregnated with 2.5 parts by weight of acrylic acid, and 0.1 parts by weight of Perhexa 25B.
After uniformly mixing, the mixture was supplied in a screw type extrusion manner under a nitrogen atmosphere, and a modification reaction was carried out at a cylinder temperature of 210°C. From the obtained modified block combination, unreacted acrylic acid was removed under reduced pressure by heating, 2.6-theter diary-dethyl-4-methylphenol was added as a stabilizer, and 100 parts by weight of the polymer Akuri Q, 5 was added. Part by weight was added.

When this modified block copolymer was analyzed, the results shown in Table 4 were obtained.Table 4 The amount of acrylic acid added was determined by determination using sodium methylate.

The adhesive strength when wet with parchment paper was measured in the same manner as in Example 1 except that O(I) and O(II) were used as the modified block copolymers and parchment paper was used as the adherend. However, the results shown in Table 5 were obtained.

Table 5 As mentioned above, when the uninvented modified block copolymer is used as an adhesive, it can be easily bonded by conventional adhesive methods such as ζ, wet lamination, r-ly lamination, hot melt lamination, extrusion lamination, and hot soresugin. It was possible to bond parchment papers together, and to obtain a bond between parchment papers or between parchment paper and other materials that had sufficient wet adhesive strength that had never been achieved in the past.

Patent applicant: Asahi Kasei Industries, Ltd.

Claims (1)

[Claims] A block copolymer consisting of a monodyl aromatic compound polymer, Derokum, and an olefin compound polymer, Deroku B, in which the lower 5N11 degrees of block 1 does not exceed 20-. A parchment characterized by an adhesive mainly composed of a modified Zoroku copolymer in which molecular units containing I phosphoric acid groups and round wire derivative groups are bonded, and is used to bond parchment papers to each other or to bond parchment paper to other materials. How to glue paper